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Sample records for blast-furnace slag cement

  1. Chloride ingress of carbonated blast furnace slag cement mortars

    NARCIS (Netherlands)

    Holthuizen, P.E.; Çopuroglu, O.; Polder, R.B.

    2017-01-01

    In the Netherlands civil engineering structures, such as overpasses, bridges and tunnels are generally built using blast furnace slag cement (BFSC, CEM III/B) concrete, because of its high resistance against chloride penetration. Although the Dutch experience regarding durability performance of BFSC

  2. X-ray diffractometry of steam cured ordinary Portland and blast-furnace-slag cements

    International Nuclear Information System (INIS)

    Camarini, G.; Djanikian, J.G.

    1994-01-01

    This work studies some aspects of the phases produced by hydration of ordinary and blast-furnace-slag cements, at normal conditions and steam cured (60 and 95 0 C), using an X-ray diffraction technique. The blast-furnace-slag cement was a mixture of 50% of ordinary Portland cement and 50% of blast-furnace-slag (separately grinding). After curing the X-ray diffraction reveals that, in relation to ordinary Portland cement, the main phases in blast-furnace-slag cement are hydrated silicates and aluminates, hydro garnet, etringitte and mono sulphate. After steam curing the hydration of blast-furnace-slag cement proceeds. This is a result of the slag activation by the curing temperature. (author). 8 refs., 3 figs., 1 tab

  3. Alkali-activated blast furnace slag-zeolite cements and concretes

    International Nuclear Information System (INIS)

    Rakhimov, R.; Rakhimova, N.

    2012-01-01

    The aim of this work has been the study of alkali-activated slag-zeolite cements and concretes based on them. Various compositions have been tested and some characteristics such as the compressive strength have been measured versus zeolite additions. A table lists the specific surface area and particle size distributions of different cements. The conclusions of the study are the following. First, alkali-activated slag cements and concretes based on them are effective for immobilization of radioactive wastes and the production of building structures, designed for high radiation load. Secondly, zeolite-containing mineral additions are able to increase the immobilization capacity and radiation resistance of alkali-activated blast furnace slag cements and concretes. Thirdly, the efficiency of different zeolite-containing additions - 10% to increase alkali-activated blast furnace slag-zeolite cement strength was established. It is with alkaline components of water-glass, sodium carbonate, sodium sulphate. Fourth, the effective way of introducing zeolite additions in alkali-activated blast furnace slag-zeolite cement is inter-grinding of the slag and addition. Increase in strength of alkali-activated blast furnace slag-zeolite cement stone is 40% higher than that of the stone of a mixture of separately milled components. Fifth, Alkali-activated blast furnace slag-zeolite cements with zeolite-containing additions with a compressive strength of 10.1 to 140 MPa; alkali-activated blast furnace slag-zeolite cements mortars with compressive strength from 35.2 to 97.7 MPa; alkali-activated blast furnace slag-zeolite cements concretes with compressive strength up to 84.5 MPa and frost resistant up to 800 cycles were obtained

  4. Composite cements containing natural pozzolan and granulated blast furnace slag

    Directory of Open Access Journals (Sweden)

    Irassar, E. F.

    2006-09-01

    Full Text Available For reasons of market demand and Portland cement production,the manufacture of cements with two or more separately ground additions to produce customized cements is becoming common practice.When pozzolan or slag content in this type of cements is high, however, the initial strength of the resulting product may be adversely impacted. This problem can be minimized by activating one or both of the replacement materials. The present study analyzes the effect of Portland cement additions such as physically activated natural pozzolan(up to 20% and/or granulated blast furnace slag (up to 35% on mortar flexural and compressive strength. The results show that higher strength is attained in ternary than binary cements. Initially (2 and 7 days, the highest compressive strengths are reached by mortars with up to 13% natural pozzolan and 5% slag, whereas at later ages mortars with larger proportions of additions are found to perform best.Debido a las exigencias del mercado y de la producción de cemento Portland, es cada vez más frecuente la elaboración de cementos con dos o más adiciones a partir de la molienda separada de sus constituyentes, dando origen a la formulación de los cementos a medida.Cuando el contenido de adiciones es alto, la utilización de puzolana y escoria en este tipo de cementos presenta la peculiaridad de disminuir la resistencia inicial del cemento resultante. Sin embargo, si algunas o ambas adiciones se activan, este problema puede minimizarse. En este trabajo se analiza la influencia de la incorporación al cemento Portland de puzolana natural (hasta 20% activada físicamente y/o escoria granulada de alto horno (hasta 35% sobre la resistencia a flexión y a compresión de morteros. Los resultados indican que los cementos ternarios presentan un mejor comportamiento resistente que los cementos binarios. Las máximas resistencias a compresión en las primeras edades (2 y 7 díasse alcanzan con hasta 13% de puzolana natural y 5% de

  5. Characteristics and propierties of oil-well cements additioned with blast furnace slag

    OpenAIRE

    Sánchez, R.; Palacios, M.; Puertas, F.

    2011-01-01

    The present paper addresses the alkali activation of Portland cements containing blast furnace slag (20 and 30% of the cement by weight) with a view to the possible use of these materials in oil well construction. The hydration studies conducted showed that in cement/slag blends, the sodium silicate activating solution partially inhibited the dissolution of the silicate phases in the Portland cement, retarding cement hydration and reducing the precipitation of reaction products. D...

  6. EFFECTS OF BLAST-FURNACE SLAG ON NATURAL POZZOLAN-BASED GEOPOLYMER CEMENT

    Directory of Open Access Journals (Sweden)

    MAHSHAD YAZDANIPOUR

    2011-03-01

    Full Text Available A number of geopolymer cement mixes were designed and produced by alkali-activation of a pumice-type natural pozzolan. Effects of blast-furnace slag on basic engineering properties of the mixes were studied. Different engineering properties of the mixes such as setting times and 28-day compressive strength were studied at different amounts of blast-furnace slag, sodium oxide content, and water-to-cement ratio. The mix comprising of 5 wt.% blast-furnace slag and 8 wt.% Na2O with a water-to-dry binder ratio of 0.30 exhibits the highest 28-day compressive strength, i.e. 36 MPa. Mixes containing 5 wt.% of ground granulated blast furnace slag showed the least efflorescence or best soundness. Laboratory techniques of X-ray diffractometry (XRD, fourier transform infrared spectroscopy (FTIR, and scanning electron microscopy (SEM were utilized for characterizing a number of mixes and studying their molecular and micro-structure. Investigations done by scanning electron microscopy confirm that smaller blast-furnace slag particles react totally while the larger ones react partially with alkaline activators and contribute to the formation of a composite microstructure.

  7. Chloride-binding Effect of Blast Furnace Slag in Cement Pastes ...

    African Journals Online (AJOL)

    Unlike previous investigations, this study attempted to make a clear distinction between the contributions of the two components in a blended cement consisting of ordinary Portland cement (OPC) and ground blast furnace slag (BFS). These contributions of each component have been quantified. Relationships between the ...

  8. Innovation based on tradition : Blast furnace slag cement for durable concrete structures in Norway?

    NARCIS (Netherlands)

    Polder, R.B.; Nijland, T.; De Rooij, M.; Larsen, C.K.; Pedersen, B.

    2014-01-01

    Blast furnace slag cement (BFSC) has been used to build reinforced concrete structures in marine and road environment in The Netherlands for nearly a century. The experience is good and structures with long service lives can be obtained, as has been shown by several field studies. This is caused by

  9. Modeling of a self-healing process in blast furnace slag cement exposed to accelerated carbonation

    NARCIS (Netherlands)

    Zemskov, S.V.; Ahmad, B.; Copuroglu, O.; Vermolen, F.J.

    2013-01-01

    In the current research, a mathematical model for the post-damage improvement of the carbonated blast furnace slag cement (BFSC) exposed to accelerated carbonation is constructed. The study is embedded within the framework of investigating the effect of using lightweight expanded clay aggregate,

  10. The use of blast furnace slag

    Directory of Open Access Journals (Sweden)

    V. Václavík

    2012-10-01

    Full Text Available The paper presents the results of experimental research that dealt with the substitution of finely ground blast furnace slag for Portland cement in the course of simple concrete manufacturing. Physical and mechanical properties of experimental concrete mixtures based on finely ground blast furnace slag were observed.

  11. Characteristics and properties of oil-well cements auditioned with blast furnace slag

    International Nuclear Information System (INIS)

    Sanchez, R.; Palacios, M.; Puertas, F.

    2011-01-01

    The present paper addresses the alkali activation of Portland cements containing blast furnace slag (20 and 30% by cement weight) with a view to the possible use of these materials in oil well construction. The hydration studies conducted showed that in cement/slag blends, the sodium silicate activator partially inhibited the dissolution of the silicate phases in the Portland cement, retarding cement hydration and reducing the precipitation of reaction products. Due to such partial inhibition, the cement/slag blends had significantly lower mechanical strength than Portland cements hydrated with water. 2 9Si and 2 7Al MAS NMR and BSE/EDX studies, in turn, showed that the CSH gel forming in the alkali-activated cement/slag pastes contained Al in tetrahedral positions and low Ca/Si ratios. (Author) 29 refs.

  12. Characteristics of Portland blast-furnace slag cement containing cement kiln dust and active silica

    Directory of Open Access Journals (Sweden)

    A. Abdel Rahman

    2016-09-01

    Full Text Available This investigation dealt with the effect of active silica, silica fume (SF or rice husk ash (RHA, on the mechanical and physico-chemical characteristics of the hardened blended cement pastes made of Portland blast-furnace slag cement (PSC containing cement kiln dust (CKD cured under normal conditions. Two blends made of PSC and CKD, improved by SF and two blends made of PSC and CKD improved by RHA were investigated. Hardened blended cement pastes were prepared from each cement blend by using water/cement ratio (W/C of 0.30 by weight and hydrated for various curing ages of 1, 3, 7, 28 and 90 days at the normal curing conditions under tap water at room temperature. Each cement paste was tested for its physico-chemical and mechanical characteristics; these characteristics include: compressive strength and kinetics of hydration. The phase composition of the formed hydration products was identified using X-ray diffraction (XRD and differential thermal analysis (DTA. It was found that the partial substitution of PSC by 10% and 15% of CKD is associated with an increase in the rate of hydration and a subsequent improvement of compressive strength of hardened PSC–CKD pastes. In addition, the replacement of PSC, in PSC–CKD blends, by 5% active silica was accompanied by further improvement of the physico-mechanical characteristics of the hardened PSC–CKD pastes.

  13. Durability and compressive strength of blast furnace slag-based cement grout for special geotechnical applications

    Directory of Open Access Journals (Sweden)

    Ortega, J. M.

    2014-03-01

    Full Text Available Special foundations, most prominently micropiles and soil anchors, are frequently used in construction today. In Spain, the grout for these special technical applications is generally prepared with portland cement, although the codes and standards in place stipulate only the minimum compressive strength required, with no mention of cement type. Those texts also establish a range of acceptable water:cement ratios. In the present study, durability and compressive strength in cement grout prepared with blast furnace slag cement at different w/c ratios are characterised and compared to the findings for a reference portland cement grout. The results show that slag grout exhibits greater durability than the portland cement material and complies with the compressive strength requirements laid down in the respective codes.Actualmente es muy frecuente el empleo de cimentaciones especiales, entre las que destacan los micropilotes y los anclajes. En España, las lechadas de cemento para estos trabajos geotécnicos especiales se preparan habitualmente con cemento Portland, aunque las diferentes normativas al respecto no restringen el tipo de cemento a emplear, siempre que se alcance una determinada resistencia a compresión. Respecto a la dosificación de las lechadas, la normativa permite emplear diferentes relaciones agua/cemento dentro de un determinado rango. En vista de ello, en este trabajo se han caracterizado las propiedades de durabilidad y resistencia a compresión de lechadas de cemento preparadas con un cemento con escoria de alto horno y con diferentes relaciones a/c, tomando como referencia de comportamiento lechadas de cemento Portland. El uso de un cemento con escoria conlleva una mejora en la durabilidad de las lechadas, cumpliendo los requisitos de resistencia a compresión establecidos por la normativa.

  14. Ternary Blends of High Aluminate Cement, Fly ash and Blast-furnace slag for Sewerage Lining Mortar

    Science.gov (United States)

    Chao, L. C.; Kuo, C. P.

    2018-01-01

    High aluminate cement (HAC), fly ash (FA) and blast-furnace slag (BFS) have been treated sustainable materials for the use of cement products for wastewater infrastructure due to their capabilities of corrosion resistance. The purpose of this study is to optimize a ternary blend of above mentioned materials for a special type of mortar for sewerage lining. By the using of Taguchi method, four control parameters including water/cementitious material ratio, mix water content, fly ash content and blast-furnace slag content were considered in nine trial mix designs in this study. By evaluating target properties including (1) maximization of compressive strength, (2) maximization of electricity resistance and (3) minimization of water absorption rate, the best possible levels for each control parameter were determined and the optimal mix proportions were verified. Through the implementation of the study, a practical and completed idea for designing corrosion resistive mortar comprising HAC, FA and BSF is provided.

  15. Characteristics and propierties of oil-well cements additioned with blast furnace slag

    Directory of Open Access Journals (Sweden)

    Sánchez, R.

    2011-06-01

    Full Text Available The present paper addresses the alkali activation of Portland cements containing blast furnace slag (20 and 30% of the cement by weight with a view to the possible use of these materials in oil well construction. The hydration studies conducted showed that in cement/slag blends, the sodium silicate activating solution partially inhibited the dissolution of the silicate phases in the Portland cement, retarding cement hydration and reducing the precipitation of reaction products. Due to such partial inhibition, the cement/slag blends had significantly lower mechanical strength than Portland cements hydrated with water. 29Si and 27Al MAS NMR and BSE/EDX studies, in turn, showed that the C-S-H gel forming in the alkali-activated cement/slag pastes contained Al in tetrahedral positions and low Ca/Si ratios.

    En el presente trabajo se ha estudiado la activación alcalina de cementos Pórtland con incorporación de escoria de horno alto (20% y 30% con respecto al peso de cemento para su posible aplicación en la construcción de pozos petrolíferos. Los estudios de hidratación realizados indican que en mezclas cemento/escoria, la disolución activadora de silicato sódico inhibe parcialmente la disolución de las fases silicato del cemento Pórtland originando un retraso de su hidratación así como la menor precipitación de productos de reacción. Dicha parcial inhibición de los procesos reactivos en las mezclas cemento/escoria originan resistencias mecánicas significativamente inferiores a las pastas de cemento Portland hidratadas con agua. Finalmente, los estudios de 29Si y 27Al RMN MAS y BSE/EDX indican que el gel C-S-H formado en pastas de mezcla cemento/escoria activadas alcalinamente presenta Al en posiciones tetraédricas y bajas relaciones Ca/Si.

  16. Early and late hydration of supersulphated cements of blast furnace slag with fluorgypsum

    Directory of Open Access Journals (Sweden)

    Bazaldúa-Medellín, M. E.

    2015-03-01

    Full Text Available The hydration, strength development and composition of hydration products of supersulphated cements were characterized from the first 48 hours up to 360 days. Two compositions of 80% Blast furnace slag, 10–15% Fluorgypsum and 10–5% Portland cement were cured in dry and wet conditions. The main hydration products were ettringite and C-S-H since the first hours and up to 360 days as evidenced by X-ray diffraction, thermal analysis and electron microscopy. The strength was favored by higher fluorgypsum contents and lower Portland cement contents. These cements generated heats of hydration of 40–57 KJ/Kg after 28 hours, which are lower than portland cement.Se realizó la caracterización de la hidratación, desarrollo de resistencia y la composición de los productos de hidratación de los cementos supersulfatados durante las primeras 48 horas y hasta 360 días. Se estudiaron dos composiciones de 80% de Escoria de alto horno, 10–15% de Fluoryeso y 10–5% de Cemento portland, se curaron en condiciones secas y húmedas. Los principales productos de hidratación fueron etringita y C-S-H desde las primeras horas y hasta 360 días, como se evidenció por difracción de rayos X, análisis térmico y microscopía electrónica de barrido. La resistencia se favoreció con mayor contenido de fluoryeso y bajos contenidos de cemento portland. Estos cementos generaron calores de hidratación de 40–57 KJ/Kg después de 28 horas, los cuales resultan más bajos que los generados por el cemento portland.

  17. Characterisation of magnesium potassium phosphate cements blended with fly ash and ground granulated blast furnace slag

    International Nuclear Information System (INIS)

    Gardner, Laura J.; Bernal, Susan A.; Walling, Samuel A.; Corkhill, Claire L.; Provis, John L.; Hyatt, Neil C.

    2015-01-01

    Magnesium potassium phosphate cements (MKPCs), blended with 50 wt.% fly ash (FA) or ground granulated blast furnace slag (GBFS) to reduce heat evolution, water demand and cost, were assessed using compressive strength, X-ray diffraction (XRD), scanning electron microscopy (SEM) and nuclear magnetic resonance (NMR) spectroscopy on 25 Mg, 27 Al, 29 Si, 31 P and 39 K nuclei. We present the first definitive evidence that dissolution of the glassy aluminosilicate phases of both FA and GBFS occurred under the pH conditions of MKPC. In addition to the main binder phase, struvite-K, an amorphous orthophosphate phase was detected in FA/MKPC and GBFS/MKPC systems. It was postulated that an aluminium phosphate phase was formed, however, no significant Al–O–P interactions were identified. High-field NMR analysis of the GBFS/MKPC system indicated the potential formation of a potassium-aluminosilicate phase. This study demonstrates the need for further research on these binders, as both FA and GBFS are generally regarded as inert fillers within MKPC

  18. Removal of Hexavalent Chromium in Portland Cement Using Ground Granulated Blast-Furnace Slag Powder

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    Sungchul Bae

    2017-12-01

    Full Text Available Using ground granulated blast-furnace slag (GGBS under different alkaline conditions, we studied the mechanisms and extents of Cr(VI reduction and sorption and compared them to reactions with Portland cement (PC. We also investigated the effects of mixing PC/GGBS ratios on Cr(VI dissolution after carbonating the substrates. We observed a complete sorption and reduction of Cr(VI to Cr(III in a GGBS-in-Ca(OH2 solution (pH > ~12.5 after 10 h, whereas in distilled water (pH = ~11.5 GGBS exhibited only marginal sorption and reduction (20%. Cr reactions with dissolved ions in supernatants derived from GGBS indicated that the anions dissolved from GGBS act as a reducing agent for Cr(VI in a Ca(OH2 solution. Soft X-ray absorption microscopy identified a partial reduction of Cr(VI to Cr(III on the GGBS surface. The carbonation of pure PC paste substantially increased the amount of dissolved Cr(VI in a solution phase whereas a 5 wt % replacement of PC with GGBS significantly reduced the amount of dissolved Cr(VI. We concluded that in the mixed paste during the early curing stage GGBS reduced a significant fraction of Cr(VI to Cr(III and that the Cr(III adsorbed in the GGBS-PC mixture’s hydration products does not readily dissolve, even under carbonation conditions.

  19. The interaction of pH, pore solution composition and solid phase composition of carbonated blast furnace slag cement paste activated with aqueous sodium monofluorophosphate

    NARCIS (Netherlands)

    Kempl, J.; Copuroglu, O.

    2015-01-01

    Blast Furnace Slag (BFS) is a waste product of industrial steel production and a common additive in the cement industry in Northern European countries. However, cementitious materials made from slag-rich cement, particularly CEM III /B, are very susceptible to carbonation. Recent investigations have

  20. Slag wool manufacturing from blast furnace slag

    Directory of Open Access Journals (Sweden)

    Володимир Петрович Руських

    2016-11-01

    Full Text Available Slag wool is the most expensive and valuable product of blast furnace slag processing. Slag wool is in great demand nowadays. The article highlights the factors influencing the mineral wool quality: chemical composition that determines the acidity of the module, the temperature of the molten slag and the required slag jet thickness consistency. Mineral wool is produced by blowing air or steam into a jet of molten slag. As a result of it the slag crushes into droplets stretching. The resulting wool contains 5% slag and 95% air. The quality of the obtained slag wool depends on the module acidity of the slag. The blast furnace slags of «Ilyich iron and steel works of Mariupol» and «Azovstal iron & steel works» are the main (short slags – they give short fibers. To obtain high-quality long fiber wool it is necessary to add admixtures into basic blast furnace slag to reduce its basicity. As a result of the fuel and energy rising prices and the necessity to reduce the slag wool cost it is necessary to develop a new technology with fiery-liquid slag, with the removal of iron compounds and sulphur from the melts and the introduction of corrective additives to improve the quality of slag wool. Good thermal conductivity (about 0,03 kcal/m∙h∙°C and other indicators (resistance, volume weight make it possible to use the materials from slag wool (pads, rigid and semi-rigid plates as heat and sound insulating materials

  1. Chloride transport testing of blast furnace slag cement for durable concrete structures in Norway : From 2 days to one year age

    NARCIS (Netherlands)

    Polder, R.B.; de Rooij, M.R.; Larsen, CK; Pedersen, B; Beushausen, H.

    2016-01-01

    Blast furnace slag cement (BFSC) has been used in reinforced concrete structures in marine and road environment in The Netherlands for nearly a century. Experience is good and long service lives can be obtained. In Norway experience with BFSC is scarce. In The Netherlands, a high resistance against

  2. Chloride transport testing of blast furnace slag cement for durable concrete structires in Norway: From 2 days to one year age

    NARCIS (Netherlands)

    Polder, R.B.; Rooij, M.R. de; Larsen, C.K.; Pedersen, B.

    2016-01-01

    Blast furnace slag cement (BFSC) has been used in reinforced concrete structures in marine and road environment in The Netherlands for nearly a century. Experience is good and long service lives can be obtained. In Norway experience with BFSC is scarce. In The Netherlands, a high resistance against

  3. Characteristics and properties of oil-well cements auditioned with blast furnace slag; Cementos petroleros con adicion de escoria de horno alto. Caracteristicas y propiedades

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, R.; Palacios, M.; Puertas, F.

    2011-07-01

    The present paper addresses the alkali activation of Portland cements containing blast furnace slag (20 and 30% by cement weight) with a view to the possible use of these materials in oil well construction. The hydration studies conducted showed that in cement/slag blends, the sodium silicate activator partially inhibited the dissolution of the silicate phases in the Portland cement, retarding cement hydration and reducing the precipitation of reaction products. Due to such partial inhibition, the cement/slag blends had significantly lower mechanical strength than Portland cements hydrated with water. {sup 2}9Si and {sup 2}7Al MAS NMR and BSE/EDX studies, in turn, showed that the CSH gel forming in the alkali-activated cement/slag pastes contained Al in tetrahedral positions and low Ca/Si ratios. (Author) 29 refs.

  4. Rheology and zeta potential of cement pastes containing calcined silt and ground granulated blast-furnace slag

    Directory of Open Access Journals (Sweden)

    Safi, B.

    2011-09-01

    Full Text Available This study aimed to analyse the re-use of dam silt as a supplementary binder for self-compacting concrete (SCC. When burnt, silt becomes more reactive because the kaolin it contains is converted into metakaolin. Portland cement, calcined or burnt silt and ground granulated blast furnace slag were used in this research. Cement pastes were prepared with blends containing two or three of these materials. The replacement ratio for burnt silt in both cases was 10 % and 20 % by cement weight and the ratio for the slag was a constant 30 % by weight of the blend. Rheological and zeta potential tests were conducted to evaluate paste electrokinetics and rheological behaviour. The findings showed that burnt silt is apt for use as an addition to cement for SCC manufacture.

    En el presente trabajo se ha analizado la posibilidad de utilizar los lodos procedentes de embalses como adición en la fabricación del hormigón autocompactante (HAC. Con la calcinación, estos materiales se vuelven más reactivos debido a la transformación en metacaolín, del caolín que forma parte de su composición. Las materias primas empleadas en esta investigación son: cemento Pórtland, lodos de embalse calcinados y escorias granuladas de horno alto. Se prepararon pastas de cemento con mezclas que contenían dos o tres de estos materiales. El porcentaje de reemplazo de los lodos calcinados osciló entre el 10 y el 20 % en peso del cemento, mientras que el de la escoria fue del 30 % en peso de la mezcla. Se llevaron a cabo ensayos reológicos y de potencial zeta para evaluar el comportamiento electrocinético y reológico de las distintas pastas. De acuerdo con los resultados obtenidos, una vez calcinados, los lodos de embalse son aprovechables como adición al cemento con destino a la preparación de HAC.

  5. EVALUATION OF THE THIXOTROPY OF OIL-WELL CEMENTS USED FOR CEMENTING LOST CIRCULATION ZONES: EFFECT OF PLASTER AND BLAST FURNACE SLAG

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    T. Bouziani

    2015-08-01

    Full Text Available Cementing of oil and gas wells can be a very delicate operation. Among the concerns of service companies, during this operation are the nature and conditions of the formations in well. This is the case of cementing operations in southern Algeria, specifically on the fields of In-Amen, where the formations in lost zones are naturally weak and highly permeable. In these areas, drilling fluids (muds and cements pumped will be, completely or partially lost, what we call "lost circulation". Thixotropic cements are useful to overcome lost circulation problems. They are characterized by a special rheological behavior, allowing it to plug lost zones when they are pumped.Our work aims to assess the thixotropy of cements perapred with two types of cement (class G Asland cement and CEM I 42.5 portland cement with the plaster, using a viscometer with coaxial cylinder (couette type. Moreover, the effect of blast furnace slag (LHF on the properties and thixotropic mixtures prepared was also studied. The results show that portland cement (available locally can produce mixes with higher and more stable thixotropy than the class G cement (from importation, which is a practical and economical for cementing job operations in wells with loss zones. The results also show that the effect of LHF is positive, since in addition to his contribution to long term performances, especially the durability of hardened concrete, it improves the thixotropy of cement made of plaster.

  6. Use of Cement Kiln Dust, Blast Furnace Slag and Marble Sludge in the Manufacture of Sustainable Artificial Aggregates by Means of Cold Bonding Pelletization

    Directory of Open Access Journals (Sweden)

    Raffaele Cioffi

    2013-07-01

    Full Text Available In this work, three different samples of solid industrial wastes cement kiln dust (CKD, granulated blast furnace slag and marble sludge were employed in a cold bonding pelletization process for the sustainable production of artificial aggregates. The activating action of CKD components on the hydraulic behavior of the slag was explored by evaluating the neo-formed phases present in several hydrated pastes. Particularly, the influence of free CaO and sulfates amount in the two CKD samples on slag reactivity was evaluated. Cold bonded artificial aggregates were characterized by determining physical and mechanical properties of two selected size fractions of the granules for each studied mixture. Eighteen types of granules were employed in C28/35 concrete manufacture where coarser natural aggregate were substituted with the artificial ones. Finally, lightweight concretes were obtained, proving the suitability of the cold bonding pelletization process in artificial aggregate sustainable production.

  7. Development of engineered cementitious composites with limestone powder and blast furnace slag

    NARCIS (Netherlands)

    Zhou, J.; Qian, S.; Sierra Beltran, M.G.; Ye, G.; Van Breugel, K.; Li, V.C.

    2009-01-01

    Nowadays limestone powder and blast furnace slag (BFS) are widely used in concrete as blended materials in cement. The replacement of Portland cement by limestone powder and BFS can lower the cost and enhance the greenness of concrete, since the production of these two materials needs less energy

  8. Greener durable concretes through geopolymerisation of blast furnace slag

    Science.gov (United States)

    Rajamane, N. P.; Nataraja, M. C.; Jeyalakshmi, R.; Nithiyanantham, S.

    2015-05-01

    The eco-friendliness of concrete is quantified by parameters such as ‘embodied energy’ (EE) and ‘embodied CO2 emission’ (ECO2e), besides duration of designed ‘service life’. It may be noted that ECO2e is also referred as carbon footprint (CF) in the literature. Geopolymer (GP) is an inorganic polymeric gel, a type of amorphous alumino-silicate product, which can be synthesised by polycondensation reactions. The concrete reported in this paper was prepared using industrial wastes in the form of blast furnace slag, fly ash as geopolymeric source materials and sodium silicate and sodium hydroxide as activators. Many mechanical properties such as compressive strength, chloride diffusion, steel corrosion, rapid chloride permeability test and rapid migration test are compared with Portland cement.

  9. The effect of blast furnace slag on the self-compactability of pumice ...

    Indian Academy of Sciences (India)

    Abstract. This paper presents the results of an experimental study of the effects of blast furnace slag, different water/(cement+mineral additive) ratios and pumice aggregates on some physical and mechanical properties of self-compacting lightweight aggregate concrete. In this study, pumice was used as lightweight ...

  10. Acid slag injection into the blast furnace tuyere zone

    Energy Technology Data Exchange (ETDEWEB)

    Haerkki, J.; Tervola, K. [Oulu Univ. (Finland). Dept. of Process Engineering

    1996-12-31

    The possibility of acid slag injection and its effect on the slag formation and on the melting behaviour of the charge materials are studied in the present work. The work is partly based on the literature evaluating the slag formation, slag properties and the basic slag injection. The possibility of acid slag injection is first examined by studying changes in the composition of the primary slag if the share of the acid slag component (Kostamus pellet/RR) of the charge material is lowered. Phase diagrams and viscosity charts are used to evaluate the viscosity, and solidus/liquidus temperature in the slag phase. The share of the slag phase of the pellet is evaluated by calculating the amount of the acid slag injection. The injection rate of some injectants is also examined. The primary slag formed of the sinter and the coke ash is in liquid form and its viscosity is close to the viscosity of the blast furnace slag. It is possible that the liquid slag phase can be formed in the blast furnace without the presence of the acid pellet because the melting point and the viscosity of the slag is lowered by alkalies, sulfur and the dissolved ironoxide of the slag. If high SiO{sub 2} content materials alone are used for injection there is a risk that the slag phase of the tuyere zone becomes too viscous. Olivine and some iron containing components such as fayalite are possible injection material. More information is needed to evaluate the effect of acid slag injection on the operation of the blast furnace. (orig.) SULA 2 Research Programme; 2 refs.

  11. A research on ceramsite obtained from blast furnace slag and ...

    African Journals Online (AJOL)

    In order to solve disposal problem of solid waste, blast furnace slag (BFS) and sewage sludge (SS) were tested as components for producing ceramsite. This study investigated the feasibility of that at different preheating and sintering temperature and duration and different mass ratios (BFS: SS: clay). The results show that ...

  12. Granulated blast furnace slag – A boon for foundry industry

    African Journals Online (AJOL)

    In the present investigation efforts have been put together to employ Granulated Blast furnace (GBF) slag as mould material for replacement of existing silica sand either full or partial in foundry industry. Nishiyama procedure was assumed for appraising the same. The process factors reflected on for this were the % of ...

  13. Soil Stabilisation Using Ground Granulated Blast Furnace Slag

    OpenAIRE

    Ashish Kumar Pathak; Dr. V. Pandey

    2014-01-01

    Stabilisation is a broad sense for the various methods employed and modifying the properties of a soil to improve its engineering performance and used for a variety of engineering works. In today‟s day soil stabilisation is the major problem for civil engineers, either for construction of road and also for increasing the strength or stability of soil and reduces the construction cost. In this thesis the soil are stabilised by ground granulated blast furnace slag (GGBS) and this material is ob...

  14. Application of encapsulated lightweight aggregate impregnated with sodium monofluorophosphate as a self-healing agent in blast furnace slag mortar

    NARCIS (Netherlands)

    Sisomphon, K.; Copuroglu, O.; Fraaij, A.

    2011-01-01

    This paper studies the potential of using expanded clay lightweight aggregate impregnated with sodium monofluorophosphate (Na2FPO3) solution which is eventually encapsulated by a cement paste layer to produce a self-healing system in blast furnace slag cement mortars. It was found that the technique

  15. The influence of blast furnace slag, fly ash and silica fume on corrosion of reinforced concrete in marine environment

    NARCIS (Netherlands)

    Polder, R.B.

    1996-01-01

    Chloride penetration from sea water may cause corrosion of reinforcement in concrete structures. Adding reactive inorganic materials such as blast furnace slag, fly ash or silica fume to the cement matrix improves the resistance against chloride penetration as compared to Portland cement concrete. A

  16. Chemical acceleration of a neutral granulated blast-furnace slag activated by sodium carbonate

    Energy Technology Data Exchange (ETDEWEB)

    Kovtun, Maxim, E-mail: max.kovtun@up.ac.za; Kearsley, Elsabe P., E-mail: elsabe.kearsley@up.ac.za; Shekhovtsova, Julia, E-mail: j.shekhovtsova@gmail.com

    2015-06-15

    This paper presents results of a study on chemical acceleration of a neutral granulated blast-furnace slag activated using sodium carbonate. As strength development of alkali-activated slag cements containing neutral GBFS and sodium carbonate as activator at room temperature is known to be slow, three accelerators were investigated: sodium hydroxide, ordinary Portland cement and a combination of silica fume and slaked lime. In all cements, the main hydration product is C–(A)–S–H, but its structure varies between tobermorite and riversideite depending on the accelerator used. Calcite and gaylussite are present in all systems and they were formed due to either cation exchange reaction between the slag and the activator, or carbonation. With accelerators, compressive strength up to 15 MPa can be achieved within 24 h in comparison to 2.5 MPa after 48 h for a mix without an accelerator.

  17. Effect of blast furnace slag on self-healing of microcracks in cementitious materials

    International Nuclear Information System (INIS)

    Huang, Haoliang; Ye, Guang; Damidot, Denis

    2014-01-01

    The physico-chemical process of self-healing in blast furnace slag cement paste was investigated in this paper. With a high slag content i.e., 66% in cement paste and saturated Ca(OH) 2 solution as activator, it was found that the reaction products formed in cracks are composed of C-S-H, ettringite, hydrogarnet and OH–hydrotalcite. The fraction of C-S-H in the reaction products is much larger than the other minerals. Large amount of ettringite formed in cracks indicates the leaching of SO 4 2− ions from the bulk paste and consequently the recrystallization. Self-healing proceeds fast within 50 h and then slows down. According to thermodynamic modeling, when the newly formed reaction products are carbonated, the filling fraction of crack increases first and then decreases. Low soluble minerals such as silica gel, gibbsite and calcite are formed. Compared to Portland cement paste, the potential of self-healing in slag cement paste is higher when the percentage of slag is high. - Highlights: • Self-healing reaction products in slag cement paste were characterized. • Self-healing reaction products formed in time were quantified with image analysis. • Self-healing in slag cement paste was simulated with a reactive transport model. • Effect of carbonation on self-healing was investigated by thermodynamic modeling. • Effect of slag on self-healing was discussed based on experiments and simulation

  18. Calcium Extraction from Blast-Furnace-Slag-Based Mortars in Sulphate Bacterial Medium

    Directory of Open Access Journals (Sweden)

    Adriana Estokova

    2018-01-01

    Full Text Available Wastewater structures, such as treatment plants or sewers can be easily affected by bio-corrosion influenced by microorganisms living in waste water. The activity of these microbes results in deterioration and can cause the reduction in structural performance of such structures. In order to improve the durability of mortar and concrete, different admixtures are being used and the best impact is observed in cement based materials combined with blast furnace slag. In this study, mortar samples with blast furnace slag were exposed to bacterial sulphate attack for 90 and 180 days. The leaching of calcium ions from the cement matrix and equivalent damaged depths of studied mortar samples were evaluated. The results showed more significant leaching of samples placed in bacterial environment, compared to the samples placed in non-bacterial environment. Similarly, the equivalent damaged depths of mortars were much higher for the bacteria-influenced samples. The slag-based cement mortars did not clearly show improved resistance in bacterial medium in terms of calcium leaching.

  19. Effect of Na3PO4 on the Hydration Process of Alkali-Activated Blast Furnace Slag

    Directory of Open Access Journals (Sweden)

    Lukáš Kalina

    2016-05-01

    Full Text Available In recent years, the utilization of different non-traditional cements and composites has been increasing. Alkali-activated cementitious materials, especially those based on the alkali activation of blast furnace slag, have considerable potential for utilization in the building industry. However, alkali-slag cements exhibit very rapid setting times, which are too short in some circumstances, and these materials cannot be used for some applications. Therefore, it is necessary to find a suitable retarding admixture. It was shown that the sodium phosphate additive has a strong effect on the heat evolution during alkali activation and effectively retards the hydration reaction of alkali-activated blast furnace slag. The aim of the work is the suggestion of a reaction mechanism of retardation mainly based on Raman and X‑ray photoelectron spectroscopy.

  20. Use of blast-furnace slag in making durable concrete for waste management repositories

    International Nuclear Information System (INIS)

    Feldman, R.F.; Beaudoin, J.J.; Philipose, K.E.

    1991-02-01

    Waste repositories for the belowground disposal of low-level radioactive waste rely greatly on the durability of concrete for their required 500-year service life. A research program is in progress based on laboratory testing of concretes containing either Type 1 cement or cements containing 65 and 75 percent of blast-furnace slag, each at 4 water-cement ratios. It has been established that the degradation of the concrete will depend on the rate of ingress of corrosive agents - chlorides, sulphate ions and CO 2 . The ionic profiles and the kinetics of diffusion of these ions in the concretes have been measured by Secondary Electron Microscope (SEM) and Energy Dispersive X-ray Analysis (EDXA) techniques, and the results plotted according to a mathematical model. Predictions for service life of the concrete have been made from this model. These predictions have been correlated with properties of the concrete obtained from micro-structural, thermochemical and permeability measurements. The improvements in concrete durability due to blast-furnace slag additions are illustrated and discussed

  1. The influence of chemical composition and fineness on the performance of alkali activated cements obtained from blast furnace slags; A influencia da composicao quimica e da finura no desempenho de cimentos alcali ativados obtidos com escorias de alto forno

    Energy Technology Data Exchange (ETDEWEB)

    Langaro, Eloise Aparecida; Matoski, Adalberto, E-mail: elolangaro@hotmail.com, E-mail: adalberto@utfpr.edu.br [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba (Brazil); Luz, Caroline Angulski da; Buth, Islas Stein; Moraes, Maryah Costa de; Pereira Filho, Jose Ilo, E-mail: angulski@utfpr.edu.br, E-mail: islas_sb@hotmail.com, E-mail: maryah_moraes@hotmail.com, E-mail: ilofilho@yahoo.com.br [Universidade Tecnologica Federal do Parana (UTFPR), Pato Branco, PR (Brazil)

    2017-01-15

    New binders are being developed for concrete in order to reduce the environmental impact mainly related to CO{sub 2} emissions. Alkali -activated cements (CATs) are obtained from lime-aluminosilicate materials and an alkali activator and can reduce by 80% the emission of CO{sub 2} compared to Portland Cement (PC). Papers have also shown physical and mechanical properties similar or higher than those presented by the PC, however, the activation of raw material is complex. Recent papers have also have showed a strong influence of the characteristics of raw material on the performance of CAT, however, little mentioned in the literature.. Therefore, this paper aimed to analyze the influence of characteristics of blast furnace slag (fineness and chemical composition) on the behavior of activated alkali cements. For this purpose, two slags were used, A and B, which were submitted to different milling times; and activated using 5% of NaOH. Mortars and pastes were prepared for compressive strength testing (7 and 28 days), measurements of heat of hydration and investigation of microstructure (XRD and DSC) were made. The results showed that the mortar made with slag A reached a very good mechanical performance, close to 48MPa at 28 days, and higher formation of CSH, in opposite of slag B. The probable hypothesis of this study is that the system formed in CAT made with slag A (containing more Al{sub 2}O{sub 3}) could provide CSH with a greater incorporation of Al and a lower crystallinity, increasing the mechanical strength. (author)

  2. The Mechanical Properties of Foamed Concrete containing Un-processed Blast Furnace Slag

    Directory of Open Access Journals (Sweden)

    Awang H.

    2014-01-01

    Full Text Available For many years, supplementary cementation materials have been utilized as cement or filler replacements to heighten the properties of concrete. The objective of this paper is to demonstrate the effects of un-processed blast furnace slag (RS on the compressive, splitting tensile and flexural strengths of foam concrete over periods of 7, 14 and 28 days. The introduction of slag to the cement begins at 30% and rises to 70% of the total content. Six mixes, which include the control mix with a similar mix ratio (1:2:0.45 and a dry density of 1300 kg/m3 is generated. Taking into consideration, from the total weight of the cementation material, 1% of super- plasticizer (PS-1 is added to the mixes with slag content. Test results revealed that the most favourable (optimum replacement level of un-processed slag in foam concrete is 30%. This represents a commercial advantage as the cement requirement is reduced from 414 Kg/m3 to 290 Kg/m3. On the 28th day, the optimum mix showed higher values than the control mix by 32% for compressive strength, 46.5% for splitting tensile strength and 61% for flexural strength.

  3. Drying shrinkage of mortars with limestone filler and blast-furnace slag

    Directory of Open Access Journals (Sweden)

    Carrasco, M. F.

    2003-12-01

    Full Text Available During the 1990's the use of cements made with port land clinker and two mineral admixtures, called ternary or blended cements, has grown considerably. Nowadays, cements containing several combinations of fly ash and silica fume, blast-furnace slag and silica fume or blast-furnace slag and limestone filler are commonly used. There are numerous works on the influence of blended cements on the fresh state and mechanical properties of mortar and concrete, but the their deformations due to drying shrinkage are not so well described. Analysis of drying shrinkage is relevant because this property influences the possibility of cracking occurrence and, hence, the deterioration of mechanical and durable properties of concrete structures. This paper evaluates the influence on the drying shrinkage of mortars of variable contents of limestone filler and/or blast-furnace slag in Portland cement. Additionally, flexion strength and non evaporable water content were evaluated. Test results show that the inclusion of these mineral admixtures, Joint or separately, increments drying shrinkage of mortars at early ages. Despite this fact, mortars made with limestone filler cement are less susceptible to cracking than mortars made with cements incorporating blast-furnace slag or both admixtures.

    Durante los años 90 el uso de cementos fabricados con clínker Portland y dos adiciones suplementarias (cementos ternarios o compuestos se ha incrementado en forma considerable. En la práctica, es cada vez más común el empleo de estos cementos conteniendo combinaciones de ceniza volante y humo de sílice, escoria y humo de sílice o escoria y filler calcáreo. En la actualidad existen numerosos estudios sobre la influencia de los cementos compuestos en las características en estado fresco y las propiedades mecánicas de morteros y hormigones, pero las deformaciones que estos materiales sufren debido a la retracción por secado no son tan conocidas. El análisis de

  4. Comparison of possibilities the blast furnace and cupola slag utilization by concrete production

    Directory of Open Access Journals (Sweden)

    D. Baricová

    2010-04-01

    Full Text Available In process of pig iron and cast iron production secondary raw materials and industrial wastes are formed The most abundant secondaryproduct originating in these processes are furnace slag. Blast furnace slag and cupola furnace slag originates from melting of gangue parts of metal bearing materials, slag forming additions and coke ash. In general, slag are compounds of oxides of metallic and non-metallic elements, which form chemical compounds and solutions with each other and also contain small volume of metals, sulfides of metals and gases. Chemical, mineralogical and physical properties of slag determinate their utilisation in different fields of industry.The paper presents results from the research of the blast furnace and cupola furnace slag utilization in the concrete production. Pilotexperiments of the concrete production were performed, by that the blast furnace and cupola furnace slag with a fractions of 0–4mm;4–8mm; 8–16mm were used as a natural substitute. A cupola furnace slag and combination of the blast furnace and cupola furnace slagwere used in the experiments. The analysis results show that such concretes are suitable for less demanding applications.

  5. Physical, chemical, and mineralogical characteristics of blast furnace slag on durability of concrete

    Directory of Open Access Journals (Sweden)

    Yogarajah Elakneswaran

    2018-01-01

    Full Text Available A partial replacement of Portland cement (PC by ground granulated blast furnace slag (GGBFS is an effective method to improve the durability of concrete due to its lower diffusivity and higher chemical resistance compared to PC. Further, the microstructure of GGBFS blended cementitious materials controls the physicochemical properties and performance of the materials in concrete. Therefore, understanding of cement hydration and cementing behavior of GGBFS is essential to establish microstructure property relationship for predicting performance. In this study, hydration, microstructure development, and chloride ingress into GGBFS-blended cement have been investigated. Solid-phase assemblage and pore solution chemistry of hydrating PC and cement blended with GGBFS were predicted using thermodynamic model and compared with experimental data. A mathematical model integrating PC hydration, GGBFS reaction, thermodynamic equilibrium between hydration products and pore solution, ionic adsorption on C-S-H, multi-component diffusion, and microstructural changes was developed to predict chloride ingress into GGBFS blended cementitious materials. The simulation results on chloride profiles for hydrated slag cement paste, which was prepared with 50% of replacement of PC with GGBFS, were compared with experimental results. The model quantitively predicts the states of chloride such as free, adsorbed on C-S-H, and chemically bound as Friedel’s salt.

  6. Interactions of Various types between Rock and Alkali-Activated Blast Furnace Slag

    Directory of Open Access Journals (Sweden)

    Mec Pavel

    2017-03-01

    Full Text Available Alkali-activated binders (AAB are very intensively studied materials nowadays. Because of possible usage as secondary raw materials, they can be environmentally efficient. Intensive research is focused especially on binder matrix, composition and its structure. For industrial usage, it is necessary to work with some aggregate for the preparation of mortars and concretes. Due to different structures of alkali-activated binders, the interaction with the aggregate will be different in comparison to an ordinary Portland cement binder. This paper deals with the study of interactions between several types of rocks used as aggregate and alkali-activated blast furnace slag. The research was focused especially on mechanical properties of prepared mortars.

  7. Green binding material using alkali activated blast furnace slag with silica fume

    Directory of Open Access Journals (Sweden)

    Mohamad Sayed

    2012-12-01

    Full Text Available Recently million tons of cement is produced in Egypt accompanied with million tons of CO2 emission which causes annually negative impact on the environment. Granulated blast furnace slag and silica fume are produced as by-product from iron and chemical industries with limited recycling facility. This paper represents an experimental study aimed to safe ferrosilicon alloy of slag and silica fume to produce cementless binding material using both of Sodium Hydroxide and water glass liquid (Sodium Silicate as alkaline activator. Experimental program was designed to study silica/slag ratio, percentage of alkali activator, water/binding ratio, incorporation of superplasticizer, and curing condition on the properties of the produced binding material. Compressive strength and mineralogical analysis were conducted on the polymeric binding material to asses the effectiveness of the main variables. The tests were divided into two stages; in the first stage compressive strength was conducted for all mixes while X-ray, microscopic scan (SEM, and infrared analysis (IR were carried out for the most pronounced promising mixes. The results showed that ratio of 25% of silica/slag is the most effective ratio and 5% of each of Sodium Hydroxide and Sodium Silicate was the optimum percentage of the alkaline activator. Additionally the use of superplasticizer is essential as it positively reduces the mixing water and maintains the binding material with acceptable workability.

  8. Effect of incorporation of fly ash and granulated blast furnace in the electrochemical behavior of concretes of commercial cement

    International Nuclear Information System (INIS)

    Gutierrez-Junco, O. J.; Pineda-Triana, Y.; Vera-Lopez, E.

    2015-01-01

    This paper presents the findings of the research properties evaluation pastes of commercial cement (CPC), mixed with fly ash (FA) and granulated blast furnace slag (GBFS). Initially, the sample of 30 combinations were evaluated in terms of compressive strength to establish the optimal proportions from raw material. After that, four optimized blends were characterized during the setting and hardening process. Electrochemical tests were performed on concrete cylinders samples prepared with cementitious materials and a structural steel rod placed in the center of the specimen. With the objective to evaluate the performance before corrosion, thermodynamic and kinetic aspects were taken into consideration. The findings showed that commercial cements blended with fly ash and blast furnace slag as the ones used in this research presents a decreased behavior in mechanical and corrosion strength regarding to CPC. (Author)

  9. Hydration Properties of Ground Granulated Blast-Furnace Slag (GGBS Under Different Hydration Environments

    Directory of Open Access Journals (Sweden)

    Shuhua LIU

    2017-02-01

    Full Text Available The hydration properties of various cementitious materials containing Ground Granulated Blast-furnace Slag (GGBS, two alkali-activated slag cements (AAS-1 and AAS-2 in which sodium silicate and sodium hydroxide act as alkaline activators respectively, supersulfated cement (SSC and slag Portland cement(PSC, are compared with ordinary Portland cement (OPC to investigate the effect of activating environment on the hydration properties in this study by determining the compressive strength of the pastes, the hydration heat of binders within 96 hours, and the hydration products at age of 28 days. The results show that C-S-H gels are the main hydrated products for all cementitious systems containing GGBS. Ca(OH2 is the hydration products of OPC and PSC paste. However, ettringite and gypsum crystals instead of Ca(OH2 are detected in SSC paste. Additionally, tobermorite, a crystalline C-S-H, and calcite are hydrated products in AAS-1. Tobermorite, cowlesite and calcite are hydrated products of AAS-2 as well. Based on strength results, AAS-1 paste exhibits the highest compressive strength followed by POC, PSC, SSC in order at all testing ages and AAS-2 give the lowest compressive strength except for the early age at 3 days, which is higher than SSC but still lower than PSC. From hydration heat analysis, alkalinity in the reaction solution is a vital factor influencing the initial hydration rate and the initial hydration rate from higher to lower is AAS-2, AAS-1, OPC, PSC and SSC. Although AAS possesses a faster reaction rate in the initial hours, cumulative hydration heat of AAS is comparably lower than that of OPC, but higher than those of PSC and SSC in turn, which indicates that the hydration heat of clinkers is much higher than that of slag.DOI: http://dx.doi.org/10.5755/j01.ms.23.1.14934

  10. Kinetics and physico-chemical properties of alkali activated blast-furnace slag/basalt pastes

    Directory of Open Access Journals (Sweden)

    H. El Didamony

    2012-12-01

    Full Text Available Granulated blast-furnace slag (GBFS is a by-product of the metallurgical industry and consists mainly of lime and calcium–magnesium aluminosilicates that defined as the glassy granular material formed by rapid cooling of molten slag with excess water resulting in an amorphous structure. Alkali-activated slag (AAS binders have taken a great interest from researchers due to its manufacturing process which has important benefits from the point of view of the lower energy requirements and lower emission of greenhouse gases with respect to the manufacturing of Portland cement. In this study, GBFS was replaced by 20, 40 and 60 wt.% of basalt activated by 6 wt.% of alkali mixture composed of 1:1 sodium hydroxide (SH and liquid sodium silicate (LSS mixed with sea water and cured in 100% relative humidity up to 90 days. The physic-chemical parameters were studied by determination of setting time, combined water content, bulk density and compressive strength. As the amount of basalt increases the setting time as well as compressive strength decreases while the bulk density increases. The compressive strength values of dried pastes are greater than those of saturated pastes. The hydrated products are identified by TGA/DTG analysis, IR spectroscopy and scanning electron microscopy (SEM.

  11. Granulated blast furnace slag – A boon for foundry industry | Murthy ...

    African Journals Online (AJOL)

    In the present investigation efforts have been put together to employ Granulated Blast furnace (GBF) slag as mould material for replacement of existing silica sand either full or partial in foundry industry. Nishiyama procedure was assumed for appraising the same. The process factors reflected on for this were the % of ...

  12. Magnesium alloys and graphite wastes encapsulated in cementitious materials: Reduction of galvanic corrosion using alkali hydroxide activated blast furnace slag

    International Nuclear Information System (INIS)

    Chartier, D.; Muzeau, B.; Stefan, L.; Sanchez-Canet, J.; Monguillon, C.

    2017-01-01

    Highlights: • Embedded in cement, magnesium is corroded by residual water present in porosity of the matrix. • Corrosion is enhanced by galvanic phenomenon when magnesium is in contact with graphite. • Galvanic corrosion of magnesium in contact with graphite debris is shown to be severe with ordinary Portland cement. • Galvanic corrosion is significantly lowered in high alkali medium such as sodium hydroxide. • Sodium hydroxide activated blast furnace slag is a convenient binder to embed magnesium. - Abstract: Magnesium alloys and graphite from spent nuclear fuel have been stored together in La Hague plant. The packaging of these wastes is under consideration. These wastes could be mixed in a grout composed of industrially available cement (Portland, calcium aluminate…). Within the alkaline pore solution of these matrixes, magnesium alloys are imperfectly protected by a layer of Brucite resulting in a slow corrosion releasing hydrogen. As the production of this gas must be considered for the storage safety, and the quality of wasteform, it is important to select a cement matrix capable of lowering the corrosion kinetics. Many types of calcium based cements have been tested and most of them have caused strong hydrogen production when magnesium alloys and graphite are conditioned together because of galvanic corrosion. Exceptions are binders based on alkali hydroxide activated ground granulated blast furnace slag (BFS) which are presented in this article.

  13. Magnesium alloys and graphite wastes encapsulated in cementitious materials: Reduction of galvanic corrosion using alkali hydroxide activated blast furnace slag

    Energy Technology Data Exchange (ETDEWEB)

    Chartier, D., E-mail: david.chartier@cea.fr [Commissariat à l' Energie Atomique et aux Energies Alternatives, CEA, DEN, DTCD, SPDE, F-30207 Bagnols-sur-Cèze (France); Muzeau, B. [DEN-Service d’Etude du Comportement des Radionucléides (SECR), CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette (France); Stefan, L. [AREVA NC/D& S - France/Technical Department, 1 place Jean Millier 92084 Paris La Défense (France); Sanchez-Canet, J. [Commissariat à l' Energie Atomique et aux Energies Alternatives, CEA, DEN, DTCD, SPDE, F-30207 Bagnols-sur-Cèze (France); Monguillon, C. [DEN-Service d’Etude du Comportement des Radionucléides (SECR), CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette (France)

    2017-03-15

    Highlights: • Embedded in cement, magnesium is corroded by residual water present in porosity of the matrix. • Corrosion is enhanced by galvanic phenomenon when magnesium is in contact with graphite. • Galvanic corrosion of magnesium in contact with graphite debris is shown to be severe with ordinary Portland cement. • Galvanic corrosion is significantly lowered in high alkali medium such as sodium hydroxide. • Sodium hydroxide activated blast furnace slag is a convenient binder to embed magnesium. - Abstract: Magnesium alloys and graphite from spent nuclear fuel have been stored together in La Hague plant. The packaging of these wastes is under consideration. These wastes could be mixed in a grout composed of industrially available cement (Portland, calcium aluminate…). Within the alkaline pore solution of these matrixes, magnesium alloys are imperfectly protected by a layer of Brucite resulting in a slow corrosion releasing hydrogen. As the production of this gas must be considered for the storage safety, and the quality of wasteform, it is important to select a cement matrix capable of lowering the corrosion kinetics. Many types of calcium based cements have been tested and most of them have caused strong hydrogen production when magnesium alloys and graphite are conditioned together because of galvanic corrosion. Exceptions are binders based on alkali hydroxide activated ground granulated blast furnace slag (BFS) which are presented in this article.

  14. CONTACT STRENGTH OF MECHANOACTIVATED FINE CONCRETES FROM GRANULATED BLAST-FURNACE SLAGS

    Directory of Open Access Journals (Sweden)

    V. I. Bolshakov

    2014-10-01

    Full Text Available Purpose. Strengthening of fine concrete contact zone by mechanical processing of all components of the concrete mix in a mixer-activator and aggregate application with rough surface. Methodology. Rotary activator PC-06, developed by Scientific and Research Institute of Construction Technology, was used as a mixer-activator to achieve this purpose. Granulated blast furnace slag, having a more developed rough surface than sand, was used as fine aggregate. This apparatus provides intensive homogeneous mixing of concrete mix components, processing of raw materials (purification of their particles from contaminants, and mechanical destruction of granulated blast furnace slag surface layers and other components of the mix. Findings. During the preparation work, experimental research of new formations composition of fine concretes, using differential thermal and x-ray phase analysis methods, and physical-mechanical properties of fine concretes in accordance with the applicable standards of Ukraine, were carried out. It is established that the phase composition of new formations of fine concretes made from activated and non-activated mixes, is not changed. Their main difference is the size of generated effects and temperature intervals of occurrence of these peaks. Thus, in fine concretes made on the basis of the activated mixes, magnitude of effects is less, indicating a higher hydration degree of its components. Besides, TG curves of concrete specimens show that weight loss of gel calcium hydrosilicate of concrete from a mechanically activated mix is 0.5...0.7 % more than of concrete from a non-activated mix, which indicates a larger number of these formations in concrete from activated mixes. In general, concretes of different composition, made from a mix, processed in the mixer-activator, have higher mechanical strength. Originality. Ideas about the influence of mechanical activation of components of fine concrete mixes with forming humidity in a

  15. Forensic Investigation of AC and PCC Pavements with Extended Service Life : Volume 3 : Petrographic Examination of Blast Furnace Slag Aggregate Concrete Cores taken from PCC Pavements in Cuyahoga County , Ohio : Executive Summary Report

    Science.gov (United States)

    2010-09-01

    Air-cooled blast furnace slag has been used as a coarse : aggregate in portland cement-based pavement concretes : since at least the early 1900s. Many of these concretes : have performed satisfactorily. In recent times a number : of PCC slag aggre...

  16. Ground granulated blast furnace slag efficiency coefficient (k value) in concrete. Applications and limits

    International Nuclear Information System (INIS)

    Sanjuan, M. A.; Pineiro, A.; Rodriguez, O.

    2011-01-01

    Recently, a k-value for ground granulated blast-furnace slag or k-value has been added to the revision of the European standard EN 206-1:2000. The proposed values during the discussions in the working groups were very different because in most of cases the compressive strength was the only characteristic considered; while only in few cases the concrete durability was taken into account when ground granulated blast-furnace slag is added directly to the mix. Advantages and disadvantages of the k-values found in the literature are discussed in this paper. The final conclusion may be summarised suggesting a logical proposal of addressing to each country the choice of the k-value in function of the concrete application, environment and placing conditions selected according to their own experience. (Author) 15 refs.

  17. Ground granulated blast furnace slag efficiency coefficient (k value) in concrete. Applications and limits

    Energy Technology Data Exchange (ETDEWEB)

    Sanjuan, M. A.; Pineiro, A.; Rodriguez, O.

    2011-07-01

    Recently, a k-value for ground granulated blast-furnace slag or k-value has been added to the revision of the European standard EN 206-1:2000. The proposed values during the discussions in the working groups were very different because in most of cases the compressive strength was the only characteristic considered; while only in few cases the concrete durability was taken into account when ground granulated blast-furnace slag is added directly to the mix. Advantages and disadvantages of the k-values found in the literature are discussed in this paper. The final conclusion may be summarised suggesting a logical proposal of addressing to each country the choice of the k-value in function of the concrete application, environment and placing conditions selected according to their own experience. (Author) 15 refs.

  18. Potential modification of hydration of alkali activated mixtures from granulated blast furnace slag and fly ash

    Czech Academy of Sciences Publication Activity Database

    Tomková, V.; Ovčačík, F.; Vlček, J.; Ovčačíková, H.; Topinková, M.; Vavro, M.; Martinec, Petr

    2012-01-01

    Roč. 56, č. 2 (2012), s. 168-176 ISSN 0862-5468 R&D Projects: GA ČR GA106/09/0588 Institutional support: RVO:68145535 Keywords : alkali-activated materials * blast furnace slag * mechanical activation * fly ash Subject RIV: DD - Geochemistry Impact factor: 0.418, year: 2012 http://www.ceramics-silikaty.cz/2012/pdf/2012_02_168.pdf

  19. Effect of air-cooled slag and granulated blast furnace slag addition as substitutor on fly ash based geopolymer

    Science.gov (United States)

    Harmaji, Andrie; Imran, Aishah Mahyarni; Sunendar, Bambang; Lazuardi, Muhammad Sofyan; Khairunnasari, Ikhsan; Sobandi, Ahmad

    2017-09-01

    Air Cooled Slag and Granulated Blast Furnace Slag is a waste material from steelmaking process that not utilized, even though it rich in silica and CaO that can increase mechanical properties of building materials. Therefore, this material is potential as substitutor for geopolymer. Geopolymer is an alkali activated material consists of aluminosilicate precursor activated by NaOH and waterglass as activator. One of the common aluminosilicate binder used is fly ash. Geopolymer was made by mixing fly ash and air cooled slag or granulated blast furnace slag in certain ratio with alkali activator solution. The aim for this study is to obtain the best ratio of slag to fly ash binder that produces the highest compressive strength. The best compressive strength was 29.80 MPa achieved in fly ash:air cooled slag 40:60 ratio and 31.33 MPa achieved in fly ash:granulated blast furnace slag 40:60 ratio. X-Ray Diffraction test showed the appearance of anorthite (Ca, Na (Al, Si)4 O8). FTIR characterization showed the appearance of siloxo and sialate bonding which commonly found in geopolymerization.

  20. Mechanical behaviour of alkali-activated blast furnace slag-activated metakaolin blended pastes. Statistical study

    Directory of Open Access Journals (Sweden)

    Higuera, I.

    2012-06-01

    Full Text Available The study and development of alternative, more ecoefficient binders than portland cement are attracting a good deal of scientific and technological interest. Binders obtained from the chemical interaction between calcium silico-aluminous materials and highly alkaline solutions are one of several types of such possible cements. The present paper discusses the mechanical behaviour and mineralogical composition of blended pastes made from NaOH-activated vitreous blast furnace slag and metakaolin. The aim of the study was to determine how parameters such as the slag/metakaolin ratio, activating solution concentration and curing temperature affect strength development in these binders. A statistical study was conducted to establish the impact of each variable and model strength behaviour in these alkaline cements. The conclusion drawn is that activator concentration and the slag/metakaolin ratio are both determinant parameters.

    El estudio y desarrollo de cementos alternativos y más eco-eficientes que el cemento Portland es un tema de gran impacto a nivel científico y tecnológico. Entre esos posibles cementos se encuentran los cementos alcalinos que son materiales conglomerantes obtenidos por la interacción química de materiales silico-aluminosos cálcicos y disoluciones fuertemente alcalinas. En el presente trabajo se estudia el comportamiento mecánico y la composición mineralógica de mezclas de escoria vítrea de horno alto y metacaolín activadas alcalinamente con disoluciones de NaOH. El objetivo de este estudio es conocer cómo afectan parámetros tales como la relación escoria/metacaolín, la concentración de la disolución activadora y la temperatura de curado, al desarrollo resistente de las mezclas. A través del estudio estadístico realizado se ha podido establecer la influencia de cada variable y modelizar el comportamiento resistente de estos cementos alcalinos. Se concluye que la concentración del activador y la relaci

  1. Application of Ground Granulate Blast Furnace Slag-Steel Slag Composite Binder in a Massive Concrete Structure under Severe Sulphate Attack

    Directory of Open Access Journals (Sweden)

    Jin Liu

    2017-01-01

    Full Text Available A composite mineral binder was prepared by mixing ground granulate blast furnace slag (GGBS and steel slag (GGBS/steel slag ratios are 1 : 1 or 3 : 2 by mass. The application of a composite binder in a massive concrete structure under severe sulphate attack is discussed by determining the hydration heat, adiabatic temperature increase, compressive strength, elastic modulus, chloride ion permeability, and sulphate attack resistance. The results show that the hydration heat of the composite binder decreases greatly when the cement replacement ratio increases to 50% at 45°C. The adiabatic temperature rise of the concrete containing the composite mineral admixture decreases significantly. Concrete containing the composite mineral admixture has a lower early elastic modulus and satisfactory late-age compressive strength. The composite mineral admixture can improve the resistance to chloride ion permeability and sulphate attack resistance of concrete, especially during temperature match curing.

  2. Plant Growth and Water Purification of Porous Vegetation Concrete Formed of Blast Furnace Slag, Natural Jute Fiber and Styrene Butadiene Latex

    Directory of Open Access Journals (Sweden)

    Hwang-Hee Kim

    2016-04-01

    Full Text Available The purpose of this study is to investigate porous vegetation concrete formed using the industrial by-products blast furnace slag powder and blast furnace slag aggregates. We investigated the void ratio, compressive strength, freeze–thaw resistance, plant growth and water purification properties using concretes containing these by-products, natural jute fiber and latex. The target performance was a compressive strength of ≥12 MPa, a void ratio of ≥25% and a residual compressive strength of ≥80% following 100 freeze–thaw cycles. Using these target performance metrics and test results for plant growth and water purification, an optimal mixing ratio was identified. The study characterized the physical and mechanical properties of the optimal mix, and found that the compressive strength decreased compared with the default mix, but that the void ratio and the freeze–thaw resistance increased. When latex was used, the compressive strength, void ratio and freeze–thaw resistance all improved, satisfying the target performance metrics. Vegetation growth tests showed that plant growth was more active when the blast furnace slag aggregate was used. Furthermore, the use of latex was also found to promote vegetation growth, which is attributed to the latex forming a film coating that suppresses leaching of toxic components from the cement. Water purification tests showed no so significant differences between different mixing ratios; however, a comparison of mixes with and without vegetation indicated improved water purification in terms of the total phosphorus content when vegetation had been allowed to grow.

  3. Leaching of Metal Ions from Blast Furnace Slag by Using Aqua Regia for CO2 Mineralization

    OpenAIRE

    Jun-Hwan Bang; Seung-Woo Lee; Chiwan Jeon; Sangwon Park; Kyungsun Song; Whan Joo Jo; Soochun Chae

    2016-01-01

    Blast furnace slag (BFS) was selected as the source of Ca for CO2 mineralization purposes to store CO2 as CaCO3. BFS was dissolved using aqua regia (AR) for leaching metal ions for CO2 mineralization and rejecting metal ions that were not useful to obtain pure CaCO3 (as confirmed by XRD analysis). The AR concentration, as well as the weight of BFS in an AR solution, was varied. Increasing the AR concentration resulted in increased metal ion leaching efficiencies. An optimum concentration of 2...

  4. Static Holdup of Liquid Slag in Simulated Packed Coke Bed Under Oxygen Blast Furnace Ironmaking Conditions

    Science.gov (United States)

    Wang, Guang; Liu, Yingli; Zhou, Zhenfeng; Wang, Jingsong; Xue, Qingguo

    2018-01-01

    The liquid-phase flow behavior of slag in the lower zone of a blast furnace affects the furnace permeability, performance, and productivity. The effects of pulverized coal injection (PCI) on the behavior of simulated primary slag flow were investigated by quantifying the effect of key variables including Al/Si ratio [Al2O3 (wt.%) to SiO2 (wt.%)] and the amount of unburnt pulverized coal (UPC) at 1500°C. Viscosity analysis demonstrated that the slag fluidity decreased as the Al/Si ratio was increased (from 0.35 to 0.50), resulting in gradual increase of the static holdup. Increasing the amount of UPC resulted in a significant increase of the static holdup. Flooding analysis was applied to determine the maximum static holdup, which was found to be 11.5%. It was inferred that the burnout rates of pulverized coal should exceed 78.6% and 83.9% in traditional and oxygen blast furnaces, respectively.

  5. Natural pozzolan-and granulated blast furnace slag-based binary geopolymers

    Directory of Open Access Journals (Sweden)

    Robayo, R. A.

    2016-03-01

    Full Text Available This study describes the synthesis at ambient temperature (25±3 °C of binary geopolymer systems based on natural volcanic pozzolan and granulated blast furnace slag. Na2SiO3 and NaOH were used as alkaline activators. The effects of the SiO2/Al2O3, Na2O/Al2O3 ratio and the amount of slag added (from 0 to 30% on the reaction kinetics, compressive strength and microstructure of the final product were studied. To characterise the geopolymer pastes, techniques such as X-ray diffraction (XRD, infrared spectroscopy (FTIR and scanning electron microscopy (SEM were used. The results indicate the possibility of obtaining a geopolymer cement with a compressive strength of up to 48.11 MPa after 28 days of curing at ambient temperature whose characteristics are comparable to those of commercial portland cement.Este trabajo describe la síntesis a temperatura ambiente (25±3 °C de sistemas geopoliméricos de tipo binario basados en una puzolana natural de origen volcánico y escoria siderúrgica de alto horno usando activadores alcalinos basados en la combinación de Na2SiO3 y NaOH. Se estudió el efecto de la relación SiO2/Al2O3, Na2O/Al2O3 y la cantidad de escoria adicionada en niveles entre el 0 y 30% sobre la cinética de reacción, la resistencia a la compresión y la microestructura del producto final. Para la caracterización de las pastas geopoliméricas se utilizaron técnicas como difracción de rayos X (DRX, espectroscopia infrarroja (FTIR y microscopia electrónica de barrido (MEB. Los resultados conseguidos revelan la posibilidad de obtener un cementante geopolimérico con una resistencia a la compresión de hasta 48,11 MPa a los 28 días de curado a temperatura ambiente cuyas características son comparables a las de un cemento portland comercial.

  6. Carbothermic Reduction Reactions at the Metal-Slag Interface in Ti-Bearing Slag from a Blast Furnace

    Science.gov (United States)

    Wang, Yao-Zu; Zhang, Jian-Liang; Liu, Zheng-Jian; Du, Cheng-Bo

    2017-11-01

    Carbothermic reduction reactions at the metal-slag interface and the mechanisms of iron loss during the smelting of vanadium-bearing titanomagnetite in a blast furnace are still not clear as a result of the limited ability to observe the high-temperature zone of a blast furnace. The chemical composition of a Ti-bearing slag was determined by x-ray fluorescence and x-ray diffraction. The interfaces were characterized by scanning electron microscopy coupled with energy-dispersive x-ray spectroscopy. The interfacial chemical reactions were deduced based on the characterization results and on the thermodynamic calculations performed using Factsage 6.4. The results indicated that the forms of iron in the slag were iron droplets wetted by Ti(C x , N1- x ), mechanically separated by iron and iron oxide. The different forms possessed unique characteristics and were formed by different mechanisms. Iron droplets wetted by Ti(C x , N1- x ) were generated through a series of interfacial reactions between TiO2 in the slag and [C] and [N] in the metal. Iron droplets without attached Ti(C x , N1- x ) were mainly located on the edges of pores and were attributed to the reduction of Fe x O in the slag. Insufficient reduction of iron-bearing minerals made it difficult for iron droplets to aggregate and separate from the slag, which created an Fe x O-enriched zone.

