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Sample records for limestone slag clay

  1. 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 an

  2. Evaluation of steel slag and crushed limestone mixtures as subbase material in flexible pavement

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    Ahmed Ebrahim Abu El-Maaty Behiry

    2013-03-01

    Full Text Available Steel slag is produced as a by-product during the oxidation of steel pellets in an electric arc furnace. This by-product that mainly consists of calcium carbonate is broken down to smaller sizes to be used as aggregates in pavement layers. They are particularly useful in areas where a good-quality aggregate is scarce. This research study was conducted to evaluate the effect of quantity of steel slag on the mechanical properties of blended mixes with crushed limestone aggregates, which used as subbase material in Egypt. Moreover, a theoretical analysis was employed to estimate the resistance for failure factors such as vertical deformations, vertical and radial stresses and vertical strains of subbase under overweight trucks loads. These loads cause severe deterioration to the pavement and thus reduce its life. The results indicated that the mechanical characteristics, and the resistance factors were improved by adding steel slag to the crushed limestone.

  3. Stabilization effects of surplus soft clay with cement and GBF slag

    Institute of Scientific and Technical Information of China (English)

    LU Jiang; Chirdchanin MODMOLTIN; Katsutada ONITSUKA

    2004-01-01

    Utilization of industrial waste and surplus construction soft clay as construction material was recommended, and many attempts at geotechnical waste utilization were undertaken. This study aimed at the application of cement and a kind of industrial wastes, i.e. granulated blast furnace slag, on stabilization of surplus soft clay. The results showed that the cement and slag can successfully stabilize Ariake clays even though this high organic clay fails to be stabilized by lime and cement. Addition of slag in cement for stabilization induces higher strength than cement alone for longer curing time. The application of the cement with slag is more suitable than cement alone for stabilization because of economical consideration.

  4. The Influence of Calcined Clay Pozzolan, Low-Cao Steel Slag and Granite Dust On the Alkali-Silica Reaction in Concrete

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    James Sarfo-Ansah

    2015-08-01

    Full Text Available The influence of low CaO steel slag, calcined clay and granite dust on the alkali-silica reaction was investigated over a period of 35 days under accelerated curing conditions. The mineral admixtures were used to replace varying portions of high alkali Portland limestone cement up to an admixture content of 25% in order to study their effect on the alkali-silica reaction (ASR. Portland limestone cement used for the study had a total Na2Oeq of 4.32. XRD analysis of hydrated mortar bar samples confirmed the formation of an expansive sodium silica gel in the reference Portland cement mortar bar as the agent responsible for ASR. Stable calcium silicates were formed in the mortar bars containing calcined clay in increasing quantities whilst the presence of the sodium silicate gel decreased.The occurrence of these stable silicates in hydrated samples containing steel slag and granite dust was however minimal, compared to calcined clay cement mortars. The highest expansion was recorded for granite dust mortar bars, reaching a maximum of 25.98% at 35 days. Mortar-bar expansion decreased as calcined clay content in the cement increased;mortar bars with 25% calcined clay were the least expansive recording expansion less than 0.1% at all test ages. Whilst the expansion was reduced by between 42.5% and 107.8% at 14 days with increasing calcined clay content, expansion rather increased between 36.8% and 169.5% at 14 days with increasing granite dust content.Steel slag mortar bars experienced reduction in 14 days expansion between 14.3% - 46.2%.The study confirms that steel slag and calcined clay pozzolan have greater influence on ASR in mortar bars than granite dust and shows that calcined clay and low CaO steel slag could be considered as remedial admixtures for ASR at replacement levels of 25% and 15% respectively.

  5. Soil chemical characteristics, biomass production and levels of nutrient and heavy metals in corn plants according to doses of steel slag and limestone

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    Luiz Carlos Santos Caetano

    Full Text Available ABSTRACT Steel slag presents potential for neutralizing the soil acidity instead of limestone and for supplying nutrients for plants. The objective of this work was to study the effect of steel slag on soil chemical characteristics, biomass production, and contents of nutrients and of heavy metals on dry matter of corn plants. The levels of P, K, Na, Ca, Mg, Cu, Fe, Zn, Mn, Si, Cd, Cr, Pb, and Ni were determined in steel slag and limestone (for comparison purposes and the growth of corn plants under increasing doses of slag and limestone (0 to 10 t ha-1 was evaluated. Steel slag presented higher levels of P, Fe, Zn, Mn, and Si when compared with limestone. No difference was found in the content of heavy metals of slag and limestone, except for Cr, which was higher in the slag. Limestone provided the greatest increase of soil pH over time. Slag increased the content of P, Si, and soil micronutrient, while limestone was more efficient in increasing the content of Mg. The levels of heavy metals in the soil increased with the application of slag, but they remained below critical level within agricultural parameters. Slag and limestone presented a similar effect on the increase of the initial production of corn biomass. The levels of heavy metals in dry matter of corn plants under increasing doses of slag and limestone were below the critical levels of the toxicity of these elements on most plants.

  6. The Influence of Calcined Clay Pozzolan, Low-Cao Steel Slag and Granite Dust On the Alkali-Silica Reaction in Concrete

    OpenAIRE

    James Sarfo-Ansah; Eugene Atiemo

    2015-01-01

    The influence of low CaO steel slag, calcined clay and granite dust on the alkali-silica reaction was investigated over a period of 35 days under accelerated curing conditions. The mineral admixtures were used to replace varying portions of high alkali Portland limestone cement up to an admixture content of 25% in order to study their effect on the alkali-silica reaction (ASR). Portland limestone cement used for the study had a total Na2Oeq of 4.32. XRD analysis of hydrated mortar...

  7. Combination of Slag, Limestone and Sedimentary Apatite in Columns for Phosphorus Removal from Sludge Fish Farm Effluents

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    Florent Chazarenc

    2010-08-01

    Full Text Available Laboratory scale studies have repeatedly reported high P-retention in slag, a by-product of the steel manufacturing industry. Thus, it has emerged as a potential material to increase P-removal from constructed wetlands (CWs. However, several limitations were highlighted by field experiments, including the high pH of treated water and clogging. We hypothesized that the addition of sedimentary rocks to slag would preserve P-removal properties while reducing the pH of treated water. Four 2.5 L-columns were filled with 100% apatite (column A; a 50% weight each mixture of limestone with apatite (column B; 10% steel slag located at the inlet, plus 45% limestone mixed with 45% apatite (column C; and a mixture of steel slag (10%, limestone (45% apatite (45% (column D. A synthetic effluent (26 mg P/L and a reconstituted sludge fish farm effluent containing 97 mg/L total suspended solids (TSS, 220 mg/L chemical oxygen demand (COD and 23.5 mg P/L phosphorus (P were applied sequentially during 373 and 176 days, under saturated flow conditions and 12–24 hours hydraulic residence time (HRT, respectively. Treatment performance, P-removal, pH and calcium (Ca2+ were monitored. Results indicated that columns that contained 10% weight steel slag resulted in a higher P retention capacity than the columns without steel slag. The highest P removal was achieved in column C, containing a layer of slag in the inlet zone, 45% apatite and 45% limestone. Feeding the columns with a reconstituted fish farm effluent led to biofilm development, but this had little effect on the P-removal. A combination of slag and sedimentary rocks represents a promising filtration material that could be useful downstream of CWs to further increase P-removal.

  8. Influence of clay swelling on the mechanical behaviour of Egyptian Helwan limestone

    Science.gov (United States)

    Aly, Nevin

    2016-04-01

    Clay minerals exist naturally in the majority of different Egyptian limestones types. Changes in the dimensions of clays during swelling / shrinking process induced by changes in the environmental conditions can result in acceleration the deterioration of the hosting stone. Petrographic investigation by scanning - electron microscope (SEM) of Helwan limestone (biomicritic limestone) revealed distribution of a typical smectite morphology (curled - leaf shape) beside abundance of glauconite pellets within the stone material. The clay frication extracted from Helwan reached 10% and oriented aggregates samples were analyzed by X- ray diffraction (XRD) and confirmed the identification of smectite as the main mineral in the clay frication. To study the effect of the clay content on the mechanical behavior of Helwan limestone, hygric swelling test was performed at first by using displacement sensor and then the effect of multiple wetting/ drying cycles on the stone strength was determined using unconfined compressive strength (UCS). Results revealed that there was a significant correlation between degree of swelling of the clay and strength of the limestone.

  9. 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

  10. Influence of Water Content on the Mechanical Behaviour of Limestone: Role of the Clay Minerals Content

    Science.gov (United States)

    Cherblanc, F.; Berthonneau, J.; Bromblet, P.; Huon, V.

    2016-06-01

    The mechanical characteristics of various sedimentary stones significantly depend on the water content, where 70 % loss of their mechanical strengths can be observed when saturated by water. Furthermore, the clay fraction has been shown to be a key factor of their hydro-mechanical behaviour since it governs for instance the hydric dilation. This work aims at investigating the correlations between the clay mineral content and the mechanical weakening experienced by limestones when interacting with water. The experimental characterization focuses on five different limestones that exhibit very different micro-structures. For each of them, we present the determination of clay mineral composition, the sorption isotherm curve and the dependences of tensile and compressive strengths on the water content. It emerges from these results that, first, the sorption behaviour is mainly governed by the amount of smectite layers which exhibit the larger specific area and, second, the rate of mechanical strength loss depends linearly on the sorption capacity. Indeed, the clay fraction plays the role of a retardation factor that delays the appearance of capillary bridges as well as the mechanical weakening of stones. However, no correlation was evidenced between the clay content and the amplitude of weakening. Since the mechanisms whereby the strength decreases with water content are not clearly established, these results would help to discriminate between various hypothesis proposed in the literature.

  11. Utilisation of IGCC slag and clay steriles in soft mud bricks (by pressing) for use in building bricks manufacturing.

    Science.gov (United States)

    Acosta, A; Iglesias, I; Aineto, M; Romero, M; Rincón, J Ma

    2002-01-01

    The subject of this study is the application to the construction of soft mud bricks (also known as pressed bricks), both green and heat-treated bodies, built from raw materials from Santa Cruz de Mudela, Ciudad Real, and IGCC slag from the power central of Puertollano (Ciudad Real, Spain). For this purpose, industrial level tests have been performed: the production of these kind of bricks from mixes of waste from ores of construction clays and to significant fraction of different ratios and clay granulometries mixed with IGCC slag. The results of this experimentation suggests that not only can IGCC slag be applied to a ceramic process, but also its use gives several advantages, as water and energy savings, as well as improvements on the final properties of products.

  12. The Use of Converter Slag (Magnetite and Bentonite Clay for Amoxicillin Adsorption from Polluted Water

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    Fernanda Maichin

    2013-11-01

    Full Text Available The presence of pharmaceuticals compounds in the aquatic environment has attracted much interest from the academic community, since these compounds are potential endocrine disrupters and persist in the environment causing irreversible damage to the ecosystem. In Brazil little research has been conducted to measure, treat and remove β-lactam antibiotics such as amoxicillin present in surface water. Thus, the development and implementation of new treatment method which allow the removal or reduction of these compounds in surface waters are need. This study, focus on the development of low cost adsorbent material composed by steel manufacture converter slag (magnetite and bentonite clay to adsorb and remove amoxicillin (amox from water under laboratory conditions. To demonstrate the favorable aspects, the study was performed by experimental calculations of thermodynamics, kinetic and empirical model. The obtained results were similar with others found in literature which indicate the steel industry residue -magnetite and bentonite clay can be use to remove amoxicillin, with approximately 50% of removal percentage.

  13. Chemical study of limestone and clay for cement manufacturing in Darukhula, Nizampur District,Nowshera, North West Frontier Province(N.W.F.P.), Pakistan

    Institute of Scientific and Technical Information of China (English)

    Khurshid Ali; Noor-ul-Amin; M.Tahir Shah

    2008-01-01

    Limestone and clay samples were collected from Darukhula and adjoining areas of the Nizampur District,Nowshera, N.W.F.P., Pakistan, and analyzed for different parameters in order to search for new reserves of suitable material for the manufacture of different types of cements in N.W.EP. It was found that the area under study contains three types of limestones, including high grade limestone, Darukhula limestone and siliceous limestone, which contain 53%, 49.03% and 45.19% CaO, respectively, and three types of clay, including maroon color, yellow to yellowish-green color and green color clay containing 57.76%, 65.47% and 61.24% SiO2, respectively. Chemical analysis of the limestone and clay samples collected from the deposits in the area under study showed that all the dements found in these samples are within the range of permissible limits for the production of high-strength Portland cement,sulphate resisting cement and white cement. This paper covers the detailed version of the potential raw material deposits at Darukhula and adjoining areas of the Nizampur District.

  14. Characterisation of the sintering behaviour of Waelz slag from electric arc furnace (EAF) dust recycling for use in the clay ceramics industry.

    Science.gov (United States)

    Quijorna, N; de Pedro, M; Romero, M; Andrés, A

    2014-01-01

    Waelz slag is an industrial by-product from the recovery of electric arc furnace (EAF) dust which is mainly sent to landfills. Despite the different chemical and mineralogical compositions of Waelz slag compared to traditional clays, previous experiments have demonstrated its potential use as a clay substitute in ceramic processes. Indeed, clayey products containing Waelz slag could improve mechanical and environmental performance, fixing most of the metallic species and moreover decreasing the release of some potential pollutants during firing. However, a deeper understanding of the complex phase transformations during its thermal treatment and the connection of this behaviour with the end properties is desirable in order to explain the role that is played by the Waelz slag and its potential contribution to the ceramic process. For this purpose, in the present study, the chemical, mineralogical, thermal and environmental behaviour of both (i) unfired powdered samples, and (ii) pressed specimen of Waelz slag fired up to different temperatures within the typical range of clay based ceramic production, has been studied. The effect of the heating temperature on the end properties of the fired samples has been assessed. In general, an increase of the firing temperature promotes sintering and densification of the products and decreases the open porosity and water absorption which also contributes to the fixation of heavy metals. On the contrary, an increase in the leaching of Pb, Cr and Mo from the fired specimens is observed. This can be attributed to the creation of Fe and Ca molybdates and chromates that are weakly retained in the alkali matrix. On the other side, at temperature above 950 °C a weight gain related to the emission of evolved gases is observed. In conclusion, the firing temperature of the ceramic process is a key parameter that affects not only the technical properties but also strongly affects the leaching behaviour and the process emissions.

  15. Multivariate mixed effect of limestone powder-fly ash-slag powder on the performance of concrete%石灰石粉-粉煤灰-矿粉多元复掺对混凝土性能的影响

    Institute of Scientific and Technical Information of China (English)

    冯庆革; 杨阳; 乔永平; 蒋玉柳; 王燚

    2014-01-01

    研究了石灰石粉按不同比例分别取代矿粉和粉煤灰的多元复掺方式以及CTF混凝土增效剂的掺入对混凝土工作性能、强度和抗氯离子渗透性的影响。试验结果表明:在适宜掺量下,石灰石粉等量替代粉煤灰或矿粉,可以有效地改善工作性能,而随着替代量的增加,工作性能呈先增后减的趋势;石灰石粉取代粉煤灰或矿粉的量在50%之内时,对混凝土各龄期强度影响不大,但完全替代时,对混凝土的后期强度发展不利;石灰石粉替代粉煤灰或矿粉对混凝土的抗氯离子渗透性不利,电通量随替代量增加而增大;CTF混凝土增效剂的掺入可以有效地改善混凝土的和易性,提高强度以及抗氯离子渗透性。%Slag powder and fly ash were replaced with limestone powder by different quality ratios ,in this way,it discussed the influ-ence of the combined use of mineral additive and the CTF concrete synergist,on the workability,strength and the resistance to chlorine ion penetration of concrete.Results of the trial indicated that under the appropriate mix content limestone powder equally replacing fly ash or slag,can effectively improve the working performance,the workability increased firstly and then decreased as the increment of re-placement .Limestone powder replaced the amount of fly ash or slag within substitution ratio 50%,it did not much affect the strength of concrete,but completely replacing,the later strength development of concrete developed slowly.Limestone powder instead of fly ash or slag on the resistance to chloride ion permeability of concrete,electric flux increased with increasing amount of replacement.The CTF concrete synergist can effectively improve the workability,enhance the strength and the resistance to chloride ion permeability of concrete.

  16. Experimental study on unconfined compressive strength of clays stabilized with fly ash and slag%粉煤灰炉渣加固土的室内无侧限抗压强度试验研究

    Institute of Scientific and Technical Information of China (English)

    庄心善; 王功勋; 朱瑞赓; 田苾

    2005-01-01

    This paper presents the experimental results on unconfined compressive strength (UCS) of the clays stabilized with industrial wastes such as fly ash and slag. Three kinds of the compound clays are produced with different proportions of fly ash, clay, sand, mud and slag, and then the compound clays are reinforced by cement, lime, and their combination respectively. The experimental results obtained from the laboratory tests show that the compound clays with fly ash can be best reinforced by cement instead of lime or combination of cement and lime. The relationship among UCS, curing time and cement content has been verified by the laboratory test results in this study. For the compound clays with slag, lime is the most suitable stabilizing agent, and the optimal lime content is around 15% in weight for the soil stabilization in Wuhan areas.%给出了用粉煤灰、炉渣等工业废料加固土的室内无侧限抗压强度试验结果,分析了加固土无侧限抗压强度与外加剂掺量、养护龄期之间的影响规律,得出了针对不同工业废料加固土所用外加剂的最佳掺量.

  17. Mineral resource of the month: ferrous slag

    Science.gov (United States)

    ,

    2009-01-01

    The article offers information on mineral resource ferrous slag. Ferrous slag is produced through the addition of materials such as limestone and dolomite to blast and steel furnaces to remove impurities from iron ore and to lower the heat requirements for processes in iron and steel making. It is stated that the method of cooling is important for the market uses and value of ferrous slag. Some types of slag can be used in construction, glass manufacturing and thermal insulation.

  18. Basal Ottawa Limestone, Chattanooga Shale, Floyd Shale, Porters Creek Clay, and Yazoo Clay in parts of Alabama, Mississippi and Tennessee as potential host rocks for underground emplacement of waste

    Energy Technology Data Exchange (ETDEWEB)

    Mellen, F.F.

    1976-02-28

    Impermeable rock units, preferably at least 500 feet thick and lying 1000 to 3000 feet below land surface, were sought in the region consisting roughly of the western /sup 3///sub 5/ths of Tennessee and the northern /sup 3///sub 5/ths of Alabama and Mississippi. All rock sequences, Cambrian through Eocene, were examined in varying detail, except the Cretaceous Selma Chalk and except the diapiric salt. These rocks were studied for their relative impermeable homogeneity, their continuity, their background of structural and seismic stability and their hydrologic associations. The Central Mississippi Ridge of north-central Mississippi is overlain by a long-stable mass of Porters Creek Clay 500-700 feet thick, in an area roughly 50-60 miles wide and about 150 miles long. The Yazoo Clay, where best developed in the west-central and southwest part of Mississippi, is in the 400-500 foot thickness range, but locally exceeds 500 feet. The entire area mapped is underlain by the Louann Salt which has produced many deep-seated salt domes and numerous piercement salt domes. Salt flow has complicated shallow structural geology throughout that area. The Chattanooga Shale rarely exceeds 60 feet in thickness in the region studied and is generally much thinner and is absent in many places. In the lower part of the Middle Ordovician (Ottawa Megagroup), the Murphreesboro and associated dense limestones appear to offer a potential disposal unit 250-400 feet thick, having the advantages of rock competency and freedom from association with prolific aquifers in the overburden or beneath. Other less conspicuous stratigraphic units are reviewed.

  19. Removing nitrogen in fecal sewage with steel slag-limestone constructed wetland%钢渣-灰岩人工湿地脱除粪便污水高氮素的实验研究

    Institute of Scientific and Technical Information of China (English)

    黄玲; 何绪文

    2012-01-01

    构建小试系统研究了钢渣-灰岩垂直潜流人工湿地对粪便污水中高浓度氮素的降解效果。同时比较分析了填料填铺方式和表层填料对钢渣-灰岩垂直潜流湿地降解粪便污水氮素效能的影响。结果表明:当原水氨氮在42.72~272.60 mg/L,总氮在107.40~689.35 mg/L内,钢渣-灰岩垂直潜流人工湿地出水氨氮和总氮浓度可分别达到13.57 mg/L和62.83 mg/L;从长期效果来看,大级配差的正反粒径混合填铺的填料结构更有利于钢渣-灰岩人工湿地保持氮素降解效能;表层的基质材料选择要充分考虑渗透性和复氧能力;钢渣不但对氨氮有吸附作用,而且为氨氮的挥发和硝化/反硝化作用创造有利环境;灰岩在钢渣协助下溶出钙离子以利于氨氮的阳离子交换,同时为铁自养反硝化菌和脱硫杆菌的自养反硝化作用提供碳源。%The purpose of this paper is to study the degradation effect of high concentration nitrogen in fecal sewage with steel slag-limestone constructed wetland.Different factors experiments impacting treatment effect were operated,such as fillings structure,surface filling and so on.The experimental results indicated that the NH3-N and TN concentration of constructed wetland effluent attained to 13.57 mg/L and 62.83 mg/L when the NH3-N and TN concentration ranges of raw water were 42.72~272.60 mg/L and 107.40~689.35 mg/,respentively.Then at the base of assuring effluent quality and improving quantity of treated wastewater,60 h is the best intermittent inflow time.The bed structure having larger size difference which was mixed progressively-sized filling with anti-sized filling was more benefit for keeping long-time better degradation effect on nitrogen,and the surface filling mixed 40% soil and 60% washing sand was also the best choice because of its granularity penetrability,ability to restore oxygen.Steel slag can creat an environment which was not only benefit for adsorption and

  20. Efeito da escória de siderurgia e calcário na disponibilidade de fósforo de um Latossolo Vermelho-Amarelo cultivado com cana-de-açúcar Effect of slag and limestone on the availability of phosphorus of an Oxisol planted with sugarcane

    Directory of Open Access Journals (Sweden)

    Renato de Mello Prado

    2001-09-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito da escória de siderurgia e calcário na concentração do P disponível em um Latossolo Vermelho-Amarelo, cultivado com cana-de-açúcar (Saccharum spp., em Ituverava, SP. Foram aplicados calcário calcítico e a escória de siderurgia, objetivando elevar a saturação por bases a 50%, 75% e 100%, e usou-se testemunha (sem correção. O efeito linear da escória de siderurgia no P disponível do solo, em contraste com a ausência de relação quando se aplicou calcário, sugere que o efeito positivo da escória de siderurgia se deve mais ao efeito do silicato, de saturar os sítios de adsorção de P, do que ao efeito de aumento do pH.The aim of this work was to evaluate the effect of slag and limestone, on the available P concentration of the soil planted with sugarcane. A field experiment was conducted in Ituverava, SP, Brazil, in a Red-Yellow Oxisol. Calcitic limestone and the slag were added in order to increase the base saturation to 50%, 75% and 100%, in addition to the control without correction. The linear effect of the slag on the soil available P, contrasting the lack of relationship when the limestone was applied, suggests that the positive effect of the slag is mainly due to the silicate effect than to the pH effect.

  1. Influence of clay particles on Al{sub 2}O{sub 3} and TiO{sub 2} nanoparticles transport and retention through limestone porous media: measurements and mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Bayat, Ali Esfandyari, E-mail: ali.esfandiari.bayat@gmail.com; Junin, Radzuan [Universiti Teknologi Malaysia, Department of Petroleum Engineering, Faculty of Petroleum and Renewable Energy Engineering (Malaysia); Mohsin, Rahmat [Universiti Teknologi Malaysia, UTM-MPRC Institute for Oil and Gas, N29A, Lengkuk Suria (Malaysia); Hokmabadi, Mehrdad [Universiti Teknologi Malaysia, Department of Petroleum Engineering, Faculty of Petroleum and Renewable Energy Engineering (Malaysia); Shamshirband, Shahaboddin [University of Malaya, Department of Computer System and Information Technology, Faculty of Computer System and Information Technology (Malaysia)

    2015-05-15

    Utilization of nanoparticles (NPs) for a broad range of applications has caused considerable quantities of these materials to be released into the environment. Issues of how and where the NPs are distributed into the subsurface aquatic environments are questions for those in environmental engineering. This study investigated the influence of three abundant clay minerals namely kaolinite, montmorillonite, and illite in the subsurface natural aquatic systems on the transport and retention of aluminum oxide (Al{sub 2}O{sub 3}, 40 nm) and titanium dioxide (TiO{sub 2}, 10–30 nm) NPs through saturated limestone porous media. The clay concentrations in porous media were set at 2 and 4 vol% of the holder capacity. Breakthrough curves in the columns outlets were measured using a UV–Vis spectrophotometer. It was found that the maximum NPs recoveries were obtained when there was no clay particle in the porous medium. On the other hand, increase in concentration of clay particles has resulted in the NPs recoveries being significantly declined. Due to fibrous structure of illite, it was found to be more effective for NPs retention in comparison to montmorillonite and kaolinite. Overall, the position of clay particles in the porous media pores and their morphologies were found to be two main reasons for increase of NPs retention in porous media.

  2. The Research Process on Converter Steelmaking Process by Using Limestone

    Science.gov (United States)

    Tang, Biao; Li, Xing-yi; Cheng, Han-chi; Wang, Jing; Zhang, Yun-long

    2017-08-01

    Compared with traditional converter steelmaking process, steelmaking process with limestone uses limestone to replace lime partly. A lot of researchers have studied about the new steelmaking process. There are much related research about material balance calculation, the behaviour of limestone in the slag, limestone powder injection in converter and application of limestone in iron and steel enterprises. The results show that the surplus heat of converter can meet the need of the limestone calcination, and the new process can reduce the steelmaking process energy loss in the whole steelmaking process, reduce carbon dioxide emissions, and improve the quality of the gas.

  3. Limestone Caverns

    Science.gov (United States)

    Powell, Richard L.

    1970-01-01

    Describes the origin of limestone caverns, using Mammoth Cave as an example, with particular reference to the importance of groundwater information of caverns, the present condition of groundwater, and how caverns develop within fluctuating groundwater zones. (BR)

  4. Limestone Paradise

    Institute of Scientific and Technical Information of China (English)

    BRUCE CONNOLLY

    2004-01-01

    <正> In Guangxi there is an area I have frequently referred to as ’Heaven on Earth’. It is the limestone district stretching along the valley of the Li River from the popular tourist city of Guilin to the scenic wonderland of tiny, laid-back, Yangshuo.Produced 300 million years ago when an ancient sea covered this area, the limestone is formed from the compressed fossilised remains of sea creatures. The movements of the continents caused the earth to rise up and the sea disappeared.

  5. Characterization of DNAPL Source Zone Arcgitecture in Clay Till and Limestone Bedrock by Integrated Site Investigations with Innovative and Current Techniques

    DEFF Research Database (Denmark)

    Broholm, Mette Martina; Janniche, Gry Sander; Fjordbøge, Annika Sidelmann

    , particulary from soft zones in contact with flint beds, was caused by the water flush applied during drilling and likely also resulted in loss of DNAPL from high permeability features. Hence, coring and subsampling for quantitative analysis and SudanIV tests continues to be an unresolved challenge......Characterization of dense non-aqueous phase liquid (DNAPL) source zone architecture is essential to develop accurate site specific conceptual models, delineate and quantify contaminant mass, perform risk assessment, and select and design remediation alternatives. The activities of a distribution...... in the limestone aquifer included coring with discrete subsampling for quantitative analysis, SudanIV hydrophobic colour test, PID and geologic descriptions; NAPL and FACT FLUTe exposure and discrete FACT subsampling and analysis; FLUTe liner hydraulic conductivity profiling; Water-FLUTe installation...

  6. Faults architecture and growth in clay-limestone alternation. Examples in the S-E Basin alternations (France) and numerical modeling; Architecture et croissance des failles dans les alternances argilo-calcaires. Exemples dans les alternances du Bassin du Sud-Est (France) et modelisation numerique

    Energy Technology Data Exchange (ETDEWEB)

    Roche, Vincent

    2011-10-28

    The following work has been carried out in the framework of the studies conducted by IRSN in support of its safety evaluation of the geological disposal programme of high and intermediate level, long-lived radioactive waste. Such a disposal is planned to be hosted by the Callovian-Oxfordian indurate clay formation between two limestone formations in eastern Paris basin, France. Hypothetical faults may cross-cut this layered section, decreasing the clay containment ability by creating preferential pathways for radioactive solute towards limestones. This study aims at characterising the fault architecture and the normal fault growth in clay/limestone layered sections. Structural analysis and displacement profiles have been carried out in normal faults crossing several decimetres to metre thick sedimentary alternations in the South-Eastern Basin (France) and petrophysical properties have been determined for each layer. The studied faults are simple fault planes or complex fault zones showing are significantly controlled by the layering. The analysis of the fault characteristics and the results obtained on numerical models enlighten several processes such as fault nucleation, fault restriction, and fault growth through layered section. Some studied faults nucleated in the limestone layers, without using pre-existing fractures such as joints, and according to our numerical analysis, a strong stiffness, a low strength contrast between the limestone and the clay layer, and/or s a greater thickness of the clay layer are conditions which favour nucleation of faults in limestone. The range of mechanical properties leading to the fault nucleation in one layer type or another was investigated using a 3D modelling approach. After its nucleation, the fault propagates within a homogeneous medium with a constant displacement gradient until its vertical propagation is stopped by a restrictor. The evidenced restrictors are limestone-clay interfaces or faults in clays, sub

  7. Potential degradation mechanisms of stylolitic limestones

    Science.gov (United States)

    Aly, Nevin; Török, Ákos; Aguilar Sanchez, Asel Maria; Wangler, Timothy

    2017-04-01

    Stylolites are irregular rough surfaces formed due to the pressure-solution process and commonly developed in carbonate stones. Stylolite formation is usually accompanied by the accumulation of insoluble residues i.e. organic matter, oxides and clays on the stylolitic surfaces. The amount and the type of these clays may play a significant role in the deterioration of the host stone. This study presents the characterization of various stylolitic limestones containing different amounts of clays and used extensively as building cladding and decorative stones in Israel and in Hungary. The first case study focuses on two lithotypes from Israel, both of them are biocalcirudite-calcarenite with high amount of bioclasts. Abundance of open stylolites filled partially with organic matter and minor amounts of clays exist in the first lithotype with cream colour. The second lithotype has grey colour and contains organic matter and pyrite dispersed throughout the stone and more concentrated within the stylolites along with clay and dolomite crystal. Both lithotypes exhibit signs of decay just after a few years of exposure. The first studied Hungarian limestone is a red Jurassic carbonate (ammonitico rosso type) that was formed in pelagic marine environment. This wackestone contains abundant pelagic microfossils. The limestone has been used from Roman period in Central Europe in Hungary, Romania and Poland. The stylolites are seen as darker bedding parallel seams containing minor amounts of clay and hematite. Small amount of clay is also found in isolated nodules. The second Hungarian lithotype is also a Jurassic limestone which contains less clay than the previous one. This yellowish-white limestone is strongly cemented and contains red intersecting stylolites that do not follow the bedding planes or stratification. The main aim of this study is to understand and evaluate the damage mechanism of different stylolitic limestones. Samples were exposed to multiple thermal and wet

  8. Artificial neural network model to predict slag viscosity over a broad range of temperatures and slag compositions

    Energy Technology Data Exchange (ETDEWEB)

    Duchesne, Marc A. [Chemical and Biological Engineering Department, University of Ottawa, 161 Louis Pasteur, Ottawa, Ont. (Canada); CanmetENERGY, 1 Haanel Drive, Ottawa, Ontario (Canada); Macchi, Arturo [Chemical and Biological Engineering Department, University of Ottawa, 161 Louis Pasteur, Ottawa, Ont. (Canada); Lu, Dennis Y.; Hughes, Robin W.; McCalden, David; Anthony, Edward J. [CanmetENERGY, 1 Haanel Drive, Ottawa, Ontario (Canada)

    2010-08-15

    Threshold slag viscosity heuristics are often used for the initial assessment of coal gasification projects. Slag viscosity predictions are also required for advanced combustion and gasification models. Due to unsatisfactory performance of theoretical equations, an artificial neural network model was developed to predict slag viscosity over a broad range of temperatures and slag compositions. This model outperforms other slag viscosity models, resulting in an average error factor of 5.05 which is lower than the best obtained with other available models. Genesee coal ash viscosity predictions were made to investigate the effect of adding Canadian limestone and dolomite. The results indicate that magnesium in the fluxing agent provides a greater viscosity reduction than calcium for the threshold slag tapping temperature range. (author)

  9. 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

  10. Limestone compaction: an enigma

    Science.gov (United States)

    Shinn, Eugene A.; Halley, Robert B.; Hudson, J. Harold; Lidz, Barbara H.

    1977-01-01

    Compression of an undisturbed carbonate sediment core under a pressure of 556 kg/cm2 produced a “rock” with sedimentary structures similar to typical ancient fine-grained limestones. Surprisingly, shells, foraminifera, and other fossils were not noticeably crushed, which indicates that absence of crushed fossils in ancient limestones can no longer be considered evidence that limestones do not compact.

  11. Mineral precipitation and dissolution at two slag-disposal sites in northwestern Indiana, USA

    Science.gov (United States)

    Bayless, E.R.; Schulz, M.S.

    2003-01-01

    Slag is a ubiquitous byproduct of the iron- and steel-refining industries. In northwestern Indiana and northeastern Illinois, slag has been deposited over more than 52 km2 of land surface. Despite the widespread use of slag for fill and construction purposes, little is known about its chemical effects on the environment. Two slagdisposal sites were examined in northwestern Indiana where slag was deposited over the native glacial deposits. At a third site, where slag was not present, background conditions were defined. Samples were collected from cores and drill cuttings and described with scanning electron microscopy and electron microprobe analysis. Ground-water samples were collected and used to assess thermodynamic equilibria between authigenic minerals and existing conditions. Differences in the mineralogy at background and slag-affected sites were apparent. Calcite, dolomite, gypsum, iron oxides, and clay minerals were abundant in native sediments immediately beneath the slag. Mineral features indicated that these minerals precipitated rapidly from slag drainage and co-precipitated minor amounts of non-calcium metals and trace elements. Quartz fragments immediately beneath the slag showed extensive pitting that was not apparent in sediments from the background site, indicating chemical weathering by the hyperalkaline slag drainage. The environmental impacts of slag-related mineral precipitation include disruption of natural ground-water flow patterns and bed-sediment armoring in adjacent surface-water systems. Dissolution of native quartz by the hyperalkaline drainage may cause instability in structures situated over slag fill or in roadways comprised of slag aggregates.

  12. 锰渣陶土外墙保温轻质瓷砖的制备及力学性能分析%Analysis on Mechanical Properties and Preparation of Manganese Slag Clay Composite Exterior Wall Thermal Insulation of Lightweight Tiles

    Institute of Scientific and Technical Information of China (English)

    梁峙; 庄旭; 肖扬; 马捷; 顾烨; 倪振威

    2015-01-01

    Taking manganese slag ,clay ,silicon carbide and refractory fiber as the main raw material , the lightweight tiles for exterior wall thermal insulation wall insulation with manganese slag clay were pre‐pared through mixing ,molding ,drying and firing processes .The flexural strength and bibulous rate of the sample were analyzed by measuring different manganese slag content and sintering temperature .The exper‐imental data showed that :under the environment of nitrogen sintering ,the flexural strength and bibulous rate got to the best effects with 20% manganese slag content and the 850 ℃ sintering temperature . Through XRD analysis ,the samples still contained large amounts of manganese elements which showed that they retained the original forms of manganese with a series of excellent performance such as high tem‐perature resistance ,strong flexural strength and corrosion resistance .%以锰渣、陶土、碳化硅、耐火纤维为主要原料,经混合、成型、干燥和烧成等工艺制得锰渣陶土外墙保温轻质瓷砖。实验通过测定不同的锰渣含量和烧结温度,对样品的抗折强度、吸水率进行分析。实验结果表明:当锰矿渣粉质量分数20%、氮气环境下烧结、烧结温度850℃时,产品吸水率、抗折强度达到最佳效果。通过XRD分析得知产品含有大量的锰元素,表明试验在高温下保留了锰的原有形态。试验样品具有耐高温、高强度、抗腐蚀性等一系列优良性能。

  13. Estudo da potencialidade da aplicação de uma argila contaminada com calcário na produção de placas cerâmicas Study of the potentiality of the application of a contaminated clay with limestone in the production of ceramic plates

    Directory of Open Access Journals (Sweden)

    R. A. L. Soares

    2012-12-01

    Full Text Available Na região da cidade de Teresina, PI, encontra-se uma grande quantidade de jazidas de argilas de queima vermelha usadas na produção de cerâmica estrutural, sendo o principal motivo da instalação de um pólo cerâmico nesta região. Porém muitas destas jazidas não estão sendo exploradas de forma adequada ou simplesmente abandonadas por causa da contaminação com calcário, sendo este o principal contaminante indesejável pelos ceramistas do pólo teresinense. Assim, esta pesquisa tem como objetivo avaliar a potencialidade de aplicação de uma argila com calcário na produção de placas de revestimento cerâmico de queima vermelha. Para isso foram caracterizadas uma massa cerâmica usada na produção de revestimento semiporoso e uma argila contaminada com calcário. As matérias-primas foram queimadas em forno industrial separadamente e em combinação nas proporções de 25%, 50% e 75% em peso da argila adicionada a massa industrial. Foram realizados nos corpos de prova queimados ensaios tecnológicos de retração linear, absorção de água e resistência mecânica. A microestrutura foi avaliada através de análise por difração de raios X. Os resultados mostraram potencialidade da utilização da argila contaminada com calcário em massa de revestimento cerâmico.In the city of Teresina area, capital of Piauí, Brazil, there is a lot of clay deposits red burning used in the production of structural ceramics, being the main reason for installing a ceramic center in the region. But many of these deposits are not being adequately exploited or simply abandoned because of contamination with limestone, which is the main undesirable contaminant for the ceramic producers pole of Teresina. Thus, this research aims to evaluate the capability of applying some clay with limestone in the production of these plates of red ceramic burning. A ceramic body used in the production of coating semiporous and a contaminated clay with limestone were

  14. TRW Advanced Slagging Coal Combustor Utility Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    1989-01-01

    The TRW Advanced Slagging Coal Combustor Demonstration Project consists of retrofitting Orange and Rockland (O R) Utility Corporation's Lovett Plant Unit No. 3 with four (4) slagging combustors which will allow the gas/ou desip unit to fire 2.5 sulfur coal. The slogging combustor process will provide NO[sub x] and SO[sub x] emissions that meet NSPS and New York State Envirommental Standards. TRW-CBU scope of work includes the engineering, design and supply of the slogging combustors, coal and limestone feed systems and a control system for these components. During this report period, the design activities for all systems progressed to permit the release of specifications and requests for proposals. Award of contracts for long-delivery items and major equipment are being placed to meet the revised program schedule.

  15. Ball clay

    Science.gov (United States)

    Virta, Robert L.

    2010-01-01

    The article reports on the global market performance of ball clay in 2009 and presents an outlook for its 2010 performance. Several companies mined ball call in the country including Old Hickey Clay Co., Kentucky-Tennessee Clay Co., and H.C. Spinks Clay Co. Information on the decline in ball clay imports and exports is also presented.

  16. Evaluation of steel slag coarse aggregate in hot mix asphalt concrete.

    Science.gov (United States)

    Ahmedzade, Perviz; Sengoz, Burak

    2009-06-15

    This paper presents the influences of the utilization of steel slag as a coarse aggregate on the properties of hot mix asphalt. Four different asphalt mixtures containing two types of asphalt cement (AC-5; AC-10) and coarse aggregate (limestone; steel slag) were used to prepare Marshall specimens and to determine optimum bitumen content. Mechanical characteristics of all mixtures were evaluated by Marshall stability, indirect tensile stiffness modulus, creep stiffness, and indirect tensile strength tests. The electrical sensitivity of the specimens were also investigated in accordance with ASTM D257-91. It was observed that steel slag used as a coarse aggregate improved the mechanical properties of asphalt mixtures. Moreover, volume resistivity values demonstrated that the electrical conductivity of steel slag mixtures were better than that of limestone mixtures.

  17. 1st International Conference on Calcined Clays for Sustainable Concrete

    CERN Document Server

    Favier, Aurélie

    2015-01-01

    This volume focuses on research and practical issues linked to Calcined Clays for Sustainable Concrete. The main subjects are geology of clays, hydration and performance of blended systems with calcined clays, alkali activated binders, economic and environmental impacts of the use of calcined clays in cement based materials. Topics addressed in this book include the influence of processing on reactivity of calcined clays, influence of clay mineralogy on reactivity, geology of clay deposits, Portland-calcined clay systems, hydration, durability, performance, Portland-calcined clay-limestone systems, hydration, durability, performance, calcined clay-alkali systems, life cycle analysis, economics and environmental impact of use of calcined clays in cement and concrete, and field applications. This book compiles the different contributions of the 1st International Conference on Calcined Clays for Sustainable Concrete, which took place in Lausanne, Switzerland, June, 23-25, 2015.The papers present the latest  res...

  18. Exploration for limestone deposit at Onigbedu, South-Western Nigeria

    Science.gov (United States)

    Oyedele, Kayode F.; Oladele, Sunday; Emakpor, Charles A.

    2016-09-01

    The Onigbedu limestone deposit was investigated using the aeromagnetic data, resistivity soundings and borings with the aim of characterizing the limestone deposit and estimating its reserves. The subsurface structural features and depth to basement were identified with the analysis of aeromagnetic data. Twenty nine boreholes were drilled for subsurface appraisal and correlation of the limestone deposit. Eighty nine Vertical Electrical Sounding (VES) were acquired using the Schlumberger array. The results showed NE-SW trending lineaments that segmented the limestone. Depth to basement varied from 144.2 m to 1090 m. The VES results showed four to six layers indicating the topsoil (7-315 Ωm), clay (2-25 Ωm), shale (6-31 Ωm), limestone (20-223 Ωm), sandstone (>200 Ωm) and sandy materials. The VES results correlated well with the lithological unit delineated from the borehole. The overburden thickness ranged from 3.3 m to 28 m, while the limestone thickness varies between 18.1 m and 48.3 m. The limestone reserve was estimated at 1.9 × 109 t. This study concluded that the study area had vast occurrence of the limestone deposits, which would be of economic importance, if exploited.

  19. Recycling of residual IGCC slags and their benefits as degreasers in ceramics.

    Science.gov (United States)

    Iglesias Martín, I; Acosta Echeverría, A; García-Romero, E

    2013-11-15

    This work studies the evolution of IGCC slag grains within a ceramic matrix fired at different temperatures to investigate the effect of using IGCC slag as a degreaser. Pressed ceramic specimens from two clay mixtures are used in this study. The M1 mixture is composed of standard clays, whereas the M2 mixture is composed of the same clay mixture as M1 mixture but contains 15% by weight IGCC slag. The amount of IGCC slag added coincides with the amount of slag typically used as a degreaser in the ceramic industry. Specimens are fired at 950 °C, 1000 °C, 1050 °C, 1100 °C and 1150 °C. The mineralogical composition and the IGCC slag grain shape within the ceramic matrix are determined by X-ray diffraction, polarized light microscopy and scanning electron microscopy. The results reveal that the surface of the slag grains is welded to the ceramic matrix while the quartz grains are separated, which causes increased water absorption and reduces the mechanical strength. IGCC slag, however, reduces water absorption. This behaviour is due to the softening temperature of the slag. This property is quite important from an industrial viewpoint because IGCC slag can serve as an alternative to traditional degreasing agents in the ceramic building industry. Additionally, using IGCC slag allows for the transformation of waste into a secondary raw material, thereby avoiding disposal at landfills; moreover, these industrial wastes are made inert and improve the properties of ceramics.

  20. Rapid Dissolution of Quicklime into Molten Slag by Internally Formed Gas

    Science.gov (United States)

    Maruoka, Nobuhiro; Nogami, Hiroshi

    2017-02-01

    In steelmaking process, quicklime is used to produce CaO-based slag. Although rapid dissolution of quicklime is required for high-efficiency refining, it is known that the rate decreases when dicalcium silicate (C2S) layer forms around the quicklime by reacting with slag. The equation that driving force is the difference of CaO content between in slag and a liquid phase of slag saturated by C2S has been often used for estimating the dissolution rate of lime, in which this saturated value is thermodynamically determined. The authors, however, revealed that the quicklime used in actual operation showed much faster dissolving rate than that of completely calcined lime that is covered by C2S layer during dissolution into slag. This was caused by a gas formation due to a thermal decomposition of residual limestone existed in quicklime. In this study, the dissolution rate of quicklime with the gas formation is quantitatively investigated.

  1. Laboratory Investigation of Fatigue Characteristics of Asphalt Mixtures with Steel Slag Aggregates

    Directory of Open Access Journals (Sweden)

    Hassan Ziari

    2015-01-01

    Full Text Available There are many steel-manufacturing factories in Iran. All of their byproducts, steel slag, are dumped randomly in open areas, causing many environmentally hazardous problems. This research is intended to study the effectiveness of using steel slag aggregate (SSA in improving the engineering properties, especially fatigue life of Asphalt Concrete (AC produced with steel slag. The research started by evaluating the physical properties of the steel slag aggregate. Then the 13 types of mixes which contain steel slag in portion of fine aggregates or in portion of coarse aggregates or in all portions of aggregates were tested. The effectiveness of the SSA was judged by the improvement in Marshall stability, indirect tensile strength, resilient modulus, and fatigue life of the AC samples. It was found that replacing the 50% of the limestone coarse or fine aggregate by SSA improved the mechanical properties of the AC mixes.

  2. Clay Play

    Science.gov (United States)

    Rogers, Liz; Steffan, Dana

    2009-01-01

    This article describes how to use clay as a potential material for young children to explore. As teachers, the authors find that their dialogue about the potential of clay as a learning medium raises many questions: (1) What makes clay so enticing? (2) Why are teachers noticing different play and conversation around the clay table as compared to…

  3. Ball clay

    Science.gov (United States)

    Virta, R.L.

    2011-01-01

    The article discusses the latest developments in the global ball clay mining industry, particularly in the U.S., as of June 2011. It cites several firms that are involved in ball clay mining in the U.S., including HC Spins Clay Co. Inc., the Imerys Group and Old Hickory Clay Co. Among the products made from ball clay are ceramic tiles, sanitaryware, as well as fillers, extenders and binders.

  4. 锰渣陶土复合材料制备外墙保温轻质瓷砖及力学性能分析研究%Use of manganese slag and clay composite material in exterior wall lightweight thermal insulation tile and its mechanical properties

    Institute of Scientific and Technical Information of China (English)

    梁峙; 庄旭; 顾烨; 倪振威; 梁骁; 马捷; 肖扬; 王君; 王广彬

    2015-01-01

    以锰渣、陶土、碳化硅、耐火纤维为主要原料,通过经混合、成型、干燥和烧成等工艺制得锰渣陶土外墙保温轻质瓷砖,实验通过测定不同的锰渣含量和烧结温度,对样品的抗折强度、吸水率进行了分析,通过实验数据表明:锰渣粉含量20%、在氮气环境下烧结、烧结温度850℃,产品吸水率、抗折强度达到最佳效果,通过XRD分析,产品含有大量的锰元素,表明此次试验在高温下保留了锰的原有形态。试验样品具有耐高温、高强度、抗腐蚀性等一系列优良性能。%The exterior wall lightweight thermal insulation tile is prepared by manganese slag, clay, silicon carbide, and refractory fiber as main raw materials. The effect of manganese slag content and firing temperature on the bending strength and water absorption of samples is analyzed. The test show that the samples characterize high temperature resistance, high bending strength, corrosion resistance and other good properties.

  5. Direct Sulfation of Limestone

    DEFF Research Database (Denmark)

    Hu, Guilin; Dam-Johansen, Kim; Wedel, Stig

    2007-01-01

    The direct sulfation of limestone was studied in a laboratory fixed-bed reactor. It is found that the direct sulfation of limestone involves nucleation and crystal grain growth of the solid product (anhydrite). At 823 K and at low-conversions (less than about 0.5 %), the influences of SO2, O-2...... and CO2 on the direct sulfation of limestone corresponds to apparent reaction orders of about 0.2, 0.2 and -0.5, respectively. Water is observed to promote the sulfation reaction and increase the apparent reaction orders of SO2 and O-2. The influence of O-2 at high O-2 concentrations (> about 15...... %) becomes negligible. In the temperature interval from 723 K to 973 K, an apparent activation energy of about 104 kJ/mol is observed for the direct sulfation of limestone. At low temperatures and low conversions, the sulfation process is most likely under mixed control by chemical reaction and solid...

  6. Clay Houses

    Science.gov (United States)

    Pedro, Cathy

    2011-01-01

    In this article, the author describes a project designed for fourth-graders that involves making clay relief sculptures of houses. Knowing the clay houses will become a family heirloom makes this lesson even more worth the time. It takes three classes to plan and form the clay, and another two to underglaze and glaze the final products.

  7. EFFECT OF USING STEEL SLAG AGGREGATE ON MECHANICAL PROPERTIES OF CONCRETE

    Directory of Open Access Journals (Sweden)

    Sultan A. Tarawneh

    2014-01-01

    Full Text Available This study presents an evaluation of the physical and mechanical properties and characteristics of steel slag aggregate concrete in comparison with the typical crushed limestone stone aggregate concrete. Hardened concrete consist of more than 70% aggregate due to the high demand in building construction and the increase of the amount of disposed waste material, suppliers and researchers are exploring the use of alternative materials which could preserve natural sources and save the environment. In this study, steel slag was used as an aggregate replacement in conventional concrete mixes. Steel slag which is mainly consists of calcium carbonate is produced as a by-product during the oxidation process in steel industry. Steel slag was selected due to its characteristics, which are almost similar to conventional aggregates and the fact that it is easily obtainable as a by-product of the steel industry. As a result, utilization of steel slag will save natural resources and clean environment. Furthermore, results have shown that slag aggregate has better abrasion factor and impact value than conventional aggregate. Thorough investigation of the results have indicated that the amount of increase in compressive strength at age of 7 days are much more than that of age 28 days for all types of aggregate replacement. This indicates that the added slag could work as accelerator at early age while at 28 days age, the effect is reduced. The fine slag replacement scores the highest effect.

  8. Strength of Limestone-based Non-calcined Cement and its Properties

    Institute of Scientific and Technical Information of China (English)

    LIN Zongshou; ZHAO Qian

    2009-01-01

    A new type of cement was prepared with ground limestone powder,blastfurnace slag,steel slag and gypsum without calcination.The fraction of ground limestone powder in the cement was as high as 40 wt%-60 wt%without Portland clinker.All of its physical properties can meet the requirements of masonry cement standards.The impact of limestone content on physical properties of the cement and determined its impact on law was investigated.The steel slag can excit the aquation activity of this cement effectively,and the influence of its quantity on the strength of the materials was studied,which shows that the optimum quantity of mixing is 10%.By way of changing the different content of the lime stone by quartzy sample,the law of the compression strength and the PH value was determined,confirming that the lime stone can promote the early aquation of the slag and improve the early strength.The main hydration product of this cement is calcium aluminate hydrate, ettringite and calcium silicate hydrate,as indicated by XRD and SEM analysis.

  9. performance of steel slag performance of steel slag as fine ...

    African Journals Online (AJOL)

    eobe

    reduced from 0.62 to 0.50 as slag proportion increased from 0% to 100% at slump. 0.62 to 0.50 as slag ... Nigerian Journal of Technology (NIJOTECH). Vol. 34 No. 3, July ... scrap metals and hundreds of tonnes of steel slag are produced every ...

  10. Carbon and Oxygen Isotope Ratios in Rona Limestone, Romania

    Directory of Open Access Journals (Sweden)

    Stela Cuna

    2001-04-01

    Full Text Available The carbon and oxygen isotopic compositions of limestones provide criteria for the evaluation of the depositional environment. For Jurassic and younger samples, the best discrimination between marine and fresh-water limestones is given by Z parameter, calculated as a linear correlation between δ13C and δ18O (‰ PDB. Rona Limestone (Upper Paleocene - Lower Eocene, outcropping on a small area in NW Transylvania (Meseş area is a local lacustrine facies. There, it divides Jibou Formation into the Lower Red Member and the Upper Variegated Member, respectively. Recently, a sequence containing a marine nannoplankton assemblage was identified in the base of Rona deposits. The main goal of our study was to characterize, based on the isotopic record, the primary environment of formation of the deposit, as well as that in which some diagenetic processes (the formation of dolomite and of green clay around the siliceous chert nodules took place. Ten samples representing limestones, dolomitic limestone, marls and the green carbonate-rich clay were studied from petrographical and mineralogical points of view, and the carbon and oxygen isotopic ratios from the carbonate (calcite component were measured. In conclusion, it was found that the procedure of extraction of CO2 we used enabled the discrimination between the isotopic prints of calcite vs. dolomite. This pleads for considering our results as a primary isotopic pattern in the bulk rock. The oxygen and carbon isotope data indicate a fresh-water depositional environment with Z<120. The δ13C mean value (-4.96 ‰ PDB is, generally, representative for fresh-water carbonates of the Tertiary period. The same environment characterized also the formation of carbonates within the green clay.

  11. Characterization of environmentally-friendly alkali activated slag cements and ancient building materials

    Science.gov (United States)

    Sakulich, Aaron Richard

    Alternative cement technologies are an area of increasing interest due to growing environmental concerns and the relatively large carbon footprint of the cement industry. Many new cements have been developed, but one of the most promising is that made from granulated, ground blast furnace slag activated by a high-pH solution. Another is related to the discovery that some of the pyramid limestone blocks may have been cast using a combination of diatomaceous earth activated by lime which provides the high pH needed to dissolve the diatomaceous earth and bind the limestone aggregate together. The emphasis of this thesis is not on the latter---which was explored elsewhere---but on the results supplying further evidence that some of the pyramid blocks were indeed reconstituted limestone. The goal of this work is to chemically and mechanically characterize both alkali-activated slag cements as well as a number of historic materials, which may be ancient analogues to cement. Alkali activated slag cements were produced with a number of additives; concretes were made with the addition of a fine limestone aggregate. These materials were characterized mechanically and by XRD, FTIR, SEM, and TGA. Samples from several Egyptian pyramids, an 'ancient floor' in Colorado, and the 'Bosnian Pyramids' were investigated. In the cements, it has been unequivocally shown that C-S-H, the same binding phase that is produced in ordinary portland cement, has been produced, as well as a variety of mineral side products. Significant recarbonation occurs during the first 20 months, but only for the Na2CO3-activated formulae. Radiocarbon dating proves that the 'Bosnian Pyramids' and 'ancient floors' are not made from any type of recarbonated lime; however, Egyptian pyramid limestones were finite, thus suggesting that they are of a synthetic nature. XRD and FTIR results were inconclusive, while TGA results indicate the limestones are identical to naturally occurring limestones, and SEM

  12. A Blended Cement Containing Blast Furnace Slag and Phosphorous Slag

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Blended cement containing blast furnace slag(BFS) and phosphorous slag(PS) is a new kind of cement.The total content of blended materials could increase if two additives were used. Using the same admixtures, the properties of the blended cement with 70% additives could reach the standard of 525-grade slag cement according to GB.The strength of cement with 80% additives could reach the standard of 425-grade slag cement.The tests of strength, pore structure,hydration products,inhibiting alkali-aggregate reaction, resistance to sulfate corrosion of BFS-PSC were performed.

  13. PHOSPHORUS REMOVAL USING STEEL SLAG

    Institute of Scientific and Technical Information of China (English)

    Y.Z. Lan; S. Zhang; J.K. Wang; R. W. Smith

    2006-01-01

    Steel slag is a byproduct produced in large amounts in the steel-making process. It is an important resource that can be effectively utilized. An experiment was described in which steel slag was tested as an adsorbent for the removal of phosphorus from waste water. Phosphorus removal depended on the amount of steel slag added, the pH value, the contact time, and the initial concentration. Under laboratory conditions when the added slag was 7.5g/L, the contact time 2h, and the pH value was equivalent to 6.5, over 99% of the phosphorus was removed; the experimental data on steel slag adsorption of phosphorus in the water fitted the Freundlich isotherm model. Steel slag was found to be very effective in adsorbing phosphorus.

  14. Hydraulic properties of ladle slags

    Directory of Open Access Journals (Sweden)

    J. Vlček

    2016-07-01

    Full Text Available The article presents results of examining of hydraulic properties of ladle slags formed during production of steel. The studied ladle slags were subjected to different cooling mode from the molten state. Based on the ability of the slag react with the water was assessed their hydraulic activity. The hydraulic properties are caused by the presence of minerals dicalcium silicate, tricalcium aluminate, mayenite, brownmillerite and dicalcium ferite. The emergence of required hydrating phases in the ladle slags is conditioned by a sufficient CaO content and their cooling rate. The contact the slag with water during processing and their ageing has a negative effect. The experiment has shown that the phase transformation of the mineral dicalcium silicate which occurs during cooling of the ladle slags cause their volume instability.

  15. Basic Oxygen Furnace Slag as a Liming Agent for Paddy and Upland Field Soils

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Choong Il [Pohang Research Institute of Industrial Science and Technology, Pohang(Korea)

    1998-03-31

    Basic oxygen furnace (BOF) slag, a by-product of the iron and steelmaking industry produced in large quantities in Korea, poses a substantial disposal challenge. The BOF slag used in this study was 1/3 CaCO{sub 3} in total neutralizing power and application of 7-8 Mgha{sup -1} was needed to bring soil pH to 6.5 from pH 5.0-5.5 in silty clay or clay loam soil contained about 10% organic matter. A field assay was conducted to study whether BOF slag could be used as a dolomitic liming agent for agricultural soils. Four slag rates (0, 4, 8, 12 Mgha{sup -1})were investigated for their effect on soil properties, mineral concentrations in leaf tissues of rice and soybean, and yield of the crops. Slag application at 8 Mgha{sup -1} rate in paddy field increased pH, Ca, Mg, P, Si and Fe content in soil and rice yield by 4.3-14.2% depending on the soil type. In upland field the 8 Mgha{sup -1} rate increased pH, Ca and Fe content in soil and soybean yield by 36.6%. Thus, BOF slag appears to be a useful liming material for correcting soil acidity on both paddy and upland field soils and for increasing Ca, Mg, P, Si, and Fe concentration in plants. (author). 27 refs., 7 tabs.

  16. NONEQUILIBRIUM SULFUR CAPTURE & RETENTION IN AN AIR COOLED SLAGGING COAL COMBUSTOR

    Energy Technology Data Exchange (ETDEWEB)

    Bert Zauderer

    2003-04-21

    Calcium oxide injected in a slagging combustor reacts with the sulfur from coal combustion to form sulfur-bearing particles. The reacted particles impact and melt in the liquid slag layer on the combustor wall by the centrifugal force of the swirling combustion gases. Due to the low solubility of sulfur in slag, it must be rapidly drained from the combustor to limit sulfur gas re-evolution. Prior analyses and laboratory scale data indicated that for Coal Tech's 20 MMBtu/hour, air-cooled, slagging coal combustor slag mass flow rates in excess of 400 lb/hr should limit sulfur re-evolution. The objective of this 42-month project was to validate this sulfur-in-slag model in a group of combustor tests. A total of 36 days of testing on the combustor were completed during the period of performance of this project. This was more that double the 16 test days that were required in the original work statement. The extra tests were made possible by cost saving innovations that were made in the operation of the combustor test facility and in additional investment of Coal Tech resources in the test effort. The original project plan called for two groups of tests. The first group of tests involved the injection of calcium sulfate particles in the form of gypsum or plaster of Paris with the coal into the 20 MMBtu/hour-combustor. The second group of tests consisted of the entire two-step process, in which lime or limestone is co-injected with coal and reacts with the sulfur gas released during combustion to form calcium sulfate particles that impact and dissolve in the slag layer. Since this sulfur capture process has been validated in numerous prior tests in this combustor, the primary effort in the present project was on achieving the high slag flow rates needed to retain the sulfur in the slag.

