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Sample records for cement clinker production

  1. By-product materials in cement clinker manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Gadayev, A. [ICS and E, Aurora, CO (United States); Kodess, B. [VNIIMS Gosstandart of Russia, Moscow (Russian Federation)

    1999-02-01

    The use of Cl- and SO{sub 3}-containing by-products from chemical industries for manufacturing Portland cement clinker using a wet process was examined. The chemical and mineralogical compositions of the by-products and raw materials were determined. Homogeneous raw mixes containing different concentrations of by-products (5--30%) were prepared and the influence of the by-products on all steps of burning the mixes in a kiln to form a cement clinker was investigated. It was shown that introducing Cl- and SO{sub 3}-containing by-products to the raw mixes significantly changes all the cement clinker producing stages and changes the chemical and mineralogical compositions at all intermediate stages and in the finished products, forming new minerals containing Cl and SO{sub 3} [CaO{sub x} (SiO{sub 2}){sub y} CaCl{sub 2}] or [CaO{sub x} (SiO{sub 2}){sub y} CaSO{sub 4}] and increasing the amount of well-known intermediate minerals. The presence of the chlorides and sulfates in the cement clinker burning processes removes alkali from the raw mixes, turning them to volatile forms, accelerating the raw mineral decomposition processes and accelerating the formation processes of cement minerals (C{sub 2}S, C{sub 12}A{sub 7}, C{sub 4}AF) and formation of chloride and sulfate cycles in the kiln, forming clinker liquids and decreasing the formation and growth of the main cement minerals (C{sub 3}A, C{sub 3}S). The cement clinker contains some quantity of minerals with Cl or SO{sub 3}. Their presence in the final product decreases cement quality by reducing the amount of active CaO (C) and reducing the active CaO/SiO{sub 2} ratio.

  2. Comparative Characterization of Clinker's Microstructure at Different Temperature Zone during Cement Production

    OpenAIRE

    Mohd S. Idris; Khairul N. Ismail; Shamsul B. Jamaludin; Che M.R. Ghazali; Kamarudin Hussin

    2007-01-01

    Temperature is an important parameter for transformation of minerals in clinker during cement productions. It influences the formation of alite from belite during calcinations and clinkering processes. The result of microstructure shows that the formation of belite minerals started at temperature nearly 1200oC which is at calcinations zone temperature, followed by formation of α-belite at higher temperature (around 1300oC), then formation of β-belite and finally, with the suitable c...

  3. Cements with low Clinker Content

    Science.gov (United States)

    García-Lodeiro, I.; Fernández-Jiménez, A.; Palomo, A.

    2015-11-01

    Hybrid alkaline cements are multi-component systems containing a high percentage of mineral additions (fly ash, blast furnace slag), low proportions (clinker and scarce amounts of alkaline activators. The substantially lower amount of clinker needed to manufacture these binders in comparison to ordinary Portland cement is both economically and ecologically beneficial. Their enormous versatility in terms of the raw materials used has made them the object of considerable interest. The present study explored the mechanical strength of binary blends mixes; B1= 20% clinker (CK) + 80% fly ash (FA) and B2=20% clinker + 80% blast furnace slag (BFS), both hydrated in the presence and absence of an alkaline activator specifically designed for this purpose. The use of the activator enhanced the development of early age strength considerably. All the hydrated matrices were characterised with XRD, SEM/EDX and (29Si and 27Al) NMR. The use of the alkaline activator generated reaction products consisting primarily of a mix of gels ((N,C)-A-S-H and C-A-S-H) whose respective proportions were found to depend upon system composition and initial reactivity.

  4. Phase chemistry in process models for cement clinker and lime production

    OpenAIRE

    2014-01-01

    The goal of the thesis is to evaluate if developed phase chemical process models for cement clinker and lime production processes are reliable to use as predictive tools in understanding the changes when introducing sustainability measures. The thesis describes the development of process simulation models in the application of sustainability measures as well as the evaluation of these models. The motivation for developing these types of models arises from the need to predict the chemical and ...

  5. Chromium behavior during cement-production processes: A clinkerization, hydration, and leaching study

    Energy Technology Data Exchange (ETDEWEB)

    Sinyoung, Suthatip [Department of Environmental Engineering, Faculty of Engineering, King Mongkut' s University of Technology Thonburi, Bangkok, 10140 (Thailand); Songsiriritthigul, Prayoon [Synchrotron Light Research Institute, PO Box 93 Nakhon Ratchasima, 30000 (Thailand); School of Physics, Suranaree University of Technology, Nakhon Ratchasima, 30000 (Thailand); Asavapisit, Suwimol, E-mail: suwimol_s@hotmail.com [Environmental Technology, School of Energy and Materials, King Mongkut' s University of Technology Thonburi, Bangkok, 10140 (Thailand); National Center of Excellence for Environmental and Hazardous Waste Management, Faculty of Engineering, King Mongkut' s University of Technology Thonburi, Bangkok, 10140 (Thailand); Kajitvichyanukul, Puangrat, E-mail: puangratk@nu.ac.th [National Center of Excellence for Environmental and Hazardous Waste Management, Faculty of Engineering, King Mongkut' s University of Technology Thonburi, Bangkok, 10140 (Thailand); Department of Civil Engineering, Faculty of Engineering, Naresuan University, Phitsanulok, 65000 (Thailand)

    2011-07-15

    Highlights: {yields} Behavior of chromium during cement-production processes. {yields} Formation of new chromium compounds in clinker with chromium oxidation states of +3, +4.6, +5, and +6. {yields} Addition of chromium altered the composition of the clinker phases, setting time, and compressive strength of hydrated mixes. {yields} Cr{sup 3+} and Cr{sup 6} were leached during leaching tests, whereas other species remained in the mortar. - Abstract: The behavior of chromium during the production of cement clinker, during the hydration of cement and during the leaching of cement mortars was investigated. The microstructures of clinker and mortar properties were investigated using free lime, XRD, SEM/EDS, and TG/DTA techniques. Chromium was found to be incorporated in the clinker phase. The formation of new chromium compounds such as Ca{sub 6}Al{sub 4}Cr{sub 2}O{sub 15}, Ca{sub 5}Cr{sub 3}O{sub 12}, Ca{sub 5}Cr{sub 2}SiO{sub 12}, and CaCr{sub 2}O{sub 7}, with chromium oxidation states of +3, +4.6, +5, and +6, respectively, was detected. After the hydration process, additional chromium compounds were identified in the mortar matrix, including Ca{sub 5}(CrO{sub 4}){sub 3}OH, CaCrO{sub 4}.2H{sub 2}O, and Al{sub 2}(OH){sub 4}CrO{sub 4}, with chromium oxidation states of +4.6, +6, and +6, respectively. Additionally, some species of chromium, such as Cr{sup 3+} from Ca{sub 6}Al{sub 4}Cr{sub 2}O{sub 15} and Cr{sup 6+} from CaCr{sub 2}O{sub 7}, CaCrO{sub 4}.2H{sub 2}O, and Al{sub 2}(OH){sub 4}CrO{sub 4}, were leached during leaching tests, whereas other species remained in the mortar. The concentrations of chromium that leached from the mortar following U.S. EPA Method 1311 and EA NEN 7375:2004 leaching tests were higher than limits set by the U.S. EPA and the Environment Agency of England and Wales related to hazardous waste disposal in landfills. Thus, waste containing chromium should not be allowed to mix with raw materials in the cement manufacturing process.

  6. Chromium behavior during cement-production processes: a clinkerization, hydration, and leaching study.

    Science.gov (United States)

    Sinyoung, Suthatip; Songsiriritthigul, Prayoon; Asavapisit, Suwimol; Kajitvichyanukul, Puangrat

    2011-07-15

    The behavior of chromium during the production of cement clinker, during the hydration of cement and during the leaching of cement mortars was investigated. The microstructures of clinker and mortar properties were investigated using free lime, XRD, SEM/EDS, and TG/DTA techniques. Chromium was found to be incorporated in the clinker phase. The formation of new chromium compounds such as Ca(6)Al(4)Cr(2)O(15), Ca(5)Cr(3)O(12), Ca(5)Cr(2)SiO(12), and CaCr(2)O(7), with chromium oxidation states of +3, +4.6, +5, and +6, respectively, was detected. After the hydration process, additional chromium compounds were identified in the mortar matrix, including Ca(5)(CrO(4))(3)OH, CaCrO(4)·2H(2)O, and Al(2)(OH)(4)CrO(4), with chromium oxidation states of +4.6, +6, and +6, respectively. Additionally, some species of chromium, such as Cr(3+) from Ca(6)Al(4)Cr(2)O(15) and Cr(6+) from CaCr(2)O(7), CaCrO(4)·2H(2)O, and Al(2)(OH)(4)CrO(4), were leached during leaching tests, whereas other species remained in the mortar. The concentrations of chromium that leached from the mortar following U.S. EPA Method 1311 and EA NEN 7375:2004 leaching tests were higher than limits set by the U.S. EPA and the Environment Agency of England and Wales related to hazardous waste disposal in landfills. Thus, waste containing chromium should not be allowed to mix with raw materials in the cement manufacturing process.

  7. Utilization of municipal solid waste incineration fly ash for sulfoaluminate cement clinker production.

    Science.gov (United States)

    Wu, Kai; Shi, Huisheng; Guo, Xiaolu

    2011-01-01

    The feasibility of partially substituting raw materials with municipal solid waste incineration (MSWI) fly ash in sulfoaluminate cement (SAC) clinker production was investigated by X-ray diffraction (XRD), compressive strength and free expansion ratio testing. Three different leaching tests were used to assess the environmental impact of the produced material. Experimental results show that the replacement of MSWI fly ash could be taken up to 30% in the raw mixes. The good quality SAC clinkers are obtained by controlling the compositional parameters at alkalinity modulus (C(m)) around 1.05, alumina-sulfur ratio (P) around 2.5, alumina-silica ratio (N) around 2.0~3.0 and firing the raw mixes at 1250 °C for 2h. The compressive strengths of SAC are high in early age while that develop slowly in later age. Results also show that the expansive properties of SAC are strongly depended on the gypsum content. Leaching studies of toxic elements in the hydrated SAC-based system reveal that all the investigated elements are well bounded in the clinker minerals or immobilized by the hydration products. Although some limited positive results indicate that the SAC prepared from MSWI fly ash would present no immediate thread to the environment, the long-term toxicity leaching behavior needs to be further studied.

  8. ECO-EFFICIENCY ANALYSIS OF LOW-CARBON CEMENT PRODUCTION BY REPLACING CLINKER

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    Yanay Ruíz Rosa

    2017-04-01

    Full Text Available This work carries out the environmental evaluation of the cement production in Siguaney Factory as well as the calculation of the Eco-efficiency indicators according to the ISO 14045 norms; the Recipe methodology was used including 18 impact categories and the SimaPro 8.1 software was also used. In order to evaluate the eco-efficiency indicators according to the ISO 14045 norm, the results of the impact categories are related to the monetary value indicators, allowing the evaluation of the current situation as well as the consequences of the suggested modifications. As a result, the environmental profiles of P-35 cement (base case were obtained as well as those of the low carbon ones (LC3-35 y LC3-50 resulting from the clinker substitution by kaolinitic clay after some studies carried out by CIDEM researchers; and the eco-efficiency profiles. The comparison made between P-35 cement and the low-carbon cements showed positive results in eight weather impact categories, however, toxicity-related ones rise due to the increase in electricity consumption connected to the grinding of materials to obtain burnt clay bringing about a greater amount of emissions of volatile organic compounds to the air. An improvement in the eco-efficiency of 6 out of 8 calculated indicators is observed due to a simultaneous decrease in the production costs and the environmental impacts. LC3-50 cement shows the best results. The methodology used permits to evaluate alternatives related to the material substitution in the construction sector.

  9. USE OF CONSTRUCTION AND DEMOLITION WASTES AS RAW MATERIALS IN CEMENT CLINKER PRODUCTION

    Institute of Scientific and Technical Information of China (English)

    Christos-Triantafyllos Galbenis; Stamatis Tsimas

    2006-01-01

    The aim of the present paper was to investigate the possibility of utilizing Construction and Demolition(C&D) wastes as substitutes of Portland cement raw meal. The C&D wastes that were so used, were the Recycled Concrete Aggregates (RCA) and the Recycled Masonry Aggregates (RMA) derived from demolished buildings in Attica region, Greece. RCA and RMA samples were selected because of their calcareous and siliceous origin respectively,which conformed the composition of the ordinary Portland cement raw meal. For that reason, six samples of cement raw meals were prepared: one with ordinary raw materials, as a reference sample, and five by mixing the reference sample with RCA and RMA in appropriate proportions. The effect on the reactivity of the generated mixtures, was evaluated on the basis of the free lime content (fCaO) in the mixtures sintered at 1350℃, 1400℃ and 1450℃. Test showed that the added recycled aggregates improved the burnability of the cement raw meal without affecting negatively the cement clinker properties. Moreover, the formation of the major components (C3S, C2S, C3A and C4AF) of the produced clinkers(sintered at 1450℃) was corroborated by X-Ray Diffraction (XRD).

  10. Recycling the product of thermal transformation of cement-asbestos for the preparation of calcium sulfoaluminate clinker.

    Science.gov (United States)

    Viani, Alberto; Gualtieri, Alessandro F

    2013-09-15

    According to recent resolutions of the European Parliament (2012/2065(INI)), the need for environmentally friendly alternative solutions to landfill disposal of hazardous wastes, such as asbestos-containing materials, prompts their recycling as secondary raw materials (end of waste concept). In this respect, for the first time, we report the recycling of the high temperature product of cement-asbestos, in the formulation of calcium sulfoaluminate cement clinkers (novel cementitious binders designed to reduce CO₂ emissions), as a continuation of a previous work on their systematic characterization. Up to 29 wt% of the secondary raw material was successfully introduced into the raw mix. Different clinker samples were obtained at 1250 °C and 1300 °C, reproducing the phase composition of industrial analogues. As an alternative source of Ca and Si, this secondary raw material allows for a reduction of the CO₂ emissions in cement production, mitigating the ecological impact of cement manufacturing, and reducing the need for natural resources.

  11. Integrated Utilization of Sewage Sludge and Coal Gangue for Cement Clinker Products: Promoting Tricalcium Silicate Formation and Trace Elements Immobilization

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    Zhenzhou Yang

    2016-04-01

    Full Text Available The present study firstly proposed a method of integrated utilization of sewage sludge (SS and coal gangue (CG, two waste products, for cement clinker products with the aim of heat recovery and environment protection. The results demonstrated that the incremental amounts of SS and CG addition was favorable for the formation of tricalcium silicate (C3S during the calcinations, but excess amount of SS addition could cause the impediment effect on C3S formation. Furthermore, it was also observed that the C3S polymorphs showed the transition from rhombohedral to monoclinic structure as SS addition was increased to 15 wt %. During the calcinations, most of trace elements could be immobilized especially Zn and cannot be easily leached out. Given the encouraging results in the present study, the co-process of sewage sludge and coal gangue in the cement kiln can be expected with a higher quality of cement products and minimum pollution to the environment.

  12. Utilization of Palm Oil Clinker as Cement Replacement Material

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    Jegathish Kanadasan

    2015-12-01

    Full Text Available The utilization of waste materials from the palm oil industry provides immense benefit to various sectors of the construction industry. Palm oil clinker is a by-product from the processing stages of palm oil goods. Channelling this waste material into the building industry helps to promote sustainability besides overcoming waste disposal problems. Environmental pollution due to inappropriate waste management system can also be drastically reduced. In this study, cement was substituted with palm oil clinker powder as a binder material in self-compacting mortar. The fresh, hardened and microstructure properties were evaluated throughout this study. In addition, sustainability component analysis was also carried out to assess the environmental impact of introducing palm oil clinker powder as a replacement material for cement. It can be inferred that approximately 3.3% of cement production can be saved by substituting palm oil clinker powder with cement. Reducing the utilization of cement through a high substitution level of this waste material will also help to reduce carbon emissions by 52%. A cleaner environment free from pollutants can be created to ensure healthier living. Certain industries may benefit through the inclusion of this waste material as the cost and energy consumption of the product can be minimized.

  13. Cement Formation:A Success Story in a Black Box: High Temperature Phase Formation of Portland Cement Clinker

    OpenAIRE

    2012-01-01

    Cement production has been subject to several technological changes, each of which requires detailed knowledgeabout the high multiplicity of processes, especially the high temperature process involved in the rotary kiln. This article gives an introduction to the topic of cement, including an overview of cement production, selected cement properties, and clinker phase relations. An extended summary of laboratory-scale investigations on clinkerization reactions, the most important reactions in ...

  14. Coatability of cement clinker on basic refractories

    Science.gov (United States)

    Guo, Zongqi

    The aim of this work is to develop an effective and practicable method to evaluate the coatability of cement clinker on basic refractory bricks, susceptible to be translated in numbers. Determinations of the dominant influential factors, and assessment of reliability, as well as of coating mechanisms on different basic bricks, are to be tackled. Raw meal has been investigated in terms of chemical and phase compositions, particle size distribution, using DTA and TGA, as well as x-ray diffraction and microstructural analysis after heating at different temperatures. Raw meal calcinated at 1000°C for 4 hours contains plenty of free lime. Over 1350°C, most of liquid phases and belite C2S have formed. At 1450°C, there are still some clusters of free lime in clinker. Alite C 3S becomes dominant phase in clinker fired at temperature of 1550°C, with reduction of belite C2S and depletion of free lime. Samples of 50 x 50 x 60 mm are directly cut dry from available bricks (without water-cooling) and the sandwich is prepared using the cut surfaces. At least six pieces are needed to have three sandwiches for all tested brands of basic refractories. Mean value of the modulus of rupture obtained from three replicates is considered as representative of the adherence strength of the coating. Statistical process analysis was also used to plan and carry out experiments carefully so as to confirm repeatability and reproducibility of the sandwich protocol. Variability of +/-0.5 MPa is considered to be acceptable on a 5 MPa measured value. The following conclusions can be derived from the results: (1) The most significant effects on adherence strength are the compressive loads, the nature of the raw meal, the heating temperature and the holding time, ranked in the order of importance. (2) A ruggedness test indicates that the sandwich test is insensitive to minor changes, in holding time, paste thickness and mixing mode of the paste. (3) Adherence mechanism of cement clinker on doloma

  15. Effect of Microwave Processing on Aluminate Cement Clinkering

    Institute of Scientific and Technical Information of China (English)

    DONG Jianmiao; LONG Shizong

    2005-01-01

    When raw materials were preheated to 1000-1300 ℃ by electricity and microwave was inputted for 1 min 5 s-4 mins, then alunminate clinkers were obtained. The f-CaO contents,XRD patterns and lithofacies analysis show that the microwave processing accelerates the clinkering reaction,and Fe2O3 is contributed to the aluminate cement clinkering. The appearance of liquid phase in process of microwave heating increases the microwave absorbability of materials greatly.

  16. 76 FR 76760 - Gray Portland Cement and Cement Clinker From Japan

    Science.gov (United States)

    2011-12-08

    ... Portland Cement and Cement Clinker From Japan Determination On the basis of the record \\1\\ developed in the... antidumping duty order on gray Portland cement and cement clinker from Japan would be likely to lead to... the Commission are contained in USITC Publication 4281 (December 2011), entitled Gray Portland...

  17. 76 FR 24519 - Gray Portland Cement and Cement Clinker From Japan; Institution of a Five-Year Review Concerning...

    Science.gov (United States)

    2011-05-02

    ... COMMISSION Gray Portland Cement and Cement Clinker From Japan; Institution of a Five-Year Review Concerning the Antidumping Duty Order on Gray Portland Cement and Cement Clinker From Japan AGENCY: United States... determine whether revocation of the antidumping duty order on gray portland cement and cement clinker...

  18. 76 FR 50252 - Gray Portland Cement and Cement Clinker From Japan; Scheduling of an Expedited Five-Year Review...

    Science.gov (United States)

    2011-08-12

    ... COMMISSION Gray Portland Cement and Cement Clinker From Japan; Scheduling of an Expedited Five-Year Review Concerning the Antidumping Duty Order on Gray Portland Cement and Cement Clinker From Japan AGENCY: United... cement and cement clinker from Japan would be likely to lead to continuation or recurrence of...

  19. Utilization of municipal solid waste incineration ash in Portland cement clinker

    Energy Technology Data Exchange (ETDEWEB)

    Lam, Charles Hoi King; Barford, John Patrick; McKay, Gordon [Hong Kong University of Science and Technology, Department of Chemical and Biomolecular Engineering, Hong Kong (China)

    2011-08-15

    Municipal solid waste incineration (MSWI) ash is used in part as raw materials for cement clinker production by taking advantage of the high contents of SiO{sub 2}, Al{sub 2}O{sub 3}, and CaO. It is necessary for environmental reasons to establish a material utilization system for the incineration waste ash residue instead of disposing these ashes into landfill. The aim of this paper is to study the feasibility of replacing clinker raw materials by waste ash residue for cement clinker production. MSWI bottom ash and MSWI fly ash are the main types of ashes being evaluated. The ashes were mixed into raw mixture with different portions of ash residue to produce cement clinker in a laboratory furnace at approximately 1400 C. X-ray diffraction and X-ray fluorescence techniques were used to analyze the phase chemistry and chemical composition of clinkers in order to compare these ash-based clinkers with commercial Portland cement clinker. (orig.)

  20. Adherence Characteristics of Cement Clinker on Basic Bricks

    Institute of Scientific and Technical Information of China (English)

    GUO Zongqi; Michel Rigaud

    2002-01-01

    Based on the sandwich test, adherence mechanisms of cement clinker on various basic bricks were tackled by microstructural observations with help of cathodoluminescence technique. Doloma based bricks offer sufficient lime to react with clinker, forming C3 S rich layer and initializing superior adherence. However, clinker with low silica ratio leads to MgO agglomeration at the interface of doloma bricks, which reduces adherence strength. On magnesia spinel bricks, fine, crystalline spinel easily reacts with lime containing phases from clinker to form lowmelting phases and belite zone, which shows high adherence performance. Lack of fine spinel in magnesia spinel bricks results in poor adherence.

  1. Substitution of the clayey mineral component by lignite fly ash in portland cement clinker synthesis

    Directory of Open Access Journals (Sweden)

    Jovanović Nataša

    2006-01-01

    Full Text Available Fly ash from four power plants in Serbia (PP "Morava" - Svilajnac, PP "Kolubara" - Veliki Grijani, PP "Kostolac" - units B1 and B2 - Kostolac and PP "Nikola Tesla" - units A and B - Obrenovac was utilized as the starting raw component for Portland cement clinker synthesis. Limestone and quartz sand from the "Holcim - Serbia, a.d." cement factory were the other two starting raw components. Based on the chemical composition of the raw components and from the projected cement moduli, the amounts of raw components in the raw mixtures were calculated. Six different raw mixtures were prepared - each one consisted of limestone, sand and different fly ash. A raw mixture from the industrial production of the "Holcim - Serbia, a.d." cement factory was used as the reference material. The prepared raw mixtures were sintered in a laboratory furnace at 1400°C. The chemical and mineralogical compositions of the synthesized clinkers were determined. The characteristics of clinkers, based on fly ash, were compared to the characteristics of the industrial Portland cement clinker from the "Holcim - Serbia, a.d." cement factory. The results of the investigation showed that fly ash from power plants in Serbia can be suitable for Portland cement clinker synthesis.

  2. Optimization of the Content of Tricalcium Silicate of High Cementing Clinker

    Institute of Scientific and Technical Information of China (English)

    CHEN Lin; SHEN Xiaodong; MA Suhua; HUANG Yeping; ZHONG Baiqian

    2011-01-01

    Optimization of the content of tricalcium silicate (C3S) of high cementing clinker was investigated. The content of free-CaO(f-CaO), mineral composite, the content of C3S in the clinker and the hydration product were analyzed by chemical analysis and X-ray diffraction (XRD). "K Value" method of QXRD was selected as a quantitative analysis way to measure the content of C3S, and the strength of cement paste was determined. The results show that at a water cement ratio of 0.29, the strength of cement paste with 73% C3S can be up to 97.5 MPa at 28 days age. The strength at 28 d of cement with 73% C3S is 16% higher than that with 78% C3S at water requirement for normal consistency. The relationship between the strength of high cementing Portland cement and the content of C3S in the clinker is nonlinear. According to the strength of cement paste, the optimal content of C3S in cement clinker is around 73% in this paper.

  3. Clinkering and hydration of belite-ye'elimite-alite cement

    OpenAIRE

    Londono-Zuluaga, Diana; Tobón, Jorge Iván; Aranda, Miguel A. G.; SANTACRUZ, ISABEL; De la Torre, Angeles G.

    2017-01-01

    Some belite-ye´elimite-ferrite (BYF) cements present low mechanical strengths mainly due to the slow reactivity of belite. A solution to this problem may be the activation of BYF clinkers by preparing them with a coexistence of alite and ye´elimite, which are known as belite-alite-ye´elimite (BAY) cements. The objective of this work was the preparation of BAY mortars that show higher mechanical strengths than BYF mortars. In order to attain this, the clinkering conditions to prepare BAY-c...

  4. Distribution of sulfate between phases in Portland cement clinkers

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, H.F.W.

    1999-08-01

    Sulfate can occur in Portland cement clinkers as alkali sulfates, potassium calcium sulfate (calcium langbeinite), anhydrite, and as a substituent in the major phases, especially alite and belite. Data for the contents in alit and belite are reviewed and relations to bulk clinker composition are discussed. Evidence on sulfate distribution from extraction procedures is similarly considered. A procedure for predicting sulfate distribution from bulk composition is described and tested and potential sources of error in such calculations are discussed. The evidence does not support suggests that, in concrete made with present-day cements and not subjected to an elevated temperature, damage through delayed ettringite formation can occur for reasons connected with the SO{sub 3} present in the clinker.

  5. The assessment of clinker and cement regenerated from completely recyclable concrete

    OpenAIRE

    De Schepper, Mieke; Vernimmen, Lies; De Belie, Nele; De Buysser, Klaartje; Van Driessche, Isabel

    2011-01-01

    As the construction sector uses 50% of the earth’s raw material and produces 50% of its waste, the development of more durable and sustainable building products is crucial. Nowadays, Construction and Demolition Waste (CDW) is already used as recycled aggregates in low-value concrete applications, since it is mostly inert material. On the other hand, the general trend today for the cement industries is the use of alternative raw materials for the production of cement clinker. From this and the...

  6. Effect of Selected Alternative Fuels and Raw Materials on the Cement Clinker Quality

    Science.gov (United States)

    Strigáč, Július

    2015-11-01

    The article deals with the study of the effects of alternative fuels and raw materials on the cement clinker quality. The clinker quality was expressed by the content of two principal minerals alite C3S and belite C2S. The additions of alternative fuels ashes and raw materials, in principle, always increased the belite content and conversely reduced the amount of alite. The alternative fuels with high ash content were used such as the meat-bone meal, sewage sludge from sewage treatment plants and paper sludge and the used alternative raw materials were metallurgical slags - granulated blastfurnace slag, air cooled blastfurnace slag and demetallized steel slag, fluidized bed combustion fly ash and waste glass. Meat-bone meal, sewage sludge from sewage treatment plants and paper sludge were evaluated as moderately suitable alternative fuels which can be added in the amounts of 2.8 wt. % addition of meat-bone meals ash, 3.64 wt. % addition of sewage sludge ash and 3.8 wt. % addition of paper sludge ash to the cement raw mixture. Demetallised steel slag is suitable for production of special sulphate resistant cement clinker for CEM I -SR cement with addition up to 5 wt. %. Granulated blastfurnace slag is a suitable alternative raw material with addition 4 wt. %. Air cooled blastfurnace slag is a suitable alternative raw material with addition 4.2 wt. %. Waste glass is not very appropriate alternative raw material with addition only 1.16 wt. %. Fluidized bed combustion fly ash appears not to be equally appropriate alternative raw material for cement clinker burning with less potential utilization in the cement industry and with addition 3.41 wt. %, which forms undesired anhydrite CaSO4 in the cement clinker.