  7. Sulphate removal over barium-modified blast-furnace-slag geopolymer.

    Science.gov (United States)

    Runtti, Hanna; Luukkonen, Tero; Niskanen, Mikko; Tuomikoski, Sari; Kangas, Teija; Tynjälä, Pekka; Tolonen, Emma-Tuulia; Sarkkinen, Minna; Kemppainen, Kimmo; Rämö, Jaakko; Lassi, Ulla

    2016-11-05

    Blast-furnace slag and metakaolin were geopolymerised, modified with barium or treated with a combination of these methods in order to obtain an efficient SO4(2-) sorbent for mine water treatment. Of prepared materials, barium-modified blast-furnace slag geopolymer (Ba-BFS-GP) exhibited the highest SO4(2-) maximum sorption capacity (up to 119mgg(-1)) and it compared also favourably to materials reported in the literature. Therefore, Ba-BFS-GP was selected for further studies and the factors affecting to the sorption efficiency were assessed. Several isotherms were applied to describe the experimental results of Ba-BFS-GP and the Sips model showed the best fit. Kinetic studies showed that the sorption process follows the pseudo-second-order kinetics. In the dynamic removal experiments with columns, total SO4(2-) removal was observed initially when treating mine effluent. The novel modification method of geopolymer material proved to be technically suitable in achieving extremely low concentrations of SO4(2-) (<2mgL(-1)) in mine effluents. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Repulsion forces of superplasticizers on ground granulated blast furnace slag in alkaline media, from AFM measurements to rheological properties

    OpenAIRE

    Palacios, M.; Bowen, P.; Kappl, M.; Butt, H. J.; Stuer, M.; Pecharromán, C.; Aschauer, U.; Puertas, F.

    2012-01-01

    The electrostatic and steric repulsion induced by different superplasticizers on ground granulated blast furnace slag in alkaline media have been studied. The superplasticizers were sulfonated naphthalene, sulfonated melamine, vinyl copolymer, and polycarboxylate- based admixtures. With these superplasticizers the slag suspensions had negative zeta potentials, ranging from -3 to -10 mV. For the first time the adsorbed layer thicknesses for superplasticizers on slag using colloidal probe atomi...

  9. Analysis of the Rheological Behaviour of Selected Semi-Solid Slag Systems in Blast Furnace Flow Conditions

    Directory of Open Access Journals (Sweden)

    Migas P.

    2015-04-01

    Full Text Available The rheological properties of liquid and semi-solid systems of slag and hot metal in a blast furnace are extremely important from the perspective of their dripping in the unit. The rheological nature and the values of the dynamic viscosity coefficient of liquid and semi-solid phases - slag and hot metal - determine the permeability of the zones in which those systems exist. The modelling of dripping processes and e.g. static and dynamic holding/retention of liquid in the bed, requires an accurate description of the rheological behaviour of slag and iron systems. Determining the liquid flow through the lump bed of the blast furnace is based on the assumption that liquids in the unit in the whole range of their occurrence are similar to a Newtonian ideal liquid. This study presents an analysis of the findings of high-temperature rheometric measurements of CaO-SiO2-Al2O3-MgO systems, liquid, semi-solid slags of the blast furnace type doped with TiO2 and solids in the form of TiN. The tests were performed within a temperature range of 1310-1490°C. Also measurement results for glycerol solutions with concentrations of 86% and 100% at the ambient temperature, simulating blast furnace slags with various contents of solids - PC, anthracite - are presented.

  10. Stabilisation of erodible soil by fly ash and blast furnace slag

    Energy Technology Data Exchange (ETDEWEB)

    Indraratna, B.; Salim, W. [Civil Engineering Division, University of Wollongong, N.S.W., Wollongong (Australia)

    2000-07-01

    Residual soils are found on large terrains which are often subjected to considerable erosion. This paper presents a detailed laboratory evaluation of the effect of fly ash and blast furnace slag on two different soils: (a) culluvium (sandy loam) from New South Wales, Australia and (b) erodible dispersive clay from northeast Thailand. Geotechnical tests were conducted to determine the compaction characteristics and the compressive and shear strength properties of the blended and natural soil specimens. The effect of the above mentioned industrial wastes on the rate of erosion and on the associated pH levels is also investigated. Fine grained fly ash is found to be useful as a void filler if used in substantial quantities, whereas selfhardening milled slag is more effective in terms of improving the internal friction angle of the treated soil. 18 refs.

  11. Effect of the Basicity on the Crystallization Behavior of Titanium Bearing Blast Furnace Slag

    Science.gov (United States)

    Meilong, Hu; Ruirui, Wei; Leizhang, Gao; Lu, Liu; Chenguang, Bai

    2018-03-01

    Basicity of titanium bearing blast furnace (BF) slag is critical for its crystallization behavior. Thermodynamics calculation indicates that rutile is the main phase after crystallization (or at room temperature). It precipitates during the cooling when the basicity of the slag is lower than 0.7. With increasing basicity, perovskite appears and becomes the main phase instead which contains titanium. Crystallization temperature of perovskite is higher than that of rutile and the other phases. Namely, perovskite crystallizes firstly from the molten slag during decreasing temperature. XRD analysis shows that CaTi21O38 is the main phase with a basicity of 0.6. CaMg0.39Al0.87Ti0.48Si1.26O6, CaTiSiO5 and CaMgSi2O6 are the main crystallization phases with a basicity of 0.8. The difference between experimental and thermodynamics calculation is due to the complicate crystallization behavior of the multiple slag under super cooling rate. When the slag basicity increases to 1.1, the main precipitatied phase is perovskite, which agrees well with theory calculation. In addition, the crystal structure of the synthesized titanium bearing slag is basically similar regardless of the basicity.

  12. Correlation of the Processing Parameters in the Formation of Granulated Ground Blast Furnace Slag Geopolymer

    Science.gov (United States)

    Aziz, I. H.; Abdullah, M. M. A. B.; Yong, H. C.; Ming, L. Y.; Panias, D.; Sakkas, K.

    2017-06-01

    Geopolymers are inorganic materials with huge potential applications including building material, fire resistant materials, and agricultural construction materials. Various parameters influenced the final properties of these geopolymer concretes. This study developed the effects of several factors such as solid-to-liquid ratio, NaOH concentration, and Na2SiO3/NaOH ratio on the compressive strength of granulated ground blast furnace slag (GGBFS) by statistical design of experiment (DOE) approach. Analysis of the experimental results through ANOVA exhibited that the specimen with NaOH concentration of 10M, Na2SiO3/NaOH ratio equals to 2.5, and solid-to-liquid ratio of 3.0 curing at room temperatures for 28 days was potential of highest strength (168.705 MPa) in the considered procedure. Besides, the relationship between compressive strength and influential factors could be suitably by fraction factorial design method.

  13. Thermodynamic Analysis of Blast Furnace Slag Waste Heat-Recovery System Integrated with Coal Gasification

    Science.gov (United States)

    Duan, W. J.; Li, P.; Lei, W.; Chen, W.; Yu, Q. B.; Wang, K.; Qin, Q.

    2015-05-01

    The blast furnace (BF) slag waste heat was recovered by an integrated system stage by stage, which combined a physical and chemical method. The water and coal gasification reactions were used to recover the heat in the system. Based on the first and second law of thermodynamics, the thermodynamic analysis of the system was carried out by the enthalpy-exergy diagram. The results showed that the concept of the "recovery-temperature countercurrent, energy cascade utilization" was realized by this system to recover and use the high-quality BF slag waste heat. In this system, the high-temperature waste heat was recovered by coal gasification and the relatively low-temperature waste heat was used to produce steam. The system's exergy and thermal recycling efficiency were 52.6% and 75.4%, respectively. The exergy loss of the integrated system was only 620.0 MJ/tslag. Compared with the traditional physical recycling method producing steam, the exergy and thermal efficiencies of the integrated system were improved significantly. Meanwhile, approximately 182.0 m3/tslag syngas was produced by coal gasification. The BF slag waste heat will be used integrally and efficiently by the integrated system. The results provide the theoretical reference for recycling and using the BF slag waste heat.

  14. Preparation of glass-forming materials from granulated blast furnace slag

    Science.gov (United States)

    Alonso, M.; Sáinz, E.; Lopez, F. A.

    1996-10-01

    Glass precursor materials, to be used for the vitrification of hazardous wastes, have been prepared from blast furnace slag powder through a sol-gel route. The slag is initially reacted with a mixture of alcohol (ethanol or methanol) and mineral acid (HNO3 or H2SO4) to give a sol principally consisting of Si, Ca, Al, and Mg alkoxides. Gelation is carried out with variable amounts of either ammonia or water. The gelation rate can be made as fast as desired by adding excess hydrolizing agent or else by distilling the excess alcohol out of the alkoxide solution. The resulting gel is first dried at low temperature and ground. The powder thus obtained is then heat treated at several temperatures. The intermediate and final materials are characterized by thermal analysis, infrared (IR) spectroscopy, X-ray diffraction, scanning electron microscopy (SEM), and chemical analysis. From the results, the operating conditions yielding a variety of glass precursors differing in their composition are established. The method, in comparison with direct vitrification of slag, presents a number of advantages: (1) the glass precursor obtained devitrifies at higher temperatures; (2) it enables the adjustment, to a certain extent, of the chemical composition of the glass precursor; and (3) it permits recovering marketable materials at different stages of the process.

  15. Performance and Behaviour of Ground Granulated Blast Furnace Slag Imparted to Geopolymer Concrete Structural Elements and Analyzed with ANSYS

    Directory of Open Access Journals (Sweden)

    Maria Rajesh Antonyamaladhas

    2016-01-01

    Full Text Available This paper deals with the behaviour of geopolymer concrete using ground granulated blast furnace slag and steel fibre to compare with M40 grade cement concrete. The cast GPC specimens were placed in a hot curing chamber at 60∘C temperature for 24 hours and tested after 1, 7, 14, and 28 days of ambient curing to find the strength and durability of hardened concrete. The optimum value of compressive strength was attained at 12 Molarities. Fly ash was replaced by GGBS in GPC with different proportions such as 0% to 60% at 5% interval; the optimum strength value was obtained on 40% replacement. From the test results, the compressive, split-tensile, and flexural strength of GPC specimens were 20%, 43%, and 53% higher than those of the control specimens. Based on the optimum strength mix proportion, the structural elements were cast to investigate the stress-strain relations. The GPC beam and L-section showed 33% and 16% higher value. From the results of acid and sulphate resistance tests, it was found that the strength and weight ratio of GPC were higher than the control specimens. From the simulations, it was found that the experimental test results were approximately equal to the ANSYS.

  16. The setting time of a clay-slag geopolymer matrix: the influence of blast-furnace-slag addition and the mixing method

    Czech Academy of Sciences Publication Activity Database

    Perná, Ivana; Hanzlíček, Tomáš

    112, Part 1, JAN 20 (2016), s. 1150-1155 ISSN 0959-6526 Institutional support: RVO:67985891 Keywords : blast-furnace slag * geopolymer * setting time * mixing method * solidification * recycling Subject RIV: DM - Solid Waste and Recycling Impact factor: 5.715, year: 2016

  17. Blast furnace dust and phosphorous slag, new materials for use in road engineering

    Science.gov (United States)

    Ochoa Díaz, R.

    2017-12-01

    This article proposes an alternative to the use of phosphorus slag and blast furnace dust, by-products of the steel industry, due to the negative environmental impact caused by its accumulation. Taking into account the above, the pertinence of the use of these by-products in asphalt mixtures for the construction of roads is studied. In this way, the origin and its properties are presented, as well as their physical and chemical characteristics. Once the tests have been carried out, it is determined that these by-products have adequate characteristics for their use since they do not present toxicity problems. Following this, the design of the mixtures is carried out to determine the mechanical and dynamic properties and thus determine the proportion to be replaced with the conventional materials. Taking into account the results it is concluded that its use is feasible since the mixture with these by-products presents acceptable resilient modulus parameters and improvement in some verification parameters.

  18. Alkaline-sulphate activation processes of a Spanish blast furnace slag

    Directory of Open Access Journals (Sweden)

    Fernández Jiménez, A.

    1996-03-01

    Full Text Available Alkaline-sulphate activation processes of a Spanish granulated blast furnace slag (Avilés, Ensidesa have been studied. Activator solutions used were: deionized water (as reference solution, Ca(OH2 (3,5∙10-3N, NaOH (1N, Na2CO3 (2N, CaSO4∙2H2O (3,0∙10-3N at 25ºC. The influence of the nature of alkaline or sulphate solution cation on slag activation process was verified. Sodium solutions decrease the induction period while calcium solutions increase it. Slag reaction degree was also determined, likewise the nature of the different reaction products formed as a function of the activator solution nature.

    Se han estudiado los procesos de activación alcalinosulfáticos de una escoria granulada de alto horno española (Avilés, Ensidesa. Las disoluciones activantes utilizadas fueron: H2O desionizada (como disolución de referencia, Ca(OH2 (3,5∙10-3N, NaOH (1N, Na2CO3 (2N, CaSO4∙2H2O (3,0∙10-3N a 25ºC. Se ha comprobado la influencia de la naturaleza del catión de la disolución alcalina o sulfática sobre el proceso de activación de la escoria. Las disoluciones sódicas disminuyen el período de inducción, mientras que las disoluciones cálcicas lo incrementan. También se determinó el grado de reacción de la escoria, así como la naturaleza de los distintos productos de reacción formados, en función de la naturaleza de la disolución activante.

  19. Properties of mortars made by uncalcined FGD gypsum-fly ash-ground granulated blast furnace slag composite binder.

    Science.gov (United States)

    Zhong, Shiyun; Ni, Kun; Li, Jinmei

    2012-07-01

    A series of novel mortars were developed from composite binder of uncalcined FGD gypsum, fly ash (FA) and ground granulated blast furnace slag (GGBFS) for the good utilization of flue gas desulphurization (FGD) gypsum. At a fixed ratio (20%) of GGBFS to the composite binder, keeping consistency of the mortar between 9.5 and 10.0 cm, the properties of the composite mortar were studied. The results show that higher water/binder (W/B) is required to keep the consistency when increasing the percentage of FGD gypsum. No obvious influences of the W/B and content of FGD gypsum on the bleeding of paste were observed which keeps lower than 2% under all experimental conditions tried. The highest compressive and flexural strengths (ratio is 20% FGD gypsum, 20% GGBFS and 60% FA) are 22.6 and 4.3 MPa at 28 days, respectively. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) results indicate that massive ettringite crystals and C-S-H gels exist in the hydration products. At 90 days the mortars with FGD gypsum is dramatically smaller drying shrinkage (563-938 micro strain) than that without FGD gypsum (about 2250 micro strain). The release of the SO(4)(2-) from the mortar was analyzed, indicating that the dissolution of sulfate increases with FGD gypsum. The concentration of SO(4)(2-) releasing from the mortar with 10% FGD gypsum is almost equal to that obtained from the mortar without FGD gypsum. The release of SO(4)(2-) from the mortar with 20% FGD gypsum is 9200 mg·m(-2), which is lower than that from the mortar with 95% cement clinker and 5% FGD gypsum. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Effect of High-Temperature Curing Methods on the Compressive Strength Development of Concrete Containing High Volumes of Ground Granulated Blast-Furnace Slag

    Directory of Open Access Journals (Sweden)

    Wonsuk Jung

    2017-01-01

    Full Text Available This paper investigates the effect of the high-temperature curing methods on the compressive strength of concrete containing high volumes of ground granulated blast-furnace slag (GGBS. GGBS was used to replace Portland cement at a replacement ratio of 60% by binder mass. The high-temperature curing parameters used in this study were the delay period, temperature rise, peak temperature (PT, peak period, and temperature down. Test results demonstrate that the compressive strength of the samples with PTs of 65°C and 75°C was about 88% higher than that of the samples with a PT of 55°C after 1 day. According to this investigation, there might be optimum high-temperature curing conditions for preparing a concrete containing high volumes of GGBS, and incorporating GGBS into precast concrete mixes can be a very effective tool in increasing the applicability of this by-product.

  1. Effect of incorporation of fly ash and granulated blast furnace in the electrochemical behavior of concretes of commercial cement; Efecto de la incorporacion de ceniza volante y escoria de horno alto en el comportamiento electroquimico de concretos de cemento comercial

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez-Junco, O. J.; Pineda-Triana, Y.; Vera-Lopez, E.

    2015-07-01

    This paper presents the findings of the research properties evaluation pastes of commercial cement (CPC), mixed with fly ash (FA) and granulated blast furnace slag (GBFS). Initially, the sample of 30 combinations were evaluated in terms of compressive strength to establish the optimal proportions from raw material. After that, four optimized blends were characterized during the setting and hardening process. Electrochemical tests were performed on concrete cylinders samples prepared with cementitious materials and a structural steel rod placed in the center of the specimen. With the objective to evaluate the performance before corrosion, thermodynamic and kinetic aspects were taken into consideration. The findings showed that commercial cements blended with fly ash and blast furnace slag as the ones used in this research presents a decreased behavior in mechanical and corrosion strength regarding to CPC. (Author)

  2. The Use of Blast Furnace Slag for Removal of Phosphorus from Wastewater in Sweden—A Review

    Directory of Open Access Journals (Sweden)

    Lena Johansson Westholm

    2010-10-01

    Full Text Available Research on Phosphorus (P removal capacity by blast furnace slags (BFS has been undertaken in Sweden for the last decade. Both laboratory experiments and field trials have been carried out. While laboratory investigations revealed that BFS has a high P-sorption capacity (95–100%, P removal in field trials was much lower, ranging from 40 to 53%. In addition, a number of problems have been observed in BFS field testing including clogging, sulfuric odor and environmental (regulatory concerns about possible leaching of heavy metals from the slag. In spite of these problems, and questioning by the environmental regulatory authorities, research continues to provide evidence that BFS can be regarded as a suitable filter media, and attempts have also been undertaken in order to further improve the P-removal capacity of this adsorbing material.

  3. Influence of B2O3 and Basicity on Viscosity and Structure of Medium Titanium Bearing Blast Furnace Slag

    Directory of Open Access Journals (Sweden)

    Lingtao Bian

    2016-01-01

    Full Text Available The effects of B2O3 and basicity (CaO/SiO2 on the viscous behavior and structure of medium titanium bearing blast furnace slag (MTBBFS were investigated. High temperature viscosimeter was applied to measure the viscosities of CaO-SiO2-MgO-TiO2-Al2O3-B2O3 slag system and X-ray diffraction (XRD, NBO/T ratio, and structure parameter Q were employed to analyze its network structure. The results showed that the viscosity decreased and break point temperature increased with increasing basicity to 1.20. However B2O3 addition gave rise to a decrease in slag viscosity and break point temperature inspite of basicity. The more B2O3 content leads to the more pronounced variation, especially for the slag with larger basicity. The conventional NBO/T formula was revised to predict the structure variation of relatively complicated medium Ti bearing slag based on the work of Yanhong Gao and other researchers. The increase of B2O3 content in slag made parameter Q turn from Q2 to Q1, suggesting that network structure became simpler. It was also noticed that the addition of B2O3 could suppress the formation of perovskite.

  4. Thermal treatment of simulant plutonium contaminated materials from the Sellafield site by vitrification in a blast-furnace slag

    Energy Technology Data Exchange (ETDEWEB)

    Hyatt, N.C., E-mail: n.c.hyatt@sheffield.ac.uk [Department of Materials Science and Engineering, The University of Sheffield, Mappin Street, Sheffield S1 3JD (United Kingdom); Schwarz, R.R.; Bingham, P.A.; Stennett, M.C.; Corkhill, C.L.; Heath, P.G.; Hand, R.J. [Department of Materials Science and Engineering, The University of Sheffield, Mappin Street, Sheffield S1 3JD (United Kingdom); James, M.; Pearson, A. [Sellafield Ltd., Sellafield, Seascale, Cumbria CA20 1PG (United Kingdom); Morgan, S. [Sellafield Ltd., Hinton House, Risley, Warrington WA3 6GR (United Kingdom)

    2014-01-15

    Graphical abstract: Storage of 200 L drums of PCM waste at the Sellafield site, UK. Abstract: Four waste simulants, representative of Plutonium Contaminated Materials (PCMs) at the Sellafield site, were vitrified through additions of Ground Granulated Blast-furnace Slag (GGBS). Ce (as a Pu surrogate) was effectively partitioned into the slag product, enriched in an amorphous CaO–Fe{sub 2}O{sub 3}–Al{sub 2}O{sub 3}–SiO{sub 2} phase when other crystalline phases were also present. Ce L{sub 3} edge XANES data demonstrated Ce to be present as trivalent species in the slag fraction, irrespective of the waste type. Estimated volume reductions of ca. 80–95% were demonstrated, against a baseline of uncompacted 200 L PCM waste drums. The dissolution behaviour of PCM slag wasteforms was investigated at 50 °C in saturated Ca(OH){sub 2} solution under N{sub 2} atmosphere, to simulate the hyperalkaline anoxic environment of a cementitious UK Geological Disposal Facility for Intermediate Level Waste (ILW). These experiments demonstrated the performance of the slag wasteforms to be comparable to that of other vitrified ILW materials considered potentially suitable for geological disposal.

  5. Properties of mortars made by uncalcined FGD gypsum-fly ash-ground granulated blast furnace slag composite binder

    International Nuclear Information System (INIS)

    Zhong Shiyun; Ni Kun; Li Jinmei

    2012-01-01

    Highlights: ► The mortar with uncalcined FGD gypsum has suitable workability. ► The strength of mortar with uncalcined FGD gypsum is higher than that of mortar without uncalcined FGD gypsum. ► The dry shrinkage of mortar with uncalcined FGD gypsum is lower than that of mortar without uncalcined FGD gypsum. ► The leaching of sulfate ion of mortar is studied. - Abstract: A series of novel mortars were developed from composite binder of uncalcined FGD gypsum, fly ash (FA) and ground granulated blast furnace slag (GGBFS) for the good utilization of flue gas desulphurization (FGD) gypsum. At a fixed ratio (20%) of GGBFS to the composite binder, keeping consistency of the mortar between 9.5 and 10.0 cm, the properties of the composite mortar were studied. The results show that higher water/binder (W/B) is required to keep the consistency when increasing the percentage of FGD gypsum. No obvious influences of the W/B and content of FGD gypsum on the bleeding of paste were observed which keeps lower than 2% under all experimental conditions tried. The highest compressive and flexural strengths (ratio is 20% FGD gypsum, 20% GGBFS and 60% FA) are 22.6 and 4.3 MPa at 28 days, respectively. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) results indicate that massive ettringite crystals and C–S–H gels exist in the hydration products. At 90 days the mortars with FGD gypsum is dramatically smaller drying shrinkage (563–938 micro strain) than that without FGD gypsum (about 2250 micro strain). The release of the SO 4 2- from the mortar was analyzed, indicating that the dissolution of sulfate increases with FGD gypsum. The concentration of SO 4 2- releasing from the mortar with 10% FGD gypsum is almost equal to that obtained from the mortar without FGD gypsum. The release of SO 4 2- from the mortar with 20% FGD gypsum is 9200 mg·m −2 , which is lower than that from the mortar with 95% cement clinker and 5% FGD gypsum.

  6. The Environmental Impact and Cost Analysis of Concrete Mixing Blast Furnace Slag Containing Titanium Gypsum and Sludge in South Korea

    Directory of Open Access Journals (Sweden)

    Tae Hyoung Kim

    2016-05-01

    Full Text Available This study assessed the environmental effects and cost of the Industrial Waste addictive Blast Furnace Slag (W-BFS using Life Cycle Assessment (LCA and compared it to general BFS. The environmental impacts of W-BFS were as follows: 1.12 × 10−1 kg-CO2 eq/kg, 3.18 × 10−5 kg-Ethylene eq/kg, 4.79 × 10−4 kg-SO2 eq/kg, 7.15 × 10−4 kg-PO43− eq/kg, 7.15 × 10−4 kg-CFC11 eq/kg and 3.94 × 10−3 kg-Antimony eq/kg. Among the environmental impact category, GWP and AP were 9.28 × 10−2 kg-CO2 eq/kg and 3.33 × 10−4 kg-SO2 eq/kg at a raw material stage, accounting for 80% and 70% of total environmental impact respectively. In EP, POCP and ADP, in addition, raw material stage accounted for a great portion in total environmental impact because of “W” among input materials. In ODP, however, compared to the environmental impact of raw materials, oil, which was used in transporting BFS to the W-BFS manufacturing factory, was more influential. In terms of GWP, POCP and ODP, W-BFS was higher than general BFS. In terms of AP, EP and ADP, in contrast, the former was lower than the latter. In terms of cost, W-BFS (41.7 US$/ton was lower than general BFS by about 17% because of the use of waste additives comprised of industrial wastes instead of natural gypsum ,which has been commonly used in general BFS. In terms of GWP and POCP, the W-BFS mixed (30% concrete was lower than plain concrete by 25%. In terms of AP and EP, the former was lower than the latter by 30%. In terms of ADP, furthermore, W-BFS mixed (30% concrete was lower than plain concrete by 11%. In aggregate-related ODP, however, almost no change was found. In terms of cost, when W-BFS was added by 10% and 30%, it was able to reduce cost by 3% and 7% respectively, compared to plain concrete. Compared to BFS-mixed concrete as well, cost could be saved by 1% additionally because W-BFS (US$41.7/ton is lower than common cement (US$100.3/ton by about 60% in terms of production costs.

  7. Study on the durability of concrete using granulated blast furnace slag as fine aggregate

    Science.gov (United States)

    Shi, Dongsheng; Liu, Qiang; Xue, Xinxin; He, Peiyuan

    2018-03-01

    In order to assessing the durability of concrete using granulated blastfurnace slag (GBS) as fine aggregate and compare it with natural river sand concrete, three different size of specimen were produced by using the same mix proportion with 3 different water cement ratios and 3 replacement ratios, and using it to measure the three aspects on the durability of concrete including freeze-thaw performance, dry-shrinkage performance and anti-chloride-permeability performance. In this paper. The test results show that using GBS as fine aggregate can slightly improve anti-chloride-permeability performance and dry-shrinkage performance of concrete in the condition of low water cement ratio, on the other hand, using GBS or natural river sand as fine aggregate has almost similar durability of concrete.

  8. Carbonation Characteristics of Alkali-Activated Blast-Furnace Slag Mortar

    Directory of Open Access Journals (Sweden)

    Keum-Il Song

    2014-01-01

    Full Text Available Alkali-activated ground granulated blast-slag (AAS is the most obvious alternative material for ordinary Portland cement (OPC. However, to use it as a structural material requires the assessment and verification of its durability. The most important factor for a durability evaluation is the degree of carbonation resistance, and AAS is known to show lower performance than OPC. A series of experiments was conducted with a view to investigate the carbonation characteristics of AAS binder. As a consequence, it was found that the major hydration product of AAS was calcium silicate hydrate (CSH, with almost no portlandite, unlike the products of OPC. After carbonation, the CSH of AAS turned into amorphous silica gel which was most likely why the compressive strength of AAS became weaker after carbonation. An increase of the activator dosage leads AAS to react more quickly and produce more CSH, increasing the compaction, compressive strength, and carbonation resistance of the microstructure.

  9. The characterisation, improvement and modelling aspects of Frost Salt Scaling of Cement-Based Materials with a High Slag Content

    NARCIS (Netherlands)

    Copuroglu, O.

    2006-01-01

    Blast furnace slag cement concrete is used extensively in a number of countries. In comparison with OPC, it is particularly well known for its excellent performance in marine environments. One dis-advantage of slag cement is its vulnerability to scaling under the combined load of freezing-thawing

  10. Recycling ground granulated blast furnace slag as cold bonded artificial aggregate partially used in self-compacting concrete.

    Science.gov (United States)

    Gesoğlu, Mehmet; Güneyisi, Erhan; Mahmood, Swara Fuad; Öz, Hatice Öznur; Mermerdaş, Kasım

    2012-10-15

    Ground granulated blast furnace slag (GGBFS), a by-product from iron industry, was recycled as artificial coarse aggregate through cold bonding pelletization process. The artificial slag aggregates (ASA) replaced partially the natural coarse aggregates in production of self-compacting concrete (SCC). Moreover, as being one of the most widely used mineral admixtures in concrete industry, fly ash (FA) was incorporated as a part of total binder content to impart desired fluidity to SCCs. A total of six concrete mixtures having various ASA replacement levels (0%, 20%, 40%, 60%, and 100%) were designed with a water-to-binder (w/b) ratio of 0.32. Fresh properties of self-compacting concretes (SCC) were observed through slump flow time, flow diameter, V-funnel flow time, and L-box filling height ratio. Compressive strength of hardened SCCs was also determined at 28 days of curing. It was observed that increasing the replacement level of ASA resulted in decrease in the amount of superplasticizer to achieve a constant slump flow diameter. Moreover, passing ability and viscosity of SCC's enhanced with increasing the amount of ASA in the concrete. The maximum compressive strength was achieved for the SCC having 60% ASA replacement. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. Effect of γ-irradiation on the electrical conductivity of some soda lime silicate glass containing blast furnace slag

    International Nuclear Information System (INIS)

    Elalaily, N.A.; Khalil, Magda M.I.; Ahmed, L.S.

    2007-01-01

    The effect of electric field strength on conduction in soda lime silicate glass doped with blast furnace slag with different concentration was studied and the value of jump distance was calculated. The structure and the mixed anion effect in the conductivity have been examined by measuring the electrical conductivity of glass samples at temperature ranging between 20 and 250 deg. C. The results showed that the electrical conductivity of the examined glasses are divided into three ranges depending on the temperature range. The first is from room temperature to about 49.5 deg. C, the second is at a temperature range of 60.3-104 deg. C where the glass shows a decrease in its conductivity with the increase in temperature. This was followed by another increase in the electrical conductivity with the increase in temperature. The results also showed that the glass becomes more insulating as the slag content increased. The effect of irradiation was also studied by exposing glass samples to two different irradiation doses. It can be noticed that irradiation causes an increase in the electrical conductivity, especially at high temperature. The results were discussed and correlated according to the molecular structure of the prepared glass

  12. Simultaneous removal of Ni(II), As(III), and Sb(III) from spiked mine effluent with metakaolin and blast-furnace-slag geopolymers.

    Science.gov (United States)

    Luukkonen, Tero; Runtti, Hanna; Niskanen, Mikko; Tolonen, Emma-Tuulia; Sarkkinen, Minna; Kemppainen, Kimmo; Rämö, Jaakko; Lassi, Ulla

    2016-01-15

    The mining industry is a major contributor of various toxic metals and metalloids to the aquatic environment. Efficient and economical water treatment methods are therefore of paramount importance. The application of natural or low-cost sorbents has attracted a great deal of interest due to the simplicity of its process and its potential effectiveness. Geopolymers represent an emerging group of sorbents. In this study, blast-furnace-slag and metakaolin geopolymers and their raw materials were tested for simultaneous removal of Ni(II), As(III) and Sb(III) from spiked mine effluent. Blast-furnace-slag geopolymer proved to be the most efficient of the studied materials: the experimental maximum sorption capacities for Ni, As and, Sb were 3.74 mg/g, 0.52 mg/g, and 0.34 mg/g, respectively. Although the capacities were relatively low due to the difficult water matrix, 90-100% removal of Ni, As, and Sb was achieved when the dose of sorbent was increased appropriately. Removal kinetics fitted well with the pseudo-second-order model. Our results indicate that geopolymer technology could offer a simple and effective way to turn blast-furnace slag to an effective sorbent with a specific utilization prospect in the mining industry. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Influence of seawater mixing and curing on strength characteristics and porosity of ground granulated blast-furnace slag concrete

    Science.gov (United States)

    Adiwijaya; Hamada, H.; Sagawa, Y.; Yamamoto, D.

    2017-11-01

    Generally, in the concrete industry, several billion tons of fresh water are annually used for mixing water, curing water and cleaning water. Nevertheless, the utilization of seawater in the concrete industry is prohibited, because it increases the risk of corrosion of steel bars in concrete. This study presents strength characteristics and porosity of seawater mixed concrete and tap water mixed concrete incorporating Ground Granulated Blast-Furnace Slag (GGBS) with water-binder ratio (W/B) of 40%, 50% and 60%. The influence of seawater mixing, GGBS and curing conditions such as tap water curing (TC), seawater curing (SC) and air curing (AC) on the strength and porosity of concrete were evaluated. Based on investigation result, it was shown that there is no significant influence of seawater mixing in improving strength of GGBS concrete up to 365 days in TC and SC. Effectiveness of seawater-mixing on strength enhancement of GGBS concrete is larger in air curing than in water curing. Porosity of seawater-mixed concrete is decreased compared to tap water-mixed concrete in all curing conditions.

  14. High calcium fly ash geopolymer stabilized lateritic soil and granulated blast furnace slag blends as a pavement base material.

    Science.gov (United States)

    Phummiphan, Itthikorn; Horpibulsuk, Suksun; Rachan, Runglawan; Arulrajah, Arul; Shen, Shui-Long; Chindaprasirt, Prinya

    2018-01-05

    Granulated Blast Furnace Slag (GBFS) was used as a replacement material in marginal lateritic soil (LS) while class C Fly Ash (FA) was used as a precursor for the geopolymerization process to develop a low-carbon pavement base material at ambient temperature. Unconfined Compression Strength (UCS) tests were performed to investigate the strength development of geopolymer stabilized LS/GBFS blends. Scanning Electron Microscopy and X-ray Diffraction analysis were undertaken to examine the role of the various influencing factors on UCS development. The influencing factors studied included GBFS content, Na 2 SiO 3 :NaOH ratio (NS:NH) and curing time. The 7-day soaked UCS of FA geopolymer stabilized LS/GBFS blends at various NS:NH ratios tested was found to satisfy the specifications of the Thailand national road authorities. The GBFS replacement was found to be insignificant for the improvement of the UCS of FA geopolymer stabilized LS/GBFS blends at low NS:NH ratio of 50:50. Microstructural analysis indicated the coexistence of Calcium Silicate Hydrate (CSH) and Sodium Alumino Silicate Hydrate products in FA geopolymer stabilized LS/GBFS blends. This research enables GBFS, which is traditionally considered as a waste material, to be used as a replacement and partially reactive material in FA geopolymer pavement applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Reductive solidification/stabilization of chromate in municipal solid waste incineration fly ash by ascorbic acid and blast furnace slag.

    Science.gov (United States)

    Zhou, Xian; Zhou, Min; Wu, Xian; Han, Yi; Geng, Junjun; Wang, Teng; Wan, Sha; Hou, Haobo

    2017-09-01

    Fly ash is a hazardous byproduct of municipal solid waste incineration (MSWI). Cementitious material that is based on ground-granulated blast furnace slag (GGBFS) has been tested and proposed as a binder to stabilize Pb, Cd, and Zn in MSWI fly ash (FA). Cr, however, still easily leaches from MSWI FA. Different reagents, such as ascorbic acid (VC), NaAlO 2 , and trisodium salt nonahydrate, were investigated as potential Cr stabilizers. The results of the toxicity characteristic leaching procedure (TCLP) showed that VC significantly improved the stabilization of Cr via the reduction of Cr(VI) to Cr(III). VC, however, could interfere with the hydration process. Most available Cr was transformed into stable Cr forms at the optimum VC content of 2 wt%. Cr leaching was strongly pH dependent and could be represented by a quintic polynomial model. The results of X-ray diffraction and scanning electron microscopy-energy dispersive analysis revealed that hollow spheres in raw FA were partially filled with hydration products, resulting in the dense and homogeneous microstructure of the solidified samples. The crystal structures of C-S-H and ettringite retained Zn and Cr ions. In summary, GGBFS-based cementitious material with the low addition of 2 wt% VC effectively immobilizes Cr-bearing MSWI FA. Copyright © 2017. Published by Elsevier Ltd.

  16. The Characterization of Fixation of Ba, Pb, and Cu in Alkali-Activated Fly Ash/Blast Furnace Slag Matrix

    Directory of Open Access Journals (Sweden)

    Jan Koplík

    2016-06-01

    Full Text Available The fixation of heavy metals (Ba, Cu, Pb in an alkali-activated matrix was investigated. The matrix consisted of fly ash and blast furnace slag (BFS. The mixture of NaOH and Na-silicate was used as alkaline activator. Three analytical techniques were used to describe the fixation of heavy metals—X-ray photoelectron spectroscopy (XPS, scanning electron microscopy (SEM equipped with energy dispersive X-ray spectroscopy (EDS, and X-ray powder diffraction (XRD. All heavy metals formed insoluble salts after alkaline activation. Ba was fixed as BaSO4, and only this product was crystalline. EDS mapping showed that Ba was cumulated in some regions and formed clusters. Pb was present in the form of Pb(OH2 and was dispersed throughout the matrix on the edges of BFS grains. Cu was fixed as Cu(OH2 and also was cumulated in some regions and formed clusters. Cu was present in two different chemical states; apart from Cu(OH2, a Cu–O bond was also identified.

  17. Influence of the soluble fraction of blast furnace slag on the growth of some algae

    Energy Technology Data Exchange (ETDEWEB)

    Tokuda, H.

    1977-01-01

    The sea water-soluble fraction of the pulverized slag was prepared in anaerobic condition, and mixed with a basal medium in various ratios for preparation of a culture medium, on which the growth of a diatom, Skeletonema costatum, was suppressed. The inhibitory effect of the soluble fraction to this alga was reduced to a certain degree when the culture medium had been aerated with nitrogen preceding inoculation. The growth of Skel. costatum was also inhibited on the basal medium containing the untreated slag powder in various amounts, while it was stimulated when the slag powder was washed for several days before addition to the basal medium. The soluble fraction of the slag affected unfavorably the growth of a laver, Porphyra yezoensis, also. A diatom, Nitzschia closterium, was able to grow closely adhering to the slag powder. The inhibitory effect of the soluble fraction of the slag to algae seems to be caused largely by potassium or sodium sulfide, and slightly by sulfur oxides and some heavy metals dissolved in trace amounts.

  18. Repulsion forces of superplasticizers on ground granulated blast furnace slag in alkaline media, from AFM measurements to rheological properties

    Directory of Open Access Journals (Sweden)

    Palacios, M.

    2012-12-01

    Full Text Available The electrostatic and steric repulsion induced by different superplasticizers on ground granulated blast furnace slag in alkaline media have been studied. The superplasticizers were sulfonated naphthalene, sulfonated melamine, vinyl copolymer, and polycarboxylate- based admixtures. With these superplasticizers the slag suspensions had negative zeta potentials, ranging from -3 to -10 mV. For the first time the adsorbed layer thicknesses for superplasticizers on slag using colloidal probe atomic force microscopy has been measured. To model the interparticle force interactions an effective Hamaker constant was computed from dielectric properties measured on a dense slag sample produced by spark plasma sintering. The obtained results conclude that the dispersion mechanism for all the superplasticizers studied in the present work is mainly dominated by the steric repulsion. Results were then used in a yield stress model, YODEL, to predict the yield stress with and without the superplasticizers. Predictions of the yield stress agreed well with experimental results.

    En este trabajo se ha estudiado la repulsión electrostática y estérica inducida por diferentes aditivos superplastificantes en sistemas de escoria de horno alto en medios alcalinos. Se han estudiado aditivos superplastificantes basados en naftaleno, melamina, copolímeros vinílicos y basados en policarboxilato. Estos aditivos inducen en la escoria un potencial zeta negativo, entre -3 y -10 mV. Por primera vez, se ha determinado el grosor de la capa de aditivo adsorbido sobre la escoria mediante microscopía de fuerzas atómicas (AFM. Para modelizar las fuerzas de interacción entre partículas, se ha determinado la constante efectiva de Hamaker de la escoria a partir de las propiedades dieléctricas de una muestra de escoria obtenida mediante sinterización spark plasma sintering. Los resultados obtenidos concluyen que el mecanismo de dispersión de los superplastificantes

  19. Two-stage high temperature sludge gasification using the waste heat from hot blast furnace slags.

    Science.gov (United States)

    Sun, Yongqi; Zhang, Zuotai; Liu, Lili; Wang, Xidong

    2015-12-01

    Nowadays, disposal of sewage sludge from wastewater treatment plants and recovery of waste heat from steel industry, become two important environmental issues and to integrate these two problems, a two-stage high temperature sludge gasification approach was investigated using the waste heat in hot slags herein. The whole process was divided into two stages, i.e., the low temperature sludge pyrolysis at ⩽ 900°C in argon agent and the high temperature char gasification at ⩾ 900°C in CO2 agent, during which the heat required was supplied by hot slags in different temperature ranges. Both the thermodynamic and kinetic mechanisms were identified and it was indicated that an Avrami-Erofeev model could best interpret the stage of char gasification. Furthermore, a schematic concept of this strategy was portrayed, based on which the potential CO yield and CO2 emission reduction achieved in China could be ∼1.92∗10(9)m(3) and 1.93∗10(6)t, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Rice husk ash as a source of silica in alkali-activated fly ash and granulated blast furnace slag systems

    Directory of Open Access Journals (Sweden)

    Mejía, J. M.

    2013-09-01

    Full Text Available This study assesses the viability of using an agro-industrial by-product, rice husk ash (RHA from a Colombian rice company’s combustion facility, as a total replacement for the commercial sodium silicate ordinarily used in alkaliactivated binders. Fly ash (FA, granulated blast furnace slag (GBFS and binary 50FA:50GBFS blended pastes were activated with a mix of sodium hydroxide and either sodium silicate or one of two types of RHA. The pastes were characterised for strength, mineralogy and microstructure. The findings showed that the agro-industrial by-product can be used to yield alkali-activated materials with 7-day mechanical strengths on the order of 42 MPa. The study confirmed that both amorphous silica and part of the crystalline silica present in RHA participate in the alkaline activation process, providing the alkalinity is suitably adjusted.Este estudio evalúa la viabilidad de utilizar un subproducto agroindustrial, la ceniza de cascarilla de arroz (RHA proveniente de un equipo combustor de una empresa Arrocera en Colombia, como reemplazo total de la sílice aportada por el silicato de sodio comercial en sistemas cementicios activados alcalinamente. Se prepararon pastas de ceniza volante (FA, de escoria de alto horno (GBFS y un sistema binario 50FA:50GBFS, que fueron activadas por una mezcla de silicato de sodio e hidróxido de sodio, y por dos tipos de RHA. Las mezclas se caracterizaron mecánica, mineralógica y microestructuralmente. Los resultados demuestran que es posible obtener materiales activados alcalinamente con resistencias mecánicas del orden de 42 MPa, a 7 días de curado, utilizando el subproducto agroindustrial. Este estudio corrobora que tanto la sílice amorfa como parte de la sílice cristalina presente en RHA tienen la posibilidad de participar en el proceso de activación alcalina, siempre y cuando las condiciones de alcalinidad estén adecuadamente ajustadas.

  1. Influence of the activator concentration on the kinetics of the alkaline activation process of a blast furnace slag

    Directory of Open Access Journals (Sweden)

    Fernández-Jiménez, A.

    1997-06-01

    Full Text Available The influence of activator solution concentration on hydration kinetics of an alkaline activated blast furnace slag has been studied. The alkaline activator used was a mix of waterglass (Na2SiO3∙nH2O and NaOH solution (of variable concentration. Final activator concentrations were 3,4 and 5 % Na2O wt. with respect to the slag total weight. Degree of reaction (α was determined from hydration heat values obtained through isothermal conduction calorimetry. From the results obtained it is deduced that a treshold value of 4 % Na2O wt. exists. For those concentrations and at test temperatures (except for 25ºC and 3 % Na2O wt., the mechanism controlling hydration reaction for a values higher than 0.5, is a diffusion process. This process is described by .Jander equation [D3=(1-(1-α1/32=(k/r2t=0,0426(t/t0,5]. The activation energy obtained for that process is of approximately 50-58 Kj/mol.

    Se ha estudiado la influencia de la concentración de la disolución activante en la cinética de hidratación de una escoria granulada de alto horno, activada alcalinamente a distintas temperaturas. El activador alcalino utilizado fue una mezcla de water glass (Na2SiO3∙nH2O con una disolución de NaOH (de concentración variable. Las concentraciones finales del activador alcalino fueron: 3, 4 y 5 % en peso de Na2O respecto a la masa total de escoria. El grado de reacción (α se determinó a partir de valores de calor de hidratación obtenidos por calorimetría de conducción isotérmica. De los resultados obtenidos se deduce que existe un valor umbral de concentraciones en torno al 4 % en peso de Na2O. También para dichas concentraciones y a las temperaturas de ensayo (excepto a 25ºC con un 3 % en peso de Na2O, el mecanismo que controla la reacción de hidrataci

  2. Improving the properties of geopolymer containing oil-contaminated clay, metakaolin, and blast furnace slag by applying nano-SiO2.

    Science.gov (United States)

    Luo, Huan-Lin; Lin, Deng-Fong; Chen, Shih-Chieh

    2017-07-01

    In this study, geopolymer specimens based on calcined oil-contaminated clays (OCCs), metakaolin replacements of OCCs, and blast furnace slag were manufactured by the addition of nano-SiO 2 to improve their properties. The effects of adding 0, 1, 2, or 3% nano-SiO 2 on the properties and microstructures of the geopolymer specimens were determined using compressive strength tests, flow tests, setting time tests, scanning electron microscopy (SEM), and silicon nuclear magnetic resonance spectroscopy (Si-NMR). The results showed that the setting time and flowability of the geopolymer specimens decreased and the compressive strength increased as the amount of nano-SiO 2 increased. These results were supported by the SEM and Si-NMR assays. This study suggests that the addition of nano-SiO 2 was beneficial and improved the properties of the geopolymer specimens containing calcined OCC.

  3. Electrorheological effect of Ti-bearing blast furnace slag with different TiC contents at 1500°C

    Science.gov (United States)

    Yue, Hong-rui; Jiang, Tao; Zhang, Qiao-yi; Duan, Pei-ning; Xue, Xiang-xin

    2017-07-01

    The electrorheological properties of CaO-SiO2-Al2O3-MgO-TiO2-TiC slags were investigated to enhance understanding of the effect of TiC addition on the viscosity, yield stress, and fluid pattern of Ti-bearing slags in a direct-current electric field. The viscosities and shear stresses of 4wt% and 8wt% TiC slags were found to increase substantially with increasing electric field intensity, whereas virtually no rheological changes were observed in the 0wt% TiC slag. The Herschel-Bulkley model was applied to demonstrate that the fluid pattern of the 4wt% TiC slag was converted from that of a Newtonian fluid to that of a Bingham fluid in response to the applied electric field; and the static yield stress increased linearly with the square of the electric field intensity.

  4. Estimation of Corrosion-Free Life for Concrete Containing Ground Granulated Blast-Furnace Slag under a Chloride-Bearing Environment

    Directory of Open Access Journals (Sweden)

    Sung In Hong

    2017-01-01

    Full Text Available The rate of chloride transport by diffusion in concrete containing ground granulated blast-furnace slag (GGBS was mathematically estimated to predict the corrosion-free service life of concrete structures exposed to seawater environment. As a factor to corrosiveness of steel embedment, replacement ratio of GGBS was selected, accounting for 25 and 50% to total binder. As a result, it was found that an increase in the GGBS content resulted in an increase in the chloride binding capacity, which would give rise to a lower chloride diffusion rate, thereby reducing the risk of chloride-induced corrosion. When it comes to the sensitivity of parameters to service life, the effective diffusivity showed a marginal influence on serviceability, irrespective of GGBS contents while surface chloride content and critical threshold concentration revealed more crucial factors to long term chloride diffusion. As the GGBS replacement increased, the variation in service life has become less influential with changing parameters. Substantially, GGBS concrete at high replacement ratio enhanced the service life due to a combination of dense pore structure and enhanced chloride binding capacity.

  5. Effects of Experimental Parameters on the Extraction of Silica and Carbonation of Blast Furnace Slag at Atmospheric Pressure in Low-Concentration Acetic Acid

    Directory of Open Access Journals (Sweden)

    Kyungsun Song

    2017-05-01

    Full Text Available Blast furnace slag (BFS, a calcium-rich industrial byproduct, has been utilized since 2005 as a mineral carbonation feedstock for CO2 sequestration, producing calcium carbonate precipitates. In this study, the conditions for the dissolution of Ca and Si in acetic acid, and subsequent carbonation, were elaborated. For this purpose, the retardation of the polymerization of silicon was attempted by varying the concentration of acetic acid, temperature, and leaching time. An inductively coupled plasma (ICP analysis revealed that both the Ca and Si dissolved completely within 30 min in 5% acetic acid at room temperature. This high dissolution value can be attributed to the fact that Ca was bound to O rather than to Si, as determined by X-ray photoelectron spectroscopy (XPS. The use of CO2-absorbed monoethanolamine enabled the complete carbonation of BFS at ambient conditions without the need for a pH swing. The presence of dissolved silica was found to affect the polymorphs of the precipitated CaCO3. We believe that this process offers a simple method for manipulating the composites of products obtained by mineral carbonation diminishing the leaching residues.

  6. Effect of Slag Content and Hardening Accelerator Dosage on the Physico Mechanical Properties of Cement and Concrete

    International Nuclear Information System (INIS)

    Derabla, R.; Mokrani, I.; Benmalek, M.L.

    2011-01-01

    Our contribution consists at the study of the effect of (0 %, 0.2 % and 0.34 %) dosage of an hardening accelerating plasticizer (Plastocrete 160, produced by Sika Aldjazair) on the properties of normal mortar and concretes prepared with portland cement artificial of Hadjar Soud cement factory (Skikda - Algeria) with addition of (10 % and 20 %) of granulated blast furnace slag finely crushed of the El Hadjar blast furnace (Annaba - Algeria). The tests are focused to the physical and mechanical characteristics of elaborated materials to knowing: setting time, porosity, water absorption capacity and the test of compressive strength at 2, 7 and 28 days. The results obtained show clearly the reliability of the additive used to accelerate the hardening and to obtain high strengths at early age, which increase by increasing of the additive dosage. For the slag, its low hydraulic capacity does not make it profitable than at the long term (beyond 28 days). (author)

  7. Desempenho de telhas de escória de alto forno e fibras vegetais em protótipos de galpões Performance of tiles composed of blast furnace slag and vegetable fiber in prototype barns

    Directory of Open Access Journals (Sweden)

    Maristela N. da Conceição

    2008-10-01

    Full Text Available Busca-se, em todo o mundo, a substituição do cimento amianto por alternativas seguras para o ambiente e para a saúde do trabalhador, além de econômicas, razão por que o uso de fibras vegetais como aglomerado em países tropicais onde estes resíduos são abundantes, tem-se mostrado bastante viável. No presente experimento foram comparadas telhas de cimento amianto pintadas com tinta reflexiva, telhas cerâmicas e telhas compostas de uma matriz à base de cimento Portland CPII 32Z (ABNT NBR-5735, escória de alto-forno (EAF e sílica ativa, reforçadas com fibras de polpa celulósica de sisal (Agave sisalana. Utilizaram-se protótipos de galpões avícolas nos quais o calor produzido pelas aves foi simulado por lâmpadas incandescentes. Para caracterização do ambiente térmico lançou-se mão dos índices de conforto: ITU (índice de temperatura e umidade, ITGU (índice de temperatura de globo e umidade, CTR (carga térmica radiante e entalpia (H em que os resultados demonstraram que as telhas compostas apresentaram comportamento térmico semelhante ao das telhas cerâmicas, podendo ser utilizadas em substituição às telhas de cimento amianto.The substitution of cement asbestos by safer and equally economical alternatives has being searched for throughout the world. The usage of vegetal staple fiber as agglomerate in tropical countries where these residues are abundant has shown it self to be viable. In this study, roofing tiles fabricated with cement base Portland CPII 32Z (ABNT NBR-5735, blast furnace slag (EAF, active silica reinforced with cellulose pulp staple fibers of sisal (Agave sisalana were compared with cement asbestos roofing tiles with white paint and ceramic roofing tiles. Prototypes of poultry facilities were used and lamps simulated the heat produced by the birds. Indices ITU, ITGU, CTR and entalpy (H were employed for the characterization of the thermal atmospheric comfort and the results showed that the alternative

  8. Mechanical Properties of High Strength Mortars Made withFine Waste Concrete Aggregates and Ground Granulated Blast Furnace Slag

    Directory of Open Access Journals (Sweden)

    Ali Hassoon Nahhab

    2018-01-01

    Full Text Available The mechanical properties of high strength mortars produced with fine waste concrete aggregate (FWCA and GGBFS were investigated. The natural sand was replaced by FWCA with different levels, namely 0, 25, 50, 75, and 100%. The ordinary Portland cement (OPC was substituted by GGBFS with 0, 30, and 60% by weight. To satisfy the requirements of high strength, all the mortar mixes were made with a 0.25 w/bratio. The hardened mortars were tested for compressive strength, splitting tension, and fracture parametersat different ages.The experimental findings showed that the mixtures with FWCA showed lower strength, fracture energy and toughness compared to the corresponding reference mixes at a given age and GGBFS content. The 30% replacement of OPC by GGBFS improved the strengths of all mixes at 28 and 90 days. Moreover, the use of 30% GGBFS counterbalanced the strength decrement due to the use of the FWCA such that the mixtures with FWCA and GGBFS showed strengths comparable to or even exceeded the strengths of the mixtures made with natural sand only.

  9. Blast furnace hearth lining: post mortem analysis

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Bruno Vidal de; Vernilli Junior, Fernando, E-mail: bva@usp.br [Universidade de Sao Paulo (USP), Lorena, SP (Brazil). Escola de Engenharia; Neves; Elton Silva; Silva, Sidiney Nascimento [Companhia Siderugica Nacional (CSN), Rio de Janeiro, RJ (Brazil)

    2017-05-15

    The main refractory lining of blast furnace hearth is composed by carbon blocks that operates in continuous contact with hot gases, liquid slag and hot metal, in temperatures above 1550 deg C for 24 hours a day. To fully understand the wear mechanism that acts in this refractory layer system it was performed a Post Mortem study during the last partial repair of this furnace. The samples were collected from different parts of the hearth lining and characterized using the following techniques: Bulk Density and Apparent Porosity, X-Ray Fluorescence, X-ray Diffraction, Scanning Electron Microscopy with Energy-dispersive X-Ray Spectroscopy. The results showed that the carbon blocks located at the opposite side of the blast furnace tap hole kept its main physicochemical characteristics preserved even after the production of 20x10{sup 6} ton of hot metal. However, the carbon blocks around the Tap Hole showed infiltration by hot metal and slag and it presents a severe deposition of zinc and sulfur over its carbon flakes. The presence of these elements is undesired because it reduces the physic-chemical stability of this refractory system. This deposition found in the carbon refractory is associated with impurities present in the both coke and the sinter feed used in this blast furnace in the last few years. (author)

  10. Influence of slag chemistry on the hydration of alkali-activated blast-furnace slag - Part I: Effect of MgO

    International Nuclear Information System (INIS)

    Ben Haha, M.; Lothenbach, B.; Le Saout, G.; Winnefeld, F.

    2011-01-01

    The hydration and the microstructure of three alkali activated slags (AAS) with MgO contents between 8 and 13 wt.% are investigated. The slags were hydrated in the presence of two different alkaline activators, NaOH and Na 2 SiO 3 .5H 2 O (WG). Higher MgO content of the slag resulted in a faster reaction and higher compressive strengths during the first days. The formation of C(- A)-S-H and of a hydrotalcite-like phase was observed in all samples by X-ray diffraction (XRD), thermal analysis (TGA) and scanning electron microscopy (SEM) techniques. Increasing the MgO content of the slag from 8 to 13% increased the amount of hydrotalcite and lowered the Al uptake by C-S-H resulting in 9% higher volume of the hydrates and a 50 to 80% increase of the compressive strength after 28 days and longer for WG activated slag pastes. For NaOH activated slags only a slight increase of the compressive strength was measured.

  11. Influence of slag chemistry on the hydration of alkali-activated blast-furnace slag — Part II: Effect of Al2O3

    International Nuclear Information System (INIS)

    Ben Haha, M.; Lothenbach, B.; Le Saout, G.; Winnefeld, F.

    2012-01-01

    The hydration and microstructural evolution of three alkali activated slags (AAS) with Al 2 O 3 contents between 7 and 17% wt.% have been investigated. The slags were hydrated in the presence of two different alkaline activators, NaOH and Na 2 SiO 3 ·5H 2 O. The formation of C(-A)–S–H and hydrotalcite was observed in all samples by X-ray diffraction, thermal analysis and scanning electron microscopy. Higher Al 2 O 3 content of the slag decreased the Mg/Al ratio of hydrotalcite, increased the Al incorporation in the C(-A)-S-H and led to the formation of strätlingite. Increasing Al 2 O 3 content of the slag slowed down the early hydration and a lower compressive strength during the first days was observed. At 28 days and longer, no significant effects of slag Al 2 O 3 content on the degree of hydration, the volume of the hydrates, the coarse porosity or on the compressive strengths were observed.

  12. Evaluation of portland cement concrete pavement with high slag content cement.

    Science.gov (United States)

    2013-10-01

    The performance of a section of concrete pavement built with 30 percent Ground Granulated Blast Furnace Slag (GGBFS) is compared to a control section of concrete pavement built with 25 percent GGBFS to determine if the higher slag content pavement is...

  13. Chloride-binding Effect of Blast Furnace Slag in Cement Pastes ...

    African Journals Online (AJOL)

    The PDF file you selected should load here if your Web browser has a PDF reader plug-in installed (for example, a recent version of Adobe Acrobat Reader). If you would like more information about how to print, save, and work with PDFs, Highwire Press provides a helpful Frequently Asked Questions about PDFs.

  14. Chloride-binding Effect of Blast Furnace Slag in Cement Pastes ...

    African Journals Online (AJOL)

    NICO

    2017-05-16

    May 16, 2017 ... which chloride can be bound as Friedel's salt. The work of. Brown and Bothe1 and Siegwartet al.2 indicated that both the C3A and the C4AF phases contribute to chloride binding, although. C4AF to a lesser extent than the C3A.3 Birnin-Yauri and Glasser4 also suggested the formation of oxychloride ...

  15. Innovation based on tradition: blast furnace slag cement for durable concrete structures in Norway

    NARCIS (Netherlands)

    Polder, R.B.; Nijland, T.G.; Rooij, M.R. de; Larsen, C.K.; Pedersen, B.

    2014-01-01

    road environment in The Netherlands for nearly a century. The experience is good and structures with long service lives can be obtained, as has been shown by several field studies. This is caused by a high resistance against chloride penetration and a high electrical resistivity, demonstrated both

  16. Electrosynthesis of Ti5Si3, Ti5Si3/TiC, and Ti5Si3/Ti3SiC2 from Ti-Bearing Blast Furnace Slag in Molten CaCl2

    Science.gov (United States)

    Li, Shangshu; Zou, Xingli; Zheng, Kai; Lu, Xionggang; Chen, Chaoyi; Li, Xin; Xu, Qian; Zhou, Zhongfu

    2018-04-01

    Ti5Si3, Ti5Si3/TiC, and Ti5Si3/Ti3SiC2 have been electrochemically synthesized from the Ti-bearing blast furnace slag/TiO2 and/or C mixture precursors at a cell voltage of 3.8 V and 1223 K to 1273 K (950 °C to 1000 °C) in molten CaCl2. The pressed porous mixture pellets were used as the cathode, and a solid oxide oxygen-ion-conducting membrane (SOM)-based anode was used as the anode. The phase composition and morphologies of the cathodic products were systematically characterized. The final products possess a porous nodular microstructure due to the interconnection of particles. The variations of impurity elements, i.e., Ca, Mg, and Al, have been analyzed, and the result shows that Ca and Mg can be almost completely removed; however, Al cannot be easily removed from the pellet due to the formation of Ti-Al alloys during the electroreduction process. The electroreduction process has also been investigated by the layer-depended phase composition analysis of the dipped/partially reduced pellets to understand the detailed reaction process. The results indicate that the electroreduction process of the Ti-bearing blast furnace slag/TiO2 and/or C mixture precursors can be typically divided into four periods, i.e., (i) the decomposition of initial Ca(Mg,Al)(Si,Al)2O6, (ii) the reduction of Ti/Si-containing intermediate phases, (iii) the removal of impurity elements, and (iv) the formation of Ti5Si3, TiC, and Ti3SiC2. It is suggested that the SOM-based anode process has great potential to be used for the direct and facile preparation of Ti alloys and composites from cheap Ti-containing ores.

  17. The evolution of strength and crystalline phases for alkali-activated ground blast furnace slag and fly ash-based geopolymers

    Energy Technology Data Exchange (ETDEWEB)

    Jae Eun Oh; Paulo J.M. Monteiro; Ssang Sun Jun; Sejin Choi; Simon M. Clark [University of California, Berkeley, CA (United States). Department of Civil and Environmental Engineering

    2010-02-15

    The increase in strength and evolution of crystalline phases in inorganic polymer cement, made by the alkali activation of slag, Class C and Class F fly ashes, was followed using compressive strength test and synchrotron X-ray diffraction. In order to increase the crystallinity of the product the reactions were carried out at 80{sup o}C. We found that hydrotalcite formed in both the alkali-activated slag cements and the fly ash-based geopolymers. Hydroxycancrinite, one member of the ABC-6 family of zeolites, was found only in the fly ash geopolymers. Assuming that the predominantly amorphous geopolymer formed under ambient conditions relates to the crystalline phases found when the mixture is cured at high temperature, we propose that the structure of this zeolitic precursor formed in Na-based high alkaline environment can be regarded as a disordered form of the basic building unit of the ABC-6 group of zeolites which includes poly-types such as hydroxycancrinite, hydroxysodalite and chabazite-Na.

  18. The evolution of strength and crystalline phases for alkali-activated ground blast furnace slag and fly ash-based geopolymers

    KAUST Repository

    Oh, Jae Eun

    2010-02-01

    The increase in strength and evolution of crystalline phases in inorganic polymer cement, made by the alkali activation of slag, Class C and Class F fly ashes, was followed using compressive strength test and synchrotron X-ray diffraction. In order to increase the crystallinity of the product the reactions were carried out at 80 °C. We found that hydrotalcite formed in both the alkali-activated slag cements and the fly ash-based geopolymers. Hydroxycancrinite, one member of the ABC-6 family of zeolites, was found only in the fly ash geopolymers. Assuming that the predominantly amorphous geopolymer formed under ambient conditions relates to the crystalline phases found when the mixture is cured at high temperature, we propose that the structure of this zeolitic precursor formed in Na-based high alkaline environment can be regarded as a disordered form of the basic building unit of the ABC-6 group of zeolites which includes poly-types such as hydroxycancrinite, hydroxysodalite and chabazite-Na. © 2009 Elsevier Ltd.

  19. The evolution of strength and crystalline phases for alkali-activated ground blast furnace slag and fly ash-based geopolymers

    International Nuclear Information System (INIS)

    Oh, Jae Eun; Monteiro, Paulo J.M.; Jun, Ssang Sun; Choi, Sejin; Clark, Simon M.

    2010-01-01

    The increase in strength and evolution of crystalline phases in inorganic polymer cement, made by the alkali activation of slag, Class C and Class F fly ashes, was followed using compressive strength test and synchrotron X-ray diffraction. In order to increase the crystallinity of the product the reactions were carried out at 80 deg. C. We found that hydrotalcite formed in both the alkali-activated slag cements and the fly ash-based geopolymers. Hydroxycancrinite, one member of the ABC-6 family of zeolites, was found only in the fly ash geopolymers. Assuming that the predominantly amorphous geopolymer formed under ambient conditions relates to the crystalline phases found when the mixture is cured at high temperature, we propose that the structure of this zeolitic precursor formed in Na-based high alkaline environment can be regarded as a disordered form of the basic building unit of the ABC-6 group of zeolites which includes poly-types such as hydroxycancrinite, hydroxysodalite and chabazite-Na.

  20. THE IMPACT OF DISSOLVED SALTS ON PASTES CONTAINING FLY ASH, CEMENT AND SLAG

    Energy Technology Data Exchange (ETDEWEB)

    Harbour, J.; Edwards, T.; Williams, V.

    2009-09-21

    The degree of hydration of a mixture of cementitious materials (Class F fly ash, blast furnace slag and portland cement) in highly concentrated alkaline salt solutions is enhanced by the addition of aluminate to the salt solution. This increase in the degree of hydration, as monitored with isothermal calorimetry, leads to higher values of dynamic Young's modulus and compressive strength and lower values of total porosity. This enhancement in performance properties of these cementitious waste forms by increased hydration is beneficial to the retention of the radionuclides that are also present in the salt solution. The aluminate ions in the solution act first to retard the set time of the mix but then enhance the hydration reactions following the induction period. In fact, the aluminate ions increase the degree of hydration by {approx}35% over the degree of hydration for the same mix with a lower aluminate concentration. An increase in the blast furnace slag concentration and a decrease in the water to cementitious materials ratio produced mixes with higher values of Young's modulus and lower values of total porosity. Therefore, these operational factors can be fine tuned to enhance performance properties of cementitious waste form. Empirical models for Young modulus, heat of hydration and total porosity were developed to predict the values of these properties. These linear models used only statistically significant compositional and operational factors and provided insight into those factors that control these properties.

  1. Effects of slag and fly ash on reinforcement corrosion in concrete in chloride environment : Research from the Netherlands

    NARCIS (Netherlands)

    Polder, R.B.

    2012-01-01

    A review is given of research on the durability performance of concrete made with blast furnace slag and fly ash related to chloride induced reinforcement corrosion, carried out in the Netherlands, where slag has been used in cement for almost a century. Results are presented from field studies on

  2. Effects of slag and fly ash on reinforcement corrosion in concrete in chloride environment. Research from the Netherlands

    NARCIS (Netherlands)

    Polder, R.B.

    2012-01-01

    A review is given of research on the durability performance of concrete made with blast furnace slag and fly ash related to chloride induced reinforcement corrosion, carried out in the Netherlands, where slag has been used in cement for almost a century. Results are presented from field studies on

  3. physico-chemical studies on polymer impregnated blending cement mortar composite

    International Nuclear Information System (INIS)

    Abdel-Rahman, H.A.

    2001-01-01

    as the increasing of the demand on a specific performance characteristics in concrete such as improved strength, low heat, sulfate resistance, improved impermeability and certain other applications. some of the industrial waste materials such as the blast-furnace slag, silica fume and fly ash were mixed with the cement clinker to produce blended cement . the use of these materials modifies the strength, pore structure and permeability of hardened cement mortar or concrete. the incorporation of blast furnace slag and silica fume in the hardened blended cement mortar or concrete is a common practice recently due to technological, economical and environmental benefits

  4. Changes in water absorptivity of slag based cement mortars exposed to sulphur-oxidising A. thiooxidans bacteria

    Science.gov (United States)

    Estokova, A.; Smolakova, M.; Luptakova, A.; Strigac, J.

    2017-10-01

    Water absorptivity is heavily influenced by the volume and connectivity of pores in the pore network of cement composites and has been used as an important parameter for quantifying their durability. To improve the durability and permeability of mortars, various mineral admixtures such as furnace slag, silica fume or fly ash are added into the mortar and concrete mixtures. These admixtures provide numerous important advantages such as corrosion control, improvement of mechanical and physical properties and better workability. This study investigated the changes in absorptivity of cement mortars with different amounts of mineral admixture, represented by granulated blast furnace slag, under aggressive bacterial influence. The water absorptivity of mortars specimens exposed to sulphur-oxidising bacteria A. thiooxidans for the period of 3 and 6 months has changed due to bio-corrosion-based degradation process. The differences in water absorptivity in dependence on the mortars composition have been observed.

  5. Mechanical and leaching behaviour of slag-cement and lime-activated slag stabilised/solidified contaminated soil.

    Science.gov (United States)

    Kogbara, Reginald B; Al-Tabbaa, Abir

    2011-05-01

    Stabilisation/solidification (S/S) is an effective technique for reducing the leachability of contaminants in soils. Very few studies have investigated the use of ground granulated blast furnace slag (GGBS) for S/S treatment of contaminated soils, although it has been shown to be effective in ground improvement. This study sought to investigate the potential of GGBS activated by cement and lime for S/S treatment of a mixed contaminated soil. A sandy soil spiked with 3000mg/kg each of a cocktail of heavy metals (Cd, Ni, Zn, Cu and Pb) and 10,000mg/kg of diesel was treated with binder blends of one part hydrated lime to four parts GGBS (lime-slag), and one part cement to nine parts GGBS (slag-cement). Three binder dosages, 5, 10 and 20% (m/m) were used and contaminated soil-cement samples were compacted to their optimum water contents. The effectiveness of the treatment was assessed using unconfined compressive strength (UCS), permeability and acid neutralisation capacity (ANC) tests with determination of contaminant leachability at the different acid additions. UCS values of up to 800kPa were recorded at 28days. The lowest coefficient of permeability recorded was 5×10(-9)m/s. With up to 20% binder dosage, the leachability of the contaminants was reduced to meet relevant environmental quality standards and landfill waste acceptance criteria. The pH-dependent leachability of the metals decreased over time. The results show that GGBS activated by cement and lime would be effective in reducing the leachability of contaminants in contaminated soils. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. CFD‐DEM modelling of blast furnace tapping

    OpenAIRE

    Vango, Mathias; Pirker, Stefan; Lichtenegger, Thomas

    2017-01-01

    The campaign length of a blast furnace is limited by the hearth inner lining lifetime. In order to maximize the campaign length and ensure a good draining of hot metal and slag, a good understanding of the flow in the hearth is essential. Challenges in modelling the flow involve several continuous phases (hot metal, slag and hot blast) as well as the presence of the deadman, a dense bed of coke particles. The shape and position of the deadman depend on the weight of the burden column above an...

  7. Alkaline carbonates in blast furnace process

    Directory of Open Access Journals (Sweden)

    P. Besta

    2014-10-01

    Full Text Available The production of iron in blast furnaces is a complex of physical, chemical and mechanical processes. The input raw materials contain not only metallic components, but also a number of negative elements. The most important negative elements include alkaline carbonates. They can significantly affect the course of the blast furnace process and thus the overall performance of the furnace. As a result of that, it is essential to accurately monitor the alkali content in the blast furnace raw materials. The article analyzes the alkali content in input and output raw materials and their impact on the blast furnace process.

  8. Corrosion rate of rebars from linear polarization resistance and destructive analysis in blended cement concrete after chloride loading

    NARCIS (Netherlands)

    Polder, R.B.; Peelen, W.H.A.; Bertolini, L.; Guerriere, M.