  17. Refractories Utilizability for Slagging Gasifiers

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Slagging coal gasification process became a highlight of coal chemical industry in China during the last decade. Refractory lining's life of slagging gasifiers is one of the most critical factors for a cost -effective operation. The paper introduces current status of coal gasification in China, lining structure of slagging gasifiers and performance of refractory lining. It also summarizes the major factors impacting on refractory wear in slagging coal gasifiers in four Chinese chemical plants, based on ten years of industrial experience. The utilizability is discussed in terms of cost -effectiveness of high chromia refractories and possibility of the alternatives.

  18. Recycling of Malaysia's electric arc furnace (EAF) slag waste into heavy-duty green ceramic tile.

    Science.gov (United States)

    Teo, Pao-Ter; Anasyida, Abu Seman; Basu, Projjal; Nurulakmal, Mohd Sharif

    2014-12-01

    Recently, various solid wastes from industry such as glass waste, fly ash, sewage sludge and slag have been recycled into various value-added products such as ceramic tile. The conventional solutions of dumping the wastes in landfills or incineration, including in Malaysia are getting obsolete as the annual huge amount of the solid wastes would boost-up disposal cost and may cause permanent damage to the flora and fauna. This recent waste recycling approach is much better and greener as it can resolve problems associated with over-limit storage of industrial wastes and reduce exploration of natural resources for ceramic tile to continuously sustain the nature. Therefore, in this project, an attempt was made to recycle electric arc furnace (EAF) slag waste, obtained from Malaysia's steel making industry, into ceramic tile via conventional powder compaction method. The research work was divided into two stages. The first stage was to evaluate the suitability of EAF slag in ceramic tile by varying weight percentage of EAF slag (40 wt.%, 50 wt.% and 60 wt.%) and ball clay (40 wt.%, 50 wt.% and 60 wt.%), with no addition of silica and potash feldspar. In the second stage, the weight percentage of EAF slag was fixed at 40 wt.% and the percentage of ball clay (30 wt.% and 40 wt.%), feldspar (10 wt.% and 20 wt.%) and silica (10 wt.% and 20 wt.%) added was varied accordingly. Results obtained show that as weight percentage of EAF slag increased up to 60 wt.%, the percentage of apparent porosity and water absorption also rose, with a reduction in tile flexural strength and increased porosity. On the other hand, limiting the weight percentage of EAF slag to 40 wt.% while increasing the weight percentage of ball clay led to a higher total percentage of anorthite and wollastonite minerals, resulting in higher flexural strength. It was found that introduction of silica and feldspar further improved the flexural strength due to optimization of densification process. The highest

  19. 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, whi

  20. Performance of portland limestone cements: Cements designed to be more sustainable that include up to 15% limestone addition

    Science.gov (United States)

    Barrett, Timothy J.

    where the limestone was blended (i.e., not interground) as needed, enabling variation of the size of the limestone particles. In addition, one of the commercially produced OPCs and PLCs were used with fly ash. A series of standardized tests were run to assess the physical effects of intergrinding limestone in portland cement, the effect of limestone presence and method of inclusion on the hydration reaction, and the associated mechanical and transport properties of concretes made with these limestone cements. The second phase of the study used a commercially produced OPC, a PLC, and a PLC-slag all made from the same parent clinker to quantify the early age shrinkage and cracking potential. The study presents a series of tests that quantify the fundamental origins of shrinkage in cementitious materials to elucidate the differences between PLC and OPC. The bulk shrinkage of these systems is then quantified under free and restrained conditions to provide an assessment of the susceptibility for cracking in portland limestone cements. The results of the first phase of this thesis showed that in general the PLC and OPC systems have similar hydration, set, and mechanical performance. Transport properties in this study show behavior that is +/- 30% of the conventional OPC system depending on the system. Literature has shown similar freeze-thaw resistance when these materials are used in properly air entrained mixtures, and the results for PLC systems with fly ash show added performance. Based on these results it appears that PLC that meets ASTM C595/AASHTO M234 should be able to be used interchangeably with OPC, while it should also be noted that the investigation of the influence of salts and sulfates on PLCs is still ongoing and should be monitored. The results of the second phase of this thesis showed that while the PLCs are finer, this comes primarily by reducing the very large particles (clinker particles greater than 30 microns) using advanced separator technology and

  1. 21 CFR 184.1409 - Ground limestone.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ground limestone. 184.1409 Section 184.1409 Food... Specific Substances Affirmed as GRAS § 184.1409 Ground limestone. (a) Ground limestone consists essentially... classifying of naturally occurring limestone. (b) The ingredient meets the specifications of the...

  2. Application of aluminum slag incorporated in lightweigh aggregate; Utilizacao da escoria de aluminio na fabricacao de argila expandida

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Elisa Akiko Nakano

    2006-07-01

    The use of industrial waste materials as additives in the manufacture of ceramic product has been attracting a growing interest in the last few years and is becoming common practice. The main purpose of this work is to evaluate the possibility of incorporation of aluminum slag into clay materials. Expansive clays are obtained from a pyro plastic expansion, and are usually employed like lightweight aggregate in structural concrete as ornamental garden products. The characterization of the aluminum slag and clay materials was carried out by Xray fluorescence spectrometry, Xray diffraction, granulometry, differential thermal analysis, thermal gravimetry (DTA and TG) and scanning electron microscopy. The studied compositions contained 5, 10, 15 and 20 weight % of aluminum slag into clay mass. The linear expansion, mass variation, apparent specific mass and water absorption of all compositions were determined. Leaching and solubilization experiments were also performed. The main results show the viability of using up to 5 wt% aluminum slag for producing expansive clays with characteristics within the accepted standards. (author)

  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. 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.

  5. River water quality in weathered limestone: A case study in upper Mahanadi basin, India

    Indian Academy of Sciences (India)

    B K Panigrahy; B C Raymahashay

    2005-10-01

    Stromatolitic limestone and calcareous shale belonging to Chattisgarh Supergroup of Proterozoic age dominate the upper part of the Mahanadi river basin.X-ray diffractogram (XRD)of limestone rocks show presence of a significant amount of calcite,dolomite and ankerite.Shales of various colours contain calcite and dolomite.It is observed that congruent dissolution of carbonate minerals in the Charmuria pure limestone has given rise to a typical karst topography.On the other hand, limestones are also seen to support red and black soil pro files.This indicates that the limestone bedrock undergoes a parallel incongruent weathering,which leaves a residue of decomposed rock. The XRD analyses reveal that the limestone soils thus formed contain an assemblage of quartz,clays and Fe-oxides.It is likely that the silicate component trapped during deposition of the stromatolitic limestone weathers incongruently resulting in diverse soil profiles.Carbonate and silicate mineral weathering schemes have been worked out to explain the soil formation,fixation of Al in clay minerals, and Fe in goethite.The water quality parameters such as Ca, Mg and HCO3 in the river water suggest under saturation with respect to calcite and dolomite.The mineral stability diagrams indicate that kaolinite and Ca-smectite are stable in the river water environment,hence they occur in suspended sediments and soils.The dominant influence of carbonate weathering on the water quality is observed even in the downstream part of the river outside the limestone terrain.

  6. Understanding Slag Freeze Linings

    Science.gov (United States)

    Fallah-Mehrjardi, Ata; Hayes, Peter C.; Jak, Evgueni

    2014-09-01

    Slag freeze linings, the formation of protective deposit layers on the inner walls of furnaces and reactors, are increasingly used in industrial pyrometallurgical processes to ensure that furnace integrity is maintained in these aggressive, high-temperature environments. Most previous studies of freeze-linings have analyzed the formation of slag deposits based solely on heat transfer considerations. These thermal models have assumed that the interface between the stationary frozen layer and the agitated molten bath at steady-state deposit thickness consists of the primary phase, which stays in contact with the bulk liquid at the liquidus temperature. Recent experimental studies, however, have clearly demonstrated that the temperature of the deposit/liquid bath interface can be lower than the liquidus temperature of the bulk liquid. A conceptual framework has been proposed to explain the observations and the factors influencing the microstructure and the temperature of the interface at steady-state conditions. The observations are consistent with a dynamic steady state that is a balance between (I) the rate of nucleation and growth of solids on detached crystals in a subliquidus layer as this fluid material moves toward the stagnant deposit interface and (II) the dissolution of these detached crystals as they are transported away from the interface by turbulent eddies. It is argued that the assumption that the interface temperature is the liquidus of the bulk material represents only a limiting condition, and that the interface temperature can be between T liquidus and T solidus depending on the process conditions and bath chemistry. These findings have implications for the modeling approach and boundary conditions required to accurately describe these systems. They also indicate the opportunity to integrate considerations of heat and mass flows with the selection of melt chemistries in the design of future high temperature industrial reactors.

  7. Stratigraphy and sedimentology of the Upper Cretaceous (Campanian) Anacacho Limestone, Texas, USA

    Science.gov (United States)

    Swezey, C.S.; Sullivan, E.C.

    2004-01-01

    The Upper Cretaceous Anacacho Limestone is exposed in outcrops between the cities of San Antonio and Del Rio, Texas. A detailed study of four outcrops (Blanco Creek section, Sabinal River section, Seco Creek section, Hondo Creek section) shows that the Anacacho Limestone rests on the Upson Clay (which contains fauna of early Campanian age) and is overlain by the Corsicana Marl (which contains fauna of early Maastrichtian age). An unconformity within the Anacacho Limestone is used herein to separate the limestone into a lower member and an upper member. The lower Anacacho member contains fauna of early Campanian age, whereas the upper Anacacho member contains fauna of middle Campanian age. The lower Anacacho member consists predominantly of wackestones to packstones, which are overlain by packstones to grainstones capped by the unconformity. This unconformity is interpreted as a marine flooding surface, delineating a transition from carbonate grainstones deposited in shallow water (<30 m depth) to a chalk deposited in deeper water. Above the unconformity, the upper Anacacho member is characterized by a chalk, overlain by wackestones and packstones. The uppermost section of the Anacacho Limestone consists of packstones and grainstones with abundant and diverse fossils. Most of the Anacacho Limestone developed in relatively shallow water (<50 m depth) leeward of a large carbonate build-up (possibly a rudistid reef) that now comprises the Anacacho Mountains. The environment, however, was open to marine water throughout deposition of the Anacacho Limestone. ?? 2004 Elsevier Ltd. All rights reserved.

  8. Rheological Characterization of Warm-Modified Asphalt Mastics Containing Electric Arc Furnace Steel Slags

    Directory of Open Access Journals (Sweden)

    M. Pasetto

    2016-01-01

    Full Text Available The environmental sustainability of road materials and technologies plays a key role in pavement engineering. In this sense, the use of Warm Mix Asphalt (WMA, that is, a modified asphalt concrete that can be produced and applied at lower temperature, is considered an effective solution leading to environmental and operational benefits. The environmental sustainability of WMA can be further enhanced with the inclusion of steel slag in partial substitution of natural aggregates. Nevertheless, such innovative material applied at lower temperatures containing warm additives and steel slag should be able to guarantee at least the same performance of traditional hot mix asphalts, thus assuring acceptable mechanical properties and durability. Therefore, the purpose of this study is to investigate the rheological behaviour of bituminous mastics obtained combining a warm-modified binder and a filler (material passing to 0.063 mm coming from electric arc furnace steel slag. To evaluate the influence of both warm additive and steel slag, a plain binder and limestone filler were also used for comparison purposes. Complex modulus and permanent deformation resistance of bitumens and mastics were assessed using a dynamic shear rheometer. Experimental results showed that steel slag warm mastics assure enhanced performance demonstrating promising applicability.

  9. Geochemistry, environmental and provenance study of the Middle Miocene Leitha limestones (Central Paratethys

    Directory of Open Access Journals (Sweden)

    Ali Ahmed

    2017-06-01

    Full Text Available Mineralogical, major, minor, REE and trace element analyses of rock samples were performed on Middle Miocene limestones (Leitha limestones, Badenian collected from four localities from Austria (Mannersdorf, Wöllersdorf, Kummer and Rosenberg quarries and the Fertőrákos quarry in Hungary. Impure to pure limestones (i.e. limited by Al2O3 contents above or below 0.43 wt. % were tested to evaluate the applicability of various geochemical proxies and indices in regard to provenance and palaeoenvironmental interpretations. Pure and impure limestones from Mannersdorf and Wöllersdorf (southern Vienna Basin show signs of detrital input (REEs = 27.6 ± 9.8 ppm, Ce anomaly = 0.95 ± 0.1 and the presence of quartz, muscovite and clay minerals in impure limestones and diagenetic influence (low contents of, e.g., Sr = 221 ± 49 ppm, Na is not detected, Ba = 15.6 ± 8.8 ppm in pure limestones. Thus, in both limestones the reconstruction of original sedimentary palaeoenvironments by geochemistry is hampered. The Kummer and Fertőrákos (Eisenstadt–Sopron Basin comprise pure limestones (e.g., averages Sr = 571 ± 139 ppm, Na = 213 ± 56 ppm, Ba = 21 ± 4 ppm, REEs = 16 ± 3 ppm and Ce anomaly = 0.62 ± 0.05 and composed predominantly of calcite exhibiting negligible diagenesis. Deposition under a shallow-water, well oxygenated to intermittent dysoxic marine environment can be reconstructed. Pure to impure limestones at Rosenberg–Retznei (Styrian Basin are affected to some extent by detrital input and volcano-siliciclastic admixture. The Leitha limestones at Rosenberg have the least diagenetic influence among the studied localities (i.e. averages Sr = 1271 ± 261 ppm, Na = 315 ± 195 ppm, Ba = 32 ± 15 ppm, REEs = 9.8 ± 4.2 ppm and Ce anomaly = 0.77 ± 0.1 and consist of calcite, minor dolomite and quartz. The siliciclastic sources are characterized by immobile elemental ratios (i.e. La/Sc and Th/Co which apply not only for the siliciclastics, but also

  10. Salt decay of Morley limestone

    NARCIS (Netherlands)

    Nijland, T.G.; Van Hees, R.P.J.

    2009-01-01

    Salt weathering is one of the main causes of decay of natural stone, and by consequence a major problem to the conservation of cultural heritage. In the present case, the performance of Morley limestone from the Département Meuse, France, as a replacement stone under saltloaded conditions is evaluat

  11. Paleozoic Hydrocarbon-Seep Limestones

    Science.gov (United States)

    Peckmann, J.

    2007-12-01

    To date, five Paleozoic hydrocarbon-seep limestones have been recognized based on carbonate fabrics, associated fauna, and stable carbon isotopes. These are the Middle Devonian Hollard Mound from the Antiatlas of Morocco [1], Late Devonian limestone lenses with the dimerelloid brachiopod Dzieduszyckia from the Western Meseta of Morocco [2], Middle Mississippian limestones with the dimerelloid brachiopod Ibergirhynchia from the Harz Mountains of Germany [3], Early Pennsylvanian limestones from the Tantes Mound in the High Pyrenees of France [4], and Late Pennsylvanian limestone lenses from the Ganigobis Shale Member of southern Namibia [5]. Among these examples, the composition of seepage fluids varied substantially as inferred from delta C-13 values of early diagenetic carbonate phases. Delta C-13 values as low as -50 per mil from the Tantes Mound and -51 per mil from the Ganigobis limestones reveal seepage of biogenic methane, whereas values of -12 per mil from limestones with Dzieduszyckia associated with abundant pyrobitumen agree with oil seepage. Intermediate delta C-13 values of carbonate cements from the Hollard Mound and Ibergirhynchia deposits probably reflect seepage of thermogenic methane. It is presently very difficult to assess the faunal evolution at seeps in the Paleozoic based on the limited number of examples. Two of the known seeps were typified by extremely abundant rhynchonellide brachiopods of the superfamily Dimerelloidea. Bivalve mollusks and tubeworms were abundant at two of the known Paleozoic seep sites; one was dominated by bivalve mollusks (Hollard Mound, Middle Devonian), another was dominated by tubeworms (Ganigobis Shale Member, Late Pennsylvanian). The tubeworms from these two deposits are interpreted to represent vestimentiferan worms, based on studies of the taphonomy of modern vestimentiferans. However, this interpretation is in conflict with the estimated evolutionary age of vestimentiferans based on molecular clock methods

  12. Evaluation on chemical stability of lead blast furnace (LBF) and imperial smelting furnace (ISF) slags.

    Science.gov (United States)

    Yin, Nang-Htay; Sivry, Yann; Guyot, François; Lens, Piet N L; van Hullebusch, Eric D

    2016-09-15

    The leaching behavior of Pb and Zn from lead blast furnace (LBF) and imperial smelting furnace (ISF) slags sampled in the North of France was studied as a function of pHs and under two atmospheres (open air and nitrogen). The leaching of major elements from the slags was monitored as a function of pH (4, 5.5, 7, 8.5 and 10) under both atmospheres for different slag-water interaction times (1 day and 9 days). The leaching results were coupled with a geochemical model; Visual MINTEQ version 3.0, and a detailed morphological and mineralogical analysis was performed on the leached slags by scanning and transmission electron microscopy (SEM and TEM). Significant amounts of Ca, Fe and Zn were released under acidic conditions (pH 4) with a decrease towards the neutral to alkaline conditions (pH 7 and 10) for both LBF and ISF slags. On the other hand, Fe leachability was limited at neutral to alkaline pH for both slags. The concentrations of all elements increased gradually after 216 h compared to initial 24 h of leaching period. The presence of oxygen under open-air atmosphere not only enhanced oxidative weathering but also encouraged formation of secondary oxide and carbonate phases. Formation of carbonates and clay minerals was suggested by Visual MINTEQ which was further confirmed by SEM & TEM. The hydration and partial dissolution of hardystonite, as well as the destabilization of amorphous glassy matrix mainly contributed to the release of major elements, whereas the spinel related oxides were resistant against pH changes and atmospheres within the time frame concerned for both LBF and ISF slags. The total amount of Pb leached out at pH 7 under both atmospheres suggested that both LBF and ISF slags are prone to weathering even at neutral environmental conditions.

  13. Limestone valib eetilisi firmasid / Virge Lahe

    Index Scriptorium Estoniae

    Lahe, Virge

    2008-01-01

    Endised Hansapanga investeerimisfondide analüütikud hakkavad läbi Limestone fondide pakkuma sotsiaalselt vastutustundlikku investeerimist (Socially Responsible Investing). Kommenteerivad Art Lukas ja Silver Vohu. Vt. samas: Limestone Investment Management AS

  14. Engineering Geology of Limestone in Malaysia

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper provides an overview of the engineering geology of limestone. Limestone is of rather wide occurrence in Malaysia. It is interesting in view of the unique landforms and karstic features that are encountered in limestone terrains, e.g. steep, subvertical limestone cliffs rising abruptly and majestically above the ground surface and highly variable and pinnacled subterranean limestone bedrock. The karstic features and associated engineering geological problems of both the limestone hills and the bedrock are discussed in the paper. Rockfalls, sinkholes, cavities, etc. are some of the common engineering geological problems associated with limestone terrains. Some local case studies are provided as illustrations. Finally the rock mechanical properties of limestone is discussed at the end of the paper.``

  15. Limestone valib eetilisi firmasid / Virge Lahe

    Index Scriptorium Estoniae

    Lahe, Virge

    2008-01-01

    Endised Hansapanga investeerimisfondide analüütikud hakkavad läbi Limestone fondide pakkuma sotsiaalselt vastutustundlikku investeerimist (Socially Responsible Investing). Kommenteerivad Art Lukas ja Silver Vohu. Vt. samas: Limestone Investment Management AS

  16. Structural studies in limestone sulfidation

    Energy Technology Data Exchange (ETDEWEB)

    Fenouil, Laurent A. [Univ. of California, Berkeley, CA (United States)

    1993-05-01

    This study investigates the sulfidation of limestone at high temperatures (700--900°C) as the first step in the design of a High-Temperature Coal-Gas Clean-Up system using millimeter-size limestone particles. Several workers have found that the rate of this reaction significantly decreases after an initial 10 to 15% conversion of CaCO3 to CaS. The present work attempts to explain this feature. It is first established that millimeter-size limestone particles do not sinter at temperatures up to the CaCO3 calcination point (899°C at 1.03 bar CO2} partial pressure). It is then shown that CaS sinters rapidly at 750 to 900°C if CO2 is present in the gas phase. Scanning Electron Microscope (SEM) photographs and Electron Dispersive Spectroscopy (EDS) data reveal that the CaS product layer sinters and forms a quasi-impermeable coating around the CaCO3 grains that greatly hinders more H2S from reaching the still unreacted parts of the stone. Moreover, most of the pores initially present within the limestone structure begin to disappear or, at least, are significantly reduced in size. From then on, subsequent conversion is limited by diffusion of H2S through the CaS layer, possibly by S2- ionic diffusion. The kinetics is then adequately described by a shrinking-core model, in which a sharp front of completely converted limestone is assumed to progress toward the center of the pellet. Finally, experimental evidence and computer simulations using simple sintering models suggest that the CaS sintering, responsible for the sharp decrease in the sulfidation rate, is surface-diffusion controlled.

  17. Overview of Steel Slag Application and Utilization

    Directory of Open Access Journals (Sweden)

    Lim J.W.

    2016-01-01

    Full Text Available Significant quantities of steel slag are generated as waste material or byproduct every day from steel industries. Slag is produced from different types of furnaces with different operating conditions. Slag contains Ferrous Oxide, Calcium Oxide, Silica etc. Physical and chemical properties of slag are affected by different methods of slag solidification such as air cooled, steam, and injection of additives. Several material characterization methods, such as X-ray Diffraction (XRD, Scanned Electron Microscopy (SEM and Inductive Coupled Plasma (ICP-OES are used to determine elemental composition in the steel slag. Therefore, slags can become one of the promising materials in various applications such as in transportation industry, construction, cement production, waste water and water treatment. The various applications of steel slag indicate that it can be reused and utilized rather than being disposed to the landfill. This paper presents a review of its applications and utilization.

  18. CALCIUM CARBONATE DISSOLUTION RATE IN LIMESTONE CONTACTORS

    Science.gov (United States)

    The rate of carbonate mineral dissolution from limestone was studied using a rotating disk apparatus and samples of limestone of varied composition. The purpose of this study was to determine the effect of limestone composition on the kinetics of carbonate mineral dissolution. Th...

  19. 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

  20. Coal Slag Attack-A Review

    Institute of Scientific and Technical Information of China (English)

    GUO Zongqi

    2004-01-01

    Although slagging coal gasifiers have served the commercial systems of electricity and chemical fertilizer productions for more than ten years, refractory service life still is a critical factor for gasifier availability. Some investigations were attracted, focusing on coal slag attack on high chromia refractories. A general introduction is made in order to have further understanding about slag corrosion in coal gasification environment. Microstructural deterioration and wear process of high chromia refractory in slagging gasifiers are discussed.

  1. Viscosity estimation for slags containing calcium fluoride

    Institute of Scientific and Technical Information of China (English)

    Qifeng Shu; Jiayun Zhang

    2005-01-01

    Based on recently published experimental data, the Riboud model was modified for viscosity estimation of the slags containing calcium fluoride. The estimated values were in good agreement with measured data. Reasonable estimation can be achieved using the modified Riboud model for mould fluxes and ESR (eletro slag remelting) slags. Especially for ESR slags, the modified Riboud model can provide much more precise values than the original Riboud model.

  2. Characteristics of acric luvisol on Magleš limestones

    Directory of Open Access Journals (Sweden)

    Knežević Milan

    2006-01-01

    Full Text Available Very deep soils with clearly differentiated two-layered profile physiography were studied on the limestones of the mountain Magleš. The very marked morphological differentiation of the profile is followed by significant textural differences and the variation of chemical characteristics of the soils. The profiles are 80-140 cm deep. The topsoil part of the solum, yellow-brown in colour, is 30-90 cm deep. Its textural class is silty-clay loam. Its chemical characteristics are very acid reaction and very low degree of base saturation. The relic (B horizon is reddish brown in colour, and it is characterized by a very high percentage of the colloidal clay, it is highly plastic and it has a compact structure. Its reaction is mostly weak acid to neutral, and the degree of base saturation is very high. The study results confirm the hypothesis of a very high impact of the Aeolian process on the formation of deep two-layered profiles on Magleš limestones.

  3. Structural characterization of a karstified limestone formation using GPR

    Science.gov (United States)

    Rousset, D.; Sénéchal, G.; Gaffet, S.

    2009-12-01

    The Laboratoire Souterrain à Bas Bruit (LSBB) at Rustrel - Pays d'Apt, France, is an Inter-disciplinary Underground Science and Technology Laboratory buried in a karstified limestone formation. A multidisciplinary program focused on water circulation monitoring is presently performed inside the tunnels. This program comprises the investigation of faults, fractures, karstification and stratigraphy ofthe limestone massif using GPR. We present the main results obtained from these data. The tunnel has been dug in lower cretaceous limestone which is characterized by a low clay content, high electrical resistivity which results in generally very low attenuation of electro-magnetic waves. 90% of the tunnels floor are made of concrete whereas other are made of bare limestone. This experimental site offers a unique opportunity of perfoming measurements within an unweathered limestone massif. The whole 3km long tunnel has been investigated using single offset shielded 250 MHz antennas in May 2009. Processing includes : DC and very low frequency removal, amplitude compensation preserving lateral variations, migration and time to depth conversion. When necessary predictive deconvolution has been applied to remove ringing effects. These data sets are characterized by good signal to noise ratio and a signal penetration down to 18 meters. These data allow us to accurately map the stratigraphy of the surrounding rocks across the concrete walls of the tunnel. Some 20 m deep vertical wells have been drilled inside the tunnel through observed reflectors. This is a strong validation of the GPR images. The estimated resolution is centimetric to decimetric and matches the required geologic accuracy. The GPR data set allows to extend previous geological results in depth, particularly in the concrete coated parts of the tunnel where conventional geological surveying is impossible. Thanks to the processing which preserves lateral amplitude variations, GPR sections exhibit prominent

  4. Melting Behaviour of Ferronickel Slags

    Science.gov (United States)

    Sagadin, Christoph; Luidold, Stefan; Wagner, Christoph; Wenzl, Christine

    2016-12-01

    The industrial manufacturing of ferronickel in electric furnaces produces large amounts of slag with strong acidic character and high melting points, which seriously stresses the furnace refractory lining. In this study, the melting behavior of synthetically produced ferronickel slags on magnesia as refractory material was determined by means of a hot stage microscope. Therefore, slags comprising the main oxides SiO2 (35-70 wt.%), MgO (15-45 wt.%) and Fe2O3 (5-35 wt.%) were melted in a graphite crucible and afterwards analyzed by a hot stage microscope. The design of experiments, which was created by the statistic software MODDE®, included 20 experiments with varying slag compositions as well as atmospheres. The evaluation of the test results occurred at three different characteristic states of the samples like the softening point according to DIN 51730 and the temperatures at which the area of residual cross-section of the samples amounted to 30% and 40%, respectively, of the original value depending of their SiO2/MgO ratio and iron oxide content. Additionally, the thickness of the zone influenced by the slag was measured and evaluated.

  5. Smelting Oxidation Desulfurization of Copper Slags

    Institute of Scientific and Technical Information of China (English)

    LI Lei; HU Jian-hang; WANG Hua

    2012-01-01

    According to the mechanism of sulfur removal easily through oxidation, the process of smelting oxidation desulfurization of copper slags is studied, which supplies a new thinking for obtaining the molten iron of lower sulfur content by smelting reduction of copper slags. Special attention is given to the effects of the holding temperature, the holding time and CaF2, CaO addition amounts on the desulfurization rate of copper slags. The results indicate that the rate of copper slags smelting oxidation desulfurization depends on the matte mass transfer rate through the slag phase. After the oxidation treatment, sulfur of copper slags can be removed as SO2 efficiently. Amount of Ca2+ of copper slags affects the desulfurization rate greatly, and the slag desulfurization rate is reduced by adding a certain amount of CaF2 and CaO. Compared with CaF2, CaO is negative to slags sulfur removal with equal Ca2+ addition. Under the air flow of 0.3 U/min, the sulfur content of copper slags can be reduced to 0. 004 67% in the condition of the holding time of 3 min and the holding temperature of 1 500 ℃. The sulfur content of molten iron is reduced to 0. 000 8 % in the smelting reduction of treated slags, and the problem of high sulfur content of molten iron obtained by smelting reduction with copper slag has been successively solved.

  6. PERFORMANCE OF PULVERIZED SLAG-SUBSTITUTED CEMENT

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The Portland cement is equivalently substituted by slag micropowders with various specific areas. The workability,activity and acid-corrosion resistance of the slag-substituted cements are investigated,the activation of gypsum is discussed,also the porosity and pore distribution of mortars of the slag micropowders cement are determined by mercury intrusion porosimetry.

  7. 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.

  8. Effects of body formulation and firing temperature to properties of ceramic tile incorporated with electric arc furnace (EAF) slag waste

    Science.gov (United States)

    Sharif, Nurulakmal Mohd; Lim, Chi Yang; Teo, Pao Ter; Seman, Anasyida Abu

    2017-07-01

    Significant quantities of sludge and slag are generated as waste materials or by-products from steel industries. One of the by-products is Electric Arc Furnace (EAF) steel slag which consists of oxides such as CaO, Al2O3 and FeO. This makes it possible for slag to partially replace the raw materials in ceramic tile production. In our preliminary assessment of incorporating the EAF slag into ceramic tile, it was revealed that at fixed firing temperature of 1150°C, the tile of composition 40 wt.% EAF slag - 60 wt.% ball clay has comparable properties with commercial ceramic tile. Thus, this current study would focus on effects of body formulation (different weight percentages of K-feldspar and silica) and different firing temperatures to properties of EAF slag added ceramic tile. EAF slag from Southern Steel Berhad (SSB) was crushed into micron size (EAF slag content was 40 wt.%) and milled with ball clay, K-feldspar and silica before compacted and fired at 1125°C and 1150°C. The EAF slag added tile was characterized in terms of water absorption, apparent porosity, bulk density, modulus of rupture (MOR) and phase analysis via X-ray diffraction (XRD). The composition of 40 wt.% EAF slag - 30 wt.% ball clay - 10 wt.% K-feldspar - 20 wt.% silica (10F_20S), fired at 1150°C showed the lowest water absorption, apparent porosity and highest bulk density due to enhancement of densification process during firing. However, the same composition of ceramic tile (10F_20S) had the highest MOR at lower firing temperature of 1125°C, contributed by presence of the highest total amount of anorthite and wollastonite reinforcement crystalline phases (78.40 wt.%) in the tile. Overall, both the water absorption and MOR of all ceramic tiles surpassed the requirement regulated by MS ISO 13006:2014 Standard (Annex G: Dry-pressed ceramic tile with low water absorption, Eb ≤ 0.50 % and minimum MOR of 35 MPa).

  9. CLAY AND CLAY-SUPPORTED REAGENTS IN ORGANIC SYNTHESES

    Science.gov (United States)

    CLAY AND CLAY-SUPPORTED REAGENTS HAVE BEEN USED EXTENSIVELY FOR SYNTHETIC ORGANIC TRANSFORMATIONS. THIS OVERVIEW DESCRIBES THE SALIENT STRUCTURAL PROPERTIES OF VARIOUS CLAY MATERIALS AND EXTENDS THE DISCUSSION TO PILLARED CLAYS AND REAGENTS SUPPORTED ON CLAY MATERIALS. A VARIET...

  10. 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.

  11. 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.

  12. INFLUENCE OF SEDIMENTARY ENVIRONMENT ON THE TECHNICAL PROPERTIES OF THE LOWER CRETACEOUS LIMESTONES FROM THE LAKOVIĆI QUARRY IN ISTRIA (CROATIA

    Directory of Open Access Journals (Sweden)

    Josip Tišljar

    1997-12-01

    Full Text Available The Lower Cretaceous limestones from the Lakovići quarry belong to the basal part of the Aptian limestones. These limestones are the beginning of the second transgressive-regrcssive megasequence in Istria which followed a general Upper Aptian emersion event. Within the approximately 50 m thick limestone sequence that is quarried, four facies units were defined according to their petrographic and sedimen-tological features. The following facies units were devided: A- Micritic limestones, which were deposited as shallowing-upward cycles and which begin with breccias containing clay matrix or terminate with dark-gray clays sporadically accompanied by deposition and redeposi-lion of black terrestrial and swamp clays, as well as sediments from bogs and pools that were developed in isolated bays and/or laggons; B -Grain supported limestone deposited as fine-grained to coarse-grained carbonate sands in a predominantly high-energy shallows, bars and sandy beaches; C - Micritic limestones deposited in restricted low-energy shallow subtidal environments; D - Drain supported limestones deposited as fine grained carbonate sands in high-energy shallows and bars. The results of petrological, sedimentological and technological investigations show that the limestones from each individual facies unit have different technical properties, notably porosity, bulk density and water absorption, i.e. the wide range of technical quality of the limestones quarried is a direct consequence of their facies characteristics. The outlined facies units enable separation of rock mass in the quarry not only by their petrological characteristics but also according to the technical quality of the rock.

  13. Biomarker generation from Type II-S kerogens in claystone and limestone during hydrous and anhydrous pyrolysis

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Koopmans, M.P.; Carson, F.C.; Lewan, M.D.

    1998-01-01

    A claystone and a limestone containing immature Type II-S kerogen were thermally matured in the presence and absence of water, to study the influence of water and clay minerals on the generation of biomarkers. In contrast to hydrous pyrolysis, anhydrous pyrolysis of the claystone did not generate bi

  14. New pollution reduction technologies through tank sealing of slag and ashes pits

    Energy Technology Data Exchange (ETDEWEB)

    Bruell, A.; Revenco, V. [Institutul de Stuidii Si Proiectari Energetice S.A. (ISPE), Bucharest (Hungary)

    2002-07-01

    Under the Romanian environment protection law provision no. 137/1995, the existing slag and ashes pits raise problems due to the exfiltrations from the pits tank towards the phreatic water sheet. The design includes the following steps to be taken: pit bed waterproofing under new works; bed ends sealing, parallel with pit aggradation for dumps in operation; waterproofing of aggradation dikes. The conventional solution is clay plating. When works are performed under bad weather conditions, and clay must be brought from remote distances, the clay plating solution should be compared to the geocomponents one. The latter area combination of geotextiles and bentone material that can be placed easily, joint in situ, and can be paid at negative temperatures. Once wet, geo components become impermeable. The paper describes the sealing performed at the slag and ashes pit of Vales Ceplea at Turceni thermal power plant, and the sealing solution being developed at the Beterega Nord slag and ashes pit at Rovinari thermal power plant. The necessary geophysical characteristics of the material are pointed out.

  15. Difference in BOF Slag Splashing in US and China

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Some differences in slag splashing between BOF steel works in USand China were investigated. The slag composition, melting point, and mineralogical phases of final slags from both countries were studied. The control of slag superheat is important to an effective slag coating.

  16. High Resolution Hydraulic Profiling and Groundwater Sampling using FLUTe™ System in a Fractured Limestone Setting

    DEFF Research Database (Denmark)

    Janniche, Gry Sander; Christensen, Anders G.; Grosen, Bernt;

    innovative investi-gation methods for characterization of the source zone hydrogeology and contamination, including FLUTe system hydraulic profiling and Water-FLUTe multilevel groundwater sampling, in fractured bryo-zoan limestone bedrock. High resolution hydraulic profiling was conducted in three cored......Characterization of the contaminant source zone architecture and the hydraulics is essential to develop accurate site specific conceptual models, delineate and quantify contaminant mass, perform risk as-sessment, and select and design remediation alternatives. This characterization is particularly...... challeng-ing in deposit types as fractured limestone. The activities of a bulk distribution facility for perchloroe-thene (PCE) and trichloroethene (TCE) at the Naverland site near Copenhagen, Denmark, has resulted in PCE and TCE DNAPL impacts to a fractured clay till and an underlying fractured limestone...

  17. Soil-gas diffusivity fingerprints of the dual porosity system in fractured limestone

    DEFF Research Database (Denmark)

    Claes, Niels; Chamindu, D.T.K.K.; Jensen, Jacob Birk;

    2010-01-01

    The presence of fractured vadose zones (e.g., limestone or clay tills) may potentially pose significant environmental concerns due to the rapid, preferential migration of gaseous plumes through interconnected pore networks. However, recent modelling studies related to fractured vadose zone...... processes are mostly limited to hydrogeological (water and solute) transport studies with very poor attention to the gaseous phase transport studies (Kristensen et al. 2010). This study characterizes fractured limestone soils for gas diffusion based on three different gas diffusivity fingerprints. The first...... fingerprint is a two-parameter exponential model, which mainly describes the gas diffusivity in the limestone matrix while taking both fracture connectivity and matrix pore connectivity into account. With the second fingerprint, we make a close observation of the tortuous matrix pore network by means...

  18. Effect of fillers Granulated slag on the durability of HPC in marine environment

    Directory of Open Access Journals (Sweden)

    Tebbal Nadia

    2014-04-01

    Full Text Available The combined effect of fillers of silica fume and blast furnace slag on the durability of high performance concretes was studied .The storage media are: seawater and tap water as reference. This work focuses on the effect of the incorporation of different amounts of milk more silica fume on the mechanical strength of concretes with limestone cements and its influence on sustainability with respect to marine. The results show that the addition of quantity 10%slag and 5% silica fume offers the best protection in marine waters .One of the indicators of sustainability are selected and monitored from 1 day to 28 days are variations of unconfined compressive strengths . The PH of the solution, especially related to the frequency of renewal baths, appears as an important parameter of aggressiveness.

  19. TRW Advanced Slagging Coal Combustor Utility Demonstration. Fourth Quarterly progress report, August 1989--October 1989

    Energy Technology Data Exchange (ETDEWEB)

    1989-12-31

    The TRW Advanced Slagging Coal Combustor Demonstration Project consists of retrofitting Orange and Rockland (O&R) Utility Corporation`s Lovett Plant Unit No. 3 with four (4) slagging combustors which will allow the gas/ou desip unit to fire 2.5 sulfur coal. The slogging combustor process will provide NO{sub x} and SO{sub x} emissions that meet NSPS and New York State Envirommental Standards. TRW-CBU scope of work includes the engineering, design and supply of the slogging combustors, coal and limestone feed systems and a control system for these components. During this report period, the design activities for all systems progressed to permit the release of specifications and requests for proposals. Award of contracts for long-delivery items and major equipment are being placed to meet the revised program schedule.

  20. Common clay and shale

    Science.gov (United States)

    Virta, R.L.

    2011-01-01

    The article discusses the latest developments in the global common clay and shale industry, particularly in the U.S. It claims that common clay and shale is mainly used in the manufacture of heavy clay products like brick, flue tile and sewer pipe. The main producing states in the U.S. include North Carolina, New York and Oklahoma. Among the firms that manufacture clay and shale-based products are Mid America Brick & Structural Clay Products LLC and Boral USA.

  1. Thermo-poroelastic response of an argillaceous limestone

    Science.gov (United States)

    Selvadurai, Patrick; Najari, Meysam

    2016-04-01

    Argillaceous limestones are now being considered by many countries that intend to develop deep geologic storage facilities for siting both high-level and intermediate- to low-level nuclear fuel wastes. In deep geologic settings for high level nuclear wastes, the heating due to radioactive decay is transmitted through an engineered barrier, which consists of the waste container and an engineered geologic barrier, which consists of an encapsulating compacted bentonite. The heat transfer process therefore leads to heating of the rock mass where the temperature of the rock is substantially lower than the surface temperature of the waste container. This permits the use of mathematical theories of poroelastic media where phase transformations, involving conversion of water to a vapour form are absent. While the thermo-poroelastic responses of geologic media such as granite and porous tuff have been investigated in the literature, the investigation of thermo-poroelastic responses of argillaceous limestones is relatively new. Argillaceous limestones are considered to be suitable candidates for siting deep geologic repositories owing to the ability to accommodate stress states with generation of severe defects that can influence their transmissivity characteristics. Also the clay fraction in such rocks can contribute to long term healing type phenomena, which is a considerable advantage. This research presents the results of a laboratory investigation and computational modelling of the same that examines the applicability of the theory of thermo-poroelasticity, which extend Biot's classical theory of poroelasticity to include uncoupled heat conduction. The experimental configuration involves the boundary heating of a cylinder of the Cobourg Limestone from southern Ontario, Canada. The cylinder measuring 150 mm in diameter and 278 mm in length contains an axisymmetric fluid-filled cylindrical cavity measuring 26 mm in diameter and 139 mm in length. Thermo-poroelastic effects

  2. Modified clay sorbents

    Energy Technology Data Exchange (ETDEWEB)

    Fogler, H.S.; Srinivasan, K.R.

    1990-04-10

    This patent describes a clay-based sorbent. It comprises a clay having an external surface and lamellar layers; and cationic surfactant ions having a hydrocarbon portion and a cationic head portion, the cationic surfactant ions being irreversibly bound to the external surface by the hydrocarbon portion. This patent also describes cetylpyridinium-aluminum hydroxy-montmorillonite; the clay-based sorbent wherein the clay is a non-expandable clay; and the clay-based sorbent wherein the cationic surfactant ions are selected from the group consisting of ionized cetylpyridinium chloride and cetylakonium chloride.

  3. The Sulfide Capacity of Iron Oxide-Rich Slags

    Science.gov (United States)

    Motlagh, M.

    1988-03-01

    The relationship between the sulfide capacity of slags rich in iron oxide and the sulfur partition ratio between the metal and slag is strongly related to the slag's iron oxide concentration. For slags containing little or no lime, this relationship is linear for a constant concentration of iron oxide in the slag. The effect of silica on changes in the sulfide capacity of slags rich in iron oxide is similar to that of basic steel-making slags, particularly at low activity of silica in slag.

  4. The use of limestone powder as an alternative cement replacement ...

    African Journals Online (AJOL)

    The use of limestone powder as an alternative cement replacement material: An ... The laboratory test results revealed that up to 15% replacement of clinker by fine ... Early strength, Limestone filler, Loss on ignition, Portland limestone cement ...

  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. Soil Stabilisation Using Ground Granulated Blast Furnace Slag

    Directory of Open Access Journals (Sweden)

    Ashish Kumar Pathak

    2014-05-01

    Full Text Available 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 obtained from the blast furnace of cement plant, which is the byproduct of iron (from ACC plant, sindri. It is generally obtained in three shaped one is air cooled, foamed shaped and another is in granulated shaped. The use of by-product materials for stabilisation has environmental and economic benefits. Ground granulated blast furnace slag (GGBS material is used in the current work to stabilise soil (clay. The main objectives of this research were to investigate the effect of GGBS on the engineering property (optimum moisture content and maximum dry density, plastic limit, liquid limit, compaction, unconfined compressive strength, triaxial and California bearing ratio test of the soil and determine the engineering properties of the stabilised.

  7. Novel sintered ceramic materials incorporated with EAF carbon steel slag

    Science.gov (United States)

    Karayannis, V.; Ntampegliotis, K.; Lamprakopoulos, S.; Papapolymerou, G.; Spiliotis, X.

    2017-01-01

    In the present research, novel sintered clay-based ceramic materials containing electric arc furnace carbon steel slag (EAFC) as a useful admixture were developed and characterized. The environmentally safe management of steel industry waste by-products and their valorization as secondary resources into value-added materials towards circular economy have attracted much attention in the last years. EAF Carbon steel slag in particular, is generated during the manufacture of carbon steel. It is a solid residue mainly composed of rich-in- Fe, Ca and Si compounds. The experimental results show that the beneficial incorporation of lower percentages of EAFC up to 6%wt. into ceramics sintered at 950 °C is attained without significant variations in sintering behavior and physico-mechanical properties. Further heating up to 1100 °C strongly enhances the densification of the ceramic microstructures, thus reducing the porosity and strengthening their mechanical performance. On the other side, in terms of thermal insulation behavior as well as energy consumption savings and production cost alleviation, the optimum sintering temperature appears to be 950 °C.

  8. 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.

  9. The use of blast furnace slag

    OpenAIRE

    V. Václavík; V. Dirner; T. Dvorský; J. Daxner

    2012-01-01

    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.

  10. Use of steel slag to neutralize acid mine drainage (AMD in sulfidic material from a uranium mine

    Directory of Open Access Journals (Sweden)

    Camila Marcon de Carvalho Leite

    2013-06-01

    Full Text Available Acid Mine Drainage (AMD is one of the main environmental impacts caused by mining. Thus, innovative mitigation strategies should be exploited, to neutralize acidity and prevent mobilization of trace elements in AMD. The use of industrial byproducts has been considered an economically and environmentally effective alternative to remediate acid mine drainage. Therefore, the objective of this study was to evaluate the use of steel slag to mitigate acid mine drainage in a sulfidic material from a uranium mine, as an alternative to the use of limestone. Thus, increasing doses of two neutralizing agents were applied to a sulfidic material from the uranium mine Osamu Utsumi in Caldas, Minas Gerais State. A steel slag from the company ArcelorMittal Tubarão and a commercial limestone were used as neutralizing agents. The experiment was conducted in leaching columns, arranged in a completely randomized, [(2 x 3 + 1] factorial design, consisting of two neutralizing agents, three doses and one control, in three replications, totaling 21 experimental units. Electrical conductivity (EC, pH and the concentrations of Al, As, Ca, Cd, Cu, Fe, Mn, Ni, S, Se, and Zn were evaluated in the leached solutions. The trace element concentration was evaluated by ICP-OES. Furthermore, the CO2 emission was measured at the top of the leaching columns by capturing in NaOH solution and titration with HCl, in the presence of BaCl2. An increase in the pH of the leachate was observed for both neutralizing agents, with slightly higher values for steel slag. The EC was lower at the higher lime dose at an early stage of the experiment, and CO2 emission was greater with the use of limestone compared to steel slag. A decrease in trace element mobilization in the presence of both neutralizing agents was also observed. Therefore, the results showed that the use of steel slag is a suitable alternative to mitigate AMD, with the advantage of reducing CO2 emissions to the atmosphere

  11. Picture analysing method of slag foaming behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Juhart, M.; Peter, M.; Koch, K. [Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany). Inst. fuer Metallurgy; Lamut, J. [Faculty of Natural Science and Technology, Univ. Ljubljana, Ljubljana (Slovenia)

    2001-03-01

    Hot tests of foaming behaviour of steelmaking slags were conducted on a laboratory scale up to 1760 C using a Tammann furnace. The foaming behaviour of the slags was quantified on the basis of a new measuring method. The volume increase and the progress of the foaming process can be continuously observed and calculated by means of picture analysis. The gas content of foaming slags was compared with the results of the measurements performed in steel plants. The influence of the magnesia content on the foaming behaviour is investigated. The chemical composition of the slag is beside the CO evolution the decisive factor influencing slag foaming behaviour. The highest volume increase values observed lie in the region of 2500% in relation to the initial volume. (orig.)

  12. Leaching of heavy metals from steelmaking slags

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, J. F. P.; Pino, C. G.

    2006-07-01

    Leaching tests with EAF and Ladle slags were performed, using a flow through tests and the standard batch test DIN 38414-S4. The previous method was used to simulate the leaching behaviour of steel slags under landfill. the chemical analysis of the leachates during this period shows, in general, for both types of slag, and increase of heavy metal releases with ageing. Standard test method DIN 38414-S4 was used to evaluate leachability of heavy metals by water in unprocessed slags. After more than one year of trials, slang samples submitted to these trials presented very low total leaching levels. The most extracted elements are calcium and magnesium. Nevertheless, in flow-though test, calcium and magnesium leached from solid slags are below 0.5% and all other metals below 0.1%. Leachates obtained with DIN 38414-S4 present, as expected, higher leaching values; however, these are inferior to 5% (Ca) and 1% (other elements). (Author) 12 refs.

  13. ALKALI-ACTIVATED CEMENT MORTARS CONTAINING RECYCLED CLAY-BASED CONSTRUCTION AND DEMOLITION WASTE

    OpenAIRE

    Puertas, F.; Santos, R.; Alonso M. M.; Del Rio M.

    2015-01-01

    The use of clay-based waste as an aggregate for concrete production is an amply studied procedure. Nonetheless, research on the use of this recycled aggregate to prepare alkaline cement mortars and concretes has yet to be forthcoming. The present study aimed to determine: the behaviour of this waste as a pozzolan in OPC systems, the mechanical strength in OPC, alkali-activated slag (AAS) and fly ash (AAFA) mortars and the effect of partial replacement of the slag and ash themselves with groun...

  14. Depth to top of the Minnekahta Limestone

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set is a polygon coverage created in ARC/INFO that represents the depth to the top of the Minnekahta Limestone below the land surface, Black Hills, South...

  15. Depth to top of the Madison Limestone

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set is a polygon coverage created in ARC/INFO that represents the depth to the top of the Madison Limestone below the land surface, Black Hills, South...

  16. Gravitational segregation of liquid slag in large ladle

    Directory of Open Access Journals (Sweden)

    J. Chen

    2012-04-01

    Full Text Available The process of gravitational segregation makes liquid steel slag components occur differentiation. And it shows that the upper part slag in the slag ladle contains higher CaO; and the lower part slag contains higher SiO2. The content of MgO (5,48 % in the upper part slag is higher than that of the lower part (2,50 %, and only Al2O3 content of the upper and the lower part slag is close to each other. The difference of chemical compositions in the slag ladle shows that there is gravitational segregation during slow solidification of liquid steel slag, which will has some impact of the steel slag processing on the large slag ladle.

  17. The behavior limestone under explosive load

    Science.gov (United States)

    Orlov, M. Yu; Orlova, Yu N.; Bogomolov, G. N.

    2016-11-01

    Limestone behavior under explosive loading was investigated. The behavior of the limestone by the action of the three types of explosives, including granular, ammonite and emulsion explosives was studied in detail. The shape and diameter of the explosion craters were obtained. The observed fragments after the blast have been classified as large, medium and small fragments. Three full-scale experiments were carried out. The research results can be used as a qualitative test for the approbation of numerical methods.

  18. Co-treatment of gypsum sludge and Pb/Zn smelting slag for the solidification of sludge containing arsenic and heavy metals.

    Science.gov (United States)

    Li, Yuan-Cheng; Min, Xiao-Bo; Chai, Li-Yuan; Shi, Mei-Qing; Tang, Chong-Jian; Wang, Qing-Wei; Liang, Yan-Jie; Lei, Jie; Liyang, Wen-Jun

    2016-10-01

    Wastewater treatment sludge from a primary lead-zinc smelter is characterized as hazardous waste and requires treatment prior to disposal due to its significant arsenic and heavy metals contents. This study presents a method for the stabilization of arsenic sludge that uses a slag based curing agent composed of smelting slag, cement clinker and limestone. The Unconfined Compressive Strength (UCS) test, the China Standard Leaching Test (CSLT), and the Toxicity Characteristic Leaching Procedures (TCLP) were used to physically and chemically characterize the solidified sludge. The binder ratio was determined according to the UCS and optimal experiments, and the optimal mass ratio of m (smelting slag): m (cement clinker): m (gypsum sludge): m (limestone) was 70:13:12:5. When the binder was mixed with arsenic sludge using a mass ratio of 1:1 and then maintained at 25 °C for 28 d, the UCS reached 9.30 MPa. The results indicated that the leached arsenic content was always less than 5 mg/L, which is a safe level, and does not contribute to recontamination of the environment. The arsenic sludge from the Zn/Pb metallurgy plant can be blended with cement clinker and smelting slag materials for manufacturing bricks and can be recycled as construction materials. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. [Limestone and pyrite-limestone constructed wetlands for treating river water].

    Science.gov (United States)

    Zhang, Jing; Li, Rui-hua; Li, Jie; Hu, Jun-song; Sun, Qian-qian

    2013-09-01

    Polluted river water was treated with limestone and pyrite-limestone subsurface horizontal constructed wetlands. The aims were to know the performance of two wetlands on removal of common pollutants, especially nitrogen and phosphorus, and analyze the actions of these minerals. The relationship between hydraulic retention time and purification performance of two constructed wetlands was studied. The optimal hydraulic retention time for pollutant removal was about 3 d, The average removal efficiency of COD, TN and TP were 51%, 70% and 95%, respectively. With same influent and hydraulic loading, the average removal efficiency of COD, NH4+ -N, TN and TP were 53.93%, 82.13%, 66%, 50.9%, and 51.66%, 77.43%, 72.06%, 97.35% for limestone and pyrite-limestone constructed wetlands, respectively. There were few differences between limestone and pyrite-limestone wetlands on COD removal, but the nitrogen and phosphorus removal of pyrite-limestone constructed wetland was higher than that of limestone constructed wetland. The phosphorus removal of pyrite-limestone wetland was more efficiency and stable, not affected by temperature.

  20. A numerical model for chemical reaction on slag layer surface and slag layer behavior in entrained-flow gasifier

    Directory of Open Access Journals (Sweden)

    Liu Sheng

    2013-01-01

    Full Text Available The paper concerns with slag layer accumulation, chemical reaction on slag layer surface, and slag layer flow, heat and mass transfer on the wall of entrained-flow coal gasifier. A slag layer model is developed to simulate slag layer behaviors in the coal gasifier. This 3-D model can predict temperature, slag particle disposition rate, disposition particle composition, and syngas distribution in the gasifier hearth. The model is used to evaluate the effects of O2/coal ratio on slag layer behaviors.

  1. Study of decomposing carbonyl slag

    Institute of Scientific and Technical Information of China (English)

    CHEN Ai-liang; SUN Pei-mei; ZHAO Zhong-wei; LI Hong-gui; CHEN Xing-yu

    2006-01-01

    A new technology was put forward to deal with the carbonyl slag at low acidity and low oxygen pressure in the kettle.With the orthogonal experiments for analyzing the sequence of four factors and some single factor experiments for the best conditions. The best conditions are used for extracting nickel, cobalt and copper and enriching precious metals: the cupric ion concentration is 5 g/L; and pH=6; the sulfur coefficient is 1.4; the oxygen pressure is 0.08 MPa; the time bubbling oxygen is 20 min;the ratio of liquid to solid is 8:1; the leaching time is 2 h; the heating time is 2.5 h. The leaching rates of nickel and cobalt are more than 98% and that of copper is above 97%. Nickel and cobalt can be separated efficiently from copper and precious metals from the carbonyl slag. Moreover, its leaching liquor has less copper. Nickel and cobalt can be reclaimed only once. During the whole process,the leaching rates of Au and Ag are more than 99.9%, while other precious metals are still in the residue without any loss.

  2. Hydrothermal synthesis of xonotlite from carbide slag

    Institute of Scientific and Technical Information of China (English)

    Jianxin Cao; Fei Liu; Qian Lin; Yu Zhang

    2008-01-01

    Carbide slag was used as the calcareous materials for the first time to prepare xonotlite via dynamic hydrothermal synthesis.The effects of influential factors including different calcination temperatures,pretreatment methods of the carbide slag and process param-eters of hydrothermal synthesis on the microstructure and morphology of xonotlite were explored using XRD and SEM techniques.The results indicate that the carbide slag after proper calcination could be used to prepare pure xonotlite;and different calcination tern-peratures have little effect on the crystallinity of synthesized xonotlitc,but have great impact on the morphology of secondary particles.The different pretreatment methods of the carbide slag pose great impact on the crystallinity and morphology of secondary particles of xonotlite.Xonotlite was also synthesized from pure CaO under the salne experimental conditions as that prepared from calcined carbide slag for comparison.Little amount of impurities in carbide slag has no effect on the mechanism of hydrothermal synthesizing xonotlite from carbide slag.

  3. Coexistence Theory of Slag Structure and Its Application to Calculation of Oxidizing Capability of Slag Melts

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The coexistence theory of slag structure and it's application to calculation of the oxidizing capabilities of slag melts is described. It is shown that the law of mass action can be widely applied to the calculation of oxidizing capabilities of slag melts in combination with the coexistence theory of slag structure.For slag melts containing basic oxides FeO and MnO, their oxidizing capabilities can be expressed by NFetO=NFeO+6NFe2O3, while for slag melts containing basic oxides CaO, MgO, etc., in addition to FeO and MnO, their oxidizing capabilities can be given as NFetO=NFeO+6NFe2O3+8NFe3O4.

  4. Effects of limestone petrography and calcite microstructure on OPC clinker raw meals burnability

    Science.gov (United States)

    Galimberti, Matteo; Marinoni, Nicoletta; Della Porta, Giovanna; Marchi, Maurizio; Dapiaggi, Monica

    2016-12-01

    Limestone represents the main raw material for ordinary Portland cement clinker production. In this study eight natural limestones from different geological environments were chosen to prepare raw meals for clinker manufacturing, aiming to define a parameter controlling the burnability. First, limestones were characterized by X-Ray Fluorescence, X-Ray Powder Diffraction and Optical Microscopy to assess their suitability for clinker production and their petrographic features. The average domains size and the microstrain of calcite were also determined by X-Ray Powder Diffraction line profile analysis. Then, each limestone was admixed with clay minerals to achieve the adequate chemical composition for clinker production. Raw meals were thermally threated at seven different temperatures, from 1000 to 1450 °C, to evaluate their behaviour on heating by ex situ X-Ray Powder Diffraction and to observe the final clinker morphology by Scanning Electron Microscopy. Results indicate the calcite microstrain is a reliable parameter to predict the burnability of the raw meals, in terms of calcium silicates growth and lime consumption. In particular, mixtures prepared starting from high-strained calcite exhibit a better burnability. Later, when the melt appears this correlation vanishes; however differences in the early burnability still reflect on the final clinker composition and texture.

  5. Thermostability of montmorillonitic clays

    OpenAIRE

    Petr Jelínek; Dobosz, Stanisław M.; Jaroslav Beňo

    2014-01-01

    Bentonite is one of the most widespread used clays connected with various applications. In the case of foundry technology, bentonite is primarily used as a binder for mold manufacture. Thermal stability of bentonites is a natural property of clay minerals and it depends on the genesis, source and chemical composition of the clay. This property is also closely connected to bentonite structure. According to DTA analysis if only one peak of dehydroxylation is observed (about 600 ºC), the cis- is...

  6. Novel Sessile Drop Software for Quantitative Estimation of Slag Foaming in Carbon/Slag Interactions

    Science.gov (United States)

    Khanna, Rita; Rahman, Mahfuzur; Leow, Richard; Sahajwalla, Veena

    2007-08-01

    Novel video-processing software has been developed for the sessile drop technique for a rapid and quantitative estimation of slag foaming. The data processing was carried out in two stages: the first stage involved the initial transformation of digital video/audio signals into a format compatible with computing software, and the second stage involved the computation of slag droplet volume and area of contact in a chosen video frame. Experimental results are presented on slag foaming from synthetic graphite/slag system at 1550 °C. This technique can be used for determining the extent and stability of foam as a function of time.

  7. Blast furnace slags as sorbents of phosphate from water solutions.

    Science.gov (United States)

    Kostura, Bruno; Kulveitová, Hana; Lesko, Juraj

    2005-05-01

    The paper is focused on the sorption of phosphorus from aqueous solutions by crystalline and amorphous blast furnace slags. Slag sorption kinetics were measured, adsorption tests were carried out and the effect of acidification on the sorption properties of slags was studied. The kinetic measurements confirmed that the sorption of phosphorus on crystalline as well as amorphous slags can be described by a model involving pseudo-second-order reactions. For all slag types, phosphorus sorption follows the Langmuir adsorption isotherm. The acid neutralizing capacities of crystalline and amorphous slags were determined. In the case of the crystalline slags, buffering intervals were found to exist during which the slag minerals dissolve in the sequence bredigite-gehlenite-diaspor. There is a high correlation (R2=0.9989) between ANC3.8 and the saturation capacities of crystalline and amorphous slags.