  7. Effect of Selected Alternative Fuels and Raw Materials on the Cement Clinker Quality

    Directory of Open Access Journals (Sweden)

    Strigáč Július

    2015-11-01

    Full Text Available The article deals with the study of the effects of alternative fuels and raw materials on the cement clinker quality. The clinker quality was expressed by the content of two principal minerals alite C3S and belite C2S. The additions of alternative fuels ashes and raw materials, in principle, always increased the belite content and conversely reduced the amount of alite. The alternative fuels with high ash content were used such as the meat-bone meal, sewage sludge from sewage treatment plants and paper sludge and the used alternative raw materials were metallurgical slags - granulated blastfurnace slag, air cooled blastfurnace slag and demetallized steel slag, fluidized bed combustion fly ash and waste glass. Meat-bone meal, sewage sludge from sewage treatment plants and paper sludge were evaluated as moderately suitable alternative fuels which can be added in the amounts of 2.8 wt. % addition of meat-bone meals ash, 3.64 wt. % addition of sewage sludge ash and 3.8 wt. % addition of paper sludge ash to the cement raw mixture. Demetallised steel slag is suitable for production of special sulphate resistant cement clinker for CEM I –SR cement with addition up to 5 wt. %. Granulated blastfurnace slag is a suitable alternative raw material with addition 4 wt. %. Air cooled blastfurnace slag is a suitable alternative raw material with addition 4.2 wt. %. Waste glass is not very appropriate alternative raw material with addition only 1.16 wt. %. Fluidized bed combustion fly ash appears not to be equally appropriate alternative raw material for cement clinker burning with less potential utilization in the cement industry and with addition 3.41 wt. %, which forms undesired anhydrite CaSO4 in the cement clinker.

  8. Microscopic Understanding of Reactivity of Clinkers for Green Cement

    Science.gov (United States)

    Durgun, Engin; Manzano, Hegoi; Pellenq, Roland J. M.; Grossman, Jeffrey C.

    2011-03-01

    Cement is the cause of up to 10 percent of global CO2 emissions, and yet, while it is one of the most common materials in use, we have remarkably little understanding of its microscopic properties. Toward this end, we use quantum mechanical simulations to examine the electronic properties and structure of cement crystals and to understand the surface reactivity of various clinker phases. Using these results, our aim is to clarify the mechanisms of cement dissolution, which is the initial stage of hydration and also one of the key processes that leads to the need for high temperature/energy manufacturing. As a first step we modeled the crystal structure of two major clinker phases, alite and belite and analyzed both electronic and mechanical properties. Next, we cleaved the clinker crystal in the simulation along different symmetry directions in order to obtain a prediction of the most stable surfaces. Dissolution occurs at the surface so accurate determination of the surface pattern is crucial. Using the computed surface energies, we can predict the full structure of the clinker nanocluster. This allows us to examine the interaction of water molecules with different nanocluster phases, in order to shed light on the dissolution mechanism and use this new understanding to predict possible novel routes for modifying and controlling the dissolution reactions.

  9. IR spectroscopy of sulphates in clinkers and cements

    Directory of Open Access Journals (Sweden)

    Vázquez, T.

    1986-03-01

    Full Text Available Infrared spectroscopy is a very useful technique in Cement Chemistry. This work is devoted to the study of a large number of sulphates that should have an incidence in false set phenomena, and they are qualitative and semi-quantitatlvely studied when they are in some degree in the clinker or in the portland cement.

    La espectroscopía infrarroja es una técnica de gran utilidad en la Química del Cemento. En el presente trabajo se aplica al estudio de numerosos sulfatos que pueden tener incidencia en el fenómeno de falso fraguado, y se estudian cualitativa y semicuantitativamente cuando forman parte del clinker o cemento portland.

  10. 76 FR 78240 - Gray Portland Cement and Clinker From Japan: Continuation of Antidumping Duty Order

    Science.gov (United States)

    2011-12-16

    ... International Trade Administration Gray Portland Cement and Clinker From Japan: Continuation of Antidumping Duty... antidumping duty order on gray portland cement and clinker from Japan, pursuant to section 751(c) of the... International Trade Commission (ITC) that revocation of the antidumping duty order on gray portland cement...

  11. Calculation of mineralogical composition of cement clinker. Cement clinker no kobutsu sosei no keisan

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, S. (The Cement Association of Japan, Tokyo (Japan))

    1991-10-01

    Based on compositional analyses of clinker minerals which have been performed using advanced performance of recent electron probe micro analyzer (EPMA), the relationship between the chemical composition of bulk clinker and chemical composition of clinker mineral is studied again with the purpose of utilizing the correlation for coefficient determination. The basic oxide content and SiO{sub 2} content are established as eigen values. Al{sub 2}O{sub 3} content and Fe{sub 2}O{sub 3} content are determined taking advantage of the correlation of bulk clinker with alite, belite and ferrite concerning Fe{sub 2}O{sub 3} content and Al{sub 2}O{sub 3}/Fe{sub 2}O{sub 3} ratio, and the relationship of constant Al{sub 2}O{sub 3} (aluminate)/Al{sub 2}O{sub 3} (ferrite) ratio (1.31 weight percent) between aluminate with ferrite. The chemical composition of bulk clinker is converted into mineral composition using the obtained 4 content data. 6 refs., 6 figs., 4 tabs.

  12. Effect of Minor Elements on Silicate Cement Clinker

    Institute of Scientific and Technical Information of China (English)

    HUANG Congyun; ZHANG Mingfei; ZHANG Meixiang; LONG Shizong; CHEN Yuankui; MA Baoguo

    2005-01-01

    The effect of rare-earth and HX addition agent on the burn-ability of silicate cement clinker was investigated by orthogonal experiment. The result shows, compared with blank sample, f- CaO of the samples added with rare-earth and HX agent drops by 84.95% , its 3d and 28d compressive strength enhances by 24.40%and 16.90%, respectively. It was discovered by means of X-ray diffraction and high temperature microscope analysis that sintering temperature of the sample added with rare-earth and HX addition agent is about 1320℃. At the same time, the burning temperature of tricalcium silicate desends and its crystal growth forming-rate increases.Tricalcium silicate content in burning clinker is higher and its crystal is larger.

  13. Use of alternative fuels in cement manufacture. Effect on clinker and cement characteristics and properties

    Directory of Open Access Journals (Sweden)

    Puertas, F.

    2004-06-01

    Full Text Available This paper compares industrial clinker and cement produced using conventional and alternative fuels (animal meal, tyres or a mixture of the two. The results show no relevant differences in terms of mineralogical composition between the clinker manufactured with alternative fuels and the product obtained using conventional fuel. Clinker produced with alternative fuels at any one factory have a very similar or even lower content in heavy metals than the product manufactured with conventional fuel in the same plant (with the sole exception of Zn when the alternative fuel used is shredded tyres. Mineralogical and morphological analyses reveal no significant differences between the two types of products that can be attributed to the type of fuel used in their manufacture. All six types of cement studied are compliant with the existing legislation as regards both physical and chemical properties. Cement compressive strength is found to be to legal standards regardless of the type of fuel used. Finally, the rheological properties of the cement paste are observed to be unaffected by the type of fuel.

    Se han estudiado clínkeres y cementos obtenidos en procesos industriales que han utilizado combustibles convencionales y combustibles alternativos (harinas cárnicas, neumáticos usados y mezclas de ambos. Los resultados obtenidos han demostrado que los clínkeres fabricados con los combustibles alternativos no presentan diferencias significativas en la composición mineralógica respecto a los obtenidos con combustibles convencionales. Los contenidos de metales pesados en los clínkeres procedentes de la misma fábrica (a excepción de los contenidos en Zn en aquéllos que utilizan neumáticos son muy similares o incluso inferiores a los fabricados con combustibles convencionales. Los análisis mineralógico y morfológico de los clínkeres no evidencian diferencias asignables al tipo de combustible utilizado. Todos los cementos estudiados cumplen

  14. 76 FR 54206 - Gray Portland Cement and Clinker From Japan: Final Results of the Expedited Third Sunset Review...

    Science.gov (United States)

    2011-08-31

    ... International Trade Administration Gray Portland Cement and Clinker From Japan: Final Results of the Expedited... review of the antidumping duty order on gray portland cement and clinker from Japan. As a result of this... duty order on gray portland cement and clinker from Japan \\1\\ pursuant to section 751(c) of the...

  15. Industrial trial to produce a low clinker, low carbon cement

    Directory of Open Access Journals (Sweden)

    Vizcaíno-Andrés, L. M.

    2015-03-01

    Full Text Available A preliminary assessment of conditions for the industrial manufacture of a new cementitious system based on clinker-calcined clay and limestone, developed by the authors, referred as “low carbon cement” is presented. The new cement enables the substitution of more than 50% of the mass of clinker without compromising performance. The paper presents the follow-up of an industrial trial carried out in Cuba to produce 130 tonnes of the new cement at a cement plant. The new material proved to fulfill national standards in applications such as the manufacture of hollow concrete blocks and precast concrete. No major differences either in the rheological or mechanical properties were found when compared with Portland cement. Environmental assessment of the ternary cement was made, which included comparison with other blended cements produced industrially in Cuba. The new cement has proven to contribute to the reduction of above 30% of carbon emissions on cement manufacture.Se presenta la evaluación preliminar de las condiciones de fabricación industrial de un nuevo sistema cementicio a partir del empleo de clínquer; arcillas calcinadas y piedra caliza; desarrollado por los autores; denominado “cemento de bajo carbono”. El nuevo cemento posibilita la reducción de más de un 50% de la masa de clínquer; sin comprometer el comportamiento del material. El presente trabajo presenta el monitoreo de la producción industrial en una planta en Cuba; de 130 t del nuevo cemento. El cemento obtenido cumple con las regulaciones nacionales de calidad y su empleo tiene similar rendimiento que el cemento Pórtland para la producción de bloques y hormigón de 25 MPa. Se realiza el análisis de impacto ambiental del cemento ternario mediante la comparación con otros cementos producidos industrialmente. El nuevo cemento puede contribuir a la reducción de más del 30% de las emisiones de CO2 asociadas a la manufactura de cemento.

  16. Morphological Analysis of White Cement Clinker Minerals: Discussion on the Crystallization-Related Defects.

    Science.gov (United States)

    Benmohamed, Mohamed; Alouani, Rabah; Jmayai, Amel; Ben Haj Amara, Abdesslem; Ben Rhaiem, Hafsia

    2016-01-01

    The paper deals with a formation of artificial rock (clinker). Temperature plays the capital role in the manufacturing process. So, it is useful to analyze a poor clinker to identify the different phases and defects associated with their crystallization. X-ray fluorescence spectroscopy was used to determine the clinker's chemical composition. The amounts of the mineralogical phases are measured by quantitative XRD analysis (Rietveld). Scanning electron microscopy (SEM) was used to characterize the main phases of white Portland cement clinker and the defects associated with the formation of clinker mineral elements. The results of a study which focused on the identification of white clinker minerals and defects detected in these noncomplying clinkers such as fluctuation of the amount of the main phases (alite (C3S) and belite (C2S)), excess of the free lime, occurrence of C3S polymorphs, and occurrence of moderately-crystallized structures are presented in this paper.

  17. RAW MEALS CONTAINING TRACE RE OXIDES TO IMPROVE QUALITY OF CEMENT CLINKER

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Clay or industrial wastes containing trace rare earth(RE) oxides as one of the components are used to burn cement clinker. When the total amount of RE orides reaches 0. 2 × 10-4 2.0 × 10-4 (wt ) , it has positive effect on the burnability of raw meals, and the Alite content in clinker increases, However, with the addition of lanthanide, the formation process of clinker and the distribution of lanthanide in clinker are different from those of yttrium. If the burning temperature is 1 450 C, yttrium shows negative effect on the formation of clinker. Therefore, to improve the quality of cement clinker, the raw meals in which yttrium content is lower and lanthanide content is higher is preferable; to reduce the consumption of coal, the raw meals that yttrium content is higher is suitable. Using raw meals containing trace RE oxides can reduce the cost of fluorite and protect enviromnent.

  18. Measurement of Monochromatic Emissivity of Cement Clinker with Various Fe2O3 Content at High Temperature

    Institute of Scientific and Technical Information of China (English)

    Z.J.Ye; C.F.Ma; 等

    1996-01-01

    An applicatiopn of the optical pyrometer is studied for measuring monochromatic emissivities of cement clinker with various Fe2O3 contnet.The idsa of using “brightness temperature” is introduced into the eimssivity measurement.In this method,there is no need for measuring an actual temperature of sample surfaces,only with determining both brightness temperatures of a sample and a blackbody can the required emissivity be evaluated according to Wien's radiation law.In practice,the cement clinker is regarded as a greybody,the monochromatic emissivity is approximately equal to the total emissivity,so a single-colour optical pyrometer is applied for this purpose,Test measurements are carried out on 10 kinds of cement clinkers,Experimental data are treated by the least square method.As a result ,the emissivity variation with temperature at a certain Fe2O3 content is quite well represented by εn=a+bT.Furthermore,this work first reported that the eimissivities of cement clinker change consierably with Fe2O3 contents.In multiple cement production this conclusion is very important.

  19. Morphological Analysis of White Cement Clinker Minerals: Discussion on the Crystallization-Related Defects

    Directory of Open Access Journals (Sweden)

    Mohamed Benmohamed

    2016-01-01

    Full Text Available The paper deals with a formation of artificial rock (clinker. Temperature plays the capital role in the manufacturing process. So, it is useful to analyze a poor clinker to identify the different phases and defects associated with their crystallization. X-ray fluorescence spectroscopy was used to determine the clinker’s chemical composition. The amounts of the mineralogical phases are measured by quantitative XRD analysis (Rietveld. Scanning electron microscopy (SEM was used to characterize the main phases of white Portland cement clinker and the defects associated with the formation of clinker mineral elements. The results of a study which focused on the identification of white clinker minerals and defects detected in these noncomplying clinkers such as fluctuation of the amount of the main phases (alite (C3S and belite (C2S, excess of the free lime, occurrence of C3S polymorphs, and occurrence of moderately-crystallized structures are presented in this paper.

  20. Experimental study on cement clinker co-generation in pulverized coal combustion boilers of power plants.

    Science.gov (United States)

    Wang, Wenlong; Luo, Zhongyang; Shi, Zhenglun; Cen, Kefa

    2006-06-01

    The idea to co-generate cement clinker in pulverized coal combustion (PCC) boilers of power plants is introduced and discussed. An experimental study and theoretical analysis showed this idea to be feasible and promising. By adding quick lime as well as other mineralizers to the coal and grinding the mixture before combustion, sulfoaluminate cement clinker with a high content of silicate (SCCHS) could be generated. The main mineral phases in SCCHS are 2CaO x SiO2 (dicalcium-silicate), 3CaO x 3Al2O3 x CaSO4 (calcium-sulfoaluminate) and 2CaO x A12O3 SiO2 (gehlenite). Performance tests showed that the SCCHS met the requirements for utilization in common construction. Based on this idea, zero solid waste generation from PCC would be realized. Furthermore, thermal power production and cement production could be combined, and this would have a significant effect on both environmental protection and natural resource saving.

  1. Evaluation of the incorporation ratio of ZnO, PbO and CdO into cement clinker.

    Science.gov (United States)

    Barros, A M; Tenório, J A S; Espinosa, D C R

    2004-08-09

    Zinc, lead, and cadmium are minor elements that might be brought by wastes to the cement kilns. This work studies the incorporation ratio of ZnO, PbO, and CdO when they are added to the clinker raw material. The cement raw material used in this work was prepared by mixing pure compounds, this choice was made to avoid the effect of other elements and provide a better understanding of the behavior of these metals during the clinkering process. The samples contained additions of 0.05, 0.10, 0.30, 0.50, 0.80 and 1.00 wt.% of a specific oxide (ZnO, PbO, or CdO) to the clinker raw-meal. The chlorine influence in the ZnO incorporation ratio was also evaluated. A device to simulate the thermal cycle imposed on the charge during the clinker production was used to evaluate the incorporation ratio of these oxides as well as thermogravimetric tests. The products of the tests in the simulator device were submitted to X-ray fluorescence chemical analysis or energy disperse scanning (EDS) microprobe analysis. The results led to the conclusions that the evaporation of Zn in cements kilns is due to the chlorine content and the Pb and Cd incorporation ratio stands around 50 wt.%.

  2. Cement clinker structure during plasma-chemical synthesis and its influence on cement properties

    Science.gov (United States)

    Sazonova, N.; Skripnikova, N.; Lucenko, A.; Novikova, L.

    2015-01-01

    The aim of this study was to determine the degree of influence of cement clinker cooling modes, synthesized in a low-temperature plasma, its structure and physico-mechanical properties. The raw mixture consisting of marble, sand, ash from thermal power plants and py- rite cinders were used, which are characterized by saturation factor (1,045); silicate (2,35) and alumina (1,22) modules. It was found that the use of different cooling rates of fused cement clinker entails changes associated with the mineralogical composition (increase of alite of 8.719,2 %), morphology (variation of the mineral alite aspect ratio of 6,7-17,5), density of the structure (change in distance between the minerals from 1 to 7,5 microns), grindability, specific surface area (2600-3650 cm2/g) and, in consequence, the activity of cement (56,973,2 MPa). Disorientation of alite mineral blocks against each other, a significant amount of microcracks, affect the increase in cement specific surface area of 14,3-21,6 %, which leads to activity growth of the system. Along with this, with the rapid cooling of the samples, alite 54CaO- 16SiO2-Al2O3 MgO is formed, with single units of the structure, more deformed relatively to C3S, which has a positive effect on the hydraulic cement activity.

  3. Manganese substitutions into the portland cement clinker phases

    Directory of Open Access Journals (Sweden)

    Puertas, F.

    1989-06-01

    Full Text Available The effect of manganese substitution into the crystal structures of the main Portland cement clinker phases (3CaO.SiO2, 2CaO.SiO2, 3CaO.Al2O3, 2CaO.Fe2O3 y 4CaO.Al2O3.Fe2O3 has been studied by X-ray and analytical electron microscopy. In oxidizing conditions, the limit of solid solution in 3CaO.SiO2 is about 0.72 ±0.11% (wt, while in 2CaO.SiO2 is 1.53±0,12%(wt. Mn solid solubility on 3CaO.Al2O3structure, in oxidizing conditions is close to 0.78 ± 0,12% (wt. In identical atmosphere, the proportion of Mn in the ferrite phases (2CaO.Fe2O3 and 4CaO.Al2O3.Fe2O3 is 6.80 ± 0.87% (wt and 6.7% (wt, respectively. To each mentioned clinker phases a solid solution formula has been proposed. In these formula, the manganese substitutions and also the different oxidation states which this element can be introduced in those crystalline structure are defined.

    Se ha estudiado, por difracción de rayos X y microanálisis por espectroscopia de energías dispersivas, el efecto de la sustitución del manganeso en las estructuras cristalinas de las fases más importantes del clinker del cemento portland (3CaO.SiO2, 2CaO.SiO2, 3CaO.Al2O3, 2CaO.Fe2O3 y 4CaO.Al2O3.Fe2O3. En condiciones oxidantes, el límite de solubilidad sólida en 3CaO.SiO2 es del orden de 0,72 ± 0,11% en peso; mientras que en 2CaO.SiO2 es de 1,53 ±0,12% en peso. La solución sólida del Mn en la estructura del 3CaO.Al2O3, en condiciones oxidantes, es próxima al 0,78 ±0,12% en peso. En idéntica atmósfera, la proporción del Mn en las fases terríficas (2CaO.Fe2O3 y 4CaO.Al2

  4. Composition Design for High C3S Cement Clinker and Its Mineral Formation

    Institute of Scientific and Technical Information of China (English)

    HOU Guihua; SHEN Xiaodong; XU Zhongzi

    2007-01-01

    A new composition of Portland cement clinker was studied, in which KH, SM and IM was 0.98,2.4 and 2.4 respectively as well as its meal added 1%CuO (in mass). Fired at 1 200 ℃,1 350 ℃,1 400℃ and 1 450 ℃ for 30 min, the resultant mineral phases component and mineral morphology were analyzed.The performances of the cement which was made of clinker burned at 1 450 ℃ and fly ash were determined. By means of QXRD, XRD and optical microscopy, it is shown that the clinker burnt at 1 450 ℃ has the larger size crystals and distinct crystal interface, in which the C3S content is 73.37% and the mineral phases is dominantly C3S, following by minor C2S, C3A and tetracalcium aluminoferrite. The results reveal that a new type of high C3S content clinker can completely be made by traditional temperature-time schedule. The performances of the cement produced from this clinker with addtion of 50% fly ash and 5% gupsum were in agreement with the 32.5 strength grade of Portland fly-ash cement. The results also show that the clinker has a significant effect of saving energy and utilizing waste slag.

  5. Development and comparison of neural network based soft sensors for online estimation of cement clinker quality.

    Science.gov (United States)

    Pani, Ajaya Kumar; Vadlamudi, Vamsi Krishna; Mohanta, Hare Krishna

    2013-01-01

    The online estimation of process outputs mostly related to quality, as opposed to their belated measurement by means of hardware measuring devices and laboratory analysis, represents the most valuable feature of soft sensors. As of now there have been very few attempts for soft sensing of cement clinker quality which is mostly done by offline laboratory analysis resulting at times in low quality clinker. In the present work three different neural network based soft sensors have been developed for online estimation of cement clinker properties. Different input and output data for a rotary cement kiln were collected from a cement plant producing 10,000 tons of clinker per day. The raw data were pre-processed to remove the outliers and the resulting missing data were imputed. The processed data were then used to develop a back propagation neural network model, a radial basis network model and a regression network model to estimate the clinker quality online. A comparison of the estimation capabilities of the three models has been done by simulation of the developed models. It was observed that radial basis network model produced better estimation capabilities than the back propagation and regression network models.

  6. Application of Cement Clinker as Ni-Catalyst Support for Glycerol Dry Reforming

    Directory of Open Access Journals (Sweden)

    Hua Chyn Lee

    2013-12-01

    Full Text Available The increase in biodiesel production inevitably yield plethora of glycerol. Therefore, glycerol has been touted as the most promising source for bio-syngas (mixture of H2 and CO production. Significantly, coking on nickel-based catalysts has been identified as a major deactivation factor in reforming technology. Indeed, coke-resistant catalyst development is essential to enhance syngas production. The current work develops cement clinker (comprised of 62.0% calcium oxide-supported nickel catalyst (with metal loadings of 5, 10, 15 and 20 wt% for glycerol dry reforming (CO2. Physicochemical characterization of the catalysts was performed using XRD, XRF, BET, TGA and FESEM-EDS techniques. Subsequently, reaction studies were conducted in a 7-mm ID fixed-bed stainless steel reactor at 1023 K with various CO2 partial pressures at constant weight-hourly space velocity (WHSV of 7.2×104 ml gcat-1 h-1. Gas compositions were determined using Agilent 3000 micro-gas chromatography (GC and Lancom III gas analyzer. Results obtained showed an increment of BET surface area up to 32-fold with Ni loading which was corroborated by FESEM images. Syngas (H2 and CO ratios of less than 2 were being produced at 1023 K. A closer scrutiny to the transient profile revealed that the presence of CO2 higher or lower than CGR 1:1 promotes the Boudouard reaction. © 2013 BCREC UNDIP. All rights reservedReceived: 30th May 2013; Revised: 27th August 2013; Accepted: 11st September 2013[How to Cite: Lee, H.C., Siew, W.K., Cheng, C.K. (2013. Preparation Application of Cement Clinker as Ni-Catalyst Support for Glycerol Dry Reforming. Bulletin of Chemical Reaction Engineering & Catalysis, 8 (2: 137-144. (doi:10.9767/bcrec.8.2.5023.137-144][Permalink/DOI: http://dx.doi.org/10.9767/bcrec.8.2.5023.137-144

  7. Experimental research on mathematical modelling and unconventional control of clinker kiln in cement plants

    Science.gov (United States)

    Rusu-Anghel, S.

    2017-01-01

    Analytical modeling of the flow of manufacturing process of the cement is difficult because of their complexity and has not resulted in sufficiently precise mathematical models. In this paper, based on a statistical model of the process and using the knowledge of human experts, was designed a fuzzy system for automatic control of clinkering process.

  8. Belite cement clinker from coal fly ash of high Ca content. Optimization of synthesis parameters

    Energy Technology Data Exchange (ETDEWEB)

    A. Guerrero; S. Goni; I. Campillo; A. Moragues [Instituto de Ciencias de la Construccion ' Eduardo Torroja' (CSIC), Madrid (Spain)

    2004-06-01

    The optimization of parameters of synthesis of belite cement clinker from Spanish coal fly ash of high Ca content is presented in this paper. The investigations were prompted by a need to reduce the CO{sub 2} emissions produced by the cement industry. Belite Ca{sub 2}SiO{sub 4} synthesis produces less CO{sub 2} than alite, the main component of Portland cement clinker. The synthesis process is based on the hydrothermal-calcination-route of the fly ash without extra additions. The hydrothermal treatment was carried out in demineralized water and a 1 M NaOH solution for 4 h at the temperatures of 100, 150, and 200{sup o} C. The precursors obtained during the hydrothermal treatment were heated at temperatures of 700, 800, 900, and 1000{sup o}C. The changes of fly ash composition after the different treatments were characterized by X-ray diffraction (XRD), FT infrared (FTIR) spectroscopy, surface area (BET-N{sub 2}), and thermal analyses. From the results obtained it was concluded that the optimum temperature of the hydrothermal treatment was 200{sup o}C, and the optimum temperature for obtaining the belite cement clinker was 800{sup o}C. 12 refs., 11 figs., 2 tabs.

  9. Quantitative XRD Analysis of Cement Clinker by the Multiphase Rietveld Method

    Institute of Scientific and Technical Information of China (English)

    HONG Han-lie; FU Zheng-yi; MIN Xin-min

    2003-01-01

    Quantitative phase analysis of Portland cement clinker samples was performed using an adaptation of the Rietveld method.The Rietveld quantitative analysis program,originally in Fortran 77 code,was significantly modified in visual basic code with windows 9X graph-user interface,which is free from the constraint of direct utilizable memory 640 k,and can be conveniently operated under the windows environment.The Rietveld quantitative method provides numerous advantages over conventional XRD quantitative method,especially in the intensity anomalies and superposition problems.Examples of its use are given with the results from other methods.It is concluded that,at present,the Rietveld method is the most suitable one for quantitative phase analysis of Portland cement clinker.

  10. Catalytic performance of cement clinker supported nickel catalyst in glycerol dry reforming

    Institute of Scientific and Technical Information of China (English)

    Hua Chyn Lee; Kah Weng Siew; Maksudur R. Khan; Sim Yee Chin; Jolius Gimbun; Chin Kui Cheng

    2014-01-01

    The paper reports the development of cement clinker-supported nickel (with metal loadings of 5 wt%, 10 wt%, 15 wt%and 20 wt%) catalysts for glycerol dry (CO2) reforming reaction. XRF results showed that CaO constituted 62.0%of cement clinker. The physicochemical character-ization of the catalysts revealed 32-folds increment of BET surface area (SBET) with the addition of nickel metal into the cement clinker, which was also corroborated by FESEM images. Significantly, XRD results suggested different types of Ni oxides formation with Ni loading, whilst Ca3SiO5 and Ca2Al0.67Mn0.33FeO5 were the main crystallite species for pure cement clinker. Temperature-programmed reduction analysis yielded three domains of H2 reduction peaks, viz. centered at approximately 750 K referred to as type-I peaks, another peaks at 820 K denoted as type-II peaks and the highest reduction peaks, type-III recorded at above 1000 K. 20 wt%Ni was found to be the best loading with the highest XG and H2 yield, whilst the lowest methanation activity. Syngas with lower H2/CO ratios (0.6 to 1.5) were readily produced from glycerol dry reforming at CO2-to-Glycerol feed ratio (CGR) of unity. Nonetheless, carbon deposit comprised of whisker type (Cv) and graphitic-like type (Cc) species were found to be in majority on 20 wt%Ni/CC catalysts.