    2002-01-01

    Concrete specimens with various binders including Portland cement, fly ash, blast furnace slag and composite cement and three water-to-cement ratios were subjected to cyclic wetting with salt solution and drying. Specimens contained six mild steel bars at two cover depths and two activated titanium

  9. Properties of paving units incorporating slag cement

    Directory of Open Access Journals (Sweden)

    Hanan A. El Nouhy

    2013-04-01

    Full Text Available The aim of this study is to investigate the effect and possibility of using Portland slag cement in the production of interlocking paving units. Paving units consist of two layers. Four mixes were cast. The first mix was the control mix, in which Portland cement was used in the two layers. In the second mix, Portland slag cement was used in the upper layer, Portland cement was used in the backing layer. In the third mix, Portland cement was placed in the upper layer, while Portland slag cement was used in the backing layer. Finally, in the fourth mix, Portland cement was fully replaced by Portland slag cement in both layers. Tests were carried out in order to investigate the properties of the manufactured specimens at ages 28 and 180 days, respectively. Compressive strength and abrasion resistance were conducted according to the American Society for Testing and Materials (ASTM C 140 and ASTM C418. Water absorption, split tensile strength, abrasion resistance, as well as, skid resistance were performed according to both Egyptian Standard Specifications (ESS 4382 and European Standard (EN 1338. The Egyptian standard is identical with the European standard. The results indicate that it is feasible to use Portland slag cement in the manufacture of paving blocks as the conditions of the conducted tests were satisfied at age180 days except for the minimum splitting tensile strength test.

  10. Influence of nucleation seeding on the compressive strength of ordinary Portland cement and alkali activated blast-furnace slag

    Science.gov (United States)

    2011-05-10

    The Intelligent Transportation Systems (ITS) Joint Program Office (JPO) of the U.S. Department of Transportation (USDOT) has been collecting the benefits, costs, lessons learned, and deployment status information of ITS. Such information, intended to...

  11. Avaliação das possibilidades de escórias de siderurgia como corretivos da acidez do solo Evaluation of blast furnace slags as correctives for soil acidity

    Directory of Open Access Journals (Sweden)

    Antônio Carlos Pimentel Wutke

    1962-01-01

    .This paper presents preliminary results obtained in a greenhouse test in which blast furnace slags and other lime materials were compared as soil correctives. Comparisons were made between dolomitic limestone, calcitic limestone, oyster-shell lime, slag from iron production and slag from steel production by the Martin-Siemens basic procedure. These materials were compared at two different rates. General application of NPK fertilizers was made and the control treatment received no lime. The soybean variety Abura (Glycine max (L. Merril was utilized as an indicator plant; four plants were grown in each pot. Final grain production was measured and soil samples were collected, from the pots, in order to check the pH and exchangeable acidity (H+ + Al+3. The results obtained showed that under the conditions of the test, the dolomitic limestone, the calcitic limestone and the oyster-shell lime were all equally efficient in their corrective effect. The slag from steel production showed an intermediary effect, while the slag from iron prodution appeared to be the least efficient. The grain yield from these treatments did not presente any statistically significant difference. The actual grinding of the materials used in the experiment seemed satisfactory. A finer grinding is not deemed necessary unless it is required by the legislation covering the commerce of soil correctives.

  12. Rheological Properties of Cemented Tailing Backfill and the Construction of a Prediction Model

    OpenAIRE

    Lang, Liu; Song, KI-IL; Lao, Dezheng; Kwon, Tae-Hyuk

    2015-01-01

    Workability is a key performance criterion for mining cemented tailing backfill, which should be defined in terms of rheological parameters such as yield stress and plastic viscosity. Cemented tailing backfill is basically composed of mill tailings, Portland cement, or blended cement with supplementary cement material (fly ash and blast furnace slag) and water, among others, and it is important to characterize relationships between paste components and rheological properties to optimize the w...

  13. Automated information system for analysis and prediction of production situations in blast furnace plant

    Science.gov (United States)

    Lavrov, V. V.; Spirin, N. A.

    2016-09-01

    Advances in modern science and technology are inherently connected with the development, implementation, and widespread use of computer systems based on mathematical modeling. Algorithms and computer systems are gaining practical significance solving a range of process tasks in metallurgy of MES-level (Manufacturing Execution Systems - systems controlling industrial process) of modern automated information systems at the largest iron and steel enterprises in Russia. This fact determines the necessity to develop information-modeling systems based on mathematical models that will take into account the physics of the process, the basics of heat and mass exchange, the laws of energy conservation, and also the peculiarities of the impact of technological and standard characteristics of raw materials on the manufacturing process data. Special attention in this set of operations for metallurgic production is devoted to blast-furnace production, as it consumes the greatest amount of energy, up to 50% of the fuel used in ferrous metallurgy. The paper deals with the requirements, structure and architecture of BF Process Engineer's Automated Workstation (AWS), a computer decision support system of MES Level implemented in the ICS of the Blast Furnace Plant at Magnitogorsk Iron and Steel Works. It presents a brief description of main model subsystems as well as assumptions made in the process of mathematical modelling. Application of the developed system allows the engineering and process staff to analyze online production situations in the blast furnace plant, to solve a number of process tasks related to control of heat, gas dynamics and slag conditions of blast-furnace smelting as well as to calculate the optimal composition of blast-furnace slag, which eventually results in increasing technical and economic performance of blast-furnace production.

  14. Packing issue in cement blending for sustainability developments - Approach by discrete element method

    NARCIS (Netherlands)

    Le, L.B.N.; Stroeven, P.

    2014-01-01

    Common cement blending materials for concrete like fly ashes, blast furnace slag, silica fume, metakaolin and rice husk ash have been investigated experimentally as to their impact on concrete’s mechanical, physical and sustainability capabilities. Such efforts offer but case-related information on

  15. The incorporation of low and medium level radioactive wastes (solids and liquids) in cement

    International Nuclear Information System (INIS)

    Palmer, J.D.; Smith, D.L.

    1985-07-01

    Experimentation has shown that high temperatures generated during the setting of ordinary Portland cement/simulant waste mixes can be significantly reduced by the use of a blend of ground granulated blast furnace slag and ordinary Portland cement. Trials on simulated waste showed that blended cement gave improved stability and a reduction in leach rates, and confirmed that the cement-based process can be used for the immobilisation of most types of low and medium level waste. (U.K.)

  16. Development of alkali activated cements and concrete mixture design with high volumes of red mud

    OpenAIRE

    Krivenko, Pavel; Kovalchuk, Oleksandr; Pasko, Anton; Croymans, Tom; Hutt, Mikael; Lutter, Guillaume; Vandevenne, Niels; Schreurs, Sonja; Schroeyers, Wouter

    2017-01-01

    Dedicated cement compositions were formulated to enable the incorporation of large volume fractions of red mud in alkali activated cements, taking into account the role of the aluminosilicate phase in the processes of hydration and hardening. High volume red mud alkali activated cements were synthesized using a proper combination of red mud, low basic aluminosilicate compounds with a glass phase (blast-furnace slag) and additives selected from high-basic Ca-containing cements with a crystalli...

  17. Cement/slag chemistry studies

    International Nuclear Information System (INIS)

    Glasser, F.P.; Macphee, D.; Atkins, M.; Beckley, N.; Carson, S.O.; Wilding, C.R.; McHugh, G.

    1988-01-01

    The performance of cement-based matrices intended for radwaste immobilization is assessed. The long-term performance of the matrix is characterized by thermodynamic evaluation of experimental data. The results are presented in a general form, amenable to a range of specific formulations. The interaction of specific radwaste components with cements has been studied, using Iodine as an example. It occurs as both I - and IO 3 - species, but these differ sharply in sorption characteristics. The effect of ionizing radiation of the pH and E h of cement matrices is reported. (author)

  18. Cement-based processes for the immobilization of intermediate level radioactive waste

    International Nuclear Information System (INIS)

    Brown, D.J.; Lee, D.J.; Price, M.S.T.; Smith, D.L.G.

    1985-01-01

    Increasing attention is being paid to the use of cement-based materials for the immobilisation of intermediate level wastes. Various cementitious materials are surveyed and the use of blast furnace slag is shown to be advantageous. The properties of cemented wastes are surveyed both during processing and as solid products. The application of Winfrith Cementation Laboratory technology to plant and flowsheet development for Winfrith Reactor sludge immobilisation is described. (author)

  19. Alkali-slag cements for the immobilization of radioactive wastes

    International Nuclear Information System (INIS)

    Shi, C.; Day, R.L.

    1996-01-01

    Alkali-slag cements consist of glassy slag and an alkaline activator and can show both higher early and later strengths than Type III Portland cement, if a proper alkaline activator is used. An examination of microstructure of hardened alkali-slag cement pastes with the help of XRD and SEM with EDAX shows that the main hydration product is C-S-H (B) with low C/S ratio and no crystalline substances exist such as Ca(OH) 2 , Al (OH) 3 and sulphoaluminates. Mercury intrusion tests indicate that hardened alkali-slag cement pastes have a lower porosity than ordinary Portland cement, and contain mainly gel pores. The fine pore structure of hardened alkali-slag cement pastes will restrict the ingress of deleterious substances and the leaching of harmful species such as radionuclides. The leachability of Cs + from hardened alkali-slag cement pastes is only half of that from hardened Portland cement. From all these aspects, it is concluded that alkali-slag cements are a better solidification matrix than Portland cement for radioactive wastes

  20. Thermodynamic modelling of alkali-activated slag cements

    International Nuclear Information System (INIS)

    Myers, Rupert J.; Lothenbach, Barbara; Bernal, Susan A.; Provis, John L.

    2015-01-01

    Highlights: • A thermodynamic modelling analysis of alkali-activated slag cements is presented. • Thermodynamic database describes zeolites, alkali carbonates, C–(N–)A–S–H gel. • Updated thermodynamic model for Mg–Al layered double hydroxides. • Description of phase assemblages in Na 2 SiO 3 - and Na 2 CO 3 -activated slag cements. • Phase diagrams for NaOH-activated and Na 2 SiO 3 -activated slag cements are simulated. - Abstract: This paper presents a thermodynamic modelling analysis of alkali-activated slag-based cements, which are high performance and potentially low-CO 2 binders relative to Portland cement. The thermodynamic database used here contains a calcium (alkali) aluminosilicate hydrate ideal solid solution model (CNASH-ss), alkali carbonate and zeolite phases, and an ideal solid solution model for a hydrotalcite-like Mg–Al layered double hydroxide phase. Simulated phase diagrams for NaOH- and Na 2 SiO 3 -activated slag-based cements demonstrate the high stability of zeolites and other solid phases in these materials. Thermodynamic modelling provides a good description of the chemical compositions and types of phases formed in Na 2 SiO 3 -activated slag cements over the most relevant bulk chemical composition range for these cements, and the simulated volumetric properties of the cement paste are consistent with previously measured and estimated values. Experimentally determined and simulated solid phase assemblages for Na 2 CO 3 -activated slag cements were also found to be in good agreement. These results can be used to design the chemistry of alkali-activated slag-based cements, to further promote the uptake of this technology and valorisation of metallurgical slags

  1. Optimization and characterization of a cemented ultimate-storage product

    Science.gov (United States)

    Brunner, H.

    1981-12-01

    The U- and Pu-containing packaging wastes can be homogeneously cemented after a washing and fragmentation process. Both finely crushed and coarsely fragmented raw wastes yield products with sufficient mechanical stability. The processability limit of the coarsely fragmented raw waste using cement paste or mortar is largely determined by the cellulose content, which is not to exceed 1.3% by weight in the end waste. Of 9 binders studied, the most corrosion-resistant products were obtained with blast-furnace slag cement, whereas poured concrete and Maxit are much less resistant in five-component brine. In the cemented product, hydrolysis of plasticizers (DOP) from plastics (PVC) occurs, leading to release of 2-ethyl-hexanol. This reaction occurs to a much lower degree with blast-furnace slag cement than with all other binders studied. The binder chosen for further tests consists of blast-furnace slag cement, concrete fluidizer and a stabilizer, and is processed at a W/C ratio of 0.43.

  2. Degradation of normal portland and slag cement concrete under load, due to reinforcement corrosion

    International Nuclear Information System (INIS)

    Philipose, K.E.; Beaudoin, J.J.; Feldman, R.F.

    1992-08-01

    The corrosion of reinforcement is one of the major degradation mechanisms of reinforced concrete elements. The majority of studies published on concrete-steel corrosion have been conducted on unstressed specimens. Structural concrete, however, is subjected to substantial strain near the steel reinforcing bars that resist tensile loads, which results in a system of microcracks. This report presents the initial results of an investigation to determine the effect of applied load and microcracking on the rate of ingress of chloride ion and corrosion of steel in concrete. Simply-supported concrete beam specimens were loaded to give a maximum strain of about 600 με on the tension face. Chloride ion ingress on cores taken from loaded specimens was monitored using energy-dispersive X-ray analysis techniques. Corrosion current and rate measurements using linear polarization electrochemical techniques were also obtained on the same loaded specimens. Variables investigated included two concrete types, two steel cover-depths, three applied load levels, bonded and unbonded rebars and the exposure of tension and compression beam faces to chloride solution. One concrete mixture was made with type 10 Portland cement, the other with 75% blast furnace slag, 22% type 50 cement and 3% silica fume. The rate of chloride ion ingress into reinforced concrete, and hence the time for chloride ion to reach the reinforcing steel, is shown to be dependent on applied load and the concrete quality. The dependence of corrosion process descriptors - passive layer formation, initiation period and propagation period - on the level of applied load is discussed. (Author) (6 refs., 3 tabs., 10 figs.)

  3. Constructal design of a blast furnace iron-making process based on multi-objective optimization

    International Nuclear Information System (INIS)

    Liu, Xiong; Chen, Lingen; Feng, Huijun; Qin, Xiaoyong; Sun, Fengrui

    2016-01-01

    For the fixed total raw material cost and based on constructal theory and finite time thermodynamics, a BFIM (blast furnace iron-making) process is optimized by taking a complex function as optimization objective. The complex function is integrated with HM (hot metal) yield and useful energy of the BF (blast furnace). The optimal cost distribution of raw materials (namely “generalized optimal construct”) is obtained. The effects of some parameters, such as oxygen enrichment, blast temperature and pulverized coal dosage, on the optimization results are analyzed. The results show that the HM yield, useful energy and complex function are, respectively, increased by 3.13%, 2.66% and 2.90% after generalized constructal optimization. The utilization efficiencies of the BFG (blast furnace gas) and slag are 41.3% and 57.1%, respectively, which means that the utilization potentials of the BFG and slag can be further exploited. Increasing pulverized coal dosage and decreasing the agglomerate ratio can increase the complex function. The performance the BFIM process can be improved by adjusting the oxygen enrichment, blast temperature, blast dosage, pressure ratio of the Brayton cycle's air compressor and relative pressure drop of the air compressor inlet to their optimal values, respectively, which are new findings of this paper. - Highlights: • Constructal optimization of a blast furnace iron-making process is performed. • Finite time thermodynamic model of open Brayton cycle is adopted. • Weighting function is taken as optimization objective. • Optimal cost distribution of the raw materials is obtained.

  4. Skid resistance performance of asphalt wearing courses with electric arc furnace slag aggregates.

    Science.gov (United States)

    Kehagia, Fotini

    2009-05-01

    Metallurgical slags are by-products of the iron and steel industry and are subdivided into blast furnace slag and steel slag according to the different steel-producing processes. In Greece, slags are mostly produced from steelmaking using the electric arc furnace process, and subsequently are either disposed in a random way or utilized by the cement industry. Steel slag has been recently used, worldwide, as hard aggregates in wearing courses in order to improve the skidding resistance of asphalt pavements. At the Highway Laboratory, Department of Civil Engineering of Aristotle University of Thessaloniki research has been carried out in the field of steel slags, and especially in electric arc furnace (EAF) slag, to evaluate their possible use in highway engineering. In this paper, the recent results of anti-skidding performance of steel slag aggregates in highway pavements are presented.

  5. The incorporation of low and medium level radioactive wastes (solids and liquids) in cement

    International Nuclear Information System (INIS)

    Brown, D.J.; Capp, P.D.; Smith, D.L.

    1982-08-01

    Laboratory studies and mixing plant trials on simulated radioactive waste formulations are reported. Long term stability testing of various formulations including those containing blast furnace slag-ordinary Portland cement, sodium nitrate, ion exchange resins, and sodium nitrate-tributyl phosphate, are reported and some results are given. Mixing plant trials with a high shear cement mixer are reported. An outline of future work is presented. (U.K.)

  6. Carbon Tubular Morphologies in Blast Furnace Coke

    Directory of Open Access Journals (Sweden)

    Stanislav S. Gornostayev

    2008-01-01

    Full Text Available The paper reports on the first occurrence of microscale carbon tubular morphologies (CMTs in a blast furnace (BF coke. The CMTs were probably formed as a result of the conversion of solid disordered carbon via liquid phase metal particles involving a gas phase containing a substantial amount of N2 and O2. The presence of CMTs may lie behind the generation of the smallest fraction of fines in BF exhaust dust. If the amount of CMTs present in the BF exhausts gases at any particular metallurgical site proves to be substantial, it could become a subject of environmental concern.

  7. Immobilisation of ion exchange resins in cement

    International Nuclear Information System (INIS)

    Howard, C.G.; Jolliffe, C.B.; Lee, D.J.

    1990-09-01

    The removal of activity from spent decontaminating solutions eg LOMI can be achieved using organic ion exchange resins. These resins can be successfully immobilised in cement based matrices. The optimum cement system contained 10% ordinary Portland cement 84% gg blast furnace slag, 6% microsilica with a water cement ratio of 0.5 and a dry resin loading of 36% with respect to total weight. This formulation was successfully scaled up to 200 litres giving a product with acceptable compressive strength, dimensional stability and elastic modulus. Storage of samples under water appears to have no detrimental effects on the product's properties. (author)

  8. Thermal properties of fly ash substituted slag cement waste forms for disposal of Savannah River Plant salt waste

    International Nuclear Information System (INIS)

    Roy, D.M.; Kaushal, S.; Licastro, P.H.; Langton, C.A.

    1985-01-01

    Waste processing at the Savannah River Plant will involve reconstitution of the salts (NaNO 3 , NaNO 2 , NaOH, etc.) into a concentrated solution (32 weight percent salts) followed by solidification in a cement-based waste form for burial. The stability and mechanical durability of such a 'saltstone monolith' will depend largely on the temperature reached due to heat of hydration and the thermal properties of the waste form. Fly ash has been used as an inexpensive constituent and to moderate the hydration and setting processes so as to avoid reaching prohibitively high temperatures which could cause thermal stresses. Both high-calcium and low-calcium fly ashes have been studied for this purpose. Other constituents of these mixes include granulated blast furnace slag and finely crushed limestone. Adiabatic temperature increase and thermal conductivity of these mixes have been studied and related x-ray diffraction and scanning electron microscopy studies carried out to understand the hydration process

  9. Analysis of the Optimum Usage of Slag for the Compressive Strength of Concrete.

    Science.gov (United States)

    Lee, Han-Seung; Wang, Xiao-Yong; Zhang, Li-Na; Koh, Kyung-Taek

    2015-03-18

    Ground granulated blast furnace slag is widely used as a mineral admixture to replace partial Portland cement in the concrete industry. As the amount of slag increases, the late-age compressive strength of concrete mixtures increases. However, after an optimum point, any further increase in slag does not improve the late-age compressive strength. This optimum replacement ratio of slag is a crucial factor for its efficient use in the concrete industry. This paper proposes a numerical procedure to analyze the optimum usage of slag for the compressive strength of concrete. This numerical procedure starts with a blended hydration model that simulates cement hydration, slag reaction, and interactions between cement hydration and slag reaction. The amount of calcium silicate hydrate (CSH) is calculated considering the contributions from cement hydration and slag reaction. Then, by using the CSH contents, the compressive strength of the slag-blended concrete is evaluated. Finally, based on the parameter analysis of the compressive strength development of concrete with different slag inclusions, the optimum usage of slag in concrete mixtures is determined to be approximately 40% of the total binder content. The proposed model is verified through experimental results of the compressive strength of slag-blended concrete with different water-to-binder ratios and different slag inclusions.

  10. Properties and application of carbon composite brick for blast furnace hearth

    Directory of Open Access Journals (Sweden)

    Jiao K.X.

    2015-01-01

    Full Text Available A type of carbon composite brick was produced via the microporous technique using natural flack graphite, α-Al2O3 and high-quality bauxite chamotte (Al2O3≥87 mass% as raw materials with fine silicon powder as additive. The composition and microstructure of the obtained carbon composite were characterized using chemical analysis, XRD and SEM with EDS. The high temperature properties of thermal conductivity, oxidization and corrosion by molten slag and hot metal of the composite were analyzed. Based on these, the type of carbon composite brick worked in a blast furnace hearth for six years was further sampled at different positions. The protective layer was found and its chemical composition and microscopic morphology were investigated. It is found that the carbon composite brick combines the good properties of both the conventional carbon block and ceramic cup refractory. The protective layer near the hot face consists of two separated sublayers, i.e. the slag layer and the carbon layer. A certain amount of slag phase is contained in the carbon layer, which is caused by the reaction of coke ash with the refractory. No obvious change in the chemical composition of the protective layer along the depth of the sidewall is found. This work provides a useful guidance for the extension of the lifetime of blast furnace hearths.

  11. The hydration of slag, part 2: reaction models for blended cement

    NARCIS (Netherlands)

    Chen, Wei; Brouwers, Jos

    2007-01-01

    The hydration of slag-blended cement is studied by considering the interaction between the hydrations of slag and Portland cement clinker. Three reaction models for the slag-blended cement are developed based on stoichiometric calculations. These models correlate the compositions of the unhydrated

  12. Pellet reduction properties under different blast furnace operating conditions

    OpenAIRE

    Leimalm, Ulrika

    2006-01-01

    One of the aims of modern blast furnace (BF) ironmaking is to reduce coke consumption. One way is to increase the injection of reduction agents, such as pulverized coal. An increase in pulverized coal injection rate (PCR) will affect the blast furnace process and the conditions for iron oxide reduction. Changes in PCR influence the composition of the ascending gases and the in-furnace temperature isotherms. The performed tests involve full-scale, pilot and laboratory investigations. Raw mater...

  13. Mathematical model and software for control of commissioning blast furnace

    Science.gov (United States)

    Spirin, N. A.; Onorin, O. P.; Shchipanov, K. A.; Lavrov, V. V.

    2016-09-01

    Blowing-in is a starting period of blast furnace operation after construction or major repair. The current approximation methods of blowing-in burden analysis are based on blowing-in practice of previously commissioned blast furnaces. This area is theoretically underexplored; there are no common scientifically based methods for selection of the burden composition and blast parameters. The purpose of this paper is development and scientific substantiation of the methods for selection of the burden composition and blast parameters in the blast furnace during the blowing-in period. Research methods are based on physical regularities of main processes running in the blast furnace, system analysis, and application of modern principles for development and construction of mathematical models, algorithms and software designed for automated control of complex production processes in metallurgy. As consequence of the research made by the authors the following results have been achieved: 1. A set of mathematical models for analysis of burden arrangement throughout the height of the blast furnace and for selection of optimal blast and gas dynamic parameters has been developed. 2. General principles for selection of the blowing-in burden composition and blast and gas dynamic parameters have been set up. 3. The software for the engineering and process staff of the blast furnace has been developed and introduced in the industry.

  14. Use of blastfurnace slag, a by-product of the steel industry, for road construction purposes

    Energy Technology Data Exchange (ETDEWEB)

    Matinheikki, J. [Finnish National Road Administration, Oulu Region Oulu (Finland)

    2000-07-01

    The development of blast furnace slag sand stabilisation began in the middle of the 1980's. The objective was to develop a method to prevent the damage of the load-bearing layers top part (rock materials pulverisation). With cooperation of Rautaruukki Oy and SKI Company a method was developed which fulfills the given edge conditions. At the same time an environment friendly method was achieved which makes good use of industrial by-product, blast furnace slag. The new method clearly increase the lifetime of the structure. The use of blast furnace slag sand stabilisation expanded in 1991 when more powerful rotavators for stabilisation work were available. The compression strength of the stabilised material, soil cement, at the age of 90 days is 3,0 MPa. The bearing values at the age on one year have been from 700-800 MN/m{sup 2}. Another good property is its ability to reset if the stabilised structure is damaged (cracked). The method has been used mainly in the Northern Finland area, but nowadays the economic range of use is the whole country. (orig.)

  15. Use of ancient copper slags in Portland cement and alkali activated cement matrices.

    Science.gov (United States)

    Nazer, Amin; Payá, Jordi; Borrachero, María Victoria; Monzó, José

    2016-02-01

    Some Chilean copper slag dumps from the nineteenth century still remain, without a proposed use that encourages recycling and reduces environmental impact. In this paper, the copper slag abandoned in landfills is proposed as a new building material. The slags studied were taken from Playa Negra and Púquios dumps, both located in the region of Atacama in northern Chile. Pozzolanic activity in lime and Portland cement systems, as well as the alkali activation in pastes with copper slag cured at different temperatures, was studied. The reactivity of the slag was measured using thermogravimetric analysis (TGA), scanning electron microscopy (SEM), X-ray diffraction (XRD), electrical conductivity and pH in aqueous suspension and Fourier Transform Infrared Spectroscopy (FTIR). Furthermore, copper slag-Portland cement mortars with the substitution of 25% (by weight) of cement by copper slag and alkali-activated slag mortars cured at 20 and 65 °C were made, to determine the compressive strength. The results indicate that the ancient copper slags studied have interesting binding properties for the construction sector. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Investigation of accretion formation in a blast furnace shaft

    Energy Technology Data Exchange (ETDEWEB)

    Klima, R.; Hoefer, O.; Chiarotti, U.; Fredman, T.; Hillmann, C.; Raipala, K.; Eriksson, J. (eds.) [BFI Duesseldorf (Germany)

    2005-07-01

    Accretions in the bosh, belly and shaft have a significant influence on blast furnace performance and on the service life of the refractory lining and the cooling system. To analyse the mechanisms of formation and dislodging of accretions, investigations were carried out at four different blast furnaces. Three blast furnaces were equipped with additional measurements to investigate the accretion formation process and to provide information for the development of accretion estimation models. Installation activities included thermocouples, heat-flux meters, staves with instrumentation for heat-flux measurement and a small horizontal lance. The distribution of accretions in the shaft was documented. Samples were taken out of accretions during blast furnace stoppages. Their acquisition was simplified with newly developed sampling devices. The samples were analysed to determine chemical and mineralogical properties and thermal conductivity. Samples were mainly made up of reduced iron or of coke and sinter structures glued together by zinc or alkali compounds. Together with a newly developed offline model for the simulation of accretion formation, different parameters influencing the formation process were identified. The main parameters are: burden material composition, blast furnace operating conditions; and the cooling system. Countermeasures to prevent excessive accretion growth were determined. They offer a better operational control of accretions. Different models to identify accretion formation were developed and an overview was presented. Different models were necessary to distinguish between the various measurement, cooling-system and blast-furnace setups. Most of the models are already implemented and in operational use. For some of them application at other blast furnaces was already realised or is possible. 9 refs., 18 figs., 20 tab.

  17. Slag-based saltstone formulations

    International Nuclear Information System (INIS)

    Langton, C.A.

    1987-01-01

    Approximately 400 x 10 6 liters of low-level alkaline salt solution will be treated at the Savannah River Plant (SRP) Defense Waste Processing Facility (DWPF) prior to disposal in concrete vaults at SRP. Treatment involves removal of CS + and Sr +2 followed by solidification and stabilization of potential contaminants in saltstone, a hydrated ceramic waste form. Chromium, technetium, and nitrate releases from saltstone can be significantly reduced by substituting hydraulic blast furnace slag for portland cement in the formulation designs. Slag-based mixes are also compatible with Class F fly ash used in saltstone as a functional extender to control heat of hydration and reduce permeability. A monolithic waste form is produced by the hydration of the slag and fly ash. Soluble ion release (NO 3 - ) is controlled by the saltstone microstructure. Chromium and technetium are less leachable from slag mixes compared to cement-based waste forms because these species are chemically reduced to a lower valence state by ferrous iron in the slag and precipitated as relatively insoluble phases, such as CR(OH) 3 and TcO 2 . 5 refs., 4 figs., 4 tabs

  18. Thermal valorisation of automobile shredder residue: injection in blast furnace.

    Science.gov (United States)

    Mirabile, Daphne; Pistelli, Maria Ilaria; Marchesini, Marina; Falciani, Roberta; Chiappelli, Lisa

    2002-01-01

    Wastes with residual heating value, according to the trend of the world legislation, could be thermally reused. The present study is conducted to verify the possibility of thermal valorisation of a waste, denominated fluff, by injection in blast furnace. The fluff, arising from the automobile shredder operations, is a waste characterised by a high organic matrix and is potentially dangerous due to the heavy metals, oils filter and halogenated plastics content. The first step of the work is the chemical, physical and toxicological characterisation of this material. Then the fluff injection in a blast furnace tuyere is theoretically analysed with a mathematical model. Finally, experimental trials are conducted in a pilot plant, simulating the most important part of the blast furnace: the raceway, in order to analyse process and industrial aspects. In view of an industrial application a first economical evaluation is carried out on the basis of model and experimental results.

  19. Radiometric report for a blast furnace tracing with radioactive isotopes

    International Nuclear Information System (INIS)

    Tanase, G.; Tanase, M.

    1995-01-01

    One of the methods to monitor refractory wall of blast furnace is its tracing with radioactive isotopes. The tracer isotope can be detected by two ways: the external dosimetric measurement at the armour of the blast furnace and/or the radiometric measurement of the iron sample charge by charge. Any change in radiometric situation of tracer radioisotope is recorded in a radiometric report. This paper presents an original concept of radiometric report based upon PARADOX and CORELDRAW soft kits. Their advantage are: quick and easy changes, easy recording of current radioactivity of tracer isotope, short history of changes, visual mapping of the tracer isotope and others. In this way we monitored 6 blast furnaces and more than 180 radioactive sources

  20. A Microstructure Based Strength Model for Slag Blended Concrete with Various Curing Temperatures

    Directory of Open Access Journals (Sweden)

    Li-Na Zhang

    2016-01-01

    Full Text Available Ground granulated blast furnace slag, which is a byproduct obtained during steel manufacture, has been widely used for concrete structures in order to reduce carbon dioxide emissions and improve durability. This paper presents a numerical model to evaluate compressive strength development of slag blended concrete at isothermal curing temperatures and time varying curing temperatures. First, the numerical model starts with a cement-slag blended hydration model which simulates both cement hydration and slag reaction. The accelerations of cement hydration and slag reaction at elevated temperatures are modeled by Arrhenius law. Second, the gel-space ratios of hardening concrete are calculated using reaction degrees of cement and slag. Using a modified Powers’ gel-space ratio strength theory, the strength of slag blended concrete is evaluated considering both strengthening factors and weakening factors involved in strength development process. The proposed model is verified using experimental results of strength development of slag blended concrete with different slag contents and different curing temperatures.

  1. A research on ceramsite obtained from blast furnace slag and ...

    African Journals Online (AJOL)

    Jane

    2011-10-05

    Oct 5, 2011 ... This study investigated the feasibility of that at different preheating and sintering temperature ... 2002), lime (Guozhuo et al., 2009), fly ash (Gengying and. Xiaohua, 2003; Halit et al., 2008) to produce ... BFS in this study was obtained from the energy factory of MA. STEEL GROUP, MaAnShan, China. BFS is ...

  2. Granulated blast furnace slag – A boon for foundry industry

    African Journals Online (AJOL)

    Predetermined quantities of sodium silicate and Fe-Si powder were added to the mould ingredients; blending was conducted in a timeframe of five ... were analyzed and same was reported. Figure 2 ... particles with foaming action around it, which can be clearly visible from the obtained SEM images of the moulds under.

  3. Simulation of blast furnace operation during the substitution of coke and pulverized coal with granulated waste plastic

    Directory of Open Access Journals (Sweden)

    Kovačević Tihomir M.

    2014-01-01

    Full Text Available The possibility of using the waste plastic as reducing agent in blast furnace for obtaining pig iron is in focus for the past couple year. The simulation of blast furnace process in BFC software has been performed in order to analyze the coke and coals saving, CO2 emission and determining the economic benefits. Three different batches were made for comparative analysis, depending on the batch composition and input of batch components into the blast furnace: case 1 (C1, case 2 (C2 and case 3 (C3. The base case, C1 contains sinter (bulk material which is needed for obtaining 1 tone of pig iron, quartz which provides slag alkalinity and coke as reducing and energy agent. C2 has the same components as C1, but contains pulverized coal instead one part of coke and C3 contains granulated waste plastic instead coke in an approximately the same amount as pulverized coal. The substitution of coke with pulverized coal and waste plastic is 18.6 % and 25.2 %, respectively. The economic, productivity and ecologic aspects have been analyzed. The consumption of each tone of waste plastic in blast furnace saves 360 $, which is 18 times more than its price, bearing in mind that the market price of coke is 380 $/t % and waste plastic 20 $/t. Regarding the specific productivity, it decreases from 2.13 for C1 to 1.87 for C3. From an environmental aspect there are two main benefits: reduction of CO2 emission and impossibility of dioxin formation. The CO2 emission was 20.18, 19.46 and 17.21 for C1, C2 and C3, respectively.

  4. Immobilization of radioactive waste in cement based matrices

    International Nuclear Information System (INIS)

    Glasser, F.P.; Rahman, A.A.; Macphee, D.; McCulloch, C.E.; Angus, M.J.

    1985-06-01

    The kinetics of reaction between cement and clinoptilolite are elucidated and rate equations containing temperature dependent constants derived for this reaction. Variations in clinoptilolite particle size and their consequences to reactivity are assessed. The presence of pozzolanic agents more reactive than clinoptilolite provides sacrificial agents which are partially effective in lowering the clinoptilolite reactivity. Blast furnace slag-cements have been evaluated and the background literature summarized. Experimental studies of the pore fluid in matured slag-cements show that they provide significantly more immobilization for Cs than Portland cement. The distribution of Sr in cemented waste forms has been examined, and it is shown that most of the chemical immobilization potential in the short term is likely to be associated with the aluminate phases. The chemical and structural nature of these are described. Carbonation studies on real cements are summarized. (author)

  5. Studying and improving blast furnace cast iron quality

    Directory of Open Access Journals (Sweden)

    Т. К. Balgabekov

    2014-10-01

    Full Text Available In the article there are presented the results of studies to improve the quality of blast furnace cast iron. It was established that using fire clay suspension for increasing the mould covering heat conductivity improves significantly pig iron salable condition and filtration refining method decreases iron contamination by nonmetallic inclusions by 50 – 70 %.

  6. High performance concrete with blended cement

    International Nuclear Information System (INIS)

    Biswas, P.P.; Saraswati, S.; Basu, P.C.

    2012-01-01

    Principal objectives of the proposed project are two folds. Firstly, to develop the HPC mix suitable to NPP structures with blended cement, and secondly to study its durability necessary for desired long-term performance. Three grades of concrete to b considered in the proposed projects are M35, M50 and M60 with two types of blended cements, i.e. Portland slag cement (PSC) and Portland pozzolana cement (PPC). Three types of mineral admixtures - silica fume, fly ash and ground granulated blast furnace slag will be used. Concrete mixes with OPc and without any mineral admixture will be considered as reference case. Durability study of these mixes will be carried out

  7. Determination of the coke bed voidage in the blast furnace hearth

    Energy Technology Data Exchange (ETDEWEB)

    Havelange, O.; Danloy, G.; Venturini, M.J. [and others] [CRM, Liege (Belgium)

    2004-07-01

    The objectives of the research were to develop and apply techniques and model tools allowing an online evaluation of the blast furnace hearth conditions and its permeability, in order to guarantee a stable furnace operation and to control the refractory wear through early corrective actions. CRM determined the coke bed voidage in the hearth of BFB of Cockerill-Sambre by two techniques: one based on pressure measurement inside the taphole and the other based on electromotive force measurement. A mathematicalmodel was developed taking into account the movements of the deadman. ln order to continuously determine the hot metal flow rate, BFI measured the filling level in the runner at BF 2 of TKS. A statistical wear model evaluated the cross-sectional runner geometry. The data have been fed into a model to calculate the coke bed voidage on multiple taphole blast furnaces. To control the wear caused by preferential liquid flow, Corus IJmuiden developed a monitoring of temperature and heat flux information from purpose-installed duplex thermocouples. This information has been correlated over time to identify any persistent trends and used to evaluate control measures such as blocked tuyeres and process shutdowns. Industrial trials at Fos BF1 enabled IRSID to propose a picture to describe the effects of the central coke charging practice. IRSID used the Fluent code to describe the liquid flow in the hearth with regard to the deadman conditions and to simulate tracer experiments. From studies of the behaviour of the hearth skull, Corus UK proposed a method for its monitoring. The iron flow rate was measured by using strain gauges attached to the torpedo ladles, and the slag flow rate was estimated from the slag pelletiser current. Data from tuyere core drilling samples were examined to estimate the voidage in the hearth. 38 refs., 127 figs.

  8. Radionuclide content of local and imported cements used in Egypt

    International Nuclear Information System (INIS)

    Mahmoud, K R

    2007-01-01

    The activity concentrations of natural and artificial gamma-ray emitting radionuclides in local and imported cement have been investigated during the period from 2000 to 2003 using a 50% HPGe γ-spectroscopy system. The total numbers of local and imported samples were 29 and 8, respectively. The results showed a low activity concentration of 137 Cs in both the local and imported samples. The only exception was found in one imported Portland cement (2.8 ± 0.2 Bq kg -1 ) and one local blast furnace slag cement (1.9 ± 0.3 Bq kg -1 ). The average activity concentrations of 226 Ra, 232 Th and 40 K in local cement were 33 ± 17, 14 ± 2.4 and 45 ± 26 Bq kg -1 , respectively, whereas those in imported cement were 27 ± 7, 8 ± 7 and 134 ± 22 Bq kg -1 , respectively. The results showed that blast furnace slag cement contains the highest level of natural radioactivity, whereas white cement contains the lowest levels. The measured activity concentrations of the detected radionuclides were compared with other measurements carried out in Egypt and elsewhere. Radium-equivalent activities were also calculated to assess the radiation hazards arising from using such material in the construction of dwellings. Generally, the radium-equivalents of the analysed samples were smaller than the guideline limit of 370 Bq kg -1

  9. Resistance of Alkali Activated Water-Cooled Slag Geopolymer to Sulphate Attack

    Directory of Open Access Journals (Sweden)

    S. A. Hasanein

    2011-06-01

    Full Text Available Ground granulated blast furnace slag is a finely ground, rapidly chilled aluminosilicate melt material that is separated from molten iron in the blast furnace as a by-product. Rapid cooling results in an amorphous or a glassy phase known as GGBFS or water cooled slag (WCS. Alkaline activation of latent hydraulic WCS by sodium hydroxide and/or sodium silicate in different ratios was studied. Curing was performed under 100 % relative humidity and at a temperature of 38°C. The results showed that mixing of both sodium hydroxide and sodium silicate in ratio of 3:3 wt.,% is the optimum one giving better mechanical as well as microstructural characteristics as compared with cement mortar that has various cement content (cement : sand were 1:3 and 1:2. Durability of the water cooled slag in 5 % MgSO4 as revealed by better microstructure and high resistivity-clarifying that activation by 3:3 sodium hydroxide and sodium silicate, respectively is better than using 2 and 6 % of sodium hydroxide.

  10. A Novel Technique for Making Cold Briquettes for Charging in Blast Furnace

    International Nuclear Information System (INIS)

    Mohanty, M K; Mishra, S; Sarkar, S; Samal, S K; Mishra, B

    2016-01-01

    Different metallurgical wastes are generated during pyro processing of iron ore, which is used for making sponge iron or hot metal and for producing steel. Apart from these wastes, coke fines are generated during the coke making, and iron ore fines are generated during mining of iron ore. Although iron ore fines are used for making pellet after beneficiation still, it generates a huge quantity of iron ore waste during beneficiation with comparatively lower iron content. In the present study, briquettes are made by a stiff extrusion process from metallurgical waste like iron ore fines and coke fines with the addition of Portland cement as a binder and clay as a rheology modifier. Physical properties of the briquettes are evaluated, and reducibility of the briquettes is studied in comparison to lumpy iron ore. Phase analysis and microstructural analysis of the briquettes and lumpy iron ore are carried out after firing at different temperatures in the simulated blast furnace condition. Physical and mineralogical properties are correlated with the reducibility of the briquettes and lumpy iron ore. Briquettes made by a stiff extrusion process show a better mechanical strength fired at a different temperature to take the load of burden and better reducibility than lumpy iron ore. The briquettes after self-curing are charged to a 23 mt3 blast furnace which shows encouraging results. (paper)

  11. A Novel Technique for Making Cold Briquettes for Charging in Blast Furnace

    Science.gov (United States)

    Mohanty, M. K.; Mishra, S.; Mishra, B.; Sarkar, S.; Samal, S. K.

    2016-02-01

    Different metallurgical wastes are generated during pyro processing of iron ore, which is used for making sponge iron or hot metal and for producing steel. Apart from these wastes, coke fines are generated during the coke making, and iron ore fines are generated during mining of iron ore. Although iron ore fines are used for making pellet after beneficiation still, it generates a huge quantity of iron ore waste during beneficiation with comparatively lower iron content. In the present study, briquettes are made by a stiff extrusion process from metallurgical waste like iron ore fines and coke fines with the addition of Portland cement as a binder and clay as a rheology modifier. Physical properties of the briquettes are evaluated, and reducibility of the briquettes is studied in comparison to lumpy iron ore. Phase analysis and microstructural analysis of the briquettes and lumpy iron ore are carried out after firing at different temperatures in the simulated blast furnace condition. Physical and mineralogical properties are correlated with the reducibility of the briquettes and lumpy iron ore. Briquettes made by a stiff extrusion process show a better mechanical strength fired at a different temperature to take the load of burden and better reducibility than lumpy iron ore. The briquettes after self-curing are charged to a 23 mt3 blast furnace which shows encouraging results.

  12. Blast furnace coke substitutes from Victorian brown coal

    OpenAIRE

    Mollah, Mamun

    2017-01-01

    Iron is usually produced from its ores using coke in a blast furnace (BF). Coke, a hard and macroporous carbon material, is produced from special coals (coking coals) and acts as fuel, smelting agent, and the permeable support for the charge to the BF. No material can completely replace coke in a BF. Coking coals are becoming harder (and more expensive) to obtain. Victorian brown coal (VBC) is accessible, cheap, with low mineral concentrations, which is favourable for iron production in a BF....

  13. Blasted copper slag as fine aggregate in Portland cement concrete.

    Science.gov (United States)

    Dos Anjos, M A G; Sales, A T C; Andrade, N

    2017-07-01

    The present work focuses on assessing the viability of applying blasted copper slag, produced during abrasive blasting, as fine aggregate for Portland cement concrete manufacturing, resulting in an alternative and safe disposal method. Leaching assays showed no toxicity for this material. Concrete mixtures were produced, with high aggregate replacement ratios, varying from 0% to 100%. Axial compressive strength, diametrical compressive strength, elastic modulus, physical indexes and durability were evaluated. Assays showed a significant improvement in workability, with the increase in substitution of fine aggregate. With 80% of replacement, the concrete presented lower levels of water absorption capacity. Axial compressive strength and diametrical compressive strength decreased, with the increase of residue replacement content. The greatest reductions of compressive strength were found when the replacement was over 40%. For tensile strength by diametrical compression, the greatest reduction occurred for the concrete with 80% of replacement. After the accelerated aging, results of mechanic properties showed a small reduction of the concrete with blasted copper slag performance, when compared with the reference mixture. Results indicated that the blasted copper slag is a technically viable material for application as fine aggregate for concrete mixtures. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Investigations on steel slag re-utilization in developing countries; Hatten tojokoku ni okeru tekko slag sairiyo ni kansuru chosa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    In order to promote steel slag re-utilization in developing countries, a possibility was presented for technical cooperation to India, Indonesia and Thailand upon putting the status of slag utilization in Japan into order. Blast furnace slag produced in Japan (having a re-utilization rate of 95%) is re-utilized and processed as cement aggregates and road beds, and converter slag as civil engineering materials and ores. Steel making slag (having a re-utilization rate of 80%) is re-utilized as road, processing and civil engineering materials. Since the steel making slag faces intensifying competition with ash made by incinerating construction and general wastes, it is important to improve its price competitiveness or mixed utilization with other materials. Re-utilization has not advanced to a recognizable level in developing countries because of having no difficulty for availability of lands for wastes. However, growth of full-scale steel industries and elevation in tendency of environment preservation now urge increase in the slag re-utilization rate. Required to achieve the goal would include wider use of re-utilization technologies, quality control on slag, joint use of facilities to produce re-utilization products, and governmental assistance on burdens of transportation cost. Assistance from Japan is expected to help meet these requirements. 25 figs., 31 tabs.

  15. Experimental evaluation of cement materials for solidifying sodium nitrate

    International Nuclear Information System (INIS)

    Sasaki, Tadashi; Numata, Mamoru; Suzuki, Yasuhiro; Kubo, Yoshikazu

    2003-03-01

    Low-level liquid waste containing sodium nitrate is planned to be transformed to salt block by evaporation with sodium borate in the Low-level Waste Treatment Facility (LWTF), then salt block will be stored temporally. It should be important to investigate the method how to treat these liquid waste suitable to final disposal criteria that will be settled in future. Cement solidification is one of promising candidates because it has been achieved as the solidification material for the shallow land disposal. The research was conducted to evaluate applicability of various cement materials to solidification of sodium nitrate. The following cements were tested. Ordinary Portland Cement (OPC). Portland Blast-furnace Slag Cement; C type (PBFSC). Alkali Activated Slag Cement (AASC, supplied by JGC). The test results are as follows; (1) AASC is characterized by a high sodium nitrate loading (-70 wt%) compared with other types of cement material. High fluidity of the cement paste, high strength after solidification, and minimization of free water on the cement paste are achieved under all test conditions. (2) OOPC and PBFSC produced free water on the cement paste in the early days and delayed the hardening period. 3 or more days are required to harden evan with 30 wt% content of sodium nitrate. (3) Though PBFSC contains blast furnace slag similar to AASC, there is no advantage prior to OPC. To design an ideal cement conditioning system for sodium nitrate liquid waste in the LWTF, the further studies are necessary such as the simulated waste test, Kd test, pilot test, and layout design. (author)

  16. The effect of blast furnace coke quality on the possibility of its use

    Directory of Open Access Journals (Sweden)

    A. Konstanciak

    2013-04-01

    Full Text Available In the paper behavior of the blast-furnace coke in the high temperature was presented. Comparative analysis of the chemical composition of the blast-furnace coke and the heat treatment of it were done. Coefficients M10 and M40 with the thermo-abrasiveness for chosen cokes were compared. The influence of ash content of the coke on the blast-furnace bed permeability was defined. Usefulness of the coke to blast-furnace process was also defined.

  17. Cementation of nitrate solutions by alkali-activated slag-metakaolin cement

    International Nuclear Information System (INIS)

    Rakhimova, N.R.; Rakhimov, R.Z.; Naumkina, N.I.; Gubaidullina, A.M.; Yakovlev, G.I.; Shaybadullina, A.V.

    2015-01-01

    This paper considered the feasibility of solidification of liquid salt wastes by NaNO 3 solutions of concentration 100-700 g/l by alkali-activated slag (AASC) and alkali-activated slag-meta-kaolin cements (AASMC). The AASC (activated by 5% Na 2 O) and AASMC (activated by 5% Na 2 O and introduced with 5% of MK) mixed with NaNO 3 solutions were more effective in comparison with Portland cement. The compressive strength of hardened AASC and AASMC pastes was 1.6-12. and 7- 21 MPa in 3-day age and 13.4-31 and 20-37 MPa in 28-day age, respectively, depending on concentration of NaNO 3 solution. The incorporation of 3-5% meta-kaolin in AASC: (i) increased the compressive strength of hardened AASMC pastes up to 50% depending on the type of meta-kaolin, (ii) shortened setting times of fresh AASMC pastes

  18. Recycling of blast furnace sludge by briquetting with starch binder: Waste gas from thermal treatment utilizable as a fuel.

    Science.gov (United States)

    Drobíková, Klára; Plachá, Daniela; Motyka, Oldřich; Gabor, Roman; Kutláková, Kateřina Mamulová; Vallová, Silvie; Seidlerová, Jana

    2016-02-01

    Steel plants generate significant amounts of wastes such as sludge, slag, and dust. Blast furnace sludge is a fine-grained waste characterized as hazardous and affecting the environment negatively. Briquetting is one of the possible ways of recycling of this waste while the formed briquettes serve as a feed material to the blast furnace. Several binders, both organic and inorganic, had been assessed, however, only the solid product had been analysed. The aim of this study was to assess the possibilities of briquetting using commonly available laundry starch as a binder while evaluating the possible utilization of the waste gas originating from the thermal treatment of the briquettes. Briquettes (100g) were formed with the admixture of starch (UNIPRET) and their mechanical properties were analysed. Consequently, they were subjected to thermal treatment of 900, 1000 and 1100°C with retention period of 40min during which was the waste gas collected and its content analysed using gas chromatography. Dependency of the concentration of the compounds forming the waste gas on the temperature used was determined using Principal component analysis (PCA) and correlation matrix. Starch was found to be a very good binder and reduction agent, it was confirmed that metallic iron was formed during the thermal treatment. Approximately 20l of waste gas was obtained from the treatment of one briquette; main compounds were methane and hydrogen rendering the waste gas utilizable as a fuel while the greatest yield was during the lowest temperatures. Preparation of blast furnace sludge briquettes using starch as a binder and their thermal treatment represents a suitable method for recycling of this type of metallurgical waste. Moreover, the composition of the resulting gas is favourable for its use as a fuel. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Evaluation of the slag attack resistance of high alumina refractory free cement castable

    International Nuclear Information System (INIS)

    Menegazzo, A.P.M.; Pandofelli, V.C.; Rodrigues, J.A.; Carvalho, Julio C.

    1997-01-01

    The slag attack resistance is a very important property when the life time of refractory castable needs to be improved. The substitution of calcium aluminate cement by a free calcium hydraulic blinder has show a viable way to enhance the thermomechanical performance presented by these materials. At the present very few information is found regarding the slag attack of these free cement castable. In this study the slag attack resistance of high alumina castable with and without cement was evaluated by static test. The corroded region was analyzed by SEM and EDS. (author)

  20. Rheological study of self-compacting mortars based on ternary cements

    Directory of Open Access Journals (Sweden)

    Elhadja Dada

    2018-01-01

    Full Text Available Self-compacting concrete (SCC is able to provide the ability to be easily implemented without vibration and to achieve spectacular structures, by its high fluidity and its rheological stability. By against its formulation requires a large volume of cement, which is necessary to allow its flow. The current environmental considerations lead to reduce the production of clinker however, it is essential to use cementitious additions to replace cement, because of their high availability and their moderate price. Furthermore, their use contributes in a simple and economical way to solve the problems related to the environment. The objective of our work is to study the effects of the incorporation of mineral additions such as: blast furnace slag of El-Hadjar (BFS, and marble powder (MP on the rheological parameters of selfcompacting mortars developed in different combinations in ternary system with a substitution rate ranging from 20% to 60%. According to this study, it been found that the substitution of cement by blast furnace slag and marble powder has negatively affected the rheological behavior of the mixtures. In addition, a considerable decrease in the rheological parameters has been achieved with a substitution rate of 20% of slag and 30% of marble powder. As well as an improvement of workability has been proven to self-compacting mortars and this is due to the increase of ternary cement replacement rate by marble powder from 20% to 30%.

  1. Effect of Cement Type on Autogenous Deformation of Cement-Based Materials

    DEFF Research Database (Denmark)

    Pietro, Lura; Ye, Guang; van Breugel, Klaas

    2004-01-01

    In this paper, measurements of non-evaporable water content, chemical shrinkage, autogenous deformation, internal relative humidity (RH), pore solution composition, and early-age elastic modulus are presented and discussed. All experiments were performed on Portland cement and blast-furnace slag...... (BFS) cement pastes. Self-desiccation shrinkage of the BFS cement paste was modeled based on the RH measurements, following the capillary-tension approach. The main findings of this study are: 1) self-desiccation shrinkage can be related to self-desiccation both for Portland and for BFS cement pastes......, taking into account the influence of the dissolved salts in the pore solution, 2) the BFS cement paste studied shows pronounced self-desiccation and self-desiccation shrinkage, mainly caused by its very fine pore structure....

  2. The incorporation of low and medium level radioactive wastes (solids and liquids) in cement

    International Nuclear Information System (INIS)

    Palmer, J.D.; Smith, D.L.G.

    1986-01-01

    The use of cement has been investigated for the immobilization of liquid and solid low and medium level radioactive waste. 220 litre mixing trials have demonstrated that the high temperatures generated during the setting of ordinary Portland cement/simulant waste mixes can be significantly reduced by the use of a blend of ground granulated blast furnace slag and ordinary Portland cement. Laboratory and 220 litre trials using simulant wastes showed that the blended cement gave an improvement in properties of the cemented waste product, e.g. stability and reduction in leach rates compared with ordinary Portland cement formulations. A range of 220 litre scale mixing systems for the incorporation of liquid and solid wastes in cement was investigated. The work has confirmed that cement-based processes can be used for the immobilization of most types of low and medium level waste

  3. R7T7 glass alteration in the presence of mortar: effect of the cement grade

    International Nuclear Information System (INIS)

    Andriambololona, Z.; Godon, N.; Vernaz, E.

    1991-01-01

    R7T7 glass alteration was investigated in the presence of four mortars prepared from four different cement grades: 'CPA' Portland cement (mortar M1), CPA with pozzolana additive (M2), CPA with amorphous silica additive (M3) and 'CLK' blast furnace slag cement (M4). Glass specimens were also altered in Volvic mineral water and in a cement effluent. Glass corrosion in the cement media was greater than in Volvic water, but well below what could be expected from the high pH (approx 12.5). The relatively low alteration was probably related to the protective action of the calcium-enriched gel layer that formed at the glass surface. The glass corrosion rate was 2 to 3 times lower with cement containing pozzolana or silica gel additives or with CLK cement than with CPA cement alone. 8 refs., 8 figs

  4. Electrical properties of alkali-activated slag composite with combined graphite/CNT filler

    Science.gov (United States)

    Rovnaník, P.; Míková, M.; Kusák, I.

    2017-10-01

    Alkali-activated industrial by-products such as blast furnace slag are known to possess properties which are comparable to or even better than those observed for ordinary Portland cement. The combination of alkali-activated slag matrix with conductive filler introduces new functionalities which are commonly known for self-sensing or self-heating concrete. The present paper discusses the effect of the mixture of two different conductive fillers, graphite powder and carbon nanotubes (CNTs), on the electrical properties of alkali-activated slag mortars. Prepared samples were also tested for their mechanical properties and microstructure was investigated by means of mercury intrusion porosimetry and scanning electron microscopy. The percolation threshold for the resistance was reached for the mixture containing 0.1% CNTs and 8% graphite powder.

  5. Immobilization of radioactive waste in cement based matrices

    International Nuclear Information System (INIS)

    Glasser, F.P.; Rahman, A.A.; Macphee, D.; Atkins, M.; Beckley, N.; Lachowski, E.E.

    1986-04-01

    A mathematical and thermodynamic model of the Ca0-Si0 2 -H 2 0 system is presented to enable the solubility and pH relationships in cement and blended cement systems to be predicted. The Esub(h) function has been explored particularly in respect of slag rich systems. The stability of Sr in cements is shown to be influenced by both precipitation and lattice incorporation into the ettringite-like phase. Quality assurance parameters especially for aggregate materials and blast furnace slags are reviewed and recommendations made. It is shown that the latter fluctuate considerably in composition; additional measures for monitoring are recommended and additional research suggested to determine their long-term performance. (author)

  6. Minimization of Blast furnace Fuel Rate by Optimizing Burden and Gas Distribution

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Chenn Zhou

    2012-08-15

    The goal of the research is to improve the competitive edge of steel mills by using the advanced CFD technology to optimize the gas and burden distributions inside a blast furnace for achieving the best gas utilization. A state-of-the-art 3-D CFD model has been developed for simulating the gas distribution inside a blast furnace at given burden conditions, burden distribution and blast parameters. The comprehensive 3-D CFD model has been validated by plant measurement data from an actual blast furnace. Validation of the sub-models is also achieved. The user friendly software package named Blast Furnace Shaft Simulator (BFSS) has been developed to simulate the blast furnace shaft process. The research has significant benefits to the steel industry with high productivity, low energy consumption, and improved environment.

  7. Penetrating waterproofing coatings based on slag -containing cements, modified by natural zeolites

    OpenAIRE

    Пушкарева, Екатерина Константиновна; Суханевич, Марина Владимировна; Бондарь, Екатерина Владимировна

    2014-01-01

    The paper deals with obtaining penetrating waterproofing coatings for concrete surfaces based on the slag-cement systems, modified by natural zeolite additives. The composition was investigated and physico-mechanical properties of slag-containing cements with natural zeolite, which were subsequently modified by the salt-electrolyte complex to create penetrating coating, were optimized. Studying the properties of the developed coating has confirmed its competitiveness in the market of similar ...

  8. An Analysis of the Mechanical Characteristics and Constitutive Relation of Cemented Mercury Slag

    Directory of Open Access Journals (Sweden)

    Xinwei Li

    2017-01-01

    Full Text Available This study focuses on mercury slag in the Tongren area of Guizhou Province, China. Computed tomography (CT is used with uniaxial and triaxial compression tests to examine the mechanical changes in cemented mercury slag and its formation. The CT results for the uniaxial compression test reveal the overall failure process of the mercury slag structure. Based on the coarse-grained soil triaxial test, a modified Duncan-Chang model is compared with the actual monitoring results and is found to be suitable for the analysis of the slag constitutive model.

  9. Effect of demolition/construction wastes on the properties of alkali activated slag cement

    Directory of Open Access Journals (Sweden)

    Sayieda R. Zedan

    2017-12-01

    Full Text Available The key point of this investigation is to study the effect of demolition and building wastes on the physico-chemical and mechanical properties of alkali activated slag (AAS. In this study, ground granulated blast-furnace slag (GGBFS was activated by mixture of 3:3 wt.% sodium hydroxide:liquid sodium silicate (NaOH:Na2SiO3 ratio by weight of GGBFS. AAS was individually replaced by 10 wt.% ceramic, red clay brick and concrete wastes (CW, RCBW and CoW. The results showed that, significant shorter setting times were observed when AAS was replaced by CW, RCBW or CoW. The AAS-CoW showed the shortest setting times compared to other all mixes. The chemically combined water and pH decreased in the direction of AAS-CoW > AAS > AAS-RCBW > AAS-CW. CoW has a positive effect on the compressive strength development at one day of curing, while, CW and RCBW have a negative effect at the same time (1 day. At later ages of curing, the AAS-RCBW showed the highest compressive strength values as compared with AAS-CW, AAS-CoW and AAS. The crystallinity degree of hydration products enhanced when AAS was replaced by these wastes. Also, the Fe2O3 present in waste played an important role on the development of compressive strength. The hydration products were investigated using X-ray diffraction (XRD, Fourier transform infrared (FTIR spectroscopy and scanning electron microscopy (SEM and the results were compared with the development in compressive strength.

  10. Feasibility and economic analysis of solid desiccant wheel used for dehumidification and preheating in blast furnace: A case study of steel plant, Nanjing, China

    International Nuclear Information System (INIS)

    Guan, Yipeng; Zhang, Yufeng; Sheng, Ying; Kong, Xiangrui; Du, Song

    2015-01-01

    To overcome the shortcomings of huge energy consumption from conventional dehumidification using lithium bromide adsorption refrigerating (LBARD) system, a novel desiccant wheel dehumidification and preheating (DWDP) system using two-stage desiccant wheel for blast furnace is brought forward. The DWDP system was designed for dehumidification and preheating in blast furnace of steel plant. It takes waste heat in the slag flushing water as desiccant regeneration and preheating energy. To validate the feasibility of the new DWDP system, experimental studies were conducted based on a steel plant in Nanjing, China. The experiment was designed to use DWDP system in humid outdoor climates e.g. summer seasons. The experimental results indicate that the moisture removal capacity of DWDP system can reach 8.7 g/kg which will lead to the improvement of steel production by 0.9% and the coal is saved of about 2100 tons per year. With the DWDP system, the energy consumed by cooling tower of slag flushing water can decrease 7.3%. All of these energy saved equates to 10.3 million CNY annually. A comparison of initial investment and operating cost between DWDP system and LBRAD system was then carried out. The results show that the initial investment and operating cost of DWDP system is 37% and 57% of present LBARD system, and the payback period is shortened 66%. - Highlights: • A novel two-stage desiccant wheel dehumidification system for blast furnace is proposed. • Average moisture removal of 8.7 g/kg is achieved and dehumidification efficiency is 47%. • Outlet humidity ratio is less than 10 g/kg that satisfies the requirement of blast air. • Waste heat in slag flushing water is utilized and 61.4 million kJ is saved annually. • The investment and operating cost is 37% and 57% of former dehumidification system

  11. Statistical approach to predict compressive strength of high workability slag-cement mortars

    International Nuclear Information System (INIS)

    Memon, N.A.; Memon, N.A.; Sumadi, S.R.

    2009-01-01

    This paper reports an attempt made to develop empirical expressions to estimate/ predict the compressive strength of high workability slag-cement mortars. Experimental data of 54 mix mortars were used. The mortars were prepared with slag as cement replacement of the order of 0, 50 and 60%. The flow (workability) was maintained at 136+-3%. The numerical and statistical analysis was performed by using database computer software Microsoft Office Excel 2003. Three empirical mathematical models were developed to estimate/predict 28 days compressive strength of high workability slag cement-mortars with 0, 50 and 60% slag which predict the values accurate between 97 and 98%. Finally a generalized empirical mathematical model was proposed which can predict 28 days compressive strength of high workability mortars up to degree of accuracy 95%. (author)

  12. Characterization of dust from blast furnace cast house de-dusting.

    Science.gov (United States)

    Lanzerstorfer, Christof

    2017-10-01

    During casting of liquid iron and slag, a considerable amount of dust is emitted into the cast house of a blast furnace (BF). Usually, this dust is extracted via exhaust hoods and subsequently separated from the ventilation air. In most BFs the cast house dust is recycled. In this study a sample of cast house dust was split by air classification into five size fractions, which were then analysed. Micrographs showed that the dominating particle type in all size fractions is that of single spherical-shaped particles. However, some irregular-shaped particles were also found and in the finest size fraction also some agglomerates were present. Almost spherical particles consisted of Fe and O, while highly irregular-shaped particles consisted of C. The most abundant element was Fe, followed by Ca and C. These elements were distributed relatively uniformly in the size fractions. As, Cd, Cu, K, Pb, S, Sb and Zn were enriched significantly in the fine size fractions. Thus, air classification would be an effective method for improved recycling. By separating a small fraction of fines (about 10-20%), a reduction of the mass of Zn in the coarse dust recycled in the range of 40-55% would be possible.

  13. Simulation for the powder movement and accumulation in the lower part of blast furnace

    Energy Technology Data Exchange (ETDEWEB)

    Sugiyama, Takashi [Mineral Resources Research Center, Nippon Steel Technoresearch, Futtsu-shi Chiba (Japan)

    1997-12-31

    The behavior of unburnt char and coke powder in the blast furnace becomes material for discussion with the increase in injection rate of pulverized coal into the blast furnace. An analysis was made as to the simulation of powder accumulation at the deadman and dripping zone of blast furnace by using a powder/gas two-phases flow experimental data. When an excessive powder has penetrated at a low gas velocity, it brings an increment in holdup and the controlling factors are powder/gas ratio and gas velocity. An empirical formula used for estimating the powder hold-up in the blast furnace internal conditions has proposed based on similarity. The controlling {pi} numbers are Floude number, powder/gas ratio and particle diameter ratio of powder/lump. This empirical formular was connected with Blast Furnace Total Model `BRIGHT` for the simulation of powder amount distribution in the lower part of blast furnace. When Powder diameter Dk exceeds 100 {mu} and gas velocity becomes lower than 0.7m/s at PC1OOkg/T, the powder tends to accumulate in the deadman. These results was available for the decision of optimum blast conditions and optimum powder diameter in the high amount of pulverized coal injection to the blast furnace. (author) 10 refs.

  14. Reaction of iron and steel slags with refractories

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, S.; Anderson, M.W. [Magneco/Metrel, Inc., Addison, IL (United States); Singh, J.P.; Poeppel, R.B. [Argonne National Lab., IL (United States)

    1993-04-01

    Slag corrosion and erosion has been a major wear factor for refractories wear in contact with molten iron and steel. In blast furnace ironmaking, the slag/iron interface plays a more important role than does the slag/refractory interface. On the other hand in steelmaking, the slag in the ladles and tundish predominantly affect refractory wear. This paper presents the results of a detailed microstructural evaluation of (a) slag and slag/iron interactions with A1{sub 2}O{sub 3}-SiC-C refractories for ironmaking in blast furnaces, (b) basic oxygen furnace and ladle slag interactions with alumina spinel refractories for steelmaking, and (c) slag interactions with working refractory lining for continuous casting tundishes. Results will also be presented on refractory wear/failure due to simultaneous corrosion and penetration by the slag.

  15. Influence of blast furnace gas flow speed on dust deposition characteristics in butterfly valve region

    Directory of Open Access Journals (Sweden)

    Lixin WANG

    2016-02-01

    Full Text Available The blast furnace gas contains plenty of dust, which deposits easily on the bottom of seat sealing surface of the tri-eccentric butterfly valve in the pipeline, causing stuck and damage to the valve plate, thereby affects the production of the blast furnace and brings great economic loss. To derive the influence mechanism of effects of the blast furnace gas flow speed within the pipeline on the dust deposition laws in the butterfly valve region, a 3D model of the butterfly valve and its regional flow field is built with Pro/E software. Based on FLUENT module of ANSYS Workbench, along with standard k-ε turbulence model and DPM model, simulation analysis of moving trajectories of dust particles in butterfly valve region under 3 blast furnace gas flow speeds is conducted. Results show that the deposition mass of dust particles decreases firstly, then increases with the enlargement of valve plate opening angle under the blast furnace gas flow speed of 8 m/s, while decreases with the enlargement of valve plate opening under the blast furnace gas flow speeds of 12 m/s and 16 m/s. In the case of the valve plate opening angle of 15°, the deposition rate of dust particles increases with the growing of blast furnace gas flow speed, while decreases with the growing of blast furnace gas flow speed under the cases of valve plate opening angle of 45° and 75°. The research results provide a theoretical reference for the development of automatic dust removal system in the butterfly valve region of the blast furnace gas pipeline.

  16. Quantitative study of Portland cement hydration by X-Ray diffraction/Rietveld analysis and geochemical modeling

    Science.gov (United States)

    Coutelot, F.; Seaman, J. C.; Simner, S.

    2017-12-01

    In this study the hydration of Portland cements containing blast-furnace slag and type V fly ash were investigated during cement curing using X-ray diffraction, with geochemical modeling used to calculate the total volume of hydrates. The goal was to evaluate the relationship between the starting component levels and the hydrate assemblages that develop during the curing process. Blast furnace-slag levels of 60, 45 and 30 wt.% were studied in blends containing fly ash and Portland cement. Geochemical modelling described the dissolution of the clinker, and predicted quantitatively the amount of hydrates. In all cases the experiments showed the presence of C-S-H, portlandite and ettringite. The quantities of ettringite, portlandite and the amorphous phases as determined by XRD agreed well with the calculated amounts of these phases after different periods of time. These findings show that changes in the bulk composition of hydrating cements can be described by geochemical models. Such a comparison between experimental and modelled data helps to understand in more detail the active processes occurring during cement hydration.

  17. Alkaline activated slag cements. Determination of reaction degree

    Directory of Open Access Journals (Sweden)

    Fernández-Jiménez, A.

    2001-03-01

    Full Text Available The aim of the present work was to evaluate the validity of non-calorimetric different methods, used in the determination of reaction degree of alkaline activated slag pastes. The methods used were: (a chemical separation by methanol-salicylic acid; (b determination of the weight loss mass between 100-600°C in TG curves, associated to chemically combined water; (c quantification of the -74 ppm signal in 29Si MAS-NMR spectra. The parameters considered in the process were: nature of the alkaline activator (Waterglass, Na2CO3 and NaOH, activator concentration (4% and 3% Na2O in mass with respect to the slag, curing temperature (25 and 45°C, slag specific surface (460 and 900 m2/kg and time of reaction (from 7 days to 18 months. The results obtained indicate that none of the three methods is definitive but complementary and they provide to follow the reactive evolution of the alkaline activated slag cements. The method based on the quantification of the -74 ppm signal in the 29Si MAS NMR is the most suitable method.

    El objetivo del presente trabajo fue evaluar la validez de diferentes métodos, no calorimétricos, utilizados en la determinación del grado de reacción de pastas de escoria activada alcalinamente. Los métodos utilizados fueron: (a método de separación química por disolución en metanol ácido-salicílico; (b determinación de las pérdidas de masa entre 100-600°C en las curvas de TG, pérdidas asociadas a la cantidad de agua químicamente combinada: (c cuantificación de la señal de -74 ppm de los espectros de 29Si RMN MAS. Las variables consideradas en el proceso fueron: naturaleza del activador alcalino (Waterglass, Na2CO3 y NaOH, concentración del activador (4% y 3% de Na2O en masa respecto a la escoria, temperatura de curado (25 y 45°C, superficie específica de la escoria (460 y 900 m2/kg y

  18. Nodal wear model: corrosion in carbon blast furnace hearths

    Directory of Open Access Journals (Sweden)

    Verdeja, L. F.

    2003-06-01

    Full Text Available Criterions developed for the Nodal Wear Model (NWM were applied to estimate the shape of the corrosion profiles that a blast furnace hearth may acquire during its campaign. Taking into account design of the hearth, the boundary conditions, the characteristics of the refractory materials used and the operation conditions of the blast furnace, simulation of wear profiles with central well, mushroom and elephant foot shape were accomplished. The foundations of the NWM are constructed considering that the corrosion of the refractory is a function of the temperature present at each point (node of the liquid metal-refractory interface and the corresponding physical and chemical characteristics of the corrosive fluid.