  8. Slags from steel production: Properties and their utilization

    Directory of Open Access Journals (Sweden)

    J. Vlcek

    2013-07-01

    Full Text Available During steel production a considerable amount of slags is produced. In addition to its usual processing, as recycling in device for steel production and preparation of aggregates, it is also possible to apply less common slag processing ways. Depending on cooling mode of the steel slags these may show some binding properties. Geopolymer type binders can be prepared from the slag using alkali activators or the hydraulic properties of the dicalciumsilicate present in the slag can be induced by water. The paper summarizes present state of material utilisation of the steel slags with focus on emphasize of the possible sources of the slag volume instability. The influence of process of slag cooling on its phase composition is documented. It was also found that slags from real sources show different parameters compared to samples obtained for laboratory examination.

  9. Settling of copper drops in molten slags

    Science.gov (United States)

    Warczok, A.; Utigard, T. A.

    1995-02-01

    The settling of suspended metal and sulfide droplets in liquid metallurgical, slags can be affected by electric fields. The migration of droplets due to electrocapillary motion phenomena may be used to enhance the recovery of suspended matte/metal droplets and thereby to increase the recovery of pay metals. An experimental technique was developed for the purpose of measuring the effect of electric fields on the settling rate of metallic drops in liquid slags. Copper drops suspended in CaO-SiO2-Al2O3-Cu2O slags were found to migrate toward the cathode. Electric fields can increase the settling rate of 5-mm-diameter copper drops 3 times or decrease the settling until levitation by reversal of the electric field. The enhanced settling due to electric fields decreases with increasing Cu2O contents in the slag.

  10. Electroreduction Kinetics for Molten Oxide Slags

    Institute of Scientific and Technical Information of China (English)

    GAO Yun-ming; CHOU Kuo-chih; GUO Xing-min; WANG Wei

    2007-01-01

    The oxygen-ion conductor, the reducing agent, and the molten oxide slag containing electroactive matter were used as constituent of a galvanic cell. Metal was directly electroreduced from molten slag using a short-circuit galvanic cell. The following galvanic cell was assembled in the present experiment: graphite rod, [O]Fe-C saturated|ZrO2(MgO)|Cu(l)+(FeO)(slag), and molybdenum wire. The FeO electroreduction reaction was studied through measuring short circuit current by controlling factors such as temperature, the FeO content in molten slags, and the external circuit resistance. An overall kinetics model was developed to describe the process of FeO electroreduction. It was found that the modeled curves were in good agreement with the experimental values. The new oxide reduction method in the metallurgy with controlled oxygen flow was proposed and the metallurgical theory with controlled oxygen flow was developed.

  11. 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.

  12. Sulfide capacities of fayalite-base slags

    Science.gov (United States)

    Simeonov, S. R.; Sridhar, R.; Toguri, J. M.

    1995-04-01

    The sulfide capacities of fayalite-base slags were measured by a gas-slag equilibration technique under controlled oxygen and sulfur potentials similar to those encountered in the pyrometallurgical processing of nonferrous metals. The oxygen pressure range was from 10-9.5 to 10-11 MPa and the sulfur pressure range from 10-3 to 10-4.5 MPa, over a temperature range of 1473 to 1623 K. The slags studied were FeO-SiO2 at silica saturation and those with addition of CaO, MgO, and Al2O3 to determine their effect on sulfide capacities. For these slags, the sulfide capacities were found to vary from 10-3.3 to 10-5. The sulfide capacities increased with increasing temperature from 1473 to 1623 K. A comparison of the reported plant data on sulfur content of industrial slags shows good agreement with the present experimental results. The present data will be useful in estimating metal losses in slag due to metal sulfide entrainment in nonferrous smelters.

  13. Calculation of sulfide capacities of multicomponent slags

    Science.gov (United States)

    Pelton, Arthur D.; Eriksson, Gunnar; Romero-Serrano, Antonio

    1993-10-01

    The Reddy-Blander model for the sulfide capacities of slags has been modified for the case of acid slags and to include A12O3 and TiO2 as components. The model has been extended to calculate a priori sulfide capacities of multicomponent slags, from a knowledge of the thermodynamic activities of the component oxides, with no adjustable parameters. Agreement with measurements is obtained within experimental uncertainty for binary, ternary, and quinary slags involving the components SiO2-Al2O3-TiO2-CaO-MgO-FeO-MnO over wide ranges of composition. The oxide activities used in the computations are calculated from a database of model parameters obtained by optimizing thermodynamic and phase equilibrium data for oxide systems. Sulfur has now been included in this database. A computing system with automatic access to this and other databases has been developed to permit the calculation of the sulfur content of slags in multicomponent slag/metal/gas/solid equilibria.

  14. Clay Portrait Boxes

    Science.gov (United States)

    Wilbert, Nancy Corrigan

    2009-01-01

    In an attempt to incorporate sculptural elements into her ceramics program, the author decided to try direct plaster casting of the face to make a plaster mold for clay. In this article, the author shares an innovative ceramics lesson that teaches students in making plaster casts and casting the face in clay. This project gives students the…

  15. Columns in Clay

    Science.gov (United States)

    Leenhouts, Robin

    2010-01-01

    This article describes a clay project for students studying Greece and Rome. It provides a wonderful way to learn slab construction techniques by making small clay column capitols. With this lesson, students learn architectural vocabulary and history, understand the importance of classical architectural forms and their influence on today's…

  16. Clay Mineral: Radiological Characterization

    Science.gov (United States)

    Cotomácio, J. G.; Silva, P. S. C.; Mazzilli, B. P.

    2008-08-01

    Since the early days, clays have been used for therapeutic purposes. Nowadays, most minerals applied as anti-inflammatory, pharmaceutics and cosmetic are the clay minerals that are used as the active ingredient or, as the excipient, in formulations. Although their large use, few information is available in literature on the content of the radionuclide concentrations of uranium and thorium natural series and 40K in these clay minerals. The objective of this work is to determine the concentrations of 238U, 232Th, 226Ra, 228Ra, 210Pb and 40K in commercial samples of clay minerals used for pharmaceutical or cosmetic purposes. Two kinds of clays samples were obtained in pharmacies, named green clay and white clay. Measurement for the determination of 238U and 232Th activity concentration was made by alpha spectrometry and gamma spectrometry was used for 226Ra, 228Ra, 210Pb and 40K determination. Some physical-chemical parameters were also determined as organic carbon and pH. The average activity concentration obtained was 906±340 Bq kg-1 for 40K, 40±9 Bq kg-1 for 226Ra, 75±9 Bq kg-1 for 228Ra, 197±38 Bq kg-1 for 210Pb, 51±26 Bq kg-1 for 238U and 55±24 Bq kg-1 for 232Th, considering both kinds of clay.

  17. Siderophore sorption to clays.

    Science.gov (United States)

    Maurice, Patricia A; Haack, Elizabeth A; Mishra, Bhoopesh

    2009-08-01

    Siderophores are low molecular weight organic ligands exuded by some aerobic organisms and plants to acquire Fe under Fe-limited conditions. The hydroxamate siderophores may sorb to aluminosilicate clays through a variety of mechanisms depending upon the nature of the clay and of the siderophore along with solution conditions such as pH, ionic strength, and presence of metal cations. They may also affect metal binding to clays. Here, we review previous studies of siderophore sorption to aluminosilicate clays; briefly discuss how the techniques of X-ray diffractometry, Fourier-transform infrared spectroscopy, and X-ray absorption spectroscopy may be applied to such studies; review effects of siderophores on metal sorption to clays; and highlight some areas for future research.

  18. Laser Removal of Protective Treatments on Limestone

    Science.gov (United States)

    Gómez-Heras, M.; Rebollar, E.; Alvarez de Buergo, M.; Oujja, M.; Fort, R.; Castillejo, M.

    This work presents an investigation of the laser removal of polymeric materials acting as consolidants and water-repellents on limestone used on buildings of architectural and artistic value. The removal of the consolidant Paraloid B-72 and the water-repellent product Tegosivin HL-100, applied on samples of Colmenarand Bateig limestone, was studied as a function of the laser wavelength, by using the four harmonics of a Q-switched Nd:YAG laser (1064, 532, 355 and 266 nm). Elimination of the coatings and subsequent surface modifications were monitored through colorimetry, roughness measurements and scanning electron microscopy (SEM). The fundamental laser radiation was effective in removing the treatments, although thermal alteration processes were induced on the calcite crystals of the limestone. The best results were obtained by irradiation in the near UV at 355 nm.

  19. Effect of Limestone Fillers the Physic-Mechanical Properties of Limestone Concrete

    Science.gov (United States)

    bederina, Madani; makhloufi, Zoubir; bouziani, Tayeb

    This work focuses on the exploitation of local industrial wastes and their use in the formulation of new concretes which can be used in local constructions. The valorised materials are limestone crushing sand (0/5 mm) and limestone fillers (80 μm). The two materials are extracted from local aggregate crushing wastes. Thus, and since the used gravels are also of limestone nature, the formulated composite is a limestone concrete. So this study constitutes an experimental work that aims at the study of the effect of the addition of limestone fillers on the physico-mechanical behaviour of limestone concrete. To carry out this study, different proportions of fillers ranging from 0 to 40% were considered. Very important results have been achieved on the workability and strength. By increasing the amount of limestone filler in concrete, the first one improves, but the second one increases then decreases passing by an optimal content of fillers which gives a maximum mechanical strength. Finally, and concerning the dimensional variations, it is noteworthy that they decrease at the beginning till an optimal value of fillers content, but beyond this optimum, they start increasing without exceeding recommended values.

  20. Heat Flux Through Slag Film and Its Crystallization Behavior

    Institute of Scientific and Technical Information of China (English)

    TANG Ping; XU Chu-shao; WEN Guang-hua; ZHAO Yan-hong; QI Xin

    2008-01-01

    An experimental apparatus for simulating copper mold is used to quantify the heat flux through the slag film and to obtain a solid slag for further determining its crystallization behavior.The result indicates that both the chemical composition of the mold powder and the cooling rate have an important influence on the heat flux through the slag film.With increasing the binary hasicity,the heat flux of slag film decreases at first,reaches the minimum at the basicity of 1.4,and then increases,indicating that the maximum binary basicity is about 1.4 for selecting"mild cooling"mold powder.The heat transfer through the slag film can be specified in terms of the crystalline ratio and the thickness of the slag film.Reerystallization of the solid slag occurs and must be considered as an important factor that may influence the heat transfer through the solid slag layer.

  1. Osmundiron, cleaved iron bars and slags (Osmundjern, kloder og kalotslagger)

    DEFF Research Database (Denmark)

    Buchwald, Vagn Fabritius

    1996-01-01

    Investigation of so-called Osmund iron, iron bars and slags from iron production in the medieval ages.......Investigation of so-called Osmund iron, iron bars and slags from iron production in the medieval ages....

  2. Multi-scale characterization of monument limestones

    CERN Document Server

    Beck, K; Al-Mukhtar, M; Rozenbaum, Olivier

    2003-01-01

    Among the parameters influencing stone deterioration, moisture and water movements through the pore network are essential. This communication presents differents methods to characterize stones and to determinate the water transfer properties. Results are analysed for two limestones having similar total porosity, but characterized by different pore networks. These different porous systems govern dissimilar water properties.

  3. Influence of sulfate on cement mixtures containing fly ash or blast-furnace slag

    Energy Technology Data Exchange (ETDEWEB)

    Bhanumathidas, N.; Kalidas, N. [Inst. for Solid Waste Research and Ecological Balance, Visakhapatnam (India)

    2001-07-01

    The development of FaL-G, a cementitious mixture of fly ash, lime and gypsum was initiated by the desire to improve the early strength of blended portland cement. Fly ash and granulated blast-furnace slag both contain reactive alumina. The strength of some fly ash-lime mixtures, in the presence of gypsum, can be enhanced 3 to 6 times at all ages. This study showed that high-volume fly ash blended portland cements also increase in strength with the addition of gypsum or anhydrite. Ground granulated blast-furnace slag behaves in a similar manner to blended portland cement. The enhanced strength is due to the formation of calcium sulphoaluminate hydrates. This study shows that it is possible to use large volumes of fly ash and slag to conserve on cost-intensive and energy-intensive clinker. Bricks and blocks made according to FaL-G technology are replacing fired clay bricks used in masonry construction. This research is of particular interest for the conservation of agricultural soils, minerals and energy. The study also shows that it is possible to convert major industrial waste into useful construction products. 7 refs., 3 tabs., 1 fig.

  4. Investigations of a Cretaceous limestone with spectral induced polarization and scanning electron microscopy

    Science.gov (United States)

    Johansson, Sara; Sparrenbom, Charlotte; Fiandaca, Gianluca; Lindskog, Anders; Olsson, Per-Ivar; Dahlin, Torleif; Rosqvist, Håkan

    2017-02-01

    Characterization of varying bedrock properties is a common need in various contexts, ranging from large infrastructure pre-investigations to environmental protection. A direct current resistivity and time domain induced polarization (IP) survey aiming to characterize properties of a Cretaceous limestone was carried out in the Kristianstad basin, Sweden. The time domain IP data was processed with a recently developed method in order to suppress noise from the challenging urban setting in the survey area. The processing also enabled extraction of early decay times resulting in broader spectra of the time decays and inversion for Cole-Cole parameters. The aims of this study is to investigate if large-scale geoelectrical variations as well as small-scale structural and compositional variations exist within the Kristianstad limestone, and to evaluate the usefulness of Cole-Cole inverted IP data in early time ranges for bedrock characterization. The inverted sections showed variations within the limestone that could be caused by variations in texture and composition. Samples from a deep drilling in the Kristianstad basin were investigated with scanning electron microscopy and energy dispersive X-ray spectroscopy, and the results showed that varying amounts of pyrite, glauconite and clay matrix were present at different levels in the limestone. The local high IP anomalies in the limestone could be caused by these minerals otherwise the IP responses were generally weak. There were also differences in the texture of the limestone at different levels, governed by fossil shapes and composition, proportions of calcareous cement and matrix as well as amount of silicate grains. Textural variations may have implications on the variation in Cole-Cole relaxation time and frequency factor. However, more research is needed in order to directly connect microgeometrical properties in limestone to spectral IP responses. The results from this study show that it is possible to recover

  5. The Limestone Glades And Barrens Of West Virginia

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Cedar glade, limestone barren, and glade woodland communities are reported from limestone terranes in the Ridge and Valley of northeastern West Virginia. The cedar...

  6. Recycling and valorisation of stainless steel slags

    Energy Technology Data Exchange (ETDEWEB)

    Van Dessel, J. [Belgian Building Research Institute, Brussels (Belgium)

    2001-07-01

    The project described in this paper involves the collaboration of eleven partners. The project aims to create a value-added product by recovering usable non-ferrous metals from the production of stainless steel and use the recycled slag as a secondary material for road construction and concrete applications. The objective of the project is to return the metal contained in the slag to stainless steel production, and to treat the non-metallic slag, perhaps by a metallurgical process based upon direct plasma technology, prior to use in a variety of processes. The project also aims to investigate the environmental characteristics of the slag, which is essential for it to be used as secondary material. The major challenge appears to be the development of an improved process for separating the slag from the metallic particles in order to avoid the frequent breakdowns and significant repairs associated with use of the material. It is expected that using magnetic and density-based separation processes will reduce the cost of maintenance by about 20 per cent. Results achieved to date, and economic factors impacting on feasibility, are also discussed. 2 tabs., 3 figs.

  7. Process-integrated slag treatment; Prozessintegrierte Schlackebehandlung

    Energy Technology Data Exchange (ETDEWEB)

    Koralewska, R.; Faulstich, M. [Technische Univ., Garching (Germany). Lehrstuhl fuer Wasserguete- und Abfallwirtschaft

    1998-09-01

    The present study compares two methods of washing waste incineration slag, one with water only, and one which uses additives during wet deslagging. The presented aggregate offers ideal conditions for process-integrated slag treatment. The paper gives a schematic description of the integrated slag washing process. The washing liquid serves to wash out the readily soluble constituents and remove the fines, while the additives are for immobilising heavy metals in the slag material. The study is based on laboratory and semi-technical trials on the wet chemical treatment of grate slag with addition of carbon dioxide and phosphoric acid. [Deutsch] Die dargestellten Untersuchungen beziehen sich auf den Vergleich zwischen einer Waesche der Muellverbrennungsschlacke mit Wasser und unter Zugabe von Additiven im Nassentschlacker. In diesem Aggregat bieten sich optimale Voraussetzungen fuer eine prozessintegrierte Schlackebehandlung. Die Durchfuehrung der integrierten Schlackewaesche wird schematisch gezeigt. Durch die Waschfluessigkeit sollen die leichtloeslichen Bestandteile ausgewaschen und die Feinanteile ausgetragen sowie durch die Additive zusaetzlich die Schwermetalle im Schlackematerial immobilisiert werden. Dazu erfolgten Labor- und halbtechnische Versuche zur nasschemischen Behandlung der Rostschlacken unter Zugabe von Kohlendioxid und Phosphorsaeure. (orig./SR)

  8. Use of slag for dye removal

    Energy Technology Data Exchange (ETDEWEB)

    Ramakrishna, K.R.; Viraraghavan, T. [Univ. of Regina, Saskatchewan (Canada). Faculty of Engineering

    1998-09-01

    Adsorption techniques employing activated carbon have been found to be reasonably effective in the removal of some of the ionic impurities in water. However, economic considerations may require the use of inexpensive sorbents which are either naturally available or available as waste products from manufacturing processes. Slag is one such waste product obtained during the manufacture of steel, and the present study investigates dye removal characteristics of slag from colored waters. Aqueous solutions prepared from commercial grade acid, basic, and disperse dyes were used in this study, and batch pH, kinetic, and isotherm studies were undertaken on a laboratory scale. The data were evaluated for applicability to the Langmuir, Freundlich, and BET isotherm models, and the removal capacity of slag was compared with that of granular activated carbon. Results indicated approximately 94% removal of the disperse dye by slag, compared with a removal of approximately 49% achieved by activated carbon. Removal of acid dyes (dyes containing anionic groups) was reasonably good (approximately 47 and 74%), though not as good as obtained using activated carbon (approximately 100%). Column studies were conducted with a disperse dye (nonionic, slightly soluble in water), and analysis of data showed a sorption capacity of 1.3 mg of disperse dye per gram of slag. However, effluent dye concentrations were found to be higher than the permissible levels for discharge to receiving waters.

  9. Clay and concrete brick

    CSIR Research Space (South Africa)

    Dlamini, MN

    2014-03-01

    Full Text Available are manufactured from raw clay as their primary ingredient. However concrete brick has also become a favoured material in recent times. This review will adumbrate the impact of these building materials on energy use and the environment....

  10. Clay goes patchy

    NARCIS (Netherlands)

    Kegel, W.K.; Lekkerkerker, H.N.W.

    2011-01-01

    Empty liquids and equilibrium gels have so far been only theoretical possibilities, predicted for colloids with patchy interactions. But evidence of both has now been found in Laponite, a widely studied clay.

  11. Analysis of limestones and dolomites by x-ray fluorescence spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wheeler, B.D.

    1999-07-01

    Sources of calcium are generally widespread and quite extensive. These sources are limestone, dolomite, marl, chalk, and oyster shell. Cement plants account for nearly half of the demand, while two hundred lime plants in the US and Puerto Rico consume about twenty five percent. Since the chemical composition of the limestone and other sources of calcium is critical in the cement and lime industry, particularly for the deleterious compounds such as sodium oxide, Na{sub 2}O, magnesium oxide, MgO, phosphorus pentoxide, P{sub 2}O{sub 5}, and potassium oxide, K{sub 2}O, accurate determinations are critical. Due to the tonnage per hour, these determinations must be made rapidly and accurately. X-ray fluorescence can thereby satisfy this need for accuracy and also precision. Production of lime is performed by calcining limestone or dolomite in which the industry is generally located and concentrated in the States of Michigan and Pennsylvania. The resulting product is quicklime, CaO, and hydrated lime, Ca(OH){sub 2}. Substantial amounts of quicklime is further processed into calcium carbide in order to produce acetylene gas. In this case, the determination of P{sub 2}O{sub 5} is critical since minor quantities of phosphorus in acetylene gas can cause premature explosions. Other uses for lime are well known in the treatment of water, the paper and pulp industry, and in the steel industry for the production of slag to remove impurities. Dolomitic lime is heavily utilized in the manufacture of magnesite refractories by reacting dolomitic lime with brines from the Michigan Basin to produce magnesium oxide, MgO, and calcium chloride, CaCl{sub 2}. Sample preparation for these materials usually is performed by grinding and pelletizing or fusion with lithium-tetra-borate, Li{sub 2}B{sub 4}O{sub 7}.

  12. X-ray fluoroscopic observation of slag foaming; Slag no awadachi gensho no x sen toshi kansatsu

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, Y.; Tokumitsu, N. [Nippon Steel Corp., Tokyo (Japan)

    2001-01-01

    Slag foaming caused by slag/metal reaction in a graphite crucible was observed with X-ray fluoroscopic apparatus in order to make clear the effect of bubble size on the foam height and the distribution of bubbles in slag. It was observed that the foam layer was formed when CO bubbles evolved at slag/metal interface became less than approximately 2mm in diameter. The foam height increased with the decrease of bubble size even in case of almost the same gas evolution rate. The size of bubbles decreased with the increase of iron oxide Content in slag and the decrease of sulphur content. It is considered that the bubbles become smaller when slag is wettable with metal. Therefore, the physical properties of slag/metal interface also affect the foam height besides the surface tension or viscosity of slag because they change the bubble size. (author)

  13. Hydrology of the southern parts of Okaloosa and Walton Counties, northwest Florida, with special emphasis on the upper limestone of the Floridan Aquifer

    Science.gov (United States)

    Barr, D.E.; Hayes, L.R.; Kwader, Thomas

    1985-01-01

    Increasing population in southern Okaloosa and Walton Counties have resulted in regional declines in the potentiometric surface of the upper limestone of the Floridan aquifer. Water levels have declined as much as 160 feet since 1940, and during peak seasonal demand as much as 190 feet. The Pensacola clay confining bed inhibits interchange of water between the Floridan aquifer and the surficial sand-and-gravel aquifer. The latter aquifer is of secondary importance as a public supply source. The Bucatunna clay confining bed separates the Floridan into upper and lower limestone units; the Floridan is underlain by the relatively impermeable Lisbon/Tallahatta confining unit. The Floridan aquifer dips south to the Gulf of Mexico, and is recharged by rainfall in northern Okaloosa and Walton Counties and in Alabama. The regional gradient of the potentiometric surface of the upper limestone, and presumably that of the lower limstone also, is south. Pumpage was variable in 1978; from 10.9 to 19.0 million gallons per day in January and June, respectively. Saline water in the upper limestone of the Floridan aquifer is less than 10 milligrams per liter inland but may be more than 150 milligrams per liter along the coast. Lower limestone water may exceed 250 milligrams per liter chloride. (USGS)

  14. Core size effect on the dry and saturated ultrasonic pulse velocity of limestone samples.

    Science.gov (United States)

    Ercikdi, Bayram; Karaman, Kadir; Cihangir, Ferdi; Yılmaz, Tekin; Aliyazıcıoğlu, Şener; Kesimal, Ayhan

    2016-12-01

    This study presents the effect of core length on the saturated (UPVsat) and dry (UPVdry) P-wave velocities of four different biomicritic limestone samples, namely light grey (BL-LG), dark grey (BL-DG), reddish (BL-R) and yellow (BL-Y), using core samples having different lengths (25-125mm) at a constant diameter (54.7mm). The saturated P-wave velocity (UPVsat) of all core samples generally decreased with increasing the sample length. However, the dry P-wave velocity (UPVdry) of samples obtained from BL-LG and BL-Y limestones increased with increasing the sample length. In contrast to the literature, the dry P-wave velocity (UPVdry) values of core samples having a length of 75, 100 and 125mm were consistently higher (2.8-46.2%) than those of saturated (UPVsat). Chemical and mineralogical analyses have shown that the P wave velocity is very sensitive to the calcite and clay minerals potentially leading to the weakening/disintegration of rock samples in the presence of water. Severe fluctuations in UPV values were observed to occur between 25 and 75mm sample lengths, thereafter, a trend of stabilization was observed. The maximum variation of UPV values between the sample length of 75mm and 125mm was only 7.3%. Therefore, the threshold core sample length was interpreted as 75mm for UPV measurement in biomicritic limestone samples used in this study.

  15. Electrochemistry of oxygen ion transport in slag

    Institute of Scientific and Technical Information of China (English)

    鲁雄刚; 丁伟中; 李福燊; 李丽芬; 周国治

    2002-01-01

    A systematic experiment relating to the electrochemistry of oxygen ion transport in slag has been studied in lab.An equivalent circuit has been used to describe ion transfer between metal and slag in this paper and a kinetic model with electrochemical characteristic representing oxygen ion immigration has been worked out.The different experimental phenomena can be explained generally by this model.It can be seen that the theoretical results are in good agreement with experiments.The comparison of experimental data with model calculation proved that the electrochemical model is right.

  16. Limitation of Sulfide Capacity Concept for Molten Slags

    Science.gov (United States)

    Jung, In-Ho; Moosavi-Khoonsari, Elmira

    2016-04-01

    The sulfide capacity concept has been widely used in pyrometallurgy to define sulfur removal capacities of slags. Typically, the sulfide capacity is considered to be a unique slag property depending only on temperature regardless of partial pressures of oxygen and sulfur. In the present study, it is demonstrated that sulfide capacities of slags in particular those of Na2O-containing slags can vary with partial pressures of oxygen and sulfur due to large solubility of sulfide in Na2O-containing slag systems.

  17. Limestone reaction in calcium aluminate cement–calcium sulfate systems

    Energy Technology Data Exchange (ETDEWEB)

    Bizzozero, Julien, E-mail: julien.bizzozero@gmail.com; Scrivener, Karen L.

    2015-10-15

    This paper reports a study of ternary blends composed of calcium aluminate cement, calcium sulfate hemihydrate and limestone. Compressive strength tests and hydration kinetics were studied as a function of limestone and calcium sulfate content. The phase evolution and the total porosity were followed and compared to thermodynamic simulation to understand the reactions involved and the effect of limestone on these binders. The reaction of limestone leads to the formation of hemicarboaluminate and monocarboaluminate. Increasing the ratio between sulfate and aluminate decreases the extent of limestone reaction.

  18. Distribution of Clay Minerals in Light Coal Fractions and the Thermal Reaction Products of These Clay Minerals during Combustion in a Drop Tube Furnace

    Directory of Open Access Journals (Sweden)

    Sida Tian

    2016-06-01

    Full Text Available To estimate the contribution of clay minerals in light coal fractions to ash deposition in furnaces, we investigated their distribution and thermal reaction products. The light fractions of two Chinese coals were prepared using a 1.5 g·cm−3 ZnCl2 solution as a density separation medium and were burned in a drop-tube furnace (DTF. The mineral matter in each of the light coal fractions was compared to that of the relevant raw coal. The DTF ash from light coal fractions was analysed using hydrochloric acid separation. The acid-soluble aluminium fractions of DTF ash samples were used to determine changes in the amorphous aluminosilicate products with increasing combustion temperature. The results show that the clay mineral contents in the mineral matter of both light coal fractions were higher than those in the respective raw coals. For the coal with a high ash melting point, clay minerals in the light coal fraction thermally transformed more dehydroxylation products compared with those in the raw coal, possibly contributing to solid-state reactions of ash particles. For the coal with a low ash melting point, clay minerals in the light coal fraction produced more easily-slagging material compared with those in the raw coal, playing an important role in the occurrence of slagging. Additionally, ferrous oxide often produces low-melting substances in coal ash. Due to the similarities of zinc oxide and ferrous oxide in silicate reactions, we also investigated the interactions of clay minerals in light coal fractions with zinc oxide introduced by a zinc chloride solution. The extraneous zinc oxide could react, to a small extent, with clay minerals in the coal during DTF combustion.

  19. The Öland limestone - A Swedish stone used for more than one thousand years

    Science.gov (United States)

    Schouenborg, Björn; Wickström, Linda; Mikaelsson, Jan

    2016-04-01

    landic limestone was intense even during Hanseatic times (14th to 17th centuries) and it can for example be found as floorings, mantel pieces, baptismal fonts in many German castles and manors. The literature tells us that export to Denmark, Poland and even southern Germany was intense during late medieval ages. This is because a lot of churches were built in Northern Europe at that time. However, the modern industrialised production had to wait until the early 20th century. Today, three companies quarry and process the limestones on a regular basis. They are primarily used for flooring, stairs, crazy stones for gardens, table tops, kitchen tops and, in some cases, also external cladding and paving. The latter only with more durable layers free of clay and open stylolites, so called "core stone" (direct translation). The presentation will show that the Öland limestone covers all aspects and requirements for being a Global heritage resource.

  20. Mineralogy and environmental geochemistry of historical iron slag, Hopewell Furnace National Historic Site, Pennsylvania, USA

    Science.gov (United States)

    Piatak, N.M.; Seal, R.R.

    2012-01-01

    The Hopewell Furnace National Historic Site in southeastern Pennsylvania, which features an Fe smelter that was operational in the 18th and 19th centuries, is dominated by three slag piles. Pile 1 slag, from the Hopewell Furnace, and pile 2 slag, likely from the nearby Cornwall Furnace, were both produced in cold-blast charcoal-fired smelters. In contrast, pile 3 slag was produced in an anthracite furnace. Ore samples from the nearby Jones and Hopewell mines that fed the smelter are mainly magnetite-rich with some sulfides (pyrite, chalcopyrite, sphalerite) and accessory silicates (quartz, garnet, feldspar, and clay minerals). Slag piles 1 and 2 are similar mineralogically containing predominantly skeletal and dendritic aluminian diopside and augite, skeletal forsteritic olivine, glass, rounded blebs of metallic Fe, and exotic quartz. Olivine is a major phase in all samples from pile 2, whereas it occurs in only a few samples from pile 1. Samples of the samples. Piles 1 and 2 are chemically similar; pile 1 slag overall contains the highest Fe 2O 3, K 2O and MnO, and the lowest MgO concentrations. Pile 3 slag is high in Al 2O 3, CaO and S, and low in Fe 2O 3, K 2O and SiO 2 compared to the other piles. In general, piles 1 and 2 are chemically similar to each other, whereas pile 3 is distinct - a conclusion that reflects their mineralogy. The similarities and differences among piles in terms of mineralogy and major element chemistry result from the different smelting conditions under which the slag formed and include the fuel source, the composition of the ore and flux, the type of blast (cold versus hot), which affects the furnace temperature, and other beneficiation methods.The three distinct slag piles at Hopewell are enriched in numerous trace elements, such as As (up to 12. mg/kg), Cd (up to 0.4. mg/kg), Co (up to 31.8. mg/kg), Cu (up to 647. mg/kg), Mn (up to 0.69. wt.%), Pb (up to 172. mg/kg) and Zn (up to 393. mg/kg), together with Fe (13.9. wt.%), when

  1. Valorization of BOF Steel Slag by Reduction and Phase Modification: Metal Recovery and Slag Valorization

    Science.gov (United States)

    Liu, Chunwei; Huang, Shuigen; Wollants, Patrick; Blanpain, Bart; Guo, Muxing

    2017-03-01

    Basic oxygen furnace (BOF) steel slag is a main byproduct in steelmaking, and its valorization is therefore of considerable interest, from a metal-recovery perspective and from a residue-utilization perspective. In the present study, the carbothermic reduction of BOF slag was investigated systematically. The reductions of Fe- and P-containing phases (i.e., oxide and compounds) are discussed. Effects of Al2O3 and SiO2 additions on the solidification microstructure and mineralogy associated with the reduction processes were also investigated. The formation and growth of the extracted metallic phase are discussed, and the mineralogy of the residue slag is determined. We conclude that by controlling the additions under a rapid cooling condition, it is possible to extract metallic iron as high-grade metal and simultaneously to utilize the remaining slag for construction applications.

  2. Impact of electro slag remelting on 14 109 steel properties

    Directory of Open Access Journals (Sweden)

    Pribulová A.

    2017-03-01

    Full Text Available The Electro Slag Remelting (ESR is one of the remelting processes in the field of metal refinery. In this process, the slag plays various roles, such as heat generation, protection of melt, and chemical refining. The main objective of the experiments described in this article was to identify the most appropriate slag composition for the electro slag remelting of the steel in order to achieve the chemical composition compliant with the standard applicable to the given steel, minimum sulphur content, minimum contents of oxide and sulphide inclusions, as well as mechanical properties corresponding to the standard applicable to the steel STN 14 109. Ten electrodes were remelted, whereas the remelting was carried out under 8 slags. The used slags containing 70% of CaF2 and 30% of Al2O3 with different addition of CaO, the slags consisted of the same components as previous slags, whereas the ratio of individual components was 1:1:1, and with SiO2 and MgO and slag without Al2O3. With regard to all the above mentioned facts, the slag types which may be regarded as the most appropriate for the STN 14 109 steel remelting are the basic slags containing 70% of CaF2 - 30% of Al2O3 with added 30 and 45 weight % of CaO.

  3. Research and development of blasting abrasive made of steelmaking slag

    Institute of Scientific and Technical Information of China (English)

    TANG Oujing

    2015-01-01

    This study focuses on the development of a new type of nonmetallic steelmaking slag abrasive.The performance,processing,and application of steelmaking slag as a nonmetallic abrasive are introduced.The chemical composition,hardness,crushing value,and particle gradation of steelmaking slag are analyzed.A processing method for steelmaking slag as a blasting abrasive is suggested and evaluated.Compared with conventional abrasives such as copper ore sand and cast iron shot,processed steelmaking slag exhibits similar performance and can satisfy abrasive technical requirements.The derusting effect provided by steelmaking slag for a ship deck can reach the Sa2.0 level,and its recyclability is higher than that of copper ore sand.The derusting performance of steelmaking slag is similar to that of copper ore,and it can thus be used in repairing ship decks.

  4. Separation of Iron Droplets From Titania Bearing Slag

    Institute of Scientific and Technical Information of China (English)

    WANG Ming-yu; LOU Tai-ping; ZHANG Li; SUI Zhi-tong

    2008-01-01

    Owing to smelting vanadium-titanium magnetite ore, the amount of iron entrainment in slag as droplets is far higher than that in conventional BF slag. However, the iron droplets can be easily settled by blowing air into the molten slag. The results show that more than 80% of iron droplets in titania bearing slag can be settled and separated after treatment. The temperature rise of molten slag during the oxidizing process and the decreased viscosity caused by the component change of slag as well as air stirring in slag both accelerate the iron droplets settling. The vanadium content in the settled iron droplets and the original iron droplets was obtained by chemical analysis. The possible reason for the increased vanadium in the settled iron droplets was discussed by thermodynamic principles.

  5. Characteristics and environmental aspects of slag: a review

    Science.gov (United States)

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

    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.

  6. Alteration in the Madera limestone and Sandia formation from core hole VC-1 Valles Caldera, New Mexico

    Science.gov (United States)

    Keith, Terry E. C.

    1988-06-01

    Core hole VC-1 penetrated the southwestern ring fracture zone of the 1.1 Ma Valles caldera and at a depth of 333 m intersected the top of the Paleozoic section including the Abo Formation, Madera Limestone, and Sandia Formation, reaching a total depth of 856 m. The Paleozoic rocks, which consist of thin-bedded limestone, siltstone, mudstone, sandstone, and local conglomerate, are overlain by volcanic rocks of the caldera moat that are less than 0.6 Ma. Diagenetic and at least three hydrothermal alteration stages were identified in the Madera Limestone and Sandia Formation. Diagenetic clay alteration was pervasive throughout the sedimentary rocks. Volcanic activity at 16.5 Ma and continuing through the formation of the Valles caldera resulted in high thermal gradients, which caused recrystallization of diagenetic clay minerals. Interstratified smectite-illite is the most diagnostic clay mineral throughout the section; structurally, the illite component in the ordered interstratified illite-smectite changes gradationally from 70% at the top of the Madera Limestone to 95% at the base of the section in the Sandia Formation. Pyrite that occurs as small clots and lenses as well as finely disseminated is interpreted as being of diagenetic origin, especially in organic-rich beds. Low permeability of much of the Paleozoic section precluded the deposition of hydrothermal minerals except in fractures and intergranular space in some of the more permeable sandstone and brecciated horizons. Three stages of hydrothermal mineral deposition are defined. Stage I is widespread and includes mainly chlorite, calcite, pyrite, and interstratified smectite-illite that was formed prior to caldera development at temperatures approximating 200°C. Stage II is characterized by quartz, sericite, and scarce sulfides deposited locally by fluids at approximately 275°C shortly before or at the time of early caldera-related volcanism. The Stage III hydrothermal event, associated with formation of

  7. Beneficiation of a low grade limestone sample

    Institute of Scientific and Technical Information of China (English)

    Rao Danda Srinivas; Vijayakumar Tadiparthi Venkata; Subba Rao Sripada; Bhaskar Raju Guntamadugu; Prabhakar Swarna

    2011-01-01

    Pilot scale column flotation studies were conducted on a low grade siliceous limestone ore.Silica content was reduced to less than 1% in the concentrate so that it became satisfactory for use in the paper or rubber industries.The limestone sample was crystalline and constituted primarily of calcite that contained quartz,feldspar,pyroxene,and biotite as gangue minerals.Quartz is the major silicate gangue whereas feldspar,pyroxene,and biotite exist in minor to trace quantities.Traces of pyrite were also observed within the sample.A reverse flotation process was adopted where the silicate gangue minerals were floated using two different commercial cationic collectors:Chem-750 F or Floatamine-D.The studies clearly suggest it is possible to produce a limestone concentrate assaying around 96-97% CaCO3 containing less than 1 % SiO2.The effect of feed flow rate,percent solids,froth depth,and wash water on the grade and recovery of the CaCO3 concentrate is discussed.

  8. Reatividade de uma escória de siderurgia em um latossolo vermelho distrófico Reactivity of a slag in a distrofic red latosol

    Directory of Open Access Journals (Sweden)

    R. M. Prado

    2004-02-01

    Full Text Available O presente trabalho objetivou estudar a reatividade de uma escória de siderurgia de aciaria, em diferentes frações granulométricas, aplicada em uma amostra de um Latossolo Vermelho distrófico, ácido, em condições de laboratório. Utilizou-se um fatorial 4 x 3 + 2 com quatro repetições, sendo quatro granulometrias (material retido entre as peneiras ABNT 5-10; 10-20; 20-50 e The present study investigated the reactivity of a slag from steelworks in different particle size fractions, applied on an acid dystrophic Red Latosol, under laboratory conditions, in a 4 x 3 + 2 factorial scheme in four replications. Four particle sizes (material retained in the ABNT 5-10; 10-20; 20-50, and < 50 sieves, three doses of slag (0.00, 5.04, and 10.08 t ha-1, corresponding to 0.00, 1.01, and 2.02 g in 0.40 dm³ of soil per cup and two control treatments (slag and dolomitic limestone in the corresponding dose to base saturation (V = 70 %, or either, 1.01 and 0.61 g per cup, respectively. The base saturation method was used for the definition of the doses, considering the CaCO3 equivalent value of slag and limestone, for the corresponding particle size fractions. The soil humidity was maintained at field capacity and incubated for three, six, and nine months. Grain size fractions of the slag affected differently the acidity of the soil. The fraction retained between the ABNT 5-10 sieves proved to be inefficient, while the fraction that passed through ABNT < 50 was the one with the greatest effect on acidity neutralization. The reactivity of retained slag particles in the intermediate sieves (ABNT 10-20 and 20-50 sieves was proportional to the effective values of the Brazilian legislation for lime. Therefore, the reactivity rate obtained for steelwork slag was: ABNT nº 5-10 = 0 %; 10-20 = 22 %; 20-50 = 58 % e < 50= 100 %.

  9. Elemental analysis of limestone samples from Obajana and Mfamosing limestone deposits, Nigeria, using nuclear techniques

    Energy Technology Data Exchange (ETDEWEB)

    Akpan, I.O. [Department of Physics, University of Calabar, Calabar, Cross River State (Nigeria); Amodu, A.E. [Science Laboratory Technology Department, Federal Polytechnic, Idah, Kogi State (Nigeria); Akpan, A.E., E-mail: anthonyakpan@yahoo.com [Department of Physics, University of Calabar, Calabar, Cross River State (Nigeria)

    2011-10-15

    Six limestone samples were picked from three different points at the Obajana and Mfamosing limestone deposits. The limestone samples were subjected to elemental analysis by Proton-Induced X-Ray Emission (PIXE) analysis. The samples were irradiated by a 4 mm diameter beam of protons with energy of 2.5 MeV and beam current of 0.2 nA for 0.9 ms. The analysis was carried out with the 1.7 MV Tandem accelerator at the Centre for Energy Research and Development (CERD), Ile-Ife, Osun State, Nigeria. The NIST geology standard NIST 278 was analysed for quality assurance. The elemental composition and concentration of 14 elements were determined in the two locations. Ten elements were found at the Obajana deposit while 13 elements were found at the Mfamosing deposits. The elements: Mg, Al, Ca and Mn do not differ much at both deposits while others differ. The major elements (Ca, Fe, Al, Si and K) present in the limestones were also found in airborne particulate matter studied by earlier researchers. These observations suggest that all particulate emissions and wastes from the Limestone deposit should be closely monitored to reduce their cumulative effects on both health and the environment

  10. Elemental analysis of limestone samples from Obajana and Mfamosing limestone deposits, Nigeria, using nuclear techniques.

    Science.gov (United States)

    Akpan, I O; Amodu, A E; Akpan, A E

    2011-10-01

    Six limestone samples were picked from three different points at the Obajana and Mfamosing limestone deposits. The limestone samples were subjected to elemental analysis by Proton-Induced X-Ray Emission (PIXE) analysis. The samples were irradiated by a 4mm diameter beam of protons with energy of 2.5 MeV and beam current of 0.2nA for 0.9 ms. The analysis was carried out with the 1.7MV Tandem accelerator at the Centre for Energy Research and Development (CERD), Ile-Ife, Osun State, Nigeria. The NIST geology standard NIST 278 was analysed for quality assurance. The elemental composition and concentration of 14 elements were determined in the two locations. Ten elements were found at the Obajana deposit while 13 elements were found at the Mfamosing deposits. The elements: Mg, Al, Ca and Mn do not differ much at both deposits while others differ. The major elements (Ca, Fe, Al, Si and K) present in the limestones were also found in airborne particulate matter studied by earlier researchers. These observations suggest that all particulate emissions and wastes from the Limestone deposit should be closely monitored to reduce their cumulative effects on both health and the environment.

  11. Mechanisms of phosphate removal from aqueous solution by blast furnace slag and steel furnace slag

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    We report the adsorption of phosphate and discuss the mechanisms of phosphate removal from aqueous solution by burst furnace slag (BFS) and steel furnace slag (SFS). The results show that the adsorption of phosphate on the slag was rapid and the majority of adsorption was completed in 5~10 min. The adsorption capacity of phosphate by the slag was reduced dramatically by acid treatment. The relative contribution of adsorption to the total removal of phosphate was 26%~28%. Phosphate adsorption on BFS and SFS follows the Freundlich isotherm, with the related constants ofk 6.372 and 1/n 1.739 for BFS, and ofk 1.705 and 1/n 1.718 for SFS. The pH and Ca2+ concentration were decreased with the addition of phosphate, suggesting the formation of calcium phosphate precipitation. At pH 2.93 and 6.93, phosphate was desorbed by about 36%~43% and 9%~11%, respectively.These results indicate that the P adsorption on the slag is not completely reversible and that the bond between the slag particles and adsorbed phosphate is strong. The X-ray diffraction (XRD) patterns of BFS and SFS before and after phosphate adsorption verify SFS is related to the formation of phosphate calcium precipitation and the adsorption on hydroxylated oxides. The results show that BFS and SFS removed phosphate nearly 100%, indicating they are promising adsorbents for the phosphate removal in wastewater treatment and pollution control.

  12. Microstructure characterisation of freeze linings formed in a copper slag cleaning slag

    Directory of Open Access Journals (Sweden)

    Jansson J.

    2015-01-01

    Full Text Available The initial growth rate of freeze linings on water-cooled elements submerged in molten iron silicate slag is fast. The freeze lining microstructure forming on water cooled steel surface in a high-silica, slag cleaning furnace slag of a direct-to-blister copper smelter is mostly glassy or amorphous. It contains 5-30 μm magnetite crystals, very small and larger copper droplets as well as small magnetite and silicate nuclei embedded in the glassy silica-rich matrix. Chemically the formed freeze linings are more silica-rich than the slag from which they were generated. Magnetite (spinel is the primary phase of the solidifying SCF slag but it does not form a continuous network through the freeze lining. Its strength is given by the intergranular silica-rich phase which initially is glassy or microcrystalline. Due to only partial slag reduction in the SCF process, large magnetite crystals are present in the freeze lining and seem to interact physically with copper droplets.

  13. Nieuwe wapens in de slag om groen

    NARCIS (Netherlands)

    Vreke, J.

    2010-01-01

    Groen verliest in en rond steden vaak de slag. Burgers vinden groene gebieden belangrijk, ze stimuleren beweging, bevorderen de integratie en maken huizen meer waard. Toch kiezen bestuurders uiteindelijk vaak toch voor ‘rood’ omdat dat geld en prestige oplevert. In deze bijdrage wordt verslag gedaan

  14. Integrated Characterization of DNAPL Source Zone Architecture in Clay Till and Limestone Bedrock

    DEFF Research Database (Denmark)

    Broholm, Mette Martina; Janniche, Gry Sander; Fjordbøge, Annika Sidelmann

    2014-01-01

    ); coring with quantitative subsample analysis, SudanIV test, and PID; and NAPL FACT FLUTe gave good insight in the source zone architecture in the clayey till. Surface geophysics with ground penetrating radar (GPR) and seismic reflection and refraction combined with geologic information supplemented...

  15. Physical, Chemical and Engineering Properties of Residual Limestone Soils and Clays.

    Science.gov (United States)

    1980-01-02

    the comprehensive publication issued by the U. S. Department of Agriculture entitled "Soil Classification, 7th Approxi- mation (1960)" contains not one...locations in the Tropics (Bahamas, Jamaica, Guadeloupe , Costa Rica, etc.). Examination of the data matrix indicated that chemical differences in the residual...Bahamas, Guadeloupe , Costa Rica and the Cayman Islands. The marked difference in overall composition of the major oxides was also seen when the

  16. Recent advances in understanding physical properties of metallurgical slags

    Science.gov (United States)

    Min, Dong Joon; Tsukihashi, Fumitaka

    2017-01-01

    Present-day knowledge of the structure and physical properties of metallurgical slags is summarized to address structure-property and inter-property relationships. Physical properties of slags including viscosity, electrical conductivity, and surface tension is reviewed focusing on the effect of slag structure, which is comprehensively evaluated using FT-IT, Raman, and MAS-NMR spectroscopy. The effect of the slag composition on slag structure and property is reviewed in detail: Compositional effect encompasses traditional concepts of basicity, network-forming behaviors of anions, and secondary impact of network-modifying cations. Secondary objective of this review is elucidating the mutual relationship between physical properties of slags. For instance, the relationship between slag viscosity and electrical conductivity is suggested by Walden's rule and discussed based on the experimental results. Slag foaming index is also introduced as a comprehensive understanding method of physical properties of slags. The dimensional analysis was made to address the effect of viscosity, density, and surface tension on the foaming index of slags.

  17. Synthesis and heavy metal immobilization behaviors of slag based geopolymer.

    Science.gov (United States)

    Yunsheng, Zhang; Wei, Sun; Qianli, Chen; Lin, Chen

    2007-05-08

    In this paper, two aspects of studies are carried out: (1) synthesis of geopolymer by using slag and metakaolin; (2) immobilization behaviors of slag based geopolymer in a presence of Pb and Cu ions. As for the synthesis of slag based geopolymer, four different slag content (10%, 30%, 50%, 70%) and three types of curing regimes (standard curing, steam curing and autoclave curing) are investigated to obtain the optimum synthesis condition based on the compressive and flexural strength. The testing results showed that geopolymer mortar containing 50% slag that is synthesized at steam curing (80 degrees C for 8h), exhibits higher mechanical strengths. The compressive and flexural strengths of slag based geopolymer mortar are 75.2 MPa and 10.1 MPa, respectively. Additionally, Infrared (IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques are used to characterize the microstructure of the slag based geopolymer paste. IR spectra show that the absorptive band at 1086 cm(-1) shifts to lower wave number around 1007 cm(-1), and some six-coordinated Als transforms into four-coordination during the synthesis of slag based geopolymer paste. The resulting slag based geopolymeric products are X-ray amorphous materials. SEM observation shows that it is possible to have geopolymeric gel and calcium silicate hydrate (C-S-H) gel forming simultaneously within slag based geopolymer paste. As for immobilization of heavy metals, the leaching tests are employed to investigate the immobilization behaviors of the slag based geopolymer mortar synthesized under the above optimum condition. The leaching tests show that slag based geopolymer mortar can effectively immobilize Cu and Pb heavy metal ions, and the immobilization efficiency reach 98.5% greater when heavy metals are incorporated in the slag geopolymeric matrix in the range of 0.1-0.3%. The Pb exhibits better immobilization efficiency than the Cu in the case of large dosages of heavy metals.

  18. Magnificent Clay Murals

    Science.gov (United States)

    Kirker, Sara Schmickle

    2007-01-01

    Each August, third grade artists at Apple Glen Elementary in Bentonville, Arkansas, start the school year planning, creating, and exhibiting a clay relief mural. These mural projects have helped students to acquire not only art knowledge and techniques, but an even more important kind of knowledge: what it means to plan and successfully complete a…

  19. Rattles of Clay.

    Science.gov (United States)

    Banning, Donna

    1983-01-01

    Using the rattles of Native American cultures as inspiration, students used pinching, coiling, and slab and molding techniques to form the bodies of rattles and clay pellets for sound. Surface decoration included glazed and unglazed areas as well as added handles, feathers, and leather. (IS)

  20. Physical Properties of Latvian Clays

    OpenAIRE

    2012-01-01

    Physical and chemical properties of clays mostly depends on its mineral and chemical composition, particle size and pH value. The mutual influence of these parameters is complex. Illite is the most abundant clay mineral in Latvia and usually used in building materials and pottery. The viscosity and plasticity of Latvian clays from several deposits were investigated and correlated with mineral composition, particle size and pH value. Fractionated and crude clay samples were used. The p...

  1. Hydrogen Chloride Reaction with Lime and Limestone

    DEFF Research Database (Denmark)

    Erik Weinell, Claus; Jensen, Peter I.; Dam-Johansen, Kim

    1992-01-01

    The capacity of solid slaked lime and limestone for binding HCl from a gas phase has been investigated in the temperature range 60-1000 °C. The binding capacity is largest in the range 500-600 °C. However, for slaked lime in the presence of water, a large binding capacity is observed also below 150...... °C. This is ascribed to the formation of a partially liquid product phase. At temperatures exceeding 500 °C the binding capacity is limited by chemical equilibrium between gas and solid. For the range of properties studied the binding capacity is independent of particle size and only depends slightly...

  2. Clay Animals and Their Habitats

    Science.gov (United States)

    Adamson, Kay

    2010-01-01

    Creating clay animals and their habitats with second-grade students has long been one of the author's favorite classroom activities. Students love working with clay and they also enjoy drawing animal homes. In this article, the author describes how the students created a diorama instead of drawing their clay animal's habitat. This gave students…

  3. Using of Local Limestone as Aggregate in Concrete Mixture

    Directory of Open Access Journals (Sweden)

    Dr.Muyasser M. Jomaa'h

    2012-03-01

    Full Text Available This research deals with the field investigations and construction properties for using limestone as a lightweight course aggregate in concrete mixture in stead of normal coarse aggregate. Concrete cubes samples have been prepared with dimensions of 150*150*150 mm according to ASTM. For these samples the normal coarse aggregate was replaced by 100% coarse crushed limestone. Three types of limestone which were used (Al-Sinea, Makhool and Himreen, it was found that the Al-Sinea type of limestone gave a good combination (fcu =32.11MPa without admixtures. The obtained results showed a suitable reduction in dead loads of structural elements and cost. Accordingly, the usage of limestone will improve the structural applications and concrete mix properties to attain economic viability. These above results make limestone as a good alternative of normal coarse aggregate

  4. A review of WIPP (Waste Isolation Pilot Plant) repository clays and their relationship to clays of adjacent strata

    Energy Technology Data Exchange (ETDEWEB)

    Krumhansl, J.L.; Kimball, K.M.; Stein, C.L.

    1990-12-01

    The Salado Formation is a thick evaporite sequence located in the Permian Delaware Basin of southeastern New Mexico. This study focuses on the intense diagenetic alteration that has affected the small amounts of clay, feldspar, and quartz washed into the basin during salt deposition. These changes are of more than academic interest since this formation also houses the WIPP (Waste Isolation Pilot Plant). Site characterization concerns warrant compiling a detailed data base describing the clays in and around the facility horizon. An extensive sampling effort was undertaken to address these programmatic issues as well as to provide additional insight regarding diagenetic mechanisms in the Salado. Seventy-five samples were collected from argillaceous partings in halite at the stratigraphic level of the Waste Isolation Pilot Plant (WIPP). These were compared with twenty-eight samples from cores of the Vaca Triste member of the Salado, a thin clastic unit at the top of the McNutt potash zone, and with a clay-rich sample from the lower contact of the Culebra Dolomite (in the overlying Rustler Formation). These settings were compared to assess the influence of differences in brine chemistry (i.e., halite and potash facies, normal to hypersaline marine conditions) and sediment composition (clays, sandy silt, dolomitized limestone) on diagenetic processes. 44 refs., 11 figs., 5 tabs.

  5. Reduction Kinetics of Electric Arc Furnace Oxidizing Slag by Al-Fe Alloy

    Science.gov (United States)

    Lee, Jaehong; Oh, Joon Seok; Lee, Joonho

    2016-09-01

    Effects of temperature and slag basicity on the reduction rate of iron oxide in molten synthetic electric arc furnace oxidizing slag by Al-40 wt.%Fe alloy was investigated. An alloy sample was dropped into molten slag in an MgO crucible. When the initial slag temperature was 1723 K, there was no reduction. However, when the initial slag temperature was 1773 K and the slag basicity was 1.1, the reduction was initiated and the temperature of the slag rapidly increased. When the slag basicity was 1.1, increasing the initial slag temperature from 1773 K to 1823 K increases the reaction rate. As the slag basicity increased from 1.1 to 1.4 at 1773 K, the reaction rate increased. From SEM analysis, it was found that an Al2O3 or a spinel phase at the slag-metal interface inhibited the reaction at a lower temperature and a lower slag basicity.

  6. Leaching of heavy metals from steelmaking slags

    Directory of Open Access Journals (Sweden)

    Gomes, J. F. P

    2006-12-01

    Full Text Available Leaching tests with EAF and Ladle slags were performed, using a flow through test and the standard batch test DIN 38414-S4. The previous method was used to simulate the leaching behaviour of steel slags under landfill. The chemical analysis of the leachates during this period shows, in general, for both types of slag, an increase of heavy metal releases with ageing. Standard test method DIN 38414-S4 was used to evaluate leachability of heavy metals by water in unprocessed slags. After more than one year of trials, slag samples submitted to these trials presented very low total leaching levels. The most extracted elements are calcium and magnesium. Nevertheless, in flow-through test, calcium and magnesium leached from solid slags are below 0.5% and all other metals below 0.1%. Leachates obtained with DIN 38414-S4 present, as expected, higher leaching values; however, these are inferior to 5 % (Ca and 1% (other elements.

    Este articulo contiene los resultados obtenidos en ensayos de lixiviación de escorias de acero (horno electrico y cuchara ejecutados siguiendo la metodologia de flujo dinámico así como el ensayo normalizado DIN 38414-S4. El primer ensayo intenta simular el comportamiento de lixiviación de las escorias en vertedero. Para las escorias ensayadas se han complementado los ensayos con el análisis químico de los lixiviados y se ha verificado un aumento de la liberación de metales pesados. El ensayo DIN 38414-S4 se ha utilizado para evaluar la lixiviación por agua de metales pesados, en muestras de escorias originales. Despues de un año de ensayos, se han observado niveles muy bajos de lixiviación. Los elementos mas lixiviados han sido calcio y magnesio. No obstante, en los ensayos de flujo dinámico, el calcio y el magnesio lixiviados de las escorias sólidas era menor de 0,5% y el resto de los otros metales era inferior a 0,1%. Los lixiviados obtenidos con el ensayo DIN 38414-S4 presentan, como era de esperar, valores

  7. Clay membrane made of natural high plasticity clay:

    DEFF Research Database (Denmark)

    Foged, Niels; Baumann, Jens

    1999-01-01

    Leachate containment in Denmark has throughout the years been regulated by the DIF Recommendation for Sanitary Landfill Liners (DS/R4669. It states that natural clay deposits may be used as membrane material provided the membrane and drainage system contains at least 95% of all leachate created...... into account advective ion transport as well as diffusion. Clay prospecting for clays rich in smectite has revealed large deposits of Tertiary clay of very high plasticity in the area around Rødbyhavn on the Danish island of Lolland. The natural clay contains 60-75% smectite, dominantly as a sodium......-type. The clay material has been evaluated using the standardized methods related to mineralogy, classification, compaction and permeability, and initial studies of diffusion properties have been carried out. Furthermore, at a test site the construction methods for establishing a 0.15-0.3 m thick clay membrane...

  8. Elemental analysis of limestone samples from Ewekoro limestone deposit in southwest Nigeria

    Science.gov (United States)

    Obiajunwa, E. I.; Nwachukwu, J. I.

    2000-10-01

    Limestone samples of different colours from Ewekoro limestone deposit in Ogun State, Nigeria were subjected to elemental analysis by proton-induced X-ray emission (PIXE) and proton-induced gamma-ray emission (PIGME) techniques. The irradiation was by 2.5 MeV proton beams from the ion beam analysis (IBA) facility of the 3 MV Van de Graaff accelerator at the Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights. Elemental composition and concentrations of 22 major, minor and trace elements were determined. The NIST geological standard, NBS278, was analysed for quality assurance. The concentrations of the major elements (Ca, Fe, K and Al) are similar in the samples while the other major elements differed. Calcium accounts for about 38%, giving 86.8% CaCO 3 content in the limestones. The major elements (Al, Ca, Fe, Si, S and K), present in the limestones, were also found to be enriched in airborne particulate matter studied by earlier workers, thus confirming cement dust as the major contributor to the particulate matter within and around cement factories.

  9. Rock mass characterization for tunnels in the Copenhagen limestone

    DEFF Research Database (Denmark)

    Foged, Niels Nielsen; Jakobsen, Lisa; Jackson, Peter

    2007-01-01

    Tunnels in Copenhagen are drilled through highly anisotropic limestone comprising alternating strongly lithified and less lithified parts. The mass quality of the limestone is usually defined from fracture spacing registered in core samples. The deposit is, however, affected destructively by dril...... by drilling activity yielding a low Rock Quality Designation RQD. In-situ observations of the limestone in excavations or televiewer logs reveal only few natural discontinuities compared to core logging, indicating a very good suitability for tunneling....