  11. Preparation of Super Composite Cement with a Lower Clinker Content and a Larger Amount of Industrial Wastes

    Institute of Scientific and Technical Information of China (English)

    HE Zhen; LIANG Wen-quan; LI Bei-xing; LI Xiang-guo

    2002-01-01

    The effects of the grinding mode,fineness, gypsum kinds and dosage, mix proportions on properties of the composite cements consisting of slag,fly ash, limestone and a lower content clinker were investigated,respectively. The results show that when the proportions among slag, fly ash and limestone are appropriate, the grinding technology and system are reasonable, the optimized gypsums and additives are effective, the 52.5 R grade cement (52.5 R grade cement means a higher strength than 52.5 at early age ) can be prepared by clinker dosage of 50% in weight, the 42.5R or 42.5,32.5 grade composite cement containing 40% and 30% clinker also may be made, respectively. Moreover, the high performance concrete prepared from the above composite cements was studied experimentally.

  12. Deformation and mechanical properties of the expansive cements produced by inter-grinding cement clinker and MgOs with various reactivities

    OpenAIRE

    Mo, Liwu; Liu, Meng; Al-Tabbaa, Abir; Deng, Min

    2015-01-01

    This is the accepted manuscript. The final version is available from Elsevier at http://www.sciencedirect.com/science/article/pii/S0950061815000914#. Magnesia (MgO) either intrinsically contained in cement clinker or prepared separately as expansive additive has been used to compensate for the shrinkage of cementitious materials. In this study, for improving the homogenous distribution of MgOs, the cement clinker was inter-ground with MgO expansive additives with various reactivit...

  13. Clinker Burning Kinetics and Mechanism

    DEFF Research Database (Denmark)

    Telschow, Samira

    The industrial cement process is subject to several changes in order to reduce the high energy consumption and thereby increase the profitability of cement production. These changes also affect the core of the entire cement producing process: the clinker formation in the rotary kiln. Thus, in ord...... for the development/improvement of models for bed material process in the ICRK, and for the development steps to improve the reactor technology....... to maintain or even improve clinker quality (and output), we need a better understanding of the development of clinker properties inside the kiln to react upon the impact of process changes. Clinker formation in industrial rotary kilns is very complex due to a vast number of interacting parameters: kiln......: the higher the rotation velocity, the higher was the amount of agglomerates reactor walls increased. The establishment of the RKS setup will allow more realistic...

  14. Solidification of heavy metal and production of cement clinker by lead-zinc tailings%铅锌尾矿制备水泥熟料及重金属固化特性

    Institute of Scientific and Technical Information of China (English)

    何哲祥; 肖祈春; 周喜艳; 李翔; 肖威

    2015-01-01

    Taking Qiaokou lead-zinc tailings as a kind of main raw materials to produce cement, the burn-ability of raw meal, the heavy metal curing, leaching toxicity and the strength of clinker were studied. The mineral phases and microstructure of cement clinker were investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM), respectively, and the mass fractions of heavy metals in clinker were analyzed by the method ofICP−AES. The results show that portland cement which is in accordance with GB 175—2007 can be produced under the calcination temperature over 1 350℃ with 15%−16% mass fraction of lead-zinc tailings, the mass fraction of C3S reaches the maximum of 49.2%, and the compressive strength of cement in 28 d is 53.99 MPa. After incorporating the lead-zinc tailings, the mass fraction of f-CaO in clinker is less than 0.5%, and it improves the burn-ability of raw material. The averaged curing degrees of Zn, As, Cd and Pb are 89.76%, 83.62%, 73.20% and 15.19%,respectively. The leaching toxicities of As, Cd, Pb and Zn are far below the national standard of hazardous waste.%以桥口铅锌尾矿为原料制备水泥熟料,主要研究生料的易烧性、熟料的重金属固化、浸出毒性及水泥的强度。利用X线衍射(XRD)和扫描电镜(SEM)分析不同尾矿掺量及煅烧温度下水泥熟料的矿物相和微观结构,用电感耦合等离子体原子发射光谱法(ICP−AES法)分析熟料中重金属的质量分数。研究结果表明:当煅烧温度超过1350℃且加入铅锌尾矿质量分数为15%~16%时,可生产出符合GB 175—2007标准的硅酸盐水泥,其硅酸三钙(C3S)质量分数最高可达49.2%,28 d抗压强度为53.99 MPa;掺入铅锌尾矿,熟料中游离氧化钙(f-CaO)的质量分数低于0.5%,改善了生料的易烧性;在煅烧过程中,重金属Zn,As,Cd和Pb的平均固化率分别为89.76%,83.62%,73.20%和15.19%;熟料Zn,As,Cd和Pb的浸出毒性远低于危险废物的国家标准。

  15. Cement Formation

    DEFF Research Database (Denmark)

    Telschow, Samira; Jappe Frandsen, Flemming; Theisen, Kirsten

    2012-01-01

    Cement production has been subject to several technological changes, each of which requires detailed knowledge about the high multiplicity of processes, especially the high temperature process involved in the rotary kiln. This article gives an introduction to the topic of cement, including...... an overview of cement production, selected cement properties, and clinker phase relations. An extended summary of laboratory-scale investigations on clinkerization reactions, the most important reactions in cement production, is provided. Clinker formations by solid state reactions, solid−liquid and liquid...

  16. Production and hydration of calcium sulfoaluminate-belite cements derived from aluminium anodising sludge

    OpenAIRE

    da Costa, E.B.; Rodríguez, E.D.; Bernal, S.; Provis, J. L.; Gobbo, L.A.; Kirchheim, A.P.

    2016-01-01

    Calcium sulfoaluminate-belite cement (CSAB) offers lower CO2 emissions in its production, compared with Portland cement. However, for the production of CSAB a high amount of alumina is required, and the scarcity and high cost of high-purity bauxite make these cements costly at present. In this study, the use of uncalcined aluminium anodising sludge (AAS) as the main source of alumina to produce CSAB clinkers, replacing bauxite, was assessed. The CSAB clinkers produced were mainly composed of ...

  17. Mechanical Properties of Cement Clinker at High Temperature%水泥熟料的高温力学性能

    Institute of Scientific and Technical Information of China (English)

    高礼雄; 徐磊; 王秀芳; 包亦望; 杜雪刚; 李坤明

    2011-01-01

    为了解水泥熟料破碎阻力随温度的变化,在实验室制各熟料样品,并在熟料冷却阶段的不同温度点进行力学实验.分析了水泥熟料样品载荷-位移曲线、抗压强度、弹性模量等随温度的变化情况.结果表明:随温度的降低水泥熟料表现出明显的硬化特征,加载峰之后,水泥熟料的特性宏观上表现出塑性向脆性的渐次转变.在冷却阶段,水泥熟料的弹性模量和抗压强度均随温度的降低而增大,温度低于1000℃后弹性模量急剧增大.温度从1100℃降至800℃时熟料的抗压强度增幅达73.4%.%Cement clinker samples were prepared in the laboratory according to cement clinker burning process. To study the changes of cement clinker grinding resistance with temperature, mechanical experiments were carded out under different temperatures during the cooling process. Influences of the high temperature on load-displacement curve, compressive strength, elastic modulus of cement clinker were systematically studied. It is shown that the hardening phenomenon of the clinker becomes obvious with decrease of the temperature, and post-peak behaviors manifest characteristics of transforming from plasticity to brittleness. With the decrease of the temperature, the elastic modulus and compression strength of cement clinker increase. Elastic modulus increase greatly when the temperature is lower than 1 000 ℃. Compressive strength of clinker increases by 73.4% when the temperature dropped from 1 100 ℃ to 800 ℃. The experiment results provide a reference for the low-energy grinding of cement clinker at high temperature.

  18. THEORETICAL AND EXPERIMENTAL STUDIES OF ENERGY-EFFICIENT GRINDING PROCESS OF CEMENT CLINKER IN A BALL MILL

    Directory of Open Access Journals (Sweden)

    Kuznetsova M.M.

    2014-08-01

    Full Text Available The article presents results of theoretical and experimental research of grinding process of bulk materials in a ball mill. The new method of determination of energy efficiently mode of operation of ball mills in a process of a cement clinker grinding is proposed and experimentally tested.

  19. Application of the fluorescence light microscopy in the textural study of portland cement clinker

    Directory of Open Access Journals (Sweden)

    Montoto San Miguel, Modesto

    1987-03-01

    Full Text Available The application of fluorescence light microscopy in the textural study of Portland cement clinker, specially its porosity, is presented. Principles and types of the technique are commented and the suggested sample preparation method is described. The use of fluorescence microscopy allows an easier study of the clinker porosity, and very proper images for automated quantification can be obtained. Besides, the samples can also be observed by reflected-light polarizing microscopy.

    Se presenta la utilidad de la microscopía óptica de fluorescencia para el estudio textural del clínker de cemento Portland, especialmente su porosidad. Se comentan los fundamentos y modalidades de la técnica, y se describe el método recomendado de preparación de muestras. La utilización de la microscopía de fluorescencia permite un estudio más fácil de la porosidad, obteniéndose imágenes muy apropiadas para su cuantificación mediante técnicas automatizadas. Además, las muestras para fluorescencia pueden ser estudiadas complementariamente por microscopía óptica de polarización por luz reflejada.

  20. Reduction of clinkerization temperature by using phosphogypsum

    Energy Technology Data Exchange (ETDEWEB)

    Kacimi, L. [Laboratory of Processes Engineering, Faculty of Sciences, Department of Chemistry, University of Sciences and Technology of Oran (U.S.T.O), B.P.1505, El M' nouar, U.S.T.O, Oran (Algeria)]. E-mail: kacimi20002000@yahoo.fr; Simon-Masseron, A. [Laboratoire de Materiaux a Porosite Controlee, CNRS UMR 7016, Universite de Haute Alsace, 3 rue Alfred Werner, 68093 Mulhouse Cedex (France)]. E-mail: A.Simon@univ-mulhouse.fr; Ghomari, A. [Laboratory of Materials Engineering, Department of Chemistry, University of Mostaganem, Cite 1500 Logements, Mostaganem (Algeria)]. E-mail: belkey@hotmail.com; Derriche, Z. [Laboratory of Processes Engineering, Faculty of Sciences, Department of Chemistry, University of Sciences and Technology of Oran (U.S.T.O), B.P.1505, El M' nouar, U.S.T.O, Oran (Algeria)

    2006-09-01

    Valorization of phosphogypsum as mineralizer in the burning of Portland cement clinker was studied in our laboratory. X-ray fluorescence, optical microscope technique and powder X-ray diffraction were then used to characterize the synthesized clinker and its raw mixture in terms of chemical composition and clinker mineralogical composition. The effects of phosphogypsum on structural and morphological properties of clinker minerals and on the presence of alite were followed by scanning electron microscopy combined with microprobe analysis. The addition of phosphogypsum to the cement raw mixture shows that the burning temperature decreases and therefore improves the production process of clinker. The addition of 10% phosphogypsum permits a complete clinkerization at low burning temperature (1200 deg. C), instead of 1470 deg. C, which increases the cement factory efficiency by 25% and extends the service life of furnace fire brick. Structural and morphological analysis of clinker produced under the new conditions show that phosphogypsum preserve perfectly the crystalline structure of silicate phases, which leads to the improvement of physical and mechanical properties of cement.

  1. Reduction of clinkerization temperature by using phosphogypsum.

    Science.gov (United States)

    Kacimi, L; Simon-Masseron, A; Ghomari, A; Derriche, Z

    2006-09-01

    Valorization of phosphogypsum as mineralizer in the burning of Portland cement clinker was studied in our laboratory. X-ray fluorescence, optical microscope technique and powder X-ray diffraction were then used to characterize the synthesized clinker and its raw mixture in terms of chemical composition and clinker mineralogical composition. The effects of phosphogypsum on structural and morphological properties of clinker minerals and on the presence of alite were followed by scanning electron microscopy combined with microprobe analysis. The addition of phosphogypsum to the cement raw mixture shows that the burning temperature decreases and therefore improves the production process of clinker. The addition of 10% phosphogypsum permits a complete clinkerization at low burning temperature (1200 degrees C), instead of 1470 degrees C, which increases the cement factory efficiency by 25% and extends the service life of furnace fire brick. Structural and morphological analysis of clinker produced under the new conditions show that phosphogypsum preserve perfectly the crystalline structure of silicate phases, which leads to the improvement of physical and mechanical properties of cement.

  2. Influence of clinker grinding-aids on the intrinsic characteristics of cements and on the behaviour of mortars

    Directory of Open Access Journals (Sweden)

    Fernández Luco, L.

    2003-12-01

    Full Text Available In the production of portland cement, grinding aids are used to improve the grinding stage and reduce the energy required to achieve the required fineness. These additives remain in the final product and they might influence the characteristics and properties of the cement, and thus, mortar and concrete. This paper presents an evaluation of two grinding-aid additives used in the production of portland cement ground in a ball mill at a laboratory stage, with suitable proportions of portland cement clinker and gypsum. A control cement mix was also produced without using any admixture and the results are shown on a comparative basis. Conclusions indicate that grinding-aids additives have some influence on the characteristics of portland cement produced, increasing their specific surface and modifying microstructure and its packing ability. Mortars and concretes made with cements ground with the addition of gringing-aids exhibit higher strength at any age and a reduced water demand. Special attention should be taken to consider any interaction with water-reducing admixture in concretes and mortars.

    En la fabricación de cemento portland es una práctica creciente la utilización de aditivos para optimizar el proceso de molienda; éstos quedan incorporados en el producto final y pueden influir sobre las características y propiedades del cemento, morteros y hormigones. En este trabajo se presenta la evaluación de dos aditivos comerciales en la molienda conjunta de clínker de cemento portland y yeso comercial, tratados en un molino a bolas a escala de laboratorio, en forma comparativa con un cemento sin aditivo producido en forma equivalente. Las conclusiones indican que los aditivos de molienda tienen influencia en las características del cemento resultante, incrementando su superficie y modificando su microestructura y estado de agregación; los morteros mejoran sus prestaciones mecánicas a todas las edades y se reduce la demanda de agua

  3. Utilization of flotation wastes of copper slag as raw material in cement production.

    Science.gov (United States)

    Alp, I; Deveci, H; Süngün, H

    2008-11-30

    Copper slag wastes, even if treated via processes such as flotation for metal recovery, still contain heavy metals with hazardous properties posing environmental risks for disposal. This study reports the potential use of flotation waste of a copper slag (FWCS) as iron source in the production of Portland cement clinker. The FWCS appears a suitable raw material as iron source containing >59% Fe(2)O(3) mainly in the form of fayalite (Fe(2)SiO(4)) and magnetite (Fe(3)O(4)). The clinker products obtained using the FWCS from the industrial scale trial operations over a 4-month period were characterised for the conformity of its chemical composition and the physico-mechanical performance of the resultant cement products was evaluated. The data collected for the clinker products produced using an iron ore, which is currently used as the cement raw material were also included for comparison. The results have shown that the chemical compositions of all the clinker products including those of FWCS are typical of a Portland cement clinker. The mechanical performance of the standard mortars prepared from the FWCS clinkers were found to be similar to those from the iron ore clinkers with the desired specifications for the industrial cements e.g. CEM I type cements. Furthermore, the leachability tests (TCLP and SPLP) have revealed that the mortar samples obtained from the FWCS clinkers present no environmental problems while the FWCS could act as the potential source of heavy metal contamination. These findings suggest that flotation wastes of copper slag (FWCS) can be readily utilised as cement raw material due to its availability in large quantities at low cost with the further significant benefits for waste management/environmental practices of the FWCS and the reduced production and processing costs for cement raw materials.

  4. Numerical simulation of thermal-hydraulic processes in the riser chamber of installation for clinker production

    Directory of Open Access Journals (Sweden)

    Borsuk Grzegorz

    2016-03-01

    Full Text Available Clinker burning process has a decisive influence on energy consumption and the cost of cement production. A new problem is to use the process of decarbonization of alternative fuels from waste. These issues are particularly important in the introduction of a two-stage combustion of fuel in a rotary kiln without the typical reactor-decarbonizator. This work presents results of numerical studies on thermal-hydraulic phenomena in the riser chamber, which will be designed to burn fuel in the system where combustion air is supplied separately from the clinker cooler. The mathematical model is based on a combination of two methods of motion description: Euler description for the gas phase and Lagrange description for particles. Heat transfer between particles of raw material and gas was added to the numerical calculations. The main aim of the research was finding the correct fractional distribution of particles. For assumed particle distribution on the first stage of work, authors noted that all particles were carried away by the upper outlet to the preheater tower, what is not corresponding to the results of experimental studies. The obtained results of calculations can be the basis for further optimization of the design and operating conditions in the riser chamber with the implementation of the system.

  5. Numerical simulation of thermal-hydraulic processes in the riser chamber of installation for clinker production

    Science.gov (United States)

    Borsuk, Grzegorz; Dobrowolski, Bolesław; Nowosielski, Grzegorz; Wydrych, Jacek; Duda, Jerzy

    2016-03-01

    Clinker burning process has a decisive influence on energy consumption and the cost of cement production. A new problem is to use the process of decarbonization of alternative fuels from waste. These issues are particularly important in the introduction of a two-stage combustion of fuel in a rotary kiln without the typical reactor-decarbonizator. This work presents results of numerical studies on thermal-hydraulic phenomena in the riser chamber, which will be designed to burn fuel in the system where combustion air is supplied separately from the clinker cooler. The mathematical model is based on a combination of two methods of motion description: Euler description for the gas phase and Lagrange description for particles. Heat transfer between particles of raw material and gas was added to the numerical calculations. The main aim of the research was finding the correct fractional distribution of particles. For assumed particle distribution on the first stage of work, authors noted that all particles were carried away by the upper outlet to the preheater tower, what is not corresponding to the results of experimental studies. The obtained results of calculations can be the basis for further optimization of the design and operating conditions in the riser chamber with the implementation of the system.

  6. Calcination of kaolinite clay particles for cement production

    DEFF Research Database (Denmark)

    Gebremariam, Abraham Teklay; Yin, Chungen; Rosendahl, Lasse

    2014-01-01

    Kaolinite rich clay particles calcined under certain conditions can attain favorable pozzolanic properties and can be used to substitute part of the CO2 intensive clinker in cement production. To better guide calcination of a clay material, a transient one-dimensional single particle model...

  7. Utilization of waste heat from rotary kiln for burning clinker in the cement plant

    OpenAIRE

    2016-01-01

    Cement subsector next to the glass industry is counted among one of the most energy-intensive industries, which absorbs approx. 12-15% of the total energy consumed by the industry. In the paper various methods of energy consumption reduction of in the cement industry are discussed. Cement production carries a very large emissions of greenhouse gases, where CO2 emissions on a global scale with the industry than approx. 5%. Great opportunity in CO2 emissions reduction in addition to the recover...

  8. Clinkering and early age hydration characterization of Belite-Alite Calcium Sulfoaluminate (BACSA) cements

    OpenAIRE

    Londono-Zuluaga, Diana; Álvarez-Pinazo, Gema; Tobón, Jorge Iván; Aranda, Miguel A. G.; SANTACRUZ, ISABEL; De la Torre, Angeles G.

    2015-01-01

    In this work, four BACSA clinkers with different compositions (belite ~ 70-55 wt %, alite ~ 10-15 wt % and ye’elimite ~ 10-15 wt %) were synthesized (at laboratory scale). Lime, gypsum, kaolin and sand were used as raw materials and clinkering temperatures from 1280 to 1300 ºC were studied. Every BACSA clinker was chemically and mineralogically characterized through X-ray fluorescence and laboratory X-ray powder diffraction (LXRPD), the latter in combination with the Rietveld methodology to o...

  9. Utilization of waste heat from rotary kiln for burning clinker in the cement plant

    Directory of Open Access Journals (Sweden)

    Sztekler Karol

    2016-01-01

    Full Text Available Cement subsector next to the glass industry is counted among one of the most energy-intensive industries, which absorbs approx. 12-15% of the total energy consumed by the industry. In the paper various methods of energy consumption reduction of in the cement industry are discussed. Cement production carries a very large emissions of greenhouse gases, where CO2 emissions on a global scale with the industry than approx. 5%. Great opportunity in CO2 emissions reduction in addition to the recovery of waste heat is also alternative fuels co-firing in cement kilns [1], [2]. In the cement sector interest in fitting-usable waste energy is growing in order to achieve high rates of savings and hence the financial benefits, as well as the environment ones [3]. In the process of cement production is lost irretrievably lot of energy and reduction of these losses on a global scale gives a visible saving of consumed fuel. The aim of this study is to investigate the possibility of waste heat use in Rudniki Cement Plant near to Czestochowa. After analyzing of all waste heat sources will be analyzed the heat emitted by radiation from the surface of the rotary kiln at the relevant facility. On the basis of thermal-flow calculations the most favorable radiative heat exchanger will be designed. The calculations based on available measurements provided by the cement plant, a thermal power of the heat exchanger, the heat exchange surface, the geometry of the heat exchanger, and other important parameters will be established. In addition the preliminary calculations of hydraulic losses and set directions for further work will be carried out. Direct benefits observed with the introduction of the broader heat recovery technology, is a significant increase in energy efficiency of the industrial process, which is reflected in the reduction of energy consumption and costs. Indirectly it leads to a reduction of pollution and energy consumption.

  10. Utilization of red mud in cement production: a review.

    Science.gov (United States)

    Liu, Xiaoming; Zhang, Na

    2011-10-01

    Red mud is a solid waste residue of the digestion of bauxite ores with caustic soda for alumina production. Its disposal remains a worldwide issue in terms of environmental concerns. During the past decades, extensive work has been done by a lot of researchers to develop various economic ways for the utilization of red mud. One of the economic ways is using red mud in cement production, which is also an efficient method for large-scale recycling of red mud. This paper provides a review on the utilization of red mud in cement production, and it clearly points out three directions for the use of red mud in cement production, namely the preparation of cement clinkers, production of composite cements as well as alkali-activated cements. In the present paper, the chemical and mineralogical characteristics of red mud are summarized, and the current progresses on these three directions are reviewed in detail.

  11. Follow up of the glassy phase formation as silicon oxide was added to Brownmillerite phase of Portland cement clinker

    Energy Technology Data Exchange (ETDEWEB)

    Hassaan, M. Y., E-mail: yousry@tedata.net.eg; Salem, S. M.; Ebrahim, F. M. [Al-Azhar University, Moessbauer Lab, Physics Department, Faculty of Science (Egypt)

    2009-01-15

    Brownmillerite phase is one of the four main phases of Portland cement clinker. It was prepared as pure C{sub 4}AF{sup 1} and C{sub 4}AF with different amount of SiO{sub 2}, (5, 10, 15, 20, 25, and 40 mol%) by addition. Pure C{sub 4}AF was prepared using CaO, Al{sub 2}O{sub 3} and Fe{sub 2}O{sub 3} according to the ratios 4:1:1. Each sample mixture was fired at 1,400 deg. C for 1 h then ground and introduced again to 1,400 deg. C for 1/2 h then quenched in air. The prepared samples were ground and measured using x-ray diffraction, scanning electron microscope, A.C. conductivity and Moessbauer spectroscopy. The results were correlated and discussed. The main finding is the formation of a glassy phase besides the C{sub 4}AF structure, in addition to the formation of the C{sub 2}S phase of cement clinker as SiO{sub 2} addition was upgraded. The electrical conductivity results showed that the 20 mol% SiO{sub 2} sample has the lowest ({sigma}) value.

  12. CERAMIC WASTES AS RAW MATERIALS IN PORTLAND CEMENT CLINKER FABRICATION.· CHARACTERIZATION AND ALKALINE ACTIVATION

    OpenAIRE

    2006-01-01

    [EN] The world-wide cementindustry is seeking experimentalavenues that wi// lead to cementproduction that is less energy-intensive/ less damaging to the surrounding environment and less prolific in GHGemissions. In Spain andEurope in general, this approach is who//y consistent with the concept of sustainability and compliance with the Kyoto Protocol. The use ofdifferent kinds of industrial waste and by-products as alternative materials in cement manufacture has proved to ...

  13. Research of fluidized bed cement clinker sintering system by pilot plant; Ryudosho cement shosei gijutsu no kaihatsu. 7

    Energy Technology Data Exchange (ETDEWEB)

    Sugiyama, T. [Center for Coal Utilization, Japan, Tokyo (Japan); Sato, N.; Hashimoto, I.; Nakatsuka, M. [The Cement Association of Japan, Tokyo (Japan)

    1996-09-01

    While a cement manufacturing process generally performs sintering by using a rotary kiln, a development work has been carried out as a subsidy operation of the Agency of Natural Resources and Energy on a cement sintering technology using a fluidized bed consisted of two furnaces: a jet flow bed granulating furnace and a fluidized bed sintering furnace. This paper reports the results of tests and researches performed during fiscal 1995. A plant with a scale of 20 ton-a-day production started in 1993 after having gone through bench scale tests. The year 1995 conducted by August its performance evaluation, review of the operation method and the safety criteria, and generalization of the tests. A multi-stage cyclone system has been employed in the preheating equipment for cement material powder. A number of improvements have been realized in the aspects of construction and operation, such as stabilization of dust collecting efficiency by employing a high-efficiency type cyclone, and operation with reduced pressure variation. Based on these results, a construction had been progressed in parallel on a new plant upscaled to 200 ton-a-day production. The new plant was completed in December, 1995. 9 figs., 8 tabs.

  14. Clinker burning kinetics and mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Telschow, S.

    2012-07-01

    The industrial cement process is subject to several changes in order to reduce the high energy consumption and thereby increase the profitability of cement production. These changes also affect the core of the entire cement producing process: the clinker formation in the rotary kiln. Thus, in order to maintain or even improve clinker quality (and output), we need a better understanding of the development of clinker properties inside the kiln to react upon the impact of process changes. Clinker formation in industrial rotary kilns is very complex due to a vast number of interacting parameters: kiln dimensions, rotation velocity, temperature, gas composition, heat transfer phenomena, etc. These conditions can only be partly simulated in ordinary lab-scale experiments. Thus, the objectives of this project have been to establish test equipment to simulate the industrial clinker burning process on a laboratory scale and to conduct clinker formation experiments in order to derive knowledge on gradual clinker property development, as a function of different process parameters. A new lab-scale setup rotary kiln simulator (RKS) was designed and built for this purpose. It is assembled of two parts: an ordinary lab-scale heating furnace and a sample motion system. The motion system consists of a SiC tube, which moves the sample, placed in a Pt/Rh-crucible, at a chosen velocity through the heating furnace. Simultaneously, the sample is rotated around its horizontal axis with a chosen rotation velocity. The heating furnace consists of five individual heating zones, which are set to obtain a temperature ramp from {approx}00-1540 deg. C. Furthermore, the atmosphere in the system can be set to any mixture of N2, O2 and CO{sup 2}. Thus, the rotary kiln simulator features most important parameters of the industrial cement rotary kiln (ICRK): gradual temperature increase, rotation velocity and gas phase composition. An investigation of clinker formation vs. heating profile and

  15. 全组分废弃混凝土再生水泥熟料烧成及水化性能研究%Study of sintering process and hydration of recycled cement clinker produced from all components of waste concrete

    Institute of Scientific and Technical Information of China (English)

    艾红梅; 常钧; 卢洪正; 燕芳; 韩立东

    2013-01-01

    With regards to the existing technical problems for the cementitious reusage of waste concrete in our country which lead to the low efficiency of various component separation in waste concrete ,high production cost and large energy consumption ,a new technology roadmap is raised using all components of waste concrete as part raw materials and burning clinker for producing recycled cement . The burnability of recycled cement raw mixtures , the mineral components of recycled cement clinker and the strength and microstructure of hydrated recycled cement are all investigated .The experimental results show that the technology of recycled cement produced from all components of waste concrete is feasible and the burnability of raw mixtures is good .However ,the strength of hydrated recycled cement mortar is lower than the technical requirements of Portland cement clinker strength ,due to the difference of experimental conditions between the laboratory and plant ;sintered recycled cement clinker admixed with the seed crystals of Portland cement clinker ,its mineral compositions and hydration products are basically the same as the industrial cement clinker .In addition ,the microstructure of C-S-H gel in the hydration products is also similar .%  针对我国废弃混凝土胶凝化再生利用技术存在的组分分离导致材料利用率低、生产成本和能耗高等问题,提出利用以石灰岩为粗骨料的全组分废弃混凝土作为生料原料,煅烧熟料、制备再生水泥的新思路。研究了再生水泥的生料易烧性以及熟料的矿物组成、水化强度和水化产物的微观形貌。结果表明:全组分废弃混凝土再生水泥技术是可行的;再生水泥生料易烧性较好,熟料胶砂强度低于硅酸盐水泥熟料技术要求,试验条件是影响强度的主要因素;引入熟料晶种煅烧的再生水泥熟料,其主要矿物成分和水化产物的组成与参比工业熟料基本相同

  16. Trace elements based classification on clinkers. Application to Spanish clinkers

    OpenAIRE

    Tamás, F. D.; Abonyi, J.; Puertas, F.