    Se aplican los criterios del Modelo de Desgaste Nodal (MDN para la estimación de los perfiles de corrosión que podría ir adquiriendo el crisol de un homo alto durante su campaña. Atendiendo al propio diseño del crisol, a las condiciones límites de contorno, a las características del material refractario utilizado y a las condiciones de operación del horno, se consiguen simular perfiles de desgaste con "pozo central", con "forma de seta" ó de "pie de elefante". Los fundamentos del MDN se apoyan en la idea de considerar que la corrosión del refractario es función de la temperatura que el sistema pueda presentar en cada punto (nodo de la intercara refractario-fundido y de las correspondientes características físico-químicas del fluido corrosivo.

  19. Comparison of Hexavalent Chromium Leaching Levels of Zeoliteand Slag-based Concretes

    Science.gov (United States)

    Oravec, Jozef; Eštoková, Adriana

    2017-06-01

    In this experiment, the reference concrete samples containing Portland cement as binder and the concrete samples with the addition of ground granulated blast furnace slag (85% and 95%, respectively as replacement of Portland cement) and other samples containing ground zeolite (8% and 13%, respectively as replacement of Portland cement) were analyzed regarding the leachability of chromium. The prepared concrete samples were subjected to long-term leaching test for 300 days in three different leaching agents (distilled water, rainwater and Britton-Robinson buffer). Subsequently, the concentration of hexavalent chromium in the various leachates spectrophotometrically was measured. The leaching parameters as values of the pH and the conductivity were also studied. This experiment clearly shows the need for the regulation and control of the waste addition to the construction materials and the need for long-term study in relation to the leaching of heavy metals into the environment.

  20. Encapsulation of ILW raffinate in the Dounreay cementation plant

    International Nuclear Information System (INIS)

    Sinclair, G.F.

    1998-01-01

    The Dounreay Cementation Plant has been designed and constructed to encapsulate the first cycle liquid raffinate arising from the reprocessing of irradiated Research Reactor fuel into a cementitious matrix. The acidic liquid waste is conditioned with sodium hydroxide prior to mixing with the cement powders (a 9:1 ratio of Blast Furnace Slag / Ordinary Portland Cement with 5% Lime). The complete cement mixing process is performed within the 500-liter drum, which provides the waste package primary containment. The plant has recently been commissioned and has commenced routine operation, processing stocks of existing raffinate that has been stored at Dounreay for up to 30 years. The waste loading per drum has been optimised within the constraints of the chemical composition of the raffinate, with an expected plant throughput of 2.5 m 3 /week. (author)

  1. Coal-oil mixture combustion program: injection into a blast furnace

    Energy Technology Data Exchange (ETDEWEB)

    Jansto, S.G.; Mertdogan, A.; Marlin, L.A.; Beaucaire, V.D.

    1982-04-30

    A chemically stabilized coal-oil mixture (COM) was made and used as an auxiliary fuel in a blast furnace for 44 days. Approximately 485,000 gallons of COM were produced at an on-site COM plant. Composition was 47.9% coal, 47.6% No. 6 oil, 4.0% water, and 0.5% emulsifier. Average injection rates were 3.8 to 13.0 gpm during different periods of the trial. Coal handling equipment, mixing and processing equipment, pumps, piping, fuel lances, and instrumentation are discussed. The blast furnace performance during the trial is compared to a Base Period of injecting No. 6 oil. Blast furnace performance was satisfactory, with one pound of COM replacing one pound of coke or 0.8 pound of No. 6 oil. The production of COM and its usage in a blast furnace is economical and feasible.

  2. BLAST FURNACE GRANULAR COAL INJECTION SYSTEM. Final Report Volume 2: Project Performance and Economics

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    1999-10-01

    Bethlehem Steel Corporation (BSC) requested financial assistance from the Department of Energy (DOE), for the design, construction and operation of a 2,800-ton-per-day blast furnace granulated coal injection (BFGCI) system for two existing iron-making blast furnaces. The blast furnaces are located at BSC's facilities in Burns Harbor, Indiana. The demonstration project proposal was selected by the DOE and awarded to Bethlehem in November 1990. The design of the project was completed in December 1993 and construction was completed in January 1995. The equipment startup period continued to November 1995 at which time the operating and testing program began. The blast furnace test program with different injected coals was completed in December 1998.

  3. Characterization and modeling of major constituent equilibrium chemistry of a blended cement mortar

    Directory of Open Access Journals (Sweden)

    Meeussen J.C.L.

    2013-07-01

    Full Text Available Cementitious materials containing ground granulated iron blast furnace slag and coal combustion fly ash as admixtures are being used extensively for nuclear waste containment applications. Whereas the solid phases of ordinary Portland cement (OPC have been studied in great detail, the chemistry of cement, fly ash and slag blends has received relatively less study. Given that OPC is generally more reactive than slag and fly ash, the mineralogy of OPC provides a logical starting point for describing the major constituent chemistry of blended cement mortars. To this end, a blended cement mortar containing Portland cement, granulated blast furnace slag, fly ash and quartz sand was modeled using a set of solid phases known to form in hydrated OPC with the geochemical speciation solver LeachXS/ORCHESTRA. Comparison of modeling results to the experimentally determined pH-dependent batch leaching concentrations (USEPA Method 1313 indicates that major constituent concentrations are described reasonably well with the Portland cement mineral set; however, modeled and measured aluminum concentrations differ greatly. Scanning electron microscopic analysis of the mortar reveals the presence of Al-rich phyllosilicate minerals heretofore unreported in similar cementitious blends: kaolinite and potassic phyllosilicates similar in composition to illite and muscovite. Whereas the potassic phyllosilicates are present in the quartz sand aggregate, the formation of kaolinite appears to be authigenic. The inclusion of kaolinite in speciation modeling provides a substantially improved description of the release of Al and therefore, suggests that the behavior of phyllosilicate phases may be important for predicting long-term physico-chemical behavior of such systems.

  4. Influence of thermal charge preparation on coke comminution under blast-furnace operating conditions

    Energy Technology Data Exchange (ETDEWEB)

    Shkoller, M.B.; Dinel' t, V.M.; Korchuganova, G.S.; Petrov, V.B.

    1983-09-01

    Reactions of coke in the blast furnace are determined mainly by the nature of the coke itself which depends on the coal properties, its preparation and the coking conditions. In the blast furnace the coke reacts with alkali and alkaline earth metals in the burden. Preheated coal charges were found to absorb far less sodium and potassium carbonates than a conventional moist charge over an equivalent period, due to the smaller pore volume available.

  5. The design of system for operative planning of blast furnace production process

    Directory of Open Access Journals (Sweden)

    Malindžák Dušan

    1996-12-01

    Full Text Available A system for operative planning of blast furnace production process is described in the paper. The suggested system is based on the use of a new hierarchy of operative plans, consisting of one-month plan, (7+3 days plan, and 24-hour plan. The system allows smoothing of production process at the blast furnace plant, and at the same time satisfies all requirements of the steel plant regarding to the amount of pig iron.

  6. Performance of Cement Containing Laterite as Supplementary Cementing Material

    Directory of Open Access Journals (Sweden)

    Abbas Bukhari, Z. S.

    2013-03-01

    Full Text Available The utilization of different industrial waste, by-products or other materials such as ground granulated blast furnace slag, silica fume, fly ash, limestone, and kiln dust, etc. as supplemen- tary cementing materials has received considerable attention in recent years. A study has been conducted to look into the performance of laterite as Supplementary Cementing Materials (SCM. The study focuses on compressive strength performance of blended cement containing different percentage of laterite. The cement is replaced accordingly with percentage of 2 %, 5 %, 7 % and 10 % by weight. In addition, the effect of use of three chemically different laterites have been studied on physical performance of cement as in setting time, Le-Chatlier expansion, loss on ignition, insoluble residue, free lime and specifically compressive strength of cement cubes tested at the age of 3, 7, and 28 days. The results show that the strength of cement blended with laterite as SCM is enhanced. Key words: Portland cement, supplementary cementing materials (SCM, laterite, compressive strength KUI – 6/2013 Received January 4, 2012 Accepted February 11, 2013

  7. High-Temperatures Rheometric Analysis Of Selected Heterogeneous Slag Systems

    Directory of Open Access Journals (Sweden)

    Migas P.

    2015-06-01

    Full Text Available It is known that the dynamic viscosity coefficient of slag – with an increased titanium compounds content in the reducing conditions of the blast furnace - may rapidly change. The products of the reduction reaction, precipitation and separation of titanium compounds are responsible for the thickening effect of the slag and the problems of permeability of blast furnace, causing anomalies in the dipping zone. The presence of solid components (particles in the melts determines the rheological character of the entire system. Identifying the rheological character of semi-solid slag systems provides opportunities for the development of mathematical modeling of liquid phase flows in a dripping zone of the blast furnace, allowing e.g to indentify the unstable parts of a metallurgical aggregate.

  8. Continuous Microstructural Correlation of Slag/superplasticizer Cement Pastes by Heat and Impedance Methods via Fractal Analysis

    Science.gov (United States)

    Tang, S. W.; Cai, R. J.; He, Z.; Cai, X. H.; Shao, H. Y.; Li, Z. J.; Yang, H. M.; Chen, E.

    This paper presents a preliminary work to evaluate the influence of slag and superplasticizer on the early-age hydration of cement pastes by an innovative non-contact impedance measurement, heat evolution method, compressive strength and setting time tests. Besides, the cumulative pore volume obtained from modulus and phase of impedance in different hydration sections is taken to continuously correlate the cumulative heat releasing of cement pastes via the fractal analysis. Retarded phenomena and mechanism of hydration in cement pastes incorporated with slag and superplasticizer are studied, respectively. It is found that the compressive strength and setting time have a good linear relation with the slag amount in blended cement pastes.

  9. Processing and utilization of metallurgical slag

    Directory of Open Access Journals (Sweden)

    Alena Pribulová

    2016-06-01

    Full Text Available Metallurgy and foundry industry create a huge amount of slags that are by-products in production of pig iron, steel and cast iron. Slag is produced in a very large amount in pyrometallurgical processes, and is a huge source of waste if not properly recycled and utilized. With rapid growth of industrialization, land available for land-filling of large quantity of metallurgical slag is being reduced all over the world and disposal cost is becoming increasingly higher. Metallurgical slag from different metallurgical processes treated and utilized in different ways based on different slag characteristics. The most economic and efficient option for reducing metallurgical waste is through recycling, which is a significant contribution to saving natural resources and reducing CO2 emissions. Characteristic of slags as well as its treatment and utilization are given in the paper. Slag from pig iron and steel production is used most frequently in building industry. From experiments using blast furnace slag and granulated blast furnace slag as gravel, and water glass as binder it can be concluded that that the best results – the best values of compression strength and tensile strength were reached by using of 18% of water glass as a solidification activating agent. According to cubic compression strength, mixture from 50% blast furnace gravel, 50% granulated blast furnace slag and 18% water glass falls into C35/45 class of concrete. Such concrete also fulfils strength requirements for road concrete, moreover, it even exceeds them considerably and, therefore, it can find an application in construction of road communications or in production of concrete slabs.

  10. A theoretical study using the multiphase numerical simulation technique for effective use of H2 as blast furnaces fuel

    Directory of Open Access Journals (Sweden)

    Jose Adilson de Castro

    2017-07-01

    Full Text Available We present a numerical simulation procedure for analyzing hydrogen, oxygen and carbon dioxide gases injections mixed with pulverized coals within the tuyeres of blast furnaces. Effective use of H2 rich gas is highly attractive into the steelmaking blast furnace, considering the possibility of increasing the productivity and decreasing the specific emissions of carbon dioxide becoming the process less intensive in carbon utilization. However, the mixed gas and coal injection is a complex technology since significant changes on the inner temperature and gas flow patterns are expected, beyond to their effects on the chemical reactions and heat exchanges. Focusing on the evaluation of inner furnace status under such complex operation a comprehensive mathematical model has been developed using the multi interaction multiple phase theory. The BF, considered as a multiphase reactor, treats the lump solids (sinter, small coke, pellets, granular coke and iron ores, gas, liquids metal and slag and pulverized coal phases. The governing conservation equations are formulated for momentum, mass, chemical species and energy and simultaneously discretized using the numerical method of finite volumes. We verified the model with a reference operational condition using pulverized coal of 215 kg per ton of hot metal (kg thm−1. Thus, combined injections of varying concentrations of gaseous fuels with H2, O2 and CO2 are simulated with 220 kg thm−1 and 250 kg thm−1 coals injection. Theoretical analysis showed that stable operations conditions could be achieved with productivity increase of 60%. Finally, we demonstrated that the net carbon utilization per ton of hot metal decreased 12%.

  11. Numerical investigation of waste plastic: Injection in a blast furnace

    Energy Technology Data Exchange (ETDEWEB)

    Goto, A.; Morozumi, Y.; Hagiya, H.; Aoki, H.; Miura, T. [Tohoku University, Sendai (Japan). Dept. of Chemical Engineering

    2008-03-15

    In the present study, waste plastic injection in blast furnace processes is investigated numerically. A mathematical model developed in this study describes turbulent flows, heat and mass transfer, chemical reactions in gas, particle and coke-bed phases, and particle trajectories. In the simulation, pulverized particles of coal or plastics are injected into a blowpipe with a nitrogen gas stream, and are then supplied to the raceway region in the coke particle bed. The difference in the gasification behaviors between coal and plastic particles are discussed. The effects of the diameter of plastic particles on the gasification behavior are also investigated. Coal particles are rapidly gasified in the blowpipe because of their small size. In contrast, the gasification of plastic particles rarely occurs in the blowpipe, even if small plastic particles are injected. In addition, the flows of plastic particles are biased in the blowpipe, and consequently the reaction zone of gasification is narrow. In the raceway of the coke bed, the pulverized coal particles exit the raceway due to their small diameter, and are then discharged from the coke bed without sufficient gasification. On the other hand, the plastic particles circulate in the raceway until the diameters thereof decrease below a critical diameter. As a result, since the gasification reaction progresses during the circulation, the combustion efficiency of plastic particles remains high even though the initial diameter of the plastic particles is large.

  12. Injection of heavy fuel oil into the blast furnace

    Energy Technology Data Exchange (ETDEWEB)

    Paloposki, T. [Helsinki Univ. of Technology, Otaniemi (Finland); Hakala, J.; Mannila, P.; Laukkanen, J. [Oulu Univ. (Finland)

    1996-12-31

    This study deals with the injection and combustion of heavy fuel oil in blast furnaces. The injection of the oil was studied experimentally in a small-scale test rig. The combustion of the oil was analysed with a commercial computer program for flow and combustion simulations. Results from computer simulations show that the combustion of the oil can be improved by decreasing the size of the oil drops and by enhancing the mixing between the oil drops and the hot blast. The devolatilization rate of the oil mainly depends on the size of the oil drops. The combustion rate of the volatiles mainly depends on the effectiveness of turbulent mixing with combustion air. Methods to decrease the size of the oil drops were sought in the experimental part of the study. Experimental results show that the size of the oil drops increases with increasing mass flow rate of the oil and decreases with increasing velocity of the hot blast. Methods to improve the mixing between the oil drops and the hot blast are suggested but have not yet been experimentally tested. (author) (4 refs.)

  13. Modelling of turbulent combustion in the blast furnace raceway

    Energy Technology Data Exchange (ETDEWEB)

    Karvinen, R.; Maekiranta, R. [Tampere Univ. (Finland). Energy and Process Engineering

    1996-12-31

    The phenomena concerning coke-gas -suspension and simultaneous combustion of solid coke particles and residual fuel oil in a blast furnace raceway are modelled. The flow field of suspension is predicted by using the two fluid model, which is based on the Eulerian method, in the Phoenics code. The standard k-e -model of turbulence is used. Pyrolysis of oil droplets is calculated with the own coded subroutine, which is based on the Lagrangian approach. Gas phase reaction rate is assumed to be controlled by chemical kinetics. Radiative heat transfer is calculated by using the six-flux method. Heterogenous surface reactions are used for the coke particles. Calculations without coke combustion show that due to a poor mixing in the hot blast, pyrolysis gases of residual fuel oil have not time enough to react with oxygen. It is obvious that if combustion of coke particles is taken into account, the oxygen content in the blast decreases to such a level, that unburnt pyrolysis gases can flow out of the raceway causing problems. The distribution of coke void fraction has been succeeded to predict in the raceway domain. Coke particles fall from the upper part of the raceway to the hot blast forming locally high concentrations, which affect very strongly the oxygen distribution of the hot blast. (orig.) SULA 2 Research Programme; 10 refs.

  14. Recycled materials in Portland cement concrete

    Science.gov (United States)

    2000-06-01

    This report pertains to a comprehensive study involving the use of recycled materials in Portland cement concrete. Three different materials were studied including crushed glass (CG), street sweepings (SS), and recycled concrete (RC). Blast furnace s...

  15. Cementos petroleros con adición de escoria de horno alto. Características y propiedades Characteristics and properties of oil-well cements additioned with blast furnace slag

    OpenAIRE

    Sánchez, R.; Palacios, Marta; Puertas, F.

    2011-01-01

    En el presente trabajo se ha estudiado la activación alcalina de cementos Pórtland con incorporación de escoria de horno alto (20% y 30% con respecto al peso de cemento) para su posible aplicación en la construcción de pozos petrolíferos. Los estudios de hidratación realizados indican que en mezclas cemento/escoria, la disolución activadora de silicato sódico inhibe parcialmente la disolución de las fases silicato del cemento Pórtland originando un retraso de su hidratación así como la m...

  16. Slags in steel making; Kuonat teraeksen valmistuksessa

    Energy Technology Data Exchange (ETDEWEB)

    Haerkki, J.; Paeaetalo, M.; Karhu, P.; Jauhiainen, A.; Alamaeki, P.; Koski-Laine, S.; Ollila, J. [Oulu Univ. (Finland). Dept. of Process Engineering

    1996-12-31

    At the first step of the project all stages of the steelmaking processes were viewed from the blast furnace to the continuous casting. Slag knowledge of each processes were collected into a guide, which is meant to help both production and research. At the same time the essential problems caused by slags in steelmaking were focused. At the second step the focus of this slag-project were transferred into the desulphurization, converter, ladle and tundish slags. Wide slag knowledge has been divided into smaller parts and applied versatile into the steelmaking process taking into account the metallurgical, economical and qualitative aspects. (orig.) SULA 2 Research Programme; 13 refs.

  17. Recovery Act: ArcelorMittal USA Blast Furnace Gas Flare Capture

    Energy Technology Data Exchange (ETDEWEB)

    Seaman, John

    2013-01-14

    The U.S. Department of Energy (DOE) awarded a financial assistance grant under the American Recovery and Reinvestment Act of 2009 (Recovery Act) to ArcelorMittal USA, Inc. (ArcelorMittal) for a project to construct and operate a blast furnace gas recovery boiler and supporting infrastructure at ArcelorMittal’s Indiana Harbor Steel Mill in East Chicago, Indiana. Blast furnace gas (BFG) is a by-product of blast furnaces that is generated when iron ore is reduced with coke to create metallic iron. BFG has a very low heating value, about 1/10th the heating value of natural gas. BFG is commonly used as a boiler fuel; however, before installation of the gas recovery boiler, ArcelorMittal flared 22 percent of the blast furnace gas produced at the No. 7 Blast Furnace at Indiana Harbor. The project uses the previously flared BFG to power a new high efficiency boiler which produces 350,000 pounds of steam per hour. The steam produced is used to drive existing turbines to generate electricity and for other requirements at the facility. The goals of the project included job creation and preservation, reduced energy consumption, reduced energy costs, environmental improvement, and sustainability.

  18. Hot metal temperature prediction and simulation by fuzzy logic in a blast furnace

    International Nuclear Information System (INIS)

    Romero, M. A.; Jimenez, J.; Mochon, J.; Formoso, A.; Bueno, F.; Menendez, J. L.

    2000-01-01

    This work describes the development and further validation of a model devoted to blast furnace hot metal temperature forecast, based on Fuzzy logic principles. The model employs as input variables, the control variables of an actual blast furnace: Blast volume, moisture, coal injection, oxygen addition, etc. and it yields as a result the hot metal temperature with a forecast horizon of forty minutes. As far as the variables used to develop the model have been obtained from data supplied by an actual blast furnaces sensors, it is necessary to properly analyse and handle such data. Especial attention was paid to data temporal correlation, fitting by interpolation the different sampling rates. In the training stage of the model the ANFIS (Adaptive Neuro-Fuzzy Inference System) and the Subtractive Clustering algorithms have been used. (Author) 9 refs

  19. PREPARATION AND PROPERTIES OF ALKALI-ACTIVATED CEMENT CONTAINING PHOSPHOROUS SLAG AND FLY ASH

    Directory of Open Access Journals (Sweden)

    Duo You

    2016-03-01

    Full Text Available Phosphorous slag is an industrial waste which potentially pollutes environments. The aim of the present work is to use phosphorous slag as a raw material to produce alkali-activated cement. The influence of mix proportion of phosphorous slag and fly ash, alkali content and modulus of water glass on the properties of alkali-activated phosphorous slag and fly ash cement (AA-PS-FA-C was studied. The results show that AA-PS-FA-C with normal setting performance and desirable mechanical properties can be prepared using water glass as the activator. Changing the fly ash content in the range of 0-40 wt% has only a small influence on the setting time of AA-PS-FA-C. The strengths significantly decrease when the fly ash content exceeds 30 wt%. The carbonation resistance of AA-PS-FA-C is similar to that of ordinary Portland cement (OPC, while the frost resistance is much better. The hardened paste of AA-PS-FA-C is much more compact than OPC paste.

  20. Evaluation of effectiveness of raw materials and materials use in a blast furnace department of a steelworks

    Directory of Open Access Journals (Sweden)

    E. Kardas

    2017-01-01

    Full Text Available The paper analyses the quality of raw materials used in the production of blast furnace pig iron. The ferruginous sinter and pellets are the basic raw materials used in the process. The paper presents the impact of those raw materials quality on the effectiveness of the blast furnace process. The process effectiveness will be specified by means of selected process parameters.

  1. THE INFLUENCE OF JOINT GRINDING OF CEMENT AND COOPER SLAG ON MORTAR PROPERTIES

    Directory of Open Access Journals (Sweden)

    Kravtsov Aleksey Vladimirovich

    2016-08-01

    Full Text Available The problem of applying copper manufacturing waste locating in the Chelyabinsk region as a component of mixed is considered in this article. Application of mixed binder with superplasticizers, based on esters with carboxyl groups, have not sufficiently been studied by the present time due to the diversity of species and complexity of the chemical structure. This trend is current for today’s science because of the growing rates and scales of building production, in particular, of concrete works. Copper slag dumps located in the Ural Federal district haven’t been widely used in building production or in other industrial production by the present time. Efficient utilization of copper production waste materials will help to solve ecological problems in many regions of Russia. Structure formation period of cement stone based on mixed binder made of Portland cement and granulated cooper slag with application of superplasticizer is studied in the article. The authors present a thermal variation diagram of mortar based on mixed binder made of Portland cement and granulated cooper slag in the process of 21 hours of hardening under normal conditions and the results of ultrasound investigation of concrete structure formation period during 5 hours of hardening. The strength development process diagram of mortar based on mixed binder made of Portland cement and granulated cooper slag for 28 days of hardening under normal conditions and the research results of the compressive strength of concrete samples are shown in this article. The obtained characteristics don’t confirm the prospects of applying joint grinding for mortar with the observed kind of non-ferrous metallurgy waste. Also, the obtained results allow us to make a conclusion about little advantages of using this method of binder production. Copper slag can be more effectively used as a component of complex organic and mineral admixture for building production with different purposes and fields

  2. Competição entre materiais corretivos (escórias de siderurgia x calcário em solos de várzea do Vale do Paraíba Utilization of two types of blast furnace slag as a soil corrective in the Paraíba Valley

    Directory of Open Access Journals (Sweden)

    A. Gentil Gomes

    1962-01-01

    Full Text Available Embora apresentando os solos do Vale do Rio Paraíba, com poucas exceções, acidez de média a elevada, muito pouco uso de corretivos de solos tem sido feito. Êste fato se deve principalmente ao pequeno número de jazidas de calcário existente na região, insuficiente para atender à demanda desse material para a agricultura. Visando colaborar na solução do problema, foram estudadas em seis experimentos instalados em solos de várzea, as possibilidades de utilização de dois tipos de escórias, provenientes da Usina Siderúrgica Nacional de Volta Redonda e da produção de aço em São Caetano e Moji das Cruzes. Nesses ensaios, em culturas de batata e tomate, foram comparados os dois tipos de escórias e um de calcário, em três níveis, tendo como testemunha um tratamento que recebeu apenas a adubação básica, NPK. Os resultados obtidos autorizam a recomendação do emprêgo das escorias. Para sua comercialização, entretanto, necessário se torna alterar o grau de moagem, para que sua granulometria satisfaça às exigências legais.Although the soil in the Paraiba Valley generally presents medium to high acidity, the practice of liming is not yet widespread there. One of the reasons for this is the lack of enough lime sources in its vicinity. As a contribution to the study of the liming problem in the Paraiba Valley, six experiments were carried out on various types of soils in the area, comparing two types of slags with limestone as soil correctives. The slags were obtained from the Usina Siderúrgica Nacional, Volta Redonda and from the São Caetano Steel Plant, São Caetano. They were conducted with the tomato and potato crops. Three levels of each type of slag or limestone, plus a complete fertilizer, were compared. Control plots received only the fertilizer. The results from these experiments indicated that the two types of slag compared favorably with limestone as a calcium source. Both can be recommended as a corrective for

  3. Reduction disintegration mechanism of cold briquettes from blast furnace dust and sludge

    Directory of Open Access Journals (Sweden)

    Leandro Rocha Lemos

    2015-07-01

    Full Text Available It is important to understand the reduction disintegration mechanism in ferriferous burden that is used in blast furnaces. The behavior of this burden in the granular zone of this metallurgical reactor is important for smooth operation. The objective of this work was to prepare cold self-reducing briquettes using blast furnace dust and sludge and binders and compare the reduction disintegration index (RDI of these agglomerates with conventional ferriferous burdens such as pellets, sinter and iron ore. In the present work, 25 different mixtures were prepared to produce briquettes in two geometries: pillow and cylindrical. The RDI value was determined for the briquettes that passed the tumbling test.

  4. Comparison of CO2 emission between COREX and blast furnace iron-making system.

    Science.gov (United States)

    Hu, Changqing; Han, Xiaowei; Li, Zhihong; Zhang, Chunxia

    2009-01-01

    Steel works faced increasing demand to minimize the emission of GHGs. The CO2 emissions of COREX and blast furnace iron-making system were compared. It is point out that COREX contribute little to CO2 emission reduction. Comparing to conventional blast furnace iron-making system, direct CO2 emissions of COREX is higher. Considering the credits of export gases for power generation, the total CO2 emission of COREX have advantages only when the COREX is joined with high-efficiency generating units which efficiency is greater than 45% and CO2 emission factor of the grid is higher than 0.9 kgCO2/kWh.

  5. The effect of soaking time on properties of blast furnace coke

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, R.; Dash, P.S.; Krishnan, S.H.; Kumar, D. [Tata Steel, Jamshedpur (India)

    2004-07-01

    Attempts were made to study the effect of soaking time on properties of blast furnace coke at Tata Steel. Plant trial indicated that when soaking time was increased the +50 mm size coke, mean size, and M{sub 40} indices improved. The CSR value exhibited no significant improvement after a certain limit. This may be due to stability of coke structure improvement in coke quality by increasing soaking time. To achieve the maximum improvement in coke cost, loss of output and heat consumption may be compensated by decreasing coke rate and improving productivity in the blast furnace. 6 refs., 8 figs., 3 tabs.

  6. Production analysis of methanol and hydrogen of a modificated blast furnace gas using nuclear energy of the high temperature reactor

    International Nuclear Information System (INIS)

    Peschel, W.

    1985-12-01

    Modern blast furnaces are operated with a coke ration of 500 kg/t pig iron. The increase of the coke ratio to 1000 kg/t pig iron raises the content of carbon monoxide and hydrogen in the blast furnace gas. On the basis of a blast furnace gas modificated in such a way, the production of methanol and hydrogen is investigated under the coupling of current and process heat from the high temperature reactor. Moreover the different variants are discussed, for which respectively a material and energetic balance as well as an estimation of the production costs is performed. Regarding the subsequent treatment of the blast furnace gas it turns out favourably in principle to operate the blast furnace with a nitrogen-free wind consisting only of oxygen and steam. The production costs show a strong dependence on the raw material costs, whose influence is shown in a nomograph. (orig.) [de

  7. Polymer-Cement Composites Containing Waste Perlite Powder

    Directory of Open Access Journals (Sweden)

    Paweł Łukowski

    2016-10-01

    Full Text Available Polymer-cement composites (PCCs are materials in which the polymer and mineral binder create an interpenetrating network and co-operate, significantly improving the performance of the material. On the other hand, the need for the utilization of waste materials is a demand of sustainable construction. Various mineral powders, such as fly ash or blast-furnace slag, are successfully used for the production of cement and concrete. This paper deals with the use of perlite powder, which is a burdensome waste from the process of thermal expansion of the raw perlite, as a component of PCCs. The results of the testing of the mechanical properties of the composite and some microscopic observations are presented, indicating that there is a possibility to rationally and efficiently utilize waste perlite powder as a component of the PCC. This would lead to creating a new type of building material that successfully meets the requirements of sustainable construction.

  8. Immobilization of antimony waste slag by applying geopolymerization and stabilization/solidification technologies.

    Science.gov (United States)

    Salihoglu, Güray

    2014-11-01

    During the processing of antimony ore by pyrometallurgical methods, a considerable amount of slag is formed. This antimony waste slag is listed by the European Union as absolutely hazardous waste with a European Waste Catalogue code of 10 08 08. Since the levels of antimony and arsenic in the leachate of the antimony waste slag are generally higher than the landfilling limits, it is necessary to treat the slag before landfilling. In this study, stabilization/solidification and geopolymerization technologies were both applied in order to limit the leaching potential of antimony and arsenic. Different combinations ofpastes by using Portland cement, fly ash, clay, gypsum, and blast furnace slag were prepared as stabilization/solidification or geopoljymer matrixes. Sodium silicate-sodium hydroxide solution and sodium hydroxide solution at 8 M were used as activators for geopolymer samples. Efficiencies of the combinations were evaluated in terms of leaching and unconfined compressive strength. None of the geopolymer samples prepared with the activators yielded arsenic and antimony leaching below the regulatory limit at the same time, although they yielded high unconfined compressive strength levels. On the other hand, the stabilization/solidification samples prepared by using water showed low leaching results meeting the landfilling criteria. Use of gypsum as an additive was found to be successful in immobilizing the arsenic and antimony.

  9. Effect of Admixtures on the Yield Stresses of Cement Pastes under High Hydrostatic Pressures.

    Science.gov (United States)

    Yim, Hong Jae; Kim, Jae Hong; Kwon, Seung Hee

    2016-03-02

    When cement-based materials are transported at a construction site, they undergo high pressures during the pumping process. The rheological properties of the materials under such high pressures are unknown, and estimating the workability of the materials after pumping is a complex problem. Among various influential factors on the rheology of concrete, this study investigated the effect of mineral and chemical admixtures on the high-pressure rheology. A rheometer was fabricated that could measure the rheological properties while maintaining a high pressure to simulate the pumping process. The effects of superplasticizer, silica fume, nanoclay, fly ash, or ground granulated blast furnace slag were investigated when mixed with two control cement pastes. The water-to-cement ratios were 0.35 and 0.50.

  10. Effect of Admixtures on the Yield Stresses of Cement Pastes under High Hydrostatic Pressures

    Directory of Open Access Journals (Sweden)

    Hong Jae Yim

    2016-03-01

    Full Text Available When cement-based materials are transported at a construction site, they undergo high pressures during the pumping process. The rheological properties of the materials under such high pressures are unknown, and estimating the workability of the materials after pumping is a complex problem. Among various influential factors on the rheology of concrete, this study investigated the effect of mineral and chemical admixtures on the high-pressure rheology. A rheometer was fabricated that could measure the rheological properties while maintaining a high pressure to simulate the pumping process. The effects of superplasticizer, silica fume, nanoclay, fly ash, or ground granulated blast furnace slag were investigated when mixed with two control cement pastes. The water-to-cement ratios were 0.35 and 0.50.

  11. A novel method to produce dry geopolymer cement powder

    Directory of Open Access Journals (Sweden)

    H.A. Abdel-Gawwad

    2016-04-01

    Full Text Available Geopolymer cement is the result of reaction of two materials containing aluminosilicate and concentrated alkaline solution to produce an inorganic polymer binder. The alkali solutions are corrosive and often viscous solutions which are not user friendly, and would be difficult to use for bulk production. This work aims to produce one-mix geopolymer mixed water that could be an alternative to Portland cement by blending with dry activator. Sodium hydroxide (SH was dissolved in water and added to calcium carbonate (CC then dried at 80 °C for 8 h followed by pulverization to a fixed particle size to produce the dry activator consisting of calcium hydroxide (CH, sodium carbonate (SC and pirssonite (P. This increases their commercial availability. The dry activator was blended with granulated blast-furnace slag (GBFS to produce geopolymer cement powder and by addition of water; the geopolymerization process is started. The effect of W/C and SH/CC ratio on the physico-mechanical properties of slag pastes was studied. The results showed that the optimum percent of activator and CC content is 4% SH and 5% CC, by the weight of slag, which give the highest physico-mechanical properties of GBFS. The characterization of the activated slag pastes was carried out using TGA, DTG, IR spectroscopy and SEM techniques.

  12. Sodium Silicate Gel Effect on Cemented Tailing Backfill That Contains Lead-Zinc Smelting Slag at Early Ages

    OpenAIRE

    Guo, Lijie; Li, Wenchen; Yang, Xiaocong; Xu, Wenyuan

    2018-01-01

    This paper presents the results of an experimental study on the priming effect of sodium silicate gel (SS) on cemented tailing backfill (CTB) that contains lead-zinc smelting slag. CTB and cemented paste (CP) containing lead-zinc smelting slag samples with SS of 0 and 0.4% of the mass of the slag were prepared and cured at 20°C for 1, 3, 7, and 28 days. Mechanical test and pore structure analyses were performed on the studied CTB samples, microstructural analyses (X-ray diffraction analysis a...

  13. Radiological impact of cement, concrete and admixtures in Spain

    International Nuclear Information System (INIS)

    Chinchon-Paya, S.; Piedecausa, B.; Hurtado, S.; Sanjuan, M.A.; Chinchon, S.

    2011-01-01

    It has been analyzed samples of portland cement (PC) with and without admixtures, samples of calcium aluminate cement (CAC) with different content of Al 2 O 3 and specimens of concrete made with PC and CAC using High Resolution Gamma Spectrometry. The activity concentration index (I) is much less than 0.5 mSv y -1 for all the concrete specimens according to the Radiation protection document 112 of the European Commission. The PC without admixtures (CEM I 52,5 R) and the PC with addition of limestone (CEM II/BL 32,5 N) also have an I value much lower than 0.5 and the PC with the addition of fly ash and blast furnace slag (CEM IV/B (V) 32,5 N and III/A 42.5 N/SR) have an I value close to 0.6. The I value of the CAC used in the manufacture of structural precast concrete is of the order of 1 mSv y -1 . Some of the CAC used in refractory concrete reaches a value close to 2 mSv y -1 . - Highlights: → The activity values (I) of spanish portland cement and admixtures studied are similar to those described by other authors. → For the first time in scientific publications we have shown results of several calcium aluminate cements (CAC). → CAC used in structural concrete has an approximate I value = 1 (similar to blast furnace slag and fly ash). → One type of CAC with Al 2 O 3 content of 51% used in refractory concretes has a value of I = 2.

  14. Formulation of geopolymer cement using mixture of slag and class f fly ash for oil well cementing

    Science.gov (United States)

    Kanesan, Dinesh; Ridha, Syahrir; Rao, Prasath

    2017-05-01

    The increase in greenhouse gas emissions has been a factor for the increase in global temperature. Geopolymer cement has been intensively studied to replace conventional ordinary Portland cement, however the focus is limited to civil purposes under atmospheric conditions. This research focuses on the formulation of geopolymer cement to be used in oil well cementing application by taking account the effect of sodium hydroxide (NaoH) molarity, ratio of alkali binder and fly ash, amount of dispersant for oilwell operation under temperature ranging of 80°C and 90C° and pressure of 1000 and 3000psi. The formulated composition is tested for fluid loss where the standard has been from 60 to 80 ml. The cement slurry is cured in a 50mm x 50mm x 50mm mold for period of 24 hours. Four manipulating variables were set in formulating the cement slurry namely, the ratio between fly ash and slag to alkali binder, ratio of sodium hydroxide (NaoH) to sodium silicate, molarity of NaoH and amount of dispersant added. After running a set of 16 experiment, sample (12) was found to possess the best rheological properties and fluid loss according to API RP10B. It was found that as the curing temperature and pressure increase, the compressive strength of the formulated geopolymer cement also increased.

  15. Effect of nut coke on the performance of the ironmaking blast furnace

    NARCIS (Netherlands)

    Song, Q.

    2013-01-01

    The blast furnace consumes a large amount of high quality metallurgy coke (size 35-80 mm) in addition to ore in the form of pellets and sinter. This coke is the coarse fraction, derived from the coke plant. The fine fraction (8 -35 mm), arise after sieving, named nut coke, can’t be directly used in

  16. Improvement in blast furnace reaction efficiency through the use of highly reactive calcium rich coke

    Energy Technology Data Exchange (ETDEWEB)

    Nomura, S.; Ayukawa, H.; Kitaguchi, H.; Tahara, T.; Matsuzaki, S.; Naito, M.; Koizumi, S.; Ogata, Y.; Nakayama, T.; Abe, T. [Nippon Steel Corp. Ltd., Chiba (Japan)

    2005-07-01

    A method to produce coke in 'lump' form with high strength and reactivity through the addition of a catalyst was investigated in order to improve blast furnace reaction efficiency. The addition of Ca compounds to coal before carbonization was found to considerably increase the reactivity of the coke at a low temperature range in the thermal reserve zone of a blast furnace. Furthermore it was proved that strong, highly reactive 'lump' form coke could be produced by adding a Ca-rich non-caking coal and adjusting the coal blend composition. Based on this fundamental study, the Ca-rich coke was successfully produced in coke ovens on a commercial scale, both at Kimitsu and Muroran works. The use of the Ca-rich coke in the Muroran No. 2 blast furnace was found to cause a decrease in the reducing agent rate by 10kg/t-p. This technology, producing coke of high reactivity and strength through catalyst addition, is promising as a means of improving the reaction efficiency of a blast furnace.

  17. Improvement in blast furnace reaction efficiency through the use of highly reactive calcium rich coke

    Energy Technology Data Exchange (ETDEWEB)

    Nomura, S.; Ayukawa, H.; Kitaguchi, H.; Tahara, T.; Matsuzaki, S.; Naito, M.; Koizumi, S.; Ogata, Y.; Nakayama, T.; Abe, T. [Nippon Steel Corporation Ltd, Futtsu (Japan). Environmental & Processing Technology Centre

    2006-03-15

    A method to produce coke in 'lump' form with high strength and reactivity through the addition of a catalyst was investigated in order to improve blast furnace reaction efficiency. The addition of Ca compounds to coal before carbonization was found to considerably increase the reactivity of the coke at a low temperature range equivalent to the thermal reserve zone temperature of a blast furnace. Furthermore it was proved that strong, highly reactive 'lump' form coke could be produced by adding a Ca-rich non-caking coal and adjusting the coal blend composition. Based on this fundamental study, the Ca-rich coke was successfully produced in coke ovens on a commercial scale, both at Kimitsu and Muroran works. The use of the Ca-rich coke in the Muroran No. 2 blast furnace was found to cause a decrease in the reducing agent rate by 10 kg/t-p. This technology, producing coke of high reactivity and strength through catalyst addition, is promising as a means of improving the reaction efficiency of a blast furnace.

  18. Solidification of nitrate solutions with alkali-activated slag and slag–metakaolin cements

    Energy Technology Data Exchange (ETDEWEB)

    Rakhimova, Nailia R., E-mail: rahimova.07@list.ru [Kazan State University of Architecture and Engineering, Kazan (Russian Federation); Rakhimov, Ravil Z. [Kazan State University of Architecture and Engineering, Kazan (Russian Federation); Osin, Yury N. [Kazan Federal University, Kazan (Russian Federation); Naumkina, Natalia I.; Gubaidullina, Alfiya M. [Central Research Institute for Geology of Industrial Minerals, Kazan (Russian Federation); Yakovlev, Grigory I.; Shaybadullina, Arina V. [Kalashnikov Izhevsk State Technical University, Izhevsk (Russian Federation)

    2015-02-15

    Highlights: • The effectiveness of an AASC matrix for NaNO{sub 3} solution solidification is stated. • XRD, DTA-TG, and X-ray microtomography experiments were performed. • Crystallization of NaNO{sub 3} reduces the shrinkage of hardened AASC-based waste forms. • Metakaolin shortens the setting time and increases the compressive strength of AASC. - Abstract: The solidification of nitrate solutions with alkali-activated slag (AASC) and slag–metakaolin cements (AASMC) and the resulting setting times, compressive strengths, dimensional stability, water resistance, hydration products, microstructures, and macroporous network structures were evaluated. The influences of the alkali activator concentration, mineral composition of metakaolin, ratio of slag to slag + metakaolin, and concentration of NaNO{sub 3} on the cement performance were all evaluated in detail. The compressive strength of cemented nitrate solutions with AASC and AASMC aged for 28 days was from 13.4 to 42 MPa depending on the NaNO{sub 3} concentration. X-ray diffractometer, differential thermal analyzer, and electron microscope analyses suggested that NaNO{sub 3} crystallizes in cementitious matrices without reacting with the hydration products of AASC and AASMC. X-ray microtomography showed that the solidified NaNO{sub 3} solution with a salt concentration of 700 g/l and AASC had a denser microstructure without shrinkage microcracks, a smaller macropore volume, and smaller macropore sizes than hardened AASC-based paste mixed with water.

  19. Solidification of nitrate solutions with alkali-activated slag and slag–metakaolin cements

    International Nuclear Information System (INIS)

    Rakhimova, Nailia R.; Rakhimov, Ravil Z.; Osin, Yury N.; Naumkina, Natalia I.; Gubaidullina, Alfiya M.; Yakovlev, Grigory I.; Shaybadullina, Arina V.

    2015-01-01

    Highlights: • The effectiveness of an AASC matrix for NaNO 3 solution solidification is stated. • XRD, DTA-TG, and X-ray microtomography experiments were performed. • Crystallization of NaNO 3 reduces the shrinkage of hardened AASC-based waste forms. • Metakaolin shortens the setting time and increases the compressive strength of AASC. - Abstract: The solidification of nitrate solutions with alkali-activated slag (AASC) and slag–metakaolin cements (AASMC) and the resulting setting times, compressive strengths, dimensional stability, water resistance, hydration products, microstructures, and macroporous network structures were evaluated. The influences of the alkali activator concentration, mineral composition of metakaolin, ratio of slag to slag + metakaolin, and concentration of NaNO 3 on the cement performance were all evaluated in detail. The compressive strength of cemented nitrate solutions with AASC and AASMC aged for 28 days was from 13.4 to 42 MPa depending on the NaNO 3 concentration. X-ray diffractometer, differential thermal analyzer, and electron microscope analyses suggested that NaNO 3 crystallizes in cementitious matrices without reacting with the hydration products of AASC and AASMC. X-ray microtomography showed that the solidified NaNO 3 solution with a salt concentration of 700 g/l and AASC had a denser microstructure without shrinkage microcracks, a smaller macropore volume, and smaller macropore sizes than hardened AASC-based paste mixed with water

  20. Microstructural evolution of cemented paste backfill: Mercury intrusion porosimetry test results

    Energy Technology Data Exchange (ETDEWEB)

    Serge Ouellet; Bruno Bussiere; Michel Aubertin; Mostafa Benzaazoua [Universite du Quebec en Abitibi-Temiscamingue, Rouyn-Noranda, PQ (Canada)

    2007-12-15

    The microstructural evolution of different cemented paste backfill (CPB) samples made with ground silica was evaluated using mercury intrusion porosimetry (MIP). The influence of three binders (OPC, OPC with fly ash, and OPC with blast furnace slag) and of three types of water (one deionised and two sulphated) on the microstructure was studied over the curing time. Uniaxial compressive strength (UCS) tests were also performed to relate MIP results to the backfill mechanical strength. Among other findings, the MIP analyses indicate that the slag based binder combined with a mixing water having a high sulphate content (of 7549 ppm) showed the highest percentage of fine pores and the highest strength. This behaviour is related to the potential precipitation of sulphate phases in pores, which may contribute to strength enhancement. Based on MIP pore size distributions and UCS results, the authors propose a general relationship applicable for CPB.

  1. The use of the bottom ashes and of the steelmaking slags in the manufacturing technologies of the building materials

    Directory of Open Access Journals (Sweden)

    L. G. Popescu

    2016-07-01

    Full Text Available The energetic and metallurgy industries of Romania represent the main waste sources significant from the point of quantitative view: the bottom ashes and the blast furnace and secondary metallurgical slags. Starting from the knowledge of the main chemical-physical properties of these two types of industrial wastes, there were inquired the exploitation possibilities in the technological practice, by using in the manufacturing of some building materials, for which these wastes represent the exclusive raw material source. The experiments considered the granular aggregate properties of the bottom ash and of the blast furnace slag, completed by the hydraulic binder of the secondary metallurgical slag, after the fine crushing.

  2. A Feasibility Study for Recycling Used Automotive Oil Filters In A Blast Furnace

    Energy Technology Data Exchange (ETDEWEB)

    Ralph M. Smailer; Gregory L. Dressel; Jennifer Hsu Hill

    2002-01-21

    This feasibility study has indicated that of the approximately 120,000 tons of steel available to be recycled from used oil filters (UOF's), a maximum blast furnace charge of 2% of the burden may be anticipated for short term use of a few months. The oil contained in the most readily processed UOF's being properly hot drained and crushed is approximately 12% to 14% by weight. This oil will be pyrolized at a rate of 98% resulting in additional fuel gas of 68% and a condensable hydrocarbon fraction of 30%, with the remaining 2% resulting as carbon being added into the burden. Based upon the writer's collected information and assessment, there appears to be no operational problems relating to the recycling of UOF's to the blast furnace. One steel plant in the US has been routinely charging UOF's at about 100 tons to 200 tons per month for many years. Extensive analysis and calculations appear to indicate no toxic consideration as a result of the pyrolysis of the small contained oil ( in the 'prepared' UOFs) within the blast furnace. However, a hydrocarbon condensate in the ''gasoline'' fraction will condense in the blast furnace scrubber water and may require additional processing the water treatment system to remove benzene and toluene from the condensate. Used oil filters represent an additional source of high quality iron units that may be effectively added to the charge of a blast furnace for beneficial value to the operator and to the removal of this resource from landfills.

  3. EVALUATION OF CEMENT THIXOTROPY FOR THE CEMENT OF OIL WELLS IN AREAS WITH LOSSES: EFFECT OF PLASTER AND DAIRY OF HIGH FURNACES

    Directory of Open Access Journals (Sweden)

    T. Bouziani

    2010-12-01

    Full Text Available Cementing of oil and gas wells can be a very delicate operation. Among the concerns of service companies, during this operation are the nature and conditions of the formations in well. This is the case of cementing operations in southern Algeria, specifically on the fields of In-Amen, where the formations in lost zones are naturally weak and highly permeable. In these areas, drilling fluids (muds and cements pumped will be, completely or partially lost, what we call "lost circulation". Thixotropic cements are useful to overcome lost circulation problems. They are characterized by a special rheological behavior, allowing it to plug lost zones when they are pumped. Our work aims to assess the thixotropy of cements perapred with two types of cement (class G Asland cement and CEM I 42.5 portland cement with the plaster, using a viscometer with coaxial cylinder (couette type. Moreover, the effect of blast furnace slag (LHF on the properties and thixotropic mixtures prepared was also studied. The results show that portland cement (available locally can produce mixes with higher and more stable thixotropy than the class G cement (from importation, which is a practical and economical for cementing job operations in wells with loss zones. The results also show that the effect of LHF is positive, since in addition to his contribution to long term performances, especially the durability of hardened concrete, it improves the thixotropy of cement made of plaster.

  4. Influence of Mechanically Activated Electric Arc Furnace Slag on Compressive Strength of Mortars Incorporating Curing Moisture and Temperature Effects

    Directory of Open Access Journals (Sweden)

    Muhammad Nasir Amin

    2017-07-01

    Full Text Available In this study, the influence of mechanically activated electric arc furnace slag (EAFS was investigated through compressive strength tests on 50 mm mortar cubes. The objective was to convert the wasteful EAFS into a useful binding material to reduce the cement content in concrete without compromising strength and economy. Four different groups of mortar were cast which include control mortar, reference fly ash mortar, mortar containing EAFS to determine its optimum fineness and replacement with cement, mortar blend containing fly ash and EAFS of optimum fineness. EAFS were identified with respect to its fineness as slag ground (SG, slag-fine (SF 100% passing 75 µm sieve, and slag-super-fine (SSF 100% passing 45 µm sieve. Compressive strength was measured according to ASTM C109. Specimens were cured under different temperatures and moisture to incorporate the effects of normal and hot environmental conditions. Compressive strength of mortars increases with fineness of EAFS and its strength activity index matches the ASTM C989 blast furnace slag (BFS Grade 80 up to 30% cement substitution and Grade 100 when 10% cement substituted with SSF. The influence of curing temperatures was also significant in mortars containing SG or 10% SF where strength decreased with increasing curing temperature. However, a 20–30% and 20% cement substitution with SF produced strength comparable to control and reference fly ash mortars under moderate (40 °C and high curing temperature (60 °C, respectively. The utilization of EAFS as binder in concrete may reduce needs for cement, as well as save environment and natural resources from depletion.

  5. Research on the use of Ferro-Chrome slag in civil engineering applications

    Directory of Open Access Journals (Sweden)

    Al-Jabri Khalifa S.

    2018-01-01

    Full Text Available Over recent decades there has been rapid increase in the industrial waste materials and by-products yields due to the progressive growth rate of population, development of industry and technology and the growth of consumerism. With the growing environmental pressures to reduce waste and pollution, Intensive research studies have been conducted to explore all suitable reuse methods. Wastes such as construction waste, blast furnace, steel slag, coal fly ash and bottom ash have been approved in many places as alternative materials in bridges, roads, pavements, foundations and building construction. The use of industrial solid waste as a partial replacement of raw materials in construction activities not only saves landfill space but also reduces the demand for extraction of natural raw materials. Ferrochrome slag is a by-product from the production of chrome. There are environmental and economic advantages in seeing slags as a potentially useful resource rather than as waste products. Slag management at ferrochrome producing companies has been influenced by the limited space available and financial cost implications of the slag dumps. Internationally, e.g. South Africa, India, Norway, Turkey, East Europe, China, Sweden and USA, ferrochrome slag is used commercially in the road and construction Industries. This material is being used for road construction, as aggregates in concrete industry, brick manufacturing, and in pavement construction as engineering fill and has recently been tried in cement. This paper presents an overview of the recent advances of the use of ferrochrome slag in various civil engineering applications such as road construction, and cement and concrete industries.

  6. Thermophysical properties of blends from Portland and sulfoaluminate-belite cements

    International Nuclear Information System (INIS)

    Mojumdar, S.C.; Janotka, I.

    2002-01-01

    The behavior of mortars with blends consisting of sulfoaluminate-belite cements and ordinary Portland cement made with cement to sand ratio of 1:3 by weight and w/c = 0.5 maintained for 90 days at 20 0 C either at 60% relative humidity - dry air or 100% relative humidity - wet air. The results show insufficient character of hydraulic activity of sulfoaluminate-belite cements. Their quality has been improved. The replacement of 15 wt % of sulfoaluminate-belite cement by ordinary Portland cement influences strength positively and elasticity modulus values as well as hydrated phases and pore structure development of sulfoaluminate-belite/ordinary Portland cement blends relative to pure sulfoaluminate-belite cement systems. The above statements confirm the possible making technologies, when improvements in sulfoaluminate-belite cements quality will be achieved. One would then anticipate the competition in usages between sulfoaluminate-belite/ordinary Portland cement and blast furnace-slag Portland cement systems in the practice. It is important to consider because sulfoaluminate-belite cements are of great advantage from the viewpoint of energy savings and quantity of CO 2 released during their production. Thermal characteristics of the samples were studied by thermogravimetry and differential thermal analysis from room temperature to 1000 0 C in air atmosphere. Generally, four significant temperature regions on thermogravimetry curves with the respective differential thermal analysis peak temperature for all types of samples are observed (Authors)

  7. Properties of Cement Mortar Produced from Mixed Waste Materials with Pozzolanic Characteristics.

    Science.gov (United States)

    Yen, Chi-Liang; Tseng, Dyi-Hwa; Wu, Yue-Ze

    2012-07-01

    Waste materials with pozzolanic characteristics, such as sewage sludge ash (SSA), coal combustion fly ash (FA), and granulated blast furnace slag (GBS), were reused as partial cement replacements for making cement mortar in this study. Experimental results revealed that with dual replacement of cement by SSA and GBS and triple replacement by SSA, FA, and GBS at 50% of total cement replacement, the compressive strength (Sc) of the blended cement mortars at 56 days was 93.7% and 92.9% of the control cement mortar, respectively. GBS had the highest strength activity index value and could produce large amounts of CaO to enhance the pozzolanic activity of SSA/FA and form calcium silicate hydrate gels to fill the capillary pores of the cement mortar. Consequently, the Sc development of cement mortar with GBS replacement was better than that without GBS, and the total pore volume of blended cement mortars with GBS/SSA replacement was less than that with FA/SSA replacement. In the cement mortar with modified SSA and GBS at 70% of total cement replacement, the Sc at 56 days was 92.4% of the control mortar. Modifying the content of calcium in SSA also increased its pozzolanic reaction. CaCl(2) accelerated the pozzolanic activity of SSA better than lime did. Moreover, blending cement mortars with GBS/SSA replacement could generate more monosulfoaluminate to fill capillary pores.

  8. Heat of hydration measurements on cemented radioactive wastes. Part 1: cement-water pastes

    International Nuclear Information System (INIS)

    Lee, D.J.

    1983-12-01

    This report describes the hydration of cement pastes in terms of chemical and kinetic models. A calorimetric technique was used to measure the heat of hydration to develop these models. The effects of temperature, water/cement ratio and cement replacements, ground granulated blast furnace slag (BFS) and pulverised fuel ash (PFA) on the hydration of ordinary Portland cement (OPC) is reported. The incorporation of BFS or PFA has a marked effect on the hydration reaction. The effect of temperature is also important but changing the water/cement ratio has little effect. Results from cement pastes containing only water and cement yield total heats of reaction of 400, 200 and 100 kJ/kg for OPC, BFS and PFA respectively. Using the results from the models which have been developed, the effect of major salts present in radioactive waste streams can be assessed. Values of the total heat of reaction, the time to complete 50 percent reaction, and the energy of activation, can be compared for different waste systems. (U.K.)

  9. High temperature coke characteristics in the blast furnace:evaluation of coke properties in the raceway area

    OpenAIRE

    Lundgren, Maria; Sundqvist Ökvist, Lena; Hyllander, Gunilla; Jansson, Björn; Björkman, Bo

    2012-01-01

    Core-drilling into the coke bed of raceway and hearth has been performed in the LKAB Experimental Blast Furnace (EBF®) during short stoppages aiming to characterize raceway conditions corresponding to different operational conditions. All coke operation, injection of pulverized coal and injection of a mixture of coal and blast furnace flue dust (BFD) were evaluated and compared. The samples have been studied regarding particle size and distribution, coke have been evaluated with chemical comp...

  10. A theoretical study using the multiphase numerical simulation technique for effective use of H2 as blast furnaces fuel

    OpenAIRE

    Jose Adilson de Castro; Cyro Takano; Jun-ichiro Yagi

    2017-01-01

    We present a numerical simulation procedure for analyzing hydrogen, oxygen and carbon dioxide gases injections mixed with pulverized coals within the tuyeres of blast furnaces. Effective use of H2 rich gas is highly attractive into the steelmaking blast furnace, considering the possibility of increasing the productivity and decreasing the specific emissions of carbon dioxide becoming the process less intensive in carbon utilization. However, the mixed gas and coal injection is a complex techn...

  11. Green options for anti-sulfate of slag cement concrete containing pozzolans

    Directory of Open Access Journals (Sweden)

    Yang Chien-Jou

    2017-01-01

    Full Text Available This study mainly adopted densified mixture design algorithm (DMDA with pozzolans (fly ash and slag, different fineness slag cement (1:1; MF40 and HF40 and Type I cement (E40 to construct the mixtures for w/cm=0.40, and applied ACI 211.1R and Type II cement as control group (CII40, w/c=0.40. Life cycle inventory of LEED suggested by PCA for cementitious materials (kg/m3 contained cement use, CO2 emission, raw materials, energy consumption, compressive strength, and immersed in different concentration Na2SO4 solution. Results showed cement content, CO2 emission, raw materials and energy consumption for E40, MF40 and HF40, with respect to CII40, were 14% ∼ 26%, 14% ∼ 26%, 13% ∼ 26% and 17%∼28%. At 28 days, compressive strength(all mixtures were greater than 41MPa. Repeatedly 25 cycles, specimens immersed in 5000ppm Na2SO4 solution and oven-dried at 105°C, the exterior had no damage, and weight loss (n and pulse velocity change (nv were less than -1% and -5%. But in saturated Na2SO4 solution, the n and nv were ranged from - 0.91% (E40 to -2.62% (MF40 and -6.7% (E40 to -10.9% (MF40. The exterior had been obviously scaling (chalking or spalling at the second (CII40, the fifth (MF40 and HF40 and the ninth cycle (E40. The comprehensive evaluation of green options for anti-sulfate indicated that the merits of all mixtures were respectively E40 > HF40 > MF40 > CII40.

  12. Modelling and prediction of pig iron variables in the blast furnace

    Energy Technology Data Exchange (ETDEWEB)

    Saxen, H.; Laaksonen, M.; Waller, M. [Aabo Akademi, Turku (Finland). Heat Engineering Lab.

    1996-12-31

    The blast furnace, where pig iron for steelmaking is produced, is an extremely complicated process, with heat and mass transfer and chemical reactions between several phases. Very few direct measurements on the internal state are available in the operation of the process. A main problem in on-line analysis and modelling is that the state of the furnace may undergo spontaneous changes, which alter the dynamic behaviour of the process. Moreover, large internal disturbances frequently occur, which affect the product quality. The work in this research project focuses on a central problem in the control of the blast furnace process, i.e., short-term prediction of pig iron variables. The problem is of considerable importance for fuel economy, product quality, and for an optimal decision making in integrated steel plants. The operation of the blast furnace aims at producing a product (hot metal) with variables maintained on a stable level (close to their setpoints) without waste of expensive fuel (metallurgical coke). The hot metal temperature and composition affect the downstream (steelmaking) processes, so fluctuations in the pig iron quality must be `corrected` in the steel plant. The goal is to develop a system which predicts the evolution of the hot metal variables (temperature, chemical composition) during the next few taps, and that can be used for decision-making in the operation of the blast furnace. Because of the complicated behaviour of the process, it is considered important to include both deterministic and stochastic components in the modelling: Mathematical models, which on the basis of measurements describe the physical state of the process, and statistical (black-box) models will be combined in the system. Moreover, different models will be applied in different domains in order to capture structural changes in the dynamics of the process SULA 2 Research Programme; 17 refs.

  13. Development of aluminium free castable for blast furnace trough materials. Koro toiyo Al mutenka nagashikomizai no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Yaoi, H.; Tsutsui, N.; Suzuki, T. (Nippon Steel Corp., Tokyo (Japan)); Yoshino, H.; Sugiyama, K.; Yasuda, N.; Ninomiya, H.; Itose, S. (Harima Co. Ltd., Hyogo (Japan))

    1992-09-10

    In recent years a densification of castable materials is being developed in order to elongate a life of the blast furnace trough. As a risk of dry expansion in the drying process becomes to be higher due to it, the castable materials added the metallic Al are being used as a countermeasure against it. Since the metallic Al generates the hydrogen gas by a reaction with the water and forms the vent holes, it is superior in an explosion resistance. When the hydrogen gas generated by a reaction of this metallic Al retains during a period from the execution to the curing, there is a danger to generate an explosion by catching a fire. Accordingly in this repost, the organic foaming agent was added as the castable materials free from the metallic Al. As a result, an explosion resistance could be raised substantially. This is thought due to generation of N2 gas because the hydrolysis occurs in an alumina cement-water system. The microporess caused by a generation of N2 gas are a size of about 10[mu]m, or many of them are bigger than it. Although the effect of the added organic foaming agent on the various material property values is a little, an appropriate quantity is thought to be within 0.2%. 1 ref., 8 figs., 3 tabs.

  14. Optimization of a Steel Plant with Multiple Blast Furnaces Under Biomass Injection

    Science.gov (United States)

    Wiklund, Carl-Mikael; Pettersson, Frank; Saxén, Henrik

    2013-04-01

    The allocation of resources between several blast furnaces in an integrated steelmaking plant is studied with the aim of finding the lowest specific operation cost for steel production. In order to reduce the use of fossil fuels, biomass was considered as an auxiliary reductant in the furnace after partial pyrolysis in an external unit, as a complement to heavy fuel oil. The optimization considers raw material, energy, and emission costs and a possible credit for sold power and heat. To decrease computational requirements and to guarantee that the global optimum is found, a piecewise linearized model of the blast furnace was used in combination with linear models of the sinter-, coke-, and power plants, hot stoves, and basic oxygen furnace. The optimization was carried out under different constraints on the availability of some raw materials as well as for different efficiencies of the hot stoves of the blast furnaces. The results indicate that a non-uniform distribution of the production between the furnaces can be advantageous, and some surprising findings concerning the optimal resource allocation under constrained operation are reported.

  15. Effect of blastfurnace slag addition to Portland cement for cationic exchange resins encapsulation

    Directory of Open Access Journals (Sweden)

    Stefan L.

    2013-07-01

    Full Text Available In the nuclear industry, cement-based materials are extensively used to encapsulate spent ion exchange resins (IERs before their final disposal in a repository. It is well known that the cement has to be carefully selected to prevent any deleterious expansion of the solidified waste form, but the reasons for this possible expansion are not clearly established. This work aims at filling the gap. The swelling pressure of IERs is first investigated as a function of ions exchange and ionic strength. It is shown that pressures of a few tenths of MPa can be produced by decreases in the ionic strength of the bulk solution, or by ion exchanges (2Na+ instead of Ca2+, Na+ instead of K+. Then, the chemical evolution of cationic resins initially in the Na+ form is characterized in CEM I (Portland cement and CEM III (Portland cement + blastfurnace slag cements at early age and an explanation is proposed for the better stability of CEM III material.

  16. The effect of blast furnace slag on the self-compactability of pumice ...

    Indian Academy of Sciences (India)

    2018-04-02

    Apr 2, 2018 ... So far, the use of pumice was dependent on the availability and limited in the countries where it is locally .... admixture was used to reduce the risk of segregation and to increase the cohesion in some cases. ..... diameter of 50 cm is related to flow rate and plastic viscosity of concrete. The shear stress and ...

  17. The effect of blast furnace slag on the self-compactability of pumice ...

    Indian Academy of Sciences (India)

    Faculty of Architecture & Design, Department of Architecture, Atatürk University, 25240 Erzurum, Turkey; Engineering & Architecture Faculty, Department of Civil Engineering, Erzurum Technical University, 25070 Erzurum, Turkey; Engineering Faculty, Department of Civil Engineering, Atatürk University, 25240 Erzurum, ...

  18. Granulated blast furnace slag – A boon for foundry industry | Murthy ...

    African Journals Online (AJOL)

    The PDF file you selected should load here if your Web browser has a PDF reader plug-in installed (for example, a recent version of Adobe Acrobat Reader). If you would like more information about how to print, save, and work with PDFs, Highwire Press provides a helpful Frequently Asked Questions about PDFs.

  19. Study of some health physics parameters of bismuth-ground granulated blast furnace slag shielding concretes

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Sandeep, E-mail: sandeep0078monu@gmail.com [Department of Physics, Punjabi University, Patiala (India); Singh, Sukhpal, E-mail: sukhpal-78@rediffmail.com [Department of Basic and Applied Sciences, Punjabi University, Patiala (India)

    2016-05-06

    The Bismuth-ground granulated blastfurnace slang (Bi-GGBFS) concrete samples were prepared. The weight percentage of different elements present in Bi-GGBFS Shielding concretewas evaluated by Energy Dispersive X-ray Microanalysis (EDX). The exposure rate and absorbed dose rate characteristics were calculated theoretically for radioactive sources namely {sup 241}Am and {sup 137}Cs. Our calculations reveal that the Bi-GGBFS concretes are effective in shielding material for gamma radiations.

  20. Evaluation of Portland cement from X-ray diffraction associated with cluster analysis

    International Nuclear Information System (INIS)

    Gobbo, Luciano de Andrade; Montanheiro, Tarcisio Jose; Montanheiro, Filipe; Sant'Agostino, Lilia Mascarenhas

    2013-01-01

    The Brazilian cement industry produced 64 million tons of cement in 2012, with noteworthy contribution of CP-II (slag), CP-III (blast furnace) and CP-IV (pozzolanic) cements. The industrial pole comprises about 80 factories that utilize raw materials of different origins and chemical compositions that require enhanced analytical technologies to optimize production in order to gain space in the growing consumer market in Brazil. This paper assesses the sensitivity of mineralogical analysis by X-ray diffraction associated with cluster analysis to distinguish different kinds of cements with different additions. This technique can be applied, for example, in the prospection of different types of limestone (calcitic, dolomitic and siliceous) as well as in the qualification of different clinkers. The cluster analysis does not require any specific knowledge of the mineralogical composition of the diffractograms to be clustered; rather, it is based on their similarity. The materials tested for addition have different origins: fly ashes from different power stations from South Brazil and slag from different steel plants in the Southeast. Cement with different additions of limestone and white Portland cement were also used. The Rietveld method of qualitative and quantitative analysis was used for measuring the results generated by the cluster analysis technique. (author)

  1. Microstructure of hydrated cement pastes as determined by SANS

    International Nuclear Information System (INIS)

    Sabine, T.; Bertram, W.; Aldridge, L.

    1999-01-01

    Full text: Technologists have known how to make concrete for over 2000 years but despite painstaking research no one has been able to show how and why concrete sets. Part of the problem is that the calcium silicate hydrate (the gel produced by hydrating cement) is amorphous and cannot be characterised by x-ray crystallographic techniques. Small angle neutron scattering on instrument V12a at BENSC was used to characterise the hydration reactions and show the growth of the calcium silicate hydrates during initial hydration and the substantial differences in the rate of growth and structure as different additives are used. SANS spectra were measured as a function of the hydration from three different types of cement paste: 1) Ordinary Portland Cement made with a water to cement ratio of about 0.4; 2) A blend of Ordinary Portland Cement(25%) and Ground Granulated Blast Furnace Slag (75%) with a water to cement ration of about 0.4; 3) A dense paste made from silica fume(24%), Ordinary Portland Cement (76%) at a water to powder ratio of 0.18. The differences in the spectra are interpreted in terms of differences between the microstructure of the pastes

  2. Ternary blended cement concrete. Part I: early age properties and mechanical strength

    Directory of Open Access Journals (Sweden)

    Irassar, E. F.

    2006-12-01

    Full Text Available While there is ample information in the literature on the mechanical performance and durability of concrete made with either limestone or granulated blast furnace slag,very little is known about the effect of the combined action of these two additions on concrete properties. The present paper evaluates the early stage properties and mechanical strength of binary and ternary cement concrete containing up to 18% limestone and 20% granulated blast furnace slag. The results show that the use of ternary cements has no substantial effect on concrete setting time, although it does reduce bleeding and enhance mechanical strength with respect to unadditioned Portland and/or binary cement concrete.En la bibliografía existe abundante información acerca del comportamiento mecánico y durable de hormigones elaborados con la incorporación individual de caliza y de escoria granulada de alto horno. Sin embargo, la modificación de las propiedades por la acción conjunta de las mismas es prácticamente desconocida. En este trabajo se evalúan las propiedades en estado fresco y el comportamiento mecánico de hormigones elaborados con cementos compuestos binarios y ternarios conteniendo hasta 18% de caliza y 20% de escoria granulada de alto horno. Los resultados indican que la utilización de cementos ternarios en hormigones no modifican sustancialmente el tiempo de fraguado, disminuyen la exudación y presentan un mejor comportamiento mecánico que los hormigones elaborados con cemento Portland sin adición y/o binarios.

  3. Sodium Silicate Gel Effect on Cemented Tailing Backfill That Contains Lead-Zinc Smelting Slag at Early Ages

    Directory of Open Access Journals (Sweden)

    Lijie Guo

    2018-01-01

    Full Text Available This paper presents the results of an experimental study on the priming effect of sodium silicate gel (SS on cemented tailing backfill (CTB that contains lead-zinc smelting slag. CTB and cemented paste (CP containing lead-zinc smelting slag samples with SS of 0 and 0.4% of the mass of the slag were prepared and cured at 20°C for 1, 3, 7, and 28 days. Mechanical test and pore structure analyses were performed on the studied CTB samples, microstructural analyses (X-ray diffraction analysis and thermal gravity analysis were performed on the studied CP samples, whereas the electrical conductivity of CTB was monitored. The results reveal that SS has a significant positive effect on cementitious activity of binder mixed by cement and lead-zinc smelting slag. This activation leads to the acceleration of binder hydration process, the formation of more cement hydration products in the CTBs, and the refinement of their pore structure, which is favorable for the strength development of CTB.

  4. Immobilization in cement of ion exchange resins from Spanish nuclear reactors

    International Nuclear Information System (INIS)

    Huebra, A.G. de la; Murillo, R.; Ortiz, S.J.