  10. Limestone types used from the classic Karst region in Slovenia

    Science.gov (United States)

    Kramar, Sabina; Mirtič, Breda; Mladenović, Ana; Rožič, Boštjan; Bedjanič, Mojca; Kortnik, Jože; Šmuc, Andrej

    2014-05-01

    The paper presents a variety of limestones from the Karst Region that is one of the most interesting areas containing reserves of natural stones in Slovenia. The region is mainly composed of Cretaceous shallow-water limestone, with the most common type currently excavated being the rudist limestone of the Lipica Formation, which dates to the Santonian to Campanian. Limestones of this formation are mainly represented by a light grey, thick-bedded to massive Lipica limestone rich in (largely fragmented) rudists. Rudist shells can be either relatively well preserved (such as in Lipica Fiorito quarried limestone) or almost completely disintegrated and intensively endolitised (Lipica Unito quarried limestone). Beside the Lipica Formation, natural stone types have been excavated from two other formations or members in the Karst region: the Repen Formation (Repen and Kopriva limestones), and the Tomaj Limestone (dark, laminated limestone within the Lipica Formation). As documented, the region has been associated with the quarrying and processing of stone at least for over two thousand years, i.e. since the Roman period. Although a large number of quarries in all mentioned formations are documented in the Karst region, many are inactive nowadays. Some of the quarries are declared as geological monuments of national importance or officially protected as a natural monument. Karst limestones are considered the highest quality calcareous natural stones in Slovenia. They are characterised by high density, low water absorption and low open porosity; consequently they also exhibit high frost and salt resistance as well as high compressive and flexural strength. Besides in the Karst region and other parts of Slovenia, the Karst limestones were used in the construction of several important buildings and monuments in many other European Countries, and worldwide. Nowadays, they are most commonly used in the construction of façade cladding, pavements, window sills, staircases, indoor

  11. Rock mass characterization for tunnels in the Copenhagen limestone

    DEFF Research Database (Denmark)

    Foged, Niels Nielsen; Jakobsen, Lisa; Jackson, Peter;

    2007-01-01

    Tunnels in Copenhagen are drilled through highly anisotropic limestone comprising alternating strongly lithified and less lithified parts. The mass quality of the limestone is usually defined from fracture spacing registered in core samples. The deposit is, however, affected destructively by dril...... by drilling activity yielding a low Rock Quality Designation RQD. In-situ observations of the limestone in excavations or televiewer logs reveal only few natural discontinuities compared to core logging, indicating a very good suitability for tunneling....

  12. Investigation on the Potentials of Cupola Furnace Slag in Concrete

    Directory of Open Access Journals (Sweden)

    Stephen Adeyemi Alabi

    2013-12-01

    Full Text Available The compressive strength of the concrete designed using blast cupola furnace slag and granulated cupola slag as a coarse aggregate and partial replacement for cement was investigated. A series of experimental studies were conducted involve concrete production in two stages. The first stage comprised of normal aggregate concrete (NAC produced with normal aggregates and 100% ordinary Portland cement (OPC. Meanwhile, the second stage involved production of concrete comprising of cupola furnace slag an aggregates with 100% ordinary Portland cement (OPC and subsequently with 2%, 4%, 6%, 8% and 10% cementitious replacement with granulated cupola furnace slag that had been grounded and milled to less than 75 µm diameter. The outcomes of compressive strength test conducted on the slag aggregate concrete (SAC with and without granulated slag cementitious replacement were satisfactory compared to normal aggregate concretes (NAC.

  13. The hydraulic potential of high iron bearing steel slags

    Science.gov (United States)

    Ionescu, Denisa Virginia

    The incorporation of additives to the clinker or to the raw materials stream is a common practice in cement manufacture. However, steel slag, unlike its ironmaking parent the blast furnace slag, it is not a conventional admixture for cement. Currently most steel slags are slow cooled rendering stable crystalline compounds with minor hydraulic value. Nevertheless, if steel slags would be quenched and granulated, the resulting glassy product might display increased hydration and strength development potential. The use of steel slag in cement could contribute to important savings for both cement and steelmaking industries and provide a solution for the environmental problems linked to CO2 emissions and costs of transport and disposal. The purpose of this research is to explore the thermodynamics and kinetics of steel slag hydration in an effort to produce a cement additive, or a more promising material of near Portland cement composition. An important criteria used in the assessment of slags as potential cements is the presence of a glassy phase. At present, it is not very clear why glass enhances the hydration process. However, it is known that the free energy of formation for glasses is less than for crystals so that glasses are easier to hydrate compared to crystalline materials. In the particular case of steel slag, the glassy phase would have to contain high amounts of iron. Steel slags are known to display iron levels approximately 10 times higher than Portland cement and commonly used blast furnace slags. However, the effect of high Fe2O3 levels on the setting and strengthening of cement paste is not clearly understood due to the fact that most cement additives do not present this characteristic. The present work looks at the progress made in recycling steel slag as cement additive, the complexity of the hydration process in slags, the possibilities of improving the hydration potential of slags at laboratory and industrial level, and the problems that still

  14. Optimization of Blended Mortars Using Steel Slag Sand

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new kind of mortar made of ground granulated blast-furnace slag (GGBFS), gypsum,clinker and steel slag sand (<4.75 mm) was developed. The ratio of steel slag sand to GGBFS was 1:1 and the amount of gypsum was 4% by weight while the dosage of clinker ranged from 0% to 24%. The optimization formulation of such mortar was studied. The content of steel slag sand should be less than 50% according to the volume stability of blended mortar, and the dosage of clinker is about 10% based on the strength development.Besides strength, the hydration heat, pore structure and micro pattern of blended mortar were also determined.The experimental results show the application of steel slag sand may reduce the dosage of cement clinker and increase the content of industrial waste product such as GGBFS, and the clinker is also a better admixture for blended mortar using steel slag sand.

  15. Improving Beneficiation of Copper and Iron from Copper Slag by Modifying the Molten Copper Slag

    Directory of Open Access Journals (Sweden)

    Zhengqi Guo

    2016-04-01

    Full Text Available In the paper, a new technology was developed to improve the beneficiation of copper and iron components from copper slag, by modifying the molten slag to promote the mineralization of valuable minerals and to induce the growth of mineral grains. Various parameters, including binary basicity, dosage of compound additive, modification temperature, cooling rate and the end point temperature of slow cooling were investigated. Meanwhile, optical microscope, scanning electron microscope and energy dispersive spectrometer (SEM-EDS was employed to determine the mineralogy of the modified and unmodified slag, as well as to reveal the mechanisms of enhancing beneficiation. The results show that under the proper conditions, the copper grade of rougher copper concentrate was increased from 6.43% to 11.04%, iron recovery of magnetic separation was increased significantly from 32.40% to 63.26%, and other evaluation indexes were changed slightly, in comparison with unmodified copper slag. Moreover, matte and magnetite grains in the modified slag aggregated together and grew obviously to the mean size of over 50 μm, resulting in an improvement of beneficiation of copper and iron.

  16. Behavior of slag foaming caused by blowing gas in molten slags

    Energy Technology Data Exchange (ETDEWEB)

    Wu, K.

    2000-10-01

    The relationship between the height of foaming slag and blowing gas flow rate has been investigated at different temperature and with additives such as coal, coke, graphite and CaO, in order to understand the foaming phenomenon in most metallurgical processes comprehensively. On the basis of experimental results, the regressed foam behavior equations ({delta}=b(center dot)V{sup m}) were obtained. Those correlation coefficients were in range from 0.995 to 0.999. It means that the foam behavior equation can be used to describe foaming ability of the slag foaming caused by blowing gas quantitatively. The foaming index {sigma} is only a limited case for of the foam behavior equation and can be used only at high temperature and without additives for the foaming phenomenon caused by blowing gas. It was found also that the large carbonaceous particles could decrease the height of foaming slag, however the fine carbonaceous and CaO powder could increase it. The basicity of the slag affects the height of foaming slag. (author)

  17. Geology and Refractory Clay Deposits of the Haldeman and Wrigley Quadrangles, Kentucky

    Science.gov (United States)

    Patterson, Sam H.; Hosterman, John W.; Huddle, John Warfield

    1962-01-01

    The Haldeman and Wrigley 7th-minute quadrangles are near the western edge of the eastern Kentucky coal field and cover an area of approximately 117 square miles in parts of Carter, Rowan, Elliott, and Morgan Counties, Ky. The rocks exposed in the two quadrangles are of Early and Late Mississippian and Early and Middle Pennsylvanian age. The Mississippian rocks are composed of the thick Brodhead formation, which consists of siltstone and shale, and eleven thin marine limestone and shale formations, having an aggregate thickness of about 150 feet. The Lee and Breathitt formations, of Pennsylvanian age, consist of sandstone, siltstone, and shale; they also contain thin beds of coal and several beds of underclay, including the economically important Olive Hill clay bed of Crider, 1913. Pennsylvanian rocks include beds of both continental and marine origin. The eleven thin Mississippian formations and the upper-most part of the thick Brodhead formation are truncated by a prominent unconformity on which rocks of Pennsylvanian age rest. The rocks occupy a region of gentle dips between the Cincinnati arch and the Appalachian Mountains. Refractory clay deposits are in the Olive Hill clay bed, which occurs in the lower part of the Lee formation. The Olive Hill clay bed is discontinuous and consists of a series of irregularly shaped lenses. The bed is approximately two-thirds semifiint clay and one-third flint clay, and it contains minor amounts of plastic clay. Some of the flint clay is nearly pure kaolinite, but the semi flint and plastic clay consists of mixtures of kaolinite, illite, and mixed-layer clay minerals. The structure of the kaolinite ranges from highly crystalline to very poorly crystalline 'fireclay' type. The degree of crystallinity of the kaolinite and the hardness of the clay vary inversely with the amount of illite and mixed-layer clay minerals present. The nearly pure kaolinite is believed to have formed by the removal of alkalies and some silica fram

  18. Electrochemical Method to Accelerate Metal-Slag Reaction

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The electrochemical nature of reaction between melt and slag in a closed system was worked out. Experimental results demonstrated that both the rate and reaction extent increase when the electronic conductor or voltage was applied between melt and slag. The bigger the contact area of the conductor with melts is, the faster the reaction rate is. With the increase of applied voltage which is beneficial for electron's migration between metal and slags, the rate and extent of reaction increase.

  19. Potential of Electrical Resistivity Tomography to Detect Fault Zones in Limestone and Argillaceous Formations in the Experimental Platform of Tournemire, France

    Science.gov (United States)

    Gélis, C.; Revil, A.; Cushing, M. E.; Jougnot, D.; Lemeille, F.; Cabrera, J.; de Hoyos, A.; Rocher, M.

    2010-11-01

    The Experimental platform of Tournemire (Aveyron, France) developed by IRSN (French Institute for Radiological Protection and Nuclear Safety) is located in a tunnel excavated in a clay-rock formation interbedded between two limestone formations. A well-identified regional fault crosscuts this subhorizontal sedimentary succession, and a subvertical secondary fault zone is intercepted in the clay-rock by drifts and boreholes in the tunnel at a depth of about 250 m. A 2D electrical resistivity survey was carried out along a 2.5 km baseline, and a takeout of 40 m was used to assess the potential of this method to detect faults from the ground surface. In the 300 m-thick zone investigated by the survey, electrical resistivity images reveal several subvertical low-resistivity discontinuities. One of these discontinuities corresponds to the position of the Cernon fault, a major regional fault. One of the subvertical conductive discontinuities crossing the upper limestone formation is consistent with the prolongation towards the ground surface of the secondary fault zone identified in the clay-rock formation from the tunnel. Moreover, this secondary fault zone corresponds to the upward prolongation of a subvertical fault identified in the lower limestone using a 3D high-resolution seismic reflection survey. This type of large-scale electrical resistivity survey is therefore a useful tool for identifying faults in superficial layers from the ground surface and is complementary to 3D seismic reflection surveys.

  20. Reduction of chromium oxide from slags

    Directory of Open Access Journals (Sweden)

    Gutiérrez-Paredes, J.

    2005-12-01

    Full Text Available Experimental and theoretical work were performed to estimate the effect of slag basicity and amount of reducing agents on the reduction of chromium oxide from the slag which interacted with molten steel at 1,600 °C. The slag system contained CaO, MgO, SiO2, CaF2 and Cr2O3 together with Fe-alloys (Fe-Si and Fe-Si-Mg. The CaF2 and MgO contents in the slags were 10 mass % each; Cr2O3 was 25%. The amount of the ferroalloys ranged from 12.5 to 50 g per 100 g of slag. The (CaO+MgO/SiO2 ratio was held at 1 and 2. The Cr yield was determined using both Fe-alloys as reducing agents. Some estimations were made to determine the theoretical effect of temperature, slag basicity, (CaO+MgO/SiO2, and amount of reducing agents in the slag on the chromium recovery. The FACT (Facility for the Analysis of Chemical Thermodynamics computational package is used to determine the equilibrium between the slag and molten steel.

    En el presente trabajo se realiza un estudio teórico y experimental para determinar el efecto de la basicidad de la escoria y la cantidad de agentes reductores sobre la reducción de óxidos de cromo contenidos en la escoria, la cual está en contacto con acero líquido a 1.600 °C. La escoria se prepara con los reactivos CaO, MgO, SiO2, CaF2 y ferroaleaciones (Fe-Si y Fe-Si-Mg. Los contenidos de CaF2 y MgO en la escoria son de 10 %, cada uno, y el de Cr2O3 es 25 %. La cantidad de la ferroaleación varía de 12,5 a 50 g por cada 100 g de escoria. La relación (CaO+MgO/SiO2 tiene los valores de 1 y 2. Se determina la eficiencia de recuperación de cromo empleando los dos tipos de ferroaleaciones. Se realizaron cálculos para determinar el efecto teórico de la temperatura, la basicidad de la escoria, (CaO+MgO/SiO2, y la cantidad de agentes reductores sobre la reducci

  1. Thermochemistry of calcium oxide and calcium hydroxide in fluoride slags

    Science.gov (United States)

    Chattopadhyay, S.; Mitchell, A.

    1990-08-01

    Calcium oxide activity in binary CaF2-CaO and ternary CaF2-CaO-Al2O3 and CaF2-CaO-SiO2 slags has been determined by CO2-slag equilibrium experiments at 1400 °C. The carbonate ca-pacity of these slags has also been computed and compared with sulfide capacity data available in the literature. The similarity in trends suggests the possibility of characterizing carbonate capacity as an alternative basicity index for fluoride-base slags. Slag-D2O equilibrium experi-ments are performed at 1400°C with different fluoride-base slags to determine water solubility at two different partial pressures of D2O, employing a new slag sampling technique. A novel isotope tracer detection technique is employed to analyze water in the slags. The water solubility data found show higher values than the previous literature data by an order of magnitude but show a linear relationship with the square root of water vapor partial pressure. The activity of hydroxide computed from the data is shown to be helpful in estimating water solubility in in-dustrial electroslag remelting (ESR) slags.

  2. Chemical, Mineralogical, and Morphological Properties of Steel Slag

    Directory of Open Access Journals (Sweden)

    Irem Zeynep Yildirim

    2011-01-01

    Full Text Available Steel slag is a byproduct of the steelmaking and steel refining processes. This paper provides an overview of the different types of steel slag that are generated from basic-oxygen-furnace (BOF steelmaking, electric-arc-furnace (EAF steelmaking, and ladle-furnace steel refining processes. The mineralogical and morphological properties of BOF and electric-arc-furnace-ladle [EAF(L] slag samples generated from two steel plants in Indiana were determined through X-Ray Diffraction (XRD analyses and Scanning Electron Microscopy (SEM studies. The XRD patterns of both BOF and EAF(L slag samples were very complex, with several overlapping peaks resulting from the many minerals present in these samples. The XRD analyses indicated the presence of free MgO and CaO in both the BOF and EAF(L slag samples. SEM micrographs showed that the majority of the sand-size steel slag particles had subangular to angular shapes. Very rough surface textures with distinct crystal structures were observed on the sand-size particles of BOF and EAF(L slag samples under SEM. The characteristics of the steel slag samples considered in this study are discussed in the context of a detailed review of steel slag properties.

  3. Evaluation of copper slag blast media for railcar maintenance

    Science.gov (United States)

    Sagers, N. W.; Finlayson, Mack H.

    1989-01-01

    Copper slag was tested as a blasting substitute for zirconium silicate which is used to remove paint from railroad cars. The copper slag tested is less costly, strips paint faster, is produced near the point of need, provides a good bonding surface for paint, and permits the operator to work in a more comfortable position, i.e., standing nearly erect instead of having to crouch. Outdoor blasting with the tested Blackhawk (20 to 40 mesh) copper slag is also environmentally acceptable to the State of Utah. Results of tests for the surface erosion rate with copper slag blasting are included.

  4. Evaluation of copper slag blast media for railcar maintenance

    Science.gov (United States)

    Sagers, N. W.; Finlayson, Mack H.

    1989-06-01

    Copper slag was tested as a blasting substitute for zirconium silicate which is used to remove paint from railroad cars. The copper slag tested is less costly, strips paint faster, is produced near the point of need, provides a good bonding surface for paint, and permits the operator to work in a more comfortable position, i.e., standing nearly erect instead of having to crouch. Outdoor blasting with the tested Blackhawk (20 to 40 mesh) copper slag is also environmentally acceptable to the State of Utah. Results of tests for the surface erosion rate with copper slag blasting are included.

  5. Durability of Alkali Activated Blast Furnace Slag

    Science.gov (United States)

    Ellis, K.; Alharbi, N.; Matheu, P. S.; Varela, B.; Hailstone, R.

    2015-11-01

    The alkali activation of blast furnace slag has the potential to reduce the environmental impact of cementitious materials and to be applied in geographic zones where weather is a factor that negatively affects performance of materials based on Ordinary Portland Cement. The scientific literature provides many examples of alkali activated slag with high compressive strengths; however research into the durability and resistance to aggressive environments is still necessary for applications in harsh weather conditions. In this study two design mixes of blast furnace slag with mine tailings were activated with a potassium based solution. The design mixes were characterized by scanning electron microscopy, BET analysis and compressive strength testing. Freeze-thaw testing up to 100 freeze-thaw cycles was performed in 10% road salt solution. Our findings included compressive strength of up to 100 MPa after 28 days of curing and 120 MPa after freeze-thaw testing. The relationship between pore size, compressive strength, and compressive strength after freeze-thaw was explored.

  6. Clay at Nili Fossae

    Science.gov (United States)

    2006-01-01

    This image of the Nili Fossae region of Mars was compiled from separate images taken by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) and the High-Resolution Imaging Science Experiment (HiRISE), two instruments on NASA's Mars Reconnaissance Orbiter. The images were taken at 0730 UTC (2:30 a.m. EDT) on Oct. 4, 2006, near 20.4 degrees north latitude, 78.5 degrees east longitude. CRISM's image was taken in 544 colors covering 0.36 to 3.92 micrometers, and shows features as small as 18 meters (60 feet) across. HiRISE's image was taken in three colors, but its much higher resolution shows features as small as 30 centimeters (1 foot) across. CRISM's sister instrument on the Mars Express spacecraft, OMEGA, discovered that some of the most ancient regions of Mars are rich in clay minerals, formed when water altered the planet's volcanic rocks. From the OMEGA data it was unclear whether the clays formed at the surface during Mars' earliest history of if they formed at depth and were later exposed by impact craters or erosion of the overlying rocks. Clays are an indicator of wet, benign environments possibly suitable for biological processes, making Nili Fossae and comparable regions important targets for both CRISM and HiRISE. In this visualization of the combined data from the two instruments, the CRISM data were used to calculate the strengths of spectral absorption bands due to minerals present in the scene. The two major minerals detected by the instrument are olivine, a mineral characteristic of primitive igneous rocks, and clay. Areas rich in olivine are shown in red, and minerals rich in clay are shown in green. The derived colors were then overlayed on the HiRISE image. The area where the CRISM and HiRISE data overlap is shown at the upper left, and is about 5 kilometers (3 miles) across. The three boxes outlined in blue are enlarged to show how the different minerals in the scene match up with different landforms. In the image at the upper right

  7. Thermostability of montmorillonitic clays

    Directory of Open Access Journals (Sweden)

    Petr Jelínek

    2014-05-01

    Full Text Available Bentonite is one of the most widespread used clays connected with various applications. In the case of foundry technology, bentonite is primarily used as a binder for mold manufacture. Thermal stability of bentonites is a natural property of clay minerals and it depends on the genesis, source and chemical composition of the clay. This property is also closely connected to bentonite structure. According to DTA analysis if only one peak of dehydroxylation is observed (about 600 ºC, the cis- isomerism of bentonite is expected, while two peaks of de-hydroxylation (about 550 and 850 ºC are expected in the trans- one. In this overview, the bentonite structure, the water – bentonite interaction and the swelling behavior of bentonite in connection with the general technological properties of bentonite molding mixture are summarized. Further, various types of methods for determination of bentonite thermostability are discussed, including instrumental analytical methods as well as methods that employ evaluation of various technological properties of bentonite binders and/or bentonite molding mixtures.

  8. Thermostability of montmorillonitic clays

    Institute of Scientific and Technical Information of China (English)

    Petr Jelnek; Stanisaw M.Dobosz; Jaroslav Beo; Katarzyna Major-Gabry

    2014-01-01

    Bentonite is one of the most widespread used clays connected with various applications. In the case of foundry technology, bentonite is primarily used as a binder for mold manufacture. Thermal stability of bentonites is a natural property of clay minerals and it depends on the genesis, source and chemical composition of the clay. This property is also closely connected to bentonite structure. According to DTA analysis if only one peak of dehydroxylation is observed (about 600 ºC), thecis- isomerism of bentonite is expected, while two peaks of de-hydroxylation (about 550 and 850 ºC) are expected in thetrans- one. In this overview, the bentonite structure, the water - bentonite interaction and the sweling behavior of bentonite in connection with the general technological properties of bentonite molding mixture are summarized. Further, various types of methods for determination of bentonite thermostability are discussed, including instrumental analytical methods as wel as methods that employ evaluation of various technological properties of bentonite binders and/or bentonite molding mixtures.

  9. Comparative results of copper flotation from smelter slag and granulated smelter slag

    OpenAIRE

    Milanović, Dragan; Stanujkić, Dragiša; Ignjatović, Miroslav R.

    2013-01-01

    Smelter slag is obtained in the process of metallurgical converting of copper concentrate in the Smelter Plant in Bor, Serbia. Today, the reserves of this material are evaluated at about more of a year, with the average copper content of 0.6-0.9%. Production of copper concentrate by flotation of smelter slag has started in 2001. Flotation concentrate goes to the Copper Smelter once more for production of copper cathodes and the rough flotation tailings go to the flotation tailing dump. Copper...

  10. Evaluation of the slag regime and desulphurization of steel with synthetic slag containing Cr2O3

    OpenAIRE

    Socha, Ladislav; Bažan, Jiří; Morávka, Jan; Styrnal, Petr; Machovčák, Pavel; Opler, Aleš; Trefil, Antonín

    2014-01-01

    The paper focuses on an evaluation of the slag regime and steel desulphurisation in a ladle with the help of synthetic slags based on Al2O3 containing various mass amounts of Cr2O3 varying from 0.3 % to 3.0 %. The aim of the plant experiments was to assess the achieved results when using two types of synthetic slag focusing on the course of desulphurisation, an analysis of the achieved chemical composition of the slag and an evaluation of the influence of oxide Cr2O3 on the increase ...

  11. Byproduct aggregate. Copper slag aggregate, ferronickel slag aggregate; Fukusan kotsuzai. Do suragu kotsuzai, fuero nikkeru suragu kotsuzai

    Energy Technology Data Exchange (ETDEWEB)

    Kajiwara, Toshitaka

    1998-08-10

    Copper slag aggregate and ferronickel slag aggregate has not only usual substitute of sand or crushed sand but many features unlike sand or unlike crushed sand. It has many features unlike sand or crushed sand. It seems that especially, behavior of the particulates minute is features of deserving in addition, the examination in future. Of course, one feature also consists on the merit on the demerit by the use. And, copper slag aggregate, ferronickel slag aggregate have also limited the production place at the output of about 2 million annual production tons. These features are utilized, and in addition, wants to teach and want to receive the wider usage. (NEDO)

  12. A Study of Clay-Epoxy Nanocomposites Consisting of Unmodified Clay and Organo Clay

    Directory of Open Access Journals (Sweden)

    Graham Edward

    2006-04-01

    Full Text Available Clay-epoxy nanocomposites were synthesized from DGEBA resin and montmorillonite clay with an in-situ polymerization. One type of untreated clay and two types of organo clay were used to produce the nanocompsoites. The aims of this study were to examine the nanocomposite structure using different tools and to compare the results between the unmodified clay and modified clays as nanofillers. Although diffractogram in reflection mode did not show any apparent peak of both types of materials, the transmitted XRD (X-Ray Difraction graphs, DSC (Differential Scanning Calorimeter analysis and TEM (Transmission Electron Microscope images revealed that the modified clay-epoxy and unmodified clay-epoxy provides different results. Interestingly, the micrographs showed that some of the modified clay layers possessed non-exfoliated layers in the modified clay-epoxy nanocomposites. Clay aggregates and a hackle pattern were found from E-SEM images for both types of nanocomposite materials. It is shown that different tools should be used to determine the nanocomposite structure.

  13. The Portuguese Lioz, a Monumental Limestone

    Science.gov (United States)

    Silva, Zenaide

    2017-04-01

    Lioz is a microcrystalline limestone which occurs in Portugal and outcrops in the Lisbon area and its neighboring counties Oeiras, Pero Pinheiro, Lameiras. The rock is whitish to light and dark pink and contains 120 million years old rudists fossils. This fossiliferous content imprints a decorative aspect to the rock contributing to its very wide use as construction material and its favorite use in churches and official monuments making it the Royal Stone in Portugal along the XVII and XVIII centuries. Lisbon has the best exposition of Lioz as a fundamental stone in several monuments, the best examples being the Jeronimos Monastery, the Belém Tower, the Cultural Center in Belém and many old churches spread in Lisbon area. Among the latter the Jesuit Church of São Roque is a special example. The fact that the rock stratigraphic sequence allows the different rock colors as white, light and dark pink and a yellow facies variety in a local occurrence (Negrais yellow) makes it a special source for decorative patterns that can be found in a few churches in Lisbon, Évora, Mafra exhibiting "embutidos" technique, of indian origin and inspired on contemporaneous Italian churches. Mafra is the place where a monumental architectural set, composed by three integrated constructions, was built in the XVIII century by king D.João V using Lioz limestone as the main rock material, in all available colors. Along the XVII and XVIII centuries, the rock was transported to some portuguese colonies, mainly as ballast to improve the navigability of the boats, and used at the destinations as construction material for monuments, official buildings and churches. Brazil and especially Salvador, in Bahia, is the best example of that, where Lioz is beautifully exposed in monuments and as true art in many churches where the Portuguese or Italian influences are very strong. All these facts make the Portuguese Lioz Limestone as very representative of the Heritage present in Portugal and its

  14. Restoration and Preservation of Engraved Limestone Blocks Discovered in Abu Mousa Excavation, Suez - Egypt

    Directory of Open Access Journals (Sweden)

    Nabil A. Abd El-Tawab BADER

    2013-03-01

    Full Text Available A lot of engraved limestone blocks were discovered at Awlad Abu Musa (east of Suez, Egypt in 1995/2007 by Supreme Council of Antiquities. The stone blocks were seriously affected by archaeological environments during burial environment in agriculture land. They were covered with thick clay layer with soil particles that disfigured them and hid their inscriptions. Prior to the conservation intervention, the materials were characterized by X-ray diffraction, optical microscopy, scanning electron microscopy with energy-dispersive X-ray spectroscopy, Chemical analyses of ground water and microbiological study. After the material characterization, the conservation and restoration of the stone blocks were carried out including cleaning, consolidation, reduction of salts, Re-jointing, restoration and completion of lost parts. After that the blocks were exhibited in Suez museum.

  15. STEAM INJECTION INTO FRACTURED LIMESTONE AT LORING AIR FORCE BASE

    Science.gov (United States)

    A research project on steam injection for the remediation of spent chlorinated solvents from fractured limestone was recently undertaken at the former Loring AFB in Limestone, ME. Participants in the project include the Maine Department of Environmental Protection, EPA Region I,...

  16. Evaluation of blast furnace slag as basal media for eelgrass bed.

    Science.gov (United States)

    Hizon-Fradejas, Amelia B; Nakano, Yoichi; Nakai, Satoshi; Nishijima, Wataru; Okada, Mitsumasa

    2009-07-30

    Two types of blast furnace slag (BFS), granulated (GS) and air-cooled slag (ACS), were evaluated as basal media for eelgrass bed. Evaluation was done by comparing BFS samples with natural eelgrass sediment (NES) in terms of some physico-chemical characteristics and then, investigating growth of eelgrass both in BFS and NES. In terms of particle size, both BFS samples were within the range acceptable for growing eelgrass. However, compared with NES, low silt-clay content for ACS and lack of organic matter content for both BFS samples were found. Growth experiment showed that eelgrass can grow in both types of BFS, although growth rates in BFS samples shown by leaf elongation were slower than that in NES. The possible reasons for stunted growth in BFS were assumed to be lack of organic matter and release of some possible toxins from BFS. Reduction of sulfide content of BFS samples did not result to enhanced growth; though sulfide release was eliminated, release of Zn was greater than before treatment and concentration of that reached to alarming amounts.

  17. Mathematical Modeling on Open Limestone Channel

    CERN Document Server

    Bandstra, Joel; Wu, Naiyi

    2014-01-01

    Acid mine drainage (AMD) is the outflow of acidic water from metal mines or coal mines. When exposed to air and water, metal sulfides from the deposits of the mines are oxidized and produce acid, metal ions and sulfate, which lower the pH value of the water. An open limestone channel (OLC) is a passive and low cost way to neutralize AMD. The dissolution of calcium into the water increases the pH value of the solution. A differential equation model is numerically solved to predict the variation of concentration of each species in the OLC solution. The diffusion of Calcium due to iron precipitates is modeled by a linear equation. The results give the variation of pH value and the concentration of Calcium.

  18. Face logging in Copenhagen Limestone, Denmark

    DEFF Research Database (Denmark)

    Jakobsen, Lisa; Foged, Niels Nielsen; Erichsen, Lars;

    2015-01-01

    The requirement for excavation support can be assessed from face logging. Face logs can also improve our knowledge of lithological and structural conditions within bedrock and supplement information from boreholes and geophysical logs. During the construction of 8 km metro tunnel and 4 km heating...... tunnel in Copenhagen more than 2.5 km face logs were made in 467 locations at underground stations, shafts, caverns and along bored tunnels. Over 160 geotechnical boreholes, many with geophysical logging were executed prior to construction works. The bedrock consists of Paleogene "Copenhagen limestone......" and face logs show a sub-horizontally layered structure, with alternate extremely weak to extremely strong beds of variable thickness. The rhythmicity is thought to be climatically controlled. Stronger beds represent reduced sedimentation rate related to climatic deterioration while weaker beds result from...

  19. Modeling contaminant plumes in fractured limestone aquifers

    DEFF Research Database (Denmark)

    Mosthaf, Klaus; Brauns, Bentje; Fjordbøge, Annika Sidelmann

    the established approaches of the equivalent porous medium, discrete fracture and dual continuum models. However, these modeling concepts are not well tested for contaminant plume migration in limestone geologies. Our goal was to develop and evaluate approaches for modeling the transport of dissolved contaminant...... in the planning of field tests and to update the conceptual model in an iterative process. Field data includes information on spill history, distribution of the contaminant (multilevel sampling), geology and hydrogeology. To describe the geology and fracture system, data from borehole logs, packer tests, optical...... distribution in the aquifer. Different models were used for the planning and interpretation of the pump and tracer test. The models were evaluated by examining their ability to describe collected field data. The comparison with data showed that the models have substantially different representations...

  20. Microfacies and diagenesis of the reefal limestone, Callovian Tuwaiq Mountain Limestone Formation, central Saudi Arabia

    Science.gov (United States)

    EL-Sorogy, Abdelbaset S.; Almadani, Sattam A.; Al-Dabbagh, Mohammad E.

    2016-03-01

    In order to document the microfacies and diagenesis of the reefal limestone in the uppermost part of the Callovian Tuwaiq Mountain Limestone Formation at Khashm Al-Qaddiyah area, central Saudi Arabia, scleractinian corals and rock samples were collected and thin sections were prepared. Coral framestone, coral floatstone, pelloidal packstone, bioclastic packstone, bioclastic wacke/packstone, algal wackestone and bioclastic foraminiferal wacke/packstone were the recorded microfacies types. Cementation, recrystallization, silicification and dolomitization are the main diagenetic alterations affected the aragonitic skeletons of scleractinian corals. All coral skeletons were recrystallized, while some ones were dolomitized and silicified. Microfacies types, as well as the fossil content of sclearctinian corals, bivalves, gastropods, brachiopods and foraminifera indicated a deposition in environments ranging from shelf lagoon with open circulation in quiet water below wave base to shallow reef flank and organic build up for the uppermost reefal part of the Tuwaiq Formation in the study area.

  1. Field trial of a pulsed limestone diversion well

    Science.gov (United States)

    Sibrell, Philip L.; Denholm, C.; Dunn, Margaret

    2013-01-01

    The use of limestone diversion wells to treat acid mine drainage (AMD) is well-known, but in many cases, acid neutralization is not as complete as would be desired. Reasons for this include channeling of the water through the limestone bed, and the slow reaction rate of the limestone gravel. A new approach to improve the performance of the diversion well was tested in the field at the Jennings Environmental Education Center, near Slippery Rock, PA. In this approach, a finer size distribution of limestone was used so as to allow fluidization of the limestone bed, thus eliminating channeling and increasing particle surface area for faster reaction rates. Also, water flow was regulated through the use of a dosing siphon, so that consistent fluidization of the limestone sand could be achieved. Testing began late in the summer of 2010, and continued through November of 2011. Initial system performance during the 2010 field season was good, with the production of net alkaline water, but hydraulic problems involving air release and limestone sand retention were observed. In the summer of 2011, a finer size of limestone sand was procured for use in the system. This material fluidized more readily, but acid neutralization tapered off after several days. Subsequent observations indicated that the hydraulics of the system was compromised by the formation of iron oxides in the pipe leading to the limestone bed, which affected water distribution and flow through the bed. Although results from the field trial were mixed, it is believed that without the formation of iron oxides and plugging of the pipe, better acid neutralization and treatment would have occurred. Further tests are being considered using a different hydraulic configuration for the limestone sand fluidized bed.

  2. China Customs Removed the Import Tax on Titanium Slag

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>The long waited solution to the problem relating to the import of titanium slag has finally resolved. According to China Customs report, the import of titanium slag no longer requires tax payment as from January 1, 2007. This decision will help with the healthy development of China’s titanium industry and increase China’s competitiveness in the international marketplace.

  3. Sulfide capacity of high alumina blast furnace slags

    Science.gov (United States)

    Shankar, Amitabh; Görnerup, Märten; Seetharaman, S.; Lahiri, A. K.

    2006-12-01

    Sulfide capacities of high alumina blast furnace slags were experimentally determined using the gas-slag equilibration technique. Two different slag systems were considered for the current study, namely, CaO-SiO2-MgO-Al2O3 quaternary and CaO-SiO2-MgO-Al2O3-TiO2 quinary system. The liquid slag was equilibrated with the Ar-CO-CO2-SO2 gas mixture. Experiments were conducted in the temperature range of 1773 to 1873 K. The effects of temperature, basicity, and the MgO and TiO2 contents of slags on sulfide capacity were studied. As expected, sulfide capacity was found to increase with the increase in temperature and basicity. At the higher experimental temperature, titania decreases the sulfide capacity of slag. However, at the lower temperature, there was no significant effect of titania on the sulfide capacity of slag. Sulfide capacity increases with the increase in MgO content of slag if the MgO content is more than 5 pct.

  4. Crystallization of Synthetic Blast Furnace Slags Pertaining to Heat Recovery

    Science.gov (United States)

    Esfahani, Shaghayegh

    Heat recovery from blast furnace slags is often contradicted by another requirement, to generate amorphous slag for its use in cement production. As both the rate and extent of heat recovery and slag structure are determined by its cooling rate, a relation between the crystallization kinetics and the cooling conditions is highly desired. In this study, CaO-SiO2-Al2O3-MgO (CSAM) slags with different basicities were studied by Single Hot Thermocouple Technique (SHTT) during isothermal treatment and non-isothermal cooling. Their time-temperature-transformation (TTT) and continuous-cooling-transformation (CCT) diagrams were plotted and compared with each other. Furthermore, kinetic parameters such as the Avrami exponent (n), rate coefficient (K) and effective activation energy of crystallization (EA) were found by analysis of data obtained from in-situ observation of glassy to crystalline transformation and image analysis. Also, the dependence of nucleation and growth rates of crystalline phases were quantified as a function of time, temperature, and slag basicity. Together with the observations of crystallization front, they facilitated establishing the dominant mechanisms of crystallization. In addition to the experimental work, a mathematical model was developed and validated that predicts the amount of crystallization during cooling. A second mathematical model that calculates temperature history of slag during its cooling was coupled with the above model, to allow studying the effect of parameters such as the slag/air ratio and granule size on the heat recovery and glass content of slag.

  5. Refractory Degradation by Slag Attack in Coal Gasification

    Science.gov (United States)

    2009-02-01

    REFRACTORY DEGRADATION BY SLAG ATTACK IN COAL GASIFICATION Jinichiro Nakano 1,2 , Sridhar Seetharaman 1,2 , James Bennett 3 , Kyei-Sing...00-2009 4. TITLE AND SUBTITLE Refractory Degradation by Slag Attack in Coal Gasification 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM

  6. Treatment of LF slag to prevent powdering during cooling

    Directory of Open Access Journals (Sweden)

    Ghorai S.

    2017-01-01

    Full Text Available The polymorphic transformation of the monoclinic β-polymorph to the orthorhombic γ-polymorph of di-calcium silicate at around 500°C during cooling results in disintegration of slag. The slag generated, during the production of thermo mechanically treated steel in ladle furnace at M/s Tata Steel Limited, Jamshedpur, India, behaves in similar manner. An attempt has been made to prevent the crumbling of ladle furnace slag. The experiments were conducted in 10 kg air induction furnace. Various types of silica source were used to prevent the disintegration of ladle furnace slag by reducing the basicity and optimizing the additives amount. Apart from silica sources, other additives like borax and barium carbonate were also used to stabilize the β phase. Present investigation reveals that disintegration of ladle furnace slag can be prevented either by addition of 0.2% boarx or 2% barium carbonate. Dust formation can also be prevented by decreasing the ladle furnace slag basicity to about 1.7. Toxicity Characteristic Leaching Procedure test, of the borax and barium carbonate treated slag samples, indicates that barium carbonate treated slag cannot be used for the dusting prevention as it contains high level of barium.

  7. Study of Reaction Between Slag and Carbonaceous Materials

    Science.gov (United States)

    Maroufi, Samane; Mayyas, Mohannad; Mansuri, Irshad; O'Kane, Paul; Skidmore, Catherine; Jin, Zheshi; Fontana, Andrea; Sahajwalla, Veena

    2017-10-01

    The chemical interaction of a typical slag of EAF with three different carbon sources, coke, rubber-derived carbon (RDC), coke-RDC blend, was studied in atmospheric pressure at 1823 K (1550 °C). Using an IR-gas analyzer, off-gases evolved from the sample were monitored. While the coke-RDC blend exhibited the best reducing performance in reaction with molten slag, the RDC sample showed poor interaction with the molten slag. The gasification of the coke, RDC, and coke-RDC blend was also carried out under oxidizing conditions using a gas mixture of CO2 (4 wt pct) and Ar (96 wt pct) and it was shown that the RDC sample had the highest rate of gasification step C0 \\mathop{\\longrightarrow}\\limits{{k3 }}{CO} + nCf (11.6 site/g s (×6.023 × 1023/2.24 × 104)). This may be attributed to its disordered structure confirmed by Raman spectra and its nano-particle morphology observed by FE-SEM. The high reactivity of RDC with CO2 provided evidence that the Boudouard reaction was fast during the interaction with molten slag. However, low reduction rate of iron oxide from slag with RDC can be attributed to the initial weak contact between RDC and molten slag implying that the contact between carbonaceous matter and slag plays significant roles in the reduction of iron oxide from slag.

  8. Micronutrient availability from steel slag amendment in pine bark substrates

    Science.gov (United States)

    Steel slag is a byproduct of the steel industry that can be used as a liming agent, but also has a high mineral nutrient content. While micronutrients are present in steel slag, it is not known if the mineral form of the micronutrients would render them available for plant uptake. The objective of...

  9. Phase analytical studies of industrial copper smelting slags. Part I: Silicate slags

    Science.gov (United States)

    Rüffler, R.; Dávalos, J.

    1998-12-01

    The pyrometallurgical extraction of copper from sulfide ore concentrates is determined by the behaviour of the associated iron during smelting. Hence, 57Fe Mössbauer spectroscopy is an attractive tool for studying the phases in silicate slags from German and Chilean smelting plants. Other methods used were ore microscopy, electron microprobe analysis, and X-ray powder diffraction.

  10. Effects of Elazig region waste brick and limestone powder on engineering properties of self-compacting mortar

    Directory of Open Access Journals (Sweden)

    Merve Açıkgenç

    2013-06-01

    Full Text Available The aim of this study is to investigate the effects of using mineral additives on Self compacting Mortar's (SCM strength and viscosity properties. As Self-compacting concrete (SCC contains less coarse aggregate than conventional concrete, mortar forms the basis of the design of SCC. Therefore, this study was found to be appropriate to use mortar. In addition, the properties of SCC such as required strength, durability and workability makes a good production of concrete inevitable. While Providing this properties, it has been presented in many studies that mineral additive (silica fume, fly ash, limestone powder, blast furnace slag etc. and certain amount of powder material requirement is essential especially in terms of workability and consistency of SCC. Furthermore, it was aimed to prevent environmental health threats by wastes released disorderly and to add new powder material to be used in SCC and finally to reduce the cost of both transport and cement by using limestone and waste brick powder. For this purpose, 23 types of mortars, in which cement was partially replaced of limestone and waste brick powder, were produced. The mini slump flow and V-funnel tests were used to assess the workability and the self compactivity properties of the fresh mortars, and the viscosity of mortars were also measured. The hardened properties of SCM specimens including the compressive strength and tensile strength in bending were investigated and all tests were performed for 3, 7, 28 and 91 days. Moreover, capillary water absorption test were performed and, total water absorption and porosity rates of all specimens were measured.

  11. Slag-Resistance of MgAlON Spinel

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The slag-resistance and microstructural changes after the slag tests of MgAlON spinel containing different amount of nitrogen were studied by means of crucible slag-resistant experiment, SEM and EDS in the work. The results show that the slag-resistance of MgAlON is dependent on the nitrogen content, and the optimum amount is 2.88%. The structure is not changed although the grains have been permeated by some silicon, calcium and iron. A glass phase which contained nitrogen formed in the metamorphic layer. The glass can improve the ability of the slag-resistance of MgAlON because of its higher viscosity.

  12. Chemical and mineralogical characterizations of a copper converter slag

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A copper converter slag was examined chemically and mineralogically to determine its existing phases, in particular those containing Co and Cu. The slag consists predominantly of fayalite and magnetite, together with some glass,chalcocite, and metallic copper. Copper is entrapped in the slag mostly as chalcocite and metallic copper, as well as trace copper oxide. There was no indication of any independent Co mineral in the slag, but Co was found to be enriched in fayalite and megnetite as solid solution, although Co was detected in all the phases of the slag by SEM-EDX (scanning electron microscopy equipped with model EDAX-9100 energy dispersive spectrometer) and WDS (model WDX-2A X-ray wave-length dispersive spectrometer).

  13. Characterization and Recovery of Valuables from Waste Copper Smelting Slag

    Science.gov (United States)

    Prince, Sarfo; Young, Jamie; Ma, Guojun; Young, Courtney

    Silicate slags produced from smelting copper concentrates contains valuables such as Cu and Fe as well as heavy metals such as Pb and As which are considered hazardous. In this paper, various slags were characterized with several techniques: SEM-MLA, XRD, TG-DTA and ICP-MS. A recovery process was developed to separate the valuables from the silicates thereby producing value-added products and simultaneously reducing environmental concerns. Results show that the major phases in air-cooled slag are fayalite and magnetite whereas the water-cooled slag is amorphous. Thermodynamic calculations and carbothermal reduction experiments indicate that most of Cu and Fe can be recovered from both types using minor amounts of lime and alumina and treating at 1350°C (1623K) or higher for 30 min. The secondary slag can be recycled to the glass and/or ceramic industries.

  14. Roles of Mineralogical Phases in Aqueous Carbonation of Steelmaking Slag

    Directory of Open Access Journals (Sweden)

    Huining Zhang

    2016-05-01

    Full Text Available Mineralogical phases of steelmaking slags have significant influences on the carbonation of the slags. In this paper, the effects of temperature and reaction time on the conversion of calcium-related phases and the carbonation degree of a slag sample were studied. The experimental conditions were a liquid-to-solid ratio of 20 mL/g, a carbon dioxide flow rate of 1 L/min and a slag particle size of 38–75 μm. The results show that the optimum carbonation temperature and reaction time are 60 °C and 90 min, respectively, and calcite phase content is about 26.78% while the conversion rates of Ca3Al2O6, CaSiO3, Ca2SiO4 and free CaO are about 40%, 42.46%, 51% and 100%, respectively, and the carbon dioxide sequestration efficiency is about 170 g/kg slag.

  15. Modeling and control of copper loss in smelting slag

    Science.gov (United States)

    Tan, Pengfu

    2011-12-01

    A series of technical improvements have been implemented to address the issue of high copper losses in rotary holding furnace (RHF) slag, which were experienced at the Xstrata Copper Smelter at Mount Isa in 2007 and 2008. The copper losses in smelting slag in the RHF were more than 3% in 2006 and 2007. Thermodynamic models and viscosity models have been applied in the operation of Xstrata Copper Smelter in Australia. The theory of RHF key performance indicators has also been developed to reduce the copper losses in RHF slag. The RHF KPIs Theory has been applied in Mount Isa Copper Smelter. The copper losses in RHF slag dropped from 3.1% in 2007 to 0.76% in April 2009. The average copper loss in RHF slag in 2009 and 2010 was about 0.9%.

  16. Physical Properties of Crushed Air-cooled Blast Furnace Slag and Numerical Representation of Its Morphology Characteristics

    Institute of Scientific and Technical Information of China (English)

    WANG Aiguo; DENG Min; SUN Daosheng; LI Bing; TANG Mingshu

    2012-01-01

    Physical properties and geometrical morphologies of crushed air-cooled blast furnace slag (SCR) and crushed limestone (LCR) were comparatively investigated.The shape,angularity,surface texture and internal pore structure of aggregate particles for different size and gradation were numerically represented by sphericity (ψ) and shape index (SI),angularity number (AN),index of aggregate particle shape and texture (IAPST),porosity and pore size,respectively.The results show that SCR is a porous and rough aggregate.Apparent density,void,water absorption and smashing index of SCR are obviously higher than those of LCR with the same gradation,respectively.However,bulk density of SCR is lower than that of LCR with the same gradation.SI,AN,IAPST and porosity of SCR are obviously higher than those of LCR with the same gradation,respectively.The smaller particle size of SCR,the larger of its AN,IAPST and porosity.

  17. 80 FR 65469 - NESHAP for Brick and Structural Clay Products Manufacturing; and NESHAP for Clay Ceramics...

    Science.gov (United States)

    2015-10-26

    ... Clay Products Manufacturing; and NESHAP for Clay Ceramics Manufacturing; Final Rule #0;#0;Federal...; and NESHAP for Clay Ceramics Manufacturing AGENCY: Environmental Protection Agency (EPA). ACTION... NESHAP for Clay Ceramics Manufacturing. All major sources in these categories must meet...

  18. Catalysts derived from waste slag for transesterification

    Institute of Scientific and Technical Information of China (English)

    Xiaowei Zhang; Wei Huang

    2011-01-01

    MgO-CaO/SiO2 solid catalysts derived from waste slag (WS) of metal magnesium plant were prepared.The catalytic performances were evaluated in the transesterification of rapeseed oil with methanol to biodiesel in a 500 mL three-necked reactor under atmospheric pressure.The basic strengh of the catalyst reached 22.0 measured by indicators accroding to Hammett scale.The results show that the MgO-CaO/SiO2 is an excellent catalyst for transesterification, and the conversion of rapeseed oil reach 98% under the optimum condition.

  19. United Arab Emirates limestones: impact of petrography on thermal behavior

    Science.gov (United States)

    Alaabed, Sulaiman; Soltan, Abdel Monem; Abdelghany, Osman; Amin, Bahaa Eldin Mahmoud; El Tokhi, Mohamed; Khaleel, Abbas; Musalim, Abdullah

    2014-12-01

    The thermal behavior of selected limestones from representative localities of the United Arab Emirates is investigated for their suitability for soft-burnt lime production. The limestone samples were collected from the Ghalilah, Musandam, Shauiba, Muthaymimah, Dammam and Asmari formations. The samples were characterized for petrography, mineral and chemical composition, together with physico-mechanical characteristics. Investigative methods included transmitted light microscopy (TLM), cathodoluminescence (CLM) and scanning electron microscopy (SEM), as well as X-ray micro-tomography (μ-CT), XRD, XRF and Archimedes method. The limestone samples were fired in an electrical muffle furnace for 0.25, 0.5, 1 and 2 hours at 800, 900, 1,000 and 1,100 °C. After firing the lime grains were tested to determine their hydration rate and microfabric. The Ghalilah and Musandam limes show the lowest and highest maximum hydration rates, respectively, due mainly to the impure nature of the former, and the smaller lime crystallites and dominance of post-calcination micro-cracks of the latter. The Dammam and Asmari limes preserve a "ghost" microfabric of the original limestone. Higher allochem contents impose lower activation energy requirements for calcination, which implies earlier calcination of the allochems. The Musandam, Shauiba and Muthaymimah limestones may be useful for the production of reactive soft-burnt lime under the applied firing conditions, however, the Dammam and Asmari limestones need more advanced calcination conditions than the applied ones. The Ghalilah limestone was found to be unsuitable for the production of lime.

  20. Clay resources in the Netherlands

    NARCIS (Netherlands)

    Meulen, M.J. van der; Maljers, D.; Gessel, S.F. van; Gruijters, S.H.L.L.

    2007-01-01

    Clay is a common lithology in the Dutch shallow subsurface. It is used in earth constructions such as dikes, and as raw material for the fabricationof bricks, roof tiles etc. We present a new national assessment of Dutch clay resources, as part of a project that provides mineral-occurrenceinformatio

  1. Clay resources in the Netherlands

    NARCIS (Netherlands)

    Meulen, M.J. van der; Maljers, D.; Gessel, S.F. van; Gruijters, S.H.L.L.

    2007-01-01

    Clay is a common lithology in the Dutch shallow subsurface. It is used in earth constructions such as dikes, and as raw material for the fabrication of bricks, roof tiles etc. We present a new national assessment of Dutch clay resources, as part of a project that provides mineral-occurrence informat

  2. Fluoride retention by kaolin clay

    DEFF Research Database (Denmark)

    Kau, P. M. H.; Smith, D. W.; Binning, Philip John

    1997-01-01

    To evaluate the potential effectiveness of kaolin clay liners in storage of fluoride contaminated waste, an experimental study of the sorption and desorption behaviour of fluoride in kaolin clay was conducted. The degree of fluoride sorption by kaolin was found to depend on solution p...

  3. Viscous property of dried clay

    Institute of Scientific and Technical Information of China (English)

    XU Li-sheng; LI Jian-zhong

    2006-01-01

    One dimensional and triaxial compression tests of air-dried and oven-dried Fujinomori clay and Pisa clay were carried out. Water content is less than 4.5 % and 1.0% for air-dried and oven-dried clay specimens, respectively. In all tests, axial strain rate was changed stepwise many times and drained creep tests were performed several times during monotonic loading at a constant strain rate. Global unloading (and also reloading in some tests) was applied during which creep loading tests were performed several times. Cyclic loading with small stress amplitude and several cycles was also performed to calculate the modulus of elasticity of the clay in tests. Local displacement transducer was used in triaxial compression test to increase measuring accuracy of axial strain. The results show that air-dried and oven-dried clay have noticeable viscous properties; during global unloading, creep deformation changes from positive to negative, i.e. there exist neutral points (zero creep deformation or no creep deformation point) in global unloading part of strain-stress curve; viscous property of Fujinomori clay decreases when water content decreases, i.e. viscous property of air-dried Fujinomori clay is more significant than that of oven-dried Fujinomori clay.

  4. Limestone quarry becomes a wind farm

    Energy Technology Data Exchange (ETDEWEB)

    Wizelius, T. [Vindform (Sweden)

    2000-06-01

    A former limestone quarry on the coast at Smoejen in eastern Gotland, Sweden, has been converted into a wind farm delivering 10 MW of electricity to the grid. Two Enercon turbines were installed at the site in 1995 and a further eight Vestas turbines in 1999; the latter cost 80 million SEK (US$9.6 million), including 11 million SEK for grid connection. The wind farm's expansion in 1999 involved construction of new access roads and extensive foundations on which to mount the four 660 kW and four 1.65 MW turbines. Grid connection is a significant issue as the wind farm is expected to generate some 27 GWh/year. The eight new turbines have internal transformers connected underground to interlocking plants. One of the reasons for using different sizes of turbines is to alleviate environmental concerns; the larger turbines are located within the quarry, thus reducing the number of trees felled and improving the wind farm's visual appearance.

  5. Residual CO2 trapping in Indiana limestone.

    Science.gov (United States)

    El-Maghraby, Rehab M; Blunt, Martin J

    2013-01-01

    We performed core flooding experiments on Indiana limestone using the porous plate method to measure the amount of trapped CO(2) at a temperature of 50 °C and two pressures: 4.2 and 9 MPa. Brine was mixed with CO(2) for equilibration, then the mixture was circulated through a sacrificial core. Porosity and permeability tests conducted before and after 884 h of continuous core flooding confirmed negligible dissolution. A trapping curve for supercritical (sc)CO(2) in Indiana showing the relationship between the initial and residual CO(2) saturations was measured and compared with that of gaseous CO(2). The results were also compared with scCO(2) trapping in Berea sandstone at the same conditions. A scCO(2) residual trapping end point of 23.7% was observed, indicating slightly less trapping of scCO(2) in Indiana carbonates than in Berea sandstone. There is less trapping for gaseous CO(2) (end point of 18.8%). The system appears to be more water-wet under scCO(2) conditions, which is different from the trend observed in Berea; we hypothesize that this is due to the greater concentration of Ca(2+) in brine at higher pressure. Our work indicates that capillary trapping could contribute to the immobilization of CO(2) in carbonate aquifers.

  6. Clay minerals in pollution control

    Energy Technology Data Exchange (ETDEWEB)

    Tateo, F. [Consiglio Nazionale delle Ricerche, Istituto di Ricerca sulle Argille, Tito Scalo, PZ (Italy)

    2000-07-01

    Clay minerals are fundamental constituents of life, not only as possible actors in the development of life on the Earth (Cairns-Smith and Hartman, 1986), but mainly because they are essential constituents of soils, the interface between the solid planet and the continental biosphere. Many, many authors have devoted themselves to the study of clays and clay minerals since the publication of the early modern studies by Grim (1953, 1962) and Millot (1964). In those years two very important associations were established in Europe (Association Internationale pour l'Etude des Argiles, AIPEA) and in the USA (Clay Mineral Society, CMS). The importance of these societies is to put together people that work in very different fields (agronomy, geology, geochemistry, industry, etc.), but with a common language (clays), very useful in scientific work. Currently excellent texts are being published, but introductory notes are also available on the web (Schroeder, 1998).

  7. Mineral resource of the Month: Clay

    Science.gov (United States)

    Virta, Robert L.

    2010-01-01

    Clays were one of the first mineral commodities used by people. Clay pottery has been found in archeological sites that are 12,000 years old, and clay figurines have been found in sites that are even older.

  8. On the Dissolution Behavior of Sulfur in Ternary Silicate Slags

    Science.gov (United States)

    Kang, Youn-Bae; Park, Joo Hyun

    2011-12-01

    Sulfur dissolution behavior, in terms of sulfide capacity ( C S), in ternary silicate slags (molten oxide slags composed of MO - NO - SiO2, where M and N are Ca, Mn, Fe, and Mg), is discussed based on available experimental data. Composition dependence of the sulfur dissolution, at least in the dilute region of sulfur, may be explained by taking into account the cation-anion first-nearest-neighbor (FNN) interaction (stability of sulfide) and the cation-cation second-nearest-neighbor (SNN) interaction over O anion (oxygen proportions in silicate slags). When the Gibbs energy of a reciprocal reaction MO + NS = MS + NO is positive, the sulfide capacity of slags with virtually no SiO2 or low SiO2 concentration decreases as the concentration of MO increases. However, in some slags, as SiO2 concentration increases, replacing NO by MO at a constant SiO2 concentration may increase sulfide capacity when the basicity of NO is less than that of MO. This phenomenon is observed as rotation of iso- C S lines in ternary silicate slags, and it is explained by simultaneous consideration of the stability of sulfide and oxygen proportions in the silicate slags. It is suggested that a solution model for the prediction of sulfide capacity should be based on the actual dissolution mechanism of sulfur rather than on the simple empirical correlation.

  9. Characterization and recovery of copper values from discarded slag.

    Science.gov (United States)

    Das, Bisweswar; Mishra, Barada Kanta; Angadi, Shivakumar; Pradhan, Siddharth Kumar; Prakash, Sandur; Mohanty, Jayakrushna

    2010-06-01

    In any copper smelter large quantities of copper slag are discarded as waste material causing space and environmental problems. This discarded slag contains important amounts of metallic values such as copper and iron. The recovery of copper values from an Indian smelter slag that contains 1.53% Cu, 39.8% Fe and 34.65% SiO(2) was the focus of the present study. A complete investigation of the different phases present in the slag has been carried out by means of optical microscopy, Raman spectroscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD) techniques. It is observed that iron and silica are mostly associated with the fayalite phase whereas copper is present in both oxide and sulfide phases. These oxide and sulfide phases of copper are mostly present within the slag phase and to some extent the slag is also embedded inside the oxide and sulfide phases. The recovery of copper values from the discarded slag has been explored by applying a flotation technique using conventional sodium isopropyl xanthate (SIX) as the collector. The effects of flotation parameters such as pH and collector concentration are investigated. Under optimum flotation conditions, it is possible to achieve 21% Cu with more than 80% recovery.

  10. Vanadium bioavailability in soils amended with blast furnace slag

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, Maja A., E-mail: maja.larsson@slu.se [Department of Soil and Environment, Swedish University of Agricultural Sciences, P.O. Box 7014, 750 07 Uppsala (Sweden); Baken, Stijn, E-mail: stijn.baken@ees.kuleuven.be [Department of Earth and Environmental Sciences, Leuven University, Kasteelpark Arenberg 20 bus 2459, 3001 Leuven (Belgium); Smolders, Erik, E-mail: erik.smolders@ees.kuleuven.be [Department of Earth and Environmental Sciences, Leuven University, Kasteelpark Arenberg 20 bus 2459, 3001 Leuven (Belgium); Cubadda, Francesco, E-mail: francesco.cubadda@iss.it [Department of Food Safety and Veterinary Public Health, Istituto Superiore di Sanità, Viale Regina Elena 299, Rome 00161 (Italy); Gustafsson, Jon Petter, E-mail: jon-petter.gustafsson@slu.se [Department of Soil and Environment, Swedish University of Agricultural Sciences, P.O. Box 7014, 750 07 Uppsala (Sweden); Division of Land and Water Resources Engineering, KTH Royal Institute of Technology, Brinellvägen 28, 100 44 Stockholm (Sweden)

    2015-10-15

    Blast furnace (BF) slags are commonly applied as soil amendments and in road fill material. In Sweden they are also naturally high in vanadium. The aim of this study was to assess the vanadium bioavailability in BF slags when applied to soil. Two soils were amended with up to 29% BF slag (containing 800 mg V kg{sup −1}) and equilibrated outdoors for 10 months before conducting a barley shoot growth assay. Additional soil samples were spiked with dissolved vanadate(V) for which assays were conducted two weeks (freshly spiked) and 10 months (aged) after spiking. The BF slag vanadium was dominated by vanadium(III) as shown by V K-edge XANES spectroscopy. In contrast, results obtained by HPLC-ICP-MS showed that vanadium(V), the most toxic vanadium species, was predominant in the soil solution. Barley shoot growth was not affected by the BF slag additions. This was likely due to limited dissolution of vanadium from the BF slag, preventing an increase of dissolved vanadium above toxic thresholds. The difference in vanadium bioavailability among treatments was explained by the vanadium concentration in the soil solution. It was concluded that the vanadium in BF slag is sparingly available. These findings should be of importance in environmental risk assessment.