    2001-01-01

    The qualitative identification to determine the origin (i.e. manufacturing factory) of Spanish clinkers is described. The classification of clinkers produced in different factories can be based on their trace element content. Approximately fifteen clinker sorts are analysed, collected from 11 Spanish cement factories to determine their Mg, Sr, Ba, Mn, Ti, Zr, Zn and V content. An expert system formulated by a binary decision tree is designed based on the collected data. The performance of the...

  17. Sustainable production of blended cement in Pakistan through addition of natural pozzolana

    Directory of Open Access Journals (Sweden)

    Ahmad Muhammad Imran

    2016-01-01

    Full Text Available In this work pozzolana deposits of district Swabi, Pakistan were investigated for partial substitution of Portland cement along with limestone filler. The cement samples were mixed in different proportions and tested for compressive strength at 7 and 28 days. The strength activity index (SAI for 10 % pozzolana, and 5% limestone blend at 7 and 28 days was 75.5% and 85.0% satisfying the minimum SAI limit of ASTM C618. Twenty two percents natural pozzolana and five percents limestone were interground with clinker and gypsum in a laboratory ball mill to compare the power consumption with ordinary Portland cement (OPC (95% clinker and 5% gypsum. The ternary blended cement took less time to reach to the same fineness level as OPC due to soft pozzolana and high grade lime stone indicating that intergrinding may reduce overall power consumption. Blended cement production using natural pozzolana and limestone may reduce the energy consumption and green house gas emissions.

  18. Petroleum sludge treatment and reuse for cement production as setting retarder

    Science.gov (United States)

    Aeslina, A. K.; Ali, B.

    2017-05-01

    Petroleum sludge is a dangerous waste that needs to be treated to avoid any contamination of soil and groundwater due to its disposal. As an attempt to treat this waste, it has been incorporated into cement production as substitution for gypsum. As results, 5% of petroleum sludge has shown effective results and could play the same role of gypsum in delaying the flash setting of cement clinker.

  19. Research on Application of Tailing with Pyrrhotite in Production of Portland Clinker%含磁黄铁矿尾矿在硅酸盐水泥中的应用

    Institute of Scientific and Technical Information of China (English)

    徐迅; 齐砚勇

    2012-01-01

    The aim of the research is that using tailing with pyrrhotite to produce Portland clinker and solidify S element in cement. It is shown that the copper tailing containing pyrrhotite in Sudbury has a wide composition scope producing Portland clinker and the minerals crystal in clinker is perfect and wellbuilt. Setting time of clinker is normal, the early strength of that is high and later strength of that increases steadily. S2- of pyrrhotitein tailing was solidified as SO42- during sintering process of clinker. At 1000 ℃ the solidification quantity reaches maximum. The best proportion of tailing in industrial production is 3%.%本实验旨在利用含磁黄铁矿尾矿生产硅酸盐水泥熟料,将有害元素硫固化在水泥中.结果表明,该尾矿可在较宽的组成范围内形成硅酸盐水泥熟料.水泥熟料凝结时间正常,早期强度较高,后期稳定增长.尾矿中所含的S2在水泥熟料煅烧过程中以SO42-形式固化在水泥熟料中,在1000℃左右固硫量最大.生产实际中以掺入3%尾矿配料为佳.

  20. NOx from cement production - reduction by primary measures

    DEFF Research Database (Denmark)

    Jensen, Lars Skaarup

    1999-01-01

    cement production processes cement is typically produced by thermally treating a mixture of limestone and clay minerals in kiln systems consisting of a rotary kiln and a calciner. Clinker burning at a temperature of about 1450 °C takes place in the internally fired rotary kiln and calcination, which...... is the most energy demanding process, takes place at lower temperature in the calciner. When dealing with NOx from solid fuel combustion it is important to consider reactions of volatile contents and char separately.Chapter 4 presents an overview of NOx from cement production. Thermal NOx dominates from......, calciner operation, fuel properties and on the NOx level from the rotary kiln. The low-NOx calciner types presently marketed are based on combinations of reburning, air staging and temperature control and seem equivalent in their ability to restrict NOx formation. If fuels with a significant volatile...

  1. DEVELOPMENT OF HYDRAULIC GYPSUM THAT CONTAINS CEMENTS THAT HAVE SULPHATED CLINKER PHASES

    Directory of Open Access Journals (Sweden)

    Mikheenkov Mikhail Arkad'evich

    2012-10-01

    Full Text Available In the article, the authors consider the feasibility of development of water-hardened gypsum that is capable of hardening in the water. The gypsum in question is made of the gypsum binding material, sulphated Portland cement, and granulated blast-furnace slag. The gypsum developed hereunder has a softening coefficient over 1 while the building gypsum content exceeds 75 %.

  2. Clinker Production from Wastes of Cellulose and Granite Industries

    Science.gov (United States)

    Fassoni, Délio Porto; de Cássia, Alvarenga Rita; Pedrotti, Leonardo; Mendes, Beatryz

    This work present a belite cement based made from two industrial waste types. Binary mixtures were prepares using waste from rock cutting and polishing industries and waste from cellulose industry (named grits), in diferente proportions. The mixed raw materials were burned at a temperature of 950 °C in an electric oven for 30 minutes and then cooled at a rate of 70 °C per minute. The mineralogical composition of the material obtained was studied by means of XRD techniques, confirming the dominance of dicalcium silicate. Mixed mortars produced with the new material, in full replacement of Portland cement, showed satisfactory performance for use in construction works. This research shows that it is possible to obtain hydraulic binders from industrial waste, at lower temperatures than the required for the consumption of non-renewable resources and energy.

  3. Utilization of Red Mud as Raw Material in the Production of Field Road Cement

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao; LUO Zhongtao; ZHANG Lei; RONG Hui; YANG Jiujun

    2016-01-01

    The total utilization amount of red mud is limited due to its high content of alkali, heavy metals and naturally occurring radioactive element. In order to rationalize the use of red mud, a typical ifeld road cement using dealkalized red mud (content of alkali lower than 1%) as raw material was ifrstly prepared in this paper. Then, a preliminary research on the radioactivity of the red mud based ifeld road cement has been carried out. For that reason, two samples of raw materials were prepared. One was with ordinary raw materials, as the control group (CG), the other was with 23w % red mud, as the experimental group (EG). The clinkers were acquired by sintering the above two raw materials at 1 400℃. Subsequently, the two types of cement prepared by the above two kinds of clinkers were tested by measuring the normal consistency, setting time, mechanical strength and drying shrinkage. Meanwhile, the hydration products of the two types of cement were examined by XRD analysis at the curing age of 6 hours, 1, 3, 7, and 28 days, respectively. The radioactivity of the two kinds of cement clinkers was then measured by gamma-ray spectrometry. The experimental results indicate that the main mineralogical phases components in the EG ifeld road cement clinkers are C3S, C2S, and C4AF, the 28 days lfexural and compressive strength of the EG ifeld road cement mortars could be up to 8.45 and 53.2 MPa, respectively. The radioactive measuring results of the EG field road cement show that the value of radium equivalent activity index (Raeq) is 254.8 Bq/Kg-1, which is lower than the upper limit.

  4. Clinker mineral hydration at reduced relative humidities

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede; Hansen, Per Freiesleben; Lachowski, Eric E.;

    1999-01-01

    Vapour phase hydration of purl cement clinker minerals at reduced relative humidities is described. This is relevant to modern high performance concrete that may self-desiccate during hydration and is also relevant to the quality of the cement during storage. Both the oretical considerations...... and experimental data are presented showing that C(3)A can hydrate at lower humidities than either C3S or C2S. It is suggested that the initiation of hydration during exposure to water vapour is nucleation controlled. When C(3)A hydrates at low humidity, the characteristic hydration product is C(3)AH(6...

  5. Scrap tire ashes in portland cement production

    Directory of Open Access Journals (Sweden)

    Mónica Adriana Trezza

    2009-01-01

    Full Text Available Scrap tires are not considered harmful waste, but their stocking and disposal are a potential health and environmental risk. Properly controlled calcinations at high temperatures make tire combustion an interesting alternative due to its high calorific power, comparable to that of fuel-oil. Consequently, using them as an alternative combustible material in cement kilns makes it possible to give it a valuable use. However, it remains to be assured whether the impurities added to the clinker through these fuels do not affect its structure or properties.This paper shows the studies carried out on different clinkers under laboratory conditions with different levels of addition of scrap tire ashes, added by partially replacing traditional fuel in cement kilns.

  6. Study on high belite cement clinker calcination with ashes from circulating fluidized bed combustion%固硫灰制备高贝利特水泥

    Institute of Scientific and Technical Information of China (English)

    吕淑珍; 陈雪梅; 卢忠远; 彭艳华

    2011-01-01

    In order to explore new utilizing approach of ashes from circulating fluidized bed combustion(CFBC ashes for short), high belite cement is prepared by using CFBC ashes to substitute partial raw materials. Calcining temperature and mineral composition of clinker are analyzed by thermogravimetric-differential thermal analysis (TG-DTA) and X-ray diffraction (XRD) respectively, and the physical mechanical properties of clinker are tested. The results show that the main minerals of high belite cement clinker are C2S,C4A3S,G2AF and CaSO4;compression strength of 3 days is more than 30 Mpa.and that of 28 days is more than 80 Mpa while incorporation of proper amount of gypsum.%为了探索固硫灰新的利用途径,利用固硫灰替代部分原料制备高贝利特水泥,采用TG-DTA综合热分析法、XRD射线衍射等方法分别确定了生料的煅烧温度和熟料的矿物组成,并对水泥的物理力学性能进行了检测.研究表明,制备的高贝利特水泥主要矿物组成是C2S、C4A3(S)、C2AF和CaSO4;掺入适量的石膏后,其3d抗压强度达到30 MPa以上,28 d抗压强度达到80 MPa以上.

  7. Simulation and Analysis of Cement Clinker Subsection Firing%水泥熟料分段烧成模拟分析

    Institute of Scientific and Technical Information of China (English)

    封培然; 邢文杰; 齐砚勇

    2011-01-01

    By establishing the calculation of the mathematical model of NSP cement rotary kiln burning zone temperature ( BZT), this paper computed two types of different cement kiln BZT, analyzed two types of different kiln temperature distribution, then put forward the idealized burn clinker piecewise model. The study shows that short kiln in transitional zone has ordinary kiln type temperature gradient approximately 8 times, but in the burning zone both almost have no temperature change and subsection firing still have 15℃ heats up. Therefore subsection firing a has good clinker reaction temperature environment, which is beneficial to improving the quality of clinker.%通过建立新型干法水泥回转窑烧成带温度计算的数学模型,计算出两种不同水泥窑型的烧成带温度,分析了两种不同窑型的温度分布,进而提出熟料分段烧成的理想化模型。研究发现:短窑在过渡带具有普通窑型约8倍的温度梯度,但是在烧成带两者几乎没有温度变化,而分段烧成依然有15℃的升温,因此分段烧成具有良好的熟料反应温度环境,有利于熟料质量的提高。

  8. Study on properties of high strength blended cements with small amount of clinker%少熟料高标号复合水泥的性能

    Institute of Scientific and Technical Information of China (English)

    程麟; 李东旭

    2001-01-01

    工业废渣用于水泥混合材的研究一直是水泥研究领域的热点问题。从实际应用看,活性高的混合材,如矿渣已得到充分的利用。而活性低的混合材,如粉煤灰,利用率较低。针对矿渣、磷渣和粉煤灰的特点,通过强度和孔结构测试,研究了少熟料高标号复合水泥。强度和孔结构研究表明,利用混合材的优势互补原理,并引入外加剂可以得到性能优异的少熟料复合水泥。%Adding industrial refuses to cement as mixing materials is a hot topic in the cememt industry. In the practice viewpoint, high active mixing materials, such as slag have been used effectively. However, the mixing materials of low activity, have not been used effectively. Blended cements of high strength with small amount of clinker and large amount of mixing materials such as blast furnace slag, phosphorous slag and fly ash were studied in this paper. By means of analysis of strength and pore structure, results showed that blended cements of small amount clinker, have good properties, it can be made by making use of some advantages of additives and adding admixtures.

  9. Glass recycling in cement production--an innovative approach.

    Science.gov (United States)

    Chen, Guohua; Lee, Harry; Young, King Lun; Yue, Po Lock; Wong, Adolf; Tao, Thomas; Choi, Ka Keung

    2002-01-01

    An innovative approach of using waste glass in cement production was proposed and tested in a laboratory and cement production plant. The laboratory characterization of 32 types of glass show that the chemical composition of glass does not vary significantly with its color or origin but depends on its application. The alkali content of glass, a major concern for cement production varies from 0 to 22%. For the glass bottles mainly found in Hong Kong waste glasses, the alkali content (Na2O) ranges from 10 to 19% with an average around 15%. There is no significant change of the SO2 content in the gas exhaust of the rotary kiln when about 1.8 t/h of glass bottles were loaded along with the 280-290 t/h raw materials. The content of NOx, mainly depends on the temperature of the kiln, does not show significant change either. The SO3 content of the clinker is comparable with that obtained without the loading of glass. The alkaline content shows a slight increase but still within three times the standard deviation obtained from the statistical data of the past year. The detailed analysis of the quality of the cement product shows that there is not any significant impact of glass for the feeding rate tested.

  10. 基于变长度单元的水泥熟料渗流换热模型研究%Seepage heat transfer model of cement clinker based on variable length unit

    Institute of Scientific and Technical Information of China (English)

    刘彬; 岳海龙; 闻岩

    2013-01-01

      堆积状态下水泥熟料的多孔质特性使得传统的气固交叉换热理论和对流换热理论难以揭示堆积体内部的换热规律。虽然渗流换热理论的引入使得堆积体换热计算结果更加接近实际,但计算过程大多忽略流体的物性变化,且计算较为复杂。本文运用拉格朗日观点和欧拉观点对高温水泥熟料堆积体的换热过程进行了分析,将真实气体状态方程引入渗流理论并结合局部热不平衡理论,建立了熟料变长度单元渗流换热数学模型,利用解析法和数值法对该模型进行求解,得到了熟料层内部流体温度和压力以及熟料温度的变化规律,研究结果为高温水泥熟料通风方案的优化提供了理论参考。%  The traditional theory of gas-solid cross heat transfer and theory of convection heat transfer are difficult to reveal the inner heat transfer law of cement clinker porous media accumulation body because of the porous characteristics of cement clinkers in stacked state. The calculation results are closer to the physical truth with the introduction of the seepage heat transfer theory, but the physical properties changes of the fluid are mostly ignored and the method is complicated. Heat transfer program of the hot ce-ment clinker accumulation body is analyzed using the Lagrangian's joint of view and the Eular's standpoint, a mathematical seepage heat transfer model of cement clinker based on variable length unit is established through the real gas state equation being introduced into seepage theory combined with the local thermal non-equilibrium theory. Variation laws of the fluid temperature and pressure and the clinker temperature in the cement clinker layer are obtained by the combination of the analytical method and the numerical method. The research results can provide a theoretical reference for optimizing the ventilation program of the high-temperature ce-ment clinker.

  11. [Release amount of heavy metals in cement product from co-processing waste in cement kiln].

    Science.gov (United States)

    Yang, Yu-Fei; Huang, Qi-Fei; Zhang, Xia; Yang, Yu; Wang, Qi

    2009-05-15

    Clinker was produced by Simulating cement calcination test, and concrete samples were also prepared according to national standard GB/T 17671-1999. Long-term cumulative release amount of heavy metals in cement product from co-processing waste in cement kiln was researched through leaching test which refers to EA NEN 7371 and EA NEN 7375, and one-dimensional diffusion model which is on the base of Fick diffusion law. The results show that availabilities of heavy metals are lower than the total amounts in concrete. The diffusion coefficients of heavy metals are different (Cr > As > Ni > Cd). During 30 years service, the cumulative release amounts of Cr, As, Ni and Cd are 4.43 mg/kg, 0.46 mg/kg, 1.50 mg/kg and 0.02 mg/kg, respectively, and the ratios of release which is the division of cumulative release amount and availability are 27.0%, 18.0%, 3.0% and 0.2%, respectively. The most important influence factor of cumulative release amount of heavy metal is the diffusion coefficient, and it is correlative to cumulative release amount. The diffusion coefficient of Cr and As should be controlled exactly in the processing of input the cement-kiln.

  12. 利用水泥窑协同处置污泥对熟料的影响%Effect of Co-disposal of Sewage Sludge in Cement Kiln on Cement Clinker

    Institute of Scientific and Technical Information of China (English)

    张智; 李舒扬; 周黔生; 梅龙云; 陆磊; 陈杰云

    2012-01-01

    Co-disposal of sewage sludge in cement kiln is an economic and feasible method of resource utilization. An appropriate ratio of sewage sludge without drying replaced cement as a raw material. The mixture was pumped into the smoke chamber at the end of the rotating kiln by the sludge pump and calcined into cement clinker using high temperature in the kiln. The physical properties and mineral composition of the cement clinkers produced with and without sludge were compared and analyzed to discuss the effect of adding sludge. The result showed that all the indexes of the cement clinker produced with sludge met the national standard. Except for consistency, there was no evident variation in particle fineness and setting time. The 28-d compressive strength and breaking strength were increased evidently, and the stability was improved. Among the main minerals of cement clinker, tricalcium silicate was increased dramatically. This was the primary cause of the increase in 28-d compressive strength and break- ing strength. Meanwhile, dicalcium silicate was decreased, and tricalcium aluminate and brownmillerite showed no evident variation. Adding an appropriate amount of sludge is beneficial to the cement clinker.%利用水泥窑协同处置污水厂污泥,是一种经济、可行的资源化利用方式.重庆富皇水泥(集团)有限公司用未经干化的污水厂污泥,以合适的比例替代部分水泥生产原材料,用污泥泵直接喷入回转窑窑尾烟室内,利用水泥窑的高温煅烧成熟料.对比分析了掺加污泥前后水泥熟料的物理性能和矿物组成,探讨掺加污泥对其影响.结果表明,掺加污泥后水泥熟料的各项指标均满足国家标准,除稠度外,细度、凝结时间均无明显变化,28 d抗压强度和抗折强度有明显增加,安定性也有所增强.水泥熟料的主要矿物中,C3S含量呈极显著增加趋势,这是28 d强度明显增加的主要原因;C2S含量明显减少,而C3A和C4AF含量没有明

  13. 预分解窑熟料煅烧%Burning Clinker in the Precalcining Kiln

    Institute of Scientific and Technical Information of China (English)

    冯晓梅

    2011-01-01

    Basic production proccss of the silicatc cement are to make raw meal;burning clinker and making into cement.The burning clinker is the core of cement preduction.The rotary kiln is main equipment of the burning clinker system,it consists of the tube-shaped object,support installation.driving installation and seal up installation etc.%硅酸盐水泥的基本生产过程是生料制备、熟料煅烧和水泥制成.熟料煅烧是水泥厂生产的核心,回转窑是熟料煅烧系统中的主要设备,回转窑主要由筒体、支承装置,传动装置、密封装置等组成.

  14. Quality design of belite–melilite clinker

    Energy Technology Data Exchange (ETDEWEB)

    Kurokawa, Daisuke, E-mail: daisuke_kurokawa@taiheiyo-cement.co.jp [R and D center, Taiheiyo Cement Corporation, Chiba 285-8655 (Japan); Department of Materials Science and Engineering, Nagoya Institute of Technology, Nagoya 466-8555 (Japan); Honma, Kenichi; Hirao, Hiroshi [R and D center, Taiheiyo Cement Corporation, Chiba 285-8655 (Japan); Fukuda, Koichiro [Department of Materials Science and Engineering, Nagoya Institute of Technology, Nagoya 466-8555 (Japan)

    2013-12-15

    We have developed a new cement clinker, consisting mainly of belite and melilite, which is capable of increasing the amount of recycled waste as a part of its raw materials. We analyzed clinkers with a wide range of compositions, and clarified the quantitative relationship between the chemical and mineral compositions. Clinkers consisting mostly of belite and melilite were successfully obtained at the CaO/SiO{sub 2} mass ratio of 1.7 to 1.9. Test cements were prepared using these clinkers and mixed with OPC for the evaluation of fluidity and strength. The belite–melilite cement was found to have good fluidity, and the belite–melilite cement mixed with OPC at up to 30% exhibited a satisfactory long term strength equivalent to the OPC, demonstrating the potential as an alternative to OPC. Electron probe microanalysis revealed the relatively high concentration of diphosphorus pentaoxide in belite, suggesting this component might contribute to the strength enhancement of the cement. -- Highlights: •A new cement clinker consisting mainly of belite and melilite was designed. •The clinker enables the use of various recycled wastes as part of its raw materials. •The relationship between the chemical and mineral compositions was clarified. •This cement mixed with OPC at up to 30% exhibited a good quality equivalent to OPC.

  15. [Utilizing the wastewater treatment plant sludge for the production of eco-cement].

    Science.gov (United States)

    Lin, Yi-Ming; Zhou, Shao-Qi; Zhou, De-Jun; Wu, Yan-Yu

    2011-02-01

    The aim of this paper was to study the effect on cement property by using of municipal sewage as additive in the process of clinker burning. Based on the standard sample P. 042. 5 from cement plant, the properties of eco-cement samples adding municipal sewage to unit raw material by 0%, 0.50%, 1.00%, 1.50%, 2.00%, 2.50% respectively and the standard sample from the cement plant were compared. According to the analysis of X-ray diffraction, microstructure, the particles size determination material change, the setting time, specific surface area, leaching toxicity and strength of cement mortar of the cement, respectively, it showed that the strength of the productions were similar to the P. 042.5 standard sample. The metal ion concentrations of Al, Fe, Ba, Mn and Ti in clinkers and raw material decreased, the initial and setting time increased, as well as the strength of the paste within the curing time of 3 days decreased with the increase of municipal sewage ratio. However, after the curing of 7 days, the strength was similar to non-sludge-mortar or even higher.

  16. Sustainable Development of the Cement Industry and Blended Cements to Meet Ecological Challenges

    OpenAIRE

    Konstantin Sobolev

    2003-01-01

    The world production of cement has greatly increased in the past 10 years. This trend is the most significant factor affecting technological development and the updating of manufacturing facilities in the cement industry. Existing technology for the production of cement clinker is ecologically damaging; it consumes much energy and natural resources and also emits pollutants. A new approach to the production of blended or high-volume mineral additive (HVMA) cement helps to improve its ecologi...

  17. Cements containing by-product gypsum

    Energy Technology Data Exchange (ETDEWEB)

    Bensted, J. [University of Greenwich, London (United Kingdom). School of Biological and Chemical Sciences

    1995-12-31

    Chemical by-product gypsum can readily replace natural gypsum in Portland cements and in blended cements like Portland pfa cement and Portland blast furnace cement without technical detriment in many instances. Indeed, sometimes the technical performance of the cement can be enhanced. The hydration chemistry is often changed, in that where there is at least some retardation of setting, more AFT phase (ettringite) is formed during early hydration at the expense of calcium silicate hydrates. By-product gypsum can also replace natural gypsum in speciality products like calcium aluminate cement-Portland cement mixes for producing quick setting cements and in calcium sulphoaluminate-type expansive cements. However, by-products gypsum have proved to be less successful for utilization in API Classes of oilwell cements, because of the greater difficulty in obtaining batch-to-batch consistency in properties like thickening time and slurry rheology. 11 refs., 3 figs., 5 tabs.

  18. 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.

  19. The effect of alternative fuel combustion in the cement kiln main burner on production capacity and improvement with oxygen enrichment.

    OpenAIRE

    Ariyaratne, W.K.Hiromi; Melaaen, Morten Christian; Tokheim, Lars-André

    2013-01-01

    A mathematical model based on a mass and energy balance for the combustion in a cement rotary kiln was developed. The model was used to investigate the impact of replacing about 45 % of the primary coal energy by different alternative fuels. Refuse derived fuel, waste wood, solid hazardous waste and liquid hazardous waste were used in the modeling. The results showed that in order to keep the kiln temperature unchanged, and thereby maintain the required clinker quality, the production capa...

  20. Quantitative Analysis of the Mineralogical Stages of the Clinkers of Portland Cement. Qualitative and Quantitative Analysis, by Infrared Spectroscopy of the Mineralogical Stages of the Clinker of Portland Cement

    Directory of Open Access Journals (Sweden)

    Käsner, Bernd

    1972-09-01

    Full Text Available Not availablePara la determinación cuantitativa de las fases mineralógicas del clinker de cemento portland, tan sólo se emplean el análisis microscópico y el de difracción de rayos X. Ambas técnicas exigen una preparación de muestras muy cuidadosa, lo que lleva bastante tiempo. A causa de estas circunstancias surge el interés de desarrollar un procedimiento con el que se pueda obtener resultados de exactitud y con poco trabajo, basado en la espectroscopia infrarroja. En principio existen dificultades, tanto en el método de trabajo como de interpretación de resultados. Por ejemplo, la formación y composición de las fases del clíñker se hallan sometidas a variaciones; por otra parte, aún no se ha llegado a elaborar un procedimiento para estudio por IR de sistemas que contengan varios componentes inorgánicos en estado sólido. Se ha pensado en la realización previa de análisis elementales, con los que se aclararían los de las fases minerales de los clínkeres, ya que no está aún suficientemente resuelto —a pesar de la importancia que esto representa— el análisis cuantitativo de estas fases.

  1. Minerals of expansive and non-shrinkage sulfomineral cements

    Directory of Open Access Journals (Sweden)

    Samchenko Svetlana V.

    2017-01-01

    Full Text Available Usually to obtain expansive cements sulfoaluminate clinker or mix aluminate clinker with calcium sulfates (gypsum, hemihydrate, anhydrate are used. For these cements ettringite is an important hydration product and kinetic reaction of this phase plays an important role in determinаting performance. The alternative aluminate phases may be ferrite containing ones. This article deals with the composition and properties of solid solution of calcium sulfoaluminate, sulfoferrite and sulfoaluminoferrite cements. It was studied an influence of calcium sulfate on structure and properties of calcium aluminate and ferrite phases, and their stability under high temperatures. Beside that the properties of cements containing these phases were studied. The investigation of hydration and properties of sulfomineral cements shows that ettringite and its analogies are formed in such way to provide expansion and compression of cement stone. Degree of expansion and self-stressing of cement stone depends not only on composition of sulfated minerals but on ratio and types of clinkers. The higher expansion is reached by the use of high alite containing Portland cement clinker together with sulfoaluminate or sulfoalumoferrite one, the lower expansion is reached by addition of sulfoalumoferrite and sulfoferrite clinkers. These cements are classified as self-stressing, expansive or shrinkage-compensating ones depend on the degree of their expansion after 28 days of curing.

  2. 不同分解工艺下磷石膏分解制水泥熟料的LCA研究%LCA Study on the Preparation of Cement Clinker by the Phosphogypsum Decomposition Under Different Decomposition Process

    Institute of Scientific and Technical Information of China (English)

    张杭; 马丽萍; 胡建红; 毛宇; 戴取秀; 谢龙贵

    2013-01-01

    Phosphogypsum was a by-production of the production of wet phosphoric acid,which caused environmental pollution containing water and air pollution.The method of life cycle assessment was used to analyze the test method of circulating fluidized bed reduced and decomposed phosphogypsum to make cement clinker,and it was compared with the traditional method of rotary kiln.The results show that the impact of cement production on environmental load mainly reflected on the consumption of non-generation energy and non-reclaiming source,as well as green house effect.The test method which reduced the impact of the manufacturing process on the environment was proposed.%磷石膏是湿法磷酸生产过程中的副产品,大量的磷石膏废渣可引起水体和空气的环境污染,运用生命周期评价的方法,对循环流化床还原分解磷石膏制水泥熟料试验方法进行分析,并与传统的回转窑方法进行比较.研究结果表明,在工艺过程中的环境负荷主要体现在不可再生资源的消耗、不可再生能源的消耗和温室效应,所提出的试验方法较传统方法可减少工艺过程中对环境负荷的影响.