    1990-01-01

    Ion exchange materials used at nuclear power plants can be immobilized in cements less expensive than polymer matrices. Cement solidification of spent ion exchange resins shows swelling and cracking troubles (during setting time, or of storage). The objective of this study was to select the types of cement that produce the best quality on immobilization of three kinds of resins and to set up cement formulations containing the maximum possible loading of resin. Four cements were selected to carried out the study. After a study of hydration-dehydration phenomena of ion exchange resins, a systematic work has been carried out on immobilization. Tests were performed to study compressive strength and underwater stability by changing water/cement ratio and resin/cement ratio. Mixtures made with water, cement and resin only were loaded with 10% by weight dry resin. Mixtures with higher loadings show poor workability. Tests were carried out by adding organic plasticizers and silica products to improve waste loading. Plasticizers reduced water demand and silica products permit the use of more water. Leaching tests have been performed at 40 O C. In conclusion Blast Furnace Slag is the best cement for immobilization of ion exchange resin both bead and powdered form for mechanical strength, stability and leaching

  5. Studying the effect of thermal and acid exposure on alkali activated slag Geopolymer

    Directory of Open Access Journals (Sweden)

    Khater H.M.

    2014-04-01

    Full Text Available This article reports a study about thermal stability as well as acid resistance of geopolymer materials prepared from Ground Granulated Blast Furnace Slag (GGBFS, Air Cooled Slag (ACS, Silica fume (SF and cement kiln dust (CKD using 6% (weight of equal mix from alkaline sodium hydroxide and sodium silicate activators. Study of addition of ACS, SF and CKD as partial replacement of GGBFS is investigated so as to improve the mechanical and microstructural properties of geopolymer mixes. Compressive strength and SEM were utilized in these studies. Materials were prepared using water/binder of 0.30 at 38°C and 100% RH. Results showed that geopolymer materials prepared using alkali activated slag exhibit large changes in compressive strength with increasing the firing temperature from 300 to 1000°C and exhibit an enhancement in thermal stability as compared to concrete specimens. Materials prepared by replacing GGBFS by 15% ACS resist thermal deterioration up to 1000°C. It was suggested to be suitable for refractory insulation applications as well as for production of nuclear concrete reactors. On the other hand, geopolymer mixes exhibit low stability upon subjecting to different concentration from the mix of nitric and hydrochloric acid in equal ratio (1:1. Current studies of geopolymer microstructure were focused on the morphology as well as the relationship between compositions and mechanical properties.

  6. Thermal analysis evaluation of the reactivity of coal mixtures for injection in the blast furnace

    Directory of Open Access Journals (Sweden)

    Maria de Lourdes Ilha Gomes

    2006-03-01

    Full Text Available Pulverized Coal Injection (PCI is an important standard technology replacing coke partially by pulverized coal into the blast furnace that allows a significant reduction of hot metal costs and environmental impact, contributing to a decrease of coke requirements for ironmaking. Coals typically used in this process in Brazil are, at current time, exclusively imported from many countries, although economic important coal-measures occur in the southern part of the country. The Brazilian coals have a low rank, higher contents of inert components, proportioning nocoking properties and an expected high reactivity. Due to these caractheristics, these coals could be used for injection in the blast furnaces in order to decrease the dependency on high cost imported coals. The efficiency in the combustion and the coal reactivity are considered important parameters in the blast furnace, since a larger amount of char (unburned coal causes severe problems to the furnace operation. The aim of the present work is to compare the reactivity of a south Brazilian coal, obtained from Faxinal mine, with two imported coals and the blends of the Brazilian coal with the imported ones. The reactivity of these coals and their blends were evaluated in a thermogravimetric analyzer. In the experiments, various mass ratios of Faxinal coal and the imported coals were used to compose the blends. The gasification reaction with pure CO2 was conducted under isothermal conditions at 1050 °C and atmospheric pressure. The experimental results show the greater reactivity of the Faxinal coal. The additive behavior was confirmed. The blends with a composition of up to 50% Faxinal coal have parameters according to the usual limits used for PCI.

  7. Soot formation in a blast furnace - Prediction via a parametric study, using detailed kinetic modeling

    Energy Technology Data Exchange (ETDEWEB)

    Nordstroem, T.; Kilpinen, P.; Hupa, M. [Aabo Akademi, Turku (Finland). Combustion Chemistry Group

    1996-12-31

    The objective of this work has been to investigate the soot formation in a blast furnace fired with heavy fuel oil, using detailed kinetic modelling. This work has been concentrated on parameter studies that could explain under which conditions soot is formed and how that formation could be avoided. The parameters investigated were temperature, pressure, stoichiometric ratio, pyrolysis gas composition and reactor model. The calculations were based on a reaction mechanism that consists of 100 species and 446 reactions including polyaromatic hydrocarbons (PAM) up to 7 aromatic rings SULA 2 Research Programme; 4 refs.

  8. Hot metal temperature prediction in blast furnace using advanced model based on fuzzy logic tools

    Energy Technology Data Exchange (ETDEWEB)

    Martin, R.D.; Obeso, F.; Mochon, J.; Barea, R.; Jimenez, J.

    2007-05-15

    The present work presents a model based on fuzzy logic tools to predict and simulate the hot metal temperature in a blast furnace (BF). As input variables this model uses the control variables of a current BF such as moisture, pulverised coal injection, oxygen addition, mineral/coke ratio and blast volume, and it yields as a result of the hot metal temperature. The variables employed to develop the model have been obtained from data supplied by current sensors of a Spanish BF In the model training stage the adaptive neurofuzzy inference system and the subtractive clustering algorithms have been used.

  9. Continual Measuring of Local Stress Values on Shell of the Blast Furnace Hearth and of Total Shell Expansion

    Directory of Open Access Journals (Sweden)

    P. Bigoš

    2012-01-01

    Full Text Available This paper deals with installation of strain gauges on the external surface of the blast furnace shell in two rows, whereas there will be defi ned 8 measuring points in every row. The fi nal result is evaluation of data obtained during up to 45 days of the operation. In this papers are commentary and discussions to measured time behaviours. The main purpose of this measuring was investigation of impact of salamander on blast furnace shell expansion after its lay off , cooling and next starting of operation.

  10. Oxygen blast furnace and combined cycle (OBF-CC) - an efficient iron-making and power generation process

    International Nuclear Information System (INIS)

    Jianwei, Y.; Guolong, S.; Cunjiang, K.; Tianjun, Y.

    2003-01-01

    A new iron and power generating process, oxygen blast furnace and combined cycle (OBF-CC), is presented. In order to support the opinion, the features of the oxygen blast furnace and integrated coal gasification and combined cycle (IGCC) are summarized. The relation between the blasting parameters and the output gas quantity, as well as caloric value is calculated based on mass and energy balance. Analysis and calculation indicate that the OBF-CC will be an efficient iron-making and power generation process with higher energy efficiency and less pollution

  11. Steelmaking slag beneficiation by magnetic separator and impacts on sinter quality

    Directory of Open Access Journals (Sweden)

    Bölükbaşı Ö.S.

    2014-01-01

    Full Text Available Basic oxygen furnaces (BOF slag is the main problem at all iron and steel factories. About more than 6 million tons/year of BOF slag has been accumulated from the waste stockyards in Turkey. Dumps slags can be revaluated by a processing technology which makes it possible to obtain products that meet the requirements of sintering and blast furnace production. The slags with particle size of -10 mm were enriched by the magnetic separator resulting and increase in Fe grade from 18% to 33%. The use of BOF slag in sinter blend provided additional Mn, CaO, MgO and introduced a good solution to environmental problems.

  12. Research of magnesium phosphosilicate cement

    Science.gov (United States)

    Ding, Zhu

    Magnesium phosphosilicate cement (MPSC) is a novel phosphate bonded cement, which consists mainly of magnesia, phosphate and silicate minerals. The traditional magnesium phosphate cements (MPCs) usually composed by ammonium phosphate, and gaseous ammonia will emit during mixing and in service. There is no noxious ammonia released from MPSC, furthermore, it can recycle a large volume of the non-hazardous waste. The goal of this research is to investigate the composition, reaction products, reaction mechanism, microstructure, properties, durability and applications of the MPSC. MPSC sets rapidly and has high early strength. It reacts better with solid industrial waste when compared to Portland cement. Many solid industrial wastes, such as fly ash, steel slag, coal gangue, red coal gangue, red mud, barium-bearing slag, copper slag, silica fume, and ground granulated blast furnace slag, have been used as the main component (40% by weight) in MPSC. The research has found that these aluminosilicate (or ironsilicate, or calciumsilicate) minerals with an amorphous or glass structure can enhance the performance of MPSC. The disorganized internal structure of amorphous materials may make it possess higher reactivity compared to the crystalline phases. Chemical reaction between phosphate and these minerals may form an amorphous gel, which is favorable to the cementing. Borax, boric acid and sodium tripolyphosphate have been used as retardants in the MPSC system. It is found that boric acid has a higher retarding effect on the setting of cement, than borax does. However, sodium polyphosphate accelerates the reaction of MPSC. The hydration of MPSC is exothermic reaction. The heat evolution may prompt hydrates formation, and shorten the setting process. Modern materials characterization techniques, XRD, DSC, TG-DTA FTIR, XPS, MAS-NMR, SEM, TEM, MIP, etc. were used to analyze the phase composition, micro morphology, and microstructure of hardened MPSC. The main hydration product

  13. Effects of heat treatments of coal on coke destruction under blast furnace conditions

    Energy Technology Data Exchange (ETDEWEB)

    Shkoller, M.B.; Dinel' t, V.M.; Korchuganova, G.S.; Petrov, V.B.

    1983-09-01

    This paper discusses results of investigations on effects of chemical reactions in a blast furnace on coke disintegration and destruction. The investigations were carried out by the VUKhIN Institute branch in Kuznetsk. Effects of silicates and carbonates of sodium, potassium and zinc on mechanical coke properties were investigated under laboratory conditions. Coke samples were placed in a reactor and were treated by vapors of metal compounds. Coke produced from a coal mixture with conventional moisture content and from preheated coal mixture was used. Coal properties are given in a table. Design of laboratory equipment used for tests is shown in 2 schemes. Heat treatments influenced coke porosity and its structural strength. Proportion of large pores accessible to sodium and potassium in coke from preheated coal was 4.5 times lower than in coke from a conventional mixture. Adsorption of sodium and potassium on coke from preheated charge was lower (from 0.22% to 0.24%) than on coke from a conventional mixture (from 2.5% to 2.9%). Adsorption of alkali metals on coke reduced its structural strength and increased coke oxidation rate by carbon dioxide. Use of heat treatments of coal for coking reduced adsorption of alkali metals on coke in a blast furnace, increased coke structural strength and reduced coke oxidation rate by carbon dioxide. (16 refs.) (In Russian)

  14. A new concept of auxiliary fuel injection through tuyeres in blast furnaces developed by numerical simulations

    Directory of Open Access Journals (Sweden)

    Bruno Orlando de Almeida Santos

    2014-04-01

    Full Text Available The Injection of powdered materials in blast furnaces is a great option for reducing costs, increasing productivity and satisfy the environmental norms. Thus, this paper presents a study on the use of a flame stabilization system with rotation, designed to promote greater coal injection in the combustion zone, reducing losses and increasing the efficiency of the equipment. A physical model was used to evaluate scattering of pulverized fuel and is compared with numerical results in the same scale. In the second step, a combustion model was added to the numerical simulation, using dimensions of a real blast furnace. Fields like temperature, velocity and behavior of chemical reactions were analyzed. The results showed that double lances promote better particle injection when compared with simple lance for reduced material injection. The new injection system proposed, with swirl numbers of 0.12 and 0.24, promoted a better injection of both reduced material and temperature in the raceway zone. The swirl 0.24 showed superior performance when compared to other injection systems.

  15. Multi-parameter measurements in a blast furnace using interactions of neutrons and γ-rays

    International Nuclear Information System (INIS)

    Shirakawa, Yoshiyuki; Horikoshi, Kiyomi

    1998-01-01

    This paper describes the possibility of multi-parameter measurements to meet the requirements for more precise and stable control of a blast furnace. A basic concept of such measurements is to make use of multi-radiations of neutrons and γ-rays, and to obtain multi-types of information on conditions of materials (iron ore and coke) inside the blast furnace. A prototype gauge was assembled and examined which consisted of a radiation source of 252 Cf, a neutron moderator, a lead shield, a bismuth germanate detector, a stainless casing and a control unit. Laboratory experiments showed that the gauge could measure the quantities to be essential to estimate material conditions. In practice, it clearly distinguished between iron ore and coke layers, and at the same time measured bulk density of iron contained in iron ore by counting thermal neutron capture γ-rays from iron. It also gave the information on material bulk density by detecting Compton scattered γ-rays from material, i.e. iron ore and coke. Finally, reducibility of iron ore was calculated by using both bulk densities. Relative accuracy of measurements was reasonable in practical use. The possibility of realization of the gauge has been proved and the on-line trial will be expected in the near future. (author)

  16. An intervention for noise control of blast furnace in steel industry.

    Science.gov (United States)

    Golmohammadi, Rostam; Giahi, Omid; Aliabadi, Mohsen; Darvishi, Ebrahim

    2014-01-01

    Noise pollution is currently a major health risk factor for workers in industries. The aim of this study was to investigate noise pollution and implement a control intervention plan for blast furnace in a steel industry. The measurement of sound pressure level (SPL) along with frequency analysis was done with the sound-level-meter Cell-450. Personal noise exposure was performed using dosimeter TES-1345 calibrated with CEL-282. Before planning noise controls, acoustic insulation properties of the furnace control unit and workers' rest room were assessed. Control room and workers' rest room were redesigned in order to improve acoustical condition. The SPL before intervention around the Blast Furnace was 90.3 dB (L) and its dominant frequency was 4000 Hz. Besides, noise transmission loss of the control and rest rooms were 10.3 dB and 4.2 dB, respectively. After intervention, noise reduction rates in the control and rest rooms were 27.4 dB and 27.7 dB, respectively. The workers' noise dose before and after the intervention was 240% and less than 100%, respectively. Improvement the workroom acoustic conditions through noise insulation can be considered effective method for preventing workers exposure to harmful noise.

  17. Effect of recycling blast furnace flue dust as pellets on the sintering performance

    Directory of Open Access Journals (Sweden)

    El-Hussiny N.A.

    2010-01-01

    Full Text Available The Egyptian Iron and Steel Company generates a great amount of blast furnace flue dust. The recovery of metals and carbon from this flue dust becomes a very important demand due to the increase of the price of coke breeze and the decrease of the primary source of metals. At the same time, it make the environment more safe by decreasing pollution. Introducing these dust fines in the sintering process proves to be very harmful for different operating parameters. Thus, this study aims at investigating the production of pellets resulting from these fines, using molasses as organic binder and its application in sintering of iron ore. The sintering experiments were performed using flue dust as pellets as a substitute of coke breeze. The results revealed that, sintering properties such as inter strength increases with using the flue dust pellets, while productivity of both the sinter machine and sinter machine at blast furnace yard decreases. Also the vertical velocity of the sinter machine and the weight loss during the reduction of produced the sinter by hydrogen decrease.

  18. Exergo-Ecological Assessment Of Auxiliary Fuel Injection Into Blast-Furnace

    Directory of Open Access Journals (Sweden)

    Stanek W.

    2015-06-01

    Full Text Available Metallurgy represents complex technological chain supplied with different kinds of primary resources. Iron metallurgy based on blast-furnace process, dominates in world steel production. Metallurgical coke is the basic fuel in this case. Its production is connected with several environmental disadvantageous impacts. One of them is the extended production chain from primary energy to final energy. The reduction of coke consumption in the process can be achieved e.g. by injection of auxiliary fuels or increasing the thermal parameters in the process. In present injection of pulverised coal dominates while recirculation of top-gas seems to be future technology. However, the latter one requires the CO2 removal that additionally extended the production chain. The evaluation of resources management in complex energy-technological systems required application of advanced method based on thermodynamics. In the paper the system exergo-ecological assessment of pulverised coal injection into blast-furnace and top-gas recirculation has been applied. As a comparative criterion the thermo-ecological cost has been proposed.

  19. Utilizing of the metallurgical slag for production of cementless concrete mixtures

    Directory of Open Access Journals (Sweden)

    D. Baricová

    2012-10-01

    Full Text Available In process of pig iron, steel and cast iron production besides main product, also secondary products are formed, that have character of secondary raw materials and industrial wastes. The most abundant secondary product originating in the metallurgical process is furnace slag. Total amount of accured slag, also its chemical, mineralogical, physical – chemical properties and similarity with natural stones predestinate its utilisation in different fields of industry. The contribution deals with production of cementless concrete mixtures, where the main parts were formed by blast furnace granulated slag grinded and different gravel slag from blast furnace, oxygen converter and electric arc furnace. As activators of solidification different kinds of water glass were tested.

  20. Self-degradable Slag/Class F Fly Ash-Blend Cements

    Energy Technology Data Exchange (ETDEWEB)

    Sugama, T.; Warren, J.; Butcher, T. (BNL); Lance Brothers (Halliburton); Bour, D. (AltaRock Energy, Inc.)

    2011-03-01

    Self-degradable slag/Class F fly ash blend pozzolana cements were formulated, assuming that they might serve well as alternative temporary fracture sealers in Enhanced Geothermal System (EGS) wells operating at temperatures of {ge} 200 C. Two candidate formulas were screened based upon material criteria including an initial setting time {ge} 60 min at 85 C, compressive strength {ge} 2000 psi for a 200 C autoclaved specimen, and the extent of self-degradation of cement heated at {ge} 200 C for it was contacted with water. The first screened dry mix formula consisted of 76.5 wt% slag-19.0 wt% Class F fly ash-3.8 wt% sodium silicate as alkali activator, and 0.7 wt% carboxymethyl cellulose (CMC) as the self-degradation promoting additive, and second formula comprised of 57.3 wt% slag, 38.2 wt% Class F fly ash, 3.8 wt% sodium silicate, and 0.7 wt% CMC. After mixing with water and autoclaving it at 200 C, the aluminum-substituted 1.1 nm tobermorite crystal phase was identified as hydrothermal reaction product responsible for the development of a compressive strength of 5983 psi. The 200 C-autoclaved cement made with the latter formula had the combined phases of tobermorite as its major reaction product and amorphous geopolymer as its minor one providing a compressive strength of 5271 psi. Sodium hydroxide derived from the hydrolysis of sodium silicate activator not only initiated the pozzolanic reaction of slag and fly ash, but also played an important role in generating in-situ exothermic heat that significantly contributed to promoting self-degradation of cementitious sealers. The source of this exothermic heat was the interactions between sodium hydroxide, and gaseous CO{sub 2} and CH{sub 3}COOH by-products generated from thermal decomposition of CMC at {ge} 200 C in an aqueous medium. Thus, the magnitude of this self-degradation depended on the exothermic temperature evolved in the sealer; a higher temperature led to a sever disintegration of sealer. The exothermic

  1. Solidification of Simulated Radioactive Incineration Ash by Alkali-activated Slag Composite Cement

    International Nuclear Information System (INIS)

    Li changcheng; Cui Qi; Zhao Yanhong; Pan Sheqi

    2010-01-01

    Simulated radioactive incineration ash (SRIA) was solidified by alkali-activated slag composite cement (AASCC) modified by metakaolin, zeolite, and polymer emulsion powder. The results show that the performance of solidified waste form containing 40% SRIA meets the requirements of GB 14569.1-93. The lowest leaching rate of Cs + on 42nd days reaches 1.32 x 10 -4 cm/d (GB 7023-86,25 degree C), cumulative leach percentage is only 0.041 cm. Also, the lowest 28 days compressive strength of solidified waste form is 45.6 MPa, and later strength growth is still high. The fast setting characteristic of AASCC overcomes effectively the disadvantageous influence caused by some components in SRIA on hydration of cement. The compressive strength of solidified waste is enhanced remarkably, and the ability of immobilizing radionuclide ions is also improved. This is mainly due to synergistic effect between metakaolin and zeolite. Polymer modification also improves the performance of solidified waste form significantly. The three-dimensional polymer network structure formed by emulsion powder in solidified waste form enhances its toughness and impact resistance, and the durability is improved by reducing interconnected pores and optimizing pore structure. However,it also results in reduction in compressive strength. Thus, it is concluded that the suitable dosage percentage is 5%. (authors)

  2. Effect of Metakaolin and Slag blended Cement on Corrosion Behaviour of Concrete

    Science.gov (United States)

    Borade, Anita N.; Kondraivendhan, B.

    2017-06-01

    The present paper is aimed to investigate the influence of Metakaolin (MK) and Portland slag Cement (PSC) on corrosion behaviour of concrete. For this purpose, Ordinary Portland Cement (OPC) was replaced by 15% MK by weight and readymade available PSC were used. The standard concrete specimens were prepared for both compressive strength and half- cell potential measurement. For the aforesaid experiments, the specimens were cast with varying water to binder ratios (w/b) such as 0.45, 0.5 and 0.55 and exposed to 0%, 3%, 5% and 7.5% of sodium chloride (NaCl) solution. The specimens were tested at wide range of curing ages namely 7, 28, 56, 90 and 180 days. The effects of MK, w/b ratio, age, and NaCl exposure upon concrete were demonstrated in this investigation along with the comparison of results of both MK and PSC concrete were done. It was also observed that concrete with MK shows improved performance as compared to concrete with PSC.

  3. Evolution of pH in a radwaste repository: leaching of modified cements and reactions with groundwater

    International Nuclear Information System (INIS)

    Atkinson, A.; Guppy, R.M.

    1988-01-01

    Cementitious materials in radioactive waste repositories establish high pH which brings many benefits. The pH will change with time as the chemical constituents responsible for it are leached away. This has been simulated in the laboratory for a Sulphate Resisting Portland Cement (SRPC), a slag-modified cement composed of 90% Blast Furnace Slag (BFS) and 10% Ordinary Portland Cement (OPC) and an ash-modified cement containing 90% Pulverized Fuel Ash (PFA) and 10% OPC. They have been leached in demineralised water and a synthetic groundwater typical of a clay environment. Leachate analyses for a variety of elements showed that the leachate was not usually in equilibrium with any of the solid phases. Nevertheless the experimental evolution of pH was not too different from that predicted by assuming equilibrium and the predictions offer a means of estimating a lower bound for pH as it evolves in a real repository. The experiments with synthetic groundwater showed that the dominant effect influencing pH was precipitation of CaCO 3 from bicarbonates in the groundwater resulting in a reduction in both pH and buffer capacity. The ash-modified cement has particularly poor pH-buffering performance which is exacerbated in the groundwater. (author)

  4. Application of a clay-slag geopolymer matrix for repairing damaged concrete: Laboratory and industrial-scale experiments

    Czech Academy of Sciences Publication Activity Database

    Perná, Ivana; Hanzlíček, Tomáš; Boura, P.; Lučaník, A.

    2017-01-01

    Roč. 59, č. 10 (2017), s. 929-937 ISSN 0025-5300 Institutional support: RVO:67985891 Keywords : blast-furnace slag * geopolymer * scanning electron microscopy (SEM) * damaged concrete repair * long-term monitoring Subject RIV: JJ - Other Materials OBOR OECD: Composites (including laminates, reinforced plastics, cermets, combined natural and synthetic fibre fabrics Impact factor: 0.418, year: 2016

  5. Productivity and performance of small scale blast furnaces; Produtividade e performance de altos fornos de pequeno porte

    Energy Technology Data Exchange (ETDEWEB)

    Melo, Vamberto Ferreira de; Grandin, Friedrich Hans G.; Lanna, Pitagoras Gomes de; Castello Branco, Marco Antonio S.C. [Mannesmann SA, Belo Horizonte, MG (Brazil)

    1994-05-01

    This work presents some data concerning the re-start of the blast furnace number 2 of Mannesmann siderurgic company. The main characteristics concerning the operation with 100% coke fuel and the measurements adopted to increase the furnace productivity are described 2 refs., 6 figs., 5 tabs

  6. Influence of Titanium Dioxide Nanoparticles on the Sulfate Attack upon Ordinary Portland Cement and Slag-Blended Mortars.

    Science.gov (United States)

    Qudoos, Abdul; Kim, Hong Gi; Ryou, Jae-Suk

    2018-02-28

    In this study, the effects of titanium dioxide (TiO₂) nanoparticles on the sulfate attack resistance of ordinary Portland cement (OPC) and slag-blended mortars were investigated. OPC and slag-blended mortars (OPC:Slag = 50:50) were made with water to binder ratio of 0.4 and a binder to sand ratio of 1:3. TiO₂ was added as an admixture as 0%, 3%, 6%, 9% and 12% of the binder weight. Mortar specimens were exposed to an accelerated sulfate attack environment. Expansion, changes in mass and surface microhardness were measured. Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), X-ray Diffraction (XRD), Thermogravimetry Analysis (TGA) and Differential Scanning Calorimetry (DSC) tests were conducted. The formation of ettringite and gypsum crystals after the sulfate attack were detected. Both these products had caused crystallization pressure in the microstructure of mortars and deteriorated the mortars. Our results show that the addition of nano-TiO₂ accelerated expansion, variation in mass, loss of surface microhardness and widened cracks in OPC and slag-blended mortars. Nano-TiO₂ containing slag-blended mortars were more resistant to sulfate attack than nano-TiO₂ containing OPC mortars. Because nano-TiO₂ reduced the size of coarse pores, so it increased crystallization pressure due to the formation of ettringite and gypsum thus led to more damage under sulfate attack.

  7. Influence of Titanium Dioxide Nanoparticles on the Sulfate Attack upon Ordinary Portland Cement and Slag-Blended Mortars

    Directory of Open Access Journals (Sweden)

    Atta-ur-Rehman

    2018-02-01

    Full Text Available In this study, the effects of titanium dioxide (TiO2 nanoparticles on the sulfate attack resistance of ordinary Portland cement (OPC and slag-blended mortars were investigated. OPC and slag-blended mortars (OPC:Slag = 50:50 were made with water to binder ratio of 0.4 and a binder to sand ratio of 1:3. TiO2 was added as an admixture as 0%, 3%, 6%, 9% and 12% of the binder weight. Mortar specimens were exposed to an accelerated sulfate attack environment. Expansion, changes in mass and surface microhardness were measured. Scanning Electron Microscopy (SEM, Energy Dispersive Spectroscopy (EDS, X-ray Diffraction (XRD, Thermogravimetry Analysis (TGA and Differential Scanning Calorimetry (DSC tests were conducted. The formation of ettringite and gypsum crystals after the sulfate attack were detected. Both these products had caused crystallization pressure in the microstructure of mortars and deteriorated the mortars. Our results show that the addition of nano-TiO2 accelerated expansion, variation in mass, loss of surface microhardness and widened cracks in OPC and slag-blended mortars. Nano-TiO2 containing slag-blended mortars were more resistant to sulfate attack than nano-TiO2 containing OPC mortars. Because nano-TiO2 reduced the size of coarse pores, so it increased crystallization pressure due to the formation of ettringite and gypsum thus led to more damage under sulfate attack.

  8. Characteristics and environmental aspects of slag: a review

    Science.gov (United States)

    Piatak, Nadine M.; Parsons, Michael B.; Seal, Robert R.

    2015-01-01

    Slag is a waste product from the pyrometallurgical processing of various ores. Based on over 150 published studies, this paper provides an overview of mineralogical and geochemical characteristics of different types of slag and their environmental consequences, particularly from the release of potentially toxic elements to water. This chapter reviews the characteristics of both ferrous (steel and blast furnace Fe) and non-ferrous (Ag, Cu, Ni, Pb, Sn, Zn) slag. Interest in slag has been increasing steadily as large volumes, on the order of hundreds of millions of tonnes, are produced annually worldwide. Research on slag generally focuses on potential environmental issues related to the weathering of slag dumps or on its utility as a construction material or reprocessing for secondary metal recovery. The chemistry and mineralogy of slag depend on the metallurgical processes that create the material and will influence its fate as waste or as a reusable product.

  9. Sulphuric Acid Resistant of Self Compacted Geopolymer Concrete Containing Slag and Ceramic Waste

    Directory of Open Access Journals (Sweden)

    Shafiq I.

    2017-01-01

    Full Text Available Malaysia is a one of the developing countries where the constructions of infrastructure is still ongoing, resulting in a high demand for concrete. In order to gain sustainability factors in the innovations for producing concrete, geopolymer concrete containing granulated blast-furnace slag and ceramics was selected as a cement replacement in concrete for this study. Since Malaysia had many ceramic productions and uses, the increment of the ceramic waste will also be high. Thus, a new idea to reuse this waste in construction materials have been tested by doing research on this waste. Furthermore, a previous research stated that Ordinary Portland Cement concrete has a lower durability compared to the geopolymer concrete. Geopolymer binders have been reported as being acid resistant and thus are a promising and alternative binder for sewer pipe manufacture. Lack of study regarding the durability of the geopolymer self-compacting concrete was also one of the problems. The waste will be undergoing a few processes in the laboratory in order to get it in the best form before undergoing the next process as a binder in geopolymer concrete. This research is very significant in order to apply the concept of sustainability in the construction field. In addition, the impact of this geopolymer binder is that it emits up to nine times less CO2 than Portland Cement.

  10. Influence of thermal charge preparation on coke comminution under blast-furnace operating conditions

    Energy Technology Data Exchange (ETDEWEB)

    Shkoller, M.B.; Dinel' t, V.M.; Korchuganova, G.S.; Petrov, V.B.

    1983-01-01

    An investigation is described for the study of structural breakdown of coke by thermochemical action of alkali and alkaline-earth metal vapors under blast furnace operating conditions. Bench-scale test facilities are described in which a pair of coke samples are exposed to the metal vapors then subjected to gasification. Structural strength tests were performed before and after each experiment. Coke samples were obtained in either moist or thermally prepared condition. The value of thermal charge preparation (heat treatment of the coal at 150/sup 0/C in a fluidized bed) was established, since it shifts the pore size distribution to the smaller size, thereby retarding adsorption of the metal vapors. 16 references, 4 figures, 2 tables.

  11. Solid-fluid characteristics at the blast furnace hearth according to the nodal wear model (NWM)

    International Nuclear Information System (INIS)

    Martin, R.; Barbes, M. A.; Barbes, M. F.; Marinas, E.; Ayala, N.; Mochon, J.; Verdeja, L. F.; Garcia, F.

    2009-01-01

    The coke porosity is one of the most important variables that can affect the pig iron production and the lining corrosion. Up to now, the existing bibliography about lining corrosion always connects a deeper wear to an increase in the fluid flow (pig iron) at the blast furnace hearth. However, there is no evidence of any deterministic model that could link, from the theoretical point of view, the following variables: lining corrosion, porosity of dead coke and flow of pig iron at the hearth. Besides justifying the lining corrosion profiles, the Nodal Wear Model (NWM) can be an effective instrument to interpret the coke porosity and the pig iron speed rates that are generated inside the hearth. (Author) 23 refs

  12. Computational Fluid Dynamics (CFD) Modeling for High Rate Pulverized Coal Injection (PCI) to Blast Furnaces

    International Nuclear Information System (INIS)

    Zhou, Chenn

    2008-01-01

    Pulverized coal injection (PCI) into the blast furnace (BF) has been recognized as an effective way to decrease the coke and total energy consumption along with minimization of environmental impacts. However, increasing the amount of coal injected into the BF is currently limited by the lack of knowledge of some issues related to the process. It is therefore important to understand the complex physical and chemical phenomena in the PCI process. Due to the difficulty in attaining trus BF measurements, Computational fluid dynamics (CFD) modeling has been identified as a useful technology to provide such knowledge. CFD simulation is powerful for providing detailed information on flow properties and performing parametric studies for process design and optimization. In this project, comprehensive 3-D CFD models have been developed to simulate the PCI process under actual furnace conditions. These models provide raceway size and flow property distributions. The results have provided guidance for optimizing the PCI process

  13. Computational Fluid Dynamics (CFD) Modeling for High Rate Pulverized Coal Injection (PCI) into the Blast Furnace

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Chenn Zhou

    2008-10-15

    Pulverized coal injection (PCI) into the blast furnace (BF) has been recognized as an effective way to decrease the coke and total energy consumption along with minimization of environmental impacts. However, increasing the amount of coal injected into the BF is currently limited by the lack of knowledge of some issues related to the process. It is therefore important to understand the complex physical and chemical phenomena in the PCI process. Due to the difficulty in attaining trus BF measurements, Computational fluid dynamics (CFD) modeling has been identified as a useful technology to provide such knowledge. CFD simulation is powerful for providing detailed information on flow properties and performing parametric studies for process design and optimization. In this project, comprehensive 3-D CFD models have been developed to simulate the PCI process under actual furnace conditions. These models provide raceway size and flow property distributions. The results have provided guidance for optimizing the PCI process.

  14. Visualisation of a mathematical model of blast furnace operation for distance learning purposes

    Directory of Open Access Journals (Sweden)

    Babich, A.

    2005-12-01

    Full Text Available Advanced educational technologies like Virtual Laboratories are being developed and launched in order to equip customers from higher education institutions, research and industry with efficient tools, supporting their work and operating new skills-training methods. Visual Model "Blast Furnace" based on a mathematical balance model of the blast furnace process has been developed for distance learning (DL purposes. It processes entered parameters and outputs both operating and learning results. The model simulates also sinter and pellets manufacture as well as operation of hot stove. The teacher and learners can interact with each other using software interface which allows to monitor the activity of the learners, answer their questions, and analyse the learning results. The model is an ingredient of the "Virtual Lab Ironmaking".

    Se desarrollan y presentan tecnologías avanzadas de educación, como los Laboratorios Virtuales, para suministrar a los clientes de las instituciones de educación superior, investigación e industria, en apoyo de su trabajo, nuevos y eficientes métodos de operación y técnicas especiales de adiestramiento. Se ha desarrollado el Modelo Visual de "Horno Alto" basado en un modelo matemático del balance del proceso del horno alto, para fines de educación a distancia. Procesa los parámetros de entrada y salida en operación y los resultados de la enseñanza. El modelo también simula la fabricación de sinter y pelets, además de la operación de las estufas. El profesor y alumnos pueden interactuar entre sí usando un software que permite seguir la marcha de la actividad de los alumnos, responder a sus preguntas y analizar los resultados del aprendizaje. El modelo es parte del "Laboratorio Virtual de Fabricación de Arrabio".

  15. Evaluation of Portland cement from X-ray diffraction associated with cluster analysis; Avaliacao de cimento Portland a partir da difracao de raios X associada a analise por agrupamento

    Energy Technology Data Exchange (ETDEWEB)

    Gobbo, Luciano de Andrade, E-mail: luciano.gobbo@panalytical.com [Panalytical Brasil, Sao Paulo, SP (Brazil); Montanheiro, Tarcisio Jose, E-mail: tarcisio.montanheiro@gmail.com [Instituto Geologico, Secretaria de Estado do Meio Ambiente, Sao Paulo, SP (Brazil); Montanheiro, Filipe, E-mail: flpmontanheiro@gmail.com [Universidade Estadual Paulista (LEBAC/UNESP), Rio Claro, SP (Brazil). Departamento de Geologia Aplicada. Lab. de Estudos de Bacias; Sant' Agostino, Lilia Mascarenhas, E-mail: agostino@usp.br [Universidade de Sao Paulo (USP), SP (Brazil). Instituto de Geociencias. Departamento de Geologia Sedimentar e Ambiental

    2013-12-15

    The Brazilian cement industry produced 64 million tons of cement in 2012, with noteworthy contribution of CP-II (slag), CP-III (blast furnace) and CP-IV (pozzolanic) cements. The industrial pole comprises about 80 factories that utilize raw materials of different origins and chemical compositions that require enhanced analytical technologies to optimize production in order to gain space in the growing consumer market in Brazil. This paper assesses the sensitivity of mineralogical analysis by X-ray diffraction associated with cluster analysis to distinguish different kinds of cements with different additions. This technique can be applied, for example, in the prospection of different types of limestone (calcitic, dolomitic and siliceous) as well as in the qualification of different clinkers. The cluster analysis does not require any specific knowledge of the mineralogical composition of the diffractograms to be clustered; rather, it is based on their similarity. The materials tested for addition have different origins: fly ashes from different power stations from South Brazil and slag from different steel plants in the Southeast. Cement with different additions of limestone and white Portland cement were also used. The Rietveld method of qualitative and quantitative analysis was used for measuring the results generated by the cluster analysis technique. (author)

  16. Effect of magnesia on properties and microstructure of alkali-activated slag cement

    Directory of Open Access Journals (Sweden)

    Yong-hao Fang

    2011-12-01

    Full Text Available The effect of magnesia burnt at 800-950°C on the properties, especially the shrinkage, of alkali-activated slag cement (AASC was experimentally studied. Experimental results show that, although adding 4%-8% lightly-burnt magnesia may shorten the setting time and slightly reduce the compressive strength of AASC, it can remarkably reduce the shrinkage of AASC. The results also show that the setting time of AASC with a certain amount of magnesia increases with the burning temperature, and that the flexural and compressive strengths of AASC decrease with the increase of the additive amount of magnesia. Generally, the adverse effect of magnesia decreases with the increase of the burning temperature, and the shrinkage-reducing effect of magnesia increases with the additive amount of magnesia. X-ray diffraction (XRD and scanning electron microscopy (SEM analyses show that some magnesia particles in the hardened AASC paste at a 28-d age remained unhydrated, and that the compactness decreased a little as magnesia was added. We can also conclude that magnesia burnt at 850-950°C can be used to reduce the shrinkage of AASC only when its additive amount does not exceed 8%; otherwise, the setting time may be too short, and the flexural and compressive strengths may severely decrease.

  17. Effect of natural carbonation on the pore structure and elastic modulus of the alkali-activated fly ash and slag pastes

    NARCIS (Netherlands)

    Nedeljkovic, M.; Šavija, B.; Zuo, Y.; Lukovic, M.; Ye, G.

    2018-01-01

    The aim of this paper was to investigate the effect of natural carbonation on the pore structure, and elastic modulus (E-m) of alkali-activated fly ash (FA) and ground granulated blast furnace slag (GBFS) pastes after one year of exposure in the natural laboratory conditions. The chemical changes

  18. Effect of natural carbonation on the pore structure and elastic modulus of the alkali-activated fly ash and slag pastes

    NARCIS (Netherlands)

    Nedeljkovic, M.; Šavija, B.; Zuo, Y.; Lukovic, M.; Ye, G.

    2018-01-01

    The aim of this paper was to investigate the effect of natural carbonation on the pore structure, and elastic modulus (Em) of alkali-activated fly ash (FA) and ground granulated blast furnace slag (GBFS) pastes after one year of exposure in the natural laboratory conditions. The

  19. Performance evaluation of cement stabilized fly ash-GBFS mixes as a highway construction material.

    Science.gov (United States)

    Singh, S P; Tripathy, D P; Ranjith, P G

    2008-01-01

    Fly ash and granulated blast furnace slag (GBFS) are major by-products of thermal and steel plants, respectively. These materials often cause disposal problems and environmental pollution. Detailed laboratory investigations were carried out on cement stabilized fly ash-(GBFS) mixes in order to find out its suitability for road embankments, and for base and sub-base courses of highway pavements. Proctor compaction test, unconfined compressive strength (UCS) test and California Bearing Ratio (CBR) test were conducted on cement stabilized fly ash-GBFS mixes as per the Indian Standard Code of Practice. Cement content in the mix was varied from 0% to 8% at 2% intervals, whereas the slag content was varied as 0%, 10%, 20%, 30% and 40%. Test results show that an increase of either cement or GBFS content in the mixture, results in increase of maximum dry density (MDD) and decrease of optimum moisture content (OMC) of the compacted mixture. The MDD of the cement stabilized fly ash-GBFS mixture is comparably lower than that of similarly graded natural inorganic soil of sand to silt size. This is advantageous in constructing lightweight embankments over soft, compressible soils. An increase in percentage of cement in the fly ash-GBFS mix increases enormously the CBR value. Also an increase of the amount of GBFS in the fly ash sample with fixed cement content improves the CBR value of the stabilized mix. In the present study, the maximum CBR value of compacted fly ash-GBFS-cement (52:40:8) mixture obtained was 105%, indicating its suitability for use in base and sub-base courses in highway pavements with proper combinations of raw materials.

  20. Assessment of strength properties of cemented paste backfill by ultrasonic pulse velocity test.

    Science.gov (United States)

    Yılmaz, Tekin; Ercikdi, Bayram; Karaman, Kadir; Külekçi, Gökhan

    2014-07-01

    Ultrasonic pulse velocity (UPV) test is one of the most popular non-destructive techniques used in the assessment of the mechanical properties of concrete or rock materials. In this study, the effects of binder type/dosage, water to cement ratio (w/c) and fines content (ultrasonic pulse velocity (UPV) of cemented paste backfill (CPB) samples were investigated and correlated with the corresponding unconfined compressive strength (UCS) data. A total of 96 CPB samples prepared at different mixture properties were subjected to the UPV and UCS tests at 7, 14, 28 and 56-days of curing periods. UPV and UCS of CPB samples of ordinary Portland cement (CEM I 42.5 R) and sulphate resistant cement (SRC 32.5) initially increased rapidly, but, slowed down after 14 days. However, UPV and UCS of CPB samples of the blast furnace slag cement (CEM III/A 42.5 N) steadily increased between 7 and 56 days. Increasing binder dosage or reducing w/c ratio and fines content (estimation of the strength of CPB samples. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Research on Reasonable Particle Size of Coal Blends for Blast Furnace Injection: Semi Coke and Bituminous Coal

    Science.gov (United States)

    Wang, Haiyang; Xu, Runsheng; Song, Tengfei; Zhang, Pengcheng

    Semi coke, a byproduct in the chemical industry, is a new fuel for blast furnace injection in China. In this study, semi coke and bitumite were milled into different size, ranged from 0.147mm to under 0.074mm. The content of volatile matter and ash, which affect the combustibility of semi coke, were measured using muffle furnace. The mixture, in which the proportion of coal in different sizes changed, was blend by semi coke and bitumite with different size. Activation energy calculation and the comprehensive combustion characteristic index of all kinds of blends was also discussed. The result obtained by Thermogravimetry -Derivative Thermogravimetry curves indicates that the smaller the size of mixture is, the lower for the characteristic temperature, and the better for its combustibility, Semi coke can be a substitute for anthracite in blast furnace injection.

  2. Similarities between pinch analysis and classical blast furnace analysis methods. Possible improvement by synthesis. Paper no. IGEC-1-004

    International Nuclear Information System (INIS)

    Ryman, C.; Grip, C.-E.; Franck, P.-A.; Wikstrom, J.-O.

    2005-01-01

    Pinch analysis originated at UMIST in the 1970's. It has since then been used as a method for energy analysis and optimisation of industrial systems. The blast furnace process for reducing iron oxide to molten iron is a very important process unit in the metallurgical industry. It is a counter-current shaft process with a wide temperature range and gaseous, solid and liquid phases present in different zones. Because of this the blast furnace acts as a system of different sub-processes rather than a single process. The analysis tools developed to describe the process are in some respects similar to the tools of pinch analysis. The exchange between the two fields of knowledge has yet been negligible. In this paper the methods are described and compared. Problems, possibilities and advantages with an exchange and synthesis of knowledge are discussed. (author)

  3. Development of a Zero-Cement Binder Using Slag, Fly Ash, and Rice Husk Ash with Chemical Activator

    Directory of Open Access Journals (Sweden)

    M. R. Karim

    2015-01-01

    Full Text Available The increasing demand and consumption of cement have necessitated the use of slag, fly ash, rice husk ash (RHA, and so forth as a supplement of cement in concrete construction. The aim of the study is to develop a zero-cement binder (Z-Cem using slag, fly ash, and RHA combined with chemical activator. NaOH, Ca(OH2, and KOH were used in varying weights and molar concentrations. Z-Cem was tested for its consistency, setting time, flow, compressive strength, XRD, SEM, and FTIR. The consistency and setting time of the Z-Cem paste increase with increasing RHA content. The Z-Cem mortar requires more superplasticizer to maintain a constant flow of 110±5% compared with OPC. The compressive strength of the Z-Cem mortar is significantly influenced by the amounts, types, and molar concentration of the activators. The Z-Cem mortar achieves a compressive strength of 42–44 MPa at 28 days with 5% NaOH or at 2.5 molar concentrations. The FTIR results reveal that molecules in the Z-Cem mortar have a silica-hydrate (Si-H bond with sodium or other inorganic metals (i.e., sodium/calcium-silica-hydrate-alumina gel. Therefore, Z-Cem could be developed using the aforementioned materials with the chemical activator.

  4. Choice of technological regimes of a blast furnace operation with injection of hot reducing gases

    Directory of Open Access Journals (Sweden)

    Babich, A. I.

    2002-08-01

    Full Text Available Injection rate of fossil fuels is limited because of drop in the flame temperature in the raceway and problems in the deadman region and the cohesive zone. The next step for obtaining a considerable coke saving, a better operation in the deadman as an well as increase in blast furnace productivity and minimizing the environmental impact due to a decrease in carbon dioxide emmision would be injection by tuyeres of hot reducing gases (HRG which are produced by low grade coal gasification or top gas regenerating. Use of HRG in combination with high pulverized coal inyection PCI rate and oxigen enrichment in the blast could allow to keep and to increase the competitiveness of the blast furnace process. Calculations using a mathematical model show that the HRG injection in combination with pulverized coal (PC and enriching blast with oxigen can provide an increase in PC rate up to 300-400 kg/tHM and a rise in the furnace productivity by 40-50 %. Blast furnace operation with full oxigen blast (100 % of process oxigen with the exception for the hot blast is possible when HRG is injected.

    La tasa de inyección de combustibles fósiles está limitada a causa de la caída de la temperatura de llama en el raceway (cavidad frente a las toberas y a problemas en la región del "hombre muerto" y en la zona cohesiva. La inyección por tobera de gases reductores calientes (GRC, que se producen por gasificación de carbón de bajo grado o generación de gas de tragante, será la próxima etapa para lograr un considerable ahorro adicional de coque, una zona del "hombre muerto" bien definida, además de un aumento en la productividad del horno alto y para minimizar el impacto ambiental debido a una disminución de la emisión de dióxido de carbono. El uso de GRC en combinación con una tasa elevada de inyección de carbón pulverizado (ICP con viento enriquecido en oxígeno, podrá permitir mantener y aumentar la competitividad del proceso del horno

  5. Risk management of energy efficiency projects in the industry - sample plant for injecting pulverized coal into the blast furnaces

    OpenAIRE

    Jovanović Filip P.; Berić Ivana M.; Jovanović Petar M.; Jovanović Aca D.

    2016-01-01

    This paper analyses the applicability of well-known risk management methodologies in energy efficiency projects in the industry. The possibilities of application of the selected risk management methodology are demonstrated within the project of the plants for injecting pulverized coal into blast furnaces nos. 1 and 2, implemented by the company US STEEL SERBIA d.o.o. in Smederevo. The aim of the project was to increase energy efficiency through the reductio...

  6. Off-gas dust in an experimental blast furnace:Part 1: Characterization of flue dust, sludge and shaft fines

    OpenAIRE

    Leimalm, Ulrika; Lundgren, Maria; Sundqvist Ökvist, Lena; Björkman, Bo

    2010-01-01

    In blast furnace (BF) ironmaking, efforts are made to decrease coke consumption, which can be done by increasing the pulverized coal injection rate (PCR). This will cause changes in in-furnace reduction conditions, burden distribution, demands on raw material strength, etc. In order to maintain stable operation, but also to obtain low amounts of material losses through the off-gas, it is important to understand fines generation and behaviour in the BF. Off-gas dust and shaft fines generated i...

  7. Results of tuyere coke sampling with regard to application of appropriate coke strength after reaction (CSR) for a blast furnace

    OpenAIRE

    Shiau J-S.; Ko Y-C.; Ho C-K.; Hung M-T.

    2017-01-01

    Raising pulverized coal injection (PCI) will decrease coke rate, but increase the residence time of coke and abrasion in the blast furnace (BF). Thus, insufficient coke strength will generate more coke fines in the lower BF and result in lower permeability and production of hot metal (HM). For understanding the behavior of coke at various HM productivities, a tuyere coke sampler was used to collect the coke samples for measuring the coke strength. Firstly, ...

  8. The hydration of slag, part 1: reaction models for blended cement

    NARCIS (Netherlands)

    Chen, Wei; Brouwers, Jos

    2007-01-01

    Reaction models are proposed to quantify the hydration products and to determine the composition of C–S–H from alkali-activated slags (AAS). Products of the slag hydration are first summarized from observations in literature. The main hydration products include C–S–H, hydrotalcite, hydrogarnet, AFm

  9. Modelling of Coke Layer Collapse during Ore Charging in Ironmaking Blast Furnace by DEM

    Science.gov (United States)

    Narita, Yoichi; Mio, Hiroshi; Orimoto, Takashi; Nomura, Seiji

    2017-06-01

    A technical issue in an ironmaking blast furnace operation is to realize the optimum layer thickness and the radial distribution of burden (ore and coke) to enhance its efficiency and productivity. When ore particles are charged onto the already-embedded coke layer, the coke layer-collapse phenomenon occurs. The coke layer-collapse phenomenon has a significant effect on the distribution of ore and coke layer thickness in the radial direction. In this paper, the mechanical properties of coke packed bed under ore charging were investigated by the impact-loading test and the large-scale direct shear test. Experimental results show that the coke particle is broken by the impact force of ore charging, and the particle breakage leads to weaken of coke-layer strength. The expression of contact force for coke in Discrete Element Method (DEM) was modified based on the measured data, and it followed by the 1/3-scaled experiment on coke's collapse phenomena. Comparing a simulation by modified model to the 1/3-scaled experiment, they agreed well in the burden distribution.

  10. Modelling of Coke Layer Collapse during Ore Charging in Ironmaking Blast Furnace by DEM

    Directory of Open Access Journals (Sweden)

    Narita Yoichi

    2017-01-01

    Full Text Available A technical issue in an ironmaking blast furnace operation is to realize the optimum layer thickness and the radial distribution of burden (ore and coke to enhance its efficiency and productivity. When ore particles are charged onto the already-embedded coke layer, the coke layer-collapse phenomenon occurs. The coke layer-collapse phenomenon has a significant effect on the distribution of ore and coke layer thickness in the radial direction. In this paper, the mechanical properties of coke packed bed under ore charging were investigated by the impact-loading test and the large-scale direct shear test. Experimental results show that the coke particle is broken by the impact force of ore charging, and the particle breakage leads to weaken of coke-layer strength. The expression of contact force for coke in Discrete Element Method (DEM was modified based on the measured data, and it followed by the 1/3-scaled experiment on coke’s collapse phenomena. Comparing a simulation by modified model to the 1/3-scaled experiment, they agreed well in the burden distribution.

  11. Study of the reduction mechanism of ironsands with addition of blast furnace bag dust

    Science.gov (United States)

    Xing, Xiangdong; Chen, Yunfei; Liu, Yiran

    2018-02-01

    To improve the reduction properties of ironsands carbon-containing briquettes, the behavior of ironsand during reduction by the addition of blast furnace bag dust (BFBD) is studied using a high temperature resistance furnace, X-ray diffraction (XRD) analysis and scanning electron microscopy. Additionally, the reduction mechanism is discussed in this study. The results showed that the reduction level and compressive strength of ironsand carbon-containing briquettes could be promoted by increasing the proportion of BFBD. When the addition rate of BFBD was 31.25%, the metallization rate and compressive strength increased from 82.1% and 21.5 N/a to 91.4% and 172.5 N/a, respectively. Metallic iron reduced from BFBD particles favored the carbon gasification reaction, which enhanced the internal CO concentration, and then promoted the FeTiO3 reduction to Fe in ironsand. Meanwhile, a large amount of the liquid phase generated during the reduction process also favored Fe2+ diffusion, spread of iron joined crystals and the growth of crystals, which resulted in the improvement of the compressive strength of the ironsand carbon-containing briquettes.

  12. Dynamic leaching behavior of geogenic As in soils after cement-based stabilization/solidification.

    Science.gov (United States)

    Li, Jiang-Shan; Wang, Lei; Tsang, Daniel C W; Beiyuan, Jingzi; Poon, Chi Sun

    2017-12-01

    Cement-based stabilization/solidification (S/S) is a practical treatment approach for hazardous waste with anthropogenic As sources; however, its applicability for geogenic As-containing soil and the long-term leaching potential remain uncertain. In this study, semi-dynamic leaching test was performed to investigate the influence of S/S binders (cement blended with fuel ash (FA), furnace bottom ash (FBA), or ground granulated blast furnace slag (GGBS)) on the long-term leaching characteristics of geogenic As. The results showed that mineral admixtures with higher Ca content and pozzolanic activity were more effective in reducing the leached As concentrations. Thus, cement blended with FBA was inferior to other binders in suppressing the As leaching, while 20% replacement of ordinary Portland cement by GGBS was considered most feasible for the S/S treatment of As-containing soils. The leachability of geogenic As was suppressed by the encapsulation effect of solidified matrix and interlocking network of hydration products that were supported by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) results. The long-term leaching of geogenic As from the monolithic samples was diffusion-controlled. Increasing the Ca content in the samples led to a decrease in diffusion coefficient and an increase in feasibility for "controlled utilization" of the S/S-treated soils.

  13. Simulation of expansion in cement based materials subjected to external sulfate attack

    Directory of Open Access Journals (Sweden)

    O.A. Hodhod

    2014-03-01

    Full Text Available The standard test for length change in hydraulic-cement mortars exposed to sulfate solution, ASTM C1012-95, has been widely used by researchers to study the sulfate resistance of cement based materials. However, there are deficiencies in this test method including lengthy measuring period, insensitivity of the measurement tool to sulfate attack, effect of curing and pH change. So, in this study, a model will be built by artificial neural networks (ANNs to simulate this test and overcome these defects. This model will deal with different types of cement in the presence of blast-furnace slag (GGBFS or fly ash (PFA. From the results of simulations, it is possible to understand the impact of cement chemistry and these two types of additions on resistance of sulfate attack more readily, faster, and accurately. Such an understanding improves the decision making process in every stage of construction and maintenance and will help in better administration of resources.

  14. EFFECT OF REACTIVE MAGNESIUM OXIDE ON PROPERTIES OF ALKALI ACTIVATED SLAG GEOPOLYMER CEMENT PASTES

    Directory of Open Access Journals (Sweden)

    H. A. Abdel-Gawwad

    2015-03-01

    Full Text Available The effect of different proportions and different reactivities of MgO on the drying shrinkage and compressive strength of alkali activated slag pastes (AAS has been investigated. The slag was activated by 6 wt.% sodium hydroxide and liquid sodium silicate at ratio of 3:3 (wt.. The different reactivities of MgOs were produced from the calcination of hydromagnesite at different temperatures (550, 1000, 1250 C. The results showed that the reactivity of magnesium oxide decreases with increasing the calcination temperature. Also, the drying shrinkage of AAS was reduced by the replacement of slag with MgOs. The highly reactive MgO accelerated the hydration of AAS at early ages. The replacement of slag with 5% MgO550 increased one day compressive strength by ~26 % while MgO1250 had little effect. A significant increase in strength was observed after 7 days in case of replacement of slag with 5 % MgO1250. The MgO reacts with slag to form hydrotalcite likephases (Ht as detected by XRD, FTIR spectroscopy, TGA/DTG analysis and SEM.

  15. Durabilité de pâtes de ciments contenant du laitier d’El Hadjar conservées dans des milieux agressifs et à des températures de climat chaud Durability of cement pastes containing slag of El Hajar preserved in aggressive environments and at temperatures of hot climate

    Directory of Open Access Journals (Sweden)

    Clastres P.

    2012-09-01

    Full Text Available En vue d’améliorer la durabilité des bétons durcis, notamment vis à vis des eaux agressives telles que eau de mer, eaux sulfatées, …et dans le cas d’une température de conservation de climat chaud (20 à 40 °C, nous proposons d’utiliser des ciments contenant 20 % (CPJ, CEM II B ou 50 % (CHF, CEM III A de laitier granulé moulu de haut fourneau d’El Hadjar. Les essais sont réalisés sur pâte pure afin de mieux suivre parallèlement l’évolution minéralogique des mélanges durcis par analyse au moyen de la diffraction des rayons X. Les indicateurs de durabilités choisis et suivis de 1 jour à 1 an sont les variations dimensionnelles et les résistances mécaniques en compression simple. Le pH des solutions, liés notamment à la fréquence de renouvellement des bains, apparaît comme un paramètre important d’agressivité. Les résultats obtenus permettent notamment de mettre en évidence l’effet bénéfique sur la durabilité aux sulfates d’un ajout aux ciments de laitier granulé ainsi qu’une certaine agressivité pour ces mêmes ciments d’une conservation en eau de mer à 20°C. Une température de climat chaud (40°C ne modifie pas fondamentalement ces résultats. To improve the durability of hardened concrete, especially against aggressive water such as sea water, sulphated, … and in the case of a conservation temperature of hot climate (20 to 40°C we propose the use of cements containing 20% (CPJ CEM II B or 50% (CHF, CEM III A granulated blast furnace slag of El Hajar. The tests are performed on cement paste in order to better follow parallely the mineralogical evolution of mixtures cured by analysis of X-ray diffraction. The Indicators of sustainability selected and followed from 1 day to 1 year, are the dimensional variation and the compressive strength simple. The pH of the solutions, especially related to the renewal frequency of the baths, appears as an important parameter of aggressiveness. The

  16. Experimental study on workability of alkali activated fly ash and slag-based geopolymer concretes

    NARCIS (Netherlands)

    Arbi, K.A.; Nedeljkovic, M.; Zuo, Y.; Grunewald, S.; Keulen, A.; Ye, G.

    2015-01-01

    This paper presents an investigation on workability and strength of geopolymer concrete made of fly ash (FA), blast furnace slag (BFS) and a multicompound activator of Na2SiO3 and NaOH solutions. The FA/BFS ratios were 100:0, 70:30, 60:40, 50:50, 40:60, 30:70 and 0:100. The workability of geopolymer

  17. Charcoal injection in blast furnaces (Bio-PCI: CO2 reduction potential and economic prospects

    Directory of Open Access Journals (Sweden)

    Cristobal Feliciano-Bruzual

    2014-07-01

    Full Text Available The steel industry is under pressure to reduce its CO2 emissions, which arise from the use of coal. In the long-term, the injection of pulverized particles of charcoal from biomass through blast furnace tuyeres, in this case called Bio-PCI, is an attractive method from both an environmental and metallurgical viewpoint. The potential of Bio-PCI has been assessed in terms of its CO2 abatement potential and economic viewpoint. A cost objective function has been used to measure the impact of biochar substitution in highly fuel-efficient BF among the top nine hot metal producers; estimations are based on the relevant cost determinants of ironmaking. This contribution aims to shed light on two strategic questions: Under what conditions is the implementation of Bio-PCI economically attractive? Additionally, where is such a techno-economic innovation likely to be taken up the earliest? The results indicate the potential for an 18–40% mitigation of CO2. Findings from the economic assessment show that biochar cannot compete with fossil coal on price alone; therefore, a lower cost of biochar or the introduction of carbon taxes will be necessary to increase the competitiveness of Bio-PCI. Based on the current prices of raw materials, electricity and carbon taxes, biochar should be between 130.1 and 236.4 USD/t and carbon taxes should be between 47.1 and 198.7 USD/t CO2 to facilitate the substitution of Bio-PCI in the examined countries. In regard to implementation, Brazil, followed by India, China and the USA appeared to be in a better position to deploy Bio-PCI.

  18. Low pH Cements

    Energy Technology Data Exchange (ETDEWEB)

    Savage, David; Benbow, Steven [Quintessa Ltd., Henley-on-Thames (United Kingdom)

    2007-05-15

    The development of low-pH cements for use in geological repositories for radioactive waste stems from concerns over the potential for deleterious effects upon the host rock and other EBS materials (notably bentonite) under the hyperalkaline conditions (pH > 12) of cement pore fluids. Low pH cement (also known as low heat cement) was developed by the cement industry for use where large masses of cement (e.g. dams) could cause problems regarding heat generated during curing. In low pH cements, the amount of cement is reduced by substitution of materials such as fly ash, blast furnace slag, silica fume, and/or non-pozzolanic silica flour. SKB and Posiva have ruled out the use of blast furnace slag and fly-ash and are focusing on silica fume as a blending agent. Currently, no preferred composition has been identified by these agencies. SKB and Posiva have defined a pH limit {<=} 11 for cement grout leachates. To attain this pH, blending agents must comprise at least 50 wt % of dry materials. Because low pH cement has little, or no free portlandite, the cement consists predominantly of calcium silicate hydrate (CSH) gel with a Ca/Si ratio {<=} 0.8. Although there are potential implications for the performance of the spent fuel and cladding due to the presence of hyperalkaline fluids from cement, the principal focus for safety assessment lies with the behaviour of bentonite. There are a number of potential constraints on the interaction of hyperalkaline cement pore fluids with bentonite, including mass balance, thermodynamic issues, mass transport, and kinetics, but none of these is likely to be limiting if conventional OPC cements are employed in repository construction. Nevertheless: Low-pH cements may supply approximately 50 % less hydroxyl ions than conventional OPC for a given volume of cement, but mass balance constraints are complicated by the uncertainty concerning the type of secondary minerals produced during cement-bentonite interaction. The change of aqueous

  19. Low pH Cements

    International Nuclear Information System (INIS)

    Savage, David; Benbow, Steven

    2007-05-01

    The development of low-pH cements for use in geological repositories for radioactive waste stems from concerns over the potential for deleterious effects upon the host rock and other EBS materials (notably bentonite) under the hyperalkaline conditions (pH > 12) of cement pore fluids. Low pH cement (also known as low heat cement) was developed by the cement industry for use where large masses of cement (e.g. dams) could cause problems regarding heat generated during curing. In low pH cements, the amount of cement is reduced by substitution of materials such as fly ash, blast furnace slag, silica fume, and/or non-pozzolanic silica flour. SKB and Posiva have ruled out the use of blast furnace slag and fly-ash and are focusing on silica fume as a blending agent. Currently, no preferred composition has been identified by these agencies. SKB and Posiva have defined a pH limit ≤ 11 for cement grout leachates. To attain this pH, blending agents must comprise at least 50 wt % of dry materials. Because low pH cement has little, or no free portlandite, the cement consists predominantly of calcium silicate hydrate (CSH) gel with a Ca/Si ratio ≤ 0.8. Although there are potential implications for the performance of the spent fuel and cladding due to the presence of hyperalkaline fluids from cement, the principal focus for safety assessment lies with the behaviour of bentonite. There are a number of potential constraints on the interaction of hyperalkaline cement pore fluids with bentonite, including mass balance, thermodynamic issues, mass transport, and kinetics, but none of these is likely to be limiting if conventional OPC cements are employed in repository construction. Nevertheless: Low-pH cements may supply approximately 50 % less hydroxyl ions than conventional OPC for a given volume of cement, but mass balance constraints are complicated by the uncertainty concerning the type of secondary minerals produced during cement-bentonite interaction. The change of aqueous

  20. Thermodynamic analysis of the partial oxidation of coke oven gas for indirect reduction of iron oxides in a blast furnace

    International Nuclear Information System (INIS)

    Chen, Wei-Hsin; Hsu, Chih-Liang; Du, Shan-Wen

    2015-01-01

    The partial oxidation of a COG (coke oven gas) in a blast furnace is examined in this work using thermodynamic analysis. LTIR and HTIR (Low-temperature and high-temperature indirect reduction) of iron oxides in a blast furnace are also studied. The influences of the reaction temperature, M/H (methane-to-hematite) ratio, and O/F (oxygen-to-fuel) ratio on CH 4 conversion and iron oxide reduction are examined. Within the investigated ranges of the parameters, a higher reaction temperature is conducive to CH 4 conversion, while at least 97.64% of Fe 2 O 3 is reduced. In LTIR, Fe 3 O 4 is the prime product, with a high level of solid carbon formation. The entire LTIR reaction is characterized by exothermic behavior, so that no additional heat is required to trigger COG partial oxidation and IR. In HTIR, increasing the reaction temperature facilitates CO-based IR and suppresses H 2 -based IR. A higher temperature produces more Fe, so as to enhance the iron oxide reduction reactions; meanwhile, the FeO reduction is governed by H 2 and CH 4 . When the reaction temperature is higher than 800 °C and the M/H ratio is lower than unity, a heat supply is required to drive HTIR. The O/F ratio in LTIR and HTIR should be controlled below 2 to retard carbon formation and drive iron oxide reduction. - Highlights: • Direct partial oxidation of coke oven gas in blast furnace is analyzed thermodynamically. • A higher reaction temperature is conducive to CH 4 conversion and syngas production. • At least 97.64% of Fe 2 O 3 is converted. • The low-temperature indirect reduction is characterized by exothermic behavior. • The oxygen-to-fuel molar ratio in indirect reduction should be controlled below 2

  1. Simultaneous utilization of neutrons and γ-rays from 252Cf for condition measurement inside a blast furnace

    International Nuclear Information System (INIS)

    Shirakawa, Yoshiyuki; Tominaga, Hiroshi.

    1997-01-01

    This paper describes the possibility of the realization of a multi-function radiation gauge to meet the requirement for more precise and stable control of a blast furnace. A basic concept of the gauge is to measure some quantities with simultaneous use of multi-radiations of neutrons and γ-rays, and to obtain multi-types of information on material flow and gas flow representing the conditions inside the blast furnace. The prototype gauge was assembled and examined which consisted of a radiation source of 252 Cf (3.7 MBq), neutron moderator, lead shield, a bismuth germanate detector, stainless casing and a control unit. Laboratory experiments showed that the gauge could measure the quantities to be essential to estimate the blast furnace conditions. In practice, it clearly distinguished between iron ore and coke layers, and at the same time measured bulk density (1.0-1.5 g/cm 3 ) of iron contained in iron ore by counting thermal neutron capture γ-rays (6.5-8.5 MeV) from iron. It also gave the information on material bulk density (0.5-2.5 g/cm 3 ) by detecting Compton scattered γ-rays (1.0-1.5 MeV) from material, i.e. iron ore and coke. The relative accuracies in the measurement of iron bulk density and material bulk density were estimated to be within 1 and 4% in 300 s counting time, respectively. The possibility of the gauge has been proved and the on-line trial will be expected in the near future. (author)

  2. Rheological Properties of Cemented Tailing Backfill and the Construction of a Prediction Model

    Directory of Open Access Journals (Sweden)

    Liu Lang

    2015-04-01

    Full Text Available Workability is a key performance criterion for mining cemented tailing backfill, which should be defined in terms of rheological parameters such as yield stress and plastic viscosity. Cemented tailing backfill is basically composed of mill tailings, Portland cement, or blended cement with supplementary cement material (fly ash and blast furnace slag and water, among others, and it is important to characterize relationships between paste components and rheological properties to optimize the workability of cemented tailing backfill. This study proposes a combined model for predicting rheological parameters of cemented tailing backfill based on a principal component analysis (PCA and a back-propagation (BP neural network. By analyzing experimental data on mix proportions and rheological parameters of cemented tailing backfill to determine the nonlinear relationships between rheological parameters (i.e., yield stress and viscosity and mix proportions (i.e., solid concentrations, the tailing/cement ratio, the specific weight, and the slump, the study constructs a prediction model. The advantages of the combined model were as follows: First, through the PCA, original multiple variables were represented by two principal components (PCs, thereby leading to a 50% decrease in input parameters in the BP neural network model, which covered 98.634% of the original data. Second, in comparison to conventional BP neural network models, the proposed model featured a simpler network architecture, a faster training speed, and more satisfactory prediction performance. According to the test results, any error between estimated and expected output values from the combined prediction model based on the PCA and the BP neural network was within 5%, reflecting a remarkable improvement over results for BP neural network models with no PCA.

  3. Rheological Properties of Cemented Tailing Backfill and the Construction of a Prediction Model

    Science.gov (United States)

    Lang, Liu; Song, KI-IL; Lao, Dezheng; Kwon, Tae-Hyuk

    2015-01-01

    Workability is a key performance criterion for mining cemented tailing backfill, which should be defined in terms of rheological parameters such as yield stress and plastic viscosity. Cemented tailing backfill is basically composed of mill tailings, Portland cement, or blended cement with supplementary cement material (fly ash and blast furnace slag) and water, among others, and it is important to characterize relationships between paste components and rheological properties to optimize the workability of cemented tailing backfill. This study proposes a combined model for predicting rheological parameters of cemented tailing backfill based on a principal component analysis (PCA) and a back-propagation (BP) neural network. By analyzing experimental data on mix proportions and rheological parameters of cemented tailing backfill to determine the nonlinear relationships between rheological parameters (i.e., yield stress and viscosity) and mix proportions (i.e., solid concentrations, the tailing/cement ratio, the specific weight, and the slump), the study constructs a prediction model. The advantages of the combined model were as follows: First, through the PCA, original multiple variables were represented by two principal components (PCs), thereby leading to a 50% decrease in input parameters in the BP neural network model, which covered 98.634% of the original data. Second, in comparison to conventional BP neural network models, the proposed model featured a simpler network architecture, a faster training speed, and more satisfactory prediction performance. According to the test results, any error between estimated and expected output values from the combined prediction model based on the PCA and the BP neural network was within 5%, reflecting a remarkable improvement over results for BP neural network models with no PCA.

  4. Slag melt granulation and factors affecting the quality of Granulated slag

    Directory of Open Access Journals (Sweden)

    Володимир Петрович Кравченко

    2015-10-01

    Full Text Available An analysis of the state of slags recycling in foreign countries was carried out. A modern principle was put forward in the article: blast furnace is an apparatus for manufacturing of two basic types of products : cast iron and slag. Granulation, as the primary recycling of slag melt fixes the structure with certain properties at rapid cooling. An analysis of the existing methods of granulation was carried out and factors influencing the quality of granular slag were determined, as well as the ways of obtaining granular slag with the required physical and mechanical characteristics. The main factors of granulated slags quality, employed for manufacturing of binding materials are chemical composition and the structure of fine granulated particles. All wet methods of granulation are characterized by high humidity of granulated slag, its value reaching 24,5%, due to increase in granules’ porosity. Real options for reducing humidity of granulated slag may include: development of the process of granulation, ensuring manufacturing of products with increased density and low content of fine fractions, dehydration of slag in high bunkers and stacks at sufficient soaking time and slag blowdown with a stream moving downwards. Using mechanical granulators and gaseous energy carriers (air for melt’s dispersion is an efficient way of reducing water consumption for granulation (semi-dry or dry methods of granulation. It also makes it possible to reduce r consumption of water, supplied for granulation from 3,0 to 0,7-1,5m3/min. Application of air blast for melt’s dispersion influences its fractional composition and grain shape in the slag: the content of the fraction less than 1,25mm reduces to 49,1%, as compared to conventional 92,8%. The content of spherical grains is with tough surface is 33%, it promoting reduction of residual humidity of granulated slag. Thus, application of air blast for granulation of slags is an efficient way of obtaining high

  5. Immobilisation in cement of ion exchange resins arising from the purification of reagents used for the decontamination of reactor circuits

    International Nuclear Information System (INIS)

    Donoghue, S.J.; Howard, C.G.; Lee, D.J.