  11. Characterization of chilean copper slag smelting nineteenth century

    Directory of Open Access Journals (Sweden)

    Amin Nazer

    2016-12-01

    Full Text Available The aim of this work is to characterize four copper smelters slag nineteenth century, from abandoned landfills in Atacama Region - Chile, using the techniques of X-ray fluorescence (XRF, X-ray diffraction (XRD, scanning electron microscopy (SEM, particle analysis by laser diffraction (ADL, Fourier Transform Infrared Spectroscopy (FTIR and thermogravimetric analysis (TGA. Copper slags studied were chemically classified as acidic slags, this slags presented higher SiO2 content (38–49% than Fe2O3 (18–37% and a significant amount of CaO (8–26% and Al2O3 (8.5%. Mineralogy and structure was varied, presenting one of them an amorphous structure and the remaining three, a crystalline structure with partially amorphous character. The majority mineral phases presented in the copper slag were diopside, fayalite, magnetite, cristobalite and clinoferrosilita. Calcium levels indicate that the slags could have cementitious properties for use as a binder in construction materials. Moreover, the significant amount of slag available and CuO content (0.6–1.2% show that may be of interest as raw material for metal recovery.

  12. Vanadium bioavailability in soils amended with blast furnace slag.

    Science.gov (United States)

    Larsson, Maja A; Baken, Stijn; Smolders, Erik; Cubadda, Francesco; Gustafsson, Jon Petter

    2015-10-15

    Blast furnace (BF) slags are commonly applied as soil amendments and in road fill material. In Sweden they are also naturally high in vanadium. The aim of this study was to assess the vanadium bioavailability in BF slags when applied to soil. Two soils were amended with up to 29% BF slag (containing 800 mg V kg(-1)) and equilibrated outdoors for 10 months before conducting a barley shoot growth assay. Additional soil samples were spiked with dissolved vanadate(V) for which assays were conducted two weeks (freshly spiked) and 10 months (aged) after spiking. The BF slag vanadium was dominated by vanadium(III) as shown by V K-edge XANES spectroscopy. In contrast, results obtained by HPLC-ICP-MS showed that vanadium(V), the most toxic vanadium species, was predominant in the soil solution. Barley shoot growth was not affected by the BF slag additions. This was likely due to limited dissolution of vanadium from the BF slag, preventing an increase of dissolved vanadium above toxic thresholds. The difference in vanadium bioavailability among treatments was explained by the vanadium concentration in the soil solution. It was concluded that the vanadium in BF slag is sparingly available. These findings should be of importance in environmental risk assessment.

  13. Utilizing steel slag in environmental application - An overview

    Science.gov (United States)

    Lim, J. W.; Chew, L. H.; Choong, T. S. Y.; Tezara, C.; Yazdi, M. H.

    2016-06-01

    Steel slags are generated as waste material or byproduct every day from steel making industries.The potential environmental issues which are related with the slag dump or reprocessing for metal recovery are generally being focused in the research. However the chemistry and mineralogy of slag depends on metallurgical process which is able to determine whether the steel slag can be the reusable products or not. Nowadays, steel slag are well characterized by using several methods, such as X-ray Diffraction, ICP-OES, leaching test and many more. About the industrial application, it is mainly reused as aggregate for road construction, as armour stones for hydraulic engineering constructions and as fertilizers for agricultural purposes. To ensure the quality of steel slag for the end usage, several test methods are developed for evaluating the technical properties of steel slag, especially volume stability and environmental behaviour. In order to determine its environmental behaviour, leaching tests have been developed. The focus of this paper however is on those applications that directly affect environmental issues including remediation, and mitigation of activities that negatively impact the environment.

  14. UTILIZATION OF LIGHTWEIGHT MATERIALS MADE FROM COAL GASIFICATION SLAGS

    Energy Technology Data Exchange (ETDEWEB)

    Vas Choudhry; Stephen Kwan; Steven R. Hadley

    2001-07-01

    The objective of the project entitled ''Utilization of Lightweight Materials Made from Coal Gasification Slags'' was to demonstrate the technical and economic viability of manufacturing low-unit-weight products from coal gasification slags which can be used as substitutes for conventional lightweight and ultra-lightweight aggregates. In Phase I, the technology developed by Praxis to produce lightweight aggregates from slag (termed SLA) was applied to produce a large batch (10 tons) of expanded slag using pilot direct-fired rotary kilns and a fluidized bed calciner. The expanded products were characterized using basic characterization and application-oriented tests. Phase II involved the demonstration and evaluation of the use of expanded slag aggregates to produce a number of end-use applications including lightweight roof tiles, lightweight precast products (e.g., masonry blocks), structural concrete, insulating concrete, loose fill insulation, and as a substitute for expanded perlite and vermiculite in horticultural applications. Prototypes of these end-use applications were made and tested with the assistance of commercial manufacturers. Finally, the economics of expanded slag production was determined and compared with the alternative of slag disposal. Production of value-added products from SLA has a significant potential to enhance the overall gasification process economics, especially when the avoided costs of disposal are considered.

  15. Iridium contents in the Late Cretaceous-Early Tertiary clays in relation to the K/T boundary, North Jordan

    Science.gov (United States)

    Abboud, Iyad Ahmed

    2016-06-01

    The mineralogy, lithology, and geochemistry of five discrete laminations across the K/T boundary of clayey shale at the Yarmouk River area, Jordan, were examined. There were no marked changes in the mineralogy of the clayey shale within the K/T boundary. This outcrop consists of more than 100 m of Maastrichtian oil shale overlying about 20 m limestone. Marly limestone included many clay laminations from organic and volcanic origins, which are considered an evidence of the K/T boundary through detected iridium anomalies. Any of these particular lamellae range from 2 mm to 5 mm in thickness. Smectite was the predominant clay mineral in smectitic shale laminations. It was located at eight meters above the K/T boundary and includes some anomalous concentrations of iridium and traces of other elements. The analysis of geochemical platinum group at the K/T boundary clays showed anomalous enrichments of iridium, compared with other carbonate rocks as a result of weathering processes of oil shale, or through concentration from weathering of basalt flows, but not pointing to an impact process. The clays in late Maastrichtian have Ir-Sc prevailed anomalies and synchronize with increasing of terrigenous and volcanogenic traced elements. Kaolin, smectite, and volkonskoite were the dominant clay minerals at the K/T boundary with high concentrations of iridium. The concentration levels of iridium in some laminations of the Yarmouk sediments ranged between 1.6 and 7.8 ppb.

  16. Viscosity and Plasticity of Latvian Illite Clays

    OpenAIRE

    2012-01-01

    Due to viscosity and plasticity, clays and clay minerals are used in civil engineering, pottery and also in cosmetics and medicine as thickening agents and emulsion and suspension stabilizers. The rheological properties of clay suspensions are complex. Mostly it is an interaction between mineral composition, clay particle size and pH value and also depends on clay minerals. Clay-water suspension is non-Newtonian fluid showing thixotropic and pseudoplastic properties. Results showed that plast...

  17. Lutetian limestones in the Paris region: Petrographic and compositional examination

    Energy Technology Data Exchange (ETDEWEB)

    Blanc, A. [Lab. de Recherche des Monuments Historiques, Champs-sur-Marne (France); Holmes, L.L.; Harbottle, G. [Brookhaven National Lab., Upton, NY (United States). Chemistry Dept.

    1998-12-31

    Stone for building and decorating monuments in the Paris Basin from antiquity to the present came from numerous quarries in the Lutetian limestone formations of the region. To identify specific stone sources used for masonry and sculptures in these monuments, a team of geologists and archaeologists have investigated 300 quarries and collected 2,300 limestone samples for study in a collaborative effort by geologists and chemists. Petrographic and paleontologic examinations of thin sections enable geologists to distinguish the Tertiary Lutetian limestones from similar stone in Jurassic and Cretaceous strata. The methods of the geologist have been supplemented by those of the chemistry whose compositional studies by neutron activation analysis can differentiate among the fine-grained upper Lutetian limestones extracted from specific ancient quarries.

  18. LUTETIAN LIMESTONES IN THE PARIS REGION: PETROGRAPHIC AND COMPOSITIONAL EXAMINATION

    Energy Technology Data Exchange (ETDEWEB)

    BLANC,A.; HOLMES,L.L.; HARBOTTLE,G.

    1998-06-11

    Stone for building and decorating monuments in the Paris Basin from antiquity to the present came from numerous quarries in the Lutetian limestone formations of the region. To identify specific-stone sources used for masonry and sculptures in these monuments, a team of geologists and archaeologists has investigated 300 quarries and collected 2,300 limestone samples for study in a collaborative effort by geologists and chemists. Petrographic and paleontologic examinations of thin sections enable geologists to distinguish the Tertiary Lutetian limestones from similar stone in Jurassic and Cretaceous strata. The methods of the geologist have been supplemented by those of the chemist whose compositional studies by neutron activation analysis can differentiate among the fine-grained upper Lutetian limestones extracted from specific ancient quarries.

  19. Parcels and Land Ownership, Published in 2011, Limestone County Government.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Parcels and Land Ownership dataset as of 2011. The extent of these data is generally Limestone County, AL. This metadata was auto-generated through the Ramona...

  20. Egyptian limestone for gamma dosimetry: an electron paramagnetic resonance study

    Science.gov (United States)

    Salama, E.

    2014-04-01

    The electron paramagnetic resonance (EPR) properties of limestone from a certain Egyptian site were investigated in order to propose an efficient and low-cost gamma dosimeter. Radiation-induced free radicals were of one type which was produced in the limestone samples at g=2.0066 after exposure to gamma radiation (60Co). EPR spectrum was recorded and analyzed. The microwave power saturation curve and the effect of changing modulation amplitude on peak-to- peak signal height were investigated. The response of limestone to different radiation doses (0.5-20 kGy) was studied. Except for the decrease in signal intensities during the first five hours following irradiation, over the period of two months fair stabilities of signal intensities were noticed. From the current results, it is possible to conclude that natural limestone may be a suitable material for radiation dosimetry in the range of irradiation processing.

  1. Kinetic Study of Calcination of Jakura Limestone Using Power Rate ...

    African Journals Online (AJOL)

    National Research Institute for Chemical Technology, P.M. B 1052, Zaria, Kaduna State, Nigeria. [*Author ... calcination of Jakura limestone was also found to be first order reaction with respect to CaCO3 ..... Kinetics and Reactor Design, Gulp.

  2. the use of limestone powder as an alternative cement replacement ...

    African Journals Online (AJOL)

    user

    properties of cement paste and hardened mortar in two ranges of blain fineness .... shrinkage as compared to siliceous additives. It is ... 100LSF (Lime. Saturation Factor) ..... production of Portland limestone cement were free from impurities or ...

  3. Stabilization of chloro-organics using organophilic bentonite in a cement-blast furnace slag matrix.

    Science.gov (United States)

    Cioffi, R; Maffucci, L; Santoro, L; Glasser, F P

    2001-01-01

    The application of cement-based stabilisation/solidification treatment to organic-containing wastes is made difficult by the adverse effect of organics on cement hydration. The use of organophilic clays as pre-solidification adsorbents of the organic compounds can reduce this problem because of the high adsorption power of these clays and their compatibility with the cementitious matrix. This work presents an investigation of the effect on hydration kinetics, physico-mechanical properties and leaching behaviour of cement-based solidified waste forms containing 2-chlorophenol and 1-chloronapthalene adsorbed on organophilic bentonites. These were prepared by cation exchange with benzyldimethyloctadecylammonium chloride and trimethyloctadecylammonium chloride. The binder was a 30% pozzolanic cement, 70% granulated blast furnace slag mixture. Several binder-to-bentonite ratios and different concentrations of the organics on the bentonite were used. Kinetics of hydration were studied by measurement of chemically bound water and by means of thermal and calorimetric analyses. Microstructure and other physico-mechanical properties of the solidified forms were studied by means of mercury intrusion porosimetry, scanning electron microscopy and unconfined compressive strength measurement. Leaching was checked by two different leaching tests: one dynamic, on monolithic samples, and the other static, on powdered samples. This study indicates that the incorporation of the organic-loaded bentonite in the binder matrix causes modifications in the hardened samples by altering cement hydration. The effects of the two organic contaminants are differentiated.

  4. Boron removal from molten silicon using sodium-based slags

    Institute of Scientific and Technical Information of China (English)

    Yin Changhao; Hu Bingfeng; Huang Xinming

    2011-01-01

    Slag refining,as an important option for boron removal to produce solar grade silicon (SOG-Si) from metallurgical grade silicon (MG-Si),has attracted increasing attention.In this paper,Na2CO3-SiO2 systems were chosen as the sodium-based refining slag materials for boron removal from molten silicon.Furthermore,the effect of Al2O3 addition for boron removal was studied in detail,which showed that an appropriate amount of Al2O3 can help retention of the basicity of the slags,hence improving the boron removal rate.

  5. Study on Apparent Viscosity and Structure of Foaming Slag

    Science.gov (United States)

    Martinsson, Johan; Glaser, Björn; Sichen, Du

    2016-10-01

    Foaming slag was generated using induction heating. The foam was found non-Newtonian having much higher apparent viscosity compared to the dynamic viscosity of pure slag. Quenched foam was examined. The appearance of the foaming slag was very different from silicone oil-gas foam. The size of gas bubbles ranged from 0.1 to 4 mm (while in the case of silicone oil, 1 to 2 mm). The gas fraction in the foam was considerably lower than in the case of silicone oil.

  6. Optimizing of Work Arc Furnace to Decopperisation of Flash Slag

    Directory of Open Access Journals (Sweden)

    Bydałek A.W.

    2015-09-01

    Full Text Available Discusses an attempt to optimize the operation of an electric furnace slag to be decopperisation suspension of the internal recycling process for the production of copper. The paper presents a new method to recover copper from metallurgical slags in arc-resistance electric furnace. It involves the use of alternating current for a first period reduction, constant or pulsed DC in the final stage of processing. Even distribution of the electric field density in the final phase of melting caused to achieve an extremely low content of metallic copper in the slag phase. They achieved by including the economic effects by reducing the time reduction.

  7. Facies patterns and depositional environments of Palaeozoic cephalopod limestones

    Science.gov (United States)

    Wendt, J.; Aigner, T.

    1985-07-01

    In the eastern Anti-Atlas (Morocco) a platform and basin topography was established during the late Devonian, probably as a result of early Variscan tensional tectonics. Cephalopod limestones were deposited on shallow pelagic platforms, platform slopes and shallow, slowly subsiding basins. On the platform a transition from land areas into nearshore quartzose brachiopod coquinas, crinoidal limestones, condensed cephalopod limestones and finally into nodular limestones is observed. The latter often become disintegrated into incipient debris flows which pass into nodular limestone/marl alternations of a shallow basin. Deeper basins with shale sedimentation lack cephalopod limestones. Similar facies types also occur in the late Devonian of the Montagne Noire (France), Rheinisches Schiefergebirge (West Germany), Moravian Karst (Czechoslovakia), Holy Cross Mountains (Poland) and in the early Carboniferous of the Cantabrian Mountains (Spain). Due to strong late Variscan compressional tectonics and limited outcrops, detailed facies patterns could not be mapped in these regions, but the same facies types as in the eastern Anti-Atlas suggest similar coast/platform, slope and shallow basin topographies. During cephalopod limestone deposition water depth on the platforms was in the order of several tens to about one hundred metres, as is inferred from repeated subaerial exposures and distinctive depositional and faunal/floral features. Water depth in the adjacent shallow basins might have reached several hundreds of metres. Cephalopod limestones represent a typical stage in the evolution of geosynclines, characterized by extremely low sedimentation rates (1-5 m m.y. -1). This stage is preceded by deposition of thick neritic clastics and/or carbonates and is succeeded by deposition of deep-water clastics or flysch.

  8. An approach for phosphate removal with quartz sand, ceramsite, blast furnace slag and steel slag as seed crystal.

    Science.gov (United States)

    Qiu, Liping; Wang, Guangwei; Zhang, Shoubin; Yang, Zhongxi; Li, Yanbo

    2012-01-01

    The phosphate removal abilities and crystallization performance of quartz sand, ceramsite, blast furnace slag and steel slag were investigated. The residual phosphate concentrations in the reaction solutions were not changed by addition of the ceramsite, quartz sand and blast furnace slag. The steel slag could provide alkalinity and Ca(2+) to the reaction solution due to its hydration activity, and performed a better phosphate removal performance than the other three. Under the conditions of Ca/P 2.0, pH 8.5 and 10 mg P/L, the phosphate crystallization occurred during 12 h. The quartz sand and ceramsite did not improve the phosphate crystallization, but steel slag was an effective seed crystal. The phosphate concentration decreased drastically after 12 h after addition of steel slag, and near complete removal was achieved after 48 h. The XRD analysis showed that the main crystallization products were hydroxyapatite (HAP) and the crystallinity increased with the reaction time. Phosphate was successfully recovered from low phosphate concentration wastewater using steel slag as seed material.

  9. Effect of P2O5 and FetO on the Viscosity and Slag Structure in Steelmaking Slags

    Science.gov (United States)

    Wang, Z. J.; Shu, Q. F.; Sridhar, S.; Zhang, M.; Guo, M.; Zhang, Z. T.

    2015-04-01

    The present paper investigates the influence of P2O5 and FetO on the viscosity and structure of steelmaking slags. An understanding of the viscous behavior and structure of FetO-bearing smelting slags is essential to control the dephosphorization in steelmaking process and to efficiently recycle the phosphorus from steelmaking slags. It is found that the viscosity of CaO-SiO2-Al2O3-MgO-FetO-P2O5 slags slightly increases with increasing P2O5 content, while the viscosity decreases with increasing FetO content. The degree of the polymerization of quenched slags, determined from Raman spectra, is found to increase with increasing P2O5 content and decrease with increasing FetO content. It is also noted that the peaks of Raman spectra between 800 and 1200 cm-1 were nearly absent at the FetO content of 22.46 wt pct; whereas according to 29Si MAS-NMR and FTIR analysis, it is clearly seen that the [SiO4]-tetrahedra-related peaks existed even for the same slag. This may confirm that small quantities of extra-framework iron species can absorb the Raman scattering and damp the Raman signal intensity and the presence of FetO in the slag does not necessarily eliminate [SiO4]-tetrahedra.

  10. A Metagenomic Survey of Limestone Hill in Taiwan

    Science.gov (United States)

    Hsu, Y. W.; Li, K. Y.; Chen, Y. W.; Huang, T. Y.; Chen, W. J.; Shih, Y. J.; Chen, J. S.; Fan, C. W.; Hsu, B. M.

    2016-12-01

    The limestone of Narro-Sky in Tainliao, Taiwan is of Pleistocene reef limestones interbedded in clastic layers that covered the Takangshan anticlines. Understanding how microbial relative abundance was changed in response to changes of environmental factors may contribute to better comprehension of roles that microorganisms play in altering the landscape structures. In this study, microorganisms growing on the wall of limestone, in the water dripping from the limestone wall and of soil underneath the wall were collected from different locations where the environmental factors such as daytime illumination, humidity, or pH are different. Next generation sequencing (NGS) was carried out to examine the compositions and richness of microbial community. The metagenomics were clustered into operational taxonomic units (OTUs) to analyze relative abundance, diversities and principal coordinates analysis (PCoA). Our results showed the soil sample has the highest alpha diversity while water sample has the lowest. Four major phyla, which are Proteobacteria, Acidobacteria, Actinobacteria, and Cyanobacteria, account for 80 % of total microbial biomass in all groups. Cyanobacteria were found most abundantly in limestone wall instead of water or soil of weathering limestone. The PCoA dimensional patterns of each phylum showed a trace of microbial community dynamic changes, which might be affected by environmental factors. This study provides the insights to understand how environmental factors worked together with microbial community to shape landscape structures.

  11. Converting SDAP into gypsum in a wet limestone scrubber

    Energy Technology Data Exchange (ETDEWEB)

    Fogh, F. [Faelleskemikerne, Elsamprojekt A/S, Fredericia (Denmark)

    1996-12-01

    The ELSAM power pool has an installed electrical capacity of approx. 5 GW{sub e}, mainly firing import coal. The major base load units are equipped with desulphurization units and three different desulphurization technologies are used: the wet limestone gypsum process, the spray dry absorption process and a sulphuric acid process. Gypsum and sulphuric acid are commercialized, whereas it has been difficult to utilize the spray dry absorption product (SDAP). The main constituents of SDAP are calcium sulphide, calcium chloride, hydrated lime and impurities mainly originating from fly ash. Sulphide can be oxidized into sulphate in acidic solution - the reaction is utilized in the wet limestone gypsum process - and the possibility of using any spare capacity in the wet limestone gypsum units to oxidize the sulphide content of SDAP into sulphate and produce usable gypsum has been investigated in the laboratory and in a 400 MW{sub e} equivalent wet limestone unit. The limestone inhibition effect of the addition of SDAP is currently being studied in the laboratory in order to determine the effect of different SDAP types (plant/coal sources) on limestone reactivity before further long-term full-scale tests are performed and permanent use of the process planned. (EG)

  12. Modeling the influence of limestone addition on cement hydration

    Directory of Open Access Journals (Sweden)

    Ashraf Ragab Mohamed

    2015-03-01

    Full Text Available This paper addresses the influence of using Portland limestone cement “PLC” on cement hydration by characterization of its microstructure development. The European Standard EN 197-1:2011 and Egyptian specification ESS 4756-1/2009 permit the cement to contain up to 20% ground limestone. The computational tools assist in better understanding the influence of limestone additions on cement hydration and microstructure development to facilitate the acceptance of these more economical and ecological materials. μic model has been developed to enable the modeling of microstructural evolution of cementitious materials. In this research μic model is used to simulate both the influence of limestone as fine filler, providing additional surfaces for the nucleation and growth of hydration products. Limestone powder also reacts relatively slow with hydrating cement to form monocarboaluminate (AFmc phase, similar to the mono-sulfoaluminate (AFm phase formed in ordinary Portland cement. The model results reveal that limestone cement has accelerated cement hydration rate, previous experimental results and computer model “cemhyd3d” are used to validate this model.

  13. Clay membrane made of natural high plasticity clay:

    DEFF Research Database (Denmark)

    Foged, Niels; Baumann, Jens

    1999-01-01

    -type. The clay material has been evaluated using the standardized methods related to mineralogy, classification, compaction and permeability, and initial studies of diffusion properties have been carried out. Furthermore, at a test site the construction methods for establishing a 0.15-0.3 m thick clay membrane...... have been tested successfully. At a natural water content of w=40-45% it is possible to establish a homogeneous membrane with hydraulic conductivity k...

  14. The behavior of sulfur in industrial pyrometallurgical slags

    Science.gov (United States)

    Nagamori, Meguru

    1994-08-01

    Dissolution of sulfur in industrial slags, even at such a low level as 1 mass% S or so, increases the solubility of certain valuable metals by an order of magnitude. The phenomenon is accounted for in terms of Flood-Førland-Grjotheim's model for dianionic salt solutions, whereas its rigorous analysis requires the digaseous Gibbs-Duhem integration. In the research described here, the distribution of sulfur among gas, slag, and metallic iron phases in the bath smelting of iron ore was computer-simulated based on a two-sites model coupled with sulfide capacity data. The solubilities of Ag, Cu, Co, and Ni in industrial slags are reviewed by applying the sulfidic-oxidic dissolution model to copper-matte smelting, nickel-slag cleaning (Falconbridge, Canada), and the imperial smelting process for zinc and lead (Hachinohe, Japan).

  15. Removal of phosphate from aqueous solution with blast furnace slag.

    Science.gov (United States)

    Oguz, Ensar

    2004-10-18

    Blast furnace slag was used to remove phosphate from aqueous solutions. The influence of pH, temperature, agitation rate, and blast furnace slag dosage on phosphate removal was investigated by conducting a series of batch adsorption experiments. In addition, the yield and mechanisms of phosphate removal were explained on the basis of the results of X-ray spectroscopy, measurements of zeta potential of particles, specific surface area, and images of scanning electron microscopy (SEM) of the particles before and after adsorption. The specific surface area of the blast furnace slag was 0.4m(2)g(-1). The removal of phosphate predominantly has taken place by a precipitation mechanism and weak physical interactions between the surface of adsorbent and the metallic salts of phosphate. In this study, phosphate removal in excess of 99% was obtained, and it was concluded that blast furnace slag is an efficient adsorbent for the removal of phosphate from solution.

  16. Reduction and foaming of FeO containing slag

    Energy Technology Data Exchange (ETDEWEB)

    Galgali, R.K.; Datta, P.; Ray, A.K.; Prasad, K.K.; Ray, H.S. [Regional Research Lab., Orissa (India)

    2001-07-01

    Smelting reduction processes being developed for producing liquid iron using coal and oxygen are attractive because they allow the use of ore fines directly and do not depend on coke. This paper presents a brief review of some aspects of smelting reduction and some results of an experimental investigation carried out on the reduction of 5-20 wt-% FeO in a synthetically prepared slag by various reductants in a plasma reactor. Some results of a simulation of the smelting reduction process by carrying out post-combustion with oxygen lancing over the slag surface are also presented. It has been possible to achieve a steady state condition, namely, 1-2 wt-% FeO in the slag with a slag height of 4-5 cm during periodic addition of a charge consisting of iron ore, coal, and flux. A kinetic analysis of FeO reduction with various reductants is presented in detail.

  17. Vaporization Studies from Slag Surfaces Using a Thin Film Technique

    Science.gov (United States)

    Seetharaman, Seshadri; Shyrokykh, Tetiana; Schröder, Christina; Scheller, Piotr R.

    2013-08-01

    The investigations of vanadium vaporization from CaO-SiO2-FeO-V2O5 thin film slags were conducted using the single hot thermocouple technique (SHTT) with air as the oxidizing atmosphere. The slag samples were analyzed after the experiments by SEM/EDX. The vanadium content was found to decrease as a function of time. The loss of vanadium from the slag film after 30 minutes of oxidation was approximately 18 pct and after 50 minutes, it was nearly 56 pct. The possible mechanism of vanadium loss would be the surface oxidation of vanadium oxide in the slag, VO x to V5+, followed by surface evaporation of V2O5, which has a high vapor pressure at the experimental temperature.

  18. Properties of Industrial Slag as Fine Aggregate in Concrete

    Directory of Open Access Journals (Sweden)

    A. Ananthi

    2015-04-01

    Full Text Available The main objective of this paper is to use the industrial waste such as bottom ash and Weld Slag (WS as the partial replacement for fine aggregates in concrete. This paper presents the chemical analysis and strength properties of industrial solid waste such as bottom ash, weld slag 1 (WS 1 and weld slag 2 (WS 2. Their chemical compositions were identified by X-ray powder diffraction (XRD analysis. The qualitative and quantitative elemental analysis of the bottom ash and weld slag was recognized by energy dispersive X-ray analysis and their morphology were studied by Scanning Electron Microscope (SEM. The compressive strength of concrete with 10% replacement of fine aggregate to the industrial waste shows higher strength than the normal concrete and hence this industrial waste can be used as fine aggregate in concrete.

  19. Activity of Reducing Steel Slag of EAF

    Institute of Scientific and Technical Information of China (English)

    GUO Chinhsiang; HWANG Chaolung; LIN Tingyi

    2011-01-01

    Reducing steel slag (RSS) was mainly acquired from five electric-arc furnace (EAF)steelmaking plants (among them, the products of two plants were carbon steel and those of other plants were stainless steel) for research tests. The chemical properties, compound compositions, activities and contents of main expansive compounds were tested. The results showed that the field sampled RSS had a very high crystallinity and hydraulicity with main chemical compositions close to those of Portland cement. It can be known from the study that in case of C/S ratio higher than 2.0, the main compound compositions are C2S, C3S, C2F and f-CaO. However, after the RSS was stored for six months, an obvious variation occurred with potential pre-hydration in RSS, where the SO3 content was slightly reduced and the compressive activity index was obviously higher than that at the 28th day.

  20. Experimental Investigation and Modeling of Copper Smelting Slags

    Science.gov (United States)

    Starodub, Konstantin; Kuminova, Yaroslava; Dinsdale, Alan; Cheverikin, Vladimir; Filichkina, Vera; Saynazarov, Abdukahhar; Khvan, Alexandra; Kondratiev, Alex

    2016-10-01

    Effective extraction of copper from sulfide ores requires careful operation of a copper smelter, which in turn depends very much on chemistry of the feed and resulted slag and matte. For example, chemical composition of copper smelting slags has to be in a certain range to ensure that their properties are within specific limits. Disobeying these rules may lead to complications in smelting operation, poor quality of the copper products, and premature shutdown of the copper smelter. In the present paper the microstructure and phase composition of slags from the Almalyk copper flash smelter were investigated experimentally and then modeled thermodynamically to evaluate potential ways of improvement and optimization of the copper smelting process and its products. The slag samples were taken at different stages of the copper smelting process: on slag tapping, after slag transportation to a deposition site, and at the site. Experimental investigation included the XRD, XRF, and SEM techniques, which were also confirmed by the traditional wet chemistry analysis. Thermodynamic modeling was carried out using thermochemical software package MTDATA, which enables thermodynamic and physical properties of the matte, slag, and gas phases to be calculated in a wide range of temperatures, pressures, and chemical compositions. In addition, slag viscosities and corresponding matte settling rates were estimated using the modified Urbain and Utigard-Warczok models, and the Hadamard-Rybczynski equation, respectively. It was found that the copper content in the slags may vary significantly depending on the location of slag sampling. Cu was found to be present as sulfide particles, almost no Cu was found to be dissolved in the slag. Analysis of microstructure and phase composition showed that major phase found in the samples is fayalite, while other phases are complex spinels (based on magnetite), different sulfides, and a glass-like phase. Thermodynamic calculations demonstrated the

  1. ALKALI-ACTIVATED CEMENT MORTARS CONTAINING RECYCLED CLAY-BASED CONSTRUCTION AND DEMOLITION WASTE

    Directory of Open Access Journals (Sweden)

    F. Puertas

    2015-09-01

    Full Text Available The use of clay-based waste as an aggregate for concrete production is an amply studied procedure. Nonetheless, research on the use of this recycled aggregate to prepare alkaline cement mortars and concretes has yet to be forthcoming. The present study aimed to determine: the behaviour of this waste as a pozzolan in OPC systems, the mechanical strength in OPC, alkali-activated slag (AAS and fly ash (AAFA mortars and the effect of partial replacement of the slag and ash themselves with ground fractions of the waste. The pozzolanic behaviour of clay-based waste was confirmed. Replacing up to 20 % of siliceous aggregate with waste aggregate in OPC mortars induced a decline in 7 day strength (around 23 wt. %. The behaviour of waste aggregate in AAMs mortars, in turn, was observed to depend on the nature of the aluminosilicate and the replacement ratio used. When 20 % of siliceous aggregate was replaced by waste aggregate in AAS mortars, the 7 day strength values remained the same (40 MPa. In AAFA mortars, waste was found to effectively replace both the fly ash and the aggregate. The highest strength for AAFA mortars was observed when they were prepared with both a 50 % replacement ratio for the ash and a 20 % ratio for the aggregate.

  2. Desulfurization ability of refining slag with medium basicity

    Science.gov (United States)

    Yu, Hui-xiang; Wang, Xin-hua; Wang, Mao; Wang, Wan-jun

    2014-12-01

    The desulfurization ability of refining slag with relative lower basicity ( B) and Al2O3 content ( B = 3.5-5.0; 20wt%-25wt% Al2O3) was studied. Firstly, the component activities and sulfide capacity ( C S) of the slag were calculated. Then slag-metal equilibrium experiments were carried out to measure the equilibrium sulfur distribution ( L S). Based on the laboratorial experiments, slag composition was optimized for a better desulfurization ability, which was verified by industrial trials in a steel plant. The obtained results indicated that an MgO-saturated CaO-Al2O3-SiO2-MgO system with the basicity of about 3.5-5.0 and the Al2O3 content in the range of 20wt%-25wt% has high activity of CaO ( a CaO), with no deterioration of C S compared with conventional desulfurization slag. The measured L S between high-strength low-alloyed (HSLA) steel and slag with a basicity of about 3.5 and an Al2O3 content of about 20wt% and between HSLA steel and slag with a basicity of about 5.0 and an Al2O3 content of about 25wt% is 350 and 275, respectively. The new slag with a basicity of about 3.5-5.0 and an Al2O3 content of about 20wt% has strong desulfurization ability. In particular, the key for high-efficiency desulfurization is to keep oxygen potential in the reaction system as low as possible, which was also verified by industrial trials.

  3. Slagging and Fouling Characteristics of HRSG for Ferrosilicon Electric Furnaces

    OpenAIRE

    2015-01-01

    The slagging and fouling characteristics of the heat recovery steam generator (HRSG) for ferrosilicon electric furnaces are discussed in this paper. Three ash samples were taken from the HRSG of a ferrosilicon furnace in Ningxia Province, China, which suffered from serious slagging and fouling. X-ray fluorescence (XRF), X-ray powder diffraction (XRD) and scanning electron microscope (SEM) were used to analyze the ash samples. The results show that low melting point salt Na 2 SO 4 and composit...

  4. Preparation of Glass Ceramic Based on Granulated Slag and Cullet

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The glass-ceramic was prepared on the basis of materials of granulated slag containing high-calcium oxide and cullet.The content of granulated slag ranges from 50%-60%wt in the glass compositions. The samples were analyzed by DTA, SEM and XRD.The results show that the main crystal phase of the glass-ceramic is β-CaSiO3,Which is in scattering fiber or column form.The applying properties have also been measured.

  5. Constitutive model for overconsolidated clays

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Based on the relationships between the Hvorslev envelope,the current yield sur-face and the reference yield surface,a new constitutive model for overconsolidated clays is proposed. It adopts the unified hardening parameter,to which the potential failure stress ratio and the characteristic state stress ratio are introduced. The model can describe many characteristics of overconsolidated clays,including stress-strain relationships,strain hardening and softening,stress dilatancy,and stress path dependency. Compared with the Cam-clay model,the model only re-quires one additional soil parameter which is the slope of the Hvorslev envelope. Comparisons with data from triaxial drained compression tests for Fujinomori clay show that the proposed model can rationally describe overconsolidated properties. In addition,the model is also used to predict the stress-strain relationship in the isotropic consolidation condition and the stress paths in the undrained triaxial compression tests.

  6. Colloidal gels: Clay goes patchy

    Science.gov (United States)

    Kegel, Willem K.; Lekkerkerker, Henk N. W.

    2011-01-01

    Empty liquids and equilibrium gels have so far been only theoretical possibilities, predicted for colloids with patchy interactions. But evidence of both has now been found in Laponite, a widely studied clay.

  7. An Investigation into the Mechanics of Windblown Dust Entrainment from Nickel Slag Surfaces Resembling Armoured Desert Pavements

    Science.gov (United States)

    Sanderson, Robert Steven

    The purpose of this thesis is to investigate the dynamics of PM 10 emission from a nickel slag stockpile that closely resembles a desert pavement in physical characteristics. In the field, it was observed that slag surfaces develop by natural processes into a well-armoured surface over some period of time. The surface then consists of two distinct layers; a surficial armour layer containing only non-erodible gravel and cobble-sized clasts, and an underlying dust-laden layer, which contains a wide size range of slag particles, from clay-sized to cobble-sized. This surficial armour layer protects the underlying fines from wind entrainment, at least under typical wind conditions; however, particle emissions still do occur under high wind speeds. The dynamics of particle entrainment from within these surfaces are investigated herein. It is shown that the dynamics of the boundary layer flow over these lag surfaces are influenced by the inherent roughness and permeability of the surficial armour layer, such that the flow resembles those observed over and within vegetation canopies, and those associated with permeable gravel-bed river channels. Restriction of air flow within the permeable surface produces a high-pressure zone within the pore spaces, resulting in a Kelvin-Helmholtz shear instability, which triggers coherent motions in the form of repeating burst-sweep cycles. Using Laser Doppler Anemometry (LDA), it is demonstrated that the lower boundary layer is characterized by both Q4 sweeping motions and Q2 bursting motions, while the upper boundary layer is dominated by Q2 bursts. Pore air motions within the slag material were measured using buried pressure ports. It is shown that the mean pressure gradient which forms within the slag material results in net upward displacement of air, or wind pumping. However, this net upward motion is a result of rapid oscillatory motions which are directly driven by coherent boundary layer motions. It is also demonstrated that

  8. Effect of Crushed Air-cooled Blast Furnace Slag on Mechanical Properties of Concrete

    Institute of Scientific and Technical Information of China (English)

    WANG Aiguo; DENG Min; SUN Daosheng; LI Bing; TANG Mingshu

    2012-01-01

    Morphology characteristics of mix aggregates with crushed air-cooled blast furnace slag (SCR) and crushed limestone (LCR) with 5-20 mm and 20-40 mm gradation were represented by numerical parameters including angularity number (AN) and index of aggregate particle shape and texture (IAPST).The effect of mix aggregates containing SCR on compressive strength and splitting tensile strength of concrete was investigated.Fracture characteristics of concrete,interfacial structure between aggregates and matrix were analyzed.The experimental results show that porous and rough SCR increases contact area with matrix in concrete,concave holes and micro-pores on the surface of SCR are filled by mortar and hydrated cement paste,which may increase interlocking and mechanical bond between aggregate and matrix in concrete.SCR can be used to produce a high-strength concrete with better mechanical properties than corresponding concrete made with LCR.The increase of AN and IAPST of aggregate may enhance mechanical properties of concrete.

  9. Porosity Investigation of Kosova's Clay

    OpenAIRE

    Makfire Sadiku; Naim Hasani; Altin Mele

    2011-01-01

    Problem statement: Acid activated clay minerals are used as catalysts in the desulphurization of crude oil or as catalyst carrier, as drilling mud, as bleaching earth. Approach: The efficiency of the acid activation can be described in two ways. As increase of the surface and as increase of the cumulative pore volume after the activation. Results: In different samples of the clay mineral the activation was done with different sulfuric acid concentrations for two and 3h. Afterwards the specifi...

  10. Clays in radioactive waste disposal

    OpenAIRE

    Delage, Pierre; Cui, Yu-Jun; Tang, Anh-Minh

    2010-01-01

    Clays and argillites are considered in some countries as possible host rocks for nuclear waste disposal at great depth. The use of compacted swelling clays as engineered barriers is also considered within the framework of the multi-barrier concept. In relation to these concepts, various research programs have been conducted to assess the thermo-hydro-mechanical properties of radioactive waste disposal at great depth. After introducing the concepts of waste isolation developed in Belgium, Fran...

  11. Characterization of limestone reacted with acid-mine drainage in a pulsed limestone bed treatment system at the Friendship Hill National Historical Site, Pennsylvania, USA

    Energy Technology Data Exchange (ETDEWEB)

    Hammarstrom, J.M.; Sibrell, P.L.; Belkin, H.E. [US Geological Survey, Reston, VA (United States)

    2003-11-01

    Armoring of limestone is a common cause of failure in limestone-based acid-mine drainage (AMD) treatment systems. Limestone is the least expensive material available for acid neutralization, but is not typically recommended for highly acidic, Fe-rich waters due to armoring with Fe(III) oxyhydroxide coatings. A new AMD treatment technology that uses CO{sub 2} in a pulsed limestone bed reactor minimizes armor formation and enhances limestone reaction with AMD. Limestone was characterized before and after treatment with constant flow and with the new pulsed limestone bed process using AMD from an inactive coal mine in Pennsylvania (pH = 2.9, Fe = 150 mg/l, acidity 1000 mg/l CaCO{sub 3}). In constant flow experiments, limestone is completely armored with reddish-colored ochre within 48 h of contact in a fluidized bed reactor. Effluent pH initially increased from the inflow pH of 2.9 to over 7, but then decreased to {lt}4 during the 48 h of contact. Limestone grains developed a rind of gypsum encapsulated by a 10- to 30-mum thick, Fe-Al hydroxysulfate coating. Armoring slowed the reaction and prevented the limestone from generating any additional alkalinity in the system. With the pulsed flow limestone bed process, armor formation is largely suppressed and most limestone grains completely dissolve resulting in an effluent pH of {gt}6 during operation. Limestone removed from a pulsed bed pilot plant is a mixture of unarmored, rounded and etched limestone grains and partially armored limestone and refractory mineral grains (dolomite, pyrite). Aluminium-rich zones developed in the interior parts of armor rims in both the constant flow and pulsed limestone bed experiments in response to pH changes at the solid/solution interface.

  12. Chloride ion transport performance in slag mortar under fatigue loading

    Institute of Scientific and Technical Information of China (English)

    WANG CaiHui; SUN Wei; JIANG JinYang; HAN JianDe; YE BangTu

    2012-01-01

    The transport performance of chloride ion in slag cement mortar was investigated experimentally.In the self-designed experiment,fatigue loading was coupled simultaneously with ion transportation process,the diffusion law of chloride ion was obtained by titration and the AE (acoustic emission) technique was employed to detect the real-time damage distribution in the mortar specimen.The results for fatigue stress levels of 0.3,0.4 and 0.5 and slag contents of 0,10%,30% and 50% showed that fatigue loading accelerated the diffusion of chloride ion in mortar and the acceleration effect increased with the increase in stress levels.Slag addition was found to improve anti-chloride ion erosion performance effectively with the best substitution level at 30%,because the inhibition effect of slag on chloride ion diffusion diminished when the slag content exceeded 30%.The comparative experiments indicated that dynamic load has a significant effect on the transport performance of chloride ion in slag cement mortar.

  13. Stabilization of Black Cotton Soil Using Micro-fine Slag

    Science.gov (United States)

    Shukla, Rajesh Prasad; Parihar, Niraj Singh

    2016-09-01

    This work presents the results of laboratory tests conducted on black cotton soil mixed with micro-fine slag. Different proportions of micro-fine slag, i.e., 3, 6, 9, 12 and 15 % were mixed with the black cotton soil to improve soil characteristics. The improvement in the characteristics of stabilized soil was assessed by evaluating the changes in the physical and strength parameters of the soil, namely, the Atterberg limits, free swell, the California Bearing Ratio (CBR), compaction parameters and Unconfined Compressive Strength (UCS). The mixing of micro-fine slag decreases the liquid limit, plasticity index and Optimum Moisture Contents (OMC) of the soil. Micro-fine slag significantly increases the plastic limit, UCS and CBR of the soil up to 6-7 % mixing, but mixing of more slag led to decrease in the UCS and CBR of the soil. The unsoaked CBR increased by a substantial amount unlike soaked CBR value. The swell potential of the soil is reduced from medium to very low. The optimum amount of micro-fine slag is found to be approximately 6-7 % by the weight of the soil.

  14. Growth promotion effect of steelmaking slag on Spirulina platensis

    Science.gov (United States)

    Nogami, R.; Tam, L. T.; Anh, H. T. L.; Quynh, H. T. H.; Thom, L. T.; Nhat, P. V.; Thu, N. T. H.; Hong, D. D.; Wakisaka, M.

    2016-04-01

    A growth promotion effect of steelmaking slag on Spirulina platensis M135 was investigated. The growth promotion effect was obtained that was 1.27 times greater than that obtained by the control by adding 500 mg L-1 of steelmaking slag and culturing for 60 days. The lipid content decreased in a concentration-dependent manner with steelmaking slag, whereas the carbohydrate content remained constant. The protein content of S. platensis M135 increased in a concentration-dependent manner with steelmaking slag when cultured at day 45. The superoxide dismutase activity of S. platensis M135 exhibited a decreasing trend in a time-dependent manner and an increasing trend in the control. The superoxide dismutase activity was lower than that of the control at day 1 but was higher at day 30. No genetic damage was observed up to 500 mg L-1 of steelmaking slag at 30 days of culture. Recovery from genetic damage was observed at 1,000 mg L-1 of steelmaking slag but not at higher concentrations.

  15. Recovery of copper and cobalt from ancient slag.

    Science.gov (United States)

    Bulut, Gülay

    2006-04-01

    About 2.5 million tonnes of copper smelter slag are available in Küre, northern part of Turkey. This slag contains large amounts of metallic values such as copper and cobalt. A representative slag sample containing 0.98% Cu, 0.49% Co and 51.47% Fe was used in the experimental studies. Two different methods, direct acid leaching and acid baking followed by hot water leaching were used for recovering Cu and Co from the slag. The effects of leaching time, temperature and acid concentration on Cu- and Co-dissolving efficiencies were investigated in the direct acid leaching tests. The optimum leaching conditions were found to be a leaching time of 2 h, acid concentration of 120 g L(-1), and temperature of 60 degrees C. Under these conditions, 78% Cu and 90% Co were extracted. In the acid baking + hot water leaching tests, 74% Co was dissolved after 1 h of roasting at 200 degrees C using a 3:1 acid:slag ratio, whereas the Cu-dissolving efficiency was 79% and the total slag weight loss was approximately 50%.

  16. Effect of factors on the extraction of boron from slags

    Science.gov (United States)

    Zhang, Peixin; Sui, Zhitong

    1995-04-01

    The effects of slag composition, additive agent, and heat treatment on the crystal morphologies, the crystallization behavior, and the efficiency of extraction of boron (EEB) from slags were investigated by chemical analysis, polarization microscope, and X-ray diffraction (XRD) as well as differential thermal analysis (DTA). The EEB varied with the slag composition. The farther the slag composition deviated from the line between 2MgO · B2O3 and 2MgO · SiO2 in the MgO-B2O3-SiO2 system, the lower the EEB. The EEB was directly related to the precipitating characteristics of the boron component in the slags. The EEB was high if the boron component existed in the form of a crystalline phase, otherwise the EEB was low when boron was in the form of an amorphous phase. The EEB from MgO-Al2O3-CaO-B2O3-SiO2 slag varied with the temperature of heat treatment; the highest EEB appeared at 1100 °C. The EEB and the crystallinities were increased by addition of TiO2 and MOx (M = Mg, Ca, Fe, Si). The effect of MOx was more notable than that of TiO2.

  17. What makes a natural clay antibacterial?

    Science.gov (United States)

    Williams, Lynda B.; Metge, David W.; Eberl, Dennis D.; Harvey, Ronald W.; Turner, Amanda G.; Prapaipong, Panjai; Port-Peterson, Amisha T.

    2011-01-01

    Natural clays have been used in ancient and modern medicine, but the mechanism(s) that make certain clays lethal against bacterial pathogens has not been identified. We have compared the depositional environments, mineralogies, and chemistries of clays that exhibit antibacterial effects on a broad spectrum of human pathogens including antibiotic resistant strains. Natural antibacterial clays contain nanoscale (2+ solubility.

  18. Portland cement-blast furnace slag blends in oilwell cementing applications

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, D.T.; DiLullo, G.; Hibbeler, J. [and others

    1995-12-31

    Recent investigations of blast furnace slag cementing technologies. have been expanded to include Portland cement/blast furnace slag blends. Mixtures of Portland cement and blast furnace slag, while having a long history of use in the construction industry, have not been used extensively in oilwell cementing applications. Test results indicate that blending blast furnace slag with Portland cement produces a high quality well cementing material. Presented are the design guidelines and laboratory test data relative to mixtures of blast furnace slag and Portland cements. Case histories delineating the use of blast furnace slag - Portland cement blends infield applications are also included.

  19. Wave liquefaction in soils with clay content

    DEFF Research Database (Denmark)

    Kirca, Özgür; Sumer, B. Mutlu; Fredsøe, Jørgen

    2012-01-01

    The paper presents the results of an experimental study of the influence of clay content (in silt-clay and sand-clay mixtures) on liquefaction beneath progressive waves. The experiments showed that the influence of clay content is very significant. Susceptibility of silt to liquefaction...... is increased with increasing clay content, up to 30%, beyond which the mixture of silt and clay is not liquefied. Sand may become prone to liquefaction with the introduction of clay, contrary to the general perception that this type of sediment is normally liquefaction resistant under waves....

  20. 81 FR 31234 - NESHAP for Brick and Structural Clay Products Manufacturing; and NESHAP for Clay Ceramics...

    Science.gov (United States)

    2016-05-18

    ... AGENCY NESHAP for Brick and Structural Clay Products Manufacturing; and NESHAP for Clay Ceramics... Brick and Structural Clay Products (BSCP) Manufacturing and the final NESHAP for Clay Ceramics... No. EPA-HQ-OAR-2013-0290 for Clay Ceramics Manufacturing. All documents in the dockets are listed...

  1. Modifying the properties of finely ground limestone by tumbling granulation

    Science.gov (United States)

    Macho, Oliver; Eckert, Maroš; Tomášová, Barbora; Peciar, Peter; Ščasný, Martin; Fekete, Roman; Peciar, Marián

    2016-06-01

    Calcium carbonate in the form of finely ground limestone is a material that has found its application in a wide range of industries, in the chemical, rubber, agricultural, and paper industries, is used for desulfurization of boilers and other. In civil engineering, ground limestone is used for the production of building materials, plaster and mortar mixtures, as a filler in concrete mixtures, in road construction, and as an essential component of mastic asphalt. This paper deals with examining the modification of the properties of finely ground limestone by the tumbling agglomeration method. It has been shown that the components of concrete with a round grain have a positive effect on the pumping of concrete in comparison with an elongated grain or the rough surface of crushed stone. The experiments will be carried out on a granulation plate using a variety of granulation liquid. The agglomerates and their properties were compared with untreated finely ground limestone, with a focus on detecting changes in compressibility, density and particle size. The output of this paper is a description and graphical representation of the changes in the properties of ground limestone before and after the agglomeration process.

  2. Modifying the properties of finely ground limestone by tumbling granulation

    Directory of Open Access Journals (Sweden)

    Macho Oliver

    2016-06-01

    Full Text Available Calcium carbonate in the form of finely ground limestone is a material that has found its application in a wide range of industries, in the chemical, rubber, agricultural, and paper industries, is used for desulfurization of boilers and other. In civil engineering, ground limestone is used for the production of building materials, plaster and mortar mixtures, as a filler in concrete mixtures, in road construction, and as an essential component of mastic asphalt. This paper deals with examining the modification of the properties of finely ground limestone by the tumbling agglomeration method. It has been shown that the components of concrete with a round grain have a positive effect on the pumping of concrete in comparison with an elongated grain or the rough surface of crushed stone. The experiments will be carried out on a granulation plate using a variety of granulation liquid. The agglomerates and their properties were compared with untreated finely ground limestone, with a focus on detecting changes in compressibility, density and particle size. The output of this paper is a description and graphical representation of the changes in the properties of ground limestone before and after the agglomeration process.

  3. 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

    2017-08-01

    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.

  4. Molybdate adsorption from steel slag eluates by subsoils.

    Science.gov (United States)

    Matern, K; Rennert, T; Mansfeldt, T

    2013-11-01

    Steel slags are industrial by-products which are generated in large amounts worldwide, e.g. 150-230×10(6) Mg in 2012, and which are partly used for construction. Molybdenum (Mo) can be added during steel processing in order to harden the steel. The objective of this study was to evaluate the adsorption behaviour of molybdate (MoO4(2-)) from slag eluates in subsoils. Molybdate batch adsorption experiments were carried out with eluates obtained from two different kinds of steel slags (i) LD slag (Linz-Donawitz operation, LDS) and (ii) electric arc furnace slag (EAF) to assess the risk that may arise from the contamination of groundwater by the leaching of molybdate. Six different subsoils were chosen in order to provide a wide range of chemical properties (pH 4.0-7.6; dithionite-extractable Fe 0.73-14.7 g kg(-1)). Molybdate adsorption experiments were carried out at the pH of the steel slag eluates (pH 11-12) as well as at pH values adjusted to the soil pH. The data were evaluated with the Freundlich equation. Molybdate adsorption exhibited a maximum near pH 4 for steel slag eluates adjusted to the soil pH, and decreased rapidly with increasing pH until adsorption was virtually zero at pH>11. Adsorption was greater for soils with high amounts of dithionite-extractable Fe oxides. The extent and behaviour of molybdate adsorption from both eluates was similar. After a reaction time of 24h, the pH of the EAF slag eluate was lower than that of the LD steel slag eluate, which was caused by different acid buffer capacities. Some soils were able to decrease the pH of the EAF slag eluates by about 4 pH units, enhancing the adsorption of molybdate. Transport simulations indicated that molybdate discharge is low in acidic soils.

  5. How mobile are sorbed cations in clays and clay rocks?

    Science.gov (United States)

    Gimmi, T; Kosakowski, G

    2011-02-15

    Diffusion of cations and other contaminants through clays is of central interest, because clays and clay rocks are widely considered as barrier materials for waste disposal sites. An intriguing experimental observation has been made in this context: Often, the diffusive flux of cations at trace concentrations is much larger and the retardation smaller than expected based on their sorption coefficients. So-called surface diffusion of sorbed cations has been invoked to explain the observations but remains a controversial issue. Moreover, the corresponding surface diffusion coefficients are largely unknown. Here we show that, by an appropriate scaling, published diffusion data covering a broad range of cations, clays, and chemical conditions can all be modeled satisfactorily by a surface diffusion model. The average mobility of sorbed cations seems to be primarily an intrinsic property of each cation that follows inversely its sorption affinity. With these surface mobilities, cation diffusion coefficients can now be estimated from those of water tracers. In pure clays at low salinities, surface diffusion can reduce the cation retardation by a factor of more than 1000.

  6. 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.

  7. Characterization of Ladle Furnace Slag from Carbon Steel Production as a Potential Adsorbent

    Directory of Open Access Journals (Sweden)

    Ankica Rađenović

    2013-01-01

    Full Text Available A promising type of steel slag for applications is the ladle furnace (LF slag, which is also known as the basic slag, the reducing slag, the white slag, and the secondary refining slag. The LF slag is a byproduct from further refining molten steel after coming out of a basic oxygen furnace (BOF or an electric arc furnace (EAF. The use of the LF slag in further applications requires knowledge of its characteristics. The LF slag characterization in this paper has been performed using the following analytical methods: chemical analysis by energy dispersive spectrometry (EDS, mineralogical composition by X-ray diffraction (XRD, surface area properties by the Brunauer-Emmett-Teller (BET and the Barrett-Joyner-Halenda (BJH methods, surface chemistry by infrared absorption (FTIR spectroscopy, and morphological analysis by scanning electron microscopy (SEM. The results showed that the main compounds are calcium, silicon, magnesium, and aluminium oxides, and calcium silicates under their various allotropic forms are the major compounds in the LF slag. Surface area properties have shown that the LF slag is a mesoporous material with relatively great BET surface area. The ladle furnace slag is a nonhazardous industrial waste because the ecotoxicity evaluation by its eluate has shown that the LF slag does not contain constituents which might in any way affect the environment harmfully.

  8. Slagging and Fouling Characteristics of HRSG for Ferrosilicon Electric Furnaces

    Directory of Open Access Journals (Sweden)

    Yungang Wang

    2015-02-01

    Full Text Available The slagging and fouling characteristics of the heat recovery steam generator (HRSG for ferrosilicon electric furnaces are discussed in this paper. Three ash samples were taken from the HRSG of a ferrosilicon furnace in Ningxia Province, China, which suffered from serious slagging and fouling. X-ray fluorescence (XRF, X-ray powder diffraction (XRD and scanning electron microscope (SEM were used to analyze the ash samples. The results show that low melting point salt Na2SO4 and composite salts Na (AlSi3O8 and 3K2SO4·CaSO4 deposit on the superheater tube walls in aerosol form and solidify to form the initial slag layer. With the continuous deposition of the low melting point compounds, more and more ash particles in the flue gas adhere to the slag surface to form a thicker slag. Low melting point composite salt NaO·Al2O3·SiO2 is absorbed on the evaporator tube walls in aerosol form. With the deposition of NaO·Al2O3·SiO2, more and more ash particles are absorbed to form the fouling. Since there is less space between pin-finned tubes, the large iron-rich slag particles are easily deposited on tube walls and fin surfaces, which is advantageous to the fouling process. There are large quantities of superfine ash particles in the flue gas that easily adhere to other particles or tube walls, which facilitates the slagging and fouling process.

  9. Desulfurization ability of refining slag with medium basicity

    Institute of Scientific and Technical Information of China (English)

    Hui-xiang Yu; Xin-hua Wang; Mao Wang; Wan-jun Wang

    2014-01-01

    The desulfurization ability of refining slag with relative lower basicity (B) and Al2O3 content (B=3.5−5.0;20wt%−25wt%Al2O3) was studied. Firstly, the component activities and sulfide capacity (CS) of the slag were calculated. Then slag−metal equilibrium experiments were carried out to measure the equilibrium sulfur distribution (LS). Based on the laboratorial experiments, slag composition was optimized for a better desulfurization ability, which was verified by industrial trials in a steel plant. The obtained results indicated that an MgO-saturated CaO−Al2O3−SiO2−MgO system with the basicity of about 3.5−5.0 and the Al2O3 content in the range of 20wt%−25wt%has high activity of CaO (aCaO), with no deterioration of CS compared with conventional desulfurization slag. The measured LS between high-strength low-alloyed (HSLA) steel and slag with a basicity of about 3.5 and an Al2O3 content of about 20wt%and between HSLA steel and slag with a basicity of about 5.0 and an Al2O3 content of about 25wt%is 350 and 275, respectively. The new slag with a basicity of about 3.5−5.0 and an Al2O3 content of about 20wt%has strong desulfurization ability. In particular, the key for high-efficiency desulfurization is to keep oxygen potential in the reaction system as low as possible, which was also verified by industrial trials.

  10. Charm of Purple Clay A private museum in Wuxi is devoted to purple-clay art

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Purple-clay art pieces will be on display in a museum opening soon in Wuxi, Jiangsu Province. The museum, named Shuaiyuan Purple Clay Museum, is part of the Shuaiyuan Purple Clay Art Exhibition Center

  11. Novel Hydroxyapatite Coatings for the Conservation of Marble and Limestone

    Science.gov (United States)

    Naidu, Sonia

    Marble and limestone are calcite-based materials used in the construction of various structures, many of which have significant artistic and architectural value. Unfortunately, due to calcite's high dissolution rate, these stones are susceptible to chemically-induced weathering in nature. Limestone, due to its inherent porosity, also faces other environmental weathering processes that cause weakening from disintegration at grain boundaries. The treatments presently available are all deficient in one way or another. The aim of this work is to examine the feasibility of using hydroxyapatite (HAP) as a novel protective coating for marble and limestone, with two goals: i) to reduce acid corrosion of marble and ii) to consolidate physically weathered limestone. The motivation for using HAP is its low dissolution rate and structural compatibility with calcite. Mild, wet chemical synthesis routes, in which inorganic phosphate-based solutions were reacted with marble and limestone, alone and with other precursors, were used to produce HAP films. Film nucleation, growth and phase evolution were studied on marble to understand film formation and determine the optimal synthesis route. An acid resistance test was developed to investigate the attack mechanism on marble and quantify the efficacy of HAP-based coatings. Film nucleation and growth were dependent on substrate surface roughness and increased with calcium and carbonate salt additions during synthesis. Acid attack on marble occurred via simultaneous dissolution at grain boundaries, twin boundaries and grain surfaces. HAP provided intermediate protection against acid attack, when compared to two conventional treatments. Its ability to protect the stone from acid was not as significant as predicted from dissolution kinetics and this was attributed to incomplete coverage and residual porosity within the film, arising from its flake-like crystal growth habit, which enabled acid to access the underlying substrate. The

  12. Experimental study on exhaust gas after treatment using limestone

    Directory of Open Access Journals (Sweden)

    Sakhrieh Ahmad

    2013-01-01

    Full Text Available In this study a simple low-cost exhaust gas after-treatment filter using limestone was developed and tested on a four cylinder DI diesel engine coupled with dynamometer under variable engine running conditions. Limestone was placed in cast iron housing through which exhaust gases passes. The concentration of both carbon dioxide and nitrogen oxides were measured with and without the filter in place. It was found that both pollutants were decreased significantly when the filter is in place, with no increase in the fuel consumption rate.