  3. Preparation of clinker from paper pulp industry wastes.

    Science.gov (United States)

    Buruberri, Leire H; Seabra, M P; Labrincha, J A

    2015-04-01

    The production of paper pulp by the Kraft method generates considerable amounts of wastes. Namely, lime mud generated in the recovery circuit of chemical reagents, biological sludge from the wastewater treatment of wood digestion process and fly ash collected in the fluidized bed combustor used to generate electricity from biomass burning. The final destination of such wastes is an important concern, since environmental regulations are becoming stricter regarding their landfill. Driven by this fact, industries are looking for more sustainable solutions, such as the recycling in distinct products. This work tested these wastes as secondary raw materials to produce clinker/cement that was then experienced in mortar formulations. The first step involved the residues detailed characterization and a generated amounts survey. Then, specific but simple steps were suggested, aiming to facilitate transport and manipulation. Distinct blends were prepared and fired in order to get belitic and Portland clinkers. The Portland clinkers were processed at lower temperatures than the normally used in the industry due to the presence of mineralizing impurities in some wastes. Belite-based cements were used to produce mortars that developed satisfactory mechanical strength and did not reveal signs of deterioration or durability weaknesses.

  4. Sustainable Development of the Cement Industry and Blended Cements to Meet Ecological Challenges

    Directory of Open Access Journals (Sweden)

    Konstantin Sobolev

    2003-01-01

    Full Text Available The world production of cement has greatly increased in the past 10 years. This trend is the most significant factor affecting technological development and the updating of manufacturing facilities in the cement industry. Existing technology for the production of cement clinker is ecologically damaging; it consumes much energy and natural resources and also emits pollutants. A new approach to the production of blended or high-volume mineral additive (HVMA cement helps to improve its ecological compatibility. HVMA cement technology is based on the intergrinding of portland cement clinker, gypsum, mineral additives, and a special complex admixture. This new method increases the compressive strength of ordinary cement, improves durability of the cement-based materials, and - at the same time - uses inexpensive natural mineral additives or industrial by-products. This improvement leads to a reduction of energy consumption per unit of the cement produced. Higher strength, better durability, reduction of pollution at the clinker production stage, and decrease of landfill area occupied by industrial by-products, all provide ecological advantages for HVMA cement.

  5. Sustainable development of the cement industry and blended cements to meet ecological challenges.

    Science.gov (United States)

    Sobolev, Konstantin

    2003-05-05

    The world production of cement has greatly increased in the past 10 years. This trend is the most significant factor affecting technological development and the updating of manufacturing facilities in the cement industry. Existing technology for the production of cement clinker is ecologically damaging; it consumes much energy and natural resources and also emits pollutants. A new approach to the production of blended or high-volume mineral additive (HVMA) cement helps to improve its ecological compatibility. HVMA cement technology is based on the intergrinding of portland cement clinker, gypsum, mineral additives, and a special complex admixture. This new method increases the compressive strength of ordinary cement, improves durability of the cement-based materials, and--at the same time--uses inexpensive natural mineral additives or industrial by-products. This improvement leads to a reduction of energy consumption per unit of the cement produced. Higher strength, better durability, reduction of pollution at the clinker production stage, and decrease of landfill area occupied by industrial by-products, all provide ecological advantages for HVMA cement.

  6. Environmental assessment of sewage sludge as secondary raw material in cement production--a case study in China.

    Science.gov (United States)

    Hong, Jinglan; Li, Xiangzhi

    2011-06-01

    A life cycle assessment was carried out to estimate the environmental impact of sewage sludge as secondary raw material in cement production. To confirm and add credibility to the study, uncertainty analysis was conducted. Results showed the impact generated from respiratory inorganics, terrestrial ecotoxicity, global warming, and non-renewable energy categories had an important contribution to overall environmental impact, due to energy, clinker, and limestone production stages. Also, uncertainty analysis results showed the technology of sewage sludge as secondary raw material in cement production had little or no effect on changing the overall environmental potential impact generated from general cement production. Accordingly, using the technology of sewage sludge as secondary raw material in cement production is a good choice for reducing the pressure on the environment from dramatically increased sludge disposal. In addition, increasing electricity recovery rate, choosing natural gas fired electricity generation technology, and optimizing the raw material consumption in clinker production are highly recommended to reduce the adverse effects on the environment.

  7. Energy saving cement production by grain size optimisation of the raw meal

    Directory of Open Access Journals (Sweden)

    B. Simons

    Full Text Available The production of cement clinker is an energy consuming process. At about 50% of the energy is associated with grinding and milling of the raw meal, that normally is in the range 100% <200 μm with 90% <90 μm. Question: is it possible to use coarser components of the raw meal without reducing the clinker quality. With synthetic raw meals of various grain sizes the clinker formation was studied at static (1100 - 1450°C and dynamic conditions (heating microscope. A routine to adjust the grain size of the components for industrial raw meals is developed. The fine fraction <90 μm should mainly contain the siliceous and argileous components, whereas the calcitic component can be milled separately to a grain size between 200-500 μm, resulting in lower energy consumption for milling. Considering the technical and economical realizability the relation fine/coarse should be roughly 1:1. The energy for milling can be reduced significantly, that in addition leads to the preservation of natural energy resources.

  8. Wide-scale utilization of MSWI fly ashes in cement production and its impact on average heavy metal contents in cements: The case of Austria.

    Science.gov (United States)

    Lederer, Jakob; Trinkel, Verena; Fellner, Johann

    2017-02-01

    A number of studies present the utilization of fly ashes from municipal solid waste incineration (MSWI) in cement production as a recycling alternative to landfilling. While there is a lot of research on the impact of MSWI fly ashes utilization in cement production on the quality of concrete or the leaching of heavy metals, only a few studies have determined the resulting heavy metal content in cements caused by this MSWI fly ashes utilization. Making use of the case of Austria, this study (1) determines the total content of selected heavy metals in cements currently produced in the country, (2) designs a scenario and calculates the resulting heavy metal contents in cements assuming that all MSWI fly ashes from Austrian grate incinerators were used as secondary raw materials for Portland cement clinker production and (3) evaluates the legal recyclability of demolished concretes produced from MSWI fly ash amended cements based on their total heavy metal contents. To do so, data from literature and statistics are combined in a material flow analysis model to calculate the average total contents of heavy metals in cements and in the resulting concretes according to the above scenario. The resulting heavy metal contents are then compared (i) to their respective limit values for cements as defined in a new technical guideline in Austria (BMLFUW, 2016), and (ii) to their respective limit values for recycling materials from demolished concrete. Results show that MSWI fly ashes utilization increases the raw material input in cement production by only +0.9%, but the total contents of Cd by +310%, and Hg, Pb, and Zn by +70% to +170%. However these and other heavy metal contents are still below their respective limit values for Austrian cements. The same legal conformity counts for recycling material derived from concretes produced from the MSWI fly ash cements. However, if the MSWI fly ash ratio in all raw materials used for cement production were increased from 0.9% to 22

  9. Design of Minerals Composition in Cement Clinker Containing Clacium Sulphoaluminate%含硫铝酸钙矿物硅酸盐水泥熟料矿物组成设计

    Institute of Scientific and Technical Information of China (English)

    马素花; 沈晓冬

    2009-01-01

    The influence of additive on the burning and minerals composition of cement clinker containing calcium sulphoaluminate were researched by chemical analysis and X-Ray diffraction.The results show that the additive must be added in the raw meal for the preparation of the clinker containing calcium sulphoaluminate. The suitable amount of additive can decrease the burning temperature of the clinker containing calcium sulphoaluminate, promote the adopt of f-CaO and improve the burnability of the raw meal. At the relative low temperature (1300 ℃ or 1350 ℃), the clinker containing calcium sulphoaluminate can be preparaed successfully.%采用化学分析、X射线衍射等测试手段研究了掺杂离子对含硫铝酸钙(C_4A_3(S))硅酸盐水泥熟料烧成及矿物组成的影响.研究结果表明:要制备含C_4A_3(S)矿物硅酸盐水泥熟料,应在生料中掺入合适的杂质离子;适量的掺杂离子能降低含C_4A_3(S)矿物硅酸盐水泥熟料的烧成温度,大幅度促进熟料中f-CaO的吸收,改善生料的易烧性,在低温煅烧温度(1300 ℃或1350 ℃)下成功制备了含C_4A_3(S)矿物硅酸盐水泥熟料.

  10. Socio-environmental Impacts Associated with Burning Alternative Fuels in Clinker Kilns

    Directory of Open Access Journals (Sweden)

    F. B. Mainier

    2013-08-01

    Full Text Available The pollutants found in emissions from cement plants depend on the processes used and the operation of the clinker kilns. Another crucial aspect concerns the characteristics of raw materials and fuels. The intensive use of fuels in rotary kilns of cement plants and the increasing fuel diversification, including fuels derived from coal and oil, from a multitude of industrial waste and from biomass, charcoal and agricultural waste (sugarcane bagasse, rice husk, is increasing the possibilities of combinations or mixtures of different fuels, known as blends. Thus, there are socio-environmental impacts associated with the burning of alternative fuels in clinker kilns. In view of the growing trend of entrepreneurs who want to target the waste produced in their unit and of the owners of the cement plants who want to reduce their production costs by burning a waste with lower cost than conventional fuels, it is necessary to warn that a minimum level of environmental care should be followed regarding these decisions. It is necessary to monitor the points of emission from cement kilns and in the wider area influenced by the plant, in order to improve environmental quality. Laboratory studies of burning vulcanised rubber contaminated with arsenic simulate the burning of used tyres in cement clinker kilns producing SO2 and As2O3.

  11. INFLUENCE OF BARIUM OXIDE ADDITIONS ON PORTLAND CLINKER

    National Research Council Canada - National Science Library

    Zezulova, Anezka

    2016-01-01

    ... that the radiation shielding capability of cement can be improved by incorporation of barium. This work deals with the influence of barium oxide, added in the form of barium carbonate and sulphate, on the formation and properties of Portland clinker...

  12. Problems with low-temperature clinkers

    Energy Technology Data Exchange (ETDEWEB)

    Sychev, M.M.; Tandilova, K.B.; Minkina, V.N.

    1987-07-20

    In the cement industry, there are real problems connected with reducing the fuel/energy consumption and producing high-strength and rapid setting cements. A series of physicochemical examinations and pilot plant trials have shown that the use of BaSO/sub 4/ + CaSO/sub 4/ as a compound additive (barium-containing waste + gypsum) makes it possible to prepare a belite clinker at a temperature of 1250/sup 0/C; the BaSO/sub 4/ + CaSO/sub 4/ additive stabilizes the dicalcium silicate in the ..cap alpha..'-modification; introduction of the compound additive into the belite raw material mixture leads to the formation of hydraulically active minerals in the clinker-calcium sulfoaluminate, monocalcium aluminate, and ..cap alpha..'-C/sub 2/S, which in combination with alite ensure that a high-activity belite clinker is obtained at low burning temperatures.

  13. Alternative Fuels in Cement Production

    DEFF Research Database (Denmark)

    Larsen, Morten Boberg

    The substitution of alternative for fossil fuels in cement production has increased significantly in the last decade. Of these new alternative fuels, solid state fuels presently account for the largest part, and in particular, meat and bone meal, plastics and tyre derived fuels (TDF) accounted...... of the fuel heating value. In addition, the devolatilization time of alternative fuels cannot be neglected in kiln system process analyses, as these fuels are typically in the cm-size with devolatilization times in the order of minutes. The devolatilization characteristics of large particles of tyre rubber...... time, where increased particle size increased the devolatilization time. Model analyses demonstrated that the overall devolatilization kinetics of large particles of tyre rubber is mainly controlled by heat transfer and intrinsic pyrolysis kinetics, whereas mass transfer has negligible influence...

  14. Plant Test of Industrial Waste Disposal in a Cement Kiln

    Institute of Scientific and Technical Information of China (English)

    刘阳生; 韩杰; 等

    2003-01-01

    Destruction of industrial waste in cement rotary kilins(CRKs) is an alternative technology for the treatment of certain types of industrial waste(IW).In this paper,three typical types of industrial wastes were co-incinerated in the CRK at Beijing Cement Plant to determine the effects of waste disposal(especially solid waste disposal )on the quality of clinker and the concentration of pollutants in air emission.Experimental results show that(1) waste disposal does not affect the quality of clinker and fly ash,and fly ash after the IW disposal can still be used in the cement production,(2) heavy metals from IW are immobilized and stabilized in the clinker and cement,and (3) concentration of pollutants in air emission is far below than the permitted values in the China National Standard-Air Pollutants Emission Standard(GB 16297-1996).

  15. 掺SO3硅酸盐水泥熟料中矿物相形成过程研究%Phase Formation of SO3 Doped Portland Cement Clinker

    Institute of Scientific and Technical Information of China (English)

    许捷; 黎学润; 沈晓冬

    2013-01-01

    Impact of the addition of 3% SO3 on the formation of cement clinker minerals in industrials clinker was investigated. Variation of the C4A3 $ during sintering process was taken into account. Sintering process of the cement clinker was investigated with DSC-TG, X-ray diffraction and microscopic analysis. Results showed that with a higher SO3 content existed,C4A3 $ could formed at 1050 ℃ and decomposed to C3A and C $ from 1290 ℃ ; C3S formed after 1350 ℃ and f-CaO content dropped to 1% at 1450 ℃. The final clinker had 6.2% C4A3 $ . C4A3 $ decomposed completely when held for 0.5 h at 1450 ℃. Calculation of the theoretical mineral formation was in agreement with the above conclusions.%研究了工业原料配料生料中SO3含量为3%时,熟料主要矿物形成过程与含量变化.重点观察了C4A3($)(硫铝酸钙)在烧成过程中的变化情况.借助DSC-TG,X射线衍射法及岩相分析对水泥熟料的烧成过程进行了研究.结果表明,熟料中,C4A3($)在1050℃时即可形成,1290℃开始分解为C3A和C($);1350℃后C3S开始大量形成,1450℃取出急冷,f-CaO的含量小于1%,熟料中有6.2%C4A3($).1450℃保温不同0.Sh后,C4A3($)完全分解.对熟料矿物形成量进行理论计算,结果与实验结论一致.

  16. INFLUENCE OF ZnO ON FORMATION AND PROPERTIES FOR HIGH CEMENTING CLINKER%氧化锌对高胶凝性水泥熟料矿物形成及强度的影响

    Institute of Scientific and Technical Information of China (English)

    马素花; 沈晓冬; 黄叶平; 龚学萍; 钟白茜

    2005-01-01

    采用工业原料配料,对以硅酸三钙(C3S,C=CaO,S=SiO2)、硫铝酸钙(C4A3 S,C=CaO,A=Al2O3,S=SO42-)为主导矿物的含C4A3S矿物硅酸盐水泥熟料的矿物形成及其强度进行了研究.借助X射线衍射和热重-差热分析研究了矿物形成过程;探讨了微量元素ZnO对熟料性能的影响及在熟料体系中的固溶情况.研究结果表明:生料中掺入ZnO可使C4A3(-/S)和C3S等矿物通过低温反应形成,共存于同一熟料体系中,并可提高熟料的强度;过高的ZnO含量亦会降低C4A3 S矿物的分解温度.%The formation and strength of Portland cement clinker containing calcium sulphoaluminate ( C4 A3 (-/S), C= CaO, A=Al2O3, (-/S)= SO42- ), which was synthesized with industrial reagents as raw materials, were studied. The process of mineral for mation was analyzed by X-ray diffraction and thermogravimetric - differential scanning calorimetry. The influence of ZnO on the properties of clinker and solid solutions were discussed. The results show that tricalcium silicate (C3 S, S= SiO2 ) and calcium sulphoaluminate ( C4 A3(-/S)) minerals can form and coexist in clinkers sintered at low temperature by the addition of ZnO to the raw material, and increase the strength of Portland cement clinker containing C4 A3(-/S). The decomposition temperature of C4 A3(-/S) can be lowered by the addition of excessive ZnO into the raw materials.

  17. Language Select Language Article Tools Print this article Indexing metadata How to cite item Email this article Email the author Information For Authors For Librarians p-ISSN: 2088-4842 e-ISSN: 2442-8795 Home > Vol 15, No 1 > Putri Penjadwalan Cement Mill Berbasis Minimasi Faktor Klinker dalam Proses Pembilasan dan Impor Klinker

    Directory of Open Access Journals (Sweden)

    Nilda Tri Putri

    2016-04-01

    Full Text Available PT Semen Padang is one of the cement companies in indonesia. Cement production influenced by the number of demand, raw materials and the number of available machine. The number of demand increases with a corporate capacity which keep the company had to set an optimal production schedule. Scheduling production should be followed by the availability of raw materials (clinker. The number of clinker required influenced by the number of demands and clinker elapsed to the flushing process. Flushing process happen if the transition products produced from Non OPC to a product OPC, for one flushing process causes clinker consumption 7% more that the existing capacity decreases. Deficient in capacity covered by importing clinker which causes high cost production. So, it necessary to make cement mill schedule by minimize flushing process, so clinker that will be used become optimized. Steps that will be done in this study began with the survey system, identify problems, and data collection. Data collected are machine cement mill and kiln capacity, demands, and flushing process. Then designed a formulation model that is minimize clinker factor and the number of clinker imports needed, so that obtained scheduling machine cement mill to produce OPC and Non OPC. Results obtained by reducing the number of flushing process because the cement mill designed to producing one type of product per day, so the flushing process could happen if there is transition cement production Non OPC on the day-i to cement OPC on the day i+1. Cement OPC produced by indarung II, III, and V. Indarung IV only produced cement Non OPC, so the flushing process happened in Indarung II, III, and V.

  18. Trace elements based classification on clinkers. Application to Spanish clinkers

    Directory of Open Access Journals (Sweden)

    Tamás, F. D.

    2001-12-01

    Full Text Available The qualitative identification to determine the origin (i.e. manufacturing factory of Spanish clinkers is described. The classification of clinkers produced in different factories can be based on their trace element content. Approximately fifteen clinker sorts are analysed, collected from 11 Spanish cement factories to determine their Mg, Sr, Ba, Mn, Ti, Zr, Zn and V content. An expert system formulated by a binary decision tree is designed based on the collected data. The performance of the obtained classifier was measured by ten-fold cross validation. The results show that the proposed method is useful to identify an easy-to-use expert system that is able to determine the origin of the clinker based on its trace element content.

    En el presente trabajo se describe el procedimiento de identificación cualitativa de clínkeres españoles con el objeto de determinar su origen (fábrica. Esa clasificación de los clínkeres se basa en el contenido de sus elementos traza. Se analizaron 15 clínkeres diferentes procedentes de 11 fábricas de cemento españolas, determinándose los contenidos en Mg, Sr, Ba, Mn, Ti, Zr, Zn y V. Se ha diseñado un sistema experto mediante un árbol de decisión binario basado en los datos recogidos. La clasificación obtenida fue examinada mediante la validación cruzada de 10 valores. Los resultados obtenidos muestran que el modelo propuesto es válido para identificar, de manera fácil, un sistema experto capaz de determinar el origen de un clínker basándose en el contenido de sus elementos traza.

  19. Feasibility study of the Portland cement industry waste for the reduction of energy consumption

    Energy Technology Data Exchange (ETDEWEB)

    Bernardo, Ana Carla de Souza Masselli; Junqueira, Mateus Augusto F. Chaib; Jorge, Ariosto Bretanha; Silva, Rogerio Jose da [Universidade Federal de Itajuba (UNIFEI), MG (Brazil). Institute of Mechanical Engineering]. E-mails: anacarlasz@unifei.edu.br; mateus_afcj@yahoo.com.br; ariosto.b.jorge@unifei.edu.br; rogeriojs@unifei.edu.br

    2008-07-01

    The Portland cement industry demand a high specific consumption of energy for the production of the clinker. The energy consumption for clinker production varies between 3000 and 5300 kJ/kg of produced clinker. The clinker is produced by blending of different raw materials in order t o achieve precise chemical proportions of lime, silica, alumina and iron in the finished product and by burning them at high temperatures. The Portland cement is a mixture of clinker, gypsum and other materials. Due to need of high temperatures, tradition ally the fuels used in the cement industry are mineral coal, fuel oil, natural gas and petroleum coke. The fuel burning in high temperature leads to the formation of the pollutant thermal NOx. The level of emissions of this pollutant is controlled by environmental law, thus the formation of pollutants in process need be controlled. Moreover, industrial waste has been used by Portland cement industries as a secondary fuel through a technique called co -processing. Materials like waste oils, plastics, waste tyres and sewage sludge are often proposed as alternative fuels for the cement industry. The residues can be introduced as secondary fuel or secondary raw material. For energy conservation in the process, mineralizers are added during the process production of the clinker. The mineralizers promote certain reactions which decrease the temperature in the kiln and improve the quality of the clinker. The adequate quantity of constituents in production process is complex, for maintain in controlled level, the quality of final product, the operational conditions of kiln, and the pollutant emissions. The purpose of the present work is to provide an analysis of an optimal production point through of the optimization technique considering, the introduction of the fuels, industrial wastes as secondary fuels, and raw materials, for the reduction of energy in the process of Portland cement production. (author)

  20. Carbonate Looping for De-Carbonization of Cement Plants

    OpenAIRE

    2011-01-01

    Cement industry is one of the largest emitter of CO2 other than power generation plants, which includes the emissions from combustion of fuel and also from calcination of limestone for clinker production. In order to reduce CO2 emissions from the cement industry an effective an economically feasible technology is to be developed. The carbonate looping process is a promising technology, which is particularly suitable for the cement industry as limestone could be used for capture and release of...

  1. Clasifícación de clinkeres basándose en sus elementos traza. Aplicación a clinkeres españoles

    OpenAIRE

    Tamás, F. D.; Abonyi, J.; Puertas, F.

    2001-01-01

    [EN]The qualitative identification to determine the origin (i.e. manufacturing factory) of Spanish clinkers is described. The classification of clinkers produced in different factories can be based on their trace element content. Approximately fifteen clinker sorts are analysed, collected from 11 Spanish cement factories to determine their Mg, Sr, Ba, Mn, Ti, Zr, Zn and V content. An expert system formulated by a binary decision tree is designed based on the collected data. The perfo...

  2. Leachable characteristics of arsenical borogypsum wastes and their potential use in cement production.

    Science.gov (United States)

    Alp, Ibrahim; Deveci, Haci; Süngün, Y Halil; Yazici, Ersin Y; Savaş, Mehmet; Demirci, Songül

    2009-09-15

    In this study; the potential use of arsenical borogypsum wastes (ABW) as a set retarder in cement industry was investigated. The comparative performances of arsenical borogypsum wastes (ABW) and natural gypsum samples (NG1 and NG2) at different proportions in the range of 3-8 wt % were tested based on compressive strength over 1, 2, 7, and 28 days and setting times. The use of ABW was observed to lead to a somewhat slower rate of development of strength of the mortar samples than those of NG1 and NG2 during the curing period of 7 days. This is the indication of the effectiveness of ABW as a set retarder. The 28-day compressive strength of mortars tended to decrease with the addition or increasing the proportion of ABW, beyond 5 wt % in particular. The data for setting times of the cement products confirmed set retarding characteristics of ABW with an initial setting time of 90-120 min at 3-5 wt % dosage, which conforms to the desired setting time of > or = 60 min for CEM I (42.5 N) type cement (TS EN 197-1). Leachability tests (TCLP and SPLP) have also shown that ABW can be classified as a nonhazardous waste; but it can readily release metals such as As and Mn, in particular, whereas the mortar samples containing ABW-cement clinker present no environmental concern with its remarkably reduced leachability.

  3. Alternative Fuels in Cement Production

    OpenAIRE

    2007-01-01

    Substitutionen af fossilt med alternativt brændsel i cement produktionen er steget betydeligt i den sidste dekade. Af disse nye alternative brændsler, udgør de faste brændsler p.t. den største andel, hvor kød- og benmel, plastic og dæk i særdeleshed har været de alternative brændsler der har bidraget med mest alternativ brændsels energi til den tyske cement industri. De nye alternative brændsler er typisk karakteriseret ved et højt indhold af flygtige bestanddele og adskiller sig typisk fra t...

  4. Influence of Cellulose Ethers on Hydration Products of Portland Cement

    Institute of Scientific and Technical Information of China (English)

    MA Baoguo; OU Zhihua; JIAN Shouwei; XU Rulin

    2011-01-01

    Cellulose ethers are widely used to mortar formulations, and it is significant to understand the interaction between cellulose ethers and cement pastes. FT-IR spectra, thermal analysis and SEM are used to investigate hydration products in the cement pastes modified by HEMC and HPMC in this article. The results show that the hydration products in modified cement pastes were finally identical with those in the unmodified cement paste, but the major hydration products, such as CH (calcium hydroxide), ettringite and C-S-H, appeared later in the modified cement pastes than in the unmodified cement paste. The cellulose ethers decrease the outer products and increase inner products of C-S-H gels. Compared to unmodified cement pastes, no new products are found in the modified cement pastes in the present experiment. The HEMC and HPMC investigation shows almost the same influence on the hydration products of Portland cement.

  5. Calculation of the C3A Percentage in High Sulfur Clinker

    Directory of Open Access Journals (Sweden)

    Sayed Horkoss

    2010-01-01

    Full Text Available The aim of this paper is to clarify the influence of the clinker SO3 on the amount of C3A. The calculation of the cement phases percentages is based on the research work, Calculation of the Compounds in Portland Cement, published by Bogue in 1929 .The usage of high sulphur fuels, industrial wastes, and tires changes completely the working condition of Bogue because the assumed phase compositions may change. The results prove that increasing the amount of SO3 in the low alkali clinker decreases the percentages of C3A due to the high incorporation of alumina in the clinker phases mainly C2S and C3S. The correlation is linear till the clinker SO3 reaches the 2%. Over that the influence of the clinker SO3 became undetectable. A new calculation method for the determination of the C3A in the high sulphur and low alkali clinker was proposed.

  6. 水泥熟料及碱盐对方镁石-镁铝尖晶石砖的侵蚀行为%Corrosion behavior of cement clinker and alkali salts to periclase-spinel bricks

    Institute of Scientific and Technical Information of China (English)

    章道运; 肖国庆; 蒋明学; 师素环

    2012-01-01

    Fused magnesia and fused magnesium aluminate spinel (MA) were used to prepare the peri-clase-MA bricks for corrosion resistance tests at different temperatures. The influences of cement clinker and alkali salts (K2SO4 and KCI) on the chemical composition, mineral phase and microstructure of peri-clase-MA brick were researched to characterize their corrosion behavior to periclase-MA bricks. The results show that; (1) the clinker penetration into the bricks at high temperatures is the main corrosion process during which the clinker corrodes M2S in the matrix and MgO in the brick forming monticellite (CaO · MgO · SiO2,CMS) and consequently M2S and MgO dissolve continuously,a dense deteriorative layer forms;the higher the temperature and the more obvious the penetration and corrosion;(2)through the liquid penetration and gas diffusion,the alkali salts react with the impurities in the brick forming new gases to emit;the brick surface becomes loose because of chemical corrosion of alkali salts,and the deeper layer of the brick becomes dense due to the sediment of residual alkalis;(3) in the actual use,alkali salts corrode periclase and binding phases in the brick resulting in the loose high temperature layer which makes much cement clinker corrodes and penetrates forming dense deteriorative layer; in low temperature layer the crystallization and sediment of alkali salts make the dense deteriorative layer thicker and this layer will result in the severe structure spalling of periclase-MA bricks when suffering temperature fluctuation.%对以电熔镁砂、电熔镁铝尖晶石为原料制备的方镁石-镁铝尖晶石砖进行了不同温度的抗侵蚀试验,研究了水泥熟料及碱盐(K2SO4、KCl)对方镁石-镁铝尖晶石砖的化学组成、矿物组成及显微结构的影响,从而研究其对方镁石-镁铝尖晶石砖的侵蚀行为.结果表明:1)水泥熟料对方镁石-镁铝尖晶石砖的侵蚀过程主要是向砖内渗透,侵

  7. Clinker mineral hydration at reduced relative humidities

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede

    1998-01-01

    This report deals with gas phase hydration of pure cement clinker minerals at reduced relative humidities. This is an important subject in relation to modern high performance concrete which may self-desiccate during hydration. In addition the subject has relevance to storage stability where...... prehydration may occur. In the report both theoretical considerations and experimental data are presented. It is suggested that the initiation of hydration during water vapour exposure is nucleation controlled....