    1987-06-01

    An account of the annual decontaminations undertaken on the SGHWR at Winfrith is given with reasons for changing from Citrox reagents to LOMI plus the effects of using nitric acid permanganate solution as a preoxidising agent. Safe disposal of these reagents after use is a problem concerning many water cooled reactor operators. A brief review of the various methods of disposal is given. The proposed method of disposing of LOMI wastes generated at Winfrith is to remove the activity onto ion exchange resins then immobilize them in a cement matrix. Duolite C225 (a cross linked polystyrene with sulphonic acid functional groups) has been identified as a suitable ion exchanger. Duolite C225 in the sodium form can be successfully immobilised in blended cement systems. The formulation which appears acceptable is manufactured from a 9 to 1 blend of Blast Furnace Slag and Ordinary Portland Cement, containing 40% ion exchange resin by weight, in the form of a slurry. The product has adequate strength for handling and shows little dimensional change with time. Experiments show that above 50% waste loading the product becomes unstable and its strength is unacceptably low. Changes in the metal cation have shown little effect on the properties of the product. Increasing the waste loading appears to have little effect on the hydration rate of the product. Preliminary calculations show that a volume reduction factor of 4 is obtained by taking the active LOMI effluent, removing the activity onto the Duolite C225 and then immobilising in cement. (author)

  6. 1D Compressibility of DMS Treated With Cement-GGBS Blend

    Directory of Open Access Journals (Sweden)

    Kaliannan Suaathi

    2017-01-01

    Full Text Available Great quantities of dredged marine soils (DMS have been produced from the maintenance of channels, anchorages and for harbour development. DMS have the potential to pose ecological and human health risks and it is also considered as a geowaste. Malaysia is moving towards the sustainability approach and one of the key factors to achieve it is to reduce waste. Thus, this geowaste should be generated as a new resource to substitute soil for civil works such as for land reclamation and backfilling. This shows the improved settlement of consolidation in treated DMS. DMS is referred to as a cohesive soil which includes clayey silt, sandy clay, silty clay and organic clay. This type of soil has low strength and high compressibility. The objectives were achieved through literature review analysis and also laboratory test which was one dimensional oedometer test. On the other hand, treated DMS with more ground granulated blast furnace slag (GGBS gives a lower settlement compared to specimen with higher percentage of cement in a treated soil. Thus this shows that cement content can be reduced in soil solidification when GGBS is added. The optimum binder ratio found was 3:7 where 3 is cement and 7 is GGBS.

  7. Effect of fly ash on the hydration process in cemented paste backfill at early stages

    Energy Technology Data Exchange (ETDEWEB)

    Simon, D.; Grabinsky, M.W. [Toronto Univ., ON (Canada). Dept. of Civil Engineering

    2009-07-01

    Cemented paste backfill (CPB) is a sustainable backfilling technique used in underground mining operations that ensures ground stabilization. The technique uses mine waste for filling the voids created by underground mining. Compared to conventional backfilling technologies, CPB has the advantage of rapid transport to the stopes; shorter turn-around cycle time; elimination of the drainage barricades in the CPB-filled stopes; and diversion of mine waste from surface disposal sites to underground stopes. Partial replacement of Portland cement with fly ash or ground blast furnace slag, can significantly reduce production costs and improve the performance of typical CPBs. This paper studied the effect of fly ash on the hydration process in CPB during the early stages of hydration using non-destructive, electromagnetic (EM) wave-based techniques. The study showed that the use of fly ash in Portland cement delayed the hydration process, and that the delay was proportional to the replacement level. At later onset times, the fly ash particles enhanced the hydration process by providing additional ions that contributed to the formation of hydration products and ultimately increased the mechanical strength of CPB. The EM test results on CPB obtained in the controlled laboratory environment were compared with in situ test results obtained in an actual backfilled test stope. The EM-wave based techniques were found to be sensitive to paste composition, including binder content, binder type and water content of the paste. 16 refs., 3 tabs., 6 figs.

  8. Application of Iranian natural zeolite and blast furnace slag as slow sand filters media for water softening

    Directory of Open Access Journals (Sweden)

    Ali Abdolahnejad

    2014-01-01

    Conclusions: It is concluded from this study that modified filter media, SMF and ZMF, are very good options for total hardness and turbidity removals in communities that have some problem with this parameter.

  9. Identification of Phase Composition of Binders from Alkali-Activated Mixtures of Granulated Blast Furnace Slag and Fly Ash

    Czech Academy of Sciences Publication Activity Database

    Vlček, J.; Drongová, L.; Topinková, M.; Matějka, V.; Kukutschová, J.; Vavro, Martin; Tomková, V.

    2014-01-01

    Roč. 58, č. 1 (2014), s. 79-88 ISSN 0862-5468 Institutional support: RVO:68145535 Keywords : binders * alkali activation * hydration products Subject RIV: JM - Building Engineering Impact factor: 0.435, year: 2014 http://www.ceramics-silikaty.cz/2014/pdf/2014_01_079.pdf

  10. BIO-PCI, Charcoal injection in Blast Furnaces: State of the art and economic perspectives

    Directory of Open Access Journals (Sweden)

    Feliciano-Bruzual, C.

    2013-12-01

    Full Text Available The injection of grinded particles of charcoal through the tuyeres in Blast Furnaces, here coined Bio-PCI, presents as an attractive and plausible alternative to significantly reduce the CO2 emissions generated during hot metal production. In this contribution a summary of the technological fundaments, benefits and limitations of the incorporation of Bio-PCI is presented. Additionally the principal economic challenges of renewables fuel in ironmaking are exposed, with especial interest in the main productions costs of charcoal making. In this sense, a strategic question arises: can the residual biomass drive the emergence of Bio-PCI?, our analysis leads to conclude that the use of residual biomass (e.g. agricultural and forestry residues may significantly reduce the production cost in 120-180 USD/t in comparison to primary woods sources, this naturally increment the economical attractiveness of Bio-PCI substitution.La inyección de carbón vegetal por toberas en Altos Hornos, aqui denominada Bio-PCI, se presenta como una forma atractiva y realista de reducir significativamente las emisiones de CO2 generadas durante la producción de arrabio. En esta contribución se presenta un resumen de los fundamentos tecnológicos, los beneficios y las limitaciones de la incorporación de la tecnología del Bio-PCI. Adicionalmente se exponen los retos económicos que enfrentan los combustibles renovables a los fósiles, con especial interés en los principales costos de producción del carbón vegetal. En este sentido se plantea una pregunta estratégica: ¿puede la biomasa residual impulsar el desarrollo de la Bio-PCI?. Nuestro análisis conlleva a concluir que la utilización de biomasa residual (residuos forestales y agrícolas puede reducir sensiblemente el costo del carbón vegetal entre 120-180 USD/t en comparación con biomasa primaria, incrementando su competitividad frente al carbón mineral.

  11. Risk management of energy efficiency projects in the industry - sample plant for injecting pulverized coal into the blast furnaces

    Directory of Open Access Journals (Sweden)

    Jovanović Filip P.

    2016-01-01

    Full Text Available This paper analyses the applicability of well-known risk management methodologies in energy efficiency projects in the industry. The possibilities of application of the selected risk management methodology are demonstrated within the project of the plants for injecting pulverized coal into blast furnaces nos. 1 and 2, implemented by the company US STEEL SERBIA d.o.o. in Smederevo. The aim of the project was to increase energy efficiency through the reduction of the quantity of coke, whose production requires large amounts of energy, reduction of harmful exhaust emission and increase productivity of blast furnaces through the reduction of production costs. The project was complex and had high costs, so that it was necessary to predict risk events and plan responses to identified risks at an early stage of implementation, in the course of the project design, in order to minimise losses and implement the project in accordance with the defined time and cost limitations. [Projekat Ministarstva nauke Republike Srbije, br. 179081: Researching contemporary tendencies of strategic management using specialized management disciplines in function of competitiveness of Serbian economy

  12. Reference materials for ratio of moisture content and bulk density of blast furnace coke for neutron moisture and density meters: development and use experience

    Directory of Open Access Journals (Sweden)

    V. D. Savelov

    2016-01-01

    Full Text Available The article deals with reference materials for moisture and bulk density of blast furnace coke for graduation of neutron moisture and density meters. Reference materials are produced from substances and materials which element content is identical to coke elemental content coke.

  13. Using a Mathematical Model of Counter-Current Flow in a Blast Furnace to Evaluate Reducibility of Iron-Ore-Bearing Raw Materials

    Czech Academy of Sciences Publication Activity Database

    Pustějovská, P.; Tůma, J.; Staněk, Vladimír; Křišťál, Jiří; Jursová, s.; Bilík, J.

    2015-01-01

    Roč. 86, č. 4 (2015), s. 320-328 ISSN 1611-3683 Institutional support: RVO:67985858 Keywords : blast furnace * ore burden reducibility * kinetic model Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.021, year: 2015

  14. TRP0033 - PCI Coal Combustion Behavior and Residual Coal Char Carryover in the Blast Furnace of 3 American Steel Companies during Pulverized Coal Injection (PCI) at High Rates

    Energy Technology Data Exchange (ETDEWEB)

    Veena Sahajwalla; Sushil Gupta

    2005-04-15

    Combustion behavior of pulverized coals (PC), gasification and thermal annealing of cokes were investigated under controlled environments. Physical and chemical properties of PCI, coke and carbon residues of blast furnace dust/sludge samples were characterized. The strong influence of carbon structure and minerals on PCI reactivity was demonstrated. A technique to characterize char carryover in off gas emissions was established.

  15. Coke, char and organic waste behaviour in the blast furnace with high injection rate

    Directory of Open Access Journals (Sweden)

    Gudenau, H. W.

    2003-10-01

    Full Text Available Blast furnace operation with low coke rate, high amount of auxiliary hydrocarbons and use of nut coke causes a change in coke quality requirements. In particular, not burned in the raceway residues of injected substances (char and ash can influence the coke behaviour. Therefore combustion efficiency of various organic wastes with and without pulverized coal injection (PCI and coal char has been investigated under the raceway simulation conditions. Mixing of various substances improves their combustion efficiency. Study on coke gasification by carbon dioxide in the presence of char showed that with the increase of char concentration, coke strength reduction becomes smaller. The reactivity of char with CO2 is higher than that of coke. Therefore char is consumed preferentially. In presence of injected char, total pore volume in coke and its wear resistance were increased. Coke reactivity and microstructure in the presence of various kinds of ash has been studied. Many ash spheres were observed on the surface of coke matrix and its size was dependent on ash properties.

    La operación del horno alto con una tasa baja de coque, una cantidad elevada de hidrocarburos auxiliares y el empleo de coque calibrado, origina un cambio en las necesidades de calidad del coque. En particular, pueden influir en el comportamiento del coque los residuos inquemados en el raceway (cavidad enfrente a las toberas del horno de las sustancias que se inyectan (char y cenizas. El char es el residuo de carbón que se origina después que el carbón libera sus sustancias volátiles. Por tanto, se ha investigado la eficiencia de la combustión de varios residuos orgánicos con y sin inyección de carbón pulverizado (ICP y char, bajo las condiciones de simulación del raceway. La mezcla de varias sustancias mejora la eficiencia a la combustión. El estudio de la gasificación del coque por el dióxido de carbono en la

  16. Pore solution in alkali-activated slag cement pastes. Relation to the composition and structure of calcium silicate hydrate

    International Nuclear Information System (INIS)

    Puertas, F.; Fernandez-Jimenez, A.; Blanco-Varela, M.T.

    2004-01-01

    In this work, the relationship between the composition of pore solution in alkali-activated slag cement (AAS) pastes activated with different alkaline activator, and the composition and structure of the main reaction products, has been studied. Pore solution was extracted from hardened AAS pastes. The analysis of the liquids was performed through different techniques: Na, Mg and Al by atomic absorption (AA), Ca ions by ionic chromatography (IC) and Si by colorimetry; pH was also determined. The solid phases were analysed by XRD, FTIR, solid-state 29 Si and 27 Al NMR and BSE/EDX. The most significant changes in the ionic composition of the pore solution of the AAS pastes activated with waterglass take place between 3 and 24 h of reaction. These changes are due to the decrease of the Na content and mainly to the Si content. Results of 29 Si MAS NMR and FTIR confirm that the activation process takes place with more intensity after 3 h (although at this age, Q 2 units already exist). The pore solution of the AAS pastes activated with NaOH shows a different evolution to this of pastes activated with waterglass. The decrease of Na and Si contents progresses with time. The nature of the alkaline activator influences the structure and composition of the calcium silicate hydrate formed as a consequence of the alkaline activation of the slag. The characteristic of calcium silicate hydrate in AAS pastes activated with waterglass is characterised by a low structural order with a low Ca/Si ratio. Besides, in this paste, Q 3 units are detected. The calcium silicate hydrate formed in the pastes activated with NaOH has a higher structural order (higher crystallinity) and contains more Al in its structure and a higher Ca/Si ratio than those obtained with waterglass

  17. Assessment of Pb-slag, MSWI bottom ash and boiler and fly ash for using as a fine aggregate in cement mortar.

    Science.gov (United States)

    Saikia, Nabajyoti; Cornelis, Geert; Mertens, Gilles; Elsen, Jan; Van Balen, Koenraad; Van Gerven, Tom; Vandecasteele, Carlo

    2008-06-15

    Three types of wastes, metallurgical slag from Pb production (SLG), the sand-sized (0.1-2 mm) fraction of MSWI bottom ash from a grate furnace (SF), and boiler and fly ash from a fluidised bed incinerator (BFA), were characterized and used to replace the fine aggregate during preparation of cement mortar. The chemical and mineralogical behaviour of these wastes along with the reactivities of the wastes with lime and the hydration behaviour of ordinary Portland cement paste with and without these wastes added were evaluated by various chemical and instrumental techniques. The compressive strengths of the cement mortars containing waste as a partial substitution of fine aggregates were also assessed. Finally, leaching studies of the wastes and waste containing cement mortars were conducted. SLG addition does not show any adverse affect during the hydration of cement, or on the compressive strengths behaviours of mortars. Formation of expansive products like ettringite, aluminium hydroxide and H2 gas due to the reaction of some constituents of BFA and SF with alkali creates some cracks in the paste as well as in the cement mortars, which lower the compressive strength of the cement mortars. However, utilization of all materials in cement-based application significantly improves the leaching behaviour of the majority of the toxic elements compared to the waste as such.

  18. Compare pilot-scale and industry-scale models of pulverized coal combustion in an ironmaking blast furnace

    Science.gov (United States)

    Shen, Yansong; Yu, Aibing; Zulli, Paul

    2013-07-01

    In order to understand the complex phenomena of pulverized coal injection (PCI) process in blast furnace (BF), mathematical models have been developed at different scales: pilot-scale model of coal combustion and industry-scale model (in-furnace model) of coal/coke combustion in a real BF respectively. This paper compares these PCI models in aspects of model developments and model capability. The model development is discussed in terms of model formulation, their new features and geometry/regions considered. The model capability is then discussed in terms of main findings followed by the model evaluation on their advantages and limitations. It is indicated that these PCI models are all able to describe PCI operation qualitatively. The in-furnace model is more reliable for simulating in-furnace phenomena of PCI operation qualitatively and quantitatively. These models are useful for understanding the flow-thermo-chemical behaviors and then optimizing the PCI operation in practice.

  19. Injection of natural gas in the blast furnace tuyeres three of the Usiminas, Ipatinga Plant; Injecao de gas natural nas ventaneiras do alto-forno 3 da Usiminas, Usina de Ipatinga

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Murilo Alves Tito de; Rosa, Ericson Rimen Ribeiro; Oliveira, Claudiney Freitas de; Hostt, Helton [USIMINAS, Ipatinga, MG (Brazil). Gerencia Geral de Reducao

    2011-12-21

    The reduction in production costs is a major strategic objectives of Usiminas and the use of natural gas in the Blast Furnace 3 (BF 3) contribute to achieve this goal. The use of natural gas as fuel in the BF 3 to reduce the use of metallurgical coke (main fuel) and reduces production losses during periods of maintenance in the pulverized coal injection system and improving operational control of the Blast Furnace. The work presents the deployment of the natural gas injection and the performance obtained by the BF 3 from the start of injection, with a focus on reducing consumption of metallurgical coke and stable operation of blast furnace (author)

  20. Distinctive microstructural features of aged sodium silicate-activated slag concretes

    Energy Technology Data Exchange (ETDEWEB)

    San Nicolas, Rackel [Department of Chemical and Biomolecular Engineering, University of Melbourne, Victoria 3010 (Australia); Bernal, Susan A. [Department of Materials Science and Engineering, University of Sheffield, Sir Robert Hadfield Building, Mappin St, Sheffield S1 3JD (United Kingdom); School of Materials Engineering, Composite Materials Group, Universidad del Valle, Cali (Colombia); Mejía de Gutiérrez, Ruby [School of Materials Engineering, Composite Materials Group, Universidad del Valle, Cali (Colombia); Deventer, Jannie S.J. van [Department of Chemical and Biomolecular Engineering, University of Melbourne, Victoria 3010 (Australia); Zeobond Pty Ltd, P.O. Box 23450, Docklands, Victoria 8012 (Australia); Provis, John L., E-mail: j.provis@sheffield.ac.uk [Department of Materials Science and Engineering, University of Sheffield, Sir Robert Hadfield Building, Mappin St, Sheffield S1 3JD (United Kingdom)

    2014-11-15

    Electron microscopic characterisation of 7-year old alkali-activated blast-furnace slag concretes enabled the identification of distinct microstructural features, providing insight into the mechanisms by which these materials evolve over time. Backscattered electron images show the formation of Liesegang-type ring formations, suggesting that the reaction at advanced age is likely to follow an Oswald supersaturation–nucleation–depletion cycle. Segregation of Ca-rich veins, related to the formation of Ca(OH){sub 2}, is observed in microcracked regions due to the ongoing reaction between the pore solution and available calcium from remnant slag grains. A highly dense and uniform interfacial transition zone is identified between siliceous aggregate particles and the alkali activated slag binders, across the concretes assessed. Alkali-activated slag concretes retain a highly dense and stable microstructure at advanced ages, where any microcracks induced at early ages seem to be partially closing, and the remnant slag grains continue reacting.

  1. Modelling of chemical evolution of low pH cements at long term

    International Nuclear Information System (INIS)

    El Bitouri, Y.; Buffo-Lacarriere, L.; Sellier, A.; Bourbon, X.

    2015-01-01

    In the context of the underground radioactive waste repository, low-pH cements were developed to reduce interactions between concrete and clay barrier. These cements contain high proportions of mineral additions like silica fume, fly ash or blast furnace slag for example. The high ratio of cement replacement by pozzolanic additions allows to reduce the pH by a global reduction of Ca/Si ratio of the hydrates (according to the one observed on CEM I pastes). In order to predict the short term development of the hydration for each component of this cement, a multiphasic hydration model, previously developed, is used. The model predicts the evolution of hydration degree of each anhydrous phase and consequently the quantity of each hydrate in paste (CH, aluminates, CSH with different Ca/Si ratios). However, this model is not suitable to determine the long term mineralogical and chemical evolution of the material, due to the internal change induced by chemical imbalance between initial hydrates. In order to evaluate the chemical characteristics of low pH cement based materials, and thus assess its chemical stability in the context of radioactive waste storage, a complementary model of chemical evolution at long term is proposed. This original model is based on 'solid-solution' principles. It assumes that the microdiffusion of calcium plays a major role to explain how the different Ca/Si ratio of initial C-S-H tends together toward a medium stabilized value. The main mechanisms and full development of the model equations are presented first. Next, a comparison of the model with experimental data issue from EDS (Energy Dispersive X-ray Spectroscopy) analysis on low pH cement allows to test the model. (authors)

  2. Reducing CO2-Emission by using Eco-Cements

    Science.gov (United States)

    Voit, K.; Bergmeister, K.; Janotka, I.

    2012-04-01

    CO2 concentration in the air is rising constantly. Globally, cement companies are emitting nearly two billion tonnes/year of CO2 (or around 6 to 7 % of the planet's total CO2 emissions) by producing portland cement clinker. At this pace, by 2025 the cement industry will be emitting CO2 at a rate of 3.5 billion tones/year causing enormous environmental damage (Shi et al., 2011; Janotka et al., 2012). At the dawn of the industrial revolution in the mid-eighteenth century the concentration of CO2 was at a level of ca. 280 ppm. 200 years later at the time of World War II the CO2 level had risen to 310 ppm what results in a rate of increase of 0,15 ppm per year for that period (Shi et al., 2011). In November 2011 the CO2 concentration reached a value of 391 ppm (NOAA Earth System Research Laboratory, 2011), a rise of ca. 81 ppm in 66 years and an increased rate of around 1,2 ppm/year respectively. In the same period cement production in tons of cement has multiplied by a factor of ca. 62 (Kelly & Oss, US Geological Survey, 2010). Thus new CO2-saving eco-cement types are gaining in importance. In these cement types the energy-consuming portland cement clinker is partially replaced by latent hydraulic additives such as blast furnace slag, fly ash or zeolite. These hydraulic additives do not need to be fired in the rotary furnace. They ony need to be pulverized to the required grain size and added to the ground portland cement clinker. Hence energy is saved by skipping the engery-consuming firing process, in addition there is no CO2-degassing as there is in the case of lime burning. Therefore a research project between Austria and Slovakia, funded by the EU (Project ENVIZEO), was initiated in 2010. The main goal of this project is to develop new CEM V eco-types of cements and certificate them for common usage. CEM V is a portland clinker saving cement kind that allows the reduction of clinker to a proportion of 40-64% for CEM V/A and 20-39% for CEM V/B respectively by the

  3. Characterization of fly ash, slag and glass hull for the obtaining of vitreous materials

    Science.gov (United States)

    Ayala Valderrama, D. M.; Gómez Cuaspud, J. A.

    2017-12-01

    This article presents the structural and thermal characterization of fly ash, the waste from blast furnace slag and the glass hull, generated as common residues in industry, which cannot be recycled easily or destroyed in a simple and fast way. In the particular case of fly ash, at present are being used as a lightweight aggregate in the production of cement, concrete and additive in the production of glass and glass ceramics. As far as the slag and hull, are being used as additives for the asphalt and concretes, however its use still is restricted, reason why its use in alternative ways are necessary. Initially the chemical composition of residues was established, determining that the fly ashes contains SiO2, Al2O3 and Fe2O3 oxides; 90% of the total composition, was confirmed by X-ray diffraction analysis. As minor constituents, small percentages of Mg, P, S, K, Na and Ti were found. For the slag case, the phases of Fe3O4, Ca3Mg (SiO2)4 and Ca(MgAl)(Si,Al)2O6 were identified, observing the presence of amorphous phase higher than 94% of the total phase of the system. Meanwhile, the glass hull sample showed a higher percentage of 95% amorphicity, mainly identifying a weak signal associated with silicon oxide SiO2. The thermal analyses of the samples, exhibit a decrease in mass for samples between 25-1000°C was observed, which can be attributed to different physical-chemical events that occur in the materials. The heat flow for each sample is related with the removal of the water retained by the physisorption processes around 92-110°C in all cases. With this previous characterization of the precursors, a sample was composed using 70% fly ash, 10% slag and 20% of glass hull was composed and treated at 1200°C/1.5 hours, obtaining a dense black glassy material for potential applications in field of the glass ceramics.

  4. Perméabilité au gaz et aux ions chlore des mortiers à base de laitier de faible hydraulicité Gas and chloride ions permeability of mortar with low hydraulicity slag

    Directory of Open Access Journals (Sweden)

    Courard L.

    2012-09-01

    Full Text Available La durabilité des bétons au laitier de haut fourneau dépend fortement de l’activité hydraulique du laitier. Dans cette étude, un laitier algérien, caractérisé par une faible hydraulicité, est utilisé dans la fabrication de mortiers comme substituant du ciment à des taux de 0, 30 et 50%. En plus d’une caractérisation mécanique, l’effet du laitier sur la durabilité des mortiers est évalué par des essais de perméabilité à l’oxygène, de diffusion de chlorures en régime permanent ainsi que de conduction des ions chlore (essai accéléré ASTM. Les résultats montrent, malgré une faible réactivité du laitier, une amélioration de la perméabilité à l’oxygène à long terme (360 jours pour les mortiers au laitier, particulièrement pour un taux de 50%. La présence du laitier réduit la perméabilité aux ions chlore, d’une part, en augmentant le temps de passage des chlorures à travers le mortier et, d’autre part, en diminuant le taux de diffusion. Par ailleurs, une faible conduction des chlorures est observée pour les mortiers au laitier, montrant une similitude avec les résultats d’essai de diffusion en régime permanent. Durability of ground granulated blast furnace slag concrete depends largely on the hydraulic activity of the slag. In this study, a low activity Algerian slag is used as a substitution to cement in the manufacture of mortars at rates of 0, 30 and 50%. In addition to the mechanical characterization, the effect of slag on the durability of mortars is evaluated by oxygen permeability test, chlorides diffusion test in steady state and chlorides conduction test (ASTM accelerated test. Despite the low activity of slag, the results show improved oxygen permeability at long term (360 days for slag mortars, particularly for a 50% rate. The presence of slag reduces the chloride permeability by on one hand increasing the time of passage of the chlorides through mortar and, on the other hand, by

  5. The Balance of Titanium and Vanadium in the Blast Furnace with the Use of Sinter Containing a Titanium-Vanadium-Magnetite Concentrate

    Directory of Open Access Journals (Sweden)

    Budzik, R.

    2007-01-01

    Full Text Available The investigation concerned the use of sinter containing a titanium-vanadium-magnetite concentrate for the production of pig iron. Sinter containing 0,46 to 0,51 % TiO2 and 0,056 to 0,060 % vanadium was used for pig iron production in the blast furnace. Introducing 200 kg of this concentrate to the1 Mg sinter mix did not cause any deterioration of sinter quality.

  6. Sadhana | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    . Volume 42 Issue 7 July 2017 pp 1203-1213. Strength development characteristics of concrete produced with blended cement using ground granulated blast furnace slag (GGBS) under various curing conditions · SHAHAB SAMAD ...

  7. Thermostrengthening modes in getting heat-strengthened pellets in weak oxidizing atmosphere with residual carbon for blast furnace melting

    Directory of Open Access Journals (Sweden)

    Євген Валерійович Чупринов

    2016-11-01

    Full Text Available In the course of the laboratory tests, that are close to industrial modes of bowl pelletizers and roasting bowl operations, thermostrengthening modes of raw pellets have been worked out and selected, the main technological feature of the pellets being the presence of rolled up solid fuel. The results, obtained in the tests, showed that the selected modes make it possible to get heat-strengthened pellets with the maximum amount of residual carbon in the final product. The results, demonstrating the effect of the heating rate on the process parameters, in particular, on the content of residual carbon in the obtained heat-strengthened pellets are important. It has been shown that increasing the heating rate of raw pellets from 100 to 500°C/min, and cooling rate of the heat-strengthened pellets from 100 to 600°C/min with decreasing oxygen content in the heat-carrying agent for gas burning in the burners and cooling gas from 21% to 10,3-5,1% make it possible to increase the content of residual carbon in the heat-strengthened pellets from 0,8-1,9% to 3,5-3,7%. The obtained heat-strengthened pellets with the residual carbon not only satisfy all the requirements of the blast furnace melting, but also possess better metallurgical characteristics than oxidized heat-strengthened pellets

  8. Results of tuyere coke sampling with regard to application of appropriate coke strength after reaction (CSR for a blast furnace

    Directory of Open Access Journals (Sweden)

    Shiau J-S.

    2017-01-01

    Full Text Available Raising pulverized coal injection (PCI will decrease coke rate, but increase the residence time of coke and abrasion in the blast furnace (BF. Thus, insufficient coke strength will generate more coke fines in the lower BF and result in lower permeability and production of hot metal (HM. For understanding the behavior of coke at various HM productivities, a tuyere coke sampler was used to collect the coke samples for measuring the coke strength. Firstly, the difference of sampled coke under the conditions of various HM productivities was explored. Secondly, the BF operating conditions and causes of generating more coke fines was correlated by testing the coke reaction rate after reaction. Finally, according to the above analysis results, the relative regression equations had been obtained for sampling coke properties, BF operation conditions and BF permeability. Furthermore, the coke strength after reaction (CSR quantitative target and its online system at various blast conditions were set to provide some reference for coke and HM production.

  9. Rheological behavior and constitutive equations of heterogeneous titanium-bearing molten slag

    Science.gov (United States)

    Jiang, Tao; Liao, De-ming; Zhou, Mi; Zhang, Qiao-yi; Yue, Hong-rui; Yang, Song-tao; Duan, Pei-ning; Xue, Xiang-xin

    2015-08-01

    Experimental studies on the rheological properties of a CaO-SiO2-Al2O3-MgO-TiO2-(TiC) blast furnace (BF) slag system were conducted using a high-temperature rheometer to reveal the non-Newtonian behavior of heterogeneous titanium-bearing molten slag. By measuring the relationships among the viscosity, the shear stress and the shear rate of molten slags with different TiC contents at different temperatures, the rheological constitutive equations were established along with the rheological parameters; in addition, the non-Newtonian fluid types of the molten slags were determined. The results indicated that, with increasing TiC content, the viscosity of the molten slag tended to increase. If the TiC content was less than 2wt%, the molten slag exhibited the Newtonian fluid behavior when the temperature was higher than the critical viscosity temperature of the molten slag. In contrast, the molten slag exhibited the non-Newtonian pseudoplastic fluid characteristic and the shear thinning behavior when the temperature was less than the critical viscosity temperature. However, if the TiC content exceeded 4wt%, the molten slag produced the yield stress and exhibited the Bingham and plastic pseudoplastic fluid behaviors when the temperature was higher and lower than the critical viscosity temperature, respectively. When the TiC content increased further, the yield stress of the molten slag increased and the shear thinning phenomenon became more obvious.

  10. Elementary characterization of samples of Portland cement, natural gypsum and phosphogypsum mortars from Brazil

    International Nuclear Information System (INIS)

    Narloch, Danielle Cristine; Paschuk, Sergei Anatolyevich; Corrêa, Janine Nicolosi; Torres, Catarina Alzira Peddis; Mazer, Wellington; Macioski, Gustavo; Lara, Alessandro

    2017-01-01

    Portland cement, the basic ingredient of concrete and is manufactured by crushing, milling and proportioning limestone, sand, clay, iron ore and secondary materials such as shells, chalk or marl combined with shale slate or blast furnace slag, fly ash, gypsum, phosphogypsum, and some others. Evaluating the physical and mineralogical characteristics of the cement and its chemical composition is essential to establish the quality of the product. Therefore, the objective of this work was to characterize and quantify the most common chemical elements in the samples of Brazilian Portland cement, natural gypsum, and phosphogypsum mortars by means of X-ray dispersive energy spectroscopy (EDXRF), as well as to evaluate the strength of these mortars. For analysis of the compressive strength, initially prepared samples were submitted to a destructive mechanical test. Subsequently samples were milled and compacted to form thin tablets, which were submitted to the EDXRF analysis. The qualitative and quantitative analyzes showed that for phosphogypsum mortar the largest mass fractions were found of 49.8±2.5% (Si), 24.66±0.96% (S) and 22.10±0.42% (Ca). For gypsum mortar those values were found of 43.41±0.45% (Ca), 33.8 ± 0.8% (S) and 18.9±1.2% (Si), respectively; and for Portland cement mortar, the predominant elements in those samples have the mass fractions of 64.20±0.52% (Ca) and 27.3±1.5% (Si). The results showed that obtained values of mass fraction of the elements Si, S, K, Ca, Ti, Fe are in rather good agreement with quantities indicated for manufacture. Besides, gypsum and phosphogypsum presented almost the same composition and compressive strength. (author)

  11. Elementary characterization of samples of Portland cement, natural gypsum and phosphogypsum mortars from Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Narloch, Danielle Cristine; Paschuk, Sergei Anatolyevich; Corrêa, Janine Nicolosi; Torres, Catarina Alzira Peddis; Mazer, Wellington; Macioski, Gustavo [Universidade Tecnologica Federal do Parana (UTFPR), PR (Brazil); Lara, Alessandro [Universidade de Sao Paulo (USP), SP (Brazil). Departamento de Fisica; Casali, Juliana Machado, E-mail: janine_nicolosi@hotmail.com, E-mail: alellara@hotmail.com, E-mail: jucasali@gmail.com [Instituto Federal de Santa Catarina (IFSC), Florianópolis, SC (Brazil)

    2017-07-01

    Portland cement, the basic ingredient of concrete and is manufactured by crushing, milling and proportioning limestone, sand, clay, iron ore and secondary materials such as shells, chalk or marl combined with shale slate or blast furnace slag, fly ash, gypsum, phosphogypsum, and some others. Evaluating the physical and mineralogical characteristics of the cement and its chemical composition is essential to establish the quality of the product. Therefore, the objective of this work was to characterize and quantify the most common chemical elements in the samples of Brazilian Portland cement, natural gypsum, and phosphogypsum mortars by means of X-ray dispersive energy spectroscopy (EDXRF), as well as to evaluate the strength of these mortars. For analysis of the compressive strength, initially prepared samples were submitted to a destructive mechanical test. Subsequently samples were milled and compacted to form thin tablets, which were submitted to the EDXRF analysis. The qualitative and quantitative analyzes showed that for phosphogypsum mortar the largest mass fractions were found of 49.8±2.5% (Si), 24.66±0.96% (S) and 22.10±0.42% (Ca). For gypsum mortar those values were found of 43.41±0.45% (Ca), 33.8 ± 0.8% (S) and 18.9±1.2% (Si), respectively; and for Portland cement mortar, the predominant elements in those samples have the mass fractions of 64.20±0.52% (Ca) and 27.3±1.5% (Si). The results showed that obtained values of mass fraction of the elements Si, S, K, Ca, Ti, Fe are in rather good agreement with quantities indicated for manufacture. Besides, gypsum and phosphogypsum presented almost the same composition and compressive strength. (author)

  12. Products of steel slags an opportunity to save natural resources.

    Science.gov (United States)

    Motz, H; Geiseler, J

    2001-01-01

    In Germany, and in the most industrial countries, the use of blast furnace and steel slags as an aggregate for civil engineering, for metallurgical use and as fertiliser has a very long tradition. Since the introduction of the basic oxygen steel making furnace (BOF) process and the electric arc furnace (EAF) process the German steel industry started extensive research on the development of fields of application for BOF and EAF slags. These investigations have been mainly performed by Forschungsgemeinschaft Eisenhüttenschlacken e. V. (FEhS), the Research Association for blast furnace and steel slags. Today steel slags are well characterised and long-term experienced materials mainly used as aggregates for road construction (e.g. asphaltic or unbound layers), as armour-stones for hydraulic engineering constructions (e.g. stabilisation of shores), and as fertiliser for agriculture purposes. These multifarious fields of application could only be achieved because the steelworks influence the quality of slags by a careful selection of raw materials and a suitable process route. Furthermore, subsequent procedures like a treatment of the liquid slag, an appropriate heat treatment and a suitable processing have been developed to ensure that the quality of steel slags is always adequate for the end use. Depending on the respective field of application, the suitability of steel slags has to be proven by determining the technical properties, as well as the environmental compatibility. For this reason test methods have been developed to evaluate the technical properties especially the volume stability and the environmental behaviour. To evaluate the volume stability a suitable test (steam test) has been developed and the results from laboratory tests were compared with the behaviour of steel slags under practical conditions, e.g. in a road. To determine the environmental behaviour leaching tests have been developed. In the meanwhile most of these test methods are drafted or

  13. Use of a simplified generalized standard additions method for the analysis of cement, gypsum and basic slag by slurry nebulization ICP-OES.

    Science.gov (United States)

    Marjanovic, Ljiljana; McCrindle, Robert I; Botha, Barend M; Potgieter, Herman J

    2004-05-01

    The simplified generalized standard additions method (GSAM) was investigated as an alternative method for the ICP-OES analysis of solid materials, introduced into the plasma in the form of slurries. The method is an expansion of the conventional standard additions method. It is based on the principle of varying both the sample mass and the amount of standard solution added. The relationship between the sample mass, standard solution added and signal intensity is assumed to be linear. Concentration of the analyte can be found either geometrically from the slope of the two-dimensional response plane in a three-dimensional space or mathematically from the ratio of the parameters estimated by multiple linear regression. The analysis of a series of certified reference materials (CRMs) (cement CRM-BCS No 353, gypsum CRM-Gyp A and basic slag CRM No 382/I) introduced into the plasma in the form of slurry is described. The slurries contained glycerol and hydrochloric acid and were placed in an ultrasonic bath to ensure good dispersion. "Table curve 3D" software was used to fit the data. Results obtained showed that the method could be successfully applied to the analysis of cement, gypsum and slag samples, without the need to dissolve them. In this way, we could avoid the use of hazardous chemicals (concentrated acids), incomplete dissolution and loss of some volatiles. The application of the simplified GSAM for the analysis did not require a CRM with similar chemical and mineralogical properties for the calibration of the instrument.

  14. Compósitos de cimento - borracha de pneus: efeito da escória nas propriedades Tire rubber-cement composites: effect of slag on properties

    Directory of Open Access Journals (Sweden)

    N. Segre

    2006-12-01

    .Tire rubber-cement composites prepared with type I and three slag-modified cements were studied. Flexural strength, water sorption and resistance to acid attack of specimens were investigated. A decrease in modulus of rupture (MOR is observed for all specimens containing rubber, when compared with specimens without rubber (controls. The MOR increases with the increase of the hydraulic activity of the slag upon undistinguishable from specimens prepared with type I cement. This behavior is observed for all slag-cements pastes and for mortars control specimens. For mortar specimens with rubber the MOR is independent of the cement type used. A reduction in water sorption is observed for control and with-rubber mortar specimens prepared with all slag-cements, when compared to type I cement. For mortar specimens with rubber, the lower the basicity of the slag, the lesser the water sorption of the composites. These results denote lower porosity and consequently better rubber-matrix adhesion for these specimens. Also, a smaller rate of water sorption is observed for specimens with rubber, particularly for specimens prepared with the less basic slag cements, when comparing with the controls. Results of acid attack to the slag modified mortars indicate that specimen susceptibility is governed not only by microstructural aspects, like porosity and permeability, but also by chemical aspects as the difference in alkali content or the amount of unreacted slag in the specimens.

  15. A study of radioactivity level of the cements containing fly ash of Soma power plant

    International Nuclear Information System (INIS)

    Aslan, A.; Oezer, N.; Suener, U.

    2009-01-01

    Cement is a product that is formed by grinding gypsum with clinkers resulted by burning the mixture that is obtained after mixing and grinding mainly silicium, calcium, alumina and iron oxides containing raw materials in certain proportions, to sintered degrees. When combined with water it posses binding properties. For portland cements, % 3-6 proportion gypsum (CaSO 4 .2H 2 O) in weight are added to clinkers at the grinding step in order to adjust the hydration degrees. By this way it prevents tricalcium aluminate (3CaO.Al 2 O 3 ) from rapid hardening. If ground without gypsum addition, clinkers when combined with water, harden rapidly. Additives such as fly ash, blast furnace slag, natural slag and trash possessing puzzolanic properties are also added to portland cement clinkers. At power plants, during the burning process of coals, light elements such as hydrogen and carbon are converted to their gaseous forms, and remaining ashes than become rich with uranium content. Thus fly ashes contain radioactive elements such as U-238 (Uranium), Th-232 (Thorium) and K-40 (Potassium). U-238 found in fly ash is not an intensively radioactive element at the beginning. It disintegrates naturally by losing its and particles and is transformed to some radio nuclides. Ra-226 (Radium) is the most active element among these radio nuclides and it is transformed to radon gas (Rn-222) by losing new particle. The rare gas radon and radioactive radium extremely jeopardize human health. Fly ashes when used in cements, it can lead to increase in the radioactivity level which is of prime public concern. It is therefore important to determine the radioactivity level formed in the cements and compare with the standard values. In this study, photon emissions and mechanical strength tests of C type fly ash of Soma power plant and portland cements containing this fly ash under laboratory conditions were measured. In that manner it has been examined whether fly ashes may cause some significant

  16. Data-Driven Nonlinear Subspace Modeling for Prediction and Control of Molten Iron Quality Indices in Blast Furnace Ironmaking

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Ping; Song, Heda; Wang, Hong; Chai, Tianyou

    2017-09-01

    Blast furnace (BF) in ironmaking is a nonlinear dynamic process with complicated physical-chemical reactions, where multi-phase and multi-field coupling and large time delay occur during its operation. In BF operation, the molten iron temperature (MIT) as well as Si, P and S contents of molten iron are the most essential molten iron quality (MIQ) indices, whose measurement, modeling and control have always been important issues in metallurgic engineering and automation field. This paper develops a novel data-driven nonlinear state space modeling for the prediction and control of multivariate MIQ indices by integrating hybrid modeling and control techniques. First, to improve modeling efficiency, a data-driven hybrid method combining canonical correlation analysis and correlation analysis is proposed to identify the most influential controllable variables as the modeling inputs from multitudinous factors would affect the MIQ indices. Then, a Hammerstein model for the prediction of MIQ indices is established using the LS-SVM based nonlinear subspace identification method. Such a model is further simplified by using piecewise cubic Hermite interpolating polynomial method to fit the complex nonlinear kernel function. Compared to the original Hammerstein model, this simplified model can not only significantly reduce the computational complexity, but also has almost the same reliability and accuracy for a stable prediction of MIQ indices. Last, in order to verify the practicability of the developed model, it is applied in designing a genetic algorithm based nonlinear predictive controller for multivariate MIQ indices by directly taking the established model as a predictor. Industrial experiments show the advantages and effectiveness of the proposed approach.

  17. Iron making technology with fuels and other materials injection in blast furnace tuyeres. Part 1. Auxiliary fuels characteristics and its influence in the blast furnace process; Tecnologia de fabricacion de arrabio con la inyeccion de combustibles y otros materiales por toberas en el horno alto. I parte. Caracteristicas de los combustibles auxiliares y su influencia en el proceso del horno alto

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, L. [Union de Empresas de Recuperacion de Materias Primas. Ciudad de La Habana (Cuba); Cores, A.; Formoso, A. [Centro Nacional de Investigaciones Metalurgicas. Madrid (Spain); Babich, A.; Yaroshevskii, S. [Universidad Estatal Tecnologica de Donetsk. Ucrania (Ukraine)

    1998-06-01

    The injection of fuels by tuyeres in the blast furnace is a used practice in most furnaces with the principal aim to reduce the coke consumption by ton of pig iron produced. The nature of these fuels is very diverse and depends on the resources of each country and of the fuel price. At this moment the coal injection (pulverized and granular) is the most extended practice, and the number of furnaces with facilities for coal injection increases continuously. (Author) 14 refs.

  18. Considerations on the mechanical behavior and hydration process supersulphated cement (CSS) formulated with phosphogypsum; Consideracoes sobre a resistencia mecanica e o processo de hidratacao de cimentos supersulfatados (CSS) formulados com fosfogesso

    Energy Technology Data Exchange (ETDEWEB)

    Gracioli, Bruna; Varela, Maxwell Vinicius Favero; Beutler, Cheila Sirlene; Frare, Andreza; Luz, Caroline Angulski da; Pereira Filho, Jose Ilo, E-mail: maxwell@alunos.utfpr.edu.br, E-mail: cheila.beutler@gmail.com, E-mail: andreza2694@hotmail.com, E-mail: ilofilho@yahoo.com.br, E-mail: angulski@utfpr.edu.br [Universidade Tecnologica Federal do Parana (UTFPR), Pato Branco, PR (Brazil)

    2017-01-15

    Supersulfated Cements (SSC) are composed from blast furnace slag (90%), calcium sulfate (10-20%) and a small amount of alkali activator (up 5%). Gypsum is a conventional source of calcium sulfate, however, it can be replaced by phosphogypsum (PG), a byproduct from the production of phosphoric acid (H{sub 3}PO{sub 4}) with similar chemical and mineralogical composition of the gypsum. In Brazil, the production of this material is about 4.5 million tons per year. Because the SSC contains a higher calcium sulfate content (20%) in relation to Portland cement, a higher consumption of phosphogypsum is possible. The goal of this study was to investigate the phosphogypsum (PG) as an alternative source of calcium sulfate in order to obtain CSS. In addition to use of PG, the effects of both calcium sulfate and alkali activator content on the process of hydration were investigated. The results showed that SSC made with phosphogypsum met the minimum compressive strength required by the European standard for SSC (EN 15743/2010). Low heat of hydration rates mainly influenced by the low alkali activator content was observed. The excess of alkali activator (KOH) had different influences according to calcium sulfate content. In pastes made with low content (10%), 0.8% of KOH reduced the compressive strength, while in those with a high calcium sulfate content (20%) the high alkaline content resulted in the instability of ettringite. (author)

  19. Guidebook for Using the Tool BEST Cement: Benchmarking and Energy Savings Tool for the Cement Industry

    Energy Technology Data Exchange (ETDEWEB)

    Galitsky, Christina; Price, Lynn; Zhou, Nan; Fuqiu , Zhou; Huawen, Xiong; Xuemin, Zeng; Lan, Wang

    2008-07-30

    The Benchmarking and Energy Savings Tool (BEST) Cement is a process-based tool based on commercially available efficiency technologies used anywhere in the world applicable to the cement industry. This version has been designed for use in China. No actual cement facility with every single efficiency measure included in the benchmark will likely exist; however, the benchmark sets a reasonable standard by which to compare for plants striving to be the best. The energy consumption of the benchmark facility differs due to differences in processing at a given cement facility. The tool accounts for most of these variables and allows the user to adapt the model to operational variables specific for his/her cement facility. Figure 1 shows the boundaries included in a plant modeled by BEST Cement. In order to model the benchmark, i.e., the most energy efficient cement facility, so that it represents a facility similar to the user's cement facility, the user is first required to input production variables in the input sheet (see Section 6 for more information on how to input variables). These variables allow the tool to estimate a benchmark facility that is similar to the user's cement plant, giving a better picture of the potential for that particular facility, rather than benchmarking against a generic one. The input variables required include the following: (1) the amount of raw materials used in tonnes per year (limestone, gypsum, clay minerals, iron ore, blast furnace slag, fly ash, slag from other industries, natural pozzolans, limestone powder (used post-clinker stage), municipal wastes and others); the amount of raw materials that are preblended (prehomogenized and proportioned) and crushed (in tonnes per year); (2) the amount of additives that are dried and ground (in tonnes per year); (3) the production of clinker (in tonnes per year) from each kiln by kiln type; (4) the amount of raw materials, coal and clinker that is ground by mill type (in tonnes per

  20. Development of Composite Materials Under Ecological Aspects as Recycling Concept For Borosilicate Glass Containing Iron Slags

    International Nuclear Information System (INIS)

    Khalil, T.K.; Bossert, J.; Aly, H.F.; Bossert, J.

    1999-01-01

    Composite concept in materials science can be conveniently applied in the waste treatment technology to construct specific t ailor made c omposite materials, in which at least one of the phases is built by the waste material. In this work the applicability of this concept for the fixation and recycling of slags wastes is done, whereby different mixtures of blast furnace slags are mixed with two different borosilicate glasses, which serve as matrix material. Thermal behaviour of the produced compacts were studied. Both melting and powder technology are applied for the fabrication of dense products. The microstructure of sintered samples is investigated by electron microscopy. The mechanical properties such as hardness and fracture toughness are determined by a Vickers technique. An improvement of the fracture toughness of more than 50% over the value for the original glass VG 98 is achieved by slag addition

  1. Hot metal temperature prediction and simulation by fuzzy logic in a blast furnace; Prediccion y simulacion, mediante logica difusa, de la temperatura de salida del arrabio en un horno alto

    Energy Technology Data Exchange (ETDEWEB)

    Romero, M. A.; Jimenez, J.; Mochon, J.; Formoso, A.; Bueno, F. [Centro Nacional de Investigaciones Metalurgicas CENIM. Madrid (Spain); Menendez, J. L. [ACERALIA. Gijon Asturias (Spain)

    2000-07-01

    This work describes the development and further validation of a model devoted to blast furnace hot metal temperature forecast, based on Fuzzy logic principles. The model employs as input variables, the control variables of an actual blast furnace: Blast volume, moisture, coal injection, oxygen addition, etc. and it yields as a result the hot metal temperature with a forecast horizon of forty minutes. As far as the variables used to develop the model have been obtained from data supplied by an actual blast furnaces sensors, it is necessary to properly analyse and handle such data. Especial attention was paid to data temporal correlation, fitting by interpolation the different sampling rates. In the training stage of the model the ANFIS (Adaptive Neuro-Fuzzy Inference System) and the Subtractive Clustering algorithms have been used. (Author) 9 refs.

  2. Compound effect of CaCO{sub 3} and CaSO{sub 4}·2H{sub 2}O on the strength of steel slag: cement binding materials

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Liqian; Liu, Jiaxiang; Liu, Qian, E-mail: ljxpost@263.net [Beijing Key Laboratory of Electrochemical Process and Technology for Materials, The State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing (China)

    2016-03-15

    In this study, we replaced 30% of the cement with steel slag to prepare binding material; additionally, small amounts of CaCO{sub 3} and CaSO{sub 4}·2H{sub 2}O were added. This was done to study the compound effect of CaCO{sub 3} and CaSO{sub 4}·2H{sub 2}O on the strength of steel slag-cement binding materials. The hydration degree of the steel slag cementitious material was analyzed by XRD, TG and SEM. The results showed that the optimum proportions of CaCO{sub 3} and CaSO{sub 4}·2H{sub 2}O were 3% and 2%, respectively. Compared with the steel slag-cement binders without adding CaCO{sub 3} and CaSO{sub 4}·2H{sub 2}O, the compressive strength increased by 59.9% at 3 days and by 17.8% at 28 days. Acting as the nucleation matrix, CaCO{sub 3} could accelerate the hydration of C{sub 3}S. In addition, CaCO{sub 3} was involved in the hydration reaction, generating a new hydration product, which could stably exist in a slurry. Meanwhile, CaSO{sub 4}·2H{sub 2}O could increase the number of AFt. The compound effect of CaCO{sub 3} and CaSO{sub 4}·2H{sub 2}O enhanced the intensity of steel slag-cement binding materials and improved the whole hydration behavior. (author)

  3. Mechanical behaviour of steel fibre-reinforced alkali activated slag concrete

    Directory of Open Access Journals (Sweden)

    Puertas, F.

    2009-03-01

    Full Text Available This study addressed the mechanical behaviour of a steel fibre-reinforced alternative concrete made from waterglass (Na2SiO3.nH2O+NaOH- activated Colombian blast furnace slag. The mixes studied were prepared with 400 kg of cement and the fibres were added in proportions of 40 and 120 kg per cubic metre of concrete. 7-, 14- and 28-day concrete was tested for compressive, splitting tensile and flexural strength. The results obtained showed that adding steel fibre to alkaline concrete lowered early age compressive strength, and that this decline was more intense with rising volumes of steel. Flexural and splitting tensile strength grew, however, enhancing the toughness of the material. As a general rule, the mechanical strength of the plain and fibre-reinforced alkaline concretes studied was higher than exhibited by conventional ordinary Portland cement concrete prepared with similar proportions of cement and fibre.En este estudio se investigó el comportamiento mecánico de hormigones alternativos reforzados con fibras de acero, basados en una escoria siderúrgica colombiana activada alcalinamente con waterglass (Na2SiO3.nH2O+NaOH. Las mezclas en estudio fueron preparadas con 400 kg de cemento y las fibras fueron incorporadas en proporciones de 40 kg y 120 kg por metro cúbico de hormigón, respectivamente. Se evaluó el comportamiento mecánico de los hormigones frente a esfuerzos de compresión, tracción indirecta y flexión a edades de curado de 7, 14 y 28 días. Los resultados obtenidos indican que la incorporación de fibras de acero en los hormigones alcalinos reduce la resistencia a la compresión a edades tempranas siendo superior la pérdida de resistencia a mayores volúmenes de fibra incorporados, mientras que la resistencia a la flexión y tracción indirecta se incrementan significativamente, mejorando la tenacidad del material. En términos generales, es posible concluir que el comportamiento mecánico exhibido por los hormigones

  4. Effect of supplementary cementing materials on the concrete corrosion control

    Directory of Open Access Journals (Sweden)

    Mejía de Gutiérrez, R.

    2003-12-01

    Full Text Available Failure of concrete after a period of years, less than the life expected for which it was designed, may be caused by the environment to which it has been exposed or by a variety of internal causes. The incorporation of supplementary materials has at the Portland cement the purpose of improving the concrete microstructure and also of influence the resistance of concrete to environmental attacks. Different mineral by-products as ground granulated blast furnace slag (GGBS, silica fume (SF, metakaolin (MK, fly ash (FA and other products have been used as supplementary cementing materials. This paper is about the behavior of concrete in the presence of mineral additions. Compared to Portland cements, blended cements show lower heat of hydration, lower permeability, greater resistance to sulphates and sea water. These blended cements find the best application when requirements of durability are regarded as a priority specially on high performance concrete.

    La falla del concreto en un tiempo inferior a la vida útil para la cual se diseñó puede ser consecuencia del medio ambiente al cual ha estado expuesto o de algunas otras causas de tipo interno. La incorporación de materiales suplementarios al cemento Portland tiene el propósito de mejorar la microestructura del concreto y también de contribuir a la resistencia del concreto a los ataques del medio ambiente. Diferentes minerales y subproductos tales como escorias granuladas de alto horno, humo de sílice, metacaolín, ceniza volante y otros productos han sido usados como materiales suplementarios cementantes. Este documento presenta el comportamiento del hormigón en presencia de diferentes adiciones. Los cementos adicionados, comparados con los cementos Portland muestran bajos calores de hidratación, baja permeabilidad, mayor resistencia a sulfatos y a agua de mar. Estos cementos adicionados encuentran un campo de aplicación importante cuando los requerimientos de durabilidad son

  5. Use of cemented paste backfill in arsenic-rich tailings

    Science.gov (United States)

    Hamberg, Roger; Maurice, Christian; Alakangas, Lena

    2015-04-01

    Gold is extracted by cyanide leaching from inclusions in arsenopyrite from a mine in the north of Sweden. The major ore mineral assemblage consists of pyrrhotite and arsenopyrite-loellingite. Effluents from the gold extraction were treated with Fe2(SO4)3, with the aim to form stable As-bearing Fe-precipitates (FEP). The use of the method called cemented paste backfill (CPB) is sometimes suggested for the management of tailings. In CPB, tailings are commonly mixed with low proportions (3 - 7 %) of cement and backfilled into underground excavated area. To reduce costs, amendments such as granulated blast furnace slag (GBFS), biofuel fly ash (BFA) and cement kiln dust (CKD) are used for partial replacement of cement in CPB due to their pozzolanic and alkaline properties. The objective for this study was to evaluate the leaching behaviour of As in CPB-mixtures with low proportions (1 - 3 %) of BFA and ordinary cement and unmodified tailings. The selection of CPB-recipies was made based on technical and economical criterias to adress the demands deriving from the mining operations. Speciation of the As in ore and tailings samples revealed that mining processes have dissolved the majority of the arsenopyrite in the ore, causing secondary As phases to co-precipitate with newly formed FEP:s. Tank leaching tests (TLT) and weathering cells (WCT) were used to compare leaching behaviour in a monolithic mass contra a crushed material. Quantification of the presumed benefit of CPB was made by calculation of the cumulative leaching of As. Results from the leaching tests (TLT and WCT) showed that the inclusion of As-rich tailings into a cementitious matrix increased leaching of As. This behaviour could partially be explained by an increase of pH. The addition of alkaline binder materials to tailings increased As leaching due to the relocation of desorbed As from FEPs into less acid-tolerant species such as Ca-arsenates and cementitious As-phases. Unmodified tailings generated an

  6. Properties of ambient cured blended alkali activated cement concrete

    Science.gov (United States)

    Talha Junaid, M.

    2017-11-01

    This paper presents results of the development and strength properties of ambient-cured alkali activated geopolymer concrete (GPC). The study looks at the strength properties, such as compressive strength, splitting tensile strength, and elastic modulus of such concretes and its dependency on various parameters. The parameters studied in this work are the type and proportions of pre-cursor materials, type of activator and their respective ratios and the curing time. Two types of pre-cursor material; low calcium fly ash (FA) and ground granulated blast furnace slag (GGBFS) were activated using different proportions of sodium silicate and sodium hydroxide solutions. The results indicate that ambient cured geopolymer concrete can be manufactured to match strength properties of ordinary Portland cement concrete (OPC). The strength properties of GPC are dependent on the type and ratio of activator and the proportion of GGBFS used. Increasing the percentage of GGBFS increased the compressive and tensile strengths, while reducing the setting time of the mix. The effect of GGBFS on strength was more pronounced in mixes that contained sodium silicate as activator solution. Unlike OPC, ambient-cured GPC containing sodium silicate gain most of their strength in the first 7 days and there is no change in strength thereafter. However, GPC mixes not containing sodium silicate only achieve a fraction of their strength at 7 days and extended curing is required for such concretes to gain full strength. The results also indicate that the elastic modulus values of GPC mixes without sodium silicate are comparable to OPC while mixes with sodium silicate have elastic modulus values much lower than ordinary concrete.

  7. Nickel speciation in cement-stabilized/solidified metal treatment filtercakes

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Amitava, E-mail: reroy@lsu.edu [J. Bennett Johnston, Sr., Center for Advanced Microstructures and Devices, Louisiana State University, Baton Rouge, LA 70806, USA (United States); Stegemann, Julia A., E-mail: j.stegemann@ucl.ac.uk [Centre for Resource Efficiency & the Environment, Department of Civil, Environmental & Geomatic Engineering, University College London, Chadwick Building, Gower Street, London WC1E 6BT, UK (United Kingdom)

    2017-01-05

    Highlights: • XAS shows the same Ni speciation in untreated and stabilized/solidified filtercake. • Ni solubility is the same for untreated and stabilized/solidified filtercake. • Leaching is controlled by pH and physical encapsulation for all binders. - Abstract: Cement-based stabilization/solidification (S/S) is used to decrease environmental leaching of contaminants from industrial wastes. In this study, two industrial metal treatment filtercakes were characterized by X-ray diffractometry (XRD), thermogravimetric and differential thermogravimetric analysis (TG/DTG) and Fourier transform infrared (FTIR); speciation of nickel was examined by X-ray absorption (XAS) spectroscopy. Although the degree of carbonation and crystallinity of the two untreated filtercakes differed, α-nickel hydroxide was identified as the primary nickel-containing phase by XRD and nickel K edge XAS. XAS showed that the speciation of nickel in the filtercake was unaltered by treatment with any of five different S/S binder systems. Nickel leaching from the untreated filtercakes and all their stabilized/solidified products, as a function of pH in the acid neutralization capacity test, was essentially complete below pH ∼5, but was 3–4 orders of magnitude lower at pH 8–12. S/S does not respeciate nickel from metal treatment filtercakes and any reduction of nickel leaching by S/S is attributable to pH control and physical mechanisms only. pH-dependent leaching of Cr, Cu and Ni is similar for the wastes and s/s products, except that availability of Cr, Cu and Zn at decreased pH is reduced in matrices containing ground granulated blast furnace slag.

  8. Recycling of Sustainable Co-Firing Fly Ashes as an Alkali Activator for GGBS in Blended Cements

    Directory of Open Access Journals (Sweden)

    Yann-Hwang Wu

    2015-02-01

    Full Text Available This study investigates the feasibility of co-firing fly ashes from different boilers, circulating fluidized beds (CFB or stokers as a sustainable material in alkali activators for ground granulated blast-furnace slag (GGBS. The mixture ratio of GGBS and co-firing fly ashes is 1:1 by weight. The results indicate that only CF fly ash of CFB boilers can effectively stimulate the potential characteristics of GGBS and provide strength as an alkali activator. CF fly ash consists of CaO3 (48.5%, SiO2 (21.1%, Al2O3 (13.8%, SO3 (10.06%, Fe2O3 (2.25% and others (4.29%. SA fly ash consists of Al2O3 (19.7%, SiO2 (36.3%, Fe2O3 (28.4% and others (15.6%. SB fly ash consists of Al2O3 (15%, SiO2 (25.4%, Zn (20.6%, SO3 (10.9%, Fe2O3 (8.78% and others (19.32%. The mixtures of SA fly ash and SB fly ash with GGBS, respectively, were damaged in the compressive strength test during seven days of curing. However, the built up strength of the CF fly ash and GGBS mixture can only be maintained for 7–14 days, and the compressive strength achieves 70% of that of a controlled group (cement in hardening cement paste. The strength of blended CF fly ash and GGBS started to decrease after 28 days, and the phenomenon of ettrigite was investigated due to the high levels of sulfur content. The CaO content in sustainable co-firing fly ashes must be higher than a certain percentage in reacting GGBS to ensure the strength of blended cements.

  9. Recycling of Sustainable Co-Firing Fly Ashes as an Alkali Activator for GGBS in Blended Cements.

    Science.gov (United States)

    Wu, Yann-Hwang; Huang, Ran; Tsai, Chia-Jung; Lin, Wei-Ting

    2015-02-16

    This study investigates the feasibility of co-firing fly ashes from different boilers, circulating fluidized beds (CFB) or stokers as a sustainable material in alkali activators for ground granulated blast-furnace slag (GGBS). The mixture ratio of GGBS and co-firing fly ashes is 1:1 by weight. The results indicate that only CF fly ash of CFB boilers can effectively stimulate the potential characteristics of GGBS and provide strength as an alkali activator. CF fly ash consists of CaO₃ (48.5%), SiO₂ (21.1%), Al₂O₃ (13.8%), SO₃ (10.06%), Fe₂O₃ (2.25%) and others (4.29%). SA fly ash consists of Al₂O₃ (19.7%), SiO₂ (36.3%), Fe2O3 (28.4%) and others (15.6%). SB fly ash consists of Al₂O₃ (15%), SiO₂ (25.4%), Zn (20.6%), SO₃ (10.9%), Fe₂O₃ (8.78%) and others (19.32%). The mixtures of SA fly ash and SB fly ash with GGBS, respectively, were damaged in the compressive strength test during seven days of curing. However, the built up strength of the CF fly ash and GGBS mixture can only be maintained for 7-14 days, and the compressive strength achieves 70% of that of a controlled group (cement in hardening cement paste). The strength of blended CF fly ash and GGBS started to decrease after 28 days, and the phenomenon of ettrigite was investigated due to the high levels of sulfur content. The CaO content in sustainable co-firing fly ashes must be higher than a certain percentage in reacting GGBS to ensure the strength of blended cements.

  10. Recycling of Sustainable Co-Firing Fly Ashes as an Alkali Activator for GGBS in Blended Cements

    Science.gov (United States)

    Wu, Yann-Hwang; Huang, Ran; Tsai, Chia-Jung; Lin, Wei-Ting

    2015-01-01

    This study investigates the feasibility of co-firing fly ashes from different boilers, circulating fluidized beds (CFB) or stokers as a sustainable material in alkali activators for ground granulated blast-furnace slag (GGBS). The mixture ratio of GGBS and co-firing fly ashes is 1:1 by weight. The results indicate that only CF fly ash of CFB boilers can effectively stimulate the potential characteristics of GGBS and provide strength as an alkali activator. CF fly ash consists of CaO3 (48.5%), SiO2 (21.1%), Al2O3 (13.8%), SO3 (10.06%), Fe2O3 (2.25%) and others (4.29%). SA fly ash consists of Al2O3 (19.7%), SiO2 (36.3%), Fe2O3 (28.4%) and others (15.6%). SB fly ash consists of Al2O3 (15%), SiO2 (25.4%), Zn (20.6%), SO3 (10.9%), Fe2O3 (8.78%) and others (19.32%). The mixtures of SA fly ash and SB fly ash with GGBS, respectively, were damaged in the compressive strength test during seven days of curing. However, the built up strength of the CF fly ash and GGBS mixture can only be maintained for 7–14 days, and the compressive strength achieves 70% of that of a controlled group (cement in hardening cement paste). The strength of blended CF fly ash and GGBS started to decrease after 28 days, and the phenomenon of ettrigite was investigated due to the high levels of sulfur content. The CaO content in sustainable co-firing fly ashes must be higher than a certain percentage in reacting GGBS to ensure the strength of blended cements. PMID:28787970

  11. Characterization of Iron and Steel Industry Slags to be Recycled under Ecological Aspects as a Recycling Concept for Waste Treatment

    International Nuclear Information System (INIS)

    Khalil, T.K.; Aly, H.F.; Bossert, J.

    1999-01-01

    The recycling and final disposal of different types of industrial waste play an important role in decreasing environmental pollution all over the world. Three different solid waste slags from steel industries situated in the Helwan area (Cairo-Egypt), namely blast furnace slags, oxygen converter slags arc furnace slags were studied. The morphology of the collected slag powders was examined using scanning electron microscopy (SEM). Surface characteristics of the slag powders were measured through nitrogen gas adsorption and application of the BET equation at 77 K. The thermal behaviour of the slag powders was studied with the help of differential thermal analysis (DTA) and thermogravimetry(TG)> Due to the presence of some changes in the DTA base lines, possibly as a result of phase transformations, X-ray diffraction was applied to identify these phases. The sintering behaviour of the compact slag powders after isostatic pressing was evaluated using dilatometry. The sintering and melting temperature of the studied samples were determined using heating microscopy. The effect of changing sintering temperature and of applying different isostatic pressures on the density and porosity of the slag powder compacts was investigated

  12. Energy saving in the pig iron production in the blast furnace no. 5; Ahorro de energia en la produccion de arrabio en el alto horno No. 5

    Energy Technology Data Exchange (ETDEWEB)

    Gil Diaz, Ricardo A.; J Quiroz, Francisco; Rodriguez, Rita Patricia; Banuelos Garza, Yolanda [Altos Hornos de Mexico, S. A., Coahuila (Mexico)

    1993-12-31

    Altos Hornos de Mexico (AHMSA) is an iron and steel industry integrated to Grupo Acereros del Norte in Monclova, in the Coahuila state. With an a installed capacity of 3.1 millions of tons per annum o liquid steel. In its installations, AHMSA has the highest capacity blast furnace installed in Mexico, blast furnace No. 5, that has a useful volume of 2,163 cubic meters, designed to produce 4,800 tons of pig iron per day. The basic goal to achieve in the operations involved in the production of steel through the pig iron production in the blast furnace, is the hot metal production at the lowest attainable cost within the quality requirements specified by the steel makers. The most important criterion for the recognition of the attained success is the fuel consumption per ton of pig iron produced, with coke as the main fuel fed to the blast furnace and therefore of the greatest impact on the final product cost. AHMSA contemplated within its strategic plan, the reduction in the production of its coking plants derived from the natural aging of its furnaces, consequently it is pending the shortage of coke for productions higher than 2.6 MMT of liquid iron. In response to this, and faced to the true need of diminishing the production costs in the process of making pig iron, new practices have been implemented in the use of complementary fuels to partially substitute the metallurgical coke as an energy source for the blast furnace process. The use of natural gas, fuel oil and the gradual increase of the temperature of hot blow, have strongly impacted the metallurgical coke consumption, lowering it considerably and diminishing the costs per ton of pig iron in blast furnace No. 5. Another important issue, is the utilization of coke fines resulting form the sieving of the same, directly fed to the furnace load. This practice reduced the coke consumption, and most of all, the output of our coking plants was increased on being utilized at the maximum coke production

  13. PRODUCTION OF PAVING BLOCK AND KERB INCORPORATING BLASTFURNACE SLAG

    Directory of Open Access Journals (Sweden)

    İsa YÜKSEL

    2007-02-01

    Full Text Available This paper presents results of an experimental study about partial substitution of granulated blast-furnace slag (GBFS as fine aggregate in production of concrete paving blocks and kerbs. GBFS is replaced sand for different GBFS/sand ratios in concrete during production of kerb and paving block specimens. Some tests orienting towards strength and durability were applied on these specimens including control specimens that are produced with normal concrete. Then, the results of tested properties of GBFS-replaced specimens and control specimens were compared. GBFS decreases the compressive strength of paving blocks and kerbs according to the results. However, some durability properties which are more important than strength for these elements are improved with GBFS replacement. The most improved property was abrasion resistance. It is concluded that it is feasible to use GBFS in paving block and kerb production with an optimum replacement ratio for these specimens.

  14. Study on cementitious properties of steel slag

    Directory of Open Access Journals (Sweden)

    Zhu G.

    2013-01-01

    Full Text Available The converter steel slag chemical and mineral components in China’s main steel plants have been analysed in the present paper. The electronic microscope, energy spectrum analysis, X-ray diffraction analysis confirmed the main mineral compositions in the converter slag. Converter slag of different components were grounded to obtain a powder with specific surface area over 400m2/kg, making them to take place some part of the cement in the concrete as the admixture and carry out the standard tests. The results indicate that the converter slag can be used as cementitious materials for construction. Furthermore, physical mechanic and durability tests on the concrete that certain amount of cement be substituted by converter steel slag powder from different steel plants are carried out, the results show that the concrete with partial substitution of steel slag powder has the advantages of higher later period strength, better frost resistance, good wear resistance and lower hydration heat, etc. This study can be used as the technical basis for “Steel Slag Powder Used For Cement And Concrete”, “Steel Slag Portland Cement”, “Low Heat Portland Steel Slag Cement”, “Steel Slag Road Cement” in China, as well as a driving force to the works of steel slag utilization with high-value addition, circular economy, energy conservation and discharge reduction in the iron and steel industry.