  13. Effect of SO2 Dry Deposition on Porous Dolomitic Limestones

    Science.gov (United States)

    Olaru, Mihaela; Aflori, Magdalena; Simionescu, Bogdana; Doroftei, Florica; Stratulat, Lacramioara

    2010-01-01

    The present study is concerned with the assessment of the relative resistance of a monumental dolomitic limestone (Laspra – Spain) used as building material in stone monuments and submitted to artificial ageing by SO2 dry deposition in the presence of humidity. To investigate the protection efficiency of different polymeric coatings, three commercially available siloxane-based oligomers (Lotexan-N, Silres BS 290 and Tegosivin HL 100) and a newly synthesized hybrid nanocomposite with silsesquioxane units (TMSPMA) were used. A comparative assessment of the data obtained in this study underlines that a better limestone protection was obtained when treated with the hybrid nanocomposite with silsesquioxane units.

  14. Effect of SO2 Dry Deposition on Porous Dolomitic Limestones

    Directory of Open Access Journals (Sweden)

    Florica Doroftei

    2010-01-01

    Full Text Available The present study is concerned with the assessment of the relative resistance of a monumental dolomitic limestone (Laspra – Spain used as building material in stone monuments and submitted to artificial ageing by SO2 dry deposition in the presence of humidity. To investigate the protection efficiency of different polymeric coatings, three commercially available siloxane-based oligomers (Lotexan-N, Silres BS 290 and Tegosivin HL 100 and a newly synthesized hybrid nanocomposite with silsesquioxane units (TMSPMA were used. A comparative assessment of the data obtained in this study underlines that a better limestone protection was obtained when treated with the hybrid nanocomposite with silsesquioxane units.

  15. Initial kinetics of the direct sulfation of limestone

    DEFF Research Database (Denmark)

    Hu, Guilin; Shang, Lei; Dam-Johansen, Kim;

    2008-01-01

    The initial kinetics of direct sulfation of Faxe Bryozo, a porous bryozoan limestone was studied in the temperature interval from 873 to 973 K in a pilot entrained flow reactor with very short reaction times (between 0.1 and 0.6 s). The initial conversion rate of the limestone - for conversions...... ions in calcite grains is established. The validity of the model is limited to the initial sulfation period, in which nucleation of the solid product calcium sulphate is not started. This theoretical reaction-diffusion model gives a good simulation of the initial kinetics of the direct sulfation...

  16. 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.

  17. Influence of Basicity and MgO on Fluidity and Desulfurization Ability of High Aluminum Slag

    Science.gov (United States)

    Wang, Ping; Meng, Qing-min; Long, Hong-ming; Li, Jia-xin

    2016-08-01

    The viscosity of experimental slag, which was mixed based on the composition of a practical blast furnace slag, was measured in this paper. The influence of Al2O3 and MgO content, basicity R2 = w(CaO)/w(SiO2) on the fluidity of slag was studied. The stepwise regression analysis in SPSS was used to reveal the relationship between sulfur distribution coefficient LS and slag composition as well as furnace temperature. The results show that increasing of MgO up to 12% can decrease the slag viscosity. The w(MgO) should be controlled below 8% when there is 20% Al2O3 in the slag. Temperature of hot metal and content of CaO in slag are the two dominant factors on the desulfurization capacity of slag.

  18. Steel Slag as an Iron Fertilizer for Corn Growth and Soil Improvement in a Pot Experiment

    Institute of Scientific and Technical Information of China (English)

    WANG Xian; CAI Qing-Sheng

    2006-01-01

    The feasibility of steel slag used as an iron fertilizer was studied in a pot experiment with corn. Slag alone or acidified slag was added to two Fe-deficient calcareous soils at different rates. Results showed that moderate rates (10 and 20 g kg-1)of slag or acidified slag substantially increased corn dry matter yield and Fe uptake. Application of steel slag increased the residual concentration of ammonium bicarbonate-diethylenetriamine pentaacetic acid (AB-DTPA) extractable Fe in the soils. The increase of extractable Fe was usually proportional to the application rate, and enhanced by the acidification of slag. Steel slag appeared to be a promising and inexpensive source of Fe to alleviate crop Fe chlorosis in Fe-deficient calcareous soils.

  19. Reactions Between MgO-C Refractory, Molten Slag and Metal

    National Research Council Canada - National Science Library

    Li, Zushu; Mukai, Kusuhiro; Tao, Zainan

    2000-01-01

    The behavior of MgO-C refractory-slag-metal system, which is caused by the reactions such as the dissolution of MgO and graphite in the refractory into slag and metal respectively and the generation...

  20. 80 FR 75817 - NESHAP for Brick and Structural Clay Products Manufacturing; and NESHAP for Clay Ceramics...

    Science.gov (United States)

    2015-12-04

    ... NESHAP for Clay Ceramics Manufacturing: Correction AGENCY: Environmental Protection Agency (EPA). ACTION...; and NESHAP for Clay Ceramics Manufacturing. These amendments make two technical corrections to...

  1. Development of Glass Ceramics Made From Ferrous Tailings and Slag in China

    Institute of Scientific and Technical Information of China (English)

    LIU Cheng-jun; SHI Pei-yang; ZHANG Da-yong; JIANG Mao-fa

    2007-01-01

    A great amount of ferrous tailings and slag cause severe damage to the ecological environment, which must be reclaimed and utilized. The composition, type, and characteristics of ferrous tailings and slag in China were introduced. The research status and the application outlook of glass ceramics made from ferrous tailings and slag were discussed. Glass ceramics made from ferrous tailings and slag can be applied to various fields, and it will be environmentally conscious materials in the 21st century.

  2. 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

  3. Oxic limestone drains for treatment of dilute, acidic mine drainage

    Science.gov (United States)

    Cravotta, Charles A.

    1998-01-01

    Limestone treatment systems can be effective for remediation of acidic mine drainage (AMD) that contains moderate concentrations of dissolved O2 , Fe3+ , or A13+ (1‐5 mg‐L‐1 ). Samples of water and limestone were collected periodically for 1 year at inflow, outflow, and intermediate points within underground, oxic limestone drains (OLDs) in Pennsylvania to evaluate the transport of dissolved metals and the effect of pH and Fe‐ and Al‐hydrolysis products on the rate of limestone dissolution. The influent was acidic and relatively dilute (pH 1 mg‐L‐1 ) but was near neutral (pH = 6.2‐7.0); Fe and Al decreased to less than 5% of influent concentrations. As pH increased near the inflow, hydrous Fe and Al oxides precipitated in the OLDs. The hydrous oxides, nominally Fe(OH)3 and AI(OH)3, were visible as loosely bound, orange‐yellow coatings on limestone near the inflow. As time elapsed, Fe(OH)3 and AI(OH)3 particles were transported downflow. During the first 6 months of the experiment, Mn 2+ was transported conservatively through the OLDs; however, during the second 6 months, concentrations of Mn in effluent decreased by about 50% relative to influent. The accumulation of hydrous oxides and elevated pH (>5) in the downflow part of the OLDs promoted sorption and coprecipitation of Mn as indicated by its enrichment relative to Fe in hydrous‐oxide particles and coatings on limestone. Despite thick (~1 mm) hydrous‐oxide coatings on limestone near the inflow, CaCO3 dissolution was more rapid near the inflow than at downflow points within the OLD where the limestone was not coated. The rate of limestone dissolution decreased with increased residence time, pH, and concentrations of Ca2+ and HCO3‐ and decreased PCO2. The following overall reaction shows alkalinity as an ultimate product of the iron hydrolysis reaction in an OLD:Fe2+ + 0.25 O2 +CaCO3 + 2.5 H2O --> Fe(OH)3 + 2 Ca2+ + 2 HCO3-where 2 moles of CaCO3 dissolve for each mole of Fe(OH)3 produced

  4. Pyrometallurgical slags as a potential source of selected metals recovery

    Directory of Open Access Journals (Sweden)

    K. Nowińska

    2014-10-01

    Full Text Available Complex analysis of concentration and form of occurrence such metals as Zn, Pb, Fe and Cu in slags formed during a current zinc production in the Imperial Smelting Process (ISP is a possible basis for development of optimal recovery technology. For this purpose studies of slags from the current production of the Shaft Furnace Unit and of the Lead Refining of the “Miasteczko Śląskie” Zinc Smelting Plant were carried out. The studies results show that slags includes high concentrations of: Zn from 0,064 % to 1,680 %, Pb from 10,56 % to 50,71 %, Fe from 0,015 % to 2,576 %, Cu from 7,48 % to 64,95 %, and change in a broad range. This slags show significant heterogeneity, caused by intermetallic phases (Zn - Pb, Cu - Zn, Cu - Pb formed on the surface thereof. It is so possible that slag can be a potential source of this metals recovery.

  5. Preparation of calcium silicate absorbent from iron blast furnace slag.

    Science.gov (United States)

    Brodnax, L F; Rochelle, G T

    2000-09-01

    Calcium silicate hydrate (CSH) solids were prepared from hydrated lime and iron blast furnace slag in an aqueous agitated slurry at 92 degrees C. While it was hoped a minimal lime/slag ratio could be used to create near-amorphous CSH, the surface area of the product improved by increasing the lime/slag weight ratio to 2. The addition of gypsum to the lime/slag system dramatically improved the formation of surface area, creating solids with 139 m2/g after 30 hr of reaction when only a minimal amount of lime was present. The SO2 reactivity of solids prepared with gypsum greatly exceeded that of hydrated lime, achieving greater than 70-80% conversion of the alkalinity after 1 hr of reaction with SO2. The use of CaCl2 as an additive to the lime/slag system, in lieu of gypsum, also produced high-surface-area solids, 115 m2/g after 21 hr of reaction. However, the SO2 reactivity of these sorbents was relatively low given the high surface area. This emphasized that the correlation between surface area and SO2 reactivity was highly dependent on the solid phase, which was subsequently dependent on slurry composition.

  6. Nickel, copper and cobalt coalescence in copper cliff converter slag

    Directory of Open Access Journals (Sweden)

    Wolf A.

    2016-01-01

    Full Text Available The aim of this investigation is to assess the effect of various additives on coalescence of nickel, copper and cobalt from slags generated during nickel extraction. The analyzed fluxes were silica and lime while examined reductants were pig iron, ferrosilicon and copper-silicon compound. Slag was settled at the different holding temperatures for various times in conditions that simulated the industrial environment. The newly formed matte and slag were characterized by their chemical composition and morphology. Silica flux generated higher partition coefficients for nickel and copper than the addition of lime. Additives used as reducing agents had higher valuable metal recovery rates and corresponding partition coefficients than fluxes. Microstructural studies showed that slag formed after adding reductants consisted of primarily fayalite, with some minute traces of magnetite as the secondary phase. Addition of 5 wt% of pig iron, ferrosilicon and copper-silicon alloys favored the formation of a metallized matte which increased Cu, Ni and Co recoveries. Addition of copper-silicon alloys with low silicon content was efficient in copper recovery but coalescence of the other metals was low. Slag treated with the ferrosilicon facilitated the highest cobalt recovery while copper-silicon alloys with silicon content above 10 wt% resulted in high coalescence of nickel and copper, 87 % and 72 % respectively.

  7. Investigation of High-Temperature Slag/Copper/Spinel Interactions

    Science.gov (United States)

    De Wilde, Evelien; Bellemans, Inge; Campforts, Mieke; Guo, Muxing; Blanpain, Bart; Moelans, Nele; Verbeken, Kim

    2016-12-01

    An important cause for the mechanical entrainment of copper droplets in slags during primary and secondary copper production is their interaction with solid spinel particles, hindering the sedimentation of the copper droplets. In the present study, the interactions between the three phases involved (slag-Cu droplets-spinel solids) were investigated using an adapted sessile drop experiment, combined with detailed microstructural investigation of the interaction zone. An industrially relevant synthetic PbO-CaO-SiO2-Cu2O-Al2O3-FeO-ZnO slag system, a MgAl2O4 spinel particle, and pure copper were examined with electron microscopy after their brief interaction at 1523 K (1250 °C). Based on the experimental results, a mechanism depending on the interlinked dissolved Cu and oxygen contents within the slag is proposed to describe the origin of the phenomenon of sticking Cu alloy droplets. In addition, the oxygen potential gradient across the phases ( i.e., liquid Cu, slag, and spinel) appears to affect the Cu entrainment, as deduced from a microstructural analysis.

  8. Investigation of High-Temperature Slag/Copper/Spinel Interactions

    Science.gov (United States)

    De Wilde, Evelien; Bellemans, Inge; Campforts, Mieke; Guo, Muxing; Blanpain, Bart; Moelans, Nele; Verbeken, Kim

    2016-09-01

    An important cause for the mechanical entrainment of copper droplets in slags during primary and secondary copper production is their interaction with solid spinel particles, hindering the sedimentation of the copper droplets. In the present study, the interactions between the three phases involved (slag-Cu droplets-spinel solids) were investigated using an adapted sessile drop experiment, combined with detailed microstructural investigation of the interaction zone. An industrially relevant synthetic PbO-CaO-SiO2-Cu2O-Al2O3-FeO-ZnO slag system, a MgAl2O4 spinel particle, and pure copper were examined with electron microscopy after their brief interaction at 1523 K (1250 °C). Based on the experimental results, a mechanism depending on the interlinked dissolved Cu and oxygen contents within the slag is proposed to describe the origin of the phenomenon of sticking Cu alloy droplets. In addition, the oxygen potential gradient across the phases (i.e., liquid Cu, slag, and spinel) appears to affect the Cu entrainment, as deduced from a microstructural analysis.

  9. BUILDING MATERIALS AND PRODUCTS BASED ON SILICON MANGANESE SLAGS

    Directory of Open Access Journals (Sweden)

    BOLSHAKOV V. I.

    2016-05-01

    Full Text Available Raising of problem. Currently of particular relevance was given to the matter of introduction in manufacture of building materials and products, resource-saving techniques and technologies; integrated use of raw materials and materials that prevent or significantly reduce their harmful impact on the environment. This allows you to recycle hundreds of thousands of tons of the fiery liquid slags of silicon manganese and to develop effective structural materials that can replace metals, non-metallic building materials of natural origin, concretes, cast stone, plastics and refractories. Purpose. The study of the structure and properties of building materials and products from electric furnace slag of silicon manganese. Conclusion. Slags from the smelting of silicon manganese are classified as acidic. Their lime factor is in the range of 0.47–0.52. The composition of the slag located in the heterogeneous region SiO2 near the line of separation of cristobalite spread to the crystallization of wollastonite, according to the ternary system MnO-CaO-SiO2, which in consideration of their stability, allows the development of technology of building materials (gravel, sand, granulated slag, etc. and products (foundation blocks, road slabs, containers for transportation and storage of hazardous waste, and others.

  10. Boron enrichment in martian clay.

    Directory of Open Access Journals (Sweden)

    James D Stephenson

    Full Text Available We have detected a concentration of boron in martian clay far in excess of that in any previously reported extra-terrestrial object. This enrichment indicates that the chemistry necessary for the formation of ribose, a key component of RNA, could have existed on Mars since the formation of early clay deposits, contemporary to the emergence of life on Earth. Given the greater similarity of Earth and Mars early in their geological history, and the extensive disruption of Earth's earliest mineralogy by plate tectonics, we suggest that the conditions for prebiotic ribose synthesis may be better understood by further Mars exploration.

  11. Boron Enrichment in Martian Clay

    Science.gov (United States)

    Nagashima, Kazuhide; Freeland, Stephen J.

    2013-01-01

    We have detected a concentration of boron in martian clay far in excess of that in any previously reported extra-terrestrial object. This enrichment indicates that the chemistry necessary for the formation of ribose, a key component of RNA, could have existed on Mars since the formation of early clay deposits, contemporary to the emergence of life on Earth. Given the greater similarity of Earth and Mars early in their geological history, and the extensive disruption of Earth's earliest mineralogy by plate tectonics, we suggest that the conditions for prebiotic ribose synthesis may be better understood by further Mars exploration. PMID:23762242

  12. Strength Properties of Aalborg Clay

    DEFF Research Database (Denmark)

    Iversen, Kirsten Malte; Nielsen, Benjaminn Nordahl; Augustesen, Anders Hust

    resulted in many damaged buildings in Aalborg. To provide sufficient bearing capacity it is therefore necessary either to remove the fill or to construct the building on piles. Both methods imply that the strength of Aalborg Clay is important for the construction. This paper evaluates the strength...... of Aalborg Clay by use of triaxial tests from four different locations. Both the drained strength (c and ϕ) and the undrained strength (cu) are assessed through two different methods: one where the strength is assumed to vary with the effective stress and another where the strength is found to be constant....

  13. Preparation of Slag Wool by Integrated Waste-Heat Recovery and Resource Recycling of Molten Blast Furnace Slags: From Fundamental to Industrial Application

    Directory of Open Access Journals (Sweden)

    Dawei Zhao

    2014-05-01

    Full Text Available The present paper investigated the process of the slag wool fabrication using high temperature blast furnace (BF slag modified by coal ash (CA. The liquidus temperature and viscosity of the slag system with different mass ratios of BF slag and CA were measured through an inner cylinder rotation method. The approximate mass ratio used to fabricate the slag wool was therefore determined and slag wool was then successfully prepared with a high-speed air injection method in the laboratory. The effect of mBF/m ratio, slag temperature for injection and air pressure on the preparation of slag wool was systematically investigated. The mechanical and thermal properties were also studied to confirm the long-term working conditions of the slag wool. An industry-scale slag wool production application was established. The energy consumption and the pollutant generation, were analyzed and compared with the traditional production method, which indicated a 70% reduction in energy consumption and a 90% pollution emission decrease.

  14. Size-dependent enrichment of waste slag aggregate fragments abraded from asphalt concrete.

    Science.gov (United States)

    Takahashi, Fumitake; Shimaoka, Takayuki; Gardner, Kevin; Kida, Akiko

    2011-10-30

    Authors consider the environmental prospects of using melted waste slag as the aggregate for asphalt pavement. In particular, the enrichment of slag-derived fragments in fine abrasion dust particles originated from slag asphalt concrete and its size dependency were concerned. A series of surface abrasion tests for asphalt concrete specimens, containing only natural aggregates as reference or 30 wt% of substituted slag aggregates, were performed. Although two of three slag-asphalt concretes generated 1.5-3.0 times larger amount of abrasion dust than the reference asphalt concrete did, it could not be explained only by abrasion resistance of slag. The enrichment of slag-derived fragments in abrasion dust, estimated on the basis of the peak intensity of quartz and heavy metal concentrations, had size dependency for all slag-asphalt concretes. Slag-derived fragments were enriched in abrasion dust particles with diameters of 150-1000 μm. Enrichment factors were 1.4-2.1. In contrast, there was no enrichment in abrasion dust particles with diameter less than 75 μm. This suggests that prior airborne-size fragmentation of substituted slag aggregates does not need to be considered for tested slag aggregates when environmental risks of abrasion dust of slag-asphalt pavement are assessed.

  15. Effects of slag and fly ash in concrete in chloride environment

    NARCIS (Netherlands)

    Polder, R.B.

    2012-01-01

    This paper addresses experience from The Netherlands with blast furnace slag and fly ash in concrete in chloride contaminated environments, both from the field and the laboratory. Use of slag produced in The Netherlands started in the 1930s and CEM III/B LH HS, with typically 70% slag, became the do

  16. Clay membrane made of natural high plasticity clay

    DEFF Research Database (Denmark)

    Foged, Niels; Baumann, Jens

    1998-01-01

    Leachate containment in Denmark has through years been regulated by the DIF Recommendation for Sanitary Landfill Liners (DS/R 466). It states natural clay deposits may be used for membrane material provided the membrane and drainage system may contain at least 95% of all leachate created throughout...

  17. Limestone in converter steelmaking practice%石灰石在转炉炼钢中的应用实践

    Institute of Scientific and Technical Information of China (English)

    魏宝森

    2012-01-01

    分析了石灰石加入转炉后热分解反应过程中的能量消耗和特性以及分解过程中的渣化反应.阐述了石灰石应用于转炉炼钢的优越性,既可以部分替代石灰减少对石灰的消耗,同时还可以平衡转炉富裕热量,减少其他降温料的使用量,为炼钢生产节约了成本,创造了更大利润空间.%The energy consumption and characteristics of the process of thermal decomposition reaction were analyzed when the limestone added to the converter slag reaction and the decomposition process. Described the superiority of the limestone used in the converter steelmaking. Not only a partial substitute for lime to reduce the consumption of lime, but also could be balanced converter wealthy beat, reduce the use of other cooling material for the steel production cost savings to create a greater interest of space.

  18. A Resource Inventory of Selected Outcrops Along the White Clay Fault in Southwestern South Dakota

    Science.gov (United States)

    Sanovia, L.

    2012-12-01

    The White Clay Fault, located in southwestern South Dakota, formed after the Laramide orogeny (65mya) that resulted in the uplift of the Black Hills in western South Dakota and eastern Wyoming. Many of the outcrops along the White Clay Fault are part of the Eocene-Oligocene White River Group (37-26.9 mya), an accumulation of nonmarine sediments composed primarily of tuffaceous mudstones and silty claytones with lesser amounts of kaolinitic sandstones, lacustrine limestones and gypsum. (LaGarry, 1998; LaGarry and LaGarry, 1997). White River Group sediments also consist of volcanic ash from eruptions in the southwestern United States (Larson and Evanoff, 1998). The White Clay Fault lies at the outer boundary of the Black Hills uplift. After the fault formed, the eventual erosion of overlying White River Group materials exposed outcrops of Late Cretaceous Niobrara chalk that formed between 145.5-65.5 mya, at a time when this region was covered by the Western Interior Seaway. The Niobrara Formation consists of chalk and limestone interbedded with marls and shale (Locklear and Sageman, 2008). This poster records a geological and paleontological resource inventory for two selected outcrops that are within a short walking distance of each other along the White Clay Fault. Outcrops on the downside of the fault belongs to the Peanut Peak member of the White River Group, while the outcrops on the upside of the fault belong to the Niobrara Formation; a difference of 60 million years. The selected outcrops are on sensitive land on the Pine Ridge Indian Reservation that has never been inventories before due to sovereignty issues. As such, this resource inventory represents one of many initial steps being taken by students and faculty at Oglala Lakota College to determine the geological resources of the Reservation.

  19. The Kinetics of Calcination of High Calcium Limestone

    Directory of Open Access Journals (Sweden)

    P. C. Okonkwo

    2012-02-01

    Full Text Available The kinetics of calcination of a high calcium type of limestone was studied. Ukpilla limestone found in the central region of Nigeria was studied. The limestone composition shows that the limestone has 51.29% calcium oxide and 41.53% loss on ignition and magnesium oxide content of 2.23%. The following parameters were determined; diffusion coefficient of lime layer, and mass transfer coefficient, conductivity of lime layer and beat transfer coefficient, convective parameter and diffusive parameter for temperatures 9000C, 10000C, 10600C and 10800C. The reaction was found to be limited by mass and heat transfers across the tune layer of the calcining article, theoptimal temperature of calcination was found to be 10600C. Diffusivity and mass transfer coefficient decreases with increase in calcination temperature. The thermal conductivity increases with increase in temperature. The diffusive and convective parameter decreases with increase in temperature. The reactivity of lime calcined at different temperatures were determined. The reactivity of the lime increases with decrease in calcination temperature.

  20. Shear creep characteristics and constitutive model of limestone

    Institute of Scientific and Technical Information of China (English)

    Yu Mei; Mao Xianbiao; Hu Xinyu

    2016-01-01

    The characters of limestone in weak interlayer of a high rocky slope in Xuzhou, China, are studied by shear static test and shear creep test. The results show that limestone specimens have attenuation creep properties and constant rate creep properties, almost have no accelerated creep properties. The exponen-tial type empirical formula is selected to fit creep grading curves by polynomial regression analysis method, and the square sums of the fitting results residual are in the order of 10-7. Then grade creep curves at every shear loads are set up. Combining creep rate-time curve, the creep properties of limestone are analyzed. As the physical meaning of component model is clearer, the Poytin–Thomson model is set up. Through the least square method, the optimal parameters of Poytin–Thomson model are obtained, and the sums of squared residuals belong to 10-3 order of magnitude, which can meet the accuracy requirements of engineering calculation. So the Poytin–Thomson model can reflect the shear creep char-acteristics of limestone very well.

  1. Catalytic and Gas-Solid Reactions Involving HCN over Limestone

    DEFF Research Database (Denmark)

    Jensen, Anker; Johnsson, Jan Erik; Dam-Johansen, Kim

    1997-01-01

    In coal-fired combustion systems solid calcium species may be present as ash components or limestone added to the combustion chamber. In this study heterogeneous reactions involving HCN over seven different limestones were investigated in a laboratory fixed-bed quartz reactor at 873-1,173 K....... Calcined limestone is an effective catalyst for oxidation of HCN. Under conditions with complete conversion of HCN at O-2 concentrations above about 5,000 ppmv the selectivity for formation of NO and N2O is 50-70% and below 5%, respectively. Nitric oxide can be reduced by HCN to N-2 in the absence of O-2...... and to N-2 and N2O in the presence of O-2. At low O-2 concentrations or low temperatures. HCN may react with CaO, forming calcium cyanamide, CaCN2. The selectivities for formation of NO and N2O from oxidation of CaCN2 is 20-25% for both species. The catalytic activity of limestone for oxidation of HCN...

  2. The Solnhofen Limestone: A stony heritage of many uses

    Science.gov (United States)

    Kölbl-Ebert, Martina; Kramar, Sabina; Cooper, Barry J.

    2016-04-01

    High above the valley of the River Altmühl (Bavaria, Germany), between Solnhofen to the west and Kelheim to the east, numerous quarries give access to thinly plated limestone from the Upper Jurassic, some 150 million years before the present. The main quarry areas lie around the town of Eichstätt and between the villages of Solnhofen, Langenaltheim and Mörnsheim. Here limestone slabs have been quarried for several hundred years, some even in Roman times. Solnhofen Limestone is famous worldwide; not only because it is a beautiful building stone of high quality, but also because of the exceptionally well-preserved fossils it contains -among them the early bird Archaeopteryx. The quarry industry between Solnhofen and Eichstätt has shaped a cultural landscape, with old and new quarries sunk into the plain and numerous spoil heaps rising above it, for the rock is not all economically useful. But many of the spoil heaps and the old quarries are environmentally protected as they provide a habitat for some rare plants and animals. It is not necessary to cut the Solnhofen Limestone with a saw: it is split by hand into thin and even slabs or sheets which are used for flagstones and wall covers, which since centuries are sold world-wide. Locally it also serves as roof tiles for traditional houses. Thick slabs of especially fine quality may be found near Solnhofen and Mörnsheim and are used for lithography printing.

  3. Fine-scale species associations in alvar limestone grasslands

    NARCIS (Netherlands)

    Diekmann, M; Dupre, C; van der Maarel, E

    2004-01-01

    To examine the importance of positive or negative interactions of plant species on a micro-scale, species associations were studied in 38 1 m(2) - plots in alvar limestone grasslands on Oland, Sweden. Each plot was assumed to be homogeneous as to its environmental conditions and spatial distribution

  4. 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.

  5. Structure and Vibrational Spectra of Slags Produced from Radioactive Waste

    Science.gov (United States)

    Malinina, G. A.; Stefanovsky, S. V.

    2014-05-01

    The structure of the anionic motif of aluminosilicate and aluminoborosilicate glasses containing simulated slags from a solid radioactive waste incinerator was studied by IR and Raman spectroscopy. Spectra of melted slag were consistent with Si-O tetrahedra with various numbers of bridging O ions and Al-O tetrahedra embedded in the Si-O network in the slag vitreous and crystalline phases (nepheline, nagelschmidtite). Vibrations of doubly and triply bound Si-O tetrahedra and Al-O tetrahedra embedded between them were mainly responsible for the spectra as the content of sodium disilicate fl ux and the glass fraction in the materials increased. Addition of sodium tetraborate fl ux caused the appearance of B-O vibrations of predominantly three-coordinate B and a tendency toward chemical differentiation preceding phase separation.

  6. Vanadium removal from LD converter slag using bacteria and fungi.

    Science.gov (United States)

    Mirazimi, S M J; Abbasalipour, Z; Rashchi, F

    2015-04-15

    Removal of vanadium from Linz-Donawits (LD) converter slag was investigated by means of three different species of microbial systems: Acidithiobacillus thiooxidans (autotrophic bacteria), Pseudomonas putida (heterotrophic bacteria) and Aspergillus niger (fungi). The bioleaching process was carried out in both one-step and two-step process and the leaching efficiencies in both cases were compared. Formation of inorganic and organic acids during the leaching process caused mobilization of vanadium. In order to reduce toxic effects of the metal species on the above mentioned microorganisms, a prolonged adaptation process was performed. Both bacteria, A. thiooxidans and P. putida were able to remove more than 90% of vanadium at slag concentrations of 1-5 g L(-1) after 15 days. Also, the maximum achievable vanadium removal in the fungal system was approximately 92% at a slag concentration of 1 g L(-1) after 22 days.

  7. Effects of slag fineness on durability of mortars

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In recent years, the usages of by-products and wastes in industry have become more important. The importance of the sustainable development is also of increasing. The utilizations of wastes, as mineral admixture or fine aggregate, reduce the consumption of the natural resources and improve the durability of concrete. In this study, the effect of the fineness on the high temperature and sulphate resistances of concrete mortar specimens, produced with ground granulated blast-furnace slag (GBFS)replacing cement, is investigated. The compressive and flexural strength test results for all series related to durability effects,exposing temperature and solutions, exposure times for these durability effects, slag content and fineness are discussed. Consequently, the optimum slag contents are determined for producing the sulphate and high temperature resistant mortars.

  8. Pyrochemical recovery of plutonium from calcium fluoride reduction slag

    Science.gov (United States)

    Christensen, D.C.

    A pyrochemical method of recovering finely dispersed plutonium metal from calcium fluoride reduction slag is claimed. The plutonium-bearing slag is crushed and melted in the presence of at least an equimolar amount of calcium chloride and a few percent metallic calcium. The calcium chloride reduces the melting point and thereby decreases the viscosity of the molten mixture. The calcium reduces any oxidized plutonium in the mixture and also causes the dispersed plutonium metal to coalesce and settle out as a separate metallic phase at the bottom of the reaction vessel. Upon cooling the mixture to room temperature, the solid plutonium can be cleanly separated from the overlying solid slag, with an average recovery yield on the order of 96 percent.

  9. Holocene limestones of part of the western continental shelf of India

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, R.R.; Hashimi, N.H.; Guptha, M.V.S.

    Dredging on the western continental shelf of India has shown that the most common rock types outcropping on the irregular topography of the outer shelf (70-90 m) are algal limestones and shelly limestones containing superficial ooids and pelletoids...

  10. Overlying surficial deposits and absent areas for the Madison Limestone, Black Hills area, South Dakota.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set describes areas where the Madison Limestone is directly overlain by surficial deposits, as well as those areas where the Madison Limestone is absent...

  11. Overlying surficial deposits and absent areas for Minnekahta Limestone in the Black Hills area, South Dakota

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set describes areas where the Minnekahta Limestone is directly overlain by surficial deposits, as well as those areas where the Minnekahta Limestone is...

  12. Picasso Masks: Cubism in Clay

    Science.gov (United States)

    Daddino, Michelle

    2010-01-01

    This article describes an art project developed by the author which provides a way to further the children's understanding of Picasso's Cubism style in 3-D. Through this project, upper-elementary students learn a bit about the life and art of Picasso as they gain a firm understanding of the style of art known as Cubism, and apply clay techniques…

  13. ADSORPTION OF SURFACTANT ON CLAYS

    Science.gov (United States)

    Surfactants used to enhance remediation of soils by soil washing are often lost in the process. Neither the amount nor the cause of this loss is known. It is assumed that clays present in the soil are responsible for the loss of the surfactant. In this papere, adsorption prope...

  14. Biodegradable Pectin/clay Aerogels

    Science.gov (United States)

    Biodegradable, foamlike materials based on renewable pectin and sodium montmorillonite clay were fabricated through a simple, environmentally friendly freeze-drying process. Addition of multivalent cations (Ca2+ and Al3+) resulted in apparent crosslinking of the polymer, and enhancement of aerogel p...

  15. Geotechnical properties of Karwar marine clay

    Digital Repository Service at National Institute of Oceanography (India)

    Bhat, S.T.; Nayak, B.U.; Naik, R.L.

    Karwar marine clay possesses high plasticity characteristics with natural water content higher than the liquid limit. Liquidity index was as high as 1.7. Predominant clay mineral was kaolinite. Undrained shear strength showed an increasing trend...

  16. Synthesis and Characteristics of Anorthite Ceramics from Steelmaking Slag

    Science.gov (United States)

    Li, Bowen; He, Mingsheng; Hwang, Jiann-Yang; Gan, Wangui

    Steelmaking slag is an alkaline solid waste consisting mainly oxides of calcium, iron, silicon, magnesium, and aluminum. Its large quantity and chemical property makes it challenging for recycling the material in various industrial applications. In this study, hot-poured steelmaking slag was used to prepare ceramics. After mixing with kaolin and quartz, ceramic products were synthesized via sintering. The appropriate sintering temperature is 1200°C. XRD analysis showed the major mineral phases were anorthite and pyroxene. SEM images showed that the new crystal particles were uniformly formed and distributed. Reaction mechanisms were discussed.

  17. Modeling the service life of slag concrete exposed to chlorides

    Directory of Open Access Journals (Sweden)

    O.A. Hodhod

    2014-03-01

    A partial replacement of OPC with 50% WCS in OPC paste mixes resulted in an increase in the amount of calcium silicate hydrate (CSH by 57%, a decrease in the amount of calcium hydroxide (CH by 66%, and a decrease in the amount of capillary pores by 57%, compared to those in the pure OPC matrix. In addition, the research results demonstrate that increasing Cs from 1% to 5% resulted in dramatically decreasing the service life of OPC/slag concrete, where the amount of decreasing reaches about 71%. Also, the service life of concrete increases with increasing slag content.

  18. CFD Modelling and Experimental Testing of Thermal Calcination of Kaolinite Rich Clay Particles - An Effort towards Green Concrete

    DEFF Research Database (Denmark)

    Gebremariam, Abraham Teklay

    Cement industry is one of the major industrial emitters of greenhouse gases, generating 5-7% of the total anthropogenic CO2 emissions. Consequently, use of supplementary cementitious materials (SCM) to replace part of the CO2-intensive cement clinker is an attractive way to mitigate CO2 emissions...... from cement industry. SCMs based on industrial byproducts like fly ashes and slags are subject to availability problems. Yet clays are the most ubiquitous material on earth's crust. Thus, properly calcined clays are a very promising candidate for SCMs to produce green cements. Calcination...... PROcess Modeling System) software, which is suspended during the project due to the adjustment made by the project consortium. The model results from both C++ and gPROMS software show good similarity. Various experiments have been performed to derive key kinetic data, to collect data from a gas suspension...

  19. 21 CFR 186.1256 - Clay (kaolin).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Clay (kaolin). 186.1256 Section 186.1256 Food and... Substances Affirmed as GRAS § 186.1256 Clay (kaolin). (a) Clay (kaolin) Al2O3.2SiO2.nH2O, Cas Reg. No. 1332-58-7) consists of hydrated aluminum silicate. The commercial products of clay (kaolin) contain...

  20. 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.

  1. Characterization of ancient Indian iron and entrapped slag inclusions using electron, photon and nuclear microprobes

    Indian Academy of Sciences (India)

    P Dillmann; R Balasubramaniam

    2001-06-01

    Compositional and structural information were obtained from an ancient 1600-year old Indian iron using microprobe techniques (EDS, XRD and PIXE). Several different local locations in the iron matrix and in the entrapped slag inclusions were analyzed. The P content of the metallic iron matrix was very heterogeneous. Lower P contents were observed in the regions near slag inclusions. This was correlated to the dephosphorization capacity of the slag. The crystallized phases identified in the slag inclusions were wüstite and fayalite. The compositions of the slag inclusions were relatively homogeneous.

  2. Future Resources for Eco-building Materials: I.Metallurgical Slag

    Institute of Scientific and Technical Information of China (English)

    XU Delong; LI Hui

    2009-01-01

    In order to make an effectivily recycle use of iron and steel slags that are main industrial wastes generated in Chinese metallurgical industry,the current technologies for reprocessing and recycling these wastes into eco-building materials were reviewed,such as preparing cement-steel slag blended cement with steel slag after metal recovery,using the fine powder of blast furnace slag (BFS)for manufacturing slag cement and high performance concrete.A further research on using these available resources more efficiently were discussed.

  3. 76 FR 60815 - Final Legislative Environmental Impact Statement (LEIS) for the Limestone Hills Training Area...

    Science.gov (United States)

    2011-09-30

    ... Department of the Army Final Legislative Environmental Impact Statement (LEIS) for the Limestone Hills... land within the Limestone Hills Training Area (LHTA) from BLM administration. The LEIS proposes that..., mining, recreation, transportation, utility right-of-ways, and wildlife management. A limestone mine...

  4. Quarry Quest. A Field Trip Guide to the Indiana Limestone District, Monroe and Lawrence Counties, Indiana.

    Science.gov (United States)

    Shewmaker, Sherman N.

    This guide provides information for planning a field trip to the Indiana Limestone District. This district, located in Monroe and Lawrence Counties, Indiana, is responsible for material that has dominated the building-limestone market in the United States for nearly a century. A few of the many well-known buildings using Indiana limestone are the…

  5. Clay Cuffman: A Cool, Calm, Relaxed Guy

    Science.gov (United States)

    Booth, Gina

    2010-01-01

    This article describes Clay Cuffman, a simple clay-sculpture project that requires two or three sessions, and works for students from the upper-elementary level through high school. It takes about 1.5 pounds of clay per student--about the size of a small grapefruit. The Cuffman project is a great way for upper-elementary through high-school…

  6. Hydrodynamic erosion process of undisturbed clay

    NARCIS (Netherlands)

    Zhao, G.; Visser, P.J.; Vrijling, J.K.

    2011-01-01

    This paper describes the hydrodynamic erosion process of undisturbed clay due to the turbulent flow, based on theoretical analysis and experimental results. The undisturbed clay has the unique and complicated characteristics of cohesive force among clay particles, which are highly different from dis

  7. Clay & Children: More than Making Pots.

    Science.gov (United States)

    Kolbe, Ursula

    1997-01-01

    Working with clay enables young children to express, explore, and communicate their feelings and ideas. This resource booklet for early childhood practitioners and it promotes the clay table as a special place for shared discoveries, social interaction, and discussion. The booklet provides a glossary of terms used in clay work, as well as reasons…

  8. The systems containing clays and clay minerals from modified drug release: a review.

    Science.gov (United States)

    Rodrigues, Luís Alberto de Sousa; Figueiras, Ana; Veiga, Francisco; de Freitas, Rivelilson Mendes; Nunes, Lívio César Cunha; da Silva Filho, Edson Cavalcanti; da Silva Leite, Cleide Maria

    2013-03-01

    Clays are materials commonly used in the pharmaceutical industry, either as ingredients or as active ingredients. It was observed that when they are administered concurrently, they may interact with drugs reducing their absorption. Therefore, such interactions can be used to achieve technological and biopharmaceutical advantages, regarding the control of release. This review summarizes bibliographic (articles) and technological (patents) information on the use of systems containing clays and clay minerals in modified drug delivery. In this area, formulations such natural clay, commercial clay, synthetic clay, composites clay-polymers, nanocomposites clay-polymers, films and hidrogels composites clay-polymers are used to slow/extend or vectorize the release of drugs and consequently they increase their bioavailability. Finally, this review summarizes the fields of technology and biopharmaceutical applications, where clays are applied.

  9. In situ observation of the role of alumina particles on the crystallization behavior of slags

    Energy Technology Data Exchange (ETDEWEB)

    Orrling, C.

    2000-09-01

    The confocal laser scanning microscope (CLSM) allows crystallization behavior in liquid slags to he observed in situ at high temperatures. Slags in the lime-silica-alumina-magnesia system are easily tinder cooled and it is possible to construct time temperature transformation (TTT) diagrams for this system. The presence of solid alumina particles its these liquid slags was studied to determine if these particles act as heterogeneous nucleation sites that cause she precipitation of solid material within slags. The introduction of alumina particles reduced the incubation time for the onset of crystallization and increased the temperature at which crystallization was observed in the slags to close to the liquidus temperature for the slag. Crystal growth rates are in a good agreement with Ivantsov's solution of the problem of diffusion controlled dendritic growth. Alumina appears to be a potent nucleating agent in the slag systems that were studied. (author)

  10. Replacement of Natural Fine Aggregate With Air Cooled Blast Furnace Slag An Industrial By Product

    Directory of Open Access Journals (Sweden)

    Dr. B. Krishna Rao

    2015-07-01

    Full Text Available The aim of the investigation is to replace natural fine aggregatewith Air Cooled Blast Furnace Slag in OPC concrete. At present, nearly million tons of slag is being produced in the steel plants, in India. The generation of slag would be dual problem in disposal difficulty and environmental pollution. Some strategies should be used to utilize the slag effectively. Considering physical properties of metallurgical slags and a series of possibilities for their use in the field of civil constructions, this report demonstrates the possibilities of using air cooled blast furnace slag as partial replacement of sand in concrete. A total of five concrete mixes, containing 0%, 12.5%, 25%, 37.5% and 50% partial replacement of regular sand with air cooled blast furnace slag are investigated in the laboratory. These mixes were tested to determine axial compressive strength, split tensile strength, and flexural strength for 7days, 28days, 56days and 90days.

  11. Waste activated sludge hydrolysis and acidification: A comparison between sodium hydroxide and steel slag addition.

    Science.gov (United States)

    Zhang, Ying; Zhang, Chaojie; Zhang, Xuan; Feng, Leiyu; Li, Yongmei; Zhou, Qi

    2016-10-01

    Alkaline treatment with steel slag and NaOH addition were investigated under different pH conditions for the fermentation of waste activated sludge. Better performance was achieved in steel slag addition scenarios for both sludge hydrolysis and acidification. More solubilization of organic matters and much production of higher VFA (volatile fatty acid) in a shorter time can be achieved at pH10 when adjusted by steel slag. Higher enzyme activities were also observed in steel slag addition scenarios under the same pH conditions. Phosphorus concentration in the supernatant increased with fermentation time and pH in NaOH addition scenarios, while in contrast most phosphorus was released and captured by steel slag simultaneously in steel slag addition scenarios. These results suggest that steel slag can be used as a substitute for NaOH in sludge alkaline treatment.

  12. Petrochemistry of coal ash slags. I. Formation of melilite and a high temperature glass from a calcium-rich, silica-deficient slag

    Energy Technology Data Exchange (ETDEWEB)

    Schobert, H.H.; Barbie, D.L.; Christensen, O.D.; Kerner, F.R.

    1977-01-01

    Pilot plant studies are being conducted of a fixed-bed slagging coal gasification process. Lignite from the Indianhead mine is reacted with steam and oxygen in a gasifier at hearth zone temperatures over 1650/sup 0/C. Slag samples were subjected to chemical and petrographic analysis. Layers of layered slag modules were analyzed; the inner layers contain abundant melilite while the outer core is a glass. Results show that the characteristics of the coal ash slag can be affected by temperature fluctuations in the gasifier hearth, and that chemical, flow, and heat transfer behavior are all susceptible to change as a result. 8 figs., 3 tables. (DLC)

  13. 磷渣在生产油井水泥中的应用研究%Application of Phosphorus Slag in the Production of Oil Well Cement

    Institute of Scientific and Technical Information of China (English)

    邹兴芳; 朱教群; 陆小黑; 周卫兵

    2016-01-01

    在快硬早强硅酸盐油井水泥生料中掺入1%~3%磷渣作原料,代替部分石灰石、页岩配料,磷渣的掺入能显著降低烧成温度、减少熟料烧成热耗,改善熟料矿物形成条件和熟料矿物结构。由该熟料生产的油井水泥的早期强度能得到大幅提高,其它相关物理性能优异。%In order to fabricate fast hardening and early strength Portland cement,1%~3% phosphorus slag as raw material which was added into raw mineral as mixture to replace part of the limestone,shale ingredients.Addition of phosphorus slag can significantly reduce sintering temperature and the clinker burning heat consumption,and improve the clinker mineral formation conditions and clinker mineral structure.The early strength of cement produced by the clinker can be greatly improved,and other physical properties are also excellent.

  14. Mineral acquisition from clay by budongo forest chimpanzees

    NARCIS (Netherlands)

    Reynolds, Vernon; Lloyd, Andrew W.; English, Christopher J.; Lyons, Peter; Dodd, Howard; Hobaiter, Catherine; Newton-Fisher, Nicholas; Mullins, Caroline; Lamon, Noemie; Schel, Anne Marijke; Fallon, Brittany

    2015-01-01

    Chimpanzees of the Sonso community, Budongo Forest, Uganda were observed eating clay and drinking clay-water from waterholes. We show that clay, clay-rich water, and clay obtained with leaf sponges, provide a range of minerals in different concentrations. The presence of aluminium in the clay consum

  15. Aplicação superficial de calcário e diferentes resíduos em soja cultivada no sistema plantio direto Surface application of limestone and different residues on soybean grown in no-till system

    Directory of Open Access Journals (Sweden)

    Juliano Corulli Corrêa

    2009-01-01

    Full Text Available A prática da correção da acidez do solo pela aplicação superficial de corretivos sobre a palha no sistema plantio direto se restringe ao calcário, não havendo maiores estudos em relação à escória de aciaria, lama cal e lodo de esgoto centrifugado. O objetivo do trabalho foi avaliar os índices de acidez do solo e a produtividade da soja em função da aplicação superficial de lodo de esgoto centrifugado, lama cal, escória de aciaria e calcário dolomítico. O trabalho foi desenvolvido em Latossolo Vermelho distrófico, durante os anos agrícolas de 2002 a 2005, sob sistema plantio direto. Os tratamentos constituíram da aplicação superficial de escória de aciaria (E, lama cal (Lcal, lodo de esgoto centrifugado (LC, calcário dolomítico e sem aplicação de corretivo, em delineamento em blocos ao acaso, com quatro repetições. A aplicação superficial de escória de aciaria, lama cal e lodo de esgoto centrifugado permite a correção da acidez do solo, o deslocamento do Ca2+, o aumento da saturação por bases e redução do Al3+ até 40 cm, e para o calcário, até 20 cm, fatores que condicionaram o aumento da produtividade da soja para os tratamentos LC, E e Lcal em 2003/2004 e 2004/2005 e para LC e E em 2002/2003 no sistema plantio direto.The practice of correcting soil acidity by surface application of pH-correcting materials on crop residues in the no-till system is restricted to limestone. No further studies are available on the use of steel slag, lime mud, and centrifuged sewage sludge. The objective of this study was to evaluate soil acidity and yield of soybean as a function of surface application of centrifuged sewage sludge, lime mud, steel slag, and dolomitic limestone. The study was conducted on a dystrophic Clayey Rhodic Hapludox soil, during the 2002_2005 cropping seasons, under notill system. Treatments consisted on surface application of slag _ E, lime mud _ Lcal, centrifuged sewage sludge _ LC, dolomitic

  16. The Influence of Grain Size on Decomposition Reaction of Limestone in Dispersing State

    Institute of Scientific and Technical Information of China (English)

    XU De-long; WEI Hon-gen; LUO Yong-qin

    2004-01-01

    The thermal behavior and kinetic parameters of decomposition reaction of limestone in a temperature-programmed mode were investigated by means of TG. The experimental results show that the kinetic model functions in different forms for the thermal decomposition reactions of different limestone grain sizes in dispersing state under the atmosphere of static air are 4(1-α)3/4 for small size limestone and (1-α) for large size limestone. Information was obtained on the relationship among the decomposition temperature, decomposition time, decomposition fraction, decomposition reaction rate constant and grain size of limestone.

  17. Dephosphorization of Steelmaking Slag by Leaching with Acidic Aqueous Solution

    Science.gov (United States)

    Qiao, Yong; Diao, Jiang; Liu, Xuan; Li, Xiaosa; Zhang, Tao; Xie, Bing

    2016-09-01

    In the present paper, dephosphorization of steelmaking slag by leaching with acidic aqueous solution composed of citric acid, sodium hydroxide, hydrochloric acid and ion-exchanged water was investigated. The buffer solution of C6H8O7-NaOH-HCl system prevented changes in the pH values. Kinetic parameters including leaching temperature, slag particle size and pH values of the solution were optimized. The results showed that temperature has no obvious effect on the dissolution ratio of phosphorus. However, it has a significant effect on the dissolution ratio of iron. The dephosphorization rate increases with the decrease of slag particle size and the pH value of the solution. Over 90% of the phosphorus can be dissolved in the solution while the corresponding leaching ratio of iron was only 30% below the optimal condition. Leaching kinetics of dephosphorization follow the unreacted shrinking core model with a rate controlled step by the solid diffusion layer, the corresponding apparent activation energy being 1.233 kJ mol-1. A semiempirical kinetic equation was established. After leaching, most of the nC2S-C3P solid solution in the steelmaking slag was selectively dissolved in the aqueous solution and the iron content in the solid residue was correspondingly enriched.

  18. Aluminium salt slag characterization and utilization--a review.

    Science.gov (United States)

    Tsakiridis, P E

    2012-05-30

    Aluminium salt slag (also known as aluminium salt cake), which is produced by the secondary aluminium industry, is formed during aluminium scrap/dross melting and contains 15-30% aluminium oxide, 30-55% sodium chloride, 15-30% potassium chloride, 5-7% metallic aluminium and impurities (carbides, nitrides, sulphides and phosphides). Depending on the raw mix the amount of salt slag produced per tonne of secondary aluminium ranges from 200 to 500 kg. As salt slag has been classified as toxic and hazardous waste, it should be managed in compliance with the current legislation. Its landfill disposal is forbidden in most of the European countries and it should be recycled and processed in a proper way by taking the environmental impact into consideration. This paper presents a review of the aluminium salt slag chemical and mineralogical characteristics, as well as various processes for metal recovery, recycling of sodium and potassium chlorides content back to the smelting process and preparation of value added products from the final non metallic residue.

  19. ECOLOGICAL AND TECHNOLOGYCAL ASPECTS OF ASH AND SLAG WASTES UTILIZATION

    Directory of Open Access Journals (Sweden)

    Tatyana Aleksandrova

    2017-07-01

    Full Text Available The article presents the results of investigation focused on the utilization of ash and slag wastes (ASW in Russia including investigation of chemical and physical properties of ASW and processing products. Many factors influence the technological properties of ash and slag materials: naturals, processes and environments. The integrated treatment of ash and slag wastes of both stored and re-formed types will allow obtaining the following commercial products: coal concentrate, iron concentrate, aluminosilicate cenospheres, aluminosilicate product. In this study we have analyzed the methods for separation of ASW iron-containing part using the different types of the magnetic separation from the ash and slag material from one of the combined heat and power plant (CHPP in the Russian Far East Federal District. The greatest interest is the dry magnetic separation with travelling electromagnetic field. The subject of research was a sample taken from one of ash dump of CHPP in the Far East. In the study iron concentrate containing Fetotal = 64% was obtained recovery 68% in the low intensity (up to 5 kOe travelling magnetic field.

  20. The Interfacial Transition Zone in Alkali-Activated Slag Mortars

    Directory of Open Access Journals (Sweden)

    Rackel eSan Nicolas

    2015-12-01

    Full Text Available The interfacial transition zone (ITZ is known to strongly influence the mechanical and transport properties of mortars and concretes. This paper studies the ITZ between siliceous (quartz aggregates and alkali activated slag binders in the context of mortar specimens. Backscattered electron images (BSE generated in an environmental scanning electron microscope (ESEM are used to identify unreacted binder components, reaction products and porosity in the zone surrounding aggregate particles, by composition and density contrast. X-ray mapping is used to exclude the regions corresponding to the aggregates from the BSE image of the ITZ, thus enabling analysis of only the binder phases, which are segmented into binary images by grey level discrimination. A distinct yet dense ITZ region is present in the alkali-activated slag mortars, containing a reduced content of unreacted slag particles compared to the bulk binder. The elemental analysis of this region shows that it contains a (C,N-A-S-H gel which seems to have a higher content of Na (potentially deposited through desiccation of the pore solution and a lower content of Ca than the bulk inner and outer products forming in the main binding region. These differences are potentially important in terms of long-term concrete performance, as the absence of a highly porous interfacial transition zone region is expected to provide a positive influence on the mechanical and transport properties of alkali-activated slag concretes.

  1. Micronutrient availability from steel slag amendment in peatmoss substrates

    Science.gov (United States)

    The objective of this research was to determine the suitability of a steel slag product for supplying micronutrients to container-grown floriculture crops. Geranium (Pelargonium xhortorum 'Maverick Red') and tomato (Solanum lycopersicon 'Megabite') were grown in 11.4 cm containers with a substrate ...

  2. Slagging in a pulverised-coal-fired boiler

    Energy Technology Data Exchange (ETDEWEB)

    Devir, G.P.; Pohl, J.H.; Creelman, R.A. [University of Queensland, St. Lucia, Qld. (Australia). Dept. of Chemical Engineering

    2000-07-01

    This paper describes a technique to evaluate the severity of slagging of a coal in a pulverised-coal-fired boiler. There are few data in the literature on the nature of in-situ boiler slags, their rate of growth and/or their strength properties relevant to sootblowing. The latter is thought to be of more concern to boiler operators and gives rise to the significance of selecting suitable strength tests. As well as standardised methods for characterising pulverised coal performance in a boiler, several novel and less popular techniques are discussed in detail. A suite of three sub-bituminous coals from the Callide Coalfields, Biloela (600 km north of Brisbane), has been selected for slagging tests in the 350 MW{sub e} units of Callide 'B' power station. Disposable air-cooled mild steel slagging probes have been constructed to simulate the conditions for deposit formation in the boiler region. To date, tests for one of these coals has been completed and preliminary results are presented. Once testing for the remaining coals has been completed, it is anticipated that the differences exhibited in deposit growth and strength may be correlated with typical variations in physical and chemical properties of the pulverised coal.

  3. Contact micromechanics in granular media with clay

    Energy Technology Data Exchange (ETDEWEB)

    Ita, Stacey Leigh [Univ. of California, Berkeley, CA (United States)

    1994-08-01

    Many granular materials, including sedimentary rocks and soils, contain clay particles in the pores, grain contacts, or matrix. The amount and location of the clays and fluids can influence the mechanical and hydraulic properties of the granular material. This research investigated the mechanical effects of clay at grain-to-grain contacts in the presence of different fluids. Laboratory seismic wave propagation tests were conducted at ultrasonic frequencies using spherical glass beads coated with Montmorillonite clay (SWy-1) onto which different fluids were adsorbed. For all bead samples, seismic velocity increased and attenuation decreased as the contact stiffnesses increased with increasing stress demonstrating that grain contacts control seismic transmission in poorly consolidated and unconsolidated granular material. Coating the beads with clay added stiffness and introduced viscosity to the mechanical contact properties that increased the velocity and attenuation of the propagating seismic wave. Clay-fluid interactions were studied by allowing the clay coating to absorb water, ethyl alcohol, and hexadecane. Increasing water amounts initially increased seismic attenuation due to clay swelling at the contacts. Attenuation decreased for higher water amounts where the clay exceeded the plastic limit and was forced from the contact areas into the surrounding open pore space during sample consolidation. This work investigates how clay located at grain contacts affects the micromechanical, particularly seismic, behavior of granular materials. The need for this work is shown by a review of the effects of clays on seismic wave propagation, laboratory measurements of attenuation in granular media, and proposed mechanisms for attenuation in granular media.

  4. Polyamide 66/Brazilian Clay Nanocomposites

    Directory of Open Access Journals (Sweden)

    E. M. Araújo

    2009-01-01

    Full Text Available Polyamide 66 (PA66/Brazilian clay nanocomposites were produced via direct melt intercalation. A montmorillonite sample from the Brazilian state of Paraíba was organically modified with esthearildimethylammonium chloride (Praepagen, quaternary ammonium salt and has been tested to be used in polymer nanocomposites. The dispersion analysis and the interlayer spacing of the clay particles in matrix were investigated by X-ray diffraction (XRD and transmission electron microscopy (TEM. Thermal behavior of the obtained systems was investigated by differential scanning calorimetry (DSC, thermogravimetry (TG, and heat deflection temperature (HDT was reported too. The nanocomposites exhibited a partially exfoliated structure, very interesting HDT values which are higher than those of pure PA66, and good thermal stability.

  5. Effective stress law for the permeability of a limestone

    CERN Document Server

    Ghabezloo, Siavash; Guédon, Sylvine; Martineau, François

    2008-01-01

    The effective stress law for the permeability of a limestone is studied experimentally by performing constant head permeability tests in a triaxial cell with different conditions of confining pressure and pore pressure. Test results have shown that a pore pressure increase and a confining pressure decrease both result in an increase of the permeability, and that the effect of the pore pressure change on the variation of the permeability is more important than the effect of a change of the confining pressure. A power law is proposed for the variation of the permeability with the effective stress. The permeability effective stress coefficient increases linearly with the differential pressure and is greater than one as soon the differential pressure exceeds few bars. The test results are well reproduced using the proposed permeability-effective stress law. A conceptual pore-shell model based on a detailed observation of the microstructure of the studied limestone is proposed. This model is able to explain the ex...

  6. Experimental study on rheological deformation and stress properties of limestone

    Institute of Scientific and Technical Information of China (English)

    唐明明; 王芝银

    2008-01-01

    The systematic experiment regarding the general uniaxial compression test and the creep deformations of the typical limestones from the surrounding rock of the highway tunnels were made.The relationship between the axial stress and the delayed deformation steady value was obtained from the creep tests under low loading stresses.By the least square method,the parameters of Nishihara creep model were calculated from the creep curves.The results indicate that the strain change always lags behind the increase of stress,and the long-term strength of the limestone is about 80.6% of the stress at the volumetric strain reversal which is obtained from the conventional uniaxial compression test.

  7. Hands-on Virtual Clay

    OpenAIRE

    Pihuit, Adeline; Kry, Paul; Cani, Marie-Paule

    2008-01-01

    poster; International audience; This paper presents a new interaction system designed for hands-on 3D shape modeling and deformation through natural hand gestures. Our system is made of a Phantom haptic device coupled with a deformable foam ball that supports pressure sensors. These sensors detect forces exerted by the user's fingertips, and are used to control the configuration of a compliant virtual hand that is modeling soft virtual clay. During interaction, the user is provided both passi...

  8. Modified dry limestone process for control of sulfur dioxide emissions

    Science.gov (United States)

    Shale, Correll C.; Cross, William G.

    1976-08-24

    A method and apparatus for removing sulfur oxides from flue gas comprise cooling and conditioning the hot flue gas to increase the degree of water vapor saturation prior to passage through a bed of substantially dry carbonate chips or lumps, e.g., crushed limestone. The reaction products form as a thick layer of sulfites and sulfates on the surface of the chips which is easily removed by agitation to restore the reactive surface of the chips.

  9. Influence of pore system characteristics on limestone vulnerability: a laboratory study

    Science.gov (United States)

    Cultrone, G.; Russo, L. G.; Calabrò, C.; Uroševič, M.; Pezzino, A.