  8. Study on Clinker Heat Transfer Model of Cement Cooler Based on Operator Splitting Method%基于剖开算子法的水泥篦冷机熟料换热模型研究

    Institute of Scientific and Technical Information of China (English)

    郝晓辰; 范新丰; 刘彬

    2013-01-01

    In this article the high-temperature cement clinker physical model and mathematical model are built up based on the porous media seepage heat transfer theory. According to the character of the mathematical model, this article brings forth using the operator splitting method to solve the mathematical model. The correctness of the heat transfer model is proved through the simulation experiment and the temperature variation regular pattern is given. The simulation results can accurately reflect the physical truth. Based on the above, this article analyses the clinker' s cooling effect of the fluid air speed and provides the theoretic guidance for the optimization design of the air feeding.%本文根据多孔介质渗流换热理论建立了高温水泥熟料的物理换热模型和数学换热模型,并针对高温水泥熟料数学换热模型的特点,提出采用剖开算子法对其进行求解.并通过仿真实验验证了该换热模型的正确性,给出了换热过程中熟料和气体的温度变化规律,仿真实验结果显示该数学换热模型能比较准确的反映实际情况,在此基础上分析了篦下风速对熟料冷却效果的影响,为篦冷机优化配风设计提供了理论指导.

  9. Portland clinker production with carbonatite waste and tire-derived fuel: crystallochemistry of minor and trace elements

    Directory of Open Access Journals (Sweden)

    F. R. D. Andrade

    2014-12-01

    Full Text Available This paper presents results on the composition of Portland clinkers produced with non-conventional raw-materials and fuels, focusing on the distribution of selected trace elements. Clinkers produced with three different fuel compositions were sampled in an industrial plant, where all other parameters were kept unchanged. The fuels have chemical fingerprints, which are sulfur for petroleum coke and zinc for TDF (tire-derived fuel. Presence of carbonatite in the raw materials is indicated by high amounts of strontium and phosphorous. Electron microprobe data was used to determine occupation of structural site of both C3S and C2S, and the distribution of trace elements among clinker phases. Phosphorous occurs in similar proportions in C3S and C2S; while considering its modal abundance, C3S is its main reservoir in the clinker. Sulfur is preferentially partitioned toward C2S compared to C3S. Strontium substitutes for Ca2+ mainly in C2S and in non-silicatic phases, compared to C3S.

  10. INFLUENCE OF BARIUM OXIDE ADDITIONS ON PORTLAND CLINKER

    Directory of Open Access Journals (Sweden)

    Anezka Zezulova

    2016-12-01

    Full Text Available Nowadays, nuclear power plants are widespread around the world and research is of great interest. Together with nuclear research, shielding of different types of radiation is an important current topic of research aiming at their safety. Portland cement has been an elementary building material for centuries. Since barium is very efficient in shielding different types of radiation, it can be assumed that the radiation shielding capability of cement can be improved by incorporation of barium. This work deals with the influence of barium oxide, added in the form of barium carbonate and sulphate, on the formation and properties of Portland clinker. The structure of burnt clinkers and the ratio of clinker phases were studied by polarizing microscopy and by X-ray diffraction. With increasing barium content, the alite-belite ratio decreases and the content of free lime gradually increases. Moreover, sulphates induce the growth of alite crystals. The ability of barium to be a part of the clinker minerals was observed by scanning electron microscopy. Belite and clinker melt contain the highest amount of barium, but aggregates of barium oxide are formed in the clinker melt. Furthermore, the rate of alite crystallization was studied under isothermal conditions.

  11. [Environment load from China's cement production].

    Science.gov (United States)

    Zhu, Tian-le; He, Wei; Zeng, Xiao-lan; Huang, Xin; Ma, Bao-guo

    2006-10-01

    Based on the life-cycle theory, a quantitative evaluation of the environment load caused by cement manufacturing in China was carried out with the application of the CML. environmental impact assessment method. The results show that global warming potential, energy depletion potential and abiotic depletion potential make the main contribution to the environment impact, their environmental loads corresponding to identical environmental impact sorts being 2.76%, 2.34% and 1.39% of the overall load of the whole world, respectively. In 2004, the environment load from cement manufacturing in China is roughly 1.28% of the overall load of the whole world, in which the environmental loads from the shaft kiln processing, wet rotary processing and new-type dry processing being 0.84%, 0.12% and 0.32%, respectively. And it can be reduced to about 1% by replacing backward production processes with the dry method production process.

  12. The effect of statistical analytical measurement variations on the plant control parameters and production costs in cement manufacturing – a case study

    Directory of Open Access Journals (Sweden)

    A. D. Love

    2010-01-01

    Full Text Available Raw materials used in cement manufacturing normally have varying chemical compositions and require regular analyses for plant control purposes. This is achieved by using several analytical instruments, such as XRF and ICP. The values obtained for the major elements Ca, Si, Fe and Al, are used to calculate the plant control parameters Lime Saturation Factor (LSF, Silica Ratio (SR and Alumina Modulus (AM. These plant control parameters are used to regulate the mixing and blending of various raw meal components and to operate the plant optimally. Any errors and large fluctuations in these plant parameters not only influence the quality of the cement produced, but also have a major effect on the cost of production of cement clinker through their influence on the energy consumption and residence time in the kiln. This paper looks at the role that statistical variances in the analytical measurements of the major elements Ca, Si, Fe and Al can have on the ultimate LSF, SR and AM values calculated from these measurements. The influence of too high and too low values of the LSF, SR and AM on clinker quality and energy consumption is discussed, and acceptable variances in these three parameters, based on plant experiences, are established. The effect of variances in the LSF, SR and AM parameters on the production costs is then analysed, and it is shown that variations of as large as 30% and as little as 5% can potentially occur. The LSF calculation incorporates most chemical elements and therefore is prone to the largest number of variations due to statistical variances in the analytical determinations of the chemical elements. Despite all these variations in LSF values they actually produced the smallest influence on the production cost of the clinker. It is therefore concluded that the LSF value is the most practical parameter for plant control purposes.

  13. On thermal analysis of temperature derating at high-temperatuer cement clinker silo%高温水泥熟料筒仓进行热分析温度折减探究

    Institute of Scientific and Technical Information of China (English)

    许志争

    2016-01-01

    以某水泥熟料筒仓为例,对仓壁稳态传热和仓顶散热两种温度传递过程进行了研究探讨,在现有算法的基础上,结合有限元的计算结果,提出了一种可行的温度折减解决方案,确保筒仓设计的安全性和经济性。%Taking some cement clinker silo as the example,the paper researches the temperature transmission process of the silo steady-state heat transfer and silo top heat dissipation,and puts forward the feasible the temperature derating solution by combining with the calculation results of the finite element based on the current calculation method,so as to ensure the safety and money-saving of the silo design.

  14. Research on the characteristics of hydration of cement intermixed by the clinkers made in rotary kiln and shaft kiln%回转窑与立窑熟料混合配制水泥的水化特性研究

    Institute of Scientific and Technical Information of China (English)

    梁英; 程德铭; 冯庆革; 李浩璇

    2001-01-01

    The characteristics of hydration of cement intermixed by the clinkers made in rotary kiln and shaft kiln was studied under the same hydration condition through the analyses of hydration degree, chemical composition of liquid phase, XRD, DTA and SEM etc.. The results indicate that the hydration rate of the intermixed clinker at 1d was accelerated instead of being the simple sum of that of the starting clinkers. The intermix of cement did change the morphology of the hydrates while keeping the same types of hydrates. More needle and fibrous hydrates produced during the 1d hydration.%在相同的水化条件下,通过水化程度分析、水化液相分析、 XRD、 DTA和 SEM等方法研究了回转窑与立窑熟料混合配制的水泥的水化特性。结果表明,回转窑与立窑熟料混合后,其 1d水化速率并非两种水泥水化速率的简单加权,而是有明显加快;水泥浆体中的水化产物种类未改变,但改善了水化产物的形貌, 1d水泥浆体中生成了较多的针状和纤维状水化产物。

  15. Early Stage Hydration Process of Cementitious Material Prepared with Red Mud, Slag, Gypsum and Small Smounts of Cement Clinker%赤泥-矿渣-石膏-少熟料胶凝材料的初期水化过程

    Institute of Scientific and Technical Information of China (English)

    祝丽萍; 倪文; 高术杰; 王中杰; 张玉燕

    2012-01-01

    赤泥-矿渣-石膏-少熟料胶凝材料在胶结充填过程中表现出良好的保水性及早强、高强等性能,可以作为充填专用胶结剂.本文综合净浆试块的凝结时间、强度发展以及扫面电镜下的微观结构,分析了材料的初期水化过程,并采用XPS研究了不同元素之间旧组合分解和新组合的形成.结果表明水化3h时体系生成Ca(OH)2和凝胶类物质,这些水化产物使得浆体凝结硬化.4h后矿渣中的部分硅氧四面体参与反应,缩聚成了聚合度较高的硅酸盐矿物,净浆试块产生强度.水化6h后,S2 p3/2的结合能大幅增长,体系生成了较多的硫酸盐矿物,它们对强度的发展起到了较大作用.%The cementitious material prepared with red mud, ground granulated blast furnace slag ( GGBS) , flue gas desulfurization gypsum ( FGDG) and a small amount of cement clinker obtained good performances in water-retention, early strength and high strength when it used for cemented backfilling. This material can be used as special cement for backfilling. The early stage hydration of the material was analyzed through the setting time, strength development and microstructure. The decomposition of old system and the formation of the new mineral were also studied by X-ray photoelectron spectroscopy (XPS). Results show that Ca(0H)2 and gels formed at 3 h after hydration, resulting in the setting and hardening for the cement paste. The samples obtained strength at 4 h, which is attributed to the formation of silicates with higher polymerization degree, which condensed from oxygen-silicon tetrahedron. At 6 h, the binding energy of S2 p3/2 increased suddenly, and some sulfate minerals formed, which made a great contribution to the rise of strength.

  16. 水泥窑处理工业废物的工厂实验研究%Plant Test of Industrial Waste Disposal in a Cement Kiln

    Institute of Scientific and Technical Information of China (English)

    刘阳生; 韩杰; 白庆中

    2003-01-01

    Destruction of industrial waste in cement rotary kilns (CRKs) is an alternative technology for thetreatment of certain types of industrial waste (IW). In this paper, three typical types of industrial wastes wereco-incinerated in the CRK at Beijing Cement Plant to determine the effects of waste disposal (especially solid wastedisposal) on the quality of clinker and the concentration of pollutants in air emission. Experimental results showthat (1) waste disposal does not affect the quality of clinker and fly ash, and fly ash after the IW disposal can still beused in the cement production, (2) heavy metals from IW are immobilized and stabilized in the clinker and cement,and (3) concentration of pollutants in air emission is far below than the permitted values in the China NationalStandard-Air Pollutants Emission Standard (GB 16297-1996).

  17. Reduced carbon emission estimates from fossil fuel combustion and cement production in China

    Science.gov (United States)

    Liu, Zhu; Guan, Dabo; Wei, Wei; Davis, Steven J.; Ciais, Philippe; Bai, Jin; Peng, Shushi; Zhang, Qiang; Hubacek, Klaus; Marland, Gregg; Andres, Robert J.; Crawford-Brown, Douglas; Lin, Jintai; Zhao, Hongyan; Hong, Chaopeng; Boden, Thomas A.; Feng, Kuishuang; Peters, Glen P.; Xi, Fengming; Liu, Junguo; Li, Yuan; Zhao, Yu; Zeng, Ning; He, Kebin

    2015-08-01

    Nearly three-quarters of the growth in global carbon emissions from the burning of fossil fuels and cement production between 2010 and 2012 occurred in China. Yet estimates of Chinese emissions remain subject to large uncertainty; inventories of China's total fossil fuel carbon emissions in 2008 differ by 0.3 gigatonnes of carbon, or 15 per cent. The primary sources of this uncertainty are conflicting estimates of energy consumption and emission factors, the latter being uncertain because of very few actual measurements representative of the mix of Chinese fuels. Here we re-evaluate China's carbon emissions using updated and harmonized energy consumption and clinker production data and two new and comprehensive sets of measured emission factors for Chinese coal. We find that total energy consumption in China was 10 per cent higher in 2000-2012 than the value reported by China's national statistics, that emission factors for Chinese coal are on average 40 per cent lower than the default values recommended by the Intergovernmental Panel on Climate Change, and that emissions from China's cement production are 45 per cent less than recent estimates. Altogether, our revised estimate of China's CO2 emissions from fossil fuel combustion and cement production is 2.49 gigatonnes of carbon (2 standard deviations = +/-7.3 per cent) in 2013, which is 14 per cent lower than the emissions reported by other prominent inventories. Over the full period 2000 to 2013, our revised estimates are 2.9 gigatonnes of carbon less than previous estimates of China's cumulative carbon emissions. Our findings suggest that overestimation of China's emissions in 2000-2013 may be larger than China's estimated total forest sink in 1990-2007 (2.66 gigatonnes of carbon) or China's land carbon sink in 2000-2009 (2.6 gigatonnes of carbon).

  18. Reduced carbon emission estimates from fossil fuel combustion and cement production in China.

    Science.gov (United States)

    Liu, Zhu; Guan, Dabo; Wei, Wei; Davis, Steven J; Ciais, Philippe; Bai, Jin; Peng, Shushi; Zhang, Qiang; Hubacek, Klaus; Marland, Gregg; Andres, Robert J; Crawford-Brown, Douglas; Lin, Jintai; Zhao, Hongyan; Hong, Chaopeng; Boden, Thomas A; Feng, Kuishuang; Peters, Glen P; Xi, Fengming; Liu, Junguo; Li, Yuan; Zhao, Yu; Zeng, Ning; He, Kebin

    2015-08-20

    Nearly three-quarters of the growth in global carbon emissions from the burning of fossil fuels and cement production between 2010 and 2012 occurred in China. Yet estimates of Chinese emissions remain subject to large uncertainty; inventories of China's total fossil fuel carbon emissions in 2008 differ by 0.3 gigatonnes of carbon, or 15 per cent. The primary sources of this uncertainty are conflicting estimates of energy consumption and emission factors, the latter being uncertain because of very few actual measurements representative of the mix of Chinese fuels. Here we re-evaluate China's carbon emissions using updated and harmonized energy consumption and clinker production data and two new and comprehensive sets of measured emission factors for Chinese coal. We find that total energy consumption in China was 10 per cent higher in 2000-2012 than the value reported by China's national statistics, that emission factors for Chinese coal are on average 40 per cent lower than the default values recommended by the Intergovernmental Panel on Climate Change, and that emissions from China's cement production are 45 per cent less than recent estimates. Altogether, our revised estimate of China's CO2 emissions from fossil fuel combustion and cement production is 2.49 gigatonnes of carbon (2 standard deviations = ±7.3 per cent) in 2013, which is 14 per cent lower than the emissions reported by other prominent inventories. Over the full period 2000 to 2013, our revised estimates are 2.9 gigatonnes of carbon less than previous estimates of China's cumulative carbon emissions. Our findings suggest that overestimation of China's emissions in 2000-2013 may be larger than China's estimated total forest sink in 1990-2007 (2.66 gigatonnes of carbon) or China's land carbon sink in 2000-2009 (2.6 gigatonnes of carbon).

  19. 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.

  20. Analysis of Trace Elements in South African Clinkers using Latent ...

    African Journals Online (AJOL)

    aDepartment of Process Engineering, University of Veszprém, P.O. Box 158, Veszprém ... of clinkers (and possibly of cements) can be used to identify the manufacturing factory. ... from the main raw materials (limestone, marl, clay) and not from.

  1. Influence of the joint incorporation of CaF2 and CaSO4 in the clinkerization process. Obtainment of new cements

    Directory of Open Access Journals (Sweden)

    Puertas, F.

    1995-09-01

    Full Text Available This article review the state of the art on the effect of the joint incorporation of fluorides and sulfates to the cement crudes. This incorporation may be carried out partially replacing the traditional crudes, thus obtaining a new cement produced with a considerable energy saving and with advantageous characteristics with regard to the traditional cement. The work presents a study of equilibrium diagrams of interest and mentions some industrial experiences developed by the researchers, authors of this article.En el presente artículo se revisa el estado del conocimiento sobre el efecto que ejerce la incorporación conjunta de fluoruros y sulfatos a crudos de cemento. Esta incorporación puede realizarse sustituyendo parcialmente los crudos tradicionales, obteniéndose así un nuevo cemento que se produce con un considerable ahorro energético y con prestaciones ventajosas respecto al tradicional. Se hace un estudio de los diagramas de equilibrio de interés y se citan algunas experiencias industriales desarrolladas por los investigadores autores del artículo.

  2. Characterization of cement minerals, cements and their reaction products at the atomic and nano scale

    DEFF Research Database (Denmark)

    Skibsted, Jørgen; Hall, Christopher

    2008-01-01

    Recent advances and highlights in characterization methods are reviewed for cement minerals, cements and their reaction products. The emphasis is on X-ray and neutron diffraction, and on nuclear magnetic resonance methods, although X-ray absorption and Raman spectroscopies are discussed briefly...

  3. Leaching of metals from cement under simulated environmental conditions.

    Science.gov (United States)

    Lu, Huixia; Wei, Fang; Tang, Jingchun; Giesy, John P

    2016-03-15

    Leaching of metals from cement under various environmental conditions was measured to evaluate their environmental safety. A cement product containing clinker, which was produced from cement kiln co-processing of hazardous wastes, was solidified and leaching of metals was characterized using the 8-period test. Concentrations and speciation of metals in cements were determined. Effects of ambient environment and particle size on leachability of metals and mineralogical phases of cement mortars were evaluated by use of XRD and SEM. Results indicated that metals in cements were leachable in various media in descending order of: sea water, groundwater and acid rain. Cr, Ni, As, Co and V were leached by simulated sea water, while Cu, Cd, Pb, Zn, Mn, Sb and Tl were not leached in simulated sea water, groundwater or acid rain. When exposed to simulated acid rain or groundwater, amounts of Cr, Ni, As and V leached was inversely proportional to particle size of cement mortar. According to the one-dimensional diffusion equation, Cr was most leachable and the cumulative leached mass was predicted to be 9.6 mg kg(-1) after 20 years. Results of this study are useful in predicting releases of metals from cement products containing ash and clinkers cement kiln co-processing of hazardous wastes, so that they can be safely applied in the environment.

  4. MIX DESIGN FOR OIL-PALM-BOILER CLINKER (OPBC) CONCRETE

    African Journals Online (AJOL)

    DEPT OF AGRICULTURAL ENGINEERING

    Keywords: Oil-Palm-Boiler Clinker (OPBC), Solid Waste, Mix Design, Lightweight Concrete, ... pality. These solid wastes and by-products, ... alternative to the conventional concrete materi- ... to produce steam to generate electricity for the.

  5. Evaluation of a lime-mediated sewage sludge stabilisation process. Product characterisation and technological validation for its use in the cement industry.

    Science.gov (United States)

    Rodríguez, N Husillos; Granados, R J; Blanco-Varela, M T; Cortina, J L; Martínez-Ramírez, S; Marsal, M; Guillem, M; Puig, J; Fos, C; Larrotcha, E; Flores, J

    2012-03-01

    This paper describes an industrial process for stabilising sewage sludge (SS) with lime and evaluates the viability of the stabilised product, denominated Neutral, as a raw material for the cement industry. Lime not only stabilised the sludge, raised the temperature of the mix to 80-100°C, furthering water evaporation, portlandite formation and the partial oxidation of the organic matter present in the sludge. Process mass and energy balances were determined. Neutral, a white powder consisting of portlandite (49.8%), calcite (16.6%), inorganic oxides (13.4%) and organic matter and moisture (20.2%), proved to be technologically apt for inclusion as a component in cement raw mixes. In this study, it was used instead of limestone in raw mixes clinkerised at 1400, 1450 and 1500°C. These raw meals exhibited greater reactivity at high temperatures than the limestone product and their calcination at 1500°C yielded clinker containing over 75% calcium silicates, the key phases in Portland clinker. Finally, the two types of raw meal (Neutral and limestone) were observed to exhibit similar mineralogy and crystal size and distribution.

  6. Estudio comparativo de clinkers producidos con diferentes reemplazos de combustibles residuales

    Directory of Open Access Journals (Sweden)

    Trezza Mónica Adriana

    2003-01-01

    Full Text Available In the last decades the cement industry has used, as a partial substitute for traditional fuel, different industrial wastes in order to profit their residuals energy. In the present work the physicochemical characteristics of clinker, obtained using trade marked alternative fuel for clinker kiln, were evaluated. X-ray diffraction (XRD, Blaine specific surface, pyrometric cone equivalent (PCE, differential thermal analysis-thermal gravimetry simultaneous (DTA-TG, differential calorimetry, porosimetry and mechanical strength were used as the main evaluation techniques of the characteristic of clinker and their behaviors in the early hydration. The additions of the wastes, within the percentages and under the conditions of this test, does no significantly alter the clinker properties but generates a greater crystallinity of the principal clinker phases.

  7. ECOLOGICAL STATUS AND DEVELOPMENT DIRECTIONS OF CEMENT INDUSTRY IN CHINA%我国水泥工业“生态化”的研究现状和发展趋势

    Institute of Scientific and Technical Information of China (English)

    郭随华; 翁端; 陈益民

    2001-01-01

    Ecological status and development directions of cement industry in China are discussed in this paper. To improve the ecological situation of the cement industry, the structure of products and the structure of the cement industry should be optimized. These optimizations include improvement of some small-scale cement plants to decrease the whole pollution level of the cement industry. Furthermore, researches on high reactive clinker, high reactive fine admixture of concrete and low-calcium series cement should be emphasized, by which the ecological design of cement, to reduce consumption and pollution of cement production and to improve the utilization efficiency of waste in cement production, can be realized. To produce low-calcium cement such as HBC would be benefit to the ecological production of cement because the clinker can be burned in a relatively low temperature and can be prepared with many low quality raw materials. The cement made from high reactive clinker can u utilize more wastes than traditional cement of the same grade. The cement containing no clinker or only a small amount of clinker is a typical kind of ecological cement. In addition, many researches also showed that the cement production could also be applied to environment protection such as soil upgrading or the use of domestic wastes as fuels in clinker burning.%分析探讨了中国水泥工业“生态化”的研究现状及发展趋势。为提高我国水泥工业发展的生态化水平,必须调整我国水泥工业的产业结构和产品结构,将高性能水泥熟料、高活性细掺料及低钙水泥系列熟料作为今后的研究重点,提高水泥中工业废弃物的利用效率,进行水泥产品生态化设计,以实现水泥生产的低消耗和低污染。

  8. Production of cement requiring low energy expenditure. An industrial test

    Energy Technology Data Exchange (ETDEWEB)

    Gimenez, S.; Blanco, M.T.; Palomo, A.; Puertas, F. (Instituto de Ciencias de la Construccion, Madrid (Spain))

    1991-01-01

    A new method for making cement is proposed. It is based on the use of CaF{sub 2} and CaSO{sub 4} for partial replacement of the usual raw materials in cement manufacturing. This paper shows the feasibility of the proposed method on an industrial scale. A test carried out in a Spanish cement factory (1500 t yield of the new cement) has revealed that the mehtod can not only be adapted to the current technology but also requires a much lower energy expenditure. The final product is shown to have excellent properties in comparison with OPC. (orig.).

  9. Use of alumina spent catalyst and RFCC wastes from petroleum refinery to substitute bauxite in the preparation of Portland clinker.

    Science.gov (United States)

    Al-Dhamri, Hilal; Melghit, Khaled

    2010-07-15

    Bauxite was substituted with spent catalysts for clinker preparation. Three different clinkers were prepared: one with bauxite as a reference, one with spent alumina catalyst and another with reduced fluid cracking catalyst. Powder X-ray diffraction technique, thermal analysis and scanning electron microscope were used to characterize each clinker sample. Rietveld refinement shows that, in all clinkers prepared, alite was formed with hexagonal lattice and monoclinic belite has higher unit cell volume compared to the known beta-Ca(2)SiO(4). The physical and mechanical properties (specific area, setting time, heat of hydration, soundness and compressive strength) of the cement samples were studied. The results show that substitution of bauxite by spent catalysts gave close results in terms of chemical composition, physical and mechanical properties of the Portland clinker. Also it shows the spent catalysts do not affect the quality of the prepared cement. 2010 Elsevier B.V. All rights reserved.

  10. Use of alumina spent catalyst and RFCC wastes from petroleum refinery to substitute bauxite in the preparation of Portland clinker

    Energy Technology Data Exchange (ETDEWEB)

    Al-Dhamri, Hilal [Chemistry Department, College of Science, Sultan Qaboos University, P.O. Box 36, Al-Khodh 123 (Oman); Melghit, Khaled, E-mail: melghit@squ.edu.om [Chemistry Department, College of Science, Sultan Qaboos University, P.O. Box 36, Al-Khodh 123 (Oman)

    2010-07-15

    Bauxite was substituted with spent catalysts for clinker preparation. Three different clinkers were prepared: one with bauxite as a reference, one with spent alumina catalyst and another with reduced fluid cracking catalyst. Powder X-ray diffraction technique, thermal analysis and scanning electron microscope were used to characterize each clinker sample. Rietveld refinement shows that, in all clinkers prepared, alite was formed with hexagonal lattice and monoclinic belite has higher unit cell volume compared to the known {beta}-Ca{sub 2}SiO{sub 4}. The physical and mechanical properties (specific area, setting time, heat of hydration, soundness and compressive strength) of the cement samples were studied. The results show that substitution of bauxite by spent catalysts gave close results in terms of chemical composition, physical and mechanical properties of the Portland clinker. Also it shows the spent catalysts do not affect the quality of the prepared cement.

  11. Gasification of secondary fuels in a circulating fluidized bed for energetic use in cement production; Vergasung von Sekundaerbrennstoffen in der zirkulierenden Wirbelschicht zur energetischen Nutzung fuer die Zementherstellung

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht, J.; Gafron, B. [Lurgi Umwelt GmbH, Frankfurt am Main (Germany); Scur, P.; Wirthwein, R. [Ruedersdorfer Zement GmbH (Germany)

    1998-09-01

    Ruedersforf cement factory was commissioned a century ago as one of the first in Germany. After the plant was taken over by Readymix AG, a comprehensive sanitation concept was carried through. The plant has a production capacity of 8000 t/d of cement clinkers which are produced in a new kiln with a capacity of 6000 t/d and two modernized kilns each with a capacity of 1000 t/d. Reduction of energy consumption was the main goal of modernisation, with fuel gas generation in a circulating fluidized bed as a key element. The unit provides 40 % of the energy consumed by the clinker production process and is also used for selective ash production up to 25 t/h. The ash is used as a raw material for cement production. (orig./SR) [Deutsch] Bereits vor 100 Jahren wurde eine der ersten Zementfabriken in Deutschland am Standort Ruedersdorf in Betrieb genommen. Zum Erhalt der Wettbewerbsfaehigkeit wurde nach der Uebernahme des Werkes Ruedersdorf durch die Readymix AG ein umfangreiches Sanierungskonzept in die Wege geleitet. Bei einer Produktionskapazitaet von ca. 8 000 t Klinker pro Tag werden eine neue Ofenanlage mit einer Kapazitaet von 6 000 t/Tag sowie 2 sanierte kleine Anlagen zu je 1000 t/Tag betrieben. In der neuen Ofenanlage werden alle Moeglichkeiten genutzt, den Energiebedarf fuer die Klinkerproduktion zu senken. Eine wesentliche neue innovative Komponente ist dabei eine Brenngaserzeugung in einer Zirkulierenden Wirbelschicht, ueber die im folgenden berichtet werden soll. Die Anlage kann bis zu 40% des Energiebedarfes des Zementprozesses liefern. Weiterhin wird mit der ZWS eine gezielte Ascheproduktion, bis zu 25 t/h, betrieben. Diese Aschen sind Teil der Rohstoffrezeptur an der Rohmuehle. (orig./SR)

  12. Front line of cement technolgy and control. Part 5. ; Baking process and chemical reactions. Cement saisentan sono gijutsu to kanri 5. ; Shosei katei to kagaku hanno

    Energy Technology Data Exchange (ETDEWEB)

    Hirai, M. (Ube Industries, Ltd., Yamaguchi (Japan))

    1990-06-01

    The baking process in cement production means the process that the raw materials which were mixed and pulverized in the raw material preparation process are charged into a reaction furnace which is called kiln, and clinders (intermediate product of cement) are generated. It is the process which affects quality as well as production cost of cement more significantly than anything else. In this article, an outline of the above baking facilities, how the raw materials change and clinkers are generated therein, and how they are controlled are introduced. Clinkers are composed of such products as alite, belite, aluminate and ferrite, etc. which were generated after decomposition reactions of such raw materials as lime stone, clay, silica rock and iron oxide in the above kiln. The essential ponts of the process control which makes the generation reactions of clinker compounds efficiently are such two points as well balanced raw materials to be charged into the baking facilities and stable operation of such facilities. The quality of cement which is required as finished goods is achieved by the quality control at each intermediate process and the quality tests of cement. 5 refs., 10 figs., 2 tabs.