  15. Phase equilibria between iron and slag in carbon monoxide/carbon dioxide/water atmospheres relevant to a novel flash ironmaking technology

    Science.gov (United States)

    Mohassab Ahmed, Mohassab Yousef

    In an effort to develop a novel flash ironmaking process, to be called the Sohn process in this dissertation, with the potential of steelmaking in a single continuous process, the phase equilibria involved and the chemistry of selected slag systems were investigated. The Sohn process is an ecofriendly flash ironmaking process for producing iron from iron oxide concentrates in a flash reactor using fuels and reductants that help reduce energy consumption and minimize greenhouse gas emissions. Amongst the proposed reductants and fuels are H2, natural gas, and coal gas. The molten bath (iron-slag bath) is expected to equilibrate with gas atmospheres of mainly H2/H 2O, CO/CO2/H2/H2O, and CO/CO2 corresponding to H2, natural gas/coal gas (NG/CG), and coke/coal (blast furnace, BF), respectively. The latter was investigated to allow comparison with the blast-furnace conditions. The slag composition was selected to resemble that of the blast furnace, which consisted of the CaO-MgO-SiO2-Al 2O2-FeO-MnO-P2O5 system with CaO/SiO 2 in the range 0.8 to 1.4. The temperature range was 1550 to 1650°C encompassing a wide range of expected ironmaking temperatures for the Sohn process. The oxygen partial pressure was maintained in the reducing range 10-10 to 10-9 atm in the three gas atmospheres. It was found that H2O dramatically affects the chemistry of the slag and strongly affects the phase equilibria in the slag as well as the equilibrium distribution of elements between slag and molten metal. It was found that the slags under H2O-containing (H2 and NG/CG) atmospheres had a moderately higher degree of polymerization as compared to that under the blast furnace conditions. H2O in the gas atmosphere also increased the activity coefficient of FeO in the slag and accordingly lowered the FeO content. The FeO content in the slag of H 2 (FeO wt% = 10) and NG/CG (11) was significantly less than under the BF (16) conditions. On the other hand, the average MgO solubility (22 wt%) under the

  16. The Influence of Allocation on the Carbon Footprint of Electricity Production from Waste Gas, a Case Study for Blast Furnace Gas

    Directory of Open Access Journals (Sweden)

    Joeri Van Mierlo

    2013-03-01

    Full Text Available Producing electricity from waste gas is an after treatment for waste gas while recovering the energy content. This paper addresses the methodology to calculate the effect that waste gas energy recovery has on lowering the impact of climate change. Greenhouse gases are emitted while burning the waste gas. However, a thorough study should include the production of the feedstock as well as the production of the infrastructure. A framework is developed to calculate the environmental impact of electricity production from waste gas with a life cycle approach. The present paper has a twofold purpose: to assess the climate change impact of generating electricity with blast furnace gas (BFG as a waste gas from the steel industry; and to establish a sensitivity assessment of the environmental implications of different allocation rules.

  17. Deicer scaling resistance of concrete mixtures containing slag cement. Phase 2 : evaluation of different laboratory scaling test methods.

    Science.gov (United States)

    2012-07-01

    With the use of supplementary cementing materials (SCMs) in concrete mixtures, salt scaling tests such as ASTM C672 have been found to be overly aggressive and do correlate well with field scaling performance. The reasons for this are thought to be b...

  18. Utilization of industrial waste products as pozzolanic material in cemented paste backfill of high sulphide mill tailings.

    Science.gov (United States)

    Ercikdi, Bayram; Cihangir, Ferdi; Kesimal, Ayhan; Deveci, Haci; Alp, Ibrahim

    2009-09-15

    In this study, the potential use of the industrial waste products including waste glass (WG), fly ash (FA), granulated blast furnace slag (GBFS) and silica fume (SF) as pozzolanic additive for the partial replacement of ordinary Portland cement (OPC) in cemented paste backfill (CPB) of sulphide-rich mill tailings was investigated. The influence of these industrial waste products on the short- and long-term mechanical performance of CPB was demonstrated. The rate of development of strength of CPB samples tended to slow down when the pozzolanic wastes were incorporated or increased in dosage in the binder phase. Severe losses (by 26%) in the strength of CPB samples produced from exclusively OPC occurred after an initial curing period of 56 days. The addition of WG (10-30 wt%) as a partial replacement of OPC was observed to aggravate further the strength losses of CPB samples. GBFS, FA and SF appeared to improve the long-term performance of CPB samples; albeit, only GBFS and SF could be incorporated into the binder phase only at certain levels i.e. up to 20 wt% GBFS and 15wt% SF in order to maintain a threshold strength level of 0.7MPa over 360 days. SEM studies have provided further insight into the microstucture of CPB and confirmed the formation of deleterious gypsum as the expansive phase. These findings have demonstrated that the industrial waste products including GBFS and SF can be suitably used as mineral additives to improve the long-term mechanical performance of CPB produced from sulphide-rich tailings as well as to reduce the binder costs in a CPB plant.

  19. Concretes with ternary composite cements. Part III: multicriteria optimization

    Directory of Open Access Journals (Sweden)

    Irassar, E. F.

    2007-06-01

    Full Text Available Optimization methods are tools of vital importance in composite material design, where large numbers of components and design criteria must be taken into account. The formulation of today’s separately milled custommade cements is a clear example of just such a case, for the components must be proportioned to yield mortars and concretes with the proper balance of durability, strength, financial and environmental features. Multicriteria optimization has been used to develop many materials, although its application in cement formulation has yet to be explored. The present paper discusses the use of an objective function to jointly optimize sorptivity and compressive strength in limestone- (up to 20% and/or granulated blast furnace slag- (up to 20% additioned Portland cement concrete.Los métodos de optimización constituyen una herramienta de vital importancia en el diseño de materiales compuestos, donde la cantidad de componentes de la mezcla y los criterios de diseño que deben tenerse en cuenta en el proceso de fabricación son numerosos. En la actualidad, la formulación de un cemento a medida (tailor made a partir del proceso de molienda separada es un claro ejemplo de ello, pues las proporciones relativas de las componentes de la mezcla deben permitir luego obtener morteros y hormigones con el equilibrio justo entre los requerimientos durables, mecánicos, económicos y ecológicos que se soliciten. La optimización por multicriterios ha sido empleada en el desarrollo de diversos materiales, sin embargo, su aplicación en la formulación del cemento no ha sido aún explorada. En este trabajo se presenta la optimización conjunta de la capacidad de absorción y la resistencia a compresión de hormigones elaborados con cemento Portland con caliza (hasta un 20% y/o escoria granulada de alto horno (hasta un 20% utilizando la función objetivo.

  20. Properties of slag concrete for low-level waste containment

    International Nuclear Information System (INIS)

    Langton, C.A.; Wong, P.B.

    1991-01-01

    Ground granulated blast furnace slag was incorporated in the concrete mix used for construction of low-level radioactive waste disposal vaults. The vaults were constructed as six 100 x 100 x 25 ft cells with each cell sharing internal walls with the two adjacent cells. The vaults were designed to contain a low-level radioactive wasteform called saltstone and to isolate the saltstone from the environment until the landfill is closed. Closure involves backfilling with native soil, installation of clay cap, and run-off control. The design criteria for the slag-substituted concrete included compressive strength, 4000 psi after 28 days; slump, 6 inch; permeability, less than 10 -7 cm/sec; and effective nitrate, chromium and technetium diffusivities of 10 -8 , 10 -12 and 10 -12 cm 2 /sec, respectively. The reducing capacity of the slag resulted in chemically reducing Cr +6 to Cr +3 and Tc +7 to Tc +4 and subsequent precipitation of the respective hydroxides in the alkaline pore solution. Consequently, the concrete vault enhances containment of otherwise mobile waste ions and contributes to the overall protection of the groundwater at the disposal site

  1. Investigation of concrete containing slag : Hampton River Bridge.

    Science.gov (United States)

    1986-01-01

    The study evaluated the properties of concretes containing slag in a 50% replacement of the portland cement to assess their suitability as an alternative to the portland cement concretes normally used in the construction of bridge substructures. For ...

  2. Slag viscosity prediction and characterisation Al{sub 2}O{sub 3}-CaO- 'FeO'-SiO{sub 2} and Al{sub 2}O{sub 3}-CaO-'FeO'-MgO-SiO{sub 2} systems

    Energy Technology Data Exchange (ETDEWEB)

    A. Kondratiev; E. Jak; P. Hayes

    2006-02-15

    An integrated research program is being conducted to provide the necessary technical information required to understand the development status of, and reduce the risks associated with, the implementation of advanced, high-efficiency power generation technologies based on coal gasification systems. The melting and flow behaviour of the mineral matter (slag) present in the entrained flow gasifier and iron blast furnace is regarded as a key issue in process design, operation and in coal selection. A comprehensive slag viscosity model is required to accurately predict coal slagging behaviour in the gasifier. A number of the slag viscosity models have been developed over past 20 years. The major constraint of these models is their validity over relatively limited compositional range that does not cover all possible compositions of slags originating from different coals.

  3. Use of plastics in blast furnace processes: A contribution to ecologically and economically acceptable recycling of plastic waste; Kunststoffverwertung im Hochofen - ein Beitrag zum oekologischen und oekonomischen Recycling von Altkunststoffen

    Energy Technology Data Exchange (ETDEWEB)

    Janz, J. [Stahlwerke Bremen GmbH (Germany)

    1996-12-31

    The use of plastics in blast furnace processes has a number of advantages. For one thing, existing facilities can be used with only slight reconstruction measures. Next, the blast furnace process does not necessarily require plastics and therefore is independent of the available plastics volume. Further, it has a high utilisation potential. For example, the Bremen blast furnace No. II has only 8 nozzles out of 32 which are suited for plastics, but it can utilize 70,000 t/a, which is more than 13 percent of the total plastics volume collected by DSD. Indepenent eco-balances have shown that there is no better technology on the market at the moment. (orig) [Deutsch] Mit der Kunststoffverwertung im Hochofen steht ein Verfahren zur Verfuegung, das sich gleich in mehrfacher Hinsicht vor der Konkurrenz auszeichnet. Im Gegensatz zu anderen Verwertungen wird eine bereits vorhandene Anlage genutzt, an der lediglich zusatzeinrichtungen benoetigt werden. Gleichzeitig wird abfallpolitische Flexibilitaet dadurch erreicht, dass der Hochofen nicht auf das Reduktionsmittel Kunststoff angewiesen ist. Von wesentlicher Bedeutung ist auch die hohe Verwertungskapazitaet eines Hochofens. Unabhaengige Oekobilanzen und eigene Messungen haben zweifelsfrei gezeigt, dass ein besseres Verfahren zur Zeit nicht auf dem Markt ist. (orig)

  4. NEW TECHNOLOGY OF ASH AND SLAG CONCRETES

    Directory of Open Access Journals (Sweden)

    PAVLENKO T. M.

    2017-03-01

    Full Text Available Summary. Purpose. Development of scientific-technical bases of manufacture and application of concrete on the basis of ash and slag mixes of thermal power plants. Methods. It is proposed a new technology of preparation of ash and slag concrete mixes. First the ash and slag mix is dispersed through the sieve with meshes 5 mm in a fine-grained fraction and slag. Then, in accordance with the composition of the concrete, obtained fine-grained fraction, slag, cement and tempering water are separately dosed into the mixer. Results. It is proven the high efficiency of the proposed technology of manufacture of ash and slag concretes. It is established that this technological solution allows to increase the strength of concrete by 20...30%, and in the preparation of full-strength concrete to reduce the cement consumption by 15...20%. Scientific novelty. It is developed the new technology of ash and slag mixes application. The concrete mix on the basis of ash and slag mix has an optimal particle size distribution, which ensures the best compaction and, accordingly, the greatest strength of ash and slag concrete with the given cement consumption. Practical significance. The research results promote the mass application of ash and slag mixes of thermal power plants in construction, obtaining of products from the proposed concretes of low cost with high physical-mechanical properties. Conclusion. It is proven the high efficiency of the proposed technology of production of ash and slag concretes. It is established that this technological solution allows increasing concrete strength, and obtaining full-strength concrete to reduce cement consumption. The extensive application of such concrete in construction makes it possible to solve the problem of aggregates for concrete, promotes recycling of TPP waste and consequently the protection of the environment.

  5. Suitability of Electric Arc Furnace (Eaf) Slag as Partial Replacement ...

    African Journals Online (AJOL)

    The use of Electric Arc Furnace (EAF) Slag which is a by-product solid waste in Steel Production was investigated for use as a partial replacement for cement in sandcrete blocks. The tests carried out on cement and finely ground slag to determine their compositions and physico-chemical properties as well as the evaluation ...

  6. Characterisation of chloride transport and reinforcement corrosion in concrete under cyclic wetting and drying by electrical resistivity

    NARCIS (Netherlands)

    Polder, R.B.; Peelen, W.H.A.

    2002-01-01

    Concrete prisms were made with four cement types including cements with fly ash and/or blast furnace slag and three waterto- cement (w/c) ratios. Chloride penetration and corrosion of rebars were stimulated by subjecting prisms to cyclic loading with salt solution and drying. Concrete resistivity,

  7. Influence of the porosity on the

    NARCIS (Netherlands)

    Jong, P. de; Dijk, W. van; Rooij, M. de

    2011-01-01

    The composition of 23 concrete mixtures was varied in five separate series to evaluate the influence of porosity on the 222Rn exhalation rate. In each series, a range in porosities is obtained by varying (1) the amount of cement, (2) type of cement (Portland or blast furnace slag cement),

  8. Data-Driven Robust RVFLNs Modeling of a Blast Furnace Iron-Making Process Using Cauchy Distribution Weighted M-Estimation

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Ping; Lv, Youbin; Wang, Hong; Chai, Tianyou

    2017-09-01

    Optimal operation of a practical blast furnace (BF) ironmaking process depends largely on a good measurement of molten iron quality (MIQ) indices. However, measuring the MIQ online is not feasible using the available techniques. In this paper, a novel data-driven robust modeling is proposed for online estimation of MIQ using improved random vector functional-link networks (RVFLNs). Since the output weights of traditional RVFLNs are obtained by the least squares approach, a robustness problem may occur when the training dataset is contaminated with outliers. This affects the modeling accuracy of RVFLNs. To solve this problem, a Cauchy distribution weighted M-estimation based robust RFVLNs is proposed. Since the weights of different outlier data are properly determined by the Cauchy distribution, their corresponding contribution on modeling can be properly distinguished. Thus robust and better modeling results can be achieved. Moreover, given that the BF is a complex nonlinear system with numerous coupling variables, the data-driven canonical correlation analysis is employed to identify the most influential components from multitudinous factors that affect the MIQ indices to reduce the model dimension. Finally, experiments using industrial data and comparative studies have demonstrated that the obtained model produces a better modeling and estimating accuracy and stronger robustness than other modeling methods.

  9. Influences of Steelmaking Slags on Hydration and Hardening of Concretes

    Science.gov (United States)

    Kirsanova, A. A.; Dildin, A. N.; Maksimov, S. P.

    2017-11-01

    It is shown that the slag of metallurgical production can be used in the construction industry as an active mineral additive for concrete. This approach allows us to solve environmental problems and reduce costs for the production of binder and concrete simultaneously. Most often slag is used in the form of a filler, an active mineral additive or as a part of a binder for artificial conglomerates. The introduction of slag allows one to notice a part of the cement, to obtain concretes that are more resistant to the impact of aggressive sulfate media. The paper shows the possibility of using recycled steel-smelting slags in the construction industry for the production of cement. An assessment was made of their effect on the hydration of the cement stone and hardening of the concrete together with the plasticizer under normal conditions. In the process of work, we used the slag of the Zlatoust Electrometallurgical Factory. Possible limitations of the content of steel-slag slag in concrete because of the possible presence of harmful impurities are shown. It is necessary to enter slag in conjunction with superplasticizers to reduce the flow of water mixing. Slags can be used as a hardening accelerator for cement concrete as they allow one to increase the degree of cement hydration and concrete strength. It is shown that slags can be used to produce fast-hardening concretes and their comparative characteristics with other active mineral additives are given.

  10. Integrated carbon dioxide/sludge gasification using waste heat from hot slags: syngas production and sulfur dioxide fixation.

    Science.gov (United States)

    Sun, Yongqi; Zhang, Zuotai; Liu, Lili; Wang, Xidong

    2015-04-01

    The integrated CO2/sludge gasification using the waste heat in hot slags, was explored with the aim of syngas production, waste heat recovery and sewage sludge disposal. The results demonstrated that hot slags presented multiple roles on sludge gasification, i.e., not only a good heat carrier (500-950 °C) but also an effective desulfurizer (800-900 °C). The total gas yields increased from 0.022 kg/kgsludge at 500 °C to 0.422 kg/kgsludge at 900 °C; meanwhile, the SO2 concentration at 900 °C remarkably reduced from 164 ppm to 114 ppm by blast furnace slags (BFS) and 93 ppm by steel slags (SS), respectively. A three-stage reaction was clarified including volatile release, char transformation and fixed carbon using Gaussian fittings and the kinetic model was analyzed. Accordingly, a decline process using the integrated method was designed and the optimum slag/sludge ratio was deduced. These deciphered results appealed potential ways of reasonable disposal of sewage sludge and efficient recovery of waste heat from hot slags. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Reatividade de escórias silicatadas da indústria siderúrgica Reactivity of silicate slags of the iron and steel industry

    Directory of Open Access Journals (Sweden)

    Hamilton Seron Pereira

    2010-04-01

    Full Text Available As escórias siderúrgicas são usadas na agricultura, mas são poucos os trabalhos sobre sua reatividade. Neste trabalho, objetivou-se avaliar escórias siderúrgicas em diferentes frações granulométricas quanto à correção do pH e liberação de Ca, Mg e Si para o solo. O delineamento foi inteiramente casualizado com 4 repetições em esquema fatorial com 6 fontes (escória de alto-forno 1, escória de fosfato, escória de alto-forno 2, escória de aciaria de forno AOD, escória de aço inox e escória de forno LD e 5 distribuições granulométricas (2 - 1,41; 1,41 - 0,85; 0,85 - 0,50; 0,50 - 0,30 mm e The slags are used in the agriculture as soil acidity correctives in same rates of lime, but there are few studies about its reactivity in soils. The objective was to compare slag reactivity to soil acidity correction and calcium, magnesium, and silicon liberation. A completely randomized experimental design was used, with 4 repetitions in factorial with 6 sources (blast furnace slag 1, phosphate slag, blast furnace slag 2, AOD furnace steel slag, stainless steel slag and LD furnace steel slag and 5 particle sizes (2-1.41; 1.41-0.85; 0.85-0.50; 0.50-0.30 mm and < 0,30 mm and two additional treatments (control and CaCO3. The CaCO3 was used as a pattern for the determination of the reactivity index of each source. All treatments received 1500 mg kg-1 of equivalent CaCO3 and each rate of slags was calculated by its determined neutralization power. The pH-value increased with reduction of particle size in all slags. The phosphate slag showed best efficiency on the liberation of Ca + Mg compared to the calcium carbonate in the granulometrics inferior to 0.5 mm. There was low efficiency in soil acidity correction and liberation of the Ca and Mg in soil to slag of blast furnace. It is necessary to use particles smaller than 0.3 mm to improve silicon availability of phosphate slag and particles between 0.85 and 1.41mm to stainless steel slag. The

  12. Utilization of municipal solid waste incineration (MSWI) fly ash in blended cement Part 1: Processing and characterization of MSWI fly ash.

    Science.gov (United States)

    Aubert, J E; Husson, B; Sarramone, N

    2006-08-25

    This paper is the first of a series of two articles dealing with the processes applied to MSWI fly ash with a view to reusing it safely in cement-based materials. Part 1 presents two stabilization processes and Part 2 deals with the use of the two treated fly ashes (TFA) in mortars. Two types of binder were used: an Ordinary Portland Cement (OPC) containing more than 95% clinker (CEM I 52.5R) and a binary blend cement composed of 70% ground granulated blast furnace slag and 30% clinker (CEM III-B 42.5N). In this first part, two stabilization processes are presented: the conventional process, called "A", based on the washing, phosphation and calcination of the ash, and a modified process, called "B", intended to eliminate metallic aluminum and sulfate contained in the ash. The physical, chemical and mineralogical characteristics of the two TFA were comparable. The main differences observed were those expected, i.e. TFA-B was free of metallic aluminum and sulfate. The mineralogical characterization of the two TFAs highlighted the presence of large amounts of a calcium aluminosilicate phase taking two forms, a crystalline form (gehlenite) and an amorphous form. Hydration studies on pastes containing mixed TFA and calcium hydroxide showed that this phase reacted with calcium hydroxide to form calcium aluminate hydrates. This formation of hydrates was accompanied by a hardening of the pastes. These results are very encouraging for the reuse of such TFA in cement-based materials because they can be considered as pozzolanic additions and could advantageously replace a part of the cement in cement-based materials. Finally, leaching tests were carried out to evaluate the environmental impact of the two TFAs. The elements which were less efficiently stabilized by process A were zinc, cadmium and antimony but, when the results of the leaching tests were compared with the thresholds of the European landfill directive, TFA-A could nevertheless be accepted at landfills for non

  13. Data-Driven Robust M-LS-SVR-Based NARX Modeling for Estimation and Control of Molten Iron Quality Indices in Blast Furnace Ironmaking.

    Science.gov (United States)

    Zhou, Ping; Guo, Dongwei; Wang, Hong; Chai, Tianyou

    2017-09-29

    Optimal operation of an industrial blast furnace (BF) ironmaking process largely depends on a reliable measurement of molten iron quality (MIQ) indices, which are not feasible using the conventional sensors. This paper proposes a novel data-driven robust modeling method for the online estimation and control of MIQ indices. First, a nonlinear autoregressive exogenous (NARX) model is constructed for the MIQ indices to completely capture the nonlinear dynamics of the BF process. Then, considering that the standard least-squares support vector regression (LS-SVR) cannot directly cope with the multioutput problem, a multitask transfer learning is proposed to design a novel multioutput LS-SVR (M-LS-SVR) for the learning of the NARX model. Furthermore, a novel M-estimator is proposed to reduce the interference of outliers and improve the robustness of the M-LS-SVR model. Since the weights of different outlier data are properly given by the weight function, their corresponding contributions on modeling can properly be distinguished, thus a robust modeling result can be achieved. Finally, a novel multiobjective evaluation index on the modeling performance is developed by comprehensively considering the root-mean-square error of modeling and the correlation coefficient on trend fitting, based on which the nondominated sorting genetic algorithm II is used to globally optimize the model parameters. Both experiments using industrial data and industrial applications illustrate that the proposed method can eliminate the adverse effect caused by the fluctuation of data in BF process efficiently. This indicates its stronger robustness and higher accuracy. Moreover, control testing shows that the developed model can be well applied to realize data-driven control of the BF process.

  14. Nanosized zero-valent iron as Fenton-like reagent for ultrasonic-assisted leaching of zinc from blast furnace sludge

    Energy Technology Data Exchange (ETDEWEB)

    Mikhailov, Ivan, E-mail: ivan.mikhailov@misis.ru [National University of Science and Technology “MISiS”, 4 Leninskiy prospekt, Moscow, 119049 (Russian Federation); Komarov, Sergey [Tohoku University, 6-6-02 Aramaki Aza Aoba, Aoba-ku, Sendai, 980-8576 (Japan); Levina, Vera; Gusev, Alexander; Issi, Jean-Paul; Kuznetsov, Denis [National University of Science and Technology “MISiS”, 4 Leninskiy prospekt, Moscow, 119049 (Russian Federation)

    2017-01-05

    Highlights: • nZVI is used as Fenton-like reagent for activation of Zn leaching from the BFS. • nZVI has positive effect on kinetics of Zn leaching though with some loss of efficiency. • A complex ultrasonic-assisted method for BFS recycling is proposed. - Abstract: Ultrasonic-assisted sulphuric acid leaching combined with a Fenton-like process, utilizing nanoscale zero-valent iron (nZVI), was investigated to enhance the leaching of zinc from the blast furnace sludge (BFS). The leaching of iron (Fe) and zinc (Zn) from the sludge was investigated using Milli-Q water/BFS ratio of 10 and varying the concentration of hydrogen peroxide, sulphuric acid, the temperature, the input energy for ultrasound irradiation, and the presence or absence of nZVI as a Fenton reagent. The results showed that with 1 g/l addition of nZVI and 0.05 M of hydrogen peroxide, the kinetic rate of Zn leaching increased with a maximum dissolution degree of 80.2%, after 5 min treatment. In the absence of nZVI, the maximum dissolution degree of Zn was 99.2%, after 15 min treatment with 0.1 M of hydrogen peroxide. The rate of Zn leaching at several concentrations of hydrogen peroxide is accelerated in the presence of nZVI although a reduction in efficiency was observed. The loss of Fe was no more than 3%. On the basis of these results, the possible route for BFS recycling has been proposed (BFS slurry mixed with sulphuric acid and hydrogen peroxide is recirculated under ultrasonic irradiation then separated).

  15. Study of Early Age Properties and Behaviour of Concrete with GGBS ...

    African Journals Online (AJOL)

    Ground granulated blast furnace slag (GGBS) is used as alternative binder material for cement in the concrete. The use of GGBS in concrete production contributes to the savings of natural resources and energy spent in cement manufacturing process and also to reduce CO2 emissions and environmental impact.

  16. Author Details

    African Journals Online (AJOL)

    Delport, DJ. Vol 64 (2011) - Articles Chloride-binding Effect of Blast Furnace Slag in Cement Pastes Containing Added Chlorides Abstract PDF · Vol 64 (2011) - Articles Potentiometric Determination of Free Chloride in Cement Paste – an Alternative Method for Low-Budget Laboratories Abstract PDF. ISSN: 0379-4350.

  17. Effect of mineral admixtures on kinetic property and compressive strength of self Compacting Concrete

    Science.gov (United States)

    Jagalur Mahalingasharma, Srishaila; Prakash, Parasivamurthy; Vishwanath, K. N.; Jawali, Veena

    2017-06-01

    This paper presents experimental investigations made on the influence of chemical, physical, morphological and mineralogical properties of mineral admixtures such as fly ash, ground granulate blast furnace slag, metakaoline and micro silica used as a replacement of cement in self compacting concrete on workability and compressive strength. Nineteen concrete mixes were cast by replacing with cement by fly ash or ground granulated blast furnace slag as binary blend at 30%, 40%, 50% and with addition of micro silica and metakaoline at 10% as a ternary blend with fly ash, ground granulated blast furnace slag and obtained results were compare with control mix. Water powder ratio 0.3 and super plasticizer dosage 1% of cementitious material was kept constant for all the mixes. The self compacting concrete tested for slump flow, V-funnel, L-Box, J-Ring, T50, and compressive strength on concrete cube were determined at age of 3, 7, 28, 56, 90 days.

  18. Design and Implementation of Alkali Activated Cement For Sustainable Development

    Science.gov (United States)

    Moseson, Alexander James

    Herein, progress is presented on the design and implementation of technology for sustainable development in general and international development in particular. Necessarily interdisciplinary, the work draws upon the tools and techniques of Mechanical, Materials, and Civil Engineering; and History & Politics. The work was conducted along two paths, the first being the theory and methodology of sustainable development. A flexible design and dissemination framework was developed, Technology Seeding, defined as: development by the transfer and participatory adaptation of appropriate proven conceptual designs. The methodology was developed in part through two case studies which implemented, respectively, wood-turning lathes in Tanzania and upland rice planters in Thailand. The second path is the design and investigation of alkali-activated cements (AACs) for practical use. Those developed herein, for US markets, comprise ground granulated blast furnace slag, soda ash (sodium carbonate), and up to 68 wt.% granular limestone. Mixture Design of Experiment (DOE) was utilized to guide empirical and theoretical analysis of performance (e.g. compressive strength), economic & ecological aspects (e.g. cost, CO2 production, energy consumption), and chemistry (e.g. Rietveld analysis of x-ray diffractograms). Models were derived to understand the impact of mix design on performance and for optimization. Successful formulations are hydraulic and cure at room temperature, with strengths as high as 41 MPa at 3 days and 65 MPa at 28 days. Some of these formulations, compared to OPC, are competitive in performance, reduce cost by up to 40%, and reduce both CO2 production and energy consumption by up to 97%. Major chemical products include calcium silicate hydrates / calcium aluminum silicate hydrates (C-(A)-S-H), gaylussite, and calcite (both newly formed and remaining from limestone). Calcite/dolomite and C-(A)-S-H both contribute to strength. A fraction of the limestone is consumed

  19. Effect of wet curing duration on durability parameters of hydraulic cement concretes.

    Science.gov (United States)

    2010-01-01

    Hydraulic cement concrete slabs were cast and stored outdoors in Charlottesville, Virginia, to study the impact of wet curing duration on durability parameters. Concrete mixtures were produced using portland cement, portland cement with slag cement, ...

  20. Verification of Steelmaking Slags Iron Content Final Technical Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    J.Y. Hwang

    2006-10-04

    The steel industry in the United States generates about 30 million tons of by-products each year, including 6 million tons of desulfurization and BOF/BOP slag. The recycling of BF (blast furnace) slag has made significant progress in past years with much of the material being utilized as construction aggregate and in cementitious applications. However, the recycling of desulfurization and BOF/BOP slags still faces many technical, economic, and environmental challenges. Previous efforts have focused on in-plant recycling of the by-products, achieving only limited success. As a result, large amounts of by-products of various qualities have been stockpiled at steel mills or disposed into landfills. After more than 50 years of stockpiling and landfilling, available mill site space has diminished and environmental constraints have increased. The prospect of conventionally landfilling of the material is a high cost option, a waste of true national resources, and an eternal material liability issue. The research effort has demonstrated that major inroads have been made in establishing the viability of recycling and reuse of the steelmaking slags. The research identified key components in the slags, developed technologies to separate the iron units and produce marketable products from the separation processes. Three products are generated from the technology developed in this research, including a high grade iron product containing about 90%Fe, a medium grade iron product containing about 60% Fe, and a low grade iron product containing less than 10% Fe. The high grade iron product contains primarily metallic iron and can be marketed as a replacement of pig iron or DRI (Direct Reduced Iron) for steel mills. The medium grade iron product contains both iron oxide and metallic iron and can be utilized as a substitute for the iron ore in the blast furnace. The low grade iron product is rich in calcium, magnesium and iron oxides and silicates. It has a sufficient lime value and

  1. Integrated biomass gasification using the waste heat from hot slags: Control of syngas and polluting gas releases

    International Nuclear Information System (INIS)

    Sun, Yongqi; Seetharaman, Seshadri; Liu, Qianyi; Zhang, Zuotai; Liu, Lili; Wang, Xidong

    2016-01-01

    In this study, the thermodynamics of a novel strategy, i.e., biomass/CO 2 gasification integrated with heat recovery from hot slags in the steel industry, were systemically investigated. Both the target syngas yield and the polluting gas release were considered where the effect of gasifying conditions including temperature, pressure and CO 2 reacted was analyzed and then the roles of hot slags were further clarified. The results indicated that there existed an optimum temperature for the maximization of H 2 production. Compared to blast furnace slags, steel slags remarkably increased the CO yield at 600–1400 °C due to the existence of iron oxides and decreased the S-containing gas releases at 400–700 °C, indicating potential desulfurizing ability. The identification of biomass/CO 2 gasification thermodynamics in presence of slags could thus provide important clues not only for the deep understanding of biomass gasification but also for the industrial application of this emerging strategy from the viewpoint of syngas optimization and pollution control. - Highlights: • Biomass/CO 2 gasification was integrated with the heat recovery from hot slags. • Both syngas yield and polluting gas release during gasification were determined. • There existed an optimum temperature for the maximization of H 2 production. • Steel slags increased CO yield at 600–1400 °C due to the existence of iron oxides. • Steel slags remarkably decreased the releases of S-containing gas at 400–700 °C.

  2. The influence of metakaolin substitution by slag in alkali-activated inorganic binders for civil engineering

    Science.gov (United States)

    Kadlec, J.; Rieger, D.; Kovářík, T.; Novotný, P.; Franče, P.; Pola, M.

    2017-02-01

    In this study the effect of metakaolin replacement by milled blast furnace slag in alkali-activated geopolymeric binder was investigated in accordance to their rheological and mechanical properties. It was demonstrated that slag addition into the metakaolin binder can improve mechanical properties of final products. Our investigation was focused on broad interval of metakaolin substitution in the range from 100 to 40 volume per cents of metakaolin so that the volume content of solids in final binder was maintained constant. Prepared binders were activated by alkaline solution of potassium silicate with silicate module of 1.61. The particle size analyses were performed for determination of particle size distribution. The rheological properties were determined in accordance to flow properties by measurements on Ford viscosity cup and by oscillatory measurements of hardening process. For the investigation of hardening process, the strain controlled small amplitude oscillatory rheometry was used in plane-plate geometry. For determination of applied mechanical properties were binders filled by ceramic grog in the granularity range 0-1 mm. The filling was maintained constant at 275 volume per cents in accordance to ratio of solids in dry binder. The mechanical properties were investigated after 1, 7 and 28 days and microstructure was documented by scanning electron microscopy. The results indicate that slag addition have beneficial effect not only on mechanical properties of hardened binder but also on flow properties of fresh geopolymer paste and subsequent hardening kinetics of alkali-activated binders.

  3. Effect of polycarboxylate admixture structure on cement paste rheology

    Directory of Open Access Journals (Sweden)

    Aranda, M. A. G.

    2007-06-01

    Full Text Available The purpose of the present study was to analyze the effect of the structural differences in four polycarboxylate and polyether admixtures on the rheological properties of cement pastes with different chemical and mineralogical compositions and different active additions (CEM I 42.5 R, CEM I 52.5 R, CEM I 52.5 N/SR, CEM II/AV 42.5R, CEM II/B-L 32.5 R, CEM III/B 32.5R, BL I 52.5R and CAC – European standard EN 197-1:2000. The results of the minislump test concurred with the variations observed in the values of the rheological parameters (shear stress and plastic viscosity. The structural characteristic of the admixtures found to play the most prominent role in their fluidizing effect was the proportion of carboxylate (CG and polyether (EG group components. In cements characteristics such as fineness and the C3A/calcium sulphate and C3S/C3A ratios were also observed to be essential to admixture effectiveness. In this regard, the rheological parameters varied most widely in CEM I 52.5N/SR pastes and least in BL I 52.5R cement pastes. Of the additioned cements, the CEM III/B 32.5R pastes, which contained granulated blast furnace slag, showed the highest rises in flowability. Finally, the fluidizing effect of polycarboxylate superplasticizers was much more intense in calcium aluminate cements, although flowability declined rapidly in this material.El objetivo de este trabajo ha sido estudiar el efecto de las diferencias estructurales de cuatro aditivos basados en policarboxilatos y poliéteres sobre las propiedades reológicas de pastas de cemento con diferente composición química, mineralógica y con distintas adiciones activas (CEM I 42,5 R, CEM I 52,5 R, CEM I 52,5 N/SR, CEM II/AV 42,5R, CEM II/ B-L 32,5 R, CEM III/B 32,5R, BL I 52,5R y CAC - Norma EN 197-1:2000. Los resultados obtenidos sobre la fluidez de la pasta en el ensayo del “Minislump” coinciden con la evolución de los valores de los parámetros reológicos (esfuerzo de

  4. Results of the freeze resistance test, swelling index and coefficient of permeability of finegrained mining waste reinforced with cements

    Science.gov (United States)

    Morman, Justyna

    2018-04-01

    The article presents the result of laboratory tests for mining waste with grain size of 0 to 2 mm stabilized with cement. Used for stabilization of cement CEM I 42.5 R and blast furnace cement CEM III / A 42.5N - LH / HSR / NA and a plasticizer sealant. Cement was added to the mining waste test in the proportions of 5 - 8% in relation to the skeleton's weight. For the cemented samples, the freeze resistance test, swelling index, coefficient of permeability and pH of water leachate were tested. The addition of a cement binder resulted in diminishing the water permeability of mining waste and limiting the leaching of fine particles from the material.

  5. Carbon Dioxide Emission Evaluation of Porous Vegetation Concrete Blocks for Ecological Restoration Projects

    Directory of Open Access Journals (Sweden)

    Hwang-Hee Kim

    2017-02-01

    Full Text Available The purpose of this study is to determine the mix proportions that can minimize CO2 emissions while satisfying the target performance of porous vegetation concrete. The target performance of porous vegetation concrete was selected as compressive strength (>15 MPa and void ratio (>25%. This study considered the use of reinforcing fiber and styrene butadiene (SB latex to improve the strength of porous vegetation concrete, as well as the use of blast furnace slag aggregate to improve the CO2 emissions-reducing effect, and analyzed and evaluated the influence of fiber reinforcing, SB latex, and blast furnace slag aggregate on the compressive strength and CO2 emissions of porous vegetation concrete. The CO2 emissions of the raw materials were highest for cement, followed by aggregate, SB latex, and fiber. Blast furnace slag aggregate showed a 30% or more CO2 emissions-reducing effect versus crushed aggregate, and blast furnace slag cement showed a 78% CO2 emissions-reducing effect versus Portland cement. The CO2 emissions analyses for each raw material showed that the CO2 emissions during transportation were highest for the aggregate. Regarding CO2 emissions in each production stage, the materials stage produced the highest CO2 emissions, while the proportion of CO2 emissions in the transportation stage for each raw material, excluding fiber, were below 3% of total emissions. Use of blast furnace slag aggregate in porous vegetation concrete produced CO2 emissions-reducing effects, but decreased its compressive strength. Use of latex in porous vegetation concrete improved its compressive strength, but also increased CO2 emissions. Thus, it is appropriate to use latex in porous vegetation concrete to improve its strength and void ratio, and to use a blast furnace slag aggregate replacement ratio of 40% or less.

  6. Environmental characteristics and utilization potential of metallurgical slag: Chapter 19

    Science.gov (United States)

    Piatak, Nadine; De Vivo, Benedetto; Belkin, Harvey E.; Lima, Annamaria

    2018-01-01

    Slag, an abundant byproduct from the pyrometallurgical processing of ores, can be an environmental liability or a valuable resource. The most common environmental impact of slag is from the leaching of potentially toxic elements, acidity, or alkalinity that may impact nearby soils and surface water and groundwater. Factors that influence its environmental behavior include physical characteristics, such as grain size and porosity, chemical composition with some slag being enriched in certain elements, the mineralogy and partitioning of elements in more or less reactive phases, water-slag interactions, and site conditions. Many of these same factors also influence its resource potential. For example, crystalline ferrous slag is most commonly used as construction aggregate, whereas glassy (i.e., granulated) slag is used in cement. Also, the calcium minerals found in ferrous slag result in useful applications in water treatment. In contrast, the high trace-element content of some base-metal slags makes the slags economically attractive for extraction of residual elements. An evaluation tool is used to help categorize a particular slag as an environmental hazard or valuable byproduct. Results for one type of slag, legacy steelmaking slag from the Chicago area in the USA, suggest the material has potential to be used for treating phosphate-rich or acidic waters; however, the pH and trace-element content of resulting solutions may warrant further examination.

  7. Evaluation of the suitability of tin slag in cementitious materials: Mechanical properties and Leaching behaviour

    Science.gov (United States)

    Rustandi, Andi; Wafa’ Nawawi, Fuad; Pratesa, Yudha; Cahyadi, Agung

    2018-01-01

    Tin slag, a by-product of tin production has been used in cementitious application. The present investigation focuses on the suitability of tin slag as primary component in cement and as component that substitute some amount of Portland Cement. The tin slags studied were taken from Bangka, Indonesia. The main contents of the tin slag are SiO2, Al2O3, and Fe2O3 according to the XRF investigation. The aim of this article was to study the mechanical behaviour (compressive strength), microstructure and leaching behaviour of tin slag blended cement. This study used air-cooled tin slag that had been passed through 400# sieve to replace Portland Cement with ratio 0, 10, 20, 30, 40 by weight. Cement pastes and tin slag blended cement pastes were prepared by using water/cement ratio (W/C) of 0.40 by weight and hydrated for various curing ages of 3, 7, 14 days The microstructure of the raw tin slag was investigated using Scanning Electron Microscope (SEM). The phase composition of each cement paste was investigated using X-ray Diffraction (XRD). The aim of the leachability test was to investigate the environmental impacts of tin slag blended cement product in the range 4-8 pH by using static pH-dependent leaching test. The result show that the increase of the tin slag content decreasing the mortar compressive strength at early ages. The use of tin slag in cement provide economic benefits for all related industries.

  8. suitability of electric arc furnace (eaf) slag as partial replacement for ...

    African Journals Online (AJOL)

    Administrator

    The use of Electric Arc Furnace (EAF) Slag which is a by-product solid waste in Steel Production was investigated for use as a partial replacement for cement in sandcrete blocks. The tests carried out on cement and finely ground slag to determine their compositions and physico-chemical properties as well as the evaluation ...

  9. Suitability of electric arc furnace (eaf) slag as partial replacement for ...

    African Journals Online (AJOL)

    The use of Electric Arc Furnace (EAF) Slag which is a by-product solid waste in Steel Production was investigated for use as a partial replacement for cement in sandcrete blocks. The tests carried out on cement and finely ground slag to determine their compositions and physico-chemical properties as well as the evaluation ...

  10. Author Details

    African Journals Online (AJOL)

    Verryn, S. Vol 64 (2011) - Articles Chloride-binding Effect of Blast Furnace Slag in Cement Pastes Containing Added Chlorides Abstract PDF. ISSN: 0379-4350. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and ...

  11. Durability of marine concrete structures - field investigations and modelling

    NARCIS (Netherlands)

    Polder, R.B.; Rooij, M.R. de

    2005-01-01

    This article presents a series of investigations on six concrete structures along the North Sea coast in The Netherlands. They had ages between 18 and 41 years and most of them were made using Blast Furnace Slag cement. Visual inspections showed corrosion damage in only one structure, related to

  12. Durability of marine concrete structures - field investigations and modelling

    NARCIS (Netherlands)

    Polder, R.B.; Rooij, M.R. de

    2006-01-01

    This article presents a series of investigations on six concrete structures along the North Sea coast in The Netherlands. They had ages between 18 and 41 years and most of them were made using Blast Furnace Slag cement. Visual inspections showed corrosion damage in only one structure, related to

  13. Immobilisation of lead smelting slag within spent aluminate-fly ash based geopolymers.

    Science.gov (United States)

    Ogundiran, M B; Nugteren, H W; Witkamp, G J

    2013-03-15

    This study presents the solidification/stabilisation and immobilisation of lead smelting slag (LSS) by its incorporation in coal fly ash - blast furnace slag based geopolymers. It also explores the use of a spent aluminium etching solution (AES) as geopolymer activator instead of the commonly used silicate solutions. The compressive strength of the geopolymers produced with the AES was lower than when applying a K-silicate solution as activator (100MPa versus 80MPa after 28 days). Compressive strength was not affected when up to 10% of the FA was replaced by LSS. NEN 12457-4, TCLP, SPLP and NEN 7375 leaching tests indicated that mobile Pb from LSS was highly immobilised. The diffusion leaching test NEN 7375 revealed exceeding of the Dutch Soil Quality Regulation threshold limits only for Se and Sb. On the condition that the remaining excess leaching can be reduced by further refinement of the mixture recipes, the proposed process will have the potential of producing waste-based construction materials that may be applied under controlled conditions in specific situations. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Análise fluido-dinâmica do escoamento em ensaio de permeabilidade ao ar de argamassas preparadas com cimento Portland de alto-forno Fluid-dynamic analysis of the flow in air permeability measurement of mortars prepared with blast-slag furnace Portland cement

    Directory of Open Access Journals (Sweden)

    V. M. Pereira

    2008-06-01

    . These studies not only have evaluated the permeability of porous media, but also to analyze the behavior of the fluid during the flow. Being about to the cement based materials, the measuring of the permeability becomes basic so that the durability of these can be estimate, therefore is the permeability that controls the rate of ingression and movement of deleterious agents inside these materials. Thus, diverse methodologies and mathematical equations have been used to foresee the permeability of cementitious materials, however, some discrepancies and nonsense in the results have been found. Amongst the used methodologies to measure the permeability of porous media, one meets developed it by Thenoz, which it has demonstrated good results in cement based materials. Thus, this work aims at, by means of assay of permeability to air, carried through in accordance with the methodology of Thenoz, to evaluate the fluid-dynamic behavior of air during the assay of permeability in mortars. For this, mortars prepared with two types of Portland cement of blast furnace (CP IIE-32 and CP III - 32, two relations water/cement (0.5 and 0.6 and ages of 14 and 28 days were used. By means of the gotten results it was possible to observe that during the draining the compressibility of air can be ignored, the regimen of draining can be considered as to plate, demonstrating that the methodology proposal for Thenoz and used mathematical equations can result in coefficients of trustworthy air permeability, therefore phenomena and considerations that could influence in this type of flow can be neglected, in accordance with what it is considered by literature.

  15. Hydration characteristics and environmental friendly performance of a cementitious material composed of calcium silicate slag

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Na; Li, Hongxu [School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Beijing Key Laboratory of Rare and Precious Metals Green Recycling and Extraction, University of Science and Technology Beijing, Beijing 100083 (China); Zhao, Yazhao [School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Liu, Xiaoming, E-mail: liuxm@ustb.edu.cn [School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Beijing Key Laboratory of Rare and Precious Metals Green Recycling and Extraction, University of Science and Technology Beijing, Beijing 100083 (China)

    2016-04-05

    Highlights: • Cementitious material was designed according to [SiO{sub 4}] polymerization degree of raw materials. • The cementitious material composed of calcium silicate slag yields excellent physical and mechanical properties. • Amorphous C–A–S–H gel and rod-like ettringite are predominantly responsible for the strength development. • Leaching toxicity and radioactivity tests show the cementitious material is environmentally acceptable. - Abstract: Calcium silicate slag is an alkali leaching waste generated during the process of extracting Al{sub 2}O{sub 3} from high-alumina fly ash. In this research, a cementitious material composed of calcium silicate slag was developed, and its mechanical and physical properties, hydration characteristics and environmental friendly performance were investigated. The results show that an optimal design for the cementitious material composed of calcium silicate slag was determined by the specimen CFSC7 containing 30% calcium silicate slag, 5% high-alumina fly ash, 24% blast furnace slag, 35% clinker and 6% FGD gypsum. This blended system yields excellent physical and mechanical properties, confirming the usefulness of CFSC7. The hydration products of CFSC7 are mostly amorphous C–A–S–H gel, rod-like ettringite and hexagonal-sheet Ca(OH){sub 2} with small amount of zeolite-like minerals such as CaAl{sub 2}Si{sub 2}O{sub 8}·4H{sub 2}O and Na{sub 2}Al{sub 2}Si{sub 2}O{sub 8}·H{sub 2}O. As the predominant hydration products, rod-like ettringite and amorphous C–A–S–H gel play a positive role in promoting densification of the paste structure, resulting in strength development of CFSC7 in the early hydration process. The leaching toxicity and radioactivity tests results indicate that the developed cementitious material composed of calcium silicate slag is environmentally acceptable. This study points out a promising direction for the proper utilization of calcium silicate slag in large quantities.

  16. Alkali silica reaction (ASR) in cement free alkali activated sustainable concrete.

    Science.gov (United States)

    2016-12-19

    This report summarizes the findings of an experimental evaluation into alkali silica : reaction (ASR) in cement free alkali-activated slag and fly ash binder concrete. The : susceptibility of alkali-activated fly ash and slag concrete binders to dele...

  17. Cement matrix composite construction features for production of waterproofing coatings

    OpenAIRE

    Суханевич, Марина Володимирівна

    2014-01-01

    It is investigated the properties of the matrix based on Portland cement, slag-contain and fly-ash- slag-contain cements modified with the addition of natural zeolite and complex additives consisting of carbon nanotubes in C-3 solution plasticizer as the main component of composite waterproofing material that is applied to wet concrete in the form of thin-layer coatings.

  18. Mechanical strength of extrusion briquettes (brex) for blast-furnace and ferroalloy production: I. dependence of the strength properties of extrusion briquettes on the binder

    Science.gov (United States)

    Bizhanov, A. M.; Kurunov, I. F.; Dashevskii, V. Ya.

    2015-03-01

    The efficiency of preliminary homogenization of a briquetted charge using bentonite is shown. The dynamics of increasing the strength of commercial extrusion briquettes (brex) during storage under natural conditions is studied. A combined cement-bentonite binder is used to reveal a new effect of local maximum of the cold strength of brex at the third day of hardening, which is accompanied by a change in the character of its fracture

  19. Forensic Investigation of AC and PCC Pavements with Extended Service Life : Volume 3 : Petrographic Examination of Blast Furnace Slag Aggregate Concrete Cores taken from PCC Pavements in Cuyahoga County , Ohio

    Science.gov (United States)

    2011-09-01

    The purpose of this research was to identify flexible and rigid pavements in Ohio with average and above average : performance, and determine reasons for these differences in performance. The identification and implementation of : factors linked to e...

  20. Energetic analysis versus exergetic analysis of charcoal blast furnace of V and M do Brazil; Analise energetica versus analise exergetica do alto forno a carvao vegetal da V and M do Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Lis Nunes; Silva, Ricardo Junqueira [V e M do BRASIL S.A., Belo Horizonte, MG (Brazil); Franca, Geraldo Augusto Campolina; Lemos, Ricardo Jose Fernandes [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

    2011-12-21

    The energetic analysis is the traditional method of quantification of the energy used in an operation involving physical and chemical processes and transference and/or conversion of energy. Generally used through energetic balance that is based on the first law of thermodynamics to evaluate the energetic efficiency. This balance is used to determine and reduce the loss of energy. Although an energy balance does not provide information about the energy degradation or resources during a process and do not quantify the potential or quality of the energy fluxes and material that flow in a system and come out as products and losses. The exergetic analysis goes beyond the limitations of the first law of thermodynamics. The concept of exergy is based in the second law of thermodynamics. The objective of this paper is to compare the more suitable analysis method aiming the identification of the energy economy potentials and consequently the reduction in the emissions of the greenhouse gases, through the balance of mass, energy and exergy of the blast furnace 1 of V and M do Brazil. (author)

  1. Topics in cement and concrete research

    OpenAIRE

    Brouwers, Jos; Russel, M.I.; Basheer, P.A.M.

    2007-01-01

    The present paper addresses several topics in regard to the sustainable design and use of concrete. First, major features concerning the sustainable aspects of the material concrete are summarised. Then the major constituent, from an environmental point of view, cement is discussed in detail, particularly the hydration and application of slag cement. The intelligent combining of mineral oxides, which are found in clinker, slag, fly ashes etc., is designated as mineral oxide engineering. It re...

  2. Corrosion Behavior of Carbon Steel in Concrete Material Composed of Tin Slag Waste in Aqueous Chloride Solution

    Science.gov (United States)

    Rustandi, Andi; Cahyadi, Agung; Taruli Siallagan, Sonia; Wafa’ Nawawi, Fuad; Pratesa, Yudha

    2018-01-01

    Tin slag is a byproduct of tin ore smelting process which is rarely utilized. The main purpose of this work is to investigate the use of tin slag for concrete cement material application compared to the industrial Ordinary Portland Cement (OPC). Tin slag composition was characterized by XRD and XRF analysis. The characterization results showed the similar chemical composition of tin slag and OPC. It also revealed the semi crystalline structure of tin slag sample. Several electrochemical tests were performed to evaluate corrosion behavior of tin slag, OPC and various mixed composition of both materials and the addition of CaO. The corrosion behavior of OPC and tin slag were evaluated by using Cyclic Polarization, Electrochemical Impedance Spectroscopy (EIS) and Electrochemical Frequency Modulation (EFM) methods. Aqueous sodium chloride (NaCl) solution with 3.5% w.t concentration which similar to seawater was used as the electrolyte in this work. The steel specimen used as the reinforce bar (rebar) material of the concrete was carbon steel AISI 1045. The rebar was embedded in the concrete cement which composed of OPC and the various composition of tin slag including slag without addition of CaO and slag mixed with addition of 50 % CaO. The electrochemical tests results revealed that tin slag affected its corrosion behavior which becoming more active and increasing the corrosion rate as well as decreasing the electrochemical impedance.

  3. Hydrothermal solidification of municipal solid waste incineration bottom ash with slag addition.

    Science.gov (United States)

    Jing, Zhenzi; Ran, Xianqiang; Jin, Fangming; Ishida, Emile H

    2010-01-01

    Hydrothermal solidification of municipal solid waste incineration (MSWI) bottom ash has been carried out under saturated steam pressure (1.56 MPa) at 200 degrees C for up to 24 h by mixing quartz, slaked lime and water-cooled blast furnace slag (WBFS). The strength enhancement for the WBFS addition was best. The strength development was shown to be due mainly to tobermorite formation, and the tobermorite formation densified matrix, thus promoting the strength development. WBFS seemed to have a higher reactivity than the quartz during the initial hydrothermal process, which provided more silica available to harden the solidified specimens. However, a longer curing time (24 h) was favorable to the quartz dissolution for tobermorite formation, which in turn, enhanced the strength for quartz addition. Curing time affected the crystal morphology evolution, and the stubby plate of tobermorite seemed to result in a high strength enhancement in this study. Laboratory leaching tests were conducted to determine the amount of heavy metals dissolved from the final solidified specimens, and the leaching results showed that after hydrothermal processing the heavy metals dissolved from the solidified specimens were reduced effectively. As such, the hydrothermal processing may have a high potential for recycling/reusing MSWI ash on a large scale. 2010 Elsevier Ltd. All rights reserved.

  4. Extraction of Vanadium from Vanadium Slag Via Non-salt Roasting and Ammonium Oxalate Leaching

    Science.gov (United States)

    Li, Meng; Du, Hao; Zheng, Shili; Wang, Shaona; Zhang, Yang; Liu, Biao; Dreisinger, David Bruce; Zhang, Yi

    2017-10-01

    A clean method featuring non-salt roasting followed by (NH4)2C2O4 leaching to recover vanadium from vanadium slag was proposed. The carcinogenic Cr6+ compounds and exhaust gases were avoided, and the water generated from vanadate precipitation may be recycled and reused in this new leaching process. The leaching residues may be easily used by a blast furnace. Moreover, (NH4)2C2O4 solution was used as a leaching medium to avoid expensive and complicated ammonium controlling operations as a result of the stability of (NH4)2C2O4 at a high temperature. The transformation mechanisms of vanadium- and chromium-bearing phases were systematically investigated by x-ray diffraction analysis and scanning electron microscopy with energy-disperse x-ray spectrometry, respectively. In addition, the effects of oxygen concentration, roasting temperature, and holding time on vanadium recovery were investigated. Finally, the effects of leaching variables on the vanadium leaching rate were also examined.

  5. Rheology of Cementitious Materials: Alkali-Activated Materials or Geopolymers

    OpenAIRE

    Puertas F.; Alonso M.M:; Gismera S.; Lanzón M.; Blanco-Varela M.T.

    2018-01-01

    A clear alternative to reach the goal of sustainable development in the Construction Sector is the development of alternative building materials to Ordinary Portland Cement (OPC) in a more energetically as well as environmentally eco-efficient way. Alkaline cements (Alkali-Activated Materials, AAMs) and geopolymers meet these requirements; and they are based on the alkali activation of aluminosilicates (mainly waste and industrial by-products, such as blast furnace slag, fly ash and ceramic w...

  6. Concrete evidence

    Energy Technology Data Exchange (ETDEWEB)

    Provis, J.; Duxson, P.; van Deventer, J. [University of Melbourne, Vic. (Australia)

    2008-11-15

    The time is right for a revolution in the cement industry which is responsible for 5-8% of all human-derived carbon dioxide emissions. Zeobond, an Australian company, has developed E-Crete which is a geopolymer concrete using fly ash and blast furnace slags which reduces CO{sub 2} emissions by 80% from the 0.67t of CO{sub 2} per ton of cement emitted by the Australian triple blend of cement, fly ash and slag. The article discusses the products development, standards for cements and challenges to the commercialization of E-Crete. 5 refs., 3 figs.

  7. Research on the compressive strength of basic magnesium salts and cyanide slag solidified body

    Science.gov (United States)

    Tu, Yubo; Han, Peiwei; Ye, Shufeng; Wei, Lianqi; Zhang, Xiaomeng; Fu, Guoyan; Yu, Bo

    2018-02-01

    The solidification of cyanide slag by using basic magnesium salts could reduce pollution and protect the environment. Experiments were carried out to investigate the effects of age, mixing amount of cyanide slag, water cement ratio and molar ratio of MgO to MgSO4 on the compressive strength of basic magnesium salts and cyanide slag solidified body in the present paper. It was found that compressive strength of solidified body increased with the increase of age, and decreased with the increase of mixing amount of cyanide slag and water cement ratio. The molar ratio of MgO to MgSO4 should be controlled in the range from 9 to 11 when the mixing amount of cyanide slag was larger than 80 mass%.

  8. Strength and Drying Shrinkage of Alkali-Activated Slag Paste and Mortar

    Directory of Open Access Journals (Sweden)

    Mao-chieh Chi

    2012-01-01

    Full Text Available The aim of this study is to investigate the strengths and drying shrinkage of alkali-activated slag paste and mortar. Compressive strength, tensile strength, and drying shrinkage of alkali-activated slag paste and mortar were measured with various liquid/slag ratios, sand/slag ratios, curing ages, and curing temperatures. Experimental results show that the higher compressive strength and tensile strength have been observed in the higher curing temperature. At the age of 56 days, AAS mortars show higher compressive strength than Portland cement mortars and AAS mortars with liquid/slag ratio of 0.54 have the highest tensile strength in all AAS mortars. In addition, AAS pastes of the drying shrinkage are higher than AAS mortars. Meanwhile, higher drying shrinkage was observed in AAS mortars than that observed comparable Portland cement mortars.

  9. Magnetic spherules from the soils near the slag dump of the Nizhniy Tagil metallurgical plant

    Directory of Open Access Journals (Sweden)

    A. B. Makarov

    2017-12-01

    Full Text Available Magnetic spherules, which are widespread in soils, can have different origins, but spherules with cosmic origin are the most studied. At that, functioning of numerous industrial enterprises of metallurgical profile, thermal power stations, and motor transport can be their origin. According to the data of previous researchers, spherical magnetic particles in soils can serve as an indicator for quantitative assessment of erosion-accumulative phenomena. The authors studied magnetic spherules, isolated from soil samples taken near the dump of blast furnace and metallurgical slags of a large Nizhny Tagil metallurgical plant located on the left bank of the Olkhovka river, functioning since 1949. The way the dump forms is by draining slag along the slope. Consequently, adjacent territories are exposed to a significant dust load, associated with increased concentrations of a number of heavy metals: chromium, iron, manganese, vanadium, copper and zinc. The study of magnetic spherules performed for samples of soils taken at a distance of 50 and 100 m to the west of the dump showed that the content of magnetic fraction in them was 15.1 and 11.7% respectively, of the mineral part of the samples. The authors studied magnetic spherules on a scanning microscope JEOL JSM 6390LV, an at that provide their morphology and the chemical composition of magnetic spherules (18 analyzes and aggregates on their surface (5 analyzes. Based on the presence of characteristic impurity elements, there are the following varieties: zinc, manganese, vanadium, determined by the peculiarities of metallurgical processes. Low concentrations of spherules in soils do not allow considering them as a significant source of pollution of natural environment, only a slight increase in the content of heavy metals characteristic for them is possible.

  10. Preliminary study of tin slag concrete mixture

    Science.gov (United States)

    Hashim, Mohd Jamil; Mansor, Ishak; Pauzi Ismail, Mohamad; Sani, Suhairy; Azmi, Azhar; Sayuti, Shaharudin; Zaidi Ibrahim, Mohd; Adli Anuar, Abul; Rahim, Abdul Adha Abdul

    2018-01-01

    The study focuses on practices to facilitate tin smelting industry to reduce radioactive waste product (Tin Slag) by diluting its radioactivity to a safe level and turning it to a safer infrastructural building product. In the process the concrete mix which include Portland cement, sand, tin slag, water and plasticizer are used to produce interlocking brick pavements, piles and other infrastructural products. The mixing method follows DOE (UK) standard method of mixing targeted at in selected compressive strength suitable for its function and durability. A batching machine is used in the mixing and six test cubes are produced for the test. The testing equipment used are a compressional machine, ultrasonic measurement and a Geiger Muller counter to evaluate of the concrete mix to find the lowest emission of radiation surface dose without compromising the strength of concrete mix. The result obtained indicated the radioactivity of tin slag in the mixing process has reduced to background level that is 0.5μSv/h while the strength and workability of the concrete has not been severely affected. In conclusion, the concrete mix with tin slag has shown the potential it can be turned into a safe beneficial infrastructural product with good strength.

  11. Crystallization phenomena in slags

    Science.gov (United States)

    Orrling, Carl Folke

    2000-09-01

    The crystallization of the mold slag affects both the heat transfer and the lubrication between the mold and the strand in continuous casting of steel. In order for mold slag design to become an engineering science rather than an empirical exercise, a fundamental understanding of the melting and solidification behavior of a slag must be developed. Thus it is necessary to be able to quantify the phenomena that occur under the thermal conditions that are found in the mold of a continuous caster. The double hot thermocouple technique (DHTT) and the Confocal Laser Scanning Microscope used in this study are two novel techniques for investigating melting and solidification phenomena of transparent slags. Results from these techniques are useful in defining the phenomena that occur when the slag film infiltrates between the mold and the shell of the casting. TTT diagrams were obtained for various slags and indicated that the onset of crystallization is a function of cooling rate and slag chemistry. Crystal morphology was found to be dependent upon the experimental temperature and four different morphologies were classified based upon the degree of melt undercooling. Continuous cooling experiments were carried out to develop CCT diagrams and it was found that the amount and appearance of the crystalline fraction greatly depends on the cooling conditions. The DHTT can also be used to mimic the cooling profile encountered by the slag in the mold of a continuous caster. In this differential cooling mode (DCT), it was found that the details of the cooling rate determine the actual response of the slag to a thermal gradient and small changes can lead to significantly different results. Crystal growth rates were measured and found to be in the range between 0.11 mum/s to 11.73 mum/s depending on temperature and slag chemistry. Alumina particles were found to be effective innoculants in oxide melts reducing the incubation time for the onset of crystallization and also extending

  12. Steelmaking slag as aggregate for mortars: effects of particle dimension on compression strength.

    Science.gov (United States)

    Faraone, Nicola; Tonello, Gabriele; Furlani, Erika; Maschio, Stefano

    2009-11-01

    The present paper reports on the results of some experiments obtained from the production, hydration and subsequent measurement of the mechanical properties of several mortars prepared using a commercial CII/B-LL Portland cement, steelmaking slag, superplasticizer and water. Relevant parameters for the mortar preparation are the weight ratios of cement/water, the weight ratio superplasticizer/cement and between fine and granulated coarse particles. It has been demonstrated that optimisation of such parameters leads to the production of materials with mechanical properties suitable for civil engineering applications. Moreover, materials with improved compressive strength can be prepared by the use of slag containing extensive amounts of large particles.

  13. Use of Slag/Sugar Cane Bagasse Ash (SCBA) Blends in the Production of Alkali-Activated Materials.

    Science.gov (United States)

    Castaldelli, Vinícius N; Akasaki, Jorge L; Melges, José L P; Tashima, Mauro M; Soriano, Lourdes; Borrachero, María V; Monzó, José; Payá, Jordi

    2013-07-25

    Blast furnace slag (BFS)/sugar cane bagasse ash (SCBA) blends were assessed for the production of alkali-activated pastes and mortars. SCBA was collected from a lagoon in which wastes from a sugar cane industry were poured. After previous dry and grinding processes, SCBA was chemically characterized: it had a large percentage of organic matter ( ca. 25%). Solutions of sodium hydroxide and sodium silicate were used as activating reagents. Different BFS/SCBA mixtures were studied, replacing part of the BFS by SCBA from 0 to 40% by weight. The mechanical strength of mortar was measured, obtaining values about 60 MPa of compressive strength for BFS/SCBA systems after 270 days of curing at 20 °C. Also, microstructural properties were assessed by means of SEM, TGA, XRD, pH, electrical conductivity, FTIR spectroscopy and MIP. Results showed a good stability of matrices developed by means of alkali-activation. It was demonstrated that sugar cane bagasse ash is an interesting source for preparing alkali-activated binders.

  14. Applicability of alkali activated slag-seeded Egyptian Sinai kaolin for the immobilization of 60Co radionuclide

    International Nuclear Information System (INIS)

    El-Naggar, M.R.

    2014-01-01

    The present work was established to determine the applicability of local Egyptian kaolinite and blast furnace slag (BFS) as raw materials toward the synthesis of geopolymers and subsequent immobilization of cobalt-60, which is one of the most abundant radionuclides generated in radioactive waste streams in Egypt. XRF, XRD, FT-IR, and SEM techniques were used to characterize the local raw materials and their corresponding alkali activated products. Metakaolin (MK) was obtained by thermal treatment of Egyptian Sinai kaolin 750 °C/4 h. MK and five different BFS content (5, 10, 30, 50 and 80%) were used to synthesize geopolymeric matrices using an alkaline activator of Si-modulus = 1.35 at solid/liquid ratios of 0.8. Compressive strength tests were performed indicating that 50% BFS addition gave the highest values of compressive strength. The IAEA standard leaching tests of cobalt-60 from the solidified waste matrices were carried out. The effective diffusion coefficients of cobalt-60 radionuclides from the solidified waste matrices were calculated to be in the order of 10 −14 cm 2 /s. Leaching of radionuclides was examined to be controlled by the wash-off mechanism with very acceptable values. These results gave encouragement that the tested Egyptian raw materials can be conveniently applied for the synthesis of geopolymers that can be used as a low-cost and high-efficiency materials for the immobilization of radioactive waste

  15. Applicability of alkali activated slag-seeded Egyptian Sinai kaolin for the immobilization of {sup 60}Co radionuclide

    Energy Technology Data Exchange (ETDEWEB)

    El-Naggar, M.R., E-mail: elnaggar74@yahoo.com

    2014-04-01

    The present work was established to determine the applicability of local Egyptian kaolinite and blast furnace slag (BFS) as raw materials toward the synthesis of geopolymers and subsequent immobilization of cobalt-60, which is one of the most abundant radionuclides generated in radioactive waste streams in Egypt. XRF, XRD, FT-IR, and SEM techniques were used to characterize the local raw materials and their corresponding alkali activated products. Metakaolin (MK) was obtained by thermal treatment of Egyptian Sinai kaolin 750 °C/4 h. MK and five different BFS content (5, 10, 30, 50 and 80%) were used to synthesize geopolymeric matrices using an alkaline activator of Si-modulus = 1.35 at solid/liquid ratios of 0.8. Compressive strength tests were performed indicating that 50% BFS addition gave the highest values of compressive strength. The IAEA standard leaching tests of cobalt-60 from the solidified waste matrices were carried out. The effective diffusion coefficients of cobalt-60 radionuclides from the solidified waste matrices were calculated to be in the order of 10{sup −14} cm{sup 2}/s. Leaching of radionuclides was examined to be controlled by the wash-off mechanism with very acceptable values. These results gave encouragement that the tested Egyptian raw materials can be conveniently applied for the synthesis of geopolymers that can be used as a low-cost and high-efficiency materials for the immobilization of radioactive waste.

  16. Long term mechanical properties of alkali activated slag

    Science.gov (United States)

    Zhu, J.; Zheng, W. Z.; Xu, Z. Z.; Leng, Y. F.; Qin, C. Z.

    2018-01-01

    This article reports a study on the microstructural and long-term mechanical properties of the alkali activated slag up to 180 days, and cement paste is studied as the comparison. The mechanical properties including compressive strength, flexural strength, axis tensile strength and splitting tensile strength are analyzed. The results showed that the alkali activated slag had higher compressive and tensile strength, Slag is activated by potassium silicate (K2SiO3) and sodium hydroxide (NaOH) solutions for attaining silicate modulus of 1 using 12 potassium silicate and 5.35% sodium hydroxide. The volume dosage of water is 35% and 42%. The results indicate that alkali activated slag is a kind of rapid hardening and early strength cementitious material with excellent long-term mechanical properties. Single row of holes block compressive strength, single-hole block compressive strength and standard solid brick compressive strength basically meet engineering requirements. The microstructures of alkali activated slag are studied by X-ray diffraction (XRD). The hydration products of alkali-activated slag are assured as hydrated calcium silicate and hydrated calcium aluminate.

  17. Behaviour of alkaline cement mortars reinforced with acrylic and polypropylene fibres

    Directory of Open Access Journals (Sweden)

    Puertas, P.

    2000-09-01

    Full Text Available In the present work, the behaviour of alkaline cement mortars reinforced with fibres of different nature (acrylic and polypropylene fibres is studied. Also the chemical stability of those fibres in strong alkaline medium has been investigated. Three different matrixes have been used: glass blast furnace slag activated with NaOH 2M (room temperature, 22 ºC; fly ash activated with NaOH 8M, cured at 85ºC during 24 hours and 50% fly ash / 50% slag activated with NaOH 8M, room temperature. The fibre content was 0,2 and 1% in mortar volume. The tests carried out were: tenacity and tenacity index, impact resistance and drying shrinkage. On the specimens tested, a microstructural study by SEM/EDX was carried out. The results obtained have demonstrated the following: a The acrylic and polypropylene fibres are stable in strong basic media, although the first undergo hydrolysis/ hydration processes showed by the alteration of the surface texture, b with low fibre contents (0,2% in volume, tenacity and tenacity index of these mortars remain unaffected. With higher contents (1%, an increase of the corresponding values is produced. This increment is higher in mortars with alkaline activated slag, c For the three matrixes studied, the polypropylene fibres increase the impact strength in higher degree than the acrylic ones. The reinforcement effect is more significative in matrix A and when the fibre content is 1% in volume, d the shrinkage of these mortars is modified depending on the matrix and fibre type. In mortars of activated slag, fibres do not reduce the shrinkage. In mortars of activated fly ash reinforced with acrylic fibres, shrinkage is lower than those containing polypropylene fibres are. Finally, in mortars of fly ash/ activated slag, the two fibres decrease the drying shrinkage.