    2008-05-01

    Hyblean limestone of Oligo-Miocene age was widely used as a construction material in the architectural heritage of Eastern Sicily (Italy). Among them, the so-called Pietra Bianca di Melilli (Melilli limestone) and Calcare di Siracusa (Syracuse limestone) were prized for their attractive appearance, ease of quarrying, and workability. Syracuse limestone shows general weathering, whereas Melilli limestone is better preserved, and only differential erosion or superficial exfoliation can be detected in monuments. The cause of the different behavior of these two limestones was investigated from the petrographic and petrophysical points of view. The saturation coefficient is higher in Melilli limestone, and ultrasound measurements indicate that it is less compact than Syracuse limestone, so that Melilli limestone could deteriorate more easily than Syracuse limestone. However, pore interconnections and the size of very small pores play the main role in the durability of both materials. The “irregularity” of the Syracuse pore system and its greater number of micropores hinder water flow through the exterior, promote stress in pore structure, and favor the development of scaling, as confirmed by salt crystallization tests. In Melilli limestone, the low concentration of micropores and fast water evaporation allow solutions to reach the surface more easily, resulting in less damaging efflorescence.

  10. Porosity Investigation of Kosova's Clay

    Directory of Open Access Journals (Sweden)

    Makfire Sadiku

    2011-01-01

    Full Text Available Problem statement: Acid activated clay minerals are used as catalysts in the desulphurization of crude oil or as catalyst carrier, as drilling mud, as bleaching earth. Approach: The efficiency of the acid activation can be described in two ways. As increase of the surface and as increase of the cumulative pore volume after the activation. Results: In different samples of the clay mineral the activation was done with different sulfuric acid concentrations for two and 3h. Afterwards the specific surface was measured by means of nitrogen adsorption. All the measured isotherms belong to the pseudo-two kind. After the activation the surface enhanced from around 100-180 m2 g-1. The mesopore distribution is calculated out of the hysteresis between adsorption-desorption isotherms of the nitrogen. Conclusion: It is shown that the activation increases significantly the amount of mesopores which is reflected in the cumulative volume. The macrospore volume of the clay samples were measured by means of mercury intrusion porosimetry for pore sizes up to 320 nm. The volume of the macrospores results to an increase up to two times after the activation. The cumulative volume of all the pores is shown like a good parameter of the efficiency of the acid activation. The measurements were fulfilled in the newly equipped laboratory of the surface characterizations of the Tirana University. These analyses are of big interest for the industry in Albania and Kosove.

  11. Microfacies of Hallstatt Limestones near Silická Brezová

    Directory of Open Access Journals (Sweden)

    Katarína Kronome

    2009-01-01

    Full Text Available This work is focused on microfacies analysis of the Upper Triassic Hallstatt limestones occurring at the locality "Trench" – a section of the Silicic Unit near the Silická Brezová village. Classical methods of limestones study are amended by statistical methods. The section studied is built of Tuvalian to Sevatian sediments, i.e. upper parts of the Tisovec (Waxeneck Limestone, Hallstatt and Dachstein Limestones (the paper is focused mainly to the Hallstatt Limestone. They are developed in facies of bedded bioclastic limestones of greyish-pink and brick-red colour with signs of nodularity. These limestones sedimented mainly in open shelf environment communicating with deep water environment during the sedimentation.

  12. Guri limestone, a new hydrocargon reservoir in south Iran

    Energy Technology Data Exchange (ETDEWEB)

    Kashfi, M.S.

    1982-10-01

    The Guri Limestone Member of the Mishan Formation of Early to Middle Miocene age produces gas in the SE portion of the Zagros geosyncline. The Mishan Formation, which is predominantly marl in its type section near Khuzestan Province, becomes more agrillaceous with an increase in organic content towards the SE where the sequence thickens. In the SE portion of the Azgros geosyncline, the lower part of the Mishan changes to a highly-resistant, fossiliferous limestone which is called the Guri Limestone. This is of Late-Early Miocene age in most of the SE Zagros and rises in stratigraphic postion towards the NW, becoming of Middle Miocene age in Khuzestan Province. The Guri thickens considerably with massive reefal-type deposits towards the eastern end of the Fars Province near the Oman high. Lithological and geochemical studies support the hypothesis that the Mishan Formation could serve as a source rock for the hydrocarbons which have been found within the Guri. However, subsidence has failed to place the Mishan Formation within the thermal zone thought to be necessary for liquid hydrocarbon formation, and it is more likely that the deposits will produce gas.

  13. Preparation of Lime by Roasting the Limestone Deposits of Strezovci (Republic of Kosovo and Its Use for the Aluminothermic Production of Calcium Metal

    Directory of Open Access Journals (Sweden)

    Hoda, S.

    2013-03-01

    Full Text Available The goal of producing and processing limestone ore (mostly CaCO3 is to obtain high-quality refractory materials based on lime (CaO. Lime is the raw material for obtaining calcium metal as a strategic and fundamental component in lead metallurgy (production of refined lead, Pb-Ca alloys in the battery and cable industry, ferroalloys production with the addition of silicon and calcium, production of alloy steel and high-quality steel. This paper explores the preparation of lime by roasting the limestone deposits of Strezovci (Republic of Kosovo and its use for obtaining calcium through the aluminothermic process. Through research and analysis of the chemical composition of certain types of lime, its suitabi- lity for obtaining calcium metal was determined, and by analyzing the samples of the slag, determined was the possibility of its use in the production of fire-resistant cement for which the evaluation is needed. Based on previous research, the following was chosen: optimal composition of the cast, volume of added reducing agents, and conditions of the reduction process performance: temperature-time and initial vacuum. According to the authors’ knowledge, not one Southeast European country has applied this method, and it includes the use of by-products (slag, which can cause environmental pollution. The goal of this research was to prepare lime by roasting limestone of domestic origin in order to obtain calcium metal through the aluminothermic process. The procedure of calcium metal production includes the following operations: decarbonatization of limestone ore (CaCO3 , grinding of the obtained lime (CaO, homogenization of CaO and alumina, agglomeration, and aluminothermic reduction in vacuum furnaces. For the efficiency of the process, the most important technological operations are decarbonatization and reduction, provided the other operations are performed correctly. The estimated total world capacity for production of calcium metal is 25

  14. Coupled hydro-mechanical properties of Cobourg limestone with special reference to excavation damage zones

    Science.gov (United States)

    Nasseri, Mohammad H.; Sehizadeh, Mahdi; Ye, Sheng; Su, Grant; Nguyen, Son; Young, R. Paul

    2016-04-01

    Argillaceous rock formations being considered as potential host or cap rocks for the geological disposal of radioactive wastes are usually characterized by the presence of bedding planes, resulting in anisotropy of their strength and deformation properties. A laboratory experimental program was performed at the Rock Fracture Dynamics Facility at the University of Toronto to determine the coupled hydro-mechanical properties of the Cobourg limestone with special reference to its potential for damage. The program consists of triaxial tests with measurement of permeability using the pulse decay method and measurement of the seismic wave velocity at different stress levels. The tests were carried out on specimens parallel and perpendicular to the foliation planes within a geophysical imaging cell under different stress levels up to and beyond their peak strength. The specimens are characterized by random and irregular clay pockets and discontinuous argillaceous weak layers. Permeability of the specimens was measured with the pulse decay method under different pre - and post- failure deviatoric stresses. The specimens tested parallel to foliation planes show higher triaxial compressive strengths and higher axial strains at failure in comparison to the specimens tested perpendicular to the foliation planes. The permeability (k) values measured under different stress levels for all specimens show a consistent trend. The k value decreases with the stress increase at the beginning due to the closure of pre-existing fissures and beddings. The k value then increases continuously with the increase in the stress level with highest k values obtained at the post-failure stage. The evolution of the compressional and shear-wave velocities and shear wave splitting as a function of the axial stress is compatible with preferably oriented weak planes and with the evolution of the hydro-mechanical properties of the Cobourg limestone. From the test results, it can be interpreted that at

  15. Modernity and putty-clay

    Science.gov (United States)

    Ganesh, Trichur Kailas

    This dissertation addresses issues arising out of the problems of capital accumulation, productivity growth and 'putty-clay' technology. The concept of economic modernity occupies a central place in the subject-matter studied here in that it expresses both the incessant drive for newness that characterizes economic reality and the persistence of dated techniques that successfully resist replacement. This study examines the way in which an expansive development-theoretic 'putty-clay' framework may be employed to explain the historical processes behind both the avalanche of newness (innovations) and the conservatism of technology in the U.S. economy. The guiding link is the fixity of investments in physical capital equipment over time and space. The dilemma of fixed capital is studied in the context of the constant entrepreneurial search for flexibility and liquidity. The thesis advanced is that a development (Entwicklung)-theoretic 'putty-clay' conceptualization of the economic system adequately addresses the recurring problems of fixity, flexibility, and liquidity, and thereby permits important insights into the enigma surrounding the persistent productivity growth slowdown and 'stagflation' of the late sixties and seventies and the related phenomena of physical 'capital obsolescence' and the financial or 'speculative explosions' of our times. The notion of 'putty-clay' used here is an innovative one in that it departs from the growth-theoretic literature to re-appear as a Schumpeterian theory of modernity modified by a Veblenite view of an economic system directed by the exigencies of the 'machine-process'. The empirical aptitude of a macroeconomic 'putty-clay' model to explain capital obsolescence mediated by the energy 'crises' (supply shocks) of the seventies and eighties is examined in a separate chapter with results that differ markedly from the standard (Berndt and Wood) conclusions for the U.S. economy. The final chapter in the dissertation reverts to the

  16. Effect of Coarse Aggregate and Slag Type on the Mechanical Behavior of High and Normal Weight Concrete Used at Barrage Structure

    Directory of Open Access Journals (Sweden)

    Muhammad Sanaullah

    2017-04-01

    Full Text Available Present study is an effort to assess the composite effect of limestone aggregate and blast furnace slag on the mechanical characteristics of normal and high weight concrete at various structural units (barrage girders, main weir and block apron of New Khanki Barrage Project, Punjab. Mix designs for different concrete classes falling under the domain of high and normal weight concrete were prepared after aggregate quality testing. On attaining satisfactory results of quality testing nine concrete mixes were designed (three for each class: A1, A and B by absolute volume method (ACI- 211.1. The required compressive strength of normal and high strength was set at 6200, 5200 and 4200 Psi for the concrete types A1, A and B respectively after 28 days (ACI -318. For compressive strength assessment, a total 27 concrete cylinders were casted (9-cylinders for each mix and were water cured. The achieved average UCS of cylinder concrete specimens at 3, 7 and 28 days are 5170, 6338 and 7320 Psi for A1 – type, 3210, 4187 and 5602 Psi for A-type and 2650, 3360 and 4408 Psi for B- type mix. It has been found that all concrete mixes for suggested classes attained target strength at age of 7-days. The coarse aggregate (Margala Hill limestone and fine aggregates (from Lawrancepur /Qibla Bandi quarries used in all concrete mix designs have demonstrated a sound mechanical suitability for high and normal weight concrete.

  17. Corrosion Behavior of Ceramic Cup of Blast Furnace Hearth by Liquid Iron and Slag

    Science.gov (United States)

    Li, Yanglong; Cheng, Shusen; Wang, Zhifeng

    2016-10-01

    Three kinds of sample bricks of ceramic cups for blast furnace hearth were studied by dynamic corrosion tests based on different corrosion systems, i.e., liquid iron system, liquid slag system and liquid iron-slag system. Considering the influence of temperature and sample rotational speed, the corrosion profiles and mass loss of the samples were analyzed. In addition, the microstructure of the corroded samples was observed by optical microscope (OM) and scanning electron microscope (SEM). It was found that the corrosion profiles could be divided into iron corrosion region, slag corrosion region and iron-slag corrosion region via corrosion degree after iron-slag corrosion experiment. The most serious corrosion occurred in iron-slag corrosion region. This is due to Marangoni effect, which promotes a slag film formed between liquid iron and ceramic cup and results in local corrosion. The corrosion of the samples deepened with increasing temperature of liquid iron and slag from 1,623 K to 1,823 K. The variation of slag composition had greater influence on the erosion degree than that of rotational speed in this experiment. Taking these results into account the ceramic cup composition should be close to slag composition to decrease the chemical reaction. A microporous and strong material should be applied for ceramic cup.

  18. Micronutrientes in the sugarcane irrigated: correction of the soil with siderurgical slag

    Directory of Open Access Journals (Sweden)

    Napoleão Esberard de Macêdo Beltrão

    2009-12-01

    Full Text Available The beneficial effects of manuring with siderurgical slag has been researched in several species, mainly among grassy such as sugarcane (Saccharum officinarum L.. The experiment was installed in the field, using one of the most representative sugarcane soils of Alagoas State, was cultivated in Dystrophic AGREY ARGISSOIL. The siderurgical slag source was containing 11% of soluble SiO2. The objective this research was quantify foliate micronutrients in the sugarcane and pH of soil due siderurgical slag application submitted the different irrigation water in São Sebastião city. For such the design was band of randomizered blocks, with five doses of siderurgical slags (band and five water (sub band and four repetitions. The analyzed variables were the micronutrients concentrations (Zn, Cu, Fe and Mn in the leaf. The slag application increased the concentrations significantly foliate of Zn while concentrations of Cu and Fe decreased. The foliate concentration of Mn, in the interaction of slag and irrigation water, it decreased in the cane plants and first it would beat, when the factor was slag inside of irrigation water however, when the factor was sheets inside of slag, there was increase of the concentration this element us of the cycles. The foliate concentration of Mn, due the interactive effect of slag and irrigation water, decreased in the first cut. However, when the factor was irrigation water inside of slag, there was increase of concentration of this in the two cycles.

  19. Diffusion of hexavalent chromium in chromium-containing slag as affected by microbial detoxification.

    Science.gov (United States)

    Wang, Yunyan; Yang, Zhihui; Chai, Liyuan; Zhao, Kun

    2009-09-30

    An electrochemical method was used to determine the diffusion coefficient of chromium(VI) in chromium-containing slag. A slag plate was prepared from the original slag or the detoxified slag by Achromobacter sp. CH-1. The results revealed that the apparent diffusion coefficient of Cr(VI) was 4.4 x 10(-9)m(2)s(-1) in original slag and 2.62 x 10(-8)m(2)s(-1) in detoxified slag. The results implied that detoxification of chromium-containing slag by Achromobacter sp. CH-1 could enhance Cr(VI) release. Meanwhile, the results of laboratory experiment showed that the residual total Cr(VI) in slag decreased from an initial value of 6.8 mg g(-1) to 0.338 mg g(-1) at the end of the detoxification process. The Cr(VI) released from slag was also reduced by Achromobacter sp. CH-1 strain since water soluble Cr(VI) in the leachate was not detected after 4 days. Therefore, Achromobacter sp. CH-1 has potential application for the bio-detoxification of chromium-containing slag.

  20. An alternative approach for reusing slags from a plasma vitrification process

    Energy Technology Data Exchange (ETDEWEB)

    Kuo, Y.-M. [Department of Safety Health and Environmental Engineering, Chung Hwa University of Medical Technology, 89, Wenhwa 1st St., Rende Shiang, Tainan County 71703, Taiwan (China)], E-mail: yiming@mail.hwai.edu.tw; Tseng, H.-J. [Department of Foundry Engineering, National Tainan Industrial Vocational High School, Tainan 71075, Taiwan (China); Chang, J.-E. [Department of Environmental Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China); Sustainable Environment Research Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Wang, J.-W.; Wang, C.-T. [Department of Safety Health and Environmental Engineering, Chung Hwa University of Medical Technology, 89, Wenhwa 1st St., Rende Shiang, Tainan County 71703, Taiwan (China); Chen, H.-T. [Sustainable Environment Research Center, National Cheng Kung University, Tainan 70101, Taiwan (China)

    2008-08-15

    Vitrification is widely applied to transform hazardous materials into inert slags. Raising the value of the recycled slag is an important issue from an economic point of view. In this study, an alternative approach for mixing a plasma slag with unsaturated polyester resin for making the dough-like molding composites is proposed. Physical properties, including ultimate tensile strength, Rockwell hardness, and the elongation at break, were measured to evaluate the characteristics of the composites. A scanning electron microscope and an X-ray diffractometer were used to examine the micro characteristics of the specimens. The chemical stability of the composites was estimated using the toxicity characteristic leaching procedure and a hot water bathing process. In an optimal slag loading (mass ratio of slag to unsaturated polyester resin) ranged from 0.1 to 0.2, the slag powder improved the physical properties of the composites. With an increased slag loading, excess slag powder weakened the structure of the resin, reducing the ultimate tensile strength and Rockwell hardness. The acid and water bathing tests indicated that the resin is decomposed in a hot environment. However, the slag was not destructed nor were the hazardous metals leached out. The results show that the molding method is an effective technology to recycle the slag.

  1. Performance Evaluation and Field Application of Red Clay Green Roof Vegetation Blocks for Ecological Restoration Projects

    Directory of Open Access Journals (Sweden)

    Hwang-Hee Kim

    2017-02-01

    Full Text Available In this study, for restoration of ecological systems in buildings, porous vegetation red clay green roof blocks were designed for performance evaluation. Blast furnace slag (BFS; fine aggregates (agg., coarse aggregates, polyvinyl alcohol (PVA fiber (hydrophilic fiber, and red clay (ecofriendly additive material were applied to the construction of the porous vegetation red clay green roof blocks. A decrease in cement use is one way of reducing carbon emissions. To increase the water retentivity and the efficiency of roof vegetation blocks, blast furnace slag aggregates with excellent water absorptivity and polyvinyl alcohol fiber with a water absorption rate above 20% were added. In particular, the addition of polyvinyl alcohol fiber prevents performance reduction of the green roof vegetation blocks during freezing and melting in winter. Compressive strength, void ratio, and unit-mass tests were conducted to evaluate the performance of the roof vegetation blocks. After their application to roof vegetation, the effect of water purification was evaluated. According to the experimental results, the mix that satisfies the target performance of green roof vegetation blocks (compression strength above 8 MPa, void ratio above 20%, unit mass 2.0 kg/cm3 or below is: cement = 128.95 kg/m3, BFS = 96.75 kg/m3, red clay = 96.75 kg/m3, water = 81.50 kg/m3, BFS agg. = 1450 kg/m3, PVA fiber = 1.26 kg/m3. The green roof vegetation blocks were designed using the mix that satisfied the target performance. To find the amount of attainable water due to rainfall, a rainfall meter was installed after application of the roof vegetation to measure daily rainfall and calculate the amount of attainable water. The results show that, for 1 mm of rainfall, it is possible to attain about 0.53 L of water per 1 m2. In addition, the water quality of effluents after application of roof vegetation was analyzed, and the results satisfied Class 4 of the River-life Environmental

  2. Local corrosion of magnesia-chrome refractory at slag-metal interface; Yoyu slag metal kaimen ni okeru magnesia / chrom shitsu taikabutsu no kyokubu sonsho

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Z.; Mukai, K.; Ogata, M. [Kyushu Inst. of Tech., Kitakyushu, Fukuoka (Japan)

    1998-09-01

    The corrosion mode of refractory depending on the chemical dissolution of molten slag-metal, a component of refractory is classified mainly into the corrosion of inner slag phase body and inner metal phase body, and local corrosion at slag surface and slag-metal interface, and local corrosion at the interface of different type of refractories. Among them, local corrosion occurring at the slag-metal interface is a serious problem that effects the life of refractory, and these recent years research regarding the prevention of this type of local corrosion has been closed up. So far, number of researches regarding the local corrosion of solid oxides at slag-metal interface has been carried out. However, these are all based on close single component and research regarding the practical oxides with multiple components and multiporous characteristic has not been carried out. In this research, practical magnesia-chrome refractory (CaO-SiO2-Al203-FetO) slag-metal system is described and revelation of local corrosion phenomena at slag-metal interface was studied. 17 refs., 14 figs., 2 tabs.

  3. Effects of Design/Operating Parameters and Physical Properties on Slag Thickness and Heat Transfer during Coal Gasification

    Directory of Open Access Journals (Sweden)

    Insoo Ye

    2015-04-01

    Full Text Available The behaviors of the slag layers formed by the deposition of molten ash onto the wall are important for the operation of entrained coal gasifiers. In this study, the effects of design/operation parameters and slag properties on the slag behaviors were assessed in a commercial coal gasifier using numerical modeling. The parameters influenced the slag behaviors through mechanisms interrelated to the heat transfer, temperature, velocity, and viscosity of the slag layers. The velocity profile of the liquid slag was less sensitive to the variations in the parameters. Therefore, the change in the liquid slag thickness was typically smaller than that of the solid slag. The gas temperature was the most influential factor, because of its dominant effect on the radiative heat transfer to the slag layer. The solid slag thickness exponentially increased with higher gas temperatures. The influence of the ash deposition rate was diminished by the high-velocity region developed near the liquid slag surface. The slag viscosity significantly influenced the solid slag thickness through the corresponding changes in the critical temperature and the temperature gradient (heat flux. For the bottom cone of the gasifier, steeper angles were favorable in reducing the thickness of the slag layers.

  4. The microstructural evolution of clay-bearing carbonate faults during high-velocity friction experiments

    Science.gov (United States)

    Bullock, Rachael; De Paola, Nicola; Holdsworth, Robert

    2014-05-01

    Seismicity in the Northern Apennines, Italy, nucleates within and propagates through a multilayer sequence comprising limestones with marl interbeds. Observations from the Gubbio fault (1984, Ms = 5.2) indicate that the majority of earthquake displacement is localized within principal slip zones (PSZs), thermal decomposition of calcite. Initial microstructure of the wet gouges, on the other hand, is characterized by a distributed and interconnected network of wet clay surrounding calcite grains. The microstructure of the sheared wet gouges is characterized by a diffuse PSS, limited fabric development, and no PSZ; deformation is much more distributed. In addition, grain-size reduction in the wet gouges is ~1 order of magnitude less than in dry gouge equivalents. Thus, we attribute the contrasting frictional behaviour and microstructural evolution in the dry vs. wet gouges to the fact that in the wet gouges, distributed slip preferentially occurs on the pre-existing, weak clay network. This reduces the need for grain-breakage to occur before slip is able to localize, explaining the lack of a slip-hardening phase. Shear induced compaction of the wet clay-bearing gouges is also likely to generate a considerable pore-fluid overpressure within the impermeable clay network, further contributing to their weak behaviour. The lack of resistance to frictional sliding shown by the wet clay-bearing gouges contrasts with the traditional concept that phyllosilicates, due to their velocity-strengthening nature, should have a stabilizing role in upper crustal fault zones, and has significant implications for seismic hazard in the Apennines.

  5. Thermal stability of PMMA–clay hybrids

    Indian Academy of Sciences (India)

    Tanushree Choudhury; Nirendra M Misra

    2010-04-01

    Materials with small particle size are being extensively used in composites and hybrid materials. Exfoliated clay–polymer hybrids show enhanced properties. Exfoliation of clay platelets can be affected by selecting dispersing agents. In the present work, clay dispersed by natural dispersant (soap stone powder), cetyl trimethyl ammonium bromide (CTAB) dispersed clay and acid clay (amorphous clay) are taken. They are then polymerized with poly methyl methacrylate (PMMA) by solution intercalation method. The thermal stability of these different clay–PMMA hybrids have been studied and compared with that of pure PMMA by differential scanning calorimeter (DSC). The bonding of clay with PMMA has been studied by IR. Morphology of clay–PMMA hybrids has been shown by SEM and XRD which indicate partially exfoliated structure in T606-4 and intercalated structures in T606-6 and T606-2.

  6. Recycling of industrial waste and performance of steel slag green concrete

    Institute of Scientific and Technical Information of China (English)

    LI Yun-feng; YAO Yan; WANG Ling

    2009-01-01

    Workability and mechanical properties of steel slag green concrete with different types of steel slag and different dosages of admixtures were investigated. The effectiveness of steel slag powder on suppressing alkali aggregate reaction (AAR) expansion was assessed using the method of ASTM C441 and accelerated test method. Experimental results show that mechanical properties can be improved further due to the synergistic effect and mutual activation when compound mineral admixtures with steel slag powder and blast-furnace slag powder are mixed into concrete, in addition, about 50% decrease in expansion rate of mortar bars with mineral admixtures can be achieved in AAR tests. Mineral admixtures with steel slag powder as partial replacement for Portland cement in concrete is an effective means for controlling expansion due to AAR.

  7. The effect of primary copper slag cooling rate on the copper valorization in the flotation process

    Directory of Open Access Journals (Sweden)

    Aleksandar Mihajlović

    2015-06-01

    Full Text Available Technological procedure of slow cooling slag from primary copper production is applied in the purpose of copper recovery in the level of 98.5% to blister. This technological procedure is divided into two phases, first slow cooling of slag on the air for 24 hours, and then accelerated cooling with water for 48 hours. Within the research following methods were used: calculation of nonstationary slag cooling, verification of the calculation using computer simulation of slag cooling in the software package COMSOL Multiphysics and experimental verification of simulation results. After testing of the experimentally gained samples of slowly cooled slag it was found that this technological procedure gives the best results in promoting growth or coagulation of dispersed particles of copper sulfide and copper in the slag, thereby increasing the utilization of the flotation process with a decrease of copper losses through very fine particles.

  8. The estimation of the reaction stimulators influence into the extraction slag conditions

    Directory of Open Access Journals (Sweden)

    A. W. Bydałek

    2010-04-01

    Full Text Available Slag stimulators was analysed used the DTA methods. In the paper a method of determining the reduction capability of slag solutions wasused. The analysis of slag stimulators concertinaing of the chloride and fluoride compositions are showed. There are the oxides complexesused in to the slag composition for the purpose to establish two indicators in reduction processes: EW - indicator showing the direction and intensity of reaction in to the slag composition, and r - indicator of the rate of coal consumption. There are possible and purposeful the construction optimization programme engaging all of the phisics chemical influence the slags in processes of melting metals alloys. The proposed results, ranges of areas on graphs of phase equilibria's, demonstrative on the optimum values, will be verified in laboratory conditions and industrial. The initiation the new data the gathered base will be built in system of open base enabling.

  9. PRECIPITATION AND GROWTH OF PEROVSKITE PHASE IN TITANIUM BEARING BLAST FURNACE SLAG

    Institute of Scientific and Technical Information of China (English)

    Z.Z. Guo; T.P. Lou; L. Zhang; L.N. Zhang; Z.T. Sui

    2007-01-01

    The effects of transformation of slag composition and additive agents on the morphology, the crystal in the Ti-bearing blast furnace slags were investigated. As the morphology of perovskite is dispersed in molten slags, the crystal growth mechanism of the melting of fine dendrites and the coarsening of large grains exist throughout the solidification of molten slags. With the increase of CaO and Fe2O3 content, VF of perovskite obviously increases. However, high basicity leads to the viscosity of slag, which results in the reduction of the average equivalent diameter (AED). The experimental results showed that the presence of the additives CaF2 and MnO efficiently decreased the viscosity of the slags, and obviously improved the morphology of perovskite and promoted its growth.

  10. Corrosion behavior of steel in concrete made with slag-blended cement

    Energy Technology Data Exchange (ETDEWEB)

    Dehghanian, C. [Univ. of Technology, Isfahan (Iran, Islamic Republic of). Dept. of Chemical Engineering

    1999-03-01

    Concretes formulated with slag as a partial replacement for cement were used to evaluate the corrosion behavior of steel embedded in concrete, resistivity, and the compressive strength of the concrete. Corrosion rates and pitting corrosion of steel in concrete with up to 30% slag and exposed to sodium chloride (NaCl) solutions decreased. Slag-blended cement concrete increased concrete resistivity. A water-to-cement ratio <0.55 and submersion in water for a period of 18 days gave the best chloride (Cl{sup {minus}}) diffusion resistance from the external salt solutions. Compressive strength of the concrete decreased with addition of slag in the early ages of the concrete. After 5 months of age, compressive strength of the concrete increased with addition of slag. This trend continued with up to 30% slag addition.

  11. Modification of steelmaking slag by additions of salts from aluminum production

    Science.gov (United States)

    Walker, David C.

    The most common slag fluidizer in steelmaking is fluorspar, a mineral primarily composed of CaF2. Because of increasing consumption and decreasing availability of cheap fluorspar, steelmakers are seeking alternative means of achieving slag fluidity. One possible alternative to fluorspar is spent salt from secondary aluminum production. This salt is obtained from the used flux in remelting aluminum scrap and dross. This material is widely available and considered toxic (meaning that use in steelmaking helps to reduce environmental impacts from disposal). This project is an investigation of spent salt as a replacement for fluorspar in slag-fluidizing applications by viscosity measurements and weight loss measurements at high temperatures (to evaluate the amounts of gases are formed). In addition, characterization of raw materials and melted slags by XRD, chemical analysis, and EPMA have been undertaken. The spent salt addition has a positive effect on slag fluidity, and shows promise for use in slags.

  12. Mars, clays and the origins of life

    Science.gov (United States)

    Hartman, Hyman

    1989-01-01

    To detect life in the Martian soil, tests were designed to look for respiration and photosynthesis. Both tests (labeled release, LR, and pyrolytic release, PR) for life in the Martian soils were positive. However, when the measurement for organic molecules in the soil of Mars was made, none were found. The interpretation given is that the inorganic constituents of the soil of Mars were responsible for these observations. The inorganic analysis of the soil was best fitted by a mixture of minerals: 60 to 80 percent clay, iron oxide, quartz, and soluble salts such as halite (NaCl). The minerals most successful in simulating the PR and LR experiments are iron-rich clays. There is a theory that considers clays as the first organisms capable of replication, mutation, and catalysis, and hence of evolving. Clays are formed when liquid water causes the weathering of rocks. The distribution of ions such as aluminum, magnesium, and iron play the role of bases in the DNA. The information was stored in the distribution of ions in the octahedral and tetrahedral molecules, but that they could, like RNA and DNA, replicate. When the clays replicated, each sheet of clay would be a template for a new sheet. The ion substitutions in one clay sheet would give rise to a complementary or similar pattern on the clay synthesized on its surface. It was theorized that it was on the surface of replicating iron-rich clays that carbon dioxide would be fixed in the light into organic acids such as formic or oxalic acid. If Mars had liquid water during a warm period in its past, clay formation would have been abundant. These clays would have replicated and evolved until the liquid water was removed due to cooling of Mars. It is entirely possible that the Viking mission detected life on Mars, but it was clay life that awaits the return of water to continue its evolution into life based on organic molecules.

  13. Selective Clay Placement Within a Silicate-Clay Epoxy Blend Nanocomposite

    Science.gov (United States)

    Miller, Sandi G (Inventor)

    2013-01-01

    A clay-epoxy nanocomposite may be prepared by dispersing a layered clay in an alkoxy epoxy, such as a polypropylene oxide based epoxide before combining the mixture with an aromatic epoxy to improve the nanocomposite's thermal and mechanical properties.

  14. Ceramic clays from the western part of the Tamnava Tertiary Basin, Serbia: Deposits and clay types

    Directory of Open Access Journals (Sweden)

    Radosavljević Slobodan

    2014-01-01

    Full Text Available Based on geological, mineralogical, physical, chemical and technological investigations in the Tamnava Tertiary Basin near Šabac town (western Serbia, deposits of ceramic clays were studied. These ceramic clays are composed of kaolin-illite with a variable content of quartz, feldspars, mica, iron oxides and hydroxides, and organic matter. Four main types of commercial clays were identified: i red-yellow sandy-gravely (brick clays; ii grey-white poor sandy (ceramic clays; iii dark-carbonaceous (ceramic clays; and iv lamellar (“interspersed” fatty, poor sandy (highly aluminous and ferrous clays. Ceramic clays are defined as medium to high plastic with different ranges of sintering temperatures, which makes them suitable for the production of various kinds of materials in the ceramic industry. [Projekat Ministarstva nauke Republike Srbije, br. OI-176016

  15. Membrane behavior of clay liner materials

    Science.gov (United States)

    Kang, Jong Beom

    Membrane behavior represents the ability of porous media to restrict the migration of solutes, leading to the existence of chemico-osmosis, or the flow of liquid in response to a chemical concentration gradient. Membrane behavior is an important consideration with respect to clay soils with small pores and interactive electric diffuse double layers associated with individual particles, such as bentonite. The results of recent studies indicate the existence of membrane behavior in bentonite-based hydraulic barriers used in waste containment applications. Thus, measurement of the existence and magnitude of membrane behavior in such clay soils is becoming increasingly important. Accordingly, this research focused on evaluating the existence and magnitude of membrane behavior for three clay-based materials that typically are considered for use as liners for waste containment applications, such as landfills. The three clay-based liner materials included a commercially available geosynthetic clay liner (GCL) consisting of sodium bentonite sandwiched between two geotextiles, a compacted natural clay known locally as Nelson Farm Clay, and compacted NFC amended with 5% (dry wt.) of a sodium bentonite. The study also included the development and evaluation of a new flexible-wall cell for clay membrane testing that was used subsequently to measure the membrane behaviors of the three clay liner materials. The consolidation behavior of the GCL under isotropic states of stress also was evaluated as a preliminary step in the determination of the membrane behavior of the GCL under different effective consolidation stresses.

  16. The many ways of making anionic clays

    Indian Academy of Sciences (India)

    Michael Rajamathi; Grace S Thomas; P Vishnu Kamath

    2001-10-01

    Together with hydrotalcite-like layered double hydroxides, bivalent and trivalent metal hydroxides and their hydroxy salts are actually anionic clays consisting of positively charged hydroxide layers with anions intercalated in the interlayer region. The anionic clays exhibit anion sorption, anion diffusion and exchange properties together with surface basicity making them materials of importance for many modern applications. In this article, we discuss many different ways of making anionic clays and compare and contrast the rich diversity of this class of materials with the better-known cationic clays.

  17. Probing the water interactions in clay

    Energy Technology Data Exchange (ETDEWEB)

    Powell, D.H. [Lausanne Univ., Lausanne (Switzerland); Fischer, H.E. [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France); Skipper, N.T. [Univ. College, London (United Kingdom)

    1999-11-01

    Clays, the microscopic mineral fraction of soils, are probably the most important substrate for interactions between water, the mineral world and the biosphere. A knowledge of the structuring of water and hydrated metal ions near clays surfaces is of importance in environmental science, including toxic and radioactive waste disposal, and in the industrial application of clays. The smectite clays, with their large hydrated internal surface areas represent excellent model systems for the interactions of aqueous phases with solid surface. We present the results of neutron diffraction experiments using isotopic substitutions to probe the structure in the aqueous interlayer region of Li-montmorillonite. (authors) 6 refs., 3 figs.

  18. Optimisation of the slag mode in the ladle during the steel processing of secondary metallurgy

    OpenAIRE

    Socha, Ladislav; Bažan, Jiří; Gryc, Karel; Morávka, Jan; Styrnal, Petr; Pilka, Václav; Piegza, Zbygněv

    2013-01-01

    Optimisation of the slag mode in the ladle with the help of briquetted fluxing agents, based on Al2O3 under various technological conditions is the object of this paper. The aim of the industrial experiments was to assess the possibility of achieving the optimum chemical composition of the slag that would improve the kinetic conditions of the refining ladle slag during the treatment in secondary metallurgy units. Industrial experiments were focused on comparing the influences of d...

  19. Effects of slag-based silicon fertilizer on rice growth and brown-spot resistance.

    Directory of Open Access Journals (Sweden)

    Dongfeng Ning

    Full Text Available It is well documented that slag-based silicon fertilizers have beneficial effects on the growth and disease resistance of rice. However, their effects vary greatly with sources of slag and are closely related to availability of silicon (Si in these materials. To date, few researches have been done to compare the differences in plant performance and disease resistance between different slag-based silicon fertilizers applied at the same rate of plant-available Si. In the present study both steel and iron slags were chosen to investigate their effects on rice growth and disease resistance under greenhouse conditions. Both scanning electron microscopy (SEM and transmission electron microscopy (TEM were used to examine the effects of slags on ultrastructural changes in leaves of rice naturally infected by Bipolaris oryaze, the causal agent of brown spot. The results showed that both slag-based Si fertilizers tested significantly increased rice growth and yield, but decreased brown spot incidence, with steel slag showing a stronger effect than iron slag. The results of SEM analysis showed that application of slags led to more pronounced cell silicification in rice leaves, more silica cells, and more pronounced and larger papilla as well. The results of TEM analysis showed that mesophyll cells of slag-untreated rice leaf were disorganized, with colonization of the fungus (Bipolaris oryzae, including chloroplast degradation and cell wall alterations. The application of slag maintained mesophyll cells relatively intact and increased the thickness of silicon layer. It can be concluded that applying slag-based fertilizer to Si-deficient paddy soil is necessary for improving both rice productivity and brown spot resistance. The immobile silicon deposited in host cell walls and papillae sites is the first physical barrier for fungal penetration, while the soluble Si in the cytoplasm enhances physiological or induced resistance to fungal colonization.

  20. Sulphur dioxide removal using South African limestone/siliceous materials

    Energy Technology Data Exchange (ETDEWEB)

    D.O. Ogenga; M.M. Mbarawa; K.T. Lee; A.R. Mohamed; I. Dahlan [Tshwane University of Technology, Pretoria (South Africa)

    2010-09-15

    This study presents an investigation into the desulfurization effect of sorbent derived from South African calcined limestone conditioned with fly ash. The main aim was to examine the effect of chemical composition and structural properties of the sorbent with regard to SO{sub 2} removal in dry-type flue gas desulfurization (FGD) process. South African fly ash and CaO obtained from calcination of limestone in a laboratory kiln at a temperature of 900{sup o}C were used to synthesize CaO/ash sorbent by atmospheric hydration process. The sorbent was prepared under different hydration conditions: CaO/fly ash weight ratio, hydration temperature (55-75{sup o}C) and hydration period (4-10 h). Desulfurization experiments were done in the fixed bed reactor at 87{sup o}C and relative humidity of 50%. The chemical composition of both the fly ash and calcined limestone had relatively high Fe{sub 2}O{sub 3} and oxides of other transitional elements which provided catalytic ability during the sorbent sorption process. Generally the sorbents had higher SO{sub 2} absorption capacity in terms of mol of SO{sub 2} per mol of sorbent (0.1403-0.3336) compared to hydrated lime alone (maximum 0.1823). The sorbents were also found to consist of mesoporous structure with larger pore volume and BET specific surface area than both CaO and fly ash. X-ray diffraction (XRD) analysis showed the presence of complex compounds containing calcium silicate hydrate in the sorbents. 19 refs., 6 figs., 3 tabs.

  1. Physical Deterioration of Egyptian Limestone Affected by Saline Water

    Directory of Open Access Journals (Sweden)

    Mohammed EL-GOHARY

    2013-12-01

    Full Text Available This study is the second in a series of experiments that describe the chemical, physical and thermal properties of archaeological limestone affected by salt and saline water in Egypt. This research aims to study the aggressive physical effects of different types of salts dominated in saline water and their different mechanisms on the acceleration of weathering processes that affect Egyptian limestone. It presents a multidisciplinary approach to characterize, at both micro/macro scales, the behavior of a limestone widely used as a construction material in most of Egyptian monuments when interacting with some types of salt solutions of various concentrations. A systematic optical, morphological, physical and mechanical analysis of the fresh and weathered stone samples were used to evaluate different characteristics through using scientific some techniques such as optical microscope (OP and scanning electron microscope (SEM. In addition to the using of some special computer programs that were used to define different physical and mechanical properties such as weight changes, bulk density, total porosity, water uptake, water content, thermal dilatation and abrasion resistant. The results proved that all investigated samples were gradually affected by the types of salinity paths and salt concentrations. These results will serve as a database for the future comparison of long term behavior of stones before and after the planned conservation of the entire area. So, it is pertinent to device some scientific methods and interventions to reduce all factors of salt effects and removing their harmful aspects from historic fabric of the archaeological buildings through some scientific recommendations

  2. A novel process for comprehensive utilization of vanadium slag

    Science.gov (United States)

    Liu, Li-ying; Du, Tao; Tan, Wen-jun; Zhang, Xin-pu; Yang, Fan

    2016-02-01

    Traditional processes for treating vanadium slag generate a huge volume of solid residue and a large amount of harmful gas, which cause serious environmental problems. In this study, a new process for the comprehensive utilization of vanadium slag was proposed, wherein zeolite A and a V2O5/TiO2 system were synthesized. The structural properties of the as-synthesized zeolite A and the V2O5/TiO2 system were characterized using various experimental techniques, including X-ray diffraction, X-ray fluorescence, scanning electron microscopy, and infrared spectroscopy. The results reveal that zeolite A and the V2O5/TiO2 system are successfully obtained with high purity. The results of gas adsorption measurements indicate that the prepared zeolite A exhibits high selectivity for CO2 over N2 and is a candidate material for CO2 capture from flue-gas streams.

  3. Effect of Superfine Slag Powder on HPC Properties

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A superfine slag powder (SP) made from granulated blast furnace slag incorporating activators by using special millingtechnique, was used as supplementary cementitious material in high performance concrete (HPC), replacing part ofthe mass of normal Portland cement. The effects of the SP on the workability, mechanical and crack self-healingproperties of HPC were studied. The hydration process and microstructure characteristics were investigated by X-raydiffraction (XRD) and scanning electron microscopy (SEM) techniques, respectively. The crack self-healing capacitywas evaluated by Brazilian test. The test results indicate that the SP has especially supplementary effect on waterreducing and excellent property of better control of slump loss. The concrete flowability increases remarkably withthe increase of SP replacement level in the range of 20% to 50%. The compressive and splitting tensile strengthsof HPC containing SP are higher than the corresponding strength of the control concrete at all ages. The crackself-healing ability is highly dependent on SP content of HPC.

  4. Alkali based slagging: a case study from Leigh Creek

    Energy Technology Data Exchange (ETDEWEB)

    R.A. Creelman; J. Bamberry; L.A. Juniper; C. Ward [University of Western Sydney, Penrith South, NSW (Australia)

    2003-07-01

    A systematic study was undertaken at NRG Port Augusta Power station in South Australia to determine the cause of ash deposition (slagging) in the boilers. Conventional wisdom suggests that iron in the ash is generally a major player in furnace ash deposition; however, mineralogical and chemical analyses of the deposits showed that the binding phase was plagioclase feldspar, dominated by the sodic feldspar albite. The study resulted in recognition that the cause of the formation of ash deposits in the North Flinders furnaces was the result of the ingestion of sodium and calcium into the melt that bound the deposits. This finding was a breakthrough in understanding the deposition process within these furnaces, and emphasises that not all slagging is iron related and that systematic studies of deposits, coal and ash make fundamental contributions to understanding the ash deposition mechanisms. 9 refs., 5 figs., 2 tabs.

  5. Investigations of the properties of dredged limestone fill

    DEFF Research Database (Denmark)

    Foged, Niels; Gordon, Anne

    1999-01-01

    limestone fill that is pumped ito ponds of the reclamation site. The work utilised a number of geophysical and geotechnical investigation techniques in the field, supplemented with laboratory testing.The study of in-situ electrical resistivities revealed larger variations in the ground conditions than were...... expected on the basis of information available from borehole logs.Ground deformation moduli were evaluated within an area planned for a maintenance centre by DSBmateriel using the continuous surface wave method, in conjunction with retrospective forward modelling. deformation properties calculated from...

  6. Absorption spectra of crystalline limestones experimentally deformed or tectonised

    Science.gov (United States)

    Cervelle, B.; ChayéD'Albissin, M.; Gouet, G.; Visocekas, R.

    1982-11-01

    Diffuse-reflectance spectra have been measured for a series of samples of Carrara marble experimentally deformed under different cylindrical stress ( P = 0, 100, 250, 500, 980 bars). The creation of point defects that results has been shown up classically by irradiation with β rays (40 krads), thus producing a typical blue coloration linked with the formation of colour centres. The diffuse-reflectance spectra, measured on powders with a microscope-spectrometer in the visible range (400-800 nm), allow the determination of the absorption spectra by means of the Kubelka-Munk function. These absorption spectra have been measured for each of the deformed samples, as well as for different fractions of a very deformed specimen subsequently heated at temperatures between 100 and 500° C for a fixed time. In the same way, tectonised crystalline limestones, of various origins, were studied without any other treatment than the irradiation with β rays. From this study the following preliminary conclusions have been drawn: (1) The absorption spectrum of an undeformed but merely irradiated specimen of crystalline limestone is practically monotonous, but in the deformed specimens a broad band of absorption appears, having a maximum at 620 nm with several shoulders, the chief of which is at 520 nm. (2) This absorption band shows the existence of colour centres, the density of which can be estimated relatively by means of the chromaticity coordinates x and y of the C.I.E. obtained from the diffuse-reflectance spectra (C.I.E. = Commission Internationale de l'Éclairage). (3) An overgrinding of calcite generates defects that have the same spectra as those produced during the experimental deformation. Consequently, in obtaining the powders of grain size 50-80 μm needed for the diffuse spectrometry, great care must be exercised. (4) For a given confining pressure, the defect density is proportional to the deformation rate. (5) One can calibrate the effect of the annealing of

  7. Site investigations on cavernous limestone for the Remouchamps Viaduct, Belgium

    OpenAIRE

    Waltham, Antony; Vandenven, Georges; Ek, Camille

    1986-01-01

    POOR GROUND CONDITIONS on cavernous limestone created severe difficulties at the sites of four piers of the Remouchamps Viaduct. The discovery, during excavations for foundations, of large open cavities prompted a major re-appraisal of site investigation procedure, and also some redesign of the viaduct structure. La situation défavorable des fondations de quatre des piliers du viaduc autoroutier de Remouchamps posa des problèmes de construction. La présence de cavités karstiques largement ...

  8. Water transport in limestone by X-ray CAT scanning

    Science.gov (United States)

    Mossoti, Victor G.; Castanier, Louis M.

    1989-01-01

    The transport of water through the interior of Salem limestone test briquettes can be dynamically monitored by computer aided tomography (commonly called CAT scanning in medical diagnostics). Most significantly, unless evaporation from a particular face of the briquette is accelerated by forced air flow (wind simulation), the distribution of water in the interior of the briquette remains more or less uniform throughout the complete drying cycle. Moreover, simulated solar illumination of the test briquette does not result in the production of significant water gradients in the briquette under steady-state drying conditions.

  9. OPTIMALIZATION OF BLASTING IN »LAKOVIĆI« LIMESTONE QUARRY

    Directory of Open Access Journals (Sweden)

    Branko Božić

    1992-12-01

    Full Text Available The optimalization of exploitation in »Lakovići« limestone quarry is described. Based on determined discontinuities in the rock mass and their densities, the best possible working site have been located in order to obtain the best possible sizes of blasted rocks and work slope stability. Optimal lowest resistance line size for the quarry has been counted and proved experimentally. New blasting parameters have resulted in considerable saving of drilling and explosive (the paper is published in Croatian.

  10. 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.

  11. Microscopic Study of Carbon Surfaces Interacting with High Carbon Ferromanganese Slag

    Science.gov (United States)

    Safarian, Jafar; Kolbeinsen, Leiv

    2015-02-01

    The interaction of carbon materials with molten slags occurs in many pyro-metallurgical processes. In the production of high carbon ferromanganese in submerged arc furnace, the carbothermic reduction of MnO-containing silicate slags yields the metal product. In order to study the interaction of carbon with MnO-containing slags, sessile drop wettability technique is employed in this study to reduce MnO from a molten slag drop by carbon substrates. The interfacial area on the carbon substrate before and after reaction with slag is studied by scanning electron microscope. It is indicated that no Mn metal particles are found at the interface through the reduction of the MnO slag. Moreover, the reduction of MnO occurs through the contribution of Boudouard reaction and it causes carbon consumption in particular active sites at the interface, which generate carbon degradation and open pore growth at the interface. It is shown that the slag is fragmented to many micro-droplets at the reaction interface, potentially due to the effect on the interfacial energies of a provisional liquid Mn thin film. The rapid reduction of these slag micro-droplets affects the carbon surface with making deep micro-pores. A mechanism for the formation of slag micro-droplets is proposed, which is based on the formation of provisional micro thin films of liquid Mn at the interface.

  12. Environmental impacts of asphalt mixes with electric arc furnace steel slag.

    Science.gov (United States)

    Milačič, Radmila; Zuliani, Tea; Oblak, Tina; Mladenovič, Ana; Ančar, Janez Šč

    2011-01-01

    Electric arc furnace (EAF) steel slag can be used as an alternative high-quality material in road construction. Although asphalts with slag aggregates have been recognized as environmentally acceptable, there is a lack of data concerning the potential leaching of toxic Cr(VI) due to the highly alkaline media of EAF slag. Leaching of selected water extractable metals from slag indicated elevated concentrations of total chromium and Cr(VI). To estimate the environmental impacts of asphalt mixes with slag, leachability tests based on diffusion were performed using pure water and salt water as leaching agents. Compact and ground asphalt composites with natural aggregates, and asphalt composites in which the natural aggregates were completely replaced by slag were prepared. The concentrations of total chromium and Cr(VI) were determined in leachates over a time period of 6 mo. After 1 and 6 mo, the concentrations of some other metals were also determined in the leachates. The results indicated that chromium in leachates from asphalt composites with the addition of slag was present almost solely in its hexavalent form. However, the concentrations were very low (below 25 μg L) and did not represent an environmental burden. The leaching of other metals from asphalt composites with the addition of slag was negligible. Therefore, the investigated EAF slag can be considered as environmentally safe substitute for natural aggregates in asphalt mixes.

  13. SLAG CHARACTERIZATION AND REMOVAL USING PULSE DETONATION TECHNOLOGY DURING COAL GASIFICATION

    Energy Technology Data Exchange (ETDEWEB)

    DR. DANIEL MEI; DR. JIANREN ZHOU; DR. PAUL O. BINEY; DR. ZIAUL HUQUE

    1998-07-30

    Pulse detonation technology for the purpose of removing slag and fouling deposits in coal-fired utility power plant boilers offers great potential. Conventional slag removal methods including soot blowers and water lances have great difficulties in removing slags especially from the down stream areas of utility power plant boilers. The detonation wave technique, based on high impact velocity with sufficient energy and thermal shock on the slag deposited on gas contact surfaces offers a convenient, inexpensive, yet efficient and effective way to supplement existing slag removal methods. A slight increase in the boiler efficiency, due to more effective ash/deposit removal and corresponding reduction in plant maintenance downtime and increased heat transfer efficiency, will save millions of dollars in operational costs. Reductions in toxic emissions will also be accomplished due to reduction in coal usage. Detonation waves have been demonstrated experimentally to have exceptionally high shearing capability, important to the task of removing slag and fouling deposits. The experimental results describe the parametric study of the input parameters in removing the different types of slag and operating condition. The experimental results show that both the single and multi shot detonation waves have high potential in effectively removing slag deposit from boiler heat transfer surfaces. The results obtained are encouraging and satisfactory. A good indication has also been obtained from the agreement with the preliminary computational fluid dynamics analysis that the wave impacts are more effective in removing slag deposits from tube bundles rather than single tube. This report presents results obtained in effectively removing three different types of slag (economizer, reheater, and air-heater) t a distance of up to 20 cm from the exit of the detonation tube. The experimental results show that the softer slags can be removed more easily. Also closer the slag to the exit of

  14. 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.

  15. Effects of Carbo-Nitridation Process of Ti-Bearing Blast Furnace Slag on Iron Content

    Science.gov (United States)

    Shi, Z.; Zhang, X. M.; Xu, Y.

    In order to prepare corrosion-resistant refractory material, experiment chooses Ti-bearing Blast Furnace Slag as raw materials which were treated by the method of carbo-nitridation. Finally, the corrosion resistance properties of the material can be improved by this method. The carbo-nitridation process affects the iron content of the slag in the study, which have a beneficial effect on the synthesis of Ti (C. N). The results indicated that the iron content of the slag significantly increased in process of Ti (C. N) synthesis: and the iron content of slag showed an upward trend with the increase of holding time.

  16. Gasification slag rheology and crystalline phase formation in titanium-calcium-alumina-silica-rich glass

    Energy Technology Data Exchange (ETDEWEB)

    Brooker, D.D. [Texaco, Inc., Beacon, NY (United States); Oh, M.S. [Hongik Univ., Seoul (Korea, Republic of)

    1996-10-01

    The Texaco Gasification Process employs a high temperature and pressure slagging gasifier, in which the viscosity of the slag plays a key role in determining operating conditions. The empirical models available in the literature as well as laboratory testing have concentrated on low titanium feeds. During the gasification of waste material, titanium oxide will become an important element in controlling the ash and slag behavior. Slag viscosity was measured at temperatures in the range of 1150-1500{degrees}C under reducing atmosphere with 0-30% titanium in combination with calcium-alumina-silica rich feeds to gain a better understanding of the slag theology. The slag viscosities with most titanium-rich slags showed the behavior of a crystalline slag with T{sub cv} of 1250{degrees}C. Crystalline phase analyses of the slag samples revealed that titanium oxide crystal will nucleate, but the glass phase is dominated by calcium-titanium-silicate and calcium-alumina-silicate glasses which have low melting points.

  17. Smelting reduction and kinetics analysis of magnetic iron in copper slag using waste cooking oil.

    Science.gov (United States)

    Li, Bo; Wang, Xubin; Wang, Hua; Wei, Yonggang; Hu, Jianhang

    2017-05-25

    To improve the recovery of copper, the viscosity of copper molten slag is decreased by the reduction of magnetic iron, which, in turn, accelerates the settling and separation of copper droplets from the slag. A new technology is proposed in which waste cooking oil is used as a reductant to reduce magnetic iron in the copper smelting slag and consequently reduce carbon emissions in the copper smelting process. A kinetic model of the reduction of magnetic iron in copper slag by waste cooking oil was built using experimental data, and the accuracy of the model was verified. The results indicated that the magnetic iron content in the copper slag decreased with increasing reduction time and an increase in temperature more efficiently reduced magnetic iron in the copper slag. The magnetic iron in the copper slag gradually transformed to fayalite, and the viscosity of the copper molten slag decreased as the magnetic iron content decreased during the reduction process. The reduction of magnetic iron in the copper molten slag using waste cooking oil was a first-order reaction, and the rate-limiting step was the mass transfer of Fe3O4 through the liquid boundary layer.

  18. The influence of the silicate slag composition on copper losses during smelting of the sulfide concentrates

    Directory of Open Access Journals (Sweden)

    Živković Živan

    2009-01-01

    Full Text Available This paper presents the results of multi-linear regression analysis (MLRA of the slag composition (SiO2, FeO, Fe3O4, CaO, Al2O3 and the content of copper in the matte on resulting copper content in the slag during smelting of the sulfide concentrates in the reverberatory furnace. When comparing results obtained with MLRA model calculations with values measured at industrial level high degree of fitting is obtained (R2 = 0.974. This indicates that slag composition and content of copper in the matte influences the copper losses in the waste slag with the probability of 95 %.

  19. Use of copper slag in glass-epoxy composites for improved wear resistance.

    Science.gov (United States)

    Biswas, Sandhyarani; Satapathy, Alok

    2010-07-01

    Copper slag is a by-product obtained during matte smelting and refining of copper. The common management options for copper slag are recycling, recovery of metal and production of value-added products. In the present study using copper slag as a filler in glass-epoxy composites, the tensile modulus increased from 8.77 GPa to 9.64 GPa when using up to 10 wt% of copper slag but on further addition of copper slag (up to 20 wt%), the tensile modulus started to decrease down to 7.11 GPa. Similar trends were observed in the case of flexural strength and interlaminar shear strength. With the incorporation of copper slag particles, the impact strength increased about 10-15%. This work includes the processing, characterization and study of the erosion behaviour of a class of such copper slag filled glass-epoxy composites based on Taguchi's experimental approach to characterise erosion behaviour. The results show that peak erosion takes place at an impingement angle of 60 degrees for the unfilled composites whereas for the copper slag filled glass-epoxy composites it occurs at a 45 degrees impingement angle. This paper considers the possible utilisation of copper slag as filler material for the preparation of composite materials and preparation of added-value products such as abrasive tools, cutting tools and railroad ballast.

  20. Technological progress on detoxification and comprehensive utilization of chromium-containing slag

    Institute of Scientific and Technical Information of China (English)

    柴立元; 何德文; 于霞; 刘恢; 闵小波; 陈为亮

    2002-01-01

    Chromium salt is an important industrial material, but vast waste slag containing chrome(Ⅵ) is brought out in the process of its production. The slag is seriously harmful to environments and human health. The technologies on detoxification and comprehensive utilization of chromium-containing slag were summarized abroad and at home. And various methods were also described for the detoxification mechanism, technology process, and practical application effects in detail. A new concept for detoxification of chromium-containing slag, furthermore, was put forward by using microorganism.

  1. The Early Strength of Slag Cements with Addition of Hydrate Microcrystals

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The effect of hydrate microcrystals such as calcium silicate hydrates (CSH) and ettringite on the early strength of slag cements was studied.The authors explored the possibility of improving the early strength of the slag cement by applying crystal seed technology.It is shown that slag crystal seeds make the early strength of the cement increased due to the action of hydrate crystal seeds,which speed up the hydration of clinker minerals in the nucleation of ettringite.Therefore,the early strength of the slag cement is obviously improved.

  2. Use of steel slag as a granular material: volume expansion prediction and usability criteria.

    Science.gov (United States)

    Wang, George; Wang, Yuhong; Gao, Zhili

    2010-12-15

    The theoretical equation for predicting volume expansion of steel slag is deduced based on both chemical reaction and physical changes of free lime in steel slag during the hydration process. Laboratory volume expansion testing is conducted to compare the results with the theoretical volume expansion. It is proved that they correlated well. It is furthermore experimentally proved that certain volume expansion of steel slag can be absorbed internally by the void volume in bulk steel slag under external surcharge weight making the apparent volume expansion equal zero. The minimum (lowest) absorbable void volume is approximately 7.5%, which is unrelated to the free lime content. A usability criterion is then developed based on the volume expansion of steel slag (%) and the minimum percentage of the volume that can take the volume expansion of steel slag (%). Eventually the criterion (relationship) is established based on the free lime content, the specific gravity and bulk relative gravity of a specific steel slag sample. The criteria can be used as guidance and specification for the use of steel slag and other expansion-prone nonferrous slags, copper, nickel for instance as a granular material in highway construction.

  3. 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.

  4. Heating and melting mechanism of stainless steelmaking dust pellet in liquid slag

    Institute of Scientific and Technical Information of China (English)

    PENG ji; TANG Mo-tang; PENG Bing; YU Di; J.A.KOZINSKl; TANG Chao-bo

    2007-01-01

    The heating and melting mechanisms of the pellets immersed in liquid slag were investigated. and the effect of the pellet heating and the melting conditions were studied. The results show that the dust component in the pellet is melted from the surface and no metallic elements are melted before the dust component, the time for the pellet completely melted is reduced as the iron powder content increases since the metallic iron has high thermal conductivity. These are four stages of heating and melting of pellet in liquid slag, they are the growth and melt of solid slag shell, penetration of liquid slag, dissolving of dust component and melring of reduced metals.The lifetime of the solid slag shell is in the range of 7-16 s and increasing the pre-heating temperature of the pellet and the slag temperature can shorten the slag shell liretime. The time for the dust component in the pellet to be melted completely is in the range of 20-45 s and increasing the pre-heating temperature, especially in the range of 600-800 ℃.can obviously reduce the melting time. A higher slag temperature can also improvethe pellet melting and the melting time is reduced by l0-15 s when the slag temperature is increased from 1 450 to 1 550 ℃.The pellet with higher content of iron powder is beneficial to the melting by improving the heat conductivity.

  5. Electrokinetically Enhanced Delivery for ERD Remediation of Chlorinated Ethenes in a Fractured Limestone Aquifer

    DEFF Research Database (Denmark)

    Broholm, Mette Martina; Hansen, Bente H.; With Nedergaard, Lærke;

    Leakage of the chlorinated solvents PCE and TCE into limestone aquifers from contaminated overburden and the long-lasting back diffusion from the secondary source in the limestone matrix pose a severe risk for contamination of drinking water resources. Dechlorination of PCE and TCE in limestone...... often accumulates cis-DCE due to incomplete dechlorination in the limestone aquifers, as observed downgradient of a PCE and TCE DNAPL source area at Naverland in Denmark. A microcosm study with limestone core material and groundwater from the Naverland site source area spiked with PCE showed...... that enhanced reductive dechlorination (ERD) by the addition of donor and specific degraders (KB1® culture) can lead to complete dechlorination of PCE and TCE in the limestone aquifer, provided sufficient contact between specific degraders, donor and specific degraders, is obtained. Advection-based delivery...