  13. Strength improvement of fibre cement product

    Directory of Open Access Journals (Sweden)

    Waranya Sonphuak

    2013-10-01

    Full Text Available This paper presents a methodology to improve the strength or the Modulus of Rupture (MOR of fibre cement. The Six Sigma approach with the DMAIC steps was applied to a case study company. This research started from defining problem, setting the project objective and the project scope. Next, the measurement system was analyzed and the process map was set up. The potential factors of the problem was then determined. Due to there were many factors that affect the MOR, the Cause and Effect Matrix and the Failure Mode and Effect Analysis technique were then used to reduce the number of factors to be studied further. Next, three process factors, which were the pulp slurry freeness, the film-layer thickness, and the pressure step, were optimized using the results from the Box-Behnken experimental design. Other 13 remaining factors were improved by creating or revising the standard work instructions and training the operators. After that, the statistical process control and the control plan were set up to control the production processes. After improvement, the process capability index (Ppk significantly increased from 0.26 to 1.35.

  14. Basalt waste added to Portland cement

    Directory of Open Access Journals (Sweden)

    Thiago Melanda Mendes

    2016-08-01

    Full Text Available Portland cement is widely used as a building material and more than 4.3 billion tons were produced in 2014, with increasing environmental impacts by this industry, mainly through CO2 emissions and consumption of non-removable raw materials. Several by-products have been used as raw materials or fuels to reduce environmental impacts. Basaltic waste collected by filters was employed as a mineral mixture to Portland cement and two fractions were tested. The compression strength of mortars was measured after 7 days and Scanning Electron Microscopy (SEM and Electron Diffraction Scattering (EDS were carried out on Portland cement paste with the basaltic residue. Gains in compression strength were observed for mixtures containing 2.5 wt.% of basaltic residue. Hydration products observed on surface of basaltic particles show the nucleation effect of mineral mixtures. Clinker substitution by mineral mixtures reduces CO2 emission per ton of Portland cement.

  15. Recycling of the product of thermal inertization of cement-asbestos for various industrial applications.

    Science.gov (United States)

    Gualtieri, Alessandro F; Giacobbe, Carlotta; Sardisco, Lorenza; Saraceno, Michele; Gualtieri, Magdalena Lassinantti; Lusvardi, Gigliola; Cavenati, Cinzia; Zanatto, Ivano

    2011-01-01

    Recycling of secondary raw materials is a priority of waste handling in the countries of the European community. A potentially important secondary raw material is the product of the thermal transformation of cement-asbestos, produced by prolonged annealing at 1200-1300 °C. The product is chemically comparable to a Mg-rich clinker. Previous work has assured the reliability of the transformation process. The current challenge is to find potential applications as secondary raw material. Recycling of thermally treated asbestos-containing material (named KRY·AS) in traditional ceramics has already been studied with successful results. The results presented here are the outcome of a long termed project started in 2005 and devoted to the recycling of this secondary raw materials in various industrial applications. KRY·AS can be added in medium-high percentages (10-40 wt%) to commercial mixtures for the production of clay bricks, rock-wool glasses for insulation as well as Ca-based frits and glass-ceramics for the production of ceramic tiles. The secondary raw material was also used for the synthesis of two ceramic pigments; a green uvarovite-based pigment [Ca(3)Cr(2)(SiO(4))(3)] and a pink malayaite-based pigment [Ca(Sn,Cr)SiO(5)]. The latter is especially interesting as a substitute for cadmium-based pigments. This work also shows that KRY·AS can replace standard fillers in polypropylene plastics without altering the properties of the final product. For each application, a description and relevant results are presented and discussed.

  16. Organic Additive Implantation onto Cement Hydration Products

    Institute of Scientific and Technical Information of China (English)

    ZHU Jipeng; LI Zongjin; YANG Ruochong; ZHANG Yamei

    2014-01-01

    In polymer modified cementitious materials, it is hard to set up a chemical connection between the added polymer and the cement moiety. In this study FS (functional silane) was adopted to form this connection as a bridge component which has the functional group forming bonds with polymer. To testify the connection between FS and cement moiety, Q2/Q1 ratio (Qx:intensity ratio) investigation was carried out by the means of quantitative solid state 29Si MAS NMR. The results show that the Q2/Q1 ratio has increased with the addition of FS which indicates that the silicon chain length has increased, and the quantity of silicon atoms at site of Q2, chain site, has enhanced, showing that the silicon atom of FS has connected to the silicon chain of cement moiety by the bond“-Si-O-Si-”formation.

  17. 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 ...

  18. Feasibility of disposing waste glyphosate neutralization liquor with cement rotary kiln

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Y.; Bao, Y.B.; Cai, X.L.; Chen, C.H. [College of Materials Science and Engineering, Nanjing Tech University, Nanjing 210009 (China); State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 210009 (China); Ye, X.C., E-mail: yexuchu@njtech.edu.cn [College of Materials Science and Engineering, Nanjing Tech University, Nanjing 210009 (China); State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 210009 (China)

    2014-08-15

    Highlights: • The waste neutralization liquor was injected directly into the kiln system. • No obvious effect on the quality of cement clinker. • The disposing method was a zero-discharge process. • The waste liquor can be used as an alternative fuel to reduce the coal consumption. - Abstract: The waste neutralization liquor generated during the glyphosate production using glycine-dimethylphosphit process is a severe pollution problem due to its high salinity and organic components. The cement rotary kiln was proposed as a zero discharge strategy of disposal. In this work, the waste liquor was calcinated and the mineralogical phases of residue were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD). The mineralogical phases and the strength of cement clinker were characterized to evaluate the influence to the products. The burnability of cement raw meal added with waste liquor and the calorific value of waste liquor were tested to evaluate the influence to the thermal state of the kiln system. The results showed that after the addition of this liquor, the differences of the main phases and the strength of cement clinker were negligible, the burnability of raw meal was improved; and the calorific value of this liquor was 6140 J/g, which made it could be considered as an alternative fuel during the actual production.

  19. Environmental CRIteria for CEMent based products, ECRICEM. Phase I. Ordinary Portland Cements. Phase II. Blended Cements. Executive Summary

    Energy Technology Data Exchange (ETDEWEB)

    Van der Sloot, H.A.; Van Zomeren, A. [ECN Biomass, Coal and Environmetal Research, Petten (Netherlands); Stenger, R. [Holcim Group Support Ltd, Holderbank (Switzerland); Schneider, M.; Spanka, G. [VDZ, Duesseldorf (Germany); Stoltenberg-Hansson, A. [NORCEM, HeidelbergCement Group, Brevik (Norway); Dath, P. [Holcim Belgium, Obourg (Belgium)

    2008-01-15

    The protection of the immediate environment of structural works is one of the essential requirements of the European Construction Products Directive (CPD). According to the CPD, construction products can only be put on the market, if the structural works built with them fulfil the relevant requirements for hygiene, and the protection of health and the environment. These essential requirements in the respective standards are specified at the national level by the individual member states. Cement and cementitious materials are considered to fulfil the fundamental requirements of the European Construction Products Directive and the corresponding national regulations. Therefore a technical regulation like the cement standard EN 197 in general does not cover separate requirements for determining compliance of cementitious materials with criteria on hygiene, health and environmental protection. Further regulations are laid down in cases where it appears necessary for constructive applications requiring a particular protection of water, soil and air.

  20. Long-term sampling of dioxin-like substances from a clinker kiln stack using alternative fuels.

    Science.gov (United States)

    Rivera-Austrui, J; Martinez, K; Marco-Almagro, L; Abalos, M; Abad, E

    2014-07-01

    The aim of this work is to characterize atmospheric emissions of polychlorinated dibenzo-p-dioxins (PCDDs)/polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) from a cement production plant where the existing clinker production line was completely replaced by a new state-of-the-art installation. The project started in April 2008 with the installation of a long-term sampling system in the stack of the clinker kiln that used petroleum coke as fuel; PCDD/PCDF and dl-PCB emissions were then evaluated for a two year period. To carry out the second part of the study, in 2010 the sampling system was moved to the new installation in which, apart from conventional fuel, recovered derived fuel (RDF) and WWTP sludge were used as alternative fuels. For both the old and new clinker kilns, PCDD/PCDF emission values were well below the limit established by the European Waste Incineration Directive 2000/76/CE (EWID) of 100 pg I-TEQ/Nm(3); values ranged from 0.43 to 2.02 and from 0.07 to 3.31 pg I-TEQ/Nm(3), respectively. dl-PCBs accounted for approximately 25% of the WHO-TEQ toxicity. These results prove that the installation is capable of reducing PCDD/PCDF and dl-PCB emissions when alternative fuels are integrated into the process. In the case of PCDDs/PCDFs, the major contributions to total TEQ were usually from 2,3,7,8-TCDD (owing to its relative abundance) and 2,3,4,7,8-PeCDF (due to its high I-TEF of 0.5); while for dl-PCBs, the major contribution was from PCB-126. The slight shift in the congener profile between the old and new installations was characterized and a regression model was proposed for dl-PCB emissions depending on the RDF flow rate in the clinker.

  1. Mineralogical composition and phase-to-phase relationships in natural hydraulic lime and/or natural cement - raw materials and burnt products revealed by scanning electron microscopy

    Science.gov (United States)

    Kozlovcev, Petr; Přikryl, Richard; Racek, Martin; Přikrylová, Jiřina

    2016-04-01

    In contrast to modern process of production of cement clinker, traditional burning of natural hydraulic lime below sintering temperature relied on the formation of new phases from ion migration between neighbouring mineral grains composing raw material. The importance of the mineralogical composition and spatial distribution of rock-forming minerals in impure limestones used as a raw material for natural hydraulic lime presents not well explored issue in the scientific literature. To fill this gap, the recent study focuses in detailed analysis of experimentally burnt impure limestones (mostly from Barrandian area, Bohemian Massif). The phase changes were documented by optical microscopy, X-ray diffraction, and scanning electron microscopy with an energy dispersive spectrometer (SEM-EDS) coupled with x-ray elemental mapping. The latest allowed for visualization of distribution of elements within raw materials and burnt products. SEM/EDS study brought valuable data on the presence of transitional and/or minor phases, which were poorly detectable by other methods.

  2. Chloride influence on the incorporation of Cr(2)O(3) and NiO in clinker: a laboratory evaluation.

    Science.gov (United States)

    Barros, A M; Tenório, J A S; Espinosa, D C R

    2002-07-22

    Co-incinerating wastes in cement rotary kilns may introduce elements not usually found in the raw material into the process or even increase the quantity of some minor elements. Chromium and nickel are present in some electroplating sludges. These wastes are hazardous and must be treated and disposed of in a controlled landfill. The objective of this work was to study the incorporation of chromium and nickel oxides when they were added to clinker raw meal. The clinker raw meal used in this study was prepared by mixing pure compounds in the ratio that made it possible to obtain the same phases of an industrial Portland clinker at the end of the heating process. Twelve samples were prepared by adding 0.05, 0.1, 0.3, 0.5, 0.8 and 1.0wt.% of Cr(2)O(3) and 0.05, 0.1, 0.3, 0.5, 0.8 and 1.0wt.% of NiO to the base charge. Also, four more samples were prepared with additions of 0.6% Cr(2)O(3) and 0.1% NaCl, 0.7% Cr(2)O(3) and 0.1% KCl, 0.8% NiO and 0.1% NaCl and 0.8% NiO and 0.1% KCl. In order to study the Cr and Ni incorporation, thermogravimetric (TG) tests were performed, as well as tests in an assembled experimental device. The products were characterized by X-ray fluorescence chemical analysis, microprobe analyses by energy disperse scanning (EDS) and leaching tests. The results showed that the chromium and nickel added were incorporated into the clinker, even when chlorides were present.

  3. Integrated Environmental Quality Assessments of Surface Water around Obajana Cement Production Area

    Directory of Open Access Journals (Sweden)

    E.G. Ameh

    2014-04-01

    Full Text Available Due to industrialization, there is enormous amount of heavy metals been released from anthropogenic sources into the environment. Heavy metals are considered as one of the main sources of environmental pollution since they have significant effect on the ecological quality and water in particular. These pollutants are hazardous to consumers of water that have significant quantity of these heavy metals. The population most exposed to cement polluted water includes workers in cement factories, families of workers living in Staff houses of factories like in Obajana and other neighborhood habitations. The Obajana cement factory consists of cement kilns/coolers with clinkers. The kilns are equipped with pre-heaters and Electro-Static Precipitators (ESP. The facility has raw mills, crushing operations, cement mills that are potential source of pollutants into the water bodies. Storage silos, conveyors, vehicular travel, and other unquantified fugitive source of water contamination exist in the factory. Monitoring the contamination of water with respect to heavy metals is of interest due to their influence on humans, animals and to some extent plants. A good approach to estimate how much of the water is impacted is by using the heavy metal pollution index and metal index for metal concentrations above the control points in water bodies around Obajana cement.

  4. Carbonate Looping for De-Carbonization of Cement Plants

    DEFF Research Database (Denmark)

    Pathi, Sharat Kumar; Andersen, Maria Friberg; Lin, Weigang

    2011-01-01

    Cement industry is one of the largest emitter of CO2 other than power generation plants, which includes the emissions from combustion of fuel and also from calcination of limestone for clinker production. In order to reduce CO2 emissions from the cement industry an effective an economically...... feasible technology is to be developed. The carbonate looping process is a promising technology, which is particularly suitable for the cement industry as limestone could be used for capture and release of CO2. Integration of carbonate looping process into cement pyroprocess has two advantages: 1...... integrated into cement pyro-process. The energy required for regeneration in the calciner increases with increase in average conversion of calcined limestone and energy that can be extracted from carbonator decreases with increasing average conversion. Further the influence of type of limestone...

  5. Design and optimisation of new formulations of Belite-Alite Calcium Sulfoaluminate (BACSA) eco-cements

    OpenAIRE

    Londono-Zuluaga, Diana; SANTACRUZ, ISABEL; Tobón, Jorge Iván; Aranda, Miguel A. G.; De la Torre, Angeles G.

    2015-01-01

    Belite Calcium SulfoAluminate (BCSA) eco-cements were developed as OPC substitutes since in their production release 22% less CO2 than OPC. BCSA eco-cements contain belite as main phase (>50 wt%) and ye'elimite as secondary main phase (~30 wt%). However, these materials develop low mechanical strengths at intermediate hydration ages (3, 7 and 28 days). A solution to this problem may involve the design and preparation of clinker/cement with the highest percentage of coexisting alite and ye'eli...

  6. Microwave processing of cement and concrete materials – towards an industrial reality?

    Energy Technology Data Exchange (ETDEWEB)

    Buttress, Adam, E-mail: adam.buttress@nottingham.ac.uk; Jones, Aled; Kingman, Sam

    2015-02-15

    Each year a substantial body of literature is published on the use of microwave to process cement and concrete materials. Yet to date, very few if any have lead the realisation of a commercial scale industrial system and is the context under which this review has been undertaken. The state-of the–art is evaluated for opportunities, and the key barriers to the development of new microwave-based processing techniques to enhance production, processing and recycling of cement and concrete materials. Applications reviewed include pyro-processing of cement clinker; accelerated curing, non-destructive testing and evaluation (NDT&E), and end-of-life processing including radionuclide decontamination.

  7. Prospection of Portland cement raw material: A case study in the Marmara region of Turkey

    Science.gov (United States)

    Özgüner, A. M.

    2014-09-01

    Representative sampling of the raw materials used to make Portland cement, correct calculations for the possible clinker mixtures, sufficient reserves of the raw materials and selection of the correct infrastructure for the location of a cement factory are essential to the protection of the great investment in the factory. The results of chemical analyses of pipe samples taken in the field at right angles to the strikes of favourable limestone, clay, shale, and marl outcrops were used in Kind's lime saturation formula for clinker calculations of the possible mixtures. The cement modulus values were calculated using the corresponding clinker oxide ratios and were confirmed to be within the standard intervals for positive cement raw material mixtures. The most promising raw material source, a double lithologic mixture of limestone and mudstone was found during the prospection in north of Bilecik Province, where rhyolitic tuff outcrops with pozzolanic properties also exist. Some marble quarries nearby have been inclined to dispose of their marble wastes for use in cement production to prevent polluting the environment with them. The nearby Gemlik fertiliser factory provides inexpensive waste gypsum that can be used as a cool cement mixing material. The limestone, mudstone and trass raw material reserves in this area were calculated to be sufficient for the factory's requirements for more than 100 years of operation as results of the detailed geological mapping. The regional infrastructure is most suitable for distribution and marketing of cement products. The cement factory described in this study has been producing cement for the last 3 years, after coring and testing of the raw material reserves.

  8. Novorossiysk agglomeration landscapes and cement production: geochemical impact assessment

    Science.gov (United States)

    Alekseenko, A. V.; Pashkevich, M. A.

    2016-09-01

    The article deals with assessing the environmental impact of marl mining and cement production in Novorossiysk city (Krasnodar krai, Russia). The existing methods of studying the environmental effects caused by the cement industry have been reviewed. Soil and aquatic vegetation sampling has been carried out and the gross concentration of metals in the samples has been defined. The research has been conducted in the certified and accredited laboratory using emission spectral analysis. The external control has been carried out via X-ray fluorescence analysis. Based on the collected data, main chemical pollutants in soil cover and water area near the cement plant have been identified. The contaminants released by urban enterprises and motor vehicle emissions, as well as fugitive dust from dumps and the cement factory, lead to multi-element lithogeochemical anomaly at geochemical barriers in soils. Accumulation of pollutants in soil depends on the type of land use and the area relief. The most contaminated aquatic landscapes have been identified in the inner bay. According to this information, the technical proposals can be prepared for environmental safety management in strongly polluted city areas, as well as for the reclamation design in the areas currently experiencing the negative impact of cement production.

  9. Energy Efficiency Improvement Opportunities for the Cement Industry

    Energy Technology Data Exchange (ETDEWEB)

    Price, Lynn; Worrell, Ernst; Galitsky, Christina; Price, Lynn

    2008-01-31

    This report provides information on the energy savings, costs, and carbon dioxide emissions reductions associated with implementation of a number of technologies and measures applicable to the cement industry. The technologies and measures include both state-of-the-art measures that are currently in use in cement enterprises worldwide as well as advanced measures that are either only in limited use or are near commercialization. This report focuses mainly on retrofit measures using commercially available technologies, but many of these technologies are applicable for new plants as well. Where possible, for each technology or measure, costs and energy savings per tonne of cement produced are estimated and then carbon dioxide emissions reductions are calculated based on the fuels used at the process step to which the technology or measure is applied. The analysis of cement kiln energy-efficiency opportunities is divided into technologies and measures that are applicable to the different stages of production and various kiln types used in China: raw materials (and fuel) preparation; clinker making (applicable to all kilns, rotary kilns only, vertical shaft kilns only); and finish grinding; as well as plant wide measures and product and feedstock changes that will reduce energy consumption for clinker making. Table 1 lists all measures in this report by process to which they apply, including plant wide measures and product or feedstock changes. Tables 2 through 8 provide the following information for each technology: fuel and electricity savings per tonne of cement; annual operating and capital costs per tonne of cement or estimated payback period; and, carbon dioxide emissions reductions for each measure applied to the production of cement. This information was originally collected for a report on the U.S. cement industry (Worrell and Galitsky, 2004) and a report on opportunities for China's cement kilns (Price and Galitsky, in press). The information provided in

  10. 基于LCA方法的水泥企业清洁生产审核%Cleaner production audit for a cement enterprise based on LCA

    Institute of Scientific and Technical Information of China (English)

    朴文华; 陈郁; 张树深; 徐小宁

    2012-01-01

    Cement production has received increasing attention due to its high consumption of energy and resource.Life cycle assessment(LCA) is an effective tool for cleaner production audits.We constructed LCA model to quantify emissions and resource consumption in each phase of the cement production process for a cement plant in Dalian.We evaluated the environmental impact caused by materials mining,transportation,raw material preparation,clinker calcination and finish grinding and mixing,which are general processes that are involved in cement materials production and transportation.Cradle-to-grave analysis was performed using the GaBi4 software with CML 2001 Dec 07 by which global warming,human toxicity and acidification potential influence was analyzed and compared.Result shows that during the whole lifetime of cement production,clinker calcination could cause the most important impact to the environment in terms of carbon dioxide discharging and smog generation,etc.Furthermore,clinker calcination is also ranked the first place in energy consumption.According to the result of LCA analysis,the focus of cleaner production audit and the cleaner production plan were put forward.In addition,we selected the plan with the most significant waste heat generation,and compared the environmental assessment before and after the implementation of this plan,to quantitatively analyze the cleaner production plan.%水泥行业是典型的高能耗、高污染的工业,其快速发展带来了严重的资源、能源、环境等问题.因此,本文选择生命周期评价方法(LCA)作为清洁生产审核工具,对大连某水泥企业进行了清洁生产审核.本文在调研水泥工艺及现状的基础上,运用生命周期评价方法对水泥生产过程中原料开采、运输、生料制备、煤粉制备、熟料煅烧及水泥粉磨阶段进行清单分析与建模.采用了生命周期评价软件Gabi4进行清单计算与分析,评价模型为CML2001Dec07特征化模

  11. Environmental Assessment of Different Cement Manufacturing ...

    Science.gov (United States)

    Due to its high environmental impact and energy intensive production, the cement industry needs to adopt more energy efficient technologies to reduce its demand for fossil fuels and impact on the environment. Bearing in mind that cement is the most widely used material for housing and modern infrastructure, the aim of this paper is to analyse the Emergy and Ecological Footprint of different cement manufacturing processes for a particular cement plant. There are several mitigation measures that can be incorporated in the cement manufacturing process to reduce the demand for fossil fuels and consequently reduce the CO2 emissions. The mitigation measures considered in this paper were the use of alternative fuels and a more energy efficient kiln process. In order to estimate the sustainability effect of the aforementioned measures, Emergy and Ecological Footprint were calculated for four different scenarios. The results show that Emergy, due to the high input mass of raw material needed for clinker production, stays at about the same level. However, for the Ecological Footprint, the results show that by combining the use of alternative fuels together with a more energy efficient kiln process, the environmental impact of the cement manufacturing process can be lowered. The research paper presents an analysis of the sustainability of cement production , a major contributor to carbon emissions, with respect to using alternative fuels and a more efficient kiln. It show

  12. Prediction of potential compressive strength of Portland clinker from its mineralogy

    DEFF Research Database (Denmark)

    Svinning, K.; Høskuldsson, Agnar; Justnes, H.

    2010-01-01

    Based on a statistical model first applied for prediction of compressive strength up to 28 d from the microstructure of Portland cement, potential compressive strength of clinker has been predicted from its mineralogy. The prediction model was evaluated by partial least squares regression. The mi...

  13. The influence of phosphorous pentoxide on the phase composition and formation of Portland clinker

    Energy Technology Data Exchange (ETDEWEB)

    Stanek, T., E-mail: stanek@vustah.cz [Research Institute of Building Materials, Hnevkovskeho 65, 617 00 Brno (Czech Republic); Sulovsky, P., E-mail: sulovsky@sci.muni.cz [Department of Geological Sciences, Faculty of Science, Masaryk University, Kotlarska 2, 611 37 Brno (Czech Republic)

    2009-07-15

    The influence of phosphorous pentoxide (P{sub 2}O{sub 5}) on the phase composition and formation of Portland clinker was studied in laboratory conditions. Phosphorous pentoxide in the form of calcium phosphate was added to common cement-making raw meal in graded quantities up to 5 wt.%. The raw meal properties were studied by thermal analysis. The development of clinker formation by burning for periods ranging from 20 s to 30 min in a special semi-automatic oven with a manipulator was followed using light optical microscopy. The phase composition of clinkers burnt to equilibrium was quantified by the optical point counting method. The entry of P{sub 2}O{sub 5} into clinker minerals was determined by electron microprobe analyses. The laboratory tests show that at 0.7 wt.% of P{sub 2}O{sub 5} in the clinker the alite (Ca{sub 3}SiO{sub 5}) content decreases and belite (Ca{sub 2}SiO{sub 4}) content increases. At a P{sub 2}O{sub 5} content of 4.5 wt.% alite formation was totally blocked and the resulting clinker contained free lime in equilibrium with belite.

  14. Raw mix designing, clinkerization and manufacturing of high-strength Portland cement from the limestone and clay of Darukhula Nizampur, Nowshera District, North-West Frontier Province (N.W.F.P.), Pakistan

    Institute of Scientific and Technical Information of China (English)

    Noor-ul-Amin; Tahir Shah; Khurshid Ali

    2009-01-01

    This paper covers the detailed version of the potential raw material deposits at Darukhula and the adjacent areas of Nizampur, the manufacturing of high-strength Portland cement samples from the same material and comparison of the physical and chemical parameters for resulting cement with British and Pakistan standard specifications, which include compressive strength, setting time, consistency, lechatelier expansion, Blaine and insoluble residue. It was found that the raw material available in the study area meets the standard specifications and the area is feasible for the cement plant installation. The area can provide raw material which is quite sufficient for the running of a cement plant.

  15. 用废铝渣制备膨胀和自应力硫铝酸盐水泥的研究%Preparation of Expansive and Self-stressing Sulphoaluminate Cement Using Bauxite Waste

    Institute of Scientific and Technical Information of China (English)

    冯庆革; 邱树恒; 杨义; 陈明源; 程伟

    2007-01-01

    In this study, bauxite waste was used instead of bauxite to produce sulphoaluminate clinker. With orthogonal design the technical parameters, for production of sulphoaluminate clinker were studied. Expansive and self-stressing sulphoaluminate cements were prepared using the clinkers produced by varying the added amount of gypsum. The results show that: (1) Using bauxite waste to make sulphoaluminate cement is feasible;(2) The optimum condition for the production of clinker are N= 3.9, P= 2.8, Cm= 0.99 and Tb =1350 ℃;(3) The physical properties of the prepared cement conform to the standard of self-stressing and expansive cement.%通过正交试验设计,研究了用废铝渣替代铝矾土制备硫铝酸盐水泥熟料,调整石膏掺量制备膨胀和自应力水泥.研究结果表明:①用废铝渣替代铝矾土制备硫铝酸盐水泥熟料是可行的;②最佳熟料煅烧条件为N = 3.9, P = 2.8, Cm = 0.99 和煅烧温度 Tb =1350 ℃;③制备的水泥物理性能符合膨胀和自应力水泥国家标准.

  16. Static Model of Cement Rotary Kiln

    Directory of Open Access Journals (Sweden)

    Omar D. Hernández-Arboleda

    2013-11-01

    Full Text Available In this paper, a static model of cement rotary kilns is proposed. The system model is obtained through polynomial series. The proposed model is contrasted with data of a real plant, where optimal results are obtained. Expected results are measured with respect to the clinker production and the combustible consumption is measured in relation with the consumption calorific. The expected result of the approach is the increase of the profitability of the factory through the decrease of the consumption of the combustible.