    En el presente trabajo se estudia el comportamiento de morteros de cementos alcalinos reforzados con fibras de distinta naturaleza (acrílica y de polipropileno

  18. Effects of Different Mineral Admixtures on the Properties of Fresh Concrete

    OpenAIRE

    Khan, Sadaqat Ullah; Nuruddin, Muhammad Fadhil; Ayub, Tehmina; Shafiq, Nasir

    2014-01-01

    This paper presents a review of the properties of fresh concrete including workability, heat of hydration, setting time, bleeding, and reactivity by using mineral admixtures fly ash (FA), silica fume (SF), ground granulated blast furnace slag (GGBS), metakaolin (MK), and rice husk ash (RHA). Comparison of normal and high-strength concrete in which cement has been partially supplemented by mineral admixture has been considered. It has been concluded that mineral admixtures may be categorized i...

  19. Dispersão e comportamento reológico de concretos refratários ultra-baixo teor de cimento no sistema Al2O3-SiC-SiO2-C Dispersion and setting control of ultra-low cement refractory castables in the Al2O3-SiC-SiO2-C system

    Directory of Open Access Journals (Sweden)

    I. R. de Oliveira

    2003-03-01

    Full Text Available Concretos refratários no sistema Al2O3-SiC-SiO2-C vêm sendo amplamente utilizados em indústrias siderúrgicas como revestimento de canais de corrida de altos-fornos, em virtude principalmente da sua elevada refratariedade aliada a altas resistências ao choque térmico e ao ataque por escória e metal fundido. Neste trabalho, investigou-se a influência de diferentes tipos de aditivos na trabalhabilidade e dispersão de concretos refratários de ultra-baixo teor de cimento nesse sistema. Apesar da sua alta capacidade de complexar íons de cálcio, moléculas de citrato não foram capazes de controlar adequadamente o tempo de pega do concreto estudado, contradizendo a idéia geral de que os íons de citrato devem ser utilizados para controlar a sua trabalhabilidade. Por outro lado, o aditivo polimetacrilato de sódio mostrou-se eficiente na otimização simultânea da dispersão e da trabalhabilidade do concreto devido provavelmente ao retardamento da dissolução dos íons advindos do cimento.Refractory castables in the Al2O3-SiC-SiO2-C system have been extensively used as linings for blast furnace runners, due mainly to their improved resistance to thermal shock damage and to slag and metal corrosion, respectively. In this work, ULC refractory castables in the Al2O3-SiC-SiO2-C system were prepared in order to evaluate the efficiency of different sort of additives on their dispersion and setting behavior. Although citrate ions are known to be efficient chelating agents, they were not able to properly control the working time of the castable studied, contradicting the general idea that citrate ions are necessary for controlling castable setting. On the other hand, the sodium polymethacrylate additive was found to be more efficient for the simultaneous optimization of the castable dispersion state and working time. This may be attributed to a retardation effect imparted by polymethacrylate molecules on the dissolution of ions from the surface

  20. Process envelopes for stabilisation/solidification of contaminated soil using lime-slag blend.

    Science.gov (United States)

    Kogbara, Reginald B; Yi, Yaolin; Al-Tabbaa, Abir

    2011-09-01

    Stabilisation/solidification (S/S) has emerged as an efficient and cost-effective technology for the treatment of contaminated soils. However, the performance of S/S-treated soils is governed by several intercorrelated variables, which complicates the optimisation of the treatment process design. Therefore, it is desirable to develop process envelopes, which define the range of operating variables that result in acceptable performance. In this work, process envelopes were developed for S/S treatment of contaminated soil with a blend of hydrated lime (hlime) and ground granulated blast furnace slag (GGBS) as the binder (hlime/GGBS = 1:4). A sand contaminated with a mixture of heavy metals and petroleum hydrocarbons was treated with 5%, 10% and 20% binder dosages, at different water contents. The effectiveness of the treatment was assessed using unconfined compressive strength (UCS), permeability, acid neutralisation capacity and contaminant leachability with pH, at set periods. The UCS values obtained after 28 days of treatment were up to ∼800 kPa, which is quite low, and permeability was ∼10(-8) m/s, which is higher than might be required. However, these values might be acceptable in some scenarios. The binder significantly reduced the leachability of cadmium and nickel. With the 20% dosage, both metals met the waste acceptance criteria for inert waste landfill and relevant environmental quality standards. The results show that greater than 20% dosage would be required to achieve a balance of acceptable mechanical and leaching properties. Overall, the process envelopes for different performance criteria depend on the end-use of the treated material.

  1. Effect of silicate modulus and metakaolin incorporation on the carbonation of alkali silicate-activated slags

    International Nuclear Information System (INIS)

    Bernal, Susan A.; Mejia de Gutierrez, Ruby; Provis, John L.; Rose, Volker

    2010-01-01

    Accelerated carbonation is induced in pastes and mortars produced from alkali silicate-activated granulated blast furnace slag (GBFS)-metakaolin (MK) blends, by exposure to CO 2 -rich gas atmospheres. Uncarbonated specimens show compressive strengths of up to 63 MPa after 28 days of curing when GBFS is used as the sole binder, and this decreases by 40-50% upon complete carbonation. The final strength of carbonated samples is largely independent of the extent of metakaolin incorporation up to 20%. Increasing the metakaolin content of the binder leads to a reduction in mechanical strength, more rapid carbonation, and an increase in capillary sorptivity. A higher susceptibility to carbonation is identified when activation is carried out with a lower solution modulus (SiO 2 /Na 2 O ratio) in metakaolin-free samples, but this trend is reversed when metakaolin is added due to the formation of secondary aluminosilicate phases. High-energy synchrotron X-ray diffractometry of uncarbonated paste samples shows that the main reaction products in alkali-activated GBFS/MK blends are C-S-H gels, and aluminosilicates with a zeolitic (gismondine) structure. The main crystalline carbonation products are calcite in all samples and trona only in samples containing no metakaolin, with carbonation taking place in the C-S-H gels of all samples, and involving the free Na + present in the pore solution of the metakaolin-free samples. Samples containing metakaolin do not appear to have the same availability of Na + for carbonation, indicating that this is more effectively bound in the presence of a secondary aluminosilicate gel phase. It is clear that claims of exceptional carbonation resistance in alkali-activated binders are not universally true, but by developing a fuller mechanistic understanding of this process, it will certainly be possible to improve performance in this area.

  2. DIE SLAG VAN DOORNKRAAL

    African Journals Online (AJOL)

    Die slag van Doornkraal moet gesien word teen die agtergrond van die ..... saddled and tied to a food wagon. Steyn galloped off, leaving ..... great habit of his. He was proceeding to inspect the position, when he was shot through the neck. "64). Met sy aankoms op Doornkraal, het It kol De Lisle hom gehaas na die "rooi huis" ...

  3. DIE SLAG VAN BLOEDRIVIER~

    African Journals Online (AJOL)

    cast iron blown over with bronze stands today. ... deur 'n moerasagtige pan effens noord van die noordel ike drif. Ook hierdeur is die laer in 'n mate gedek. Meer na die suidweste het die bree. Gelato-kop, na die Slag 'Vechtkop' genoem, oor die laer getroon. HOGOsptl'nr. 'i'OSRASACT IGE: PAN. BLOEDRIVI3R. S'S.

  4. Production and Compression Strength of Mortars Containing Unprocessed Waste Powdered Steel Slag

    Directory of Open Access Journals (Sweden)

    Stefano Maschio

    2017-12-01

    Full Text Available This paper deals with the production of mortars prepared using a commercial CEMIIB-S 42.5N cement, a natural aggregate, steelmaking slag, a superplasticizer and water. The as-received unprocessed steel slag was milled by a hammer mill and then sieved to obtain batches with different maximum particle size. Each batch was used, together with the other components, in the production of mortars which were tested, by compression and water absorption, after different aging times in order to evaluate their long term stability. Several slag-free samples were also prepared as reference materials. All mortars were prepared with fixed aggregate/cement ratio (6/1, superplasticizer/cement ratio (s/c and water/cement ratio (w/c. It has been demonstrated that an adequate protocol for the preparation and the use of slag containing particles with 2500 µm maximum size lead to the production of materials with mechanical properties suitable for civil engineering applications after aging for 28, 90 and 180 days. However, samples containing slag particles with size equal or greater than 1000 µm display a decay of mechanical properties after longer aging in water or after accelerated aging.

  5. Immobilization of radioactive waste in cement based matrices

    International Nuclear Information System (INIS)

    Glasser, F.P.; Rahman, A.A.; Macphee, S.; Atkins, M.; Beckley, N.; Carson, S.

    1986-11-01

    Experimental and theoretical studies of hydrated cement systems are described. The behaviour of slag-based cement is described with a view to predicting their long term pH, Esub(n) and mineralogical balance. Modelling studies which enable the prediction at long ages of cement composites are advanced and a base model of the CaO-SiO 2 -H 2 O system presented. The behaviour of U and I in cements is explored. The tolerance of cement systems for a wide range of miscellaneous waste stream components and environmental hazards is described. The redox potential in cements is effectively lowered by irradiation. (author)

  6. Fracture properties of concrete specimens made from alkali activated binders

    Science.gov (United States)

    Šimonová, Hana; Kucharczyková, Barbara; Topolář, Libor; Bílek, Vlastimil, Jr.; Keršner, Zbyněk

    2017-09-01

    The aim of this paper is to quantify crack initiation and other fracture properties - effective fracture toughness and specific fracture energy - of two types of concrete with an alkali activated binder. The beam specimens with a stress concentrator were tested in a three-point bending test after 28, 90, and 365 days of maturing. Records of fracture tests in the form of load versus deflection (P-d) diagrams were evaluated using effective crack model and work-of-fracture method and load versus mouth crack opening displacement (P-CMOD) diagrams were evaluated using the Double-K fracture model. The initiation of cracks during the fracture tests for all ages was also monitored by the acoustic emission method. The higher value of monitored mechanical fracture parameters of concrete with alkali activated blast furnace slag were achieved with substitution blast furnace slag by low calcium fly ash in comparison with substitution by cement kiln dust.

  7. ACCELERATED CARBONATION OF STEEL SLAG COMPACTS: DEVELOPMENT OF HIGH STRENGTH CONSTRUCTION MATERIALS

    Directory of Open Access Journals (Sweden)

    Mieke eQuaghebeur

    2015-12-01

    Full Text Available Mineral carbonation involves the capture and storage of carbon dioxide in carbonate minerals. Mineral carbonation presents opportunities for the recycling of steel slags and other alkaline residues that are currently landfilled. The Carbstone process was initially developed to transform non-hydraulic steel slags (stainless steel slag and basic oxygen furnace slags in high quality construction materials. The process makes use of accelerated mineral carbonation by treating different types of steel slags with CO2 at elevated pressure (up to 2 MPa and temperatures (20 to 140°C. For stainless steel slags raising the temperature from 20 to 140°C had a positive effect on the CO2 uptake, strength development and the environmental properties (i.e. leaching of Cr and Mo of the carbonated slag compacts. For BOF slags raising the temperature was not beneficial for the carbonation process. Elevated CO2 pressure and CO2 concentration of the feed gas had a positive effect on the CO2 uptake and strength development for both types of steel slags. In addition also the compaction force had a positive effect on the strength development. The carbonates that are produced in-situ during the carbonation reaction act as a binder, cementing the slag particles together. The carbonated compacts (Carbstones have technical properties that are equivalent to conventional concrete products. An additional advantage is that the carbonated materials sequester 100 to 150 g CO2/kg slag. The technology was developed on lab scale by optimisation of process parameters with regard to compressive strength development, CO2 uptake and environmental properties of the carbonated construction materials. The Carbstone technology was validated using (semi-industrial equipment and process conditions.

  8. Immobilization of radioactive waste in cement-based matrices

    International Nuclear Information System (INIS)

    Glasser, F.P.; Rahman, A.A.; Macphee, D.; Angus, M.J.; Atkins, M.; Dept. of Chemistry)

    1985-01-01

    A solubility model of the system CaO-SiO 2 -H 2 O is developed which takes account of the state of Si polymerization in the solid. Free energies of formations of its bonding hydrogel are tabulated. The internal redox conditions in cements have been measured; in particular, slags lower the Esub(eta) relative to OPC. The fate of Sr and U in cement systems has been determined; Sr is incorporated in the aluminate phases, while U 6+ is precipitated as Ca-U-O-H 2 O phases. Lowering the internal Esub(eta) reduces U solubility. Studies of the carbonation of slag-cement blends are reported. (author)

  9. Alkali-Activated Natural Pozzolan/Slag Binder for Sustainable Concrete

    Science.gov (United States)

    Najimi, Meysam

    This study aimed to fully replace Portland cement (PC) with environmentally friendly binders capable of improving longevity of concrete. The new binders consisted of different proportions of natural Pozzolan and slag which were alkaline-activated with various combinations of sodium hydroxide and sodium silicate. A step-by-step research program was designed to (1) develop alkali-activated natural Pozzolan/slag pastes with adequate fresh and strength properties, (2) produce alkali-activated natural Pozzolan/slag mortars to assess the effects of dominant variables on their plastic and hardened properties, and (3) finally produce and assess fresh, mechanical, dimensional, transport and durability properties of alkali-activated natural Pozzolan/slag concretes. The major variables included in this study were binder combination (natural Pozzolan/slag combinations of 70/30, 50/50 and 30/70), activator combination (sodium silicate/sodium hydroxide combinations of 20/80, 25/75 and 30/70), and sodium hydroxide concentration (1, 1.75 and 2.5M). The experimental program assessed performance of alkali-activated natural Pozzolan/slag mixtures including fresh properties (flow and setting times), unit weights (fresh, demolded and oven-dry), mechanical properties (compressive and tensile strengths, and modulus of elasticity), transport properties (absorption, rapid chloride penetration, and rapid chloride migration), durability (frost resistance, chloride induced corrosion, and resistance to sulfuric acid attack), and dimensional stability (drying shrinkage). This study also compared the performance of alkali-activated natural Pozzolan/slag concretes with that of an equivalent reference Portland cement concrete having a similar flow and strength characteristics. The results of this study revealed that it was doable to find optimum binder proportions, activator combinations and sodium hydroxide concentrations to achieve adequate plastic and hardened properties. Nearly for all studied

  10. Development and start up of a co-injection system of coal tar/natural gas in blast furnace no. 4; Desarrollo y puesta en operacion de un sistema de co-inyeccion de alquitran/gas natural en el alto horno no. 4

    Energy Technology Data Exchange (ETDEWEB)

    Falcon Rodriguez, Manuel I.; Mata Esparza, Hector Rolando; Arevalo Ballesteros, Gerardo [Altos Hornos de Mexico S. A., Coahuila (Mexico)

    1993-12-31

    The crisis has attracted the world`s attention on the need for energy conservation and the development in a greater extent the utilization of carbon base fuels and other energy sources (nuclear energy). Being a blast furnace, not only an energy consumer but also an energy producer, the greatest contribution to the pig iron cost is the energy needed to melt and reduce to metallic state the iron ores, this energy is mainly derived from coke. The dependence on coal via the coking plant to produce first fusion iron is incremented day after day as a result of the high levels of production. Altos Hornos de Mexico (AHMSA), contemplated within its strategic plan, the reduction in the production of its coking plants derived from the natural aging of its furnaces, consequently the shortage of coke for productions higher than 2.6 MMT of pig iron is pending. The injection of fuels into a blast furnace through its nozzles is a technology used for the diminishing the coke consumption of coke, its use implies a change in the philosophy of the blast furnace operation, and is currently employed in most of the blast furnaces of the world. AHMSA taking advantage of coal tar production (approx. 130 tons/day) in its coking plants decided the design and put into operation a co-injection system of coal tar and natural gas. The activities tending to carry out this project were initiated on April 1993, performing all of them with its own resources, completing them on July 18, 1993, day on which the injection of coal tar/natural gas in blast furnace No. 4 in a stable form. To date (October 1993), the coal tar injection has been increased up to 36 kg/ton of pig iron. During the injection periods, the presence of operational, mechanical and instrumentation problems have not been an obstacle for the evolution on the injection, fulfilling its function of substituting coke in a replacing relationship of 1:1, i.e. 1 kg of coal tar per each kg of coke, without affecting the product quality

  11. Synthesis of Portland cement and calcium sulfoaluminate-belite cement for sustainable development and performance

    Science.gov (United States)

    Chen, Irvin Allen

    Portland cement concrete, the most widely used manufactured material in the world, is made primarily from water, mineral aggregates, and portland cement. The production of portland cement is energy intensive, accounting for 2% of primary energy consumption and 5% of industrial energy consumption globally. Moreover, portland cement manufacturing contributes significantly to greenhouse gases and accounts for 5% of the global CO2 emissions resulting from human activity. The primary objective of this research was to explore methods of reducing the environmental impact of cement production while maintaining or improving current performance standards. Two approaches were taken, (1) incorporation of waste materials in portland cement synthesis, and (2) optimization of an alternative environmental friendly binder, calcium sulfoaluminate-belite cement. These approaches can lead to less energy consumption, less emission of CO2, and more reuse of industrial waste materials for cement manufacturing. In the portland cement part of the research, portland cement clinkers conforming to the compositional specifications in ASTM C 150 for Type I cement were successfully synthesized from reagent-grade chemicals with 0% to 40% fly ash and 0% to 60% slag incorporation (with 10% intervals), 72.5% limestone with 27.5% fly ash, and 65% limestone with 35% slag. The synthesized portland cements had similar early-age hydration behavior to commercial portland cement. However, waste materials significantly affected cement phase formation. The C3S--C2S ratio decreased with increasing amounts of waste materials incorporated. These differences could have implications on proportioning of raw materials for cement production when using waste materials. In the calcium sulfoaluminate-belite cement part of the research, three calcium sulfoaluminate-belite cement clinkers with a range of phase compositions were successfully synthesized from reagent-grade chemicals. The synthesized calcium sulfoaluminate

  12. Study on the ratio and properties of the slurry of light insulation masonry with volcanic slag

    Science.gov (United States)

    Liguang, Xiao; Dawei, Jiang

    2017-12-01

    Volcanic slag is a kind of natural high quality porous material, and it has a good thermal insulation effect, and it is an extremely rich natural resource. Therefore, this paper adopts the natural volcanic slag as the aggregate to build the insulation mortar mix design for the slag masonry, and tests the related performance of the mortar. The results show that adopts natural volcanic slag as the aggregate and the cement use fly ash to replace, and the appropriate uniform sealing pores were introduced into the mortar mix. The performance of the manufactured products can meet the requirements of JC/T890. The coefficient of thermal conductivity of lightweight masonry mortar is less than 0.14W/(m•K), and the frost resistance is greater than 100 times, and it is with a low price.

  13. Effect of the microstructure of mortars with low hydraulicity slag on their behavior in aggressive environments

    Directory of Open Access Journals (Sweden)

    Ahmed Hadj sadok

    2018-01-01

    Full Text Available Slag is one of the most used cement additives. Due to its latent hydraulic nature, attached to its hydraulicity, it can contribute to a microstructural modification and an improvement of the durability of the concrete face of aggressive environments. In this study, a low active slag is used in the manufacture of mortars as a substitute for cement, at a maximum rate of 50%. Firstly, a study of the microstructure with mercury porosimetry was used for determination of microstructural parameters (porosity, diameters and volume distribution. The behavior of mortars in aggressive environments (sodium and magnesium sulphate and seawater was studied later. Despite the low reactivity of studied slag, its presence especially at 50% rate, in the long term, has led to a refinement of the microstructure. This effect, among others, led to better resistivity of the mortars in the sulphate environnements.

  14. Receiving clincer from iron and steel production wasters

    Directory of Open Access Journals (Sweden)

    Володимир Петрович Кравченко

    2017-06-01

    Full Text Available By means of burning at different temperature conditions of a two-component raw mix consisting of iron and steel production wastes: blast-furnace slags wastes - limestone wastes ratio of 2:3, correspondingly, clinker samples were obtained, chemical analysis of which showed correspondence of their chemical composition to the chemical composition of the standard clinker. Laboratory testing proved high strength values for all the clinker samples. Processing of metallurgical wastes that are accumulated in the dumps in large quantities and have harmful effects on the environment, is relevant now, especially for low-cost PC (Portland cement clinker production, the production of which by existing technologies is expensive and energy consuming, accompanied by a significant consumption of natural resources and energy, harmful emissions of dust and gas in the atmosphere. The aim is to develop the technological scheme of PC clinker production. The hydraulic module (m = 2,37 of 2-component mixtures of raw materials: 40% of slag waste + 60% of limestone waste has been defined. Mechanical activation of cement components has been found to promote the blast furnace slags activity. It has been stated that slags should be subjected to fine grinding(S ≥ 0,6 m2/g while PC clinker should be subjected to fine crushing (S = 0,3 m2/g. Jet grinding can reduce 4-5 times the content of expensive clinker in cement, and reduce 4-5 times СО2 emissions. The process for producing clinker from metallurgical wastes and cement production from blast furnace slag are protected by patents of Ukraine

  15. Recycling of red muds with the extraction of metals and special additions to cement

    Science.gov (United States)

    Zinoveev, D. V.; Diubanov, V. G.; Shutova, A. V.; Ziniaeva, M. V.

    2015-01-01

    The liquid-phase reduction of iron oxides from red mud is experimentally studied. It is shown that, in addition to a metal, a slag suitable for utilization in the construction industry can be produced as a result of pyrometallurgical processing of red mud. Portland cement is shown to be produced from this slag with mineral additions and a high-aluminate expansion addition to cement.

  16. Low CO{sub 2} emission technologies for iron and steelmaking as well as titania slag production

    Energy Technology Data Exchange (ETDEWEB)

    Orth, A.; Anastasijevic, N.; Eichberger, H. [Outokumpu Technol GmbH, Oberursel (Germany)

    2007-08-15

    Outokumpu Technology has developed direct reduction technologies that allow in combination with smelting reduction processes or electric arc furnaces a substantial lowering of CO{sub 2} emissions. In this paper three examples are given: The Circofer process, already demonstrated in pilot plant scale, uses coal as reductant in a two stage CFB (circulating fluidized bed)/FB (fluidized bed) reactor configuration to obtain a highly metallized product suitable for charging into smelting processes. One possible application of Circofer is, in a single stage configuration, as prereduction unit in combination with HIsmelt a smelting reduction technology to produce hot metal using iron ore and coal fines. Using Circofer as prereduction step, the capacity of a given HIsmelt installation can be increased by the factor three to four compared to cold feed and CO, emission can be lowered to values about 20% below the standard of a modern blast furnace, as this combination of technologies requires no agglomeration plant or coke ovens. A second application of Circofer is the combination with an electric arc furnace (EAF) to produce steel directly from direct reduced iron (DRI). Charging hot DRI into an EAF decreases drastically electric power consumption and thus further lowers CO, emission. Applying Circosmelt, the combination of a single stage Circofer system with an electric reduction furnace for ilmenite processing, only half of the electric power consumption required today for titania slag production using cold, unreduced feed material is required. A common additional advantage of all Circofer based routes is that a 99% pure CO{sub 2} stream is removed for process reasons from the process gas and can be used for enhanced crude oil production or sequestration methods.

  17. Study of effect of electric arc furnace slag on expansion of mortars subjected to alkali-aggregate reaction

    Directory of Open Access Journals (Sweden)

    L. SOUZA

    Full Text Available Abstract Alkali-aggregate reaction is a chemical reaction between cement alkalis and some reactive mineral present in some aggregates, leading to concrete expansion and cracking. One kind usually observed and studied in Brazil is the alkali-silica reaction, due to its fast development. There are several methods that are effective to control and mitigate this reaction, and one of them is the partial replacement of cement by mineral additions such as pozzolans like fly-ash, silica fume and slag. In this study, we propose the use of electrical steel slag as a partial replacement of cement, evaluating its effectiveness by NBR 15577:2008, employing different proportions as replacement. It seems that the electrical steel slag, despite its expansive behavior, has been effective in the control of the ASR.

  18. Sadhana | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    The effect of blast furnace slag on the self-compactability of pumice aggregate lightweight concrete · Murat Kurt Türkay Kotan Muhammed Said Gül Rüstem Gül Abdulkadir Cüneyt Aydin · More Details Abstract Fulltext PDF. This paper presents the results of an experimental study of the effects of blast furnace slag, different ...

  19. Steel desulphurization with synthetic slag

    Energy Technology Data Exchange (ETDEWEB)

    Heput, T.; Ardelean, E.; Socalici, A.; Maksay, S.; Gavanescu, A.

    2007-07-01

    Generally speaking, sulfur is considered a harmful element for steel quality, reason why all the technological steps are being taken in order to eliminate it from the metal bath. This paper deals with the influence of the chemical composition, on the slag quantity and of the batch stirring condition upon the desulfurization process in the casting ladle by treatment with synthetic slag. The experiments were made at an open-hearth plant with the steel tapping in two ladles (the desulfurization was made with synthetic slag at one ladle while the other one was considered standard) and at the electric steel plant and for the synthetic slag formation a mix was used, made, according to several receipts, of : lime (50-75%), fluorine (0-17%); bauxite (0-32%) and aluminous slag (8-22%). The data were processed in the calculation programs EXCEL and MATLAB, which resulted in a series of correlations between the desulfurization degree and the chemical composition of the slag, respectively the slag quantity both for the charges bubbled with Argon and the un bubbled ones. (Author) 5 refs.

  20. Pore structure in blended cement pastes

    DEFF Research Database (Denmark)

    Canut, Mariana Moreira Cavalcanti

    Supplementary cementitious materials (SCMs), such as slag and fly ash, are increasingly used as a substitute for Portland cement in the interests of improvement of engineering properties and sustainability of concrete. According to studies improvement of engineering properties can be explained...... supplement each other. Cement pastes (w/b=0.4) with and without slag and fly ash cured at two moisture (sealed and saturated) and temperature (20 and 55ºC) conditions were used to investigate the combined impact of SCMs addition and curing on the pore structure of pastes cured up to two years. Also...... volume and threshold pore size were found when comparing with plain cement paste at the same curing conditions. The porosity methods MIP, LTC and SEM have been shown to be suitable to characterise pore parameters of the pastes. MIP is a simple and fast method which covers a large range of pore sizes...

  1. The Effects of Substitution of The Natural Sand by Steel Slag in The Properties of Eco-Friendly Concrete with The 1:2:3 Ratio Mixing Method

    Science.gov (United States)

    Rahmawati, A.; Saputro, I. N.

    2018-03-01

    This study was motivated by the need for the development of eco-friendly concrete, and the use of large quantities of steel slag as an industrial waste which is generated from the steel manufacturers. This eco-friendly concrete was developed with steel slag as a substitute for natural sand. Properties of concrete which used waste slag as the fine aggregate with the 1 cement: 2 sand : 3 coarse aggregate ratio mixing method were examined. That ratio was in volume. Then a part of natural sand replaced with steel slag sand in six variations percentages that were 0 %, 20 %, 40 %, 60 %, 80 % and 100 %. The compressive strength, tensile strength, and flexural strength of concrete specimens were determined after curing for 28 days. The research results demonstrate that waste steel slag can increase the performance of concrete. The optimal percentage substitution natural sand by steel slag sand reached of slag on the percentage of 20 % which reached strength ratios of steel slag concrete to the strength of conventional concrete with natural sandstone were 1.37 for compressive strength and 1.13 for flexural strength. While the tensile strength reached a higher ratio of concrete with steel slag sand to the concrete with natural sand on the 80% substitution of natural sand with steel slag sand.

  2. Slag Behavior in Gasifiers. Part II: Constitutive Modeling of Slag

    Directory of Open Access Journals (Sweden)

    Mehrdad Massoudi

    2013-02-01

    Full Text Available The viscosity of slag and the thermal conductivity of ash deposits are among two of the most important constitutive parameters that need to be studied. The accurate formulation or representations of the (transport properties of coal present a special challenge of modeling efforts in computational fluid dynamics applications. Studies have indicated that slag viscosity must be within a certain range of temperatures for tapping and the membrane wall to be accessible, for example, between 1,300 °C and 1,500 °C, the viscosity is approximately 25 Pa·s. As the operating temperature decreases, the slag cools and solid crystals begin to form. Since slag behaves as a non-linear fluid, we discuss the constitutive modeling of slag and the important parameters that must be studied. We propose a new constitutive model, where the stress tensor not only has a yield stress part, but it also has a viscous part with a shear rate dependency of the viscosity, along with temperature and concentration dependency, while allowing for the possibility of the normal stress effects. In Part I, we reviewed, identify and discuss the key coal ash properties and the operating conditions impacting slag behavior.

  3. Slag Behavior in Gasifiers. Part II: Constitutive Modeling of Slag

    Energy Technology Data Exchange (ETDEWEB)

    Massoudi, Mehrdad [National Energy Technology Laboratory; Wang, Ping

    2013-02-07

    The viscosity of slag and the thermal conductivity of ash deposits are among two of the most important constitutive parameters that need to be studied. The accurate formulation or representations of the (transport) properties of coal present a special challenge of modeling efforts in computational fluid dynamics applications. Studies have indicated that slag viscosity must be within a certain range of temperatures for tapping and the membrane wall to be accessible, for example, between 1,300 °C and 1,500 °C, the viscosity is approximately 25 Pa·s. As the operating temperature decreases, the slag cools and solid crystals begin to form. Since slag behaves as a non-linear fluid, we discuss the constitutive modeling of slag and the important parameters that must be studied. We propose a new constitutive model, where the stress tensor not only has a yield stress part, but it also has a viscous part with a shear rate dependency of the viscosity, along with temperature and concentration dependency, while allowing for the possibility of the normal stress effects. In Part I, we reviewed, identify and discuss the key coal ash properties and the operating conditions impacting slag behavior.

  4. Modified sulphur cement: A low porosity encapsulation material for low, medium and alpha waste

    International Nuclear Information System (INIS)

    Dalen, A. van; Rijpkema, J.E.

    1989-01-01

    Modified sulphur cement, available under the trade name Chement 2000, is a thermoplastic candidate material for the matrix of low, intermediate and alpha radioactive waste. The main source of sulphur is the desulphurization of fossil fuels. In view of the future increase of this product a modified compound of sulphur has been developed at the US Bureau of Mines. Modified sulphur cement as matrix material has properties in common with Portland or blast furnace cement and bitumen. The mechanical strength is comparable to hydraulic cement products. The process to incorporate waste materials is identical to bitumization. The leachability and the resistance to attack by chemicals is nearly the same as for bituminized products. This study showed also that the radiation resistance is high without radiolytic gas production and without change in dimensions (swelling). The rigidity of the matrix is a disadvantage when internal pressures are built up. The thermal conductivity and the heat of combustion of sulphur is low resulting in slow damage to the waste form under fire conditions, even when the temperature of self ignition in air is 220 0 C. The low leachability, the very slow effective diffusion of H 2 O and HTO, and the low permeability is due to the small pore diameters in the modified sulphur matrix. The loading capacity of modified sulphur cement depends on grain size and distribution and is for ungraded ashes, precipitates, dried sludges, etc., in the order of 40-50% of weight. The price of Chement 2000 per tonne is equal to those of blown bitumen

  5. Experimental investigation of surface modified EOF steel slag as coarse aggregate in concrete

    Directory of Open Access Journals (Sweden)

    Y.K. Sabapathy

    2017-10-01

    Full Text Available An experimental work was carried out to study the effect of Energy Optimizing Furnace (EOF steel slag as coarse aggregate replacement in concrete. Surface modification of slag was carried out to seal the surface voids of raw slag aggregates. Quarry dust obtained as an extractive waste from the granite stone quarries has been used as a blending material in this work. After several trials, it was found that a mix proportion of 1:6:14 (cement:quarry dust:slag aggregate was the most suitable mix ratio for the surface modification of the slag aggregates. Various mixes of concrete were prepared with different proportions of modified slag (ranging from 0% to 100% as replacements for aggregates. Three grades of concrete (20 MPa, 30 MPa and 40 MPa were used in the investigation and the concrete mixes were evaluated for compressive strength and splitting tensile strength. It was found that the compressive strength improved for 25 percent replacement of natural coarse aggregates. The splitting tensile strength was found to peak at 25 percent replacement of natural aggregates.

  6. Effect of SCM on porosity

    DEFF Research Database (Denmark)

    Canut, Mariana

    and connectivity of pores affect durability. Supplementary cementitious materials (SCMs) are being increasingly used as a substitute for Portland cement in the interests of sustainability and to improve the engineering properties of concrete as strength and durability. SCMs are by-products such as slag from iron...... blast furnaces, fly ash from coal fired power stations, and silica fume from ferrosilicon production. Studies suggest that the improvement of the strength and durability using SCMs are governed by refinement of the pores in the cement paste. Both the chemical and physical properties of the SCMs...

  7. Effect of extra-fine slag replacement on carbonation and frost salt scaling resistance of mortars[ACI SP-234-8

    Energy Technology Data Exchange (ETDEWEB)

    Copuroglu, O.; Fraaij, A.; Schlangen, E. [Delft Univ. of Technology, Delft (Netherlands). Dept. of Civil Engineering; Bijen, J. [INTRON (Netherlands)

    2006-07-01

    This study examined the effects of extra-fine slag (EFS) on the carbonation and frost salt scaling resistance of mortars at different replacement levels for 2 types of cements. In the first part of the examination, EFS replaced a certain amount of European CEM 3/B cement composed of 67 per cent slag with ordinary fineness. The second part examined the effect of EFS on microstructure and frost salt scaling resistance of mortars at different replacement levels in European normal portland cement CEM 1 32,5R. The average Blaine fineness of EFS was 500 m{sup 2}/kg. The water to cement ratio was maintained at 0.45. The carbonation resistance and pore structure of the cement mortars was examined. Carbonation resistance was measured using the phenolphthalein method after accelerated carbonation tests in a 3 per cent carbon dioxide chamber. Mercury intrusion porosimetry was used to study the pore structures. The chemical and physical properties of this cement were presented along with the obtained cement blends. The first part of the study showed that increasing the average fineness and total amount of slag results in a higher degrees of water uptake compared to the control sample. Therefore, it was claimed that the critical amount of normal portland cement clinker is important in terms of carbonation and frost salt scaling durability. It was concluded that an increasing EFS content lowers the scaling resistance. The effect is most evident when the replacement percentage is increased from 50 to 75 per cent. It was suggested that future studies should focus on the content of normal portland cement clinker, the hydration rate of clinker and slag, as well as the related activation of the slag. 10 refs., 5 tabs., 12 figs.

  8. THE INFLUENCE OF PHOSPHORUS SLAG ADDITION ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF METAKAOLIN-BASED GEOPOLYMER PASTES

    Directory of Open Access Journals (Sweden)

    M. A. SOLEIMANI

    2013-03-01

    Full Text Available In this study, metakaolin plus different weight percent of phosphorus slag (10-100 wt. % were used in preparation of geopolymer. The compressive strength, phase analysis and microstructure changes were compared with a metakaolin based geopolymer control sample. Results showed that the substitution of slag up to 40 wt. % instead of metakaolin increase the 28 days compressive strength (14.5 % compared with control sample. This enhancement of strength is related to coexistence of geopolymeric gel and C‒S‒H gel or C‒A‒S‒H phase by XRD and FTIR study. In slag containing geopolymer samples some microcracks were observed at microstructure that established by volume change during formation of new phase or mismatching of unreacted particle with geopolymeric gel. These microcrack can dominate at high content of slag (above 40 wt. % substitution and decrease the strength of samples. These results show that it is possible to produce geopolymer cement from waste phosphorus slages.

  9. Thermally conductive cementitious grout for geothermal heat pump systems

    Science.gov (United States)

    Allan, Marita

    2001-01-01

    A thermally conductive cement-sand grout for use with a geothermal heat pump system. The cement sand grout contains cement, silica sand, a superplasticizer, water and optionally bentonite. The present invention also includes a method of filling boreholes used for geothermal heat pump systems with the thermally conductive cement-sand grout. The cement-sand grout has improved thermal conductivity over neat cement and bentonite grouts, which allows shallower bore holes to be used to provide an equivalent heat transfer capacity. In addition, the cement-sand grouts of the present invention also provide improved bond strengths and decreased permeabilities. The cement-sand grouts can also contain blast furnace slag, fly ash, a thermoplastic air entraining agent, latex, a shrinkage reducing admixture, calcium oxide and combinations thereof.

  10. COAL SLAGGING AND REACTIVITY TESTING

    Energy Technology Data Exchange (ETDEWEB)

    Donald P. McCollor; Kurt E. Eylands; Jason D. Laumb

    2003-10-01

    Union Fenosa's La Robla I Power Station is a 270-MW Foster Wheeler arch-fired system. The unit is located at the mine that provides a portion of the semianthracitic coal. The remaining coals used are from South Africa, Russia, Australia, and China. The challenges at the La Robla I Station stem from the various fuels used, the characteristics of which differ from the design coal. The University of North Dakota Energy & Environmental Research Center (EERC) and the Lehigh University Energy Research Center (LUERC) undertook a program to assess problematic slagging and unburned carbon issues occurring at the plant. Full-scale combustion tests were performed under baseline conditions, with elevated oxygen level and with redistribution of air during a site visit at the plant. During these tests, operating information, observations and temperature measurements, and coal, slag deposit, and fly ash samples were obtained to assess slagging and unburned carbon. The slagging in almost all cases appeared due to elevated temperatures rather than fuel chemistry. The most severe slagging occurred when the temperature at the sampling port was in excess of 1500 C, with problematic slagging where first-observed temperatures exceeded 1350 C. The presence of anorthite crystals in the bulk of the deposits analyzed indicates that the temperatures were in excess of 1350 C, consistent with temperature measurements during the sampling period. Elevated temperatures and ''hot spots'' are probably the result of poor mill performance, and a poor distribution of the coal from the mills to the specific burners causes elevated temperatures in the regions where the slag samples were extracted. A contributing cause appeared to be poor combustion air mixing and heating, resulting in oxygen stratification and increased temperatures in certain areas. Air preheater plugging was observed and reduces the temperature of the air in the windbox, which leads to poor combustion

  11. Exploring the life cycle management of industrial solid waste in the case of copper slag.

    Science.gov (United States)

    Song, Xiaolong; Yang, Jianxin; Lu, Bin; Li, Bo

    2013-06-01

    Industrial solid waste has potential impacts on soil, water and air quality, as well as human health, during its whole life stages. A framework for the life cycle management of industrial solid waste, which integrates the source reduction process, is presented and applied to copper slag management. Three management scenarios of copper slag are developed: (i) production of cement after electric furnace treatment, (ii) production of cement after flotation, and (iii) source reduction before the recycling process. A life cycle assessment is carried out to estimate the environmental burdens of these three scenarios. Life cycle assessment results showed that the environmental burdens of the three scenarios are 2710.09, 2061.19 and 2145.02 Pt respectively. In consideration of the closed-loop recycling process, the environmental performance of the flotation approach excelled that of the electric furnace approach. Additionally, although flash smelting promotes the source reduction of copper slag compared with bath smelting, it did not reduce the overall environmental burdens resulting from the complete copper slag management process. Moreover, it led to the shifting of environmental burdens from ecosystem quality damage and resources depletion to human health damage. The case study shows that it is necessary to integrate the generation process into the whole life cycle of industrial solid waste, and to make an integrated assessment for quantifying the contribution of source reduction, rather than to simply follow the priority of source reduction and the hierarchy of waste management.

  12. An Experimental Study On Carbonation Of Plain And Blended Cement Concrete

    Directory of Open Access Journals (Sweden)

    Yunusa Alhassan

    2017-08-01

    Full Text Available This paper presents a laboratory investigation on the early age properties and carbonation of concrete containing Ground Granulated Blast Furnace GGBS in an inland environment. Properties of concrete made with GGBS blended cement was characterized in terms of physical and chemical composition at early-age. In addition the effects of inland exposure condition on the durability performance of companion concrete were also investigated in the medium term. Concrete cubes were made using various concrete mixtures of water-binder ratios wb 0.40 0.50 0.60 0.75 and binder contents 300 350 400 450 kgm3. Concrete cube of 100 mm size were cast and cured in water for 3 7 or 28 days then characterized at early-ages in terms of its physical and chemical properties. Companion concrete samples were exposed indoor or outdoors to undergo carbonation under natural environment. At the end of the varying exposure period 6 12 18 and 24 months the concrete cube samples were characterized in terms of carbonation depths. The results of the concrete early-age properties and medium-term durability characterisation were analyzed. The results show that increased knowledge of concrete materials concrete early-age properties and its exposure conditions are vital in durability considerations for RC structures.

  13. Construction material properties of slag from the high temperature arc gasification of municipal solid waste.

    Science.gov (United States)

    Roessler, Justin G; Olivera, Fernando D; Wasman, Scott J; Townsend, Timothy G; McVay, Michael C; Ferraro, Christopher C; Blaisi, Nawaf I

    2016-06-01

    Slag from the high temperature arc gasification (HTAG) of municipal solid waste (MSW) was tested to evaluate its material properties with respect to use as a construction aggregate. These data were compared to previously compiled values for waste to energy bottom ash, the most commonly produced and beneficially used thermal treatment residue. The slag was tested using gradations representative of a base course and a course aggregate. Los Angeles (LA) abrasion testing demonstrated that the HTAG slag had a high resistance to fracture with a measured LA loss of 24%. Soundness testing indicated a low potential for reactivity and good weathering resistance with a mean soundness loss of 3.14%. The modified Proctor compaction testing found the slag to possess a maximum dry density (24.04kN/m(3)) greater than conventionally used aggregates and WTE BA. The LBR tests demonstrated a substantial bearing capacity (>200). Mineralogical analysis of the HTAG suggested the potential for self cementing character which supports the elevated LBR results. Preliminary material characterization of the HTAG slag establishes potential for beneficial use; larger and longer term studies focusing on the material's possibility for swelling and performance at the field scale level are needed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Combined Performance of Polypropylene Fibre and Weld Slag in High Performance Concrete

    Science.gov (United States)

    Ananthi, A.; Karthikeyan, J.

    2017-12-01

    The effect of polypropylene fibre and weld slag on the mechanical properties of High Performance Concrete (HPC) containing silica fume as the mineral admixtures was experimentally verified in this study. Sixteen series of HPC mixtures(70 MPa) were designed with varying fibre fractions and Weld Slag (WS). Fibre added at different proportion (0, 0.1, 0.3 and 0.6%) to the weight of cement. Weld slag was substituted to the fine aggregate (0, 10, 20 and 30%) at volume. The addition of fibre decreases the slump at 5, 9 and 14%, whereas the substitution of weld slag decreases by about 3, 11 and 21% with respect to the control mixture. Mechanical properties like compressive strength, split tensile strength, flexural strength, Ultrasonic Pulse Velocity test (UPV) and bond strength were tested. Durability studies such as Water absorption and Sorptivity test were conducted to check the absorption of water in HPC. Weld slag of 10% and fibre dosage of 0.3% in HPC, attains the maximum strength and hence this combination is most favourable for the structural applications.

  15. セメント種類の違いがセメント安定処理土の一軸圧縮特性に及ぼす影響

    OpenAIRE

    亀井, 健史; 大本, 和樹; 松尾, 和俊

    2003-01-01

    This paper describes the effects of cement type on unconfined compressive characteristics of cement-stabilized soils. Two cements were used in the present study the normal portland cement and the portland blast-furnace(B) cement. Results of unconfined compression tests on stabilized soils show that the differences in unconfined compressive characteristics between cement stabilized soil utilizing normal portland cement and portland blast-furnace(B) cement tested at the same compound conditions...

  16. Design of Slag Thickness Fuzzy Control System for Slag Adding Robot

    Directory of Open Access Journals (Sweden)

    Guo Yuan

    2017-01-01

    Full Text Available According to the defect of artificial slag adding and open-loop slag adding in continuous casting mold, a slag adding robot with real-time slag thickness detection and feedback control is developed. That is, the laser ranging sensor is applied on the basis of the open-loop slag adding robot. Then the real-time information of in-mold slag thickness can be obtained. And the coupling relation of three factors: real-time slag thickness, mold work slagging speed and robot slagging rate are taken into comprehensive consideration. Therefore fuzzy controller is built to realize the fuzzy PID control of the slagging robot feeding electro-mechanical system and achieve the intelligent control of slag thickness in the mold. The simulation and application results show that the slag adding robot based on fuzzy PID control has good effect and quick response. The slag can be pressed according to the requirement, which is beneficial to energy saving and consumption reduction, and improves the quality of the billet.

  17. Cement Formation

    DEFF Research Database (Denmark)

    Telschow, Samira; Jappe Frandsen, Flemming; Theisen, Kirsten

    2012-01-01

    Cement production has been subject to several technological changes, each of which requires detailed knowledge about the high multiplicity of processes, especially the high temperature process involved in the rotary kiln. This article gives an introduction to the topic of cement, including...... an overview of cement production, selected cement properties, and clinker phase relations. An extended summary of laboratory-scale investigations on clinkerization reactions, the most important reactions in cement production, is provided. Clinker formations by solid state reactions, solid−liquid and liquid...

  18. CO2Mineralization and Utilization using Steel Slag for Establishing a Waste-to-Resource Supply Chain.

    Science.gov (United States)

    Pan, Shu-Yuan; Chung, Tai-Chun; Ho, Chang-Ching; Hou, Chin-Jen; Chen, Yi-Hung; Chiang, Pen-Chi

    2017-12-08

    Both steelmaking via an electric arc furnace and manufacturing of portland cement are energy-intensive and resource-exploiting processes, with great amounts of carbon dioxide (CO 2 ) emission and alkaline solid waste generation. In fact, most CO 2 capture and storage technologies are currently too expensive to be widely applied in industries. Moreover, proper stabilization prior to utilization of electric arc furnace slag are still challenging due to its high alkalinity, heavy metal leaching potentials and volume instability. Here we deploy an integrated approach to mineralizing flue gas CO 2 using electric arc furnace slag while utilizing the reacted product as supplementary cementitious materials to establish a waste-to-resource supply chain toward a circular economy. We found that the flue gas CO 2 was rapidly mineralized into calcite precipitates using electric arc furnace slag. The carbonated slag can be successfully utilized as green construction materials in blended cement mortar. By this modulus, the global CO 2 reduction potential using iron and steel slags was estimated to be ~138 million tons per year.

  19. Effet du laitier de haut fourneau sur les propriétés d'ingénierie des briques de terre comprimée à base d'un sol portant de sulfate

    OpenAIRE

    Izemmouren, Ouarda; Guettala, Abdelhamid

    2014-01-01

    National audience; The soil contained a high percentage of sulfur trioxide SO3 which reacts with other minerals in the soil to form sulfates. The use of ground granulated blast furnace slag (GGBS), an industrial by-product, is a mineral additive That Gives better stabilization of soils contained a sulfate. The objective of this study is to analyze the effect of addition of (GGBS) activated by cement on compressed earth bricks (CEB) based on a sulphate bearing soil for improve its mechanical p...

  20. Decontamination solution development studies

    International Nuclear Information System (INIS)

    Allen, R.P.; Fetrow, L.K.; Kjarmo, H.E.; Pool, K.H.

    1993-09-01

    This study was conducted for the Westinghouse Hanford Company (WHC) by Pacific Northwest Laboratory (PNL) as part of the Hanford Grout Technology Program (HGTP). The objective of this study was to identify decontamination solutions capable of removing radioactive contaminants and grout from the Grout Treatment Facility (GTF) process equipment and to determine the impact of these solutions on equipment components and disposal options. The reference grout used in this study was prepared with simulated double-shell slurry feed (DSSF) and a dry blend consisting of 40 wt % limestone flour, 28 wt % blast furnace slag, 28 wt % fly ash, and 4 wt % type I/II Portland cement

  1. STRENGTH SHRINKAGE AND CREEP OF CONCRETE IN TENSION AND COMPRESSION

    Directory of Open Access Journals (Sweden)

    S A Kristiawan

    2006-01-01

    Full Text Available Strength, shrinkage and creep of concrete in tension and compression have been determined and the relationship between those properties was studied. Direct tensile tests were applied to measure those properties in tension. The relationship of creep in tension and compression was determined based on the measurement of creep at similar stress and similar stress/strength ratio. It is found that concrete deforms more in tension than in compression. Except for concrete with a higher water/cement ratio, the use of pulverised fuel ash, ground granulated blast furnace slag, superplasticizer and shrinkage reducing admixture has no effect on strength. However, they affect creep and shrinkage of concrete.

  2. Thin, applied surfacing for improving skid resistance of concrete pavements

    Science.gov (United States)

    Scholer, C. F.

    1980-12-01

    The use of select aggregate in a thin wearing surface of portland cement mortar to prolone or restore a concrete pavement's ability to develop high friction was accomplished. Two fine aggregates, blast furnace slag and lightweight expanded shale were found to exhibit skid resistance greater than the other aggregates evaluated. The British polishing wheel was used in the laboratory evaluation of aggregate to simulate wear. The need for a method of restoring friction to a worn, but otherwise sound concrete pavement led to a field evaluation of several different techniques for placing a very thin overlay. The successful method was a broomed, very thin layer of mortar, 3 mm thick.

  3. The effects of radiation on intermediate-level wasteforms: final report

    International Nuclear Information System (INIS)

    Wilding, C.R.; Phillips, D.C.; Lyon, C.E.; Burnay, S.G.; Winter, J.A.; Spindler, W.E.

    1990-10-01

    This report summarizes the results of a programme carried out on the evaluation of the effects of radiation on organic ion exchangers in cement, mixed ion exchangers in modified vinyl ester polymer, immobilised fuel hull residues in cement, incinerator ash in cement and combustible PCM in cement. Both β/γ and α irradiation experiments were carried out over a range of dose rates. Cracking and spallation can occur over a wide range of water/cement ratios at a high dose rate of 3.0 Gy s -1 for grouts based on blast furnace slag compositions. Gas pressurisation is the most likely mechanism for the damage. Cement pore water extracted from irradiated samples of combustible PCM had a pH of 9.8 after 9.0 MGy compared to 13.0 for unirradiated controls. (author)

  4. Effect of calcium/silicon ratio on retention of uranium (VI) in portland cement materials

    International Nuclear Information System (INIS)

    Tan Hongbin; Li Yuxiang

    2005-01-01

    Calcium silicate hydrate (CSH) materials of varied calcium to silicon (Ca/Si) ratios were prepared by hydrothermal synthesis at 80 degree C, with calcium oxide and micro-silicon employed. These products were determined to be of gel phase by XRD. Leaching tests with 1% hydrochloric acid indicated that more Uranium (VI) was detained by CSH with lower Ca/Si ratios. Alkali-activated slag cement (with a lower Ca/Si ratio) was found to have a stronger retention capacity than Portland cement (with a higher Ca/Si ratio), at 25 degree C in 102-days leaching tests with simulated solidified forms containing Uranium (VI). The accumulative leaching fraction of Uranium (VI) for Alkali-activated slag cement solidified forms is 17.6% lower than that for Portland cement. The corresponding difference of diffusion coefficients is 40.6%. This could be correlated with the difference of Ca/Si ratios between cements of two kinds. (authors)

  5. Steel desulphurization with synthetic slag

    Directory of Open Access Journals (Sweden)

    Heput, T.

    2007-02-01

    Full Text Available Generally speaking, sulphur is considered a harmful element for steel quality, reason why all the technological steps are being taken in order to eliminate it from the metal bath. This paper deals with the influence of the chemical composition, on the slag quantity and of the bath stirring condition upon the desulphurization process in the casting ladle by treatment with synthetic slag. The experiments were made at an open-hearth plant with the steel tapping in two ladles (the desulphurization was made with synthetic slag at one ladle while the other one was considered standard and at the electric steel plant and for the synthetic slag formation a mix was used, made, according to several receipts, of: lime (50-75%, fluorine (0-17%, bauxite (0-32% and aluminous slag (8-22%. The data were processed in the calculation programs EXCEL and MATLAB, which resulted in a series of correlations between the desulphurization degree and the chemical composition of the slag, respectively the slag quantity both for the charges bubbled with Argon and the unbubbled ones.

    En general, el azufre es considerado un elemento nocivo para la calidad del acero y, por eso, en la práctica, se toman todas las medidas de orden tecnológico para su eliminación del baño metálico. En este trabajo se analiza la influencia de la composición química, de la cantidad de escoria y del estado de agitación del baño sobre el proceso de desulfuración en la cuchara para fundir por tratamiento con escoria sintética. Los experimentos se han realizado en una acería evacuando el acero en dos ollas (en una cuchara se efectuó la desulfuración con escoria sintética y a la otra se consideró como patrón y en un acería eléctrica y para la formación de la escoria sintética se utilizó una mezcla producida según muchas recetas, formada por: cal (50-75%, fluorina (0-17%, bauxita (0-32% y escoria aluminosa (8-22%. Los datos han sido procesados en los programas de c

  6. Steel slag: a waste industrial by-product as an alternative sustainable green building material in construction applications--an attempt for solid waste management.

    Science.gov (United States)

    Pofale, Arun D; Nadeem, Mohammed

    2012-01-01

    This investigation explores the possibility of utilizing granular slag as an alternative to fine aggregate (natural sand) in construction applications like masonry and plastering. Construction industry utilizes large volume of fine aggregate in all the applications which has resulted into shortage of good quality naturally available fine aggregate. Use of granular slag serves two fold purposes, i.e. waste utilisation as well as alternative eco-friendly green building material for construction. The investigation highlights comparative study of properties with partial and full replacement of fine aggregate (natural sand) by granular slag in cement mortar applications (masonry and plastering). For this purpose, cement mortar mix proportions from 1:3, 1:4, 1:5 & 1:6 by volume were selected for 0, 25, 50, 75 & 100% replacement levels with w/c ratios of 0.60, 0.65, 0.70 & 0.72 respectively. Based on the study results, it could be inferred that replacement of natural sand with granular slag from 25 to 75% increased the packing density of mortar which resulted into reduced w/c ratio, increased strength properties of all mortar mixes. Hence, it could be recommended that the granular slag could be effectively utilized as fine aggregate in masonry and plastering applications in place of conventional cement mortar mixes using natural sand.

  7. Density increase of polyethylene solidified wastes increase by copper slag

    International Nuclear Information System (INIS)

    Tozawa, Seiichi; Dojiri, Shigeru; Moriyama, Noboru.

    1981-01-01

    A polyethylene solidification process of the low- and intermediate-level radioactive wastes generated from nuclear power facilities has already been developed. However, the density of polyethylene solidified filtersludge and spent ion-exchange resin is less than the value of 1.2, which is considered to be necessary for a waste solid to be dumped into sea. This lack of the density may cause these polyethylene solidified wastes to float on the sea surface and carry the radioactivity to the human environment, when the sealed waste containers happen to be damaged for some reasons. In this study, a trial is made to prepare polyethylene products having the higher density, and the products was adjusted to have the density of higher values than 1.2 by mixing about 32 -- 33 w/o of copper slag. These polyethylene products showed the monoaxial compressive strength of above 150 kg/cm 2 and the good stability in deionized water for immersion period of 500 days. The volume reduction factor of these heavier polyethylene products to which copper slag was added also becomes smaller, but it shows still twice as large as that of the cement- and asphalt-solidified wastes. (author)

  8. Glassy slags for minimum additive waste stabilization

    International Nuclear Information System (INIS)

    Feng, X.; Wronkiewicz, D.J.; Bates, J.K.; Brown, N.R.; Buck, E.C.; Dietz, N.L.; Gong, M.; Emery, J.W.

    1994-05-01

    Glassy slag waste forms are being developed to complement glass waste forms in implementing Minimum Additive Waste Stabilization (MAWS) for supporting DOE's environmental restoration efforts. The glassy slag waste form is composed of various crystalline and metal oxide phases embedded in a silicate glass phase. The MAWS approach was adopted by blending multiple waste streams to achieve up to 100% waste loadings. The crystalline phases, such as spinels, are very durable and contain hazardous and radioactive elements in their lattice structures. These crystalline phases may account for up to 80% of the total volume of slags having over 80% metal loading. The structural bond strength model was used to quantify the correlation between glassy slag composition and chemical durability so that optimized slag compositions were obtained with limited crucible melting and testing. Slag compositions developed through crucible melts were also successfully generated in a pilot-scale Retech plasma centrifugal furnace at Ukiah, California. Utilization of glassy slag waste forms allows the MAWS approach to be applied to a much wider range of waste streams than glass waste forms. The initial work at ANL has indicated that glassy slags are good final waste forms because of (1) their high chemical durability; (2) their ability to incorporate large amounts of metal oxides; (3) their ability to incorporate waste streams having low contents of flux components; (4) their less stringent requirements on processing parameters, compared to glass waste forms; and (5) their low requirements for purchased additives, which means greater waste volume reduction and treatment cost savings

  9. The suitability of a supersulfated cement for nuclear waste immobilisation

    Energy Technology Data Exchange (ETDEWEB)

    Collier, N.C., E-mail: nick.collier@sheffield.ac.uk [Immobilisation Science Laboratory, Department of Materials Science and Engineering, The University of Sheffield, Mappin Street, Sheffield S1 3JD (United Kingdom); Milestone, N.B. [Immobilisation Science Laboratory, Department of Materials Science and Engineering, The University of Sheffield, Mappin Street, Sheffield S1 3JD (United Kingdom); Callaghan Innovation, 69 Gracefield Road, PO Box 31310, Lower Hutt 5040 (New Zealand); Gordon, L.E. [Immobilisation Science Laboratory, Department of Materials Science and Engineering, The University of Sheffield, Mappin Street, Sheffield S1 3JD (United Kingdom); Geopolymer and Minerals Processing Group, Department of Chemical and Biomolecular Engineering, University of Melbourne, Parkville, Victoria 3010 (Australia); Ko, S.-C. [Holcim Technology Ltd, Hagenholzstrasse 85, CH-8050 Zurich (Switzerland)

    2014-09-15

    Highlights: • We investigate a supersulfated cement for use as a nuclear waste encapsulant. • High powder fineness requires a high water content to satisfy flow requirements. • Heat generation during hydration is similar to a control cement paste. • Typical hydration products are formed resulting in a high potential for waste ion immobilisation. • Paste pH and aluminium corrosion is less than in a control cement paste. - Abstract: Composite cements based on ordinary Portland cement are used in the UK as immobilisation matrices for low and intermediate level nuclear wastes. However, the high pore solution pH causes corrosion of some metallic wastes and undesirable expansive reactions, which has led to alternative cementing systems being examined. We have investigated the physical, chemical and microstructural properties of a supersulfated cement in order to determine its applicability for use in nuclear waste encapsulation. The hardened supersulfated cement paste appeared to have properties desirable for use in producing encapsulation matrices, but the high powder specific surface resulted in a matrix with high porosity. Ettringite and calcium silicate hydrate were the main phases formed in the hardened cement paste and anhydrite was present in excess. The maximum rate of heat output during hydration of the supersulfated cement paste was slightly higher than that of a 9:1 blastfurnace slag:ordinary Portland cement paste commonly used by the UK nuclear waste processing industry, although the total heat output of the supersulfated cement paste was lower. The pH was also significantly lower in the supersulfated cement paste. Aluminium hydroxide was formed on the surface of aluminium metal encapsulated in the cement paste and ettringite was detected between the aluminium hydroxide and the hardened cement paste.

  10. The suitability of a supersulfated cement for nuclear waste immobilisation

    International Nuclear Information System (INIS)

    Collier, N.C.; Milestone, N.B.; Gordon, L.E.; Ko, S.-C.

    2014-01-01

    Highlights: • We investigate a supersulfated cement for use as a nuclear waste encapsulant. • High powder fineness requires a high water content to satisfy flow requirements. • Heat generation during hydration is similar to a control cement paste. • Typical hydration products are formed resulting in a high potential for waste ion immobilisation. • Paste pH and aluminium corrosion is less than in a control cement paste. - Abstract: Composite cements based on ordinary Portland cement are used in the UK as immobilisation matrices for low and intermediate level nuclear wastes. However, the high pore solution pH causes corrosion of some metallic wastes and undesirable expansive reactions, which has led to alternative cementing systems being examined. We have investigated the physical, chemical and microstructural properties of a supersulfated cement in order to determine its applicability for use in nuclear waste encapsulation. The hardened supersulfated cement paste appeared to have properties desirable for use in producing encapsulation matrices, but the high powder specific surface resulted in a matrix with high porosity. Ettringite and calcium silicate hydrate were the main phases formed in the hardened cement paste and anhydrite was present in excess. The maximum rate of heat output during hydration of the supersulfated cement paste was slightly higher than that of a 9:1 blastfurnace slag:ordinary Portland cement paste commonly used by the UK nuclear waste processing industry, although the total heat output of the supersulfated cement paste was lower. The pH was also significantly lower in the supersulfated cement paste. Aluminium hydroxide was formed on the surface of aluminium metal encapsulated in the cement paste and ettringite was detected between the aluminium hydroxide and the hardened cement paste

  11. Mechanism of Selenium Loss in Copper Slag

    Science.gov (United States)

    Desai, Bhavin; Tathavadkar, Vilas; Basu, Somnath

    2018-03-01

    During smelting of copper sulfide concentrate, selenium is distributed between silica-saturated iron-silicate slag and copper-iron sulfide matte. The recovery coefficients of selenium between slag and matte were determined as a function of the initial concentration of selenium at 1523 K (1250 °C) under an inert atmosphere in a vertical tubular furnace. The initial concentration of selenium was varied by the addition of metallic selenium as well as selenium dioxide to the mixture of slag and matte. Analysis of the results indicated high affinity of selenium for matte. The apparent loss of selenium with the slag was attributed to the presence of selenium-enriched matte particles entrapped in the slag, rather than dissolved SeO2. The mechanisms proposed by previous investigators were discussed and also compared with the results of the present investigation.

  12. The Iron Blast Furnace: A Study in Chemical Thermodynamics.

    Science.gov (United States)

    Treptow, Richard S.; Jean, Luckner

    1998-01-01

    Discusses the furnace from a chemical thermodynamics perspective. Examines the enthalpy, entropy, and free energy change for each reaction of importance. These properties are interpreted on the molecular level then used to deduce the conditions necessary for each reaction to occur in its intended direction. Chemical kinetics is also discussed.…

  13. The effect of pozzolans and slag on the expansion of mortars cured at elevated temperature. Part I: Expansive behaviour

    Energy Technology Data Exchange (ETDEWEB)

    T. Ramlochan; P. Zacarias; M.D.A. Thomas; R.D. Hooton [University of Toronto, Toronto, ON (Canada)

    2003-06-01

    The expansive behaviour of heat-cured mortars containing pozzolans and slag was investigated. In most cases, the addition of any amount of these materials to the mixture typically reduced the long-term expansion, slowed the rate of expansion, and delayed the onset of expansion. However, the efficacy of a particular pozzolan or slag in controlling expansion may depend on its Al{sub 2}O{sub 3} content. Metakaolin, which contains a high amount of reactive Al{sub 2}O{sub 3}, was the most effective at controlling expansion at relatively low cement replacement levels. Slag and fly ash, which are also sources of Al{sub 2}O{sub 3}, were also effective at suppressing expansion at higher replacement levels. Silica fume was less effective at controlling expansion at conventional replacement levels, and even at higher replacement levels expansion may only be delayed.

  14. CO2 sequestration by carbonation of steelmaking slags in an autoclave reactor.

    Science.gov (United States)

    Chang, E-E; Pan, Shu-Yuan; Chen, Yi-Hung; Chu, Hsiao-Wen; Wang, Chu-Fang; Chiang, Pen-Chi

    2011-11-15

    Carbon dioxide (CO(2)) sequestration experiments using the accelerated carbonation of three types of steelmaking slags, i.e., ultra-fine (UF) slag, fly-ash (FA) slag, and blended hydraulic slag cement (BHC), were performed in an autoclave reactor. The effects of reaction time, liquid-to-solid ratio (L/S), temperature, CO(2) pressure, and initial pH on CO(2) sequestration were evaluated. Two different CO(2) pressures were chosen: the normal condition (700 psig) and the supercritical condition (1300 psig). The carbonation conversion was determined quantitatively by using thermo-gravimetric analysis (TGA). The major factors that affected the conversion were reaction time (5 min to 12h) and temperature (40-160°C). The BHC was found to have the highest carbonation conversion of approximately 68%, corresponding to a capacity of 0.283 kg CO(2)/kg BHC, in 12h at 700 psig and 160°C. In addition, the carbonation products were confirmed to be mainly in CaCO(3), which was determined by using scanning electron microscopy (SEM) and X-ray powder diffraction (XRD) to analyze samples before and after carbonation. Furthermore, reaction kinetics were expressed with a surface coverage model, and the carbon footprint of the developed technology in this investigation was calculated by a life cycle assessment (LCA). Copyright © 2011 Elsevier B.V. All rights reserved.

  15. Chemical and mineralogical characterization of silicon manganese iron slag as railway ballast

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Ralph Werner Heringer; Barreto, Rairane Aparecida, E-mail: ralph@em.ufop.br, E-mail: rairanebarreto@hotmail.com [Universidade Federal de Ouro Preto (UFOP), MG (Brazil); Fernandes, Gilberto, E-mail: gilberto@unicerp.edu.br [Centro Universitário do Cerrado Patrocínio (UNICERP), Patrocínio, MG (Brazil); Sousa, Fabiano Carvalho, E-mail: fabiano.carvalho.sousa@vale.com [Vale, Belo Horizonte, MG (Brazil)

    2017-10-15

    In nature, metal ores such as iron, lead, aluminum and others are found in an impure state, sometimes oxidized and mixed with silicates of other metals. During casting, when the ore is exposed to high temperatures, these impurities are separated from the molten metal and can be removed. The mass formed by these compounds is slag. Slag is the co-product of the smelting of ore to purify metals. It may be considered a mixture of metal oxides, but may also contain metal sulphites and metal atoms in their elemental form. After it is reprocessed to separate the metals contained, the co-products of this process can be used in cement, rail ballast, road paving and various other purposes. The objective of this research work is the presentation of the chemical and mineralogical characterization tests of the silicon-manganese iron slag with the purpose of reusing the coproduct as rail ballast. X-ray diffraction tests, quantitative chemical analyzes, scanning electron microscopy and free lime content were prepared for these characterizations. The results of these tests showed the technical feasibility of using slag as rail ballast. (author)

  16. Flowsheet finalisation for immobilisation of SGHWR wastes

    International Nuclear Information System (INIS)

    Lee, D.J.

    1984-09-01

    This report summarises research and development work carried out during the year ended March 1983 on the programme for cementing the Winfrith Reactor (SGHWR) sludge. Further results from the characterisation programme are reported, together with data from the cementation programme. Formulations based on Ordinary Portland Cement (OPC), ground granulated blast furnace slag (BFS) and Pulverised Fuel Ash (PFA) have been tested. The results show that a blend of 90% BFS/10% OPC by weight, gives the best properties. Chemical pretreatment as a method for producing a stable waste form is discussed. A dewatering pretreatment to provide a sludge suitable for direct cementation is also outlined. A flowsheet for cementing the SGHWR sludge is proposed based on these laboratory and pilot scale studies. The major components required for the active plant are identified and provisional plant layouts are given. (author)

  17. The effect of steel slag as a coarse aggregate and Sinabung volcanic ash a filler on high strength concrete

    Science.gov (United States)

    Karolina, R.; Putra, A. L. A.

    2018-02-01

    The Development of concrete technology is continues to grow. The requisite for efficient constructions that are often viewed in terms of concrete mechanical behavior, application on the field, and cost estimation of implementation increasingly require engineers to optimize construction materials, especially for concrete materials. Various types of concrete have now been developed according to their needs, such as high strength concrete. On high strength concrete design, it is necessary to consider several factors that will affect the reach of the quality strength, Those are cement, water cement ratio (w/c), aggregates, and proper admixture. In the use of natural mineral, it is important for an engineer to keep an eye on the natural conditions that have been explored. So the selection of aggregates as possible is a material that is not causing nature destruction. On this experiment the use of steel slag from PT.Growth Sumatra Industry as a substitute of coarse and fine aggregate, and volcanic ash of mount Sinabung as microsilka in concrete mixture substituted to create high strength concrete that is harmless for the environment. The use of mount sinabung volcanic ash as microsilika coupled with the use of Master Glenium Sky 8614 superplasticizer. This experiment intend to compare high strength concrete based slag steel as the main constituent aggregates and high strength concrete with a conventional mixture. The research result for 28 days old concrete shows that conventional concrete compressive strength is 67.567 MPa, slag concrete 75.958 Mpa, conventional tensile strength 5.435 Mpa while slag concrete 5.053 Mpa, conventional concrete bending strength 44064.96 kgcm while concrete slag 51473.94 kgcm and modulus of conventional concrete fracture 124.978 kg / cm2 while slag concrete 145.956 kg / cm2. Both concrete slump values shows similar results due to the use of superplasticizer.

  18. The role of chemical admixtures in the formation of the structure of cement stone

    Directory of Open Access Journals (Sweden)

    Sopov Viktor

    2017-01-01

    Full Text Available The influence of sulfates and carbonates of potassium and sodium on the character of the formation of the microstructure of cement stone was studied. The role of cations in the structure formation of cement stone is shown. The efficiency of chemical additives, hardening accelerators, was estimated from the ratio of the volumes of gel and capillary micropores. The ratio of gel and capillary pores allows to determine the efficiency coefficient of the action of chemical additives. It is shown that the potassium carbonate for Portland cement is the most effective additive for hardening in terms of microstructure modification, and potassium sulfate for slag Portland cement.

  19. Dissolution of steel slags in aqueous media.

    Science.gov (United States)

    Yadav, Shashikant; Mehra, Anurag

    2017-07-01

    Steel slag is a major industrial waste in steel industries, and its dissolution behavior in water needs to be characterized in the larger context of its potential use as an agent for sequestering CO 2 . For this purpose, a small closed system batch reactor was used to conduct the dissolution of steel slags in an aqueous medium under various dissolution conditions. In this study, two different types of steel slags were procured from steel plants in India, having diverse structural features, mineralogical compositions, and particle sizes. The experiment was performed at different temperatures for 240 h of dissolution at atmospheric pressure. The dissolution rates of major and minor slag elements were quantified through liquid-phase elemental analysis using an inductively coupled plasma atomic emission spectroscopy at different time intervals. Advanced analytical techniques such as field emission gun-scanning electron microscope, energy-dispersive X-ray, BET, and XRD were also used to analyze mineralogical and structural changes in the slag particles. High dissolution of slags was observed irrespective of the particle size distribution, which suggests high carbonation potential. Concentrations of toxic heavy metals in the leachate were far below maximum acceptable limits. Thus, the present study investigates the dissolution behavior of different mineral ions of steel slag in aqueous media in light of its potential application in CO 2 sequestration.

  20. Uranium recovery from slags of metallic uranium