  6. Kinetic Hydration Heat Modeling for High-Performance Concrete Containing Limestone Powder

    Directory of Open Access Journals (Sweden)

    Xiao-Yong Wang

    2017-01-01

    Full Text Available Limestone powder is increasingly used in producing high-performance concrete in the modern concrete industry. Limestone powder blended concrete has many advantages, such as increasing the early-age strength, reducing the setting time, improving the workability, and reducing the heat of hydration. This study presents a kinetic model for modeling the hydration heat of limestone blended concrete. First, an improved hydration model is proposed which considers the dilution effect and nucleation effect due to limestone powder addition. A degree of hydration is calculated using this improved hydration model. Second, hydration heat is calculated using the degree of hydration. The effects of water to binder ratio and limestone replacement ratio on hydration heat are clarified. Third, the temperature history and temperature distribution of hardening limestone blended concrete are calculated by combining hydration model with finite element method. The analysis results generally agree with experimental results of high-performance concrete with various mixing proportions.

  7. Low-Chrome/Chrome Free Refractories for Slagging Gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, J.P.; Kwong, K.-S.; Powell, C.P.; Thomas, H.; Petty, A.V., Jr.

    2007-01-01

    Gasifiers are containment vessels used to react carbon-containing materials with oxygen and water, producing syngas (CO and H2) that is used in chemical and power production. It is also a potential source of H2 in a future hydrogen economy. Air cooled slagging gasifiers are one type of gasifier, operating at temperatures from 1275-1575º C and at pressures of 400 psi or higher. They typically use coal or petroleum coke as the carbon source, materials which contain ash impurities that liquefy at the gasification temperatures, producing liquid slag in quantities of 100 or more tons/day, depending on the carbon fed rate and the percent ash present in the feedstock. The molten slag is corrosive to refractory linings, causing chemical dissolution and spalling. The refractory lining is composed of chrome oxide, alumina, and zirconia; and is replaced every 3-24 months. Gasifier users would like greater on-line availability and reliability of gasifier liners, something that has impacted gasifier acceptance by industry. Research is underway at NETL to improve refractory service life and to develop a no-chrome or low-chrome oxide alternative refractory liner. Over 250 samples of no- or low-chrome oxide compositions have been evaluated for slag interactions by cup testing; with potential candidates for further studies including those with ZrO2, Al2O3, and MgO materials. The development of improved liner materials is necessary if technologies such as IGCC and DOE’s Near Zero Emissions Advanced Fossil Fuel Power Plant are to be successful and move forward in the marketplace.

  8. Performance of steel-making slag concrete reinforced with fibers

    OpenAIRE

    Ortega-López Vanesa; Fuente-Alonso José Antonio; Skaf Marta; Santamaría Amaia; Aragón Ángel; Manso Juan Manuel

    2017-01-01

    In this research, the possibility of making concrete reinforced with fibers and manufactured with recycled aggregates from carbon steel production was explored. Electric arc furnace slag (EAFS) was used as coarse and medium aggregate, and part of the sand sizes. Metallic and synthetic fibers were added in different amounts. Initially, the properties of EAFS and their suitability to be used in the manufacture fiber reinforced concrete were analysed. Then, a series of fiber reinforced concrete ...

  9. Slag characterization and removal using pulse detonation for coal gasification. Quarterly research report, July 1--September 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Huque, Z.; Mei, D.; Biney, P.O.; Zhou, J.; Ali, M.R.

    1996-10-25

    Boiler slagging and fouling as a result of inorganic impurities in combustion gases being deposited on heat transfer tubes have caused severe problems in coal-fired power plant operation. These problems are fuel, system design, and operating condition dependent. Conventional slag and ash removal methods include the use of in situ blowing or jet-type devices such as air or steam soot blowers and water lances. Pulse detonation technology for the purpose of removing slag and fouling deposits in coal-fired utility power plant boilers offers great potential. The detonation wave technique based on high impact velocity with sufficient energy and thermal shock on the slag deposited on gas contact surfaces offers a convenient, inexpensive, yet efficient and effective way to supplement existing slag removal methods. These detonation waves have been demonstrated experimentally to have exceptionally high shearing capability important to the task of removing slag and fouling deposits. Several tests have been performed with single shot detonation wave at University of Texas at Arlington to remove the slag deposit. To hold the slag deposit samples at the exit of detonation tube, two types of fixture was designed and fabricated. They are axial arrangement and triangular arrangement. The slag deposits from the utility boilers have been used to prepare the slag samples for the test. The experimental results show that the single shot detonation wave is capable of removing the entire slag (types of slag deposited on economizer, and air-heater, i.e., relatively softer slags) and 30% of the reheater slag (which is harder) even at a distance of 6 in. from the exit of a detonation engine tube. Wave strength and slag orientation also have different effects on the chipping off of the slag. The annual report discusses about the results obtained in effectively removing the slag.

  10. Sulfide Capacity in Ladle Slag at Steelmaking Temperatures

    Science.gov (United States)

    Allertz, Carl; Sichen, Du

    2015-12-01

    Sulfide capacity measurements were conducted at 1823 K and 1873 K (1550 °C and 1600 °C) for the quaternary Al2O3-CaO-MgO-SiO2 system, for typical compositions used in the ladle in steelmaking. A copper-slag equilibrium was used under controlled oxygen and sulfur potentials. The sulfide capacity is strongly dependent on the composition and it was found to increase with the basic oxides, while it decreases with increase of the acidic components. It was found that CaO is more effective in holding sulfur in the slag compared to MgO when replacing SiO2. For the present slag compositions, Al2O3 and SiO2 behaved similar with respect to sulfur, and no considerable effect could be recorded when replacing one for the other. The sulfide capacity was also found to be strongly dependent on the temperature, increasing with temperature. The present results were compared with industrial data from the ladle, after vacuum treatment, and they were in good agreement.

  11. Selective Sulfidation of Lead Smelter Slag with Sulfur

    Science.gov (United States)

    Han, Junwei; Liu, Wei; Wang, Dawei; Jiao, Fen; Qin, Wenqing

    2016-02-01

    The selective sulfidation of lead smelter slag with sulfur was studied. The effects of temperature, sulfur dosage, carbon, and Na salts additions were investigated based on thermodynamic calculation. The results indicated that more than 96 pct of zinc in the slag could be converted into sulfides. Increasing temperature, sulfur dosage, or Na salts dosage was conducive to the sulfidation of the zinc oxides in the slag. High temperature and excess Na salts would result in the more consumption of carbon and sulfur. Carbon addition not only promoted the selective sulfidation but reduced the sulfur dosage and eliminated the generation of SO2. Iron oxides had a buffering role on the sulfur efficient utilization. The transformation of sphalerite to wurtzite was feasible under reducing condition at high temperature, especially above 1273 K (1000 °C). The growth of ZnS particles largely depended upon the roasting temperature. They were significantly increased when the temperature was above 1273 K (1000 °C), which was attributed to the formation of a liquid phase.

  12. Alternative concrete based on alkali-activated slag

    Directory of Open Access Journals (Sweden)

    Puertas, F.

    2008-09-01

    Full Text Available This article reports the results of related to on the performance of concrete made with waterglass (Na2SiO3•nH2O + NaOH-activated Colombian granulated blast furnace slag. The mechanical strength and durability properties this alkali-activated slag concrete (AAS were compared to the properties of ordinary Portland cement concrete (OPC with the same proportion of binder, which ranged from 340 to 512 kg per m3 of concrete. The results indicated that increasing the proportion of slag led to improvements in the properties studied.El propósito de este artículo es dar a conocer los resultados de la evaluación del comportamiento de mezclas de hormigón producidas a partir de la activación con waterglass (Na2SiO3•nH2O + NaOH de una escoria siderúrgica granulada de alto horno colombiana. Las propiedades mecánicas y de durabilidad de los hormigones activados alcalinamente (AAS se comparan con las correspondientes mezclas de hormigón de cemento Portland (OPC producidas con igual proporción de ligante. Estas proporciones variaron entre 340 y 512 kg por m3 de hormigón. Los resultados obtenidos indican que incrementos en la proporción de la escoria contribuye a la mejora de las propiedades evaluadas.

  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. Application of Improved HMM Algorithm in Slag Detection System

    Institute of Scientific and Technical Information of China (English)

    TAN Da-peng; LI Pei-yu; PAN Xiao-hong

    2009-01-01

    To solve the problems of ladle slag detection system (SDS),such as high cost,short service life,and inconvenient maintenance,a new SDS realization method based on hidden Markov model (HMM) was put forward.The physical process of continuous casting was analyzed,and vibration signal was considered as the main detecting signal according to the difference in shock vibration generated by molten steel and slag because of their difference in density.Automatic control experiment platform oriented to SDS was established,and vibration sensor was installed far away from molten steel,which could solve the problem of easy power consumption by the sensor.The combination of vector quantization technology with learning process parameters of HMM was optimized,and its revaluation formula was revised to enhance its recognition effectiveness.Industrial field experiments proved that this system requires low cost and little rebuilding for current devices,and its slag detection rate can exceed 95 %.

  15. The Chloride Permeability of Persulphated Phosphogypsum-Slag Cement Concrete

    Institute of Scientific and Technical Information of China (English)

    HUANG Youqiang; LU Jianxin; CHEN Feixiang; SHUI Zhonghe

    2016-01-01

    The chloride permeability and microstructure of persulphated phosphogypsum-slag cement concrete (PPSCC), the Portland slag cement concrete (PSCC) and ordinary Portland cement concrete (OPCC) were investigated comparatively. Some test methods were used to evaluate the chloride permeability and explain the relationship between the permeability and microstructure of concrete. The results show that the resistance to chloride penetration in PPSCC is signiifcantly better than that in OPCC, the reasons are as follows: 1) the slag in PPSCC is activated by clinker (alkali activation) and phosphogypsum (sulfate activation), forming more low Ca/Si C-S-H gel and gel pores below 10 nm than OPCC, improving the resistance to chloride penetration; 2) the hydration products of PPSCC have a much stronger binding capacity for chloride ions; and 3) in the same mix proportion, PPSCC has a better workability without large crystals calcium hydroxide in the hydration products, the interfacial transition zone (ITZ) is smoother and denser, which can cut off the communicating pores between the pastes and aggregates.

  16. Alkali Aggregate Reaction in Alkali Slag Cement Mortars

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    By means of "Mortar Bar Method",the ratio of cement to aggregate was kept as a constant 1∶2.25,the water-cement ratio of the mixture was 0.40,and six prism specimens were prepared for each batch of mixing proportions with dimensions of 10×10×60mm3 at 38±2℃ and RH≥95%, the influences of content and particle size of active aggregate, sort and content of alkali component and type of slag on the expansion ratios of alkali-activated slag cement(ASC) mortars due to alkali aggregate reaction(AAR) were studied. According to atomic absorption spectrometry,the amount of free alkali was measured in ASC mortars at 90d.The results show above factors affect AAR remarkably,but no dangerous AAR will occur in ASC system when the amount of active aggregate is below 15% and the mass fraction of alkali is not more than 5% (Na2O).Alkali participated in reaction as an independent component, and some hydrates containing alkali cations were produced, free alkalis in ASC system can be reduced enormously.Moreover,slag is an effective inhibitor, the possibility of generating dangerous AAR in ASC system is much lower at same conditions than that in ordinary Portland cement system.

  17. Simulation of past exposure in slag wool production.

    Science.gov (United States)

    Fallentin, B; Kamstrup, O

    1993-08-01

    A survey of the working conditions at a Danish slag wool production factory during the early technological phase in the 1940s is presented. No exposure data, however, are available for that period. So, a full-scale simulation of the past production of slag wool has been performed. Air monitoring was carried out in the working area around the cupola furnace. The aim was to measure exposure to air pollutants other than fibres. Such exposure might have confounded a possible association between lung cancer and exposure to fibres, in the early technological phase of slag wool production. The simulation experiment demonstrated exposure to PAH, a known lung carcinogen. The effect of other concurrent exposures is difficult to assess. Time-weighted average concentrations of particulate material ranged between 12.9 and 49.1 mg m-3 at the upper decks around the cupola. Corresponding concentrations of the dominant metals zinc and lead were 4.4-22.7 mg Zn m-3 and 0.9-4.7 mg Pb m-3. Significant concentrations of PAH up to 269 micrograms PAH m-3 (4 micrograms BaP m-3) occurred during ignition of the cupola furnace. The carbon monoxide level reached 270 ppm also during ignition.

  18. Speciation of copper in the thermally stabilized slag

    Energy Technology Data Exchange (ETDEWEB)

    Tuan, Y.-J. [Department of Environmental Engineering, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan (China); Sustainable Environment Research Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Paul Wang, H., E-mail: wanghp@mail.ncku.edu.t [Department of Environmental Engineering, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan (China); Sustainable Environment Research Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Chang, J.-E. [Department of Environmental Engineering, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan (China); Sustainable Environment Research Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Chao, C.-C. [Sustainable Environment Research Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Tsai, C.-K. [Department of Environmental Engineering, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan (China)

    2010-07-21

    The Taiwan universities laboratory hazardous wastes have been treated by incineration at the temperature range of 1173-1273 K. By X-ray absorption near edge structure (XANES) spectroscopy, mainly CuO and CuSO{sub 4} are found in the incineration bottom and fly ashes. The incineration fly ash can be stabilized thermally at 1773 K in the plasma melting reaction chamber (integrated with the incinerator), and converted to slag. The concentration of leachable copper in the slag is reduced significantly mainly due to the fact that copper is encapsulated in the SiO{sub 2} matrix. In addition, the refined extended X-ray adsorption fine structure (EXAFS) spectra of copper also indicate formation of the Cu-O-Si species in the slag as the bond distances of 1.95 A for Cu-O and 2.67 A for O-Si are observed. This work exemplifies utilization of the synchrotron X-ray absorption spectroscopy to facilitate the thermal stabilization treatments of the fly ash hazardous waste using the plasma melting method.

  19. Estimation of slagging in furnaces; Kuonaavuuden ennustaminen kivihiilen poelypoltossa

    Energy Technology Data Exchange (ETDEWEB)

    Jacobson, T.; Jaeaeskelaeinen, K.; Oeini, J.; Koskiahde, A.; Jokiniemi, J.; Pyykkoenen, J. [Imatran Voima Oy, Vantaa (Finland)

    1997-10-01

    Understanding and estimation of slagging in furnaces is essential in the design of new power plants with high steam values or in modifications like low-NO{sub x} retrofits in existing furnaces. Major slagging yields poor efficiency, difficult operation and high maintenance costs of the plant. The aim of the project is to develop a computational model for slagging in pulverized coal combustion. The model is based on Computer Controlled Scanning Electron Microscopy (CCSEM) analysis of mineral composition of the coal and physical models for behaviour of minerals inside a furnace. The analyzed mineral particles are classified to five composition classes and distributed to calculational coal particles if internal minerals of coal. The calculational coal particles and the external minerals are traced in the furnace to find out the behaviour of minerals inside the furnace. If the particle tracing indicates that the particle hits the heat transfer surface of the furnace the viscosity of the particle is determined to see if particle is sticky. The model will be implemented to 3D computational fluid dynamics based furnace simulation environment Ardemus which predicts the fluid dynamics, heat transfer and combustion in a furnace. (orig.)

  20. Clay membrane made of natural high plasticity clay

    DEFF Research Database (Denmark)

    Foged, Niels; Baumann, Jens

    1998-01-01

    has been evaluated using standardised methods related to mineralogy, classification, compaction and permeability, and initial studies of diffusion properties have been carried out. Furthermore, at a test site the construction methods for establishing a 0.15 to 0.3m thick clay membrane have been tested...... successfully. At natural watercontent w = 40 to 45% it is possible to establish a homogeneous membrane with hydraulic conductivity k tests used for establishing swell and deformation properties showed...... to be very dependent on the stress level. It varies from k = E-11 to 2 E-13 m/s at vertical stresses from 5 to 4800 kPa and is clearly related to a reduced effective porosity diminishing with stress. Preliminary diffusion tests indicate a similar influence on the effective diffusion coefficient being much...

  1. Optimisation of a wet FGD pilot plant using fine limestone and organic acids

    DEFF Research Database (Denmark)

    Frandsen, Jan; Kiil, Søren; Johnsson, Jan Erik

    2001-01-01

    The effects of adding an organic acid or using a limestone with a fine particle size distribution (PSD) have been examined in a wet flue gas desulphurisation (FGD) pilot plant. Optimisation of the plant with respect to the degree of desulphurisation and the residual limestone content of the gypsum......, but the residual limestone content in the gypsum increased to somewhere between 19 and 30 wt%, making this pH range unsuitable for use in a full-scale plant. The investigations have shown that both the addition of organic acids and the use of a limestone with a fine PSD can be used to optimise wet FGD plants. (C...

  2. Coralgal facies of the Upper Eocene-Lower Oligocene limestones in Letca-Rastoci area

    Directory of Open Access Journals (Sweden)

    Ioana Prica

    2001-09-01

    Full Text Available In this paper are described the coralgal facies identified in the Upper Eocene-Lower Oligocene limestone succession (Cozla Formation outcropping in two quarries at Letca and Rastoci (Sălaj district, Romania. In the studied profiles the coral and algae limestones are interlayered with bioclastic limestones with foraminifera. On the top of relatively deep water deposits, coral and algae crusts and dendritic corals coated by algae were deposited. The environment registered a gradual deepening, the deposits being completely immersed, while bioclastic limestones with foraminifera were recurrently formed. This cycle is repeated, the whole succession being caracterized by several such “parasequences”.

  3. Limestone particle size and artificial light for laying hens in the second laying cycle

    Directory of Open Access Journals (Sweden)

    Alexsandro Nunes de Oliveira

    2013-07-01

    Full Text Available The experiment was conducted to evaluate the effects of limestone particle size and the use of artificial light for laying hens in the second laying cycle. We used 240 Hisex White laying hens at 82 weeks of age in a completely randomized design in a 5 × 2 factorial arrangement, resulting in 10 treatments with 4 replicates of 6 birds. The variables were the five particle sizes obtained by increasing the proportion of thick limestone (0, 25, 50, 75 and 100% compared with thin limestone and two lighting programs: with and without artificial light. Limestone particle size and light did not affect performance or egg quality. However, there were changes in bird feeding schedule throughout the day as a response to the lighting program. Bone quality, density and mineral content of the tibia were not affected by the treatments, but limestone particle size had a quadratic effect of on bone deformity and strength, obtaining maximum inclusion points with 63% and 59% of thick limestone, respectively. The use of large particles of limestone in the diet and the use of a lighting program does not influence the performance and quality of the eggs of laying hens in the second production cycle, but the use of a proportion of 63.3 g of average particle size (0.60 mm replacing the fine limestone (0.23 mm per 100 g of total limestone added to the diet improves bone quality in these birds.

  4. The effect of water on the sulphation of limestone

    Energy Technology Data Exchange (ETDEWEB)

    Chunbo Wang; Lufei Jia; Yewen Tan; E.J. Anthony [North China Electric Power University, Baoding City (China). School of Energy and Power Engineering

    2010-09-15

    A series of tests was conducted in a thermogravimetric analyzer (TGA) to study the sulphation behaviour of limestone in the presence of water over the temperature range of 800-850{sup o}C. Four different Canadian limestones, all with a particle size range of 75-425 {mu}m, were sulphated using a synthetic flue gas with a composition of 15% CO{sub 2}, 3% O{sub 2}, 0% or 10% H{sub 2}O, 1750 ppm SO{sub 2} and the balance N{sub 2}. Water was shown to have a significant promotional effect on sulphation, especially in the diffusion-controlled stage. However, the effect of water during the kinetic-controlled stage appeared to be much less pronounced. Based on these results, it is proposed that the presence of water leads to the transient formation of Ca(OH){sub 2} as an intermediate, which in turn reacts with SO{sub 2} at a faster rate than CaO does. Alternatively stated, it appears that H{sub 2}O acts as catalyst for the sulphation reaction of CaO. 30 refs., 8 figs., 3 tabs.

  5. Laser removal of water repellent treatments on limestone

    Science.gov (United States)

    Gómez-Heras, Miguel; Alvarez de Buergo, Mónica; Rebollar, Esther; Oujja, Mohamed; Castillejo, Marta; Fort, Rafael

    2003-12-01

    Protective and water repellent treatments are applied on stone materials used on buildings or sculptures of artistic value to reduce water intrusion without limiting the natural permeability to water vapour of the material. The effect of the wavelength associated with the laser removal of two water repellent treatments applied on limestone, Paraloid B-72, a copolymer of methyl acrylate and ethyl methacrylate, and Tegosivin HL-100, a modified polysiloxane resin, was investigated by using the four harmonics of a Q-switched Nd:YAG laser (1064, 532, 355 and 266 nm). The modifications induced on the surface of limestone samples by laser irradiation were studied using colorimetry, roughness measurements and scanning electron microscopy (SEM). The removal of the treatments was found to be dependent on the laser irradiation conditions and on the characteristics of the coatings. The fundamental laser radiation was effective in removing both treatments, but thermal alteration processes were induced on the constituent calcite crystals. The best results were obtained by irradiation in the near UV at 355 nm.

  6. Laser removal of water repellent treatments on limestone

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Heras, Miguel; Alvarez de Buergo, Monica; Rebollar, Esther; Oujja, Mohamed; Castillejo, Marta; Fort, Rafael

    2003-12-15

    Protective and water repellent treatments are applied on stone materials used on buildings or sculptures of artistic value to reduce water intrusion without limiting the natural permeability to water vapour of the material. The effect of the wavelength associated with the laser removal of two water repellent treatments applied on limestone, Paraloid B-72, a copolymer of methyl acrylate and ethyl methacrylate, and Tegosivin HL-100, a modified polysiloxane resin, was investigated by using the four harmonics of a Q-switched Nd:YAG laser (1064, 532, 355 and 266 nm). The modifications induced on the surface of limestone samples by laser irradiation were studied using colorimetry, roughness measurements and scanning electron microscopy (SEM). The removal of the treatments was found to be dependent on the laser irradiation conditions and on the characteristics of the coatings. The fundamental laser radiation was effective in removing both treatments, but thermal alteration processes were induced on the constituent calcite crystals. The best results were obtained by irradiation in the near UV at 355 nm.

  7. Characterizing and modelling 'ghost-rock' weathered limestones

    Science.gov (United States)

    Dubois, Caroline; Goderniaux, Pascal; Deceuster, John; Poulain, Angélique; Kaufmann, Olivier

    2016-04-01

    'Ghost-rock' karst aquifer has recently been highlighted. In this particular type of aquifer, the karst is not expressed as open conduits but consists in zones where the limestone is weathered. The in-situ weathering of limestone leaves a soft porous material called 'alterite'. The hydro-mechanical properties of this material differs significantly from those of the host rock: the weathering enhances the storage capacity and the conductivity of the rock. This type of weathered karst aquifer has never been studied from a hydrogeological point of view. In this study, we present the hydraulic characterization of such weathered zones. We also present a modelling approach derived from the common Equivalent Porous Medium (EPM) approach, but including the spatial distribution of hydrogeological properties through the weathered features, from the hard rock to the alterite, according to a weathering index. Unlike the Discrete Fracture Network (DFN) approaches, which enable to take into account a limited number of fractures, this new approach allows creating models including thousands of weathered features. As the properties of the alterite have to be considered at a centimeter scale, it is necessary to upscale these properties to carry out simulations over large areas. Therefore, an upscaling method was developed, taking into account the anisotropy of the weathered features. Synthetic models are built, upscaled and different hydrogeological simulations are run to validate the method. This methodology is finally tested on a real case study: the modelling of the dewatering drainage flow of an exploited quarry in a weathered karst aquifer in Belgium.

  8. Hydrogeology of the gray limestone aquifer in southern Florida

    Science.gov (United States)

    Reese, Ronald S.; Cunningham, Kevin J.

    2000-01-01

    Results from 35 new test coreholes and aquifer-test, water-level, and water-quality data were combined with existing hydrogeologic data to define the extent, thickness, hydraulic properties, and degree of confinement of the gray limestone aquifer in southern Florida. This aquifer, previously known to be present only in southeastern Florida (Miami-Dade, Broward, and Palm Beach Counties) below, and to the west of, the Biscayne aquifer, extends over most of central-south Florida, including eastern and central Collier County and southern Hendry County; it is the same as the lower Tamiami aquifer to the north, and it becomes the water-table aquifer and the upper limestone part of the lower Tamiami aquifer to the west. The aquifer generally is composed of gray, shelly, lightly to moderately cemented limestone with abundant shell fragments or carbonate sand, abundant skeletal moldic porosity, and minor quartz sand. The gray limestone aquifer comprises the Ochopee Limestone of the Tamiami Formation, and, in some areas, the uppermost permeable part of an unnamed formation principally composed of quartz sand. Underlying the unnamed formation is the Peace River Formation of the upper Hawthorn Group, the top of which is the base of the surficial aquifer system. Overlying the aquifer and providing confinement in much of the area is the Pinecrest Sand Member of the Tamiami Formation. The thickness of the aquifer is comparatively uniform, generally ranging from 30 to 100 feet. The unnamed formation part of the aquifer is up to 20 feet thick. The Ochopee Limestone accumulated in a carbonate ramp depositional system and contains a heterozoan carbonate-particle association. The principal rock types of the aquifer are pelecypod lime rudstones and floatstones and permeable quartz sands and sandstones. The pore types are mainly intergrain and separate vug (skeletal-moldic) pore spaces. The rock fabric and associated primary and secondary pore spaces combine to form a dual diffuse

  9. Stress-Induced Permeability Alterations in an Argillaceous Limestone

    Science.gov (United States)

    Selvadurai, A. P. S.; Głowacki, A.

    2017-05-01

    The paper presents the results of experiments that were conducted to determine the influence of a triaxial stress state on the evolution of the permeability of an argillaceous limestone. The limestone rock is found in the Ordovician rock formations above the Precambrian basement located in southern Ontario, Canada, which is being considered as a potential host rock for the construction of a deep ground repository for storing low- and intermediate-level nuclear waste. The paper presents the results of an extensive series of hydraulic pulse tests and steady-state tests that were conducted to determine the permeability alterations in zones that can experience levels of damage that can be present in vicinity of an excavated underground opening. A "state-space" relationship is developed to describe permeability evolution with the triaxial stress in the pre-failure regime. The permeability evolution in extensively damaged post-failure states of the rock is also investigated. It is shown that permeability alterations were four orders of magnitude higher as a result of significant damage to the material, which is an important consideration in establishing the efficiency of the host rock formation as a barrier for the long-term containment of radionuclide migration.

  10. Painting with Clay Van Gogh Style.

    Science.gov (United States)

    Skophammer, Karen

    1999-01-01

    Discusses Vincent Van Gogh's painting "Starry Night" and describes a lesson where fifth- and sixth-grade students created their own version of the artwork. Explains that the students utilized four colors of Permoplast clay, using their hands and fingers as brushes and blending tools and the clay as paint. (CMK)

  11. Sectioning Clay Models Makes Anatomy & Development Tangible

    Science.gov (United States)

    Howell, Carina Endres; Howell, James Endres

    2010-01-01

    Clay models have proved to be useful teaching aids for many topics in biology that depend on three-dimensional reasoning. Students studying embryonic development struggle to mentally reconstruct the three-dimensional structure of embryos and larvae by observing prepared slides of cross-sectional slices. Students who build clay models of embryos…

  12. Quick clay and landslides of clayey soils

    NARCIS (Netherlands)

    Khaldoun, A.; Moller, P.; Fall, A.; Wegdam, G.; de Leeuw, B.; Méheust, Y.; Fossum, J.O.; Bonn, D.

    2009-01-01

    We study the rheology of quick clay, an unstable soil responsible for many landslides. We show that above a critical stress the material starts flowing abruptly with a very large viscosity decrease caused by the flow. This leads to avalanche behavior that accounts for the instability of quick clay s

  13. Moessbauer Spectra of Clays and Ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, F. E.; Wagner, U. [Technische Universitaet Muenchen (Germany)

    2004-06-15

    The physical, chemical and mineralogical aspects of the use of Moessbauer spectroscopy in studies of clay-based ceramics are described. Moessbauer spectra of pottery clays fired under oxidising, reducing and changing conditions are explained, and the possibilities of using Moessbauer spectra to derive information on the firing temperatures and the kiln atmosphere during firing in antiquity are discussed and illustrated by examples.

  14. Dehydration-induced luminescence in clay minerals

    Science.gov (United States)

    Coyne, L. M.; Lahav, N.; Lawless, J. G.

    1981-01-01

    Reports of triboluminescent phenomena in organic crystalline materials prompted a search for related processes in clay minerals. The reported extensive mechanical distortion produced on freezing and drying of montmorillonite was particularly interesting because of studies of condensation reactions in a wet/dry cycled reaction sequence. The discovery of an unusual luminescent process in several clay minerals is reported and its characteristics are described.

  15. Colmenar limestone as a resource for built heritage

    Science.gov (United States)

    Fort, Rafael; Álvarez de Buergo, Mónica; Varas-Muriel, MªJosé; Mercedes Pérez-Monserrat, Elena

    2013-04-01

    The Colmenar stone (or Colmenar limestone) has been used in the construction of significant builidings of the Central area of Spain, such as the Royal Palace of Aranjuez (16th -18th centuries) or the Royal Palace of Madrid (18th century). Nowadays this building stone is still widely used, both for new construction and restoration works, as well as for the indoor ornamentation of emblematic buildings such as the Royal Theater of Madrid (20th century). There are many quarries from where this stone was exploited, being the most prestigious ones those located in Colmenar de Oreja, at 50 km Southeast the city of Madrid. The high quality of the stone in these quarries, its whiteness and pureness, made this locality the most relevant in these stonés extractive activities, concentrating the most relevant exploitations and providing the stone the denomination of the municipality (Colmenar). It was an underground mining extraction until the 20th century in order to reach the highest quality level of the mine, the so called "Banco Gordo" (Thick Bank). Generically known as moorland limestone, this rock belongs to the fluvial-lacustrine carbonates of the Upper Miocene Unit of the Tertiary Madrid's Basin. Its tonality mainly ranges from white to cream and even light grey. Under a petrographic point of view, this limestone is constituted by 40% of bioclasts (characea, ostracods and gasteropods), 20-30% of micritic matrix and 30-40% of sparitic cement. Therefore, it can be classified as a biomicrite/biosparite limestone or as a bioclastic packstone. Some particularities of these limestones regarding their appearance are related to some karstic processes they underwent linked to some dissolution phenomena during the Pliocene. All of this resulted on an abundance of cavities with terra rossa fillings, a non-soluble clayey residue, iron enriched, which is the responsible for the reddish and pinkish color that the Colmenar stone sometimes shows. These petrographic characteristics

  16. Distribution of Phosphorus between CaO-CaF2 Slag and Fe-C-P Melt

    Institute of Scientific and Technical Information of China (English)

    WANG Qing-xiang; ZHOU Jian-jian; DU Xiao-jian

    2005-01-01

    The equilibrium distribution ratio of phosphorus between CaO-CaF2 molten slag and Fe-C-P melt at 1450 ℃ was measured. The phosphate capacity of slag and the activity coefficient of phosphorus oxide were calculated.

  17. Thermodynamic simulation of the effect of slag chemistry on the corrosion behavior of alumina-chromia refractory

    Institute of Scientific and Technical Information of China (English)

    Shi-xian Zhao; Bin-li Cai; Hong-gang Sun; Gang Wang; Hong-xia Li; and Xiao-yan Song

    2016-01-01

    The corrosion behavior of alumina–chromia refractory against two kinds of industrial slags (coal slag and iron smelting slag) at 1550°C was investigated via thermodynamic simulations. In the proposed simulation model, the initial slag first attacks the matrix and sur-face aggregates and subsequently attacks the inner aggregates. The simulation results indicate that the slag chemistry strongly affects the phase formation and corrosion behavior of the refractory brick. Greater amounts of alumina were dissolved and spinel solid phases formed when the brick interacted with iron smelting slag. These phenomena, as well as the calculated lower viscosity, may lead to much deeper penetration than that exhibited by coal slag and to more severe corrosion compared to that induced by coal slag. The thermodynamic calcula-tions well match the experimental observations, demonstrating the efficiency of the proposed simulation model for evaluating the corrosion behavior of alumina–chromia refractory.

  18. Geophysical Investigation of Buried Slag at the Parrot Tailings Site, Butte, Montana

    Science.gov (United States)

    Ha, C. D. M.; Shepherd, K.; Mack, A.; Rutherford, B. S.; Speece, M. A.

    2016-12-01

    Butte, Montana, has served as an important mining district for more than 120 years. This area contains historic mine waste from decades of unregulated mining practices. In July 1881, the Parrot smelter in Butte started operations and was soon processing ore and producing copper. The Parrot smelter also had a concentrating plant that treated the ore prior to smelting. The Parrot smelter wastes (slag and tailings) were later covered with Berkeley Pit crushed quartz monzonite overburden. The slag is bricked because it was deposited hot and, as a consequence forms a laterally extensive, cohesive, hard body that is difficult to remove without blasting. With the mine waste being covered by unknown quantities of overburden and soil throughout the area, and core data being limited and expensive to retrieve, the only economical method of discovery is geophysics. Several geophysical techniques were used to determine the lateral boundaries and depth of the buried slag body. The geophysical methods used were seismic, gravity, electromagnetic induction, and magnetics. Not all of these geophysical surveys produced useful results due to the nature of the slag. For instance, electromagnetic induction could not distinguish between the slag and adjacent tailings; and, the microgravity profiles showed only a small gravitational field variation caused by the density contrast between slag and the surrounding tailings, sediment and granitic cover. On the other hand, the seismic surveys resulted in unexpected first arrival times that distinctly showed velocity variations due to the slag. In addition, the slag body produced a large magnetic response. Unpublished, proprietary well data allowed us to model the slag body from our magnetic data. This model was confirmed by projecting velocity tomograms, that we created using seismic diving waves, onto our magnetic models. Model results were combined to form a three-dimensional image of the slag body. These results will be used to help

  19. Active containment systems incorporating modified pillared clays

    Energy Technology Data Exchange (ETDEWEB)

    Lundie, P. [Envirotech (Scotland) Ltd., Aberdeen (United Kingdom)]|[Environmental Resource Industries Disposal Pty Ltd., Perth (Australia); McLeod, N. [Envirotreat Ltd., Kingswinford (United Kingdom)

    1997-12-31

    The application of treatment technologies in active containment systems provides a more advanced and effective method for the remediation of contaminated sites. These treatment technologies can be applied in permeable reactive walls and/or funnel and gate systems. The application of modified pillared clays in active containment systems provides a mechanism for producing permeable reactive walls with versatile properties. These pillared clays are suitably modified to incorporate reactive intercalatants capable of reacting with both a broad range of organic pollutants of varying molecular size, polarity and reactivity. Heavy metals can be removed from contaminated water by conventional ion-exchange and other reactive processes within the clay structure. Complex contamination problems can be addressed by the application of more than one modified clay on a site specific basis. This paper briefly describes the active containment system and the structure/chemistry of the modified pillared clay technology, illustrating potential applications of the in-situ treatment process for contaminated site remediation.

  20. Permeation properties of polymer/clay nanocomposites

    Science.gov (United States)

    Kalendova, A.; Merinska, D.; Gerard, J. F.

    2012-07-01

    The important characteristics of polymer/clay nanocomposites are stability, barrier properties and in the case of polyvinyl chloride also plasticizer migration into other materials. Therefore, the permeation properties of polymer/clay nanocomposites are discussed in this paper. The attention was focused to the polyethylene (PE) and polyvinyl chloride (PVC). Natural type of montmorillonite MMTNa+ and modified types of montmorillonite from Southern Clay Products were used as the inorganic phase. As the compounding machine, one screw Buss KO-kneader was employed. The principal aim is to fully exfoliate the clay into polymer matrix and enhanced the permeation properties. Prepared samples were tested for O2 and CO2 permeability. Polymer/clay nanocomposite structure was determined on the base of X-ray diffraction and electron microscopy (TEM).

  1. Clay Dispersibility and Soil Friability-Testing the Soil Clay-to-Carbon Saturation Concept

    DEFF Research Database (Denmark)

    Schjønning, Per; de Jonge, Lis Wollesen; Munkholm, Lars Juhl;

    2012-01-01

    Soil organic carbon (OC) influences clay dispersibility, which affects soil tilth conditions and the risk of vertical migration of clay colloids. No universal lower threshold of OC has been identified for satisfactory stabilization of soil structure. We tested the concept of clay saturation with OC...... as a predictor of clay dispersibility and soil friability. Soil was sampled 3 yr in a field varying in clay content (∼100 to ∼220 g kg−1 soil) and grown with different crop rotations. Clay dispersibility was measured after end-over-end shaking of field-moist soil and 1- to 2-mm sized aggregates either air......-dried or rewetted to −100 hPa matric potential. Tensile strength of 1- to 2-, 2- to 4-, 4- to 8-, and 8- to 16-mm air-dried aggregates was calculated from their compressive strength, and soil friability estimated from the strength–volume relation. Crop rotation characteristics gave only minor effects on clay...

  2. Performance analysis of alumina slag from smelting furnace of vanadium iron%钒铁冶炼炉氧化铝渣的性能分析

    Institute of Scientific and Technical Information of China (English)

    吴胜利

    2014-01-01

    为了探索钒铁冶炼炉氧化铝渣用于耐火材料的可能性,选取完整的氧化铝渣渣饼,剖开后根据其断面不同区域的颜色和致密度分层取样,检测其理化性能、物相组成、颗粒(5~3 mm)强度及水硬特性。试验结果表明:氧化铝渣饼大致可分为三层:以MgO为主要成分(质量分数为83.89%)的镁砂层,以镁铝尖晶石、方镁石和二铝酸一钙为主晶相的变质层,以二铝酸一钙和镁铝尖晶石为主晶相(二者的体积分数之和在80%以上)的主渣层;各渣层的耐火度大于1790℃,体积密度大于3.0 g·cm-3,吸水率≤2.4%;主渣层的颗粒强度与焦宝石的接近,具有水硬性。综合来看,氧化铝渣可用于耐火材料。%To explore the possibility of using alumina slag from smelting furnace of vanadium iron to produce refractories,a full piece of alumina slag cake was selected,and stratified sampled according to the color and density of cross sections in different regions.The chemical compositions and physical properties, phase compositions,particles (5 -3 mm)strength and hydraulic properties were tested.The results show that:(1)the alumina slag cake can be broadly divided into three layers:a magnesite layer with MgO as the main composition (MgO 83.89 mass%),a degenerative layer with magnesium aluminate spinel,periclase and calcium dialuminate as main phases,and a main slag layer with calcium dialuminate and magnesium aluminate spinel as main phases (volume fraction of the two phases ≥80%);(2)the refractoriness of all slag layers is higher than 1 790 ℃,the BD is higher than 3.0 g·cm -3 and the water absorption is lower than 3.0%,the particle strength in the main slag layer is close to that of flint clay possessing hydraulic properties;(3)to sum up,the alumina slag from smelting furnace of vanadium iron can be used in refracto-ries production.

  3. Experimental Study on Optimum Mix Ratio of Blast-Furnace Slag and Fly Ash for Clayey Soil Improvement%高炉矿渣粉煤灰联合处理黏性土最佳配合比试验

    Institute of Scientific and Technical Information of China (English)

    李伟; 赵燕; 刘玉珂

    2013-01-01

    目的 研究高炉矿渣、粉煤灰与黏性土混合土材料的力学特性,提出混合料的最佳配合比,为高炉矿渣、粉煤灰在软土地基处理中的应用提供理论依据.方法 利用应变控制式三轴剪切渗透试验仪,对不同配合比的高炉矿渣、粉煤灰、黏性土的试件进行不同龄期和围压下的不排水、不固结三轴压缩试验.结果 混合料的主应力差、割线弹性模量随着配合比的增加出现了先增大后减小的抛物线规律.当高炉矿渣和粉煤灰配合比含量在2:8~3:7时,主应力差和割线弹性模量达到最大值.结论高炉矿渣和粉煤灰联合对黏性土进行处理,可有效地提高地基承载力,降低基础沉降量.%Through the research of the mechanical properties of the blast furnace slag,fly ash and clay mixed soil material,we can find out the optimum mix ratio. And it will provide a theoretical basis for applying the blast furnace slag,fly ash on soft ground. The method is to do the unconsolidated-undrained triaxial compression test on the samples which have different mix proportion of blast furnace slag,fly ash and clay mixed soil material with different age and different confining pressure by using strain controlled triaxial shear penetration tester. With the increase in the ratio,the principal stress difference and secant modulus of elasticity of mixture appeared the Parabolic law which first increased and then decreased. When the content of blast furnace slag and fly ash is between 2:8 and 3:7, the principal stress difference and secant elastic modulus reached a maximum. The processing of clayey soil by blast furnace slag and fly ash can effectively improve the bearing capacity foundation and reduce the foundation settlement.

  4. Mineralogy and geotechnical characteristics of some pottery clay

    OpenAIRE

    Mujib Olamide ADEAGBO; Samuel Akinlabi OLA; Olumide Oluwapelumi OJURI

    2016-01-01

    The physical properties of soils, which are tremendously influenced by the active clay minerals in soil, are of great importance in geotechnical engineering. This paper investigates the clay-sized particles of the Igbara-Odo pottery clay, and compares results obtained with available data on the bulk sample, to determine their correlation and underline the dependence of the geotechnical properties of the bulk clay material on the clay-sized particles. The bulk clay sample consists of 52% sand-...

  5. Analysis Of Separation Mechanism Of The Metallic Phase Of Slag In The Direct-To-Blister Process

    Directory of Open Access Journals (Sweden)

    Bydałek A.W.

    2015-09-01

    Full Text Available The article discusses the structure of the slag in the liquid state, the properties and interactions within the slag. The analysis of structures occurring in slag suspension were presented with regard to differences in chemical composition in micro-areas. Two different mechanisms for formation of precipitates in Cu-Fe-Pb alloys during extraction were showed.

  6. Utilization of lightweight materials made from coal gasification slags. Quarterly report, December 1, 1995--February 28, 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    The project scope consists of collecting a 20-ton sample of slag (primary slag), processing it for chart removal, and subjecting it to pyroprocessing to produce expanded slag aggregates of various size gradations and unit weights, ranging from 12 to 50 lb/fg{sup 3}. A second smaller slag sample will be used for confirmatory testing. The expanded slag aggregates will then be tested for their suitability in manufacturing precast concrete products (e.g., masonry blocks and roof tiles) and insulating concrete, first at the laboratory scale and subsequently in commercial manufacturing plants. These products will be evaluated using ASTM and industry test methods. Technical data generated during production and testing of the products will be used to assess the overall technical viability of expanded slag production. In addition, a market assessment will be made based on an evaluation of both the expanded slag aggregates and the final products, and market prices for these products will be established in order to assess the economic viability of these utilization technologies. Relevant cost data for physical and pyroprocessing of slag to produce expanded slag aggregates will be gathered for comparison with (1) the management and disposal costs for slag or similar wastes and (2) production costs for conventional materials which the slag aggregates would replace. This will form the basis for an overall economic evaluation of expanded slag utilization technologies.

  7. Crystallographic transformation of limestone during calcination under CO2.

    Science.gov (United States)

    Valverde, Jose Manuel; Medina, Santiago

    2015-09-14

    The calcination reaction of limestone (CaCO3) to yield lime (CaO) is at the heart of many industrial applications as well as natural processes. In the recently emerged calcium-looping technology, CO2 capture is accomplished by the carbonation of CaO in a gas-solid reactor (carbonator). CaO is derived by the calcination of limestone in a calciner reactor under necessarily high CO2 partial pressure and high temperature. In situ X-ray diffraction (XRD) has been employed in this work to gain further insight into the crystallographic transformation that takes place during the calcination of limestone under CO2, at partial pressures (P) close to the equilibrium pressure (Peq) and at high temperature. Calcination under these conditions becomes extremely slow. The in situ XRD analysis presented here suggests the presence of an intermediate metastable CaO* phase stemming from the parent CaCO3 structure. According to the reaction mechanism proposed elsewhere, the exothermicity of the CaO* → CaO transformation and high values of P/Peq inhibit the nucleation of CaO at high temperatures. The wt% of CaO* remains at a relatively high level during slow calcination. Two diverse stages have been identified in the evolution of CaO crystallite size, L. Initially, L increases with CaCO3 conversion, following a logarithmic law. Slow calcination allows the crystallite size to grow up from a few nanometers at nucleation up to around 100 nm near the end of conversion. Otherwise, quick calcination at relatively lower CO2 concentrations limits CaO crystallite growth. Once calcination reaches an advanced state, the presence of CaO* drops to zero and the rate of increase of the CaO crystallite size is significantly hindered. Arguably, the first stage in CaO crystallite growth is driven by aggregation of the metastable CaO* nanocrystals, due to surface attractive forces, whereas the second one is consistent with sintering of the aggregated CaO crystals, and persists with time after full

  8. Study of Phase Relations of ZnO-Containing Fayalite Slag Under Fe Saturation

    Science.gov (United States)

    Shi, Huayue; Chen, Liugang; Malfliet, Annelies; Jones, Peter Tom; Blanpain, Bart; Guo, Muxing

    2016-10-01

    A ZnO-containing fayalite-based slag can be formed in copper smelting from secondary raw materials and its high viscosity is a common issue that hinders slag tapping. In this work, the crystallization behavior of the industrial slag was observed in situ by confocal laser scanning microscopy. Solid precipitation was found to be the major cause of the poor slag fluidity. The phase relations in the industrial slag system ZnO-"FeO"-SiO2-Al2O3-CaO (CaO/SiO2 = 0.05, Al2O3/SiO2 = 0.15) were investigated by quenching the samples after reaching equilibrium at 1423 K (1150 °C) under iron saturation. The equilibrium composition of the phases was determined with electron probe micro-analysis. The effect of individual components, such as FeO, ZnO, and CaO on the phase equilibrium of the slag system has been quantitatively studied. The relation between the solid-phase fraction and the chemical composition of the slag has been revealed. Suggestions to modify the slag composition toward low viscosity are provided.

  9. Physico-chemical characterization of steel slag. Study of its behavior under simulated environmental conditions.

    Science.gov (United States)

    Navarro, Carla; Díaz, Mario; Villa-García, María A

    2010-07-15

    The chemical and mineralogical composition of steel slag produced in two ArcelorMittal steel plants located in the North of Spain, as well as the study of the influence of simulated environmental conditions on the properties of the slag stored in disposal areas, was carried out by elemental chemical analysis, XRF, X-ray diffraction, thermal analysis, and scanning electron microscopy with EDS analyzer. Spectroscopic characterization of the slag was also performed by using FTIR spectroscopy. Due to the potential uses of the slag as low cost adsorbent for water treatment and pollutants removal, its detailed textural characterization was carried out by nitrogen adsorption-desorption at 77 K and mercury intrusion porosimetry. The results show that the slag is a crystalline heterogeneous material whose main components are iron oxides, calcium (magnesium) compounds (hydroxide, oxide, silicates, and carbonate), elemental iron, and quartz. The slags are porous materials with specific surface area of 11 m(2)g(-1), containing both mesopores and macropores. Slag exposure to simulated environmental conditions lead to the formation of carbonate phases. Carbonation reduces the leaching of alkaline earth elements as well as the release of the harmful trace elements Cr (VI) and V. Steel slags with high contents of portlandite and calcium silicates are potential raw materials for CO(2) long-term storage.

  10. Superconducting magnetic separation of ground steel slag powder for recovery of resources

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, H. W.; Kim, J. J.; Kim, Young Hun [Andong National University, Andong (Korea, Republic of); Ha, D. W. [Korea Electrotechnology Research Institute, Changwon (Korea, Republic of); Choi, J. H. [Dept. of Environmental Engineering, Catholic University of Pusan, Pusan (Korea, Republic of)

    2017-03-15

    Steel slag has been considered as an industrial waste. A huge amount of slag is produced as a byproduct and the steel slag usually has been dumped in a landfill site. However the steel slag contains valuable resources such as iron, copper, manganese, and magnesium. Superconducting magnetic separation has been applied on recovery of the valuable resources from the steel slag and this process also has intended to reduce the waste to be dumped. Cryo-cooled Nb-Ti superconducting magnet with 100 mm bore and 600 mm of height was used as the magnetic separator. The separating efficiency was evaluated in the function of magnetic field. A steel slag was ground and analyzed for the composition. Iron containing minerals were successfully concentrated from less iron containing portion. The separation efficiency was highly dependent on the particle size giving higher separating efficiency with finer particle. The magnetic field also effects on the separation ratio. Current study showed that an appropriate grinding of slag and magnetic separation lead to the recovery of metal resources from steel slag waste rather than dumping all of the volume.

  11. Substrate pH and butterfly bush response to dolomitic lime or steel slag amendment

    Science.gov (United States)

    Steel slag is a fertilizer amendment with a high concentration of calcium oxide, and thus capable of raising substrate pH similar to dolomitic lime. Steel slag, however, contains higher concentrations of some nutrients, such as iron, manganese, and silicon, compared to dolomitic lime. The objectiv...

  12. Novel Approach for Modeling of Nonuniform Slag Layers and Air Gap in Continuous Casting Mold

    Science.gov (United States)

    Wang, Xudong; Kong, Lingwei; Yao, Man; Zhang, Xiaobing

    2017-02-01

    Various kinds of surface defects on the continuous casting slab usually originate from nonuniform heat transfer and mechanical behavior, especially during the initial solidification inside the mold. In this article, a model-coupled inverse heat transfer problem incorporating the effect of slag layers and air gap is developed to study the nonuniform distribution of liquid slag, solid slag, and air gap layers. The model considers not only the formation and evolution of slag layers and air gap but also the temperatures in the mold copper as measured by thermocouples. The simulation results from the model and the measured temperatures from experiments are shown to be in good agreement with each other. At the casting speed of 0.65 m/min, the liquid slag film disappears and transforms into solid slag entirely at about 400 mm away from meniscus, and an air gap begins to form. Until the mold exit, the maximum thickness of the solid slag layer and air gap gradually increases to 1.34 and 0.056 mm, respectively. The results illustrate that the magnitude and nonuniform distribution of the slag layers and air gap along the cross direction, correlating with heat flux between the shell and mold, eventually determine the temperature profiles of the mold hot face and slab surface. The proposed model may provide a convenient approach for analyzing nonuniform heat transfer and mechanical behaviors between the mold and slab in the real casting process.

  13. Heavy metal adsorption changes of EAF steel slag after phosphorus adsorption.

    Science.gov (United States)

    Song, Guanling; Cao, Lijing; Chen, Xiao; Hou, Wenhua; Wang, Qunhui

    2012-01-01

    A kind of electric arc furnace (EAF) steel slag was phosphated, and its isothermal and dynamic adsorptions of copper, cadmium, and lead ions were measured to determine if heavy metal adsorption changes after phosphorus adsorption. The surface area increased greatly after the slag was phosphated. Isothermal adsorption experiments showed that the theoretical Q(max) of the EAF steel slag on Cu(2+), Cd(2+), and Pb(2+) improved 59, 50, and 89% respectively after it was phosphated. Dynamic adsorption results showed that the greatest adsorption capacities of unit volume of Cu(2+), Cd(2+), and Pb(2+) were 2.2, 1.8, and 1.8 times that of the column packed with original EAF steel slag when the column was packed with phosphate EAF steel slag at the same heavy metal ion concentration. The breakthrough time, the exhaustion time and elution efficiency of the column also increased when the column was packed with phosphated EAF steel slag compared with that packed with original EAF steel slag. Phosphorus adsorption could further improve the heavy metal ion adsorption of the EAF steel slag.

  14. Behaviour of fibre reinforced concrete using steel slag coarse aggregate produced in Qatar

    Directory of Open Access Journals (Sweden)

    Alnahhal Wael

    2017-01-01

    Full Text Available The state of Qatar suffers from the shortage of natural resources needed for concrete production. Therefore, it is essential to investigate the feasibility of using by-product recycled materials as aggregates to maintain the concrete construction industry. Several types of recyclable materials are currently used in concrete. One of the potential resources of recycled concrete is steel slag. Knowing that Steel slag is the most significant solid waste generated by Qatar Steel Company in Qatar, replacing of natural coarse aggregate with steel slag aggregate will have a significant environmental and economic impact to the state of Qatar. This paper presents the compression and flexural test results of different concrete mixes made of steel slag coarse aggregate combined with a newly developed basalt chopped fibres. The parameters investigated included the volume fraction of the fibre used and the type of coarse aggregates (natural aggregates “Gabbro” and steel slag aggregates. Plain concrete specimens containing natural coarse aggregates and steel slag aggregates with no fibres added were also tested to serve as control. Test results showed that adding the basalt chopped fibres to the concrete mixes enhanced their flexural tensile strengths at different percentages. In addition, the compressive strength of concrete made with steel slag aggregate was higher than that made with natural gabbro aggregate. Test results clearly showed that steel slag aggregates can be used as sustainable and eco-friendly alternative materials in concrete structures.

  15. The Effect of Solid Constituent Particle Size Distributions on TP-H1148 Propellant Slag

    Science.gov (United States)

    May, Douglas H.; Miles, William L.; Taylor, David S.; Rackham, Jon L.

    1997-01-01

    Special aluminum and ammonium perchlorate (AP) particle size distributions were prepared for a matrix of five-inch diameter, center-perforated (CP) motor tests to measure the aluminum oxide slag response in Space Shuttle Reusable Solid Rocket Motor (RSRM) propellant. Previous tests of TP-H1148 propellant in five-inch CP spin motors have shown a correlation between aluminum particle size and generated slag. The motors for this study were cast from thirteen five-gallon propellant mixes which used five particle size levels of aluminum powder, five of unground AP and three of ground AP. Aluminum had the greatest effect on slag formation, the more coarse fractions causing greater slag quantities and larger slag particles. Unground AP had about half the effect of aluminum with the coarser fractions again producing more and larger sized slag particles. The variation in ground AP did not have a significant effect on slag formation. Quench bomb tests showed the same trends as the spin motors, that is, larger aluminum and AP particle size distributions generated larger slag particles leaving the propellant surface. Cured propellant mechanical properties were also impacted by particle size variation.

  16. Slag optimization in charcoal blast furnaces; Otimizacao de escorias de altos-fornos a carvao vegetal

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Luiz Fernando Andrade de; Tavares, Roberto Parreiras; Figueira, Renato Minelli; Lopes, Leonardo Braga Polido; Goncalves, Alexandre Ferreira [Associacao Brasileira de Metais (ABM), Sao Paulo, SP (Brazil)

    1987-12-31

    In this work, it is shown the optimum composition of charcoal blast furnace slag using phase diagrams. The results are compared with industrial data and some possible changes in slag composition and mass are also suggested. (author) 3 refs., 5 figs., 3 tabs.

  17. Heat Recovery from High Temperature Slags: A Review of Chemical Methods

    Directory of Open Access Journals (Sweden)

    Yongqi Sun

    2015-03-01

    Full Text Available Waste heat recovery from high temperature slags represents the latest potential way to remarkably reduce the energy consumption and CO2 emissions of the steel industry. The molten slags, in the temperature range of 1723–1923 K, carry large amounts of high quality energy. However, the heat recovery from slags faces several fundamental challenges, including their low thermal conductivity, inside crystallization, and discontinuous availability. During past decades, various chemical methods have been exploited and performed including methane reforming, coal and biomass gasification, and direct compositional modification and utilization of slags. These methods effectively meet the challenges mentioned before and help integrate the steel industry with other industrial sectors. During the heat recovery using chemical methods, slags can act as not only heat carriers but also as catalysts and reactants, which expands the field of utilization of slags. Fuel gas production using the waste heat accounts for the main R&D trend, through which the thermal heat in the slag could be transformed into high quality chemical energy in the fuel gas. Moreover, these chemical methods should be extended to an industrial scale to realize their commercial application, which is the only way by which the substantial energy in the slags could be extracted, i.e., amounting to 16 million tons of standard coal in China.

  18. Characterization and activation of the slag of El Hadjar's blast furnaces by clinkers

    Energy Technology Data Exchange (ETDEWEB)

    Guetteche, M.N.; Houari, H. [Constantine Univ. (France)

    2001-07-01

    The El Hadjar steel plant in Algeria produces about 430,000 tons of slag annually. This paper presents a study in which the granular slag of El Hadjar's blast furnace was characterized using a variety of analytical methods that made it possible to calculate hydraulic indices. El Hadjar slag is being promoted in the construction industry in an effort to address environmental concerns regarding the production of portland cement which is very energy intensive and which contributes to major greenhouse gas emissions into the atmosphere. The use of slag as an addition to portland cement or the manufacturing of clinker free binder would make this waste into a valuable product. Chemical analysis, x-ray diffraction, differential thermal analysis, Fourier transformer infrared spectrometry and conductimetry were used to better understand the vitreous structure of the slag and its hydraulic reactivity. Prismatic test tubes were used for the mechanical tests which involved clinkers of various grinding rates of slag. The results showed that slag is reactive and that the evolution of mechanical resistance to grinding is very sensitive. It was also shown that long term mechanical performance of the slag based ingredients are of significant interest to the cement and concrete industry. 9 refs., 9 tabs., 5 figs.

  19. Microstructure and Composition of Hydration Products of Ordinary Portland Cement with Ground Steel-making Slag

    Institute of Scientific and Technical Information of China (English)

    LI Yong-xin; CHEN Yi-min; ZHANG Hong-tao; HE Xing-yang; WEI Jiang-xiong; ZHANG Wen-sheng

    2003-01-01

    The effect of ground steel-making slag on microstructure and composition of hydration products of ordinary Portland cement (OPC) was investigated by mercury intrusion porosimetry ( MIP ), X- ray diffraction (XRD) and differential thermal analysis (DTA). Results show that ground steel-making slag is a kind of high activity mineral additives and it can raise the longer-age strength of OPC mortar. The total porosity and average pore diameter of OPC paste with groand steel-making slag increase with the increase of the amount of ground steelmaking slag replacing OPC at various ages, while after 28 days most pores in OPC paste with ground steel-making slag do not influeace the strength because the diameter of those pores is in the rang of 20 to 50nm. The hydration mechanism of ground steel-making slag is similar to that of OPC but different from that of fly ash and blast furnace slag. The hydration products of ground steel-making slag contain quite a lot of Ca( OH)2 in long age.

  20. Removal kinetics of phosphorus from synthetic wastewater using basic oxygen furnace slag.

    Science.gov (United States)

    Han, Chong; Wang, Zhen; Yang, He; Xue, Xiangxin

    2015-04-01

    Removal kinetics of phosphorus through use of basic oxygen furnace slag (BOF-slag) was investigated through batch experiments. Effects of several parameters such as initial phosphorus concentration, temperature, BOF-slag size, initial pH, and BOF-slag dosage on phosphorus removal kinetics were measured in detail. It was demonstrated that the removal process of phosphorus through BOF-slag followed pseudo-first-order reaction kinetics. The apparent rate constant (kobs) significantly decreased with increasing initial phosphorus concentration, BOF-slag size, and initial pH, whereas it exhibited an opposite trend with increasing reaction temperature and BOF-slag dosage. A linear dependence of kobs on total removed phosphorus (TRP) was established with kobs=(3.51±0.11)×10(-4)×TRP. Finally, it was suggested that the Langmuir-Rideal (L-R) or Langmuir-Hinshelwood (L-H) mechanism may be used to describe the removal process of phosphorus using BOF-slag.