  17. CO2 Capture for Cement Technology

    DEFF Research Database (Denmark)

    Pathi, Sharat Kumar

    performed recently has focused on CO2capture from fossil fuel-based power plants. Inherently,this process is especially suitablefor cement plants, as CaO used for CO2capture is also a majoringredient for clinker production. Thus, a detailed investigation was carried outto study the applicationof......% of the inlet CO2 was captured by highly deactivated limestone, which had a maximum CO2 capture capacity of 11.5%, with an inlet Ca/C ratio of 13. So, the performance of the carbonator can be defined by the inlet Ca/C ratio, which can be estimated if the maximum capture capacity of limestone is known...

  18. Valorisation of electric arc furnace steel slag as raw material for low energy belite cements.

    Science.gov (United States)

    Iacobescu, R I; Koumpouri, D; Pontikes, Y; Saban, R; Angelopoulos, G N

    2011-11-30

    In this paper, the valorisation of electric arc furnace steel slag (EAFS) in the production of low energy belite cements is studied. Three types of clinkers were prepared with 0 wt.% (BC), 5 wt.% (BC5) and 10 wt.% (BC10) EAFS, respectively. The design of the raw mixes was based on the compositional indices lime saturation factor (LSF), alumina ratio (AR) and silica ratio (SR). The clinkering temperature was studied for the range 1280-1400°C; firing was performed at 1380°C based on the results regarding free lime and the evolution of microstructure. In order to activate the belite, clinkers were cooled fast by blown air and concurrent crushing. The results demonstrate that the microstructure of the produced clinkers is dominated by belite and alite crystals, with tricalcium aluminate and tetracalcium-alumino-ferrite present as micro-crystalline interstitial phases. The prepared cements presented low early strength development as expected for belite-rich compositions; however the 28-day results were 47.5 MPa, 46.6 MPa and 42.8 MPa for BC, BC5 and BC10, respectively. These values are comparable with OPC CEMI 32.5 N (32.5-52.5 MPa) according to EN 197-1. A fast setting behaviour was also observed, particularly in the case of BC10, whereas soundness did not exceed 1mm.

  19. Cement Conundrum

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    China aims to streamline the crowded cement industry Policymakers are looking to build a concrete wall around the cement-making industry as they seek to solidify the fluid cement market and cut excessive production.

  20. 水泥生产中含SiO2粘土质原料的研究进展%Research Progress of the Utilization of Raw Materials Containing SiO2 in the Production of Clinker

    Institute of Scientific and Technical Information of China (English)

    秦守婉; 王惠芬; 吴明慧

    2013-01-01

    In the production of clinker, a large of clay was used as raw material. In order to reduce the consumption of clay, we should choose minerals, slag or tailings as raw material with SiO2 and Al2O3. The burnability of raw material, the rate of mineral formation, microstructure and hydration activity of clinker was influenced by the structure status of SiO2 in the raw meal. Some materials with SiO2 are introduced and different structure status and activation method of SiO2 are reviewed in this paper.%在水泥熟料的生产过程中,不可再生的粘土资源被大量消耗,要减少粘土的消耗量,可从岩矿、废渣、尾矿等几方面选择完全或部分替代物。不同原料矿物中所含SiO2的结构状态会影响生料反应能力、矿物形成的速度和完善程度、熟料结构和水化活性等。本文对不同原料矿物中SiO2的结构状态和性能以及改变其活性的方法进行了综述。

  1. The behavior of biogenic silica-rich rocks and volcanic tuffs as pozzolanic additives in cement

    Science.gov (United States)

    Fragoulis, Dimitris; Stamatakis, Michael; Anastasatou, Marianthi

    2015-04-01

    Cements currently produced, include a variety of pozzolanic materials, aiming for lower clinker addition and utilization of vast deposits of certain raw materials and/or mining wastes and byproducts. The major naturally occurring pozzolanic materials include glassy tuffs, zeolitic tuffs, diatomites and volcanic lavas rich in glassy phase, such as perlites. Therefore, based on the available raw materials in different locations, the cement composition might vary according to the accessibility of efficient pozzolanic materials. In the present investigation, the behavior of pozzolanic cements produced with representative samples of the aforementioned materials was studied, following the characterization of the implemented pozzolanas with respect to their chemical and mineralogical characteristics. Laboratory cements were produced by co-grinding 75% clinker, 5% gypsum and 20% pozzolana, for the same period of time (45 min). Regarding pozzolanic materials, four different types of pozzolanas were utilized namely, diatomite, perlite, zeolite tuff and glassy tuff. More specifically, two diatomite samples originated from Australia and Greece, with high and low reactive silica content respectively, two perlite samples originated from Turkey and from Milos Island, Greece, with different reactive silica contents, a zeolite tuff sample originated from Turkey and a glassy tuff sample originated from Milos Island, Greece. The above pozzolana samples, which were ground in the laboratory ball mill for cement production performed differently during grinding and that was reflected upon the specific surface area (cm2/gr) values. The perlites and the glassy tuff were the hardest to grind, whereas, the zeolite tuff and the Australian diatomite were the easiest ones. However, the exceedingly high specific surface area of the Australian diatomite renders cement difficult to transport and tricky to use for concrete manufacturing, due to the high water demand of the cement mixture. Regarding

  2. Characteristics of mercury cycling in the cement production process.

    Science.gov (United States)

    Wang, Fengyang; Wang, Shuxiao; Zhang, Lei; Yang, Hai; Wu, Qingru; Hao, Jiming

    2016-01-25

    The mercury cycling caused by dust shuttling significantly increases the atmospheric emissions from cement production. A comprehensive understanding of this mercury cycling can promote the development of mercury emission control technologies. In this study, the characteristics of mercury cycling in the cement production process were first investigated. Furthermore, the mercury enrichment and effects of dust treatment were evaluated based on the field tests conducted in two Chinese cement plants. The mercury cycling between the kiln system and the raw mill system was the most important aspect and contributed 57-73% to the total amount of mercury emitted from the kiln system. Mercury emitted from the kiln system with flue gas was enriched as high as 3.4-8.8 times in the two tested plants compared to the amount of mercury in the raw materials and coal due to mercury cycling. The mercury enrichment can be significantly affected by the proportion of mercury cycled back to the kiln system. The effects of dust treatment were evaluated, and dust treatment can efficiently reduce approximately 31-70% of atmospheric mercury emissions in the two plants. The reduction proportion approximately linearly decreased with the proportion of mercury removed from the collected dust.

  3. Carbon dioxide capture from a cement manufacturing process

    Science.gov (United States)

    Blount, Gerald C.; Falta, Ronald W.; Siddall, Alvin A.

    2011-07-12

    A process of manufacturing cement clinker is provided in which a clean supply of CO.sub.2 gas may be captured. The process also involves using an open loop conversion of CaO/MgO from a calciner to capture CO.sub.2 from combustion flue gases thereby forming CaCO.sub.3/CaMg(CO.sub.3).sub.2. The CaCO.sub.3/CaMg(CO.sub.3).sub.2 is then returned to the calciner where CO.sub.2 gas is evolved. The evolved CO.sub.2 gas, along with other evolved CO.sub.2 gases from the calciner are removed from the calciner. The reactants (CaO/MgO) are feed to a high temperature calciner for control of the clinker production composition.

  4. Development of Advanced Cement-Based Building Products

    Institute of Scientific and Technical Information of China (English)

    Zongjin LI; Bin MU; Stanley N.C.CHIU

    2000-01-01

    @@ In this study, short fiber-reinforced cement-based building products of sheets, pipes and honeycomb panels incorporating various mineral admixtures such as slag, silica fume, and metakaolin have been developed by the extrusion technique. The experimental works have shown that these products do have very good mechanical properties. Since the key point for a successful extrusion is the properly designed rheology which controls both internal and external flow properties of ext rudate, a nonlinear viscoelastic model was applied to investigate the rheology behavior of a movable fresh cementitious composite in a single screw extruder channel. The theoretical analysis is used to guide the practical manufacturing.

  5. 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.

  6. Use of MRF residue as alternative fuel in cement production.

    Science.gov (United States)

    Fyffe, John R; Breckel, Alex C; Townsend, Aaron K; Webber, Michael E

    2016-01-01

    Single-stream recycling has helped divert millions of metric tons of waste from landfills in the U.S., where recycling rates for municipal solid waste are currently over 30%. However, material recovery facilities (MRFs) that sort the municipal recycled streams do not recover 100% of the incoming material. Consequently, they landfill between 5% and 15% of total processed material as residue. This residue is primarily composed of high-energy-content non-recycled plastics and fiber. One possible end-of-life solution for these energy-dense materials is to process the residue into Solid Recovered Fuel (SRF) that can be used as an alternative energy resource capable of replacing or supplementing fuel resources such as coal, natural gas, petroleum coke, or biomass in many industrial and power production processes. This report addresses the energetic and environmental benefits and trade-offs of converting non-recycled post-consumer plastics and fiber derived from MRF residue streams into SRF for use in a cement kiln. An experimental test burn of 118 Mg of SRF in the precalciner portion of the cement kiln was conducted. The SRF was a blend of 60% MRF residue and 40% post-industrial waste products producing an estimated 60% plastic and 40% fibrous material mixture. The SRF was fed into the kiln at 0.9 Mg/h for 24h and then 1.8 Mg/h for the following 48 h. The emissions data recorded in the experimental test burn were used to perform the life-cycle analysis portion of this study. The analysis included the following steps: transportation, landfill, processing and fuel combustion at the cement kiln. The energy use and emissions at each step is tracked for the two cases: (1) The Reference Case, where MRF residue is disposed of in a landfill and the cement kiln uses coal as its fuel source, and (2) The SRF Case, in which MRF residue is processed into SRF and used to offset some portion of coal use at the cement kiln. The experimental test burn and accompanying analysis indicate

  7. SODIUM CITRATE INFLUENCE ON FORMATION OF CEMENT STONE IN THE ALUMINOUS BINDER

    Directory of Open Access Journals (Sweden)

    S. N. Leonovich

    2016-01-01

    Full Text Available The paper deals with the effect of sodium citrate on the formation of a cement stone in the aluminous binder. Formation of cement stone framework in cement hydraulic binder is accompanied with complicated physical and chemical processes of interphase interactions and dispersion, these processes are predicated on qualitative and quantitative composition of the cement mortar, continuous changes in its properties from preparation stage till curing. Addition of sodium citrate to tempering water enhances hydration of both Portland cement and calcium aluminate cement. Process pertaining to an increase of cement hydration rate is considered as a consequence of destruction in surface formations and exclusion of damping effect in respect of hydration rate and hydrolysis of products resulted from interaction of clinker material with tempering. It has been established that sodium citrate makes it possible to control processes of hydration, hydrolysis, binding and curing for cement mass. High degree of hydration of aluminous cement in the presence of sodium citrate provides fast binding and curing of binder, low porosity and rather high compression breaking strength of cement stone for all curing stages. An increase in concentration of sodium citrate in cement mixture up to 10 % of the cement mass exerts an influence not only on the process of cement mortar liquefaction, reduction of time for cement mass setting and hardening but also increases compression strength of cement stone. An analysis of the structure for cleavage surface of cement stone gives ground to declare that the addition of sodium citrate provides cement stone sealing and reduces its water absorption.

  8. Preparation of calcium sulphoaluminate cement using fertiliser plant wastes.

    Science.gov (United States)

    Singh, Maneesh; Kapur, P C; Pradip

    2008-08-30

    Phosphochalks from fertiliser plants contain significant amount of calcium sulphate along with P(2)O(5) and fluorine. The presence of these impurities makes them unsuitable for most applications and, hence its availability in millions of tons. We demonstrate that it is possible to prepare calcium sulphoaluminate-aluminoferrite based special cements having strength values comparable to ordinary Portland cement (OPC) using these waste chalks. Such cements are insensitive to the presence of impurities in the raw mixture, clinker at low temperatures (1,230 degrees C) and the clinkers produced are soft and friable. An empirical technique has been developed to predict the phase composition of the clinkers given the chemical composition of the starting raw mixture. The proposed low temperature clinkering route appears to be a promising method for converting waste phosphochalks into construction grade cements.

  9. Preparation of the saving-energy sulphoaluminate cement using MSWI fly ash.

    Science.gov (United States)

    Shi, Hui-sheng; Deng, Kai; Yuan, Feng; Wu, Kai

    2009-09-30

    MSWI fly ash was used as a major cement raw material in sintering sulphoaluminate cement clinker successfully in the laboratory. Sintering system, mechanical performance, hydration process and microstructure of the clinker was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray fluorescence spectrometry (XRF), etc. The result shows that the clinker can be sintered properly under the temperature of 1200-1300 degrees C and sintered time of 120 min. Cl(-) content in the clinker made with MSWI fly ash is about 1.08%. However most Cl(-) cannot leach out in water solution from the hardened cement paste during curing age between 1d and 28d because of the Cl(-) being combined in clinker minerals and its hydrates. The compressive strength of the sulphoaluminate cement was high in early age while that developed smoothly in later age.

  10. Preparation of the saving-energy sulphoaluminate cement using MSWI fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Shi Huisheng, E-mail: shs@tongji.edu.cn [Key Laboratory of Advanced Civil Engineering Materials of Education Ministry, Tongji University, 1239 Siping Road, Shanghai 200092 (China); Deng Kai; Yuan Feng; Wu Kai [Key Laboratory of Advanced Civil Engineering Materials of Education Ministry, Tongji University, 1239 Siping Road, Shanghai 200092 (China)

    2009-09-30

    MSWI fly ash was used as a major cement raw material in sintering sulphoaluminate cement clinker successfully in the laboratory. Sintering system, mechanical performance, hydration process and microstructure of the clinker was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray fluorescence spectrometry (XRF), etc. The result shows that the clinker can be sintered properly under the temperature of 1200-1300 deg. C and sintered time of 120 min. Cl{sup -} content in the clinker made with MSWI fly ash is about 1.08%. However most Cl{sup -} cannot leach out in water solution from the hardened cement paste during curing age between 1 d and 28 d because of the Cl{sup -} being combined in clinker minerals and its hydrates. The compressive strength of the sulphoaluminate cement was high in early age while that developed smoothly in later age.

  11. The transformation sequence of cement-asbestos slates up to 1200 deg. C and safe recycling of the reaction product in stoneware tile mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Gualtieri, A.F. [Dipartimento di Scienze della Terra, Universita di Modena e R.E., Via S. Eufemia 19, I-41100 Modena (Italy)], E-mail: alex@unimore.it; Cavenati, C.; Zanatto, I.; Meloni, M. [ZETADI S.r.l., Via dell' Artigianato 10, I-21010 Ferno (Italy); Elmi, G. [GE.PR.IN. S.r.l., Via Vaccari 48, I-41100 Modena (Italy); Gualtieri, M. Lassinantti [Dipartimento di Fisica, Universita di Modena e R.E., Via Campi 213/a, I-41100 Modena (Italy)

    2008-04-01

    minerals in this temperature-induced process. The product of transformation of cement-asbestos (CATP) has a phase composition similar to that of a natural or a low temperature clinker with the exception of having a larger content of aluminium, iron and magnesium. This product can be safely recycled for the production of stoneware tile mixtures. The addition of 3-5 mass% of CATP does not bear significant variations to the standard parameters of white porcelain tile mixtures.

  12. The transformation sequence of cement-asbestos slates up to 1200 degrees C and safe recycling of the reaction product in stoneware tile mixtures.

    Science.gov (United States)

    Gualtieri, A F; Cavenati, C; Zanatto, I; Meloni, M; Elmi, G; Gualtieri, M Lassinantti

    2008-04-01

    minerals in this temperature-induced process. The product of transformation of cement-asbestos (CATP) has a phase composition similar to that of a natural or a low temperature clinker with the exception of having a larger content of aluminium, iron and magnesium. This product can be safely recycled for the production of stoneware tile mixtures. The addition of 3-5 mass% of CATP does not bear significant variations to the standard parameters of white porcelain tile mixtures.

  13. Modeling of Pulverized Coal Combustion in Cement Rotary Kiln

    OpenAIRE

    2006-01-01

    In this paper, based on analysis of the chemical and physical processes of clinker formation, a heat flux function was introduced to take account of the thermal effect of clinker formation. Combining the models of gas-solid flow, heat and mass transfer, and pulverized coal combustion, a set of mathematical models for a full-scale cement rotary kiln were established. In terms of commercial CFD code (FLUENT), the distributions of gas velocity, gas temperature, and gas components in a cement rot...

  14. Cement industry control system based on multi agent

    Institute of Scientific and Technical Information of China (English)

    王海东; 邱冠周; 黄圣生

    2004-01-01

    Cement production is characterized by its great capacity, long-time delay, multi variables, difficult measurement and muhi disturbances. According to the distributed intelligent control strategy based on the multi agent, the multi agent control system of cement production is built, which includes integrated optimal control and diagnosis control. The distributed and multiple level structure of multi agent system for the cement control is studied. The optimal agent is in the distributed state, which aims at the partial process of the cement production, and forms the optimal layer. The diagnosis agent located on the diagnosis layer is the diagnosis unit which aims at the whole process of the cement production, and the central management unit of the system. The system cooperation is realized by the communication among optimal agents and diagnosis agent. The architecture of the optimal agent and the diagnosis agent are designed. The detailed functions of the optimal agent and the diagnosis agent are analyzed.At last the realization methods of the agents are given, and the application of the multi agent control system is presented. The multi agent system has been successfully applied to the off-line control of one cement plant with capacity of 5 000 t/d. The results show that the average yield of the clinker increases 9.3% and the coal consumption decreases 7.5 kg/t.

  15. Influence of ferrite phase in alite-calcium sulfoaluminate cements

    Science.gov (United States)

    Duvallet, Tristana Yvonne Francoise

    Since the energy crisis in 1970's, research on low energy cements with low CO2- emissions has been increasing. Numerous solutions have been investigated, and the goal of this original research is to create a viable hybrid cement with the components of both Ordinary Portland cement (OPC) and calcium sulfoaluminate cement (CSAC), by forming a material that contains both alite and calcium sulfoaluminate clinker phases. Furthermore, this research focuses on keeping the cost of this material reasonable by reducing aluminum requirements through its substitution with iron. The aim of this work would produce a cement that can use large amounts of red mud, which is a plentiful waste material, in place of bauxite known as an expensive raw material. Modified Bogue equations were established and tested to formulate this novel cement with different amounts of ferrite, from 5% to 45% by weight. This was followed by the production of cement from reagent chemicals, and from industrial by-products as feedstocks (fly ash, red mud and slag). Hydration processes, as well as the mechanical properties, of these clinker compositions were studied, along with the addition of gypsum and the impact of a ferric iron complexing additive triisopropanolamine (TIPA). To summarize this research, the influence of the addition of 5-45% by weight of ferrite phase, was examined with the goal of introducing as much red mud as possible in the process without negatively attenuate the cement properties. Based on this PhD dissertation, the production of high-iron alite-calcium sulfoaluminateferrite cements was proven possible from the two sources of raw materials. The hydration processes and the mechanical properties seemed negatively affected by the addition of ferrite, as this phase was not hydrated entirely, even after 6 months of curing. The usage of TIPA counteracted this decline in strength by improving the ferrite hydration and increasing the optimum amount of gypsum required in each composition

  16. Distribution of Hg, As and Se in material and flue gas streams from preheater-precalciner cement kilns and vertical shaft cement kilns in China.

    Science.gov (United States)

    Yan, Dahai; Peng, Zheng; Ding, Qiong; Karstensen, Kåre Helge; Engelsen, Christian J; Li, Li; Ren, Yong; Jiang, Chen

    2015-08-01

    The aim of this study was to evaluate the behavior of Hg, As, and Se in cement production. Two types of cement plants were studied, including the vertical shaft kiln (VSK) and preheater-precalciner kiln (PPK) processes. Determination of Hg, As, and Se in the main material and gas streams were performed. It was found that recycling of particulate matter captured by an air pollution control device caused a significant enrichment of Hg and As inside both processes. The total quantity of Hg entering the process and the quantity emitted to the atmosphere were found to be 10-109 and 6.3-38 mg, respectively, per ton of clinker produced. The average Hg emission was calculated to be around 41% of the total mercury input. The emissions found complied with the European Union (EU) limit and exceeded partly the U.S. limit. Furthermore, it was found that oxidized mercury was the dominant species in the PPK process, whereas the reduced form was dominant in the VSK process, due to the oxidizing and reducing gas conditions, respectively. Regarding the distribution of As and Se, the major amounts were bound to the solid materials, that is, cement clinker and particulate matter. Based on cement production data in China in 2013, the annual emissions of Hg and As were estimated to be in the range of 8.6-52 and 4.1-9.5 tons, respectively.

  17. Development of Corundum—Mullite—Zirconia Clinkers

    Institute of Scientific and Technical Information of China (English)

    LIUXin-yu; SUNGeng-chen; 等

    1994-01-01

    The properties of corundum-mullite-zirco-nia clinkers made by reaction-sintering have been investigated.It is shown that corundum-mullite-zirconia clinkers exhibit lower sintering tempera-ture as well as better thermal shock resistance and corrosion resistance,The carbon-bonded alu-mina-mullite-zirconia material possesses satis-factory properties and may have prospects for application in severe process environments such as continuous casting.

  18. Feasibility of disposing waste glyphosate neutralization liquor with cement rotary kiln.

    Science.gov (United States)

    Bai, Y; Bao, Y B; Cai, X L; Chen, C H; Ye, X C

    2014-08-15

    The waste neutralization liquor generated during the glyphosate production using glycine-dimethylphosphit process is a severe pollution problem due to its high salinity and organic components. The cement rotary kiln was proposed as a zero discharge strategy of disposal. In this work, the waste liquor was calcinated and the mineralogical phases of residue were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD). The mineralogical phases and the strength of cement clinker were characterized to evaluate the influence to the products. The burnability of cement raw meal added with waste liquor and the calorific value of waste liquor were tested to evaluate the influence to the thermal state of the kiln system. The results showed that after the addition of this liquor, the differences of the main phases and the strength of cement clinker were negligible, the burnability of raw meal was improved; and the calorific value of this liquor was 6140 J/g, which made it could be considered as an alternative fuel during the actual production.

  19. CO2 REDUCTION OPTIONS IN CEMENT INDUSTRY - THE NOVI POPOVAC CASE

    Directory of Open Access Journals (Sweden)

    Gordana M Stefanović

    2010-01-01

    Full Text Available The cement industry contributes about 5% to global anthropogenic CO2 emissions, and is thus an important sector in CO2-emission mitigation strategies. Carbon dioxide is emitted from the calcination process of limestone, from combustion of fuels in the kiln, and from the coal combustion during power generation. Strategies to reduce these CO2 emissions include energy efficiency improvement, new processes, shift to low carbon fuels or waste fuels in cement production, increased use of additives in cement production, alternative cements, and CO2 removal from flue gases in clinker kilns. Increased use of fly ash as an additive to cement and concrete has a number of advantages, the primary being reduction of costs of fly ash disposal, resource conservation, and cost reduction of the product. Since the production of cement requires a large amount of energy (about 2.9-3.2 GJt-1, the substitution of cement by fly ash saves not only energy but also reduces the associated greenhouse gas emissions. The paper evaluates the reduction of CO2 emissions that can be achieved by these mitigation strategies, as well as by partial substitution of cement by fly ash. The latter is important because the quality of the produced concrete depends on the physical-chemical properties of the fly ash and thus partial substitution as well as the type of fly ash (e.g., the content of CaO has an effect not only on energy consumption and emissions, but also on the produced concrete quality.

  20. Energy recovery from wastes : experience with solid alternative fuels combustion in a precalciner cement kiln

    OpenAIRE

    Tokheim, Lars-André; Gautestad, Tor; Axelsen, Ernst Petter; Bjerketvedt, Dag

    2001-01-01

    Today virtually all cement clinker burning processes take place in rotary kilns. A mixture of calcareous and argilaceous materials is heated to a temperature of about 1450 °C. In this process decarbonation followed by partial fusion occurs, and nodules of so-called clinker are formed. The cooled clinker is mixed with a few percent of gypsum, and ground into a fine meal – cement. The most modern cement kilns are equipped with a precalciner, in which most of the calcium carbonate...

  1. A New Kind of Eco-Cement Made of Cement Kiln Dust and Granular Blast Furnace Slag

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A research project was conducted to manufacture eco-cement for sustainable development using cement kiln dust( CKD ) and granular blast furnace slag( GBFS ).In the project, the burning process and mineral compositions of CKD clinker were investigated.Dife rent mineralizers such as CaSO4 and CaF2 , sulfur and alkali content were considered.The strength of CKD and GBFS eco-cement were evaluated.The results indicate the CKD clinker can not only form ordinary cement clinker minerals such as C3 S, C2 S and C4 AF, but also form strength to the Portland cement grade 32.5 when blend proportion is properly applied.

  2. Application of multi-block methods in cement production

    DEFF Research Database (Denmark)

    Svinning, K.; Høskuldsson, Agnar

    2008-01-01

    Compressive strength at 1 day of Portland cement as a function of the microstructure of cement was statistically modelled by application of multi-block regression method. The observation X-matrix was partitioned into four blocks, the first block representing the mineralogy, the second particle size...

  3. Guidebook for Using the Tool BEST Cement: Benchmarking and Energy Savings Tool for the Cement Industry

    Energy Technology Data Exchange (ETDEWEB)

    Galitsky, Christina; Price, Lynn; Zhou, Nan; Fuqiu , Zhou; Huawen, Xiong; Xuemin, Zeng; Lan, Wang

    2008-07-30

    The Benchmarking and Energy Savings Tool (BEST) Cement is a process-based tool based on commercially available efficiency technologies used anywhere in the world applicable to the cement industry. This version has been designed for use in China. No actual cement facility with every single efficiency measure included in the benchmark will likely exist; however, the benchmark sets a reasonable standard by which to compare for plants striving to be the best. The energy consumption of the benchmark facility differs due to differences in processing at a given cement facility. The tool accounts for most of these variables and allows the user to adapt the model to operational variables specific for his/her cement facility. Figure 1 shows the boundaries included in a plant modeled by BEST Cement. In order to model the benchmark, i.e., the most energy efficient cement facility, so that it represents a facility similar to the user's cement facility, the user is first required to input production variables in the input sheet (see Section 6 for more information on how to input variables). These variables allow the tool to estimate a benchmark facility that is similar to the user's cement plant, giving a better picture of the potential for that particular facility, rather than benchmarking against a generic one. The input variables required include the following: (1) the amount of raw materials used in tonnes per year (limestone, gypsum, clay minerals, iron ore, blast furnace slag, fly ash, slag from other industries, natural pozzolans, limestone powder (used post-clinker stage), municipal wastes and others); the amount of raw materials that are preblended (prehomogenized and proportioned) and crushed (in tonnes per year); (2) the amount of additives that are dried and ground (in tonnes per year); (3) the production of clinker (in tonnes per year) from each kiln by kiln type; (4) the amount of raw materials, coal and clinker that is ground by mill type (in tonnes per

  4. A Thermoelectric Waste-Heat-Recovery System for Portland Cement Rotary Kilns

    Science.gov (United States)

    Luo, Qi; Li, Peng; Cai, Lanlan; Zhou, Pingwang; Tang, Di; Zhai, Pengcheng; Zhang, Qingjie

    2015-06-01

    Portland cement is produced by one of the most energy-intensive industrial processes. Energy consumption in the manufacture of Portland cement is approximately 110-120 kWh ton-1. The cement rotary kiln is the crucial equipment used for cement production. Approximately 10-15% of the energy consumed in production of the cement clinker is directly dissipated into the atmosphere through the external surface of the rotary kiln. Innovative technology for energy conservation is urgently needed by the cement industry. In this paper we propose a novel thermoelectric waste-heat-recovery system to reduce heat losses from cement rotary kilns. This system is configured as an array of thermoelectric generation units arranged longitudinally on a secondary shell coaxial with the rotary kiln. A mathematical model was developed for estimation of the performance of waste heat recovery. Discussions mainly focus on electricity generation and energy saving, taking a Φ4.8 × 72 m cement rotary kiln as an example. Results show that the Bi2Te3-PbTe hybrid thermoelectric waste-heat-recovery system can generate approximately 211 kW electrical power while saving 3283 kW energy. Compared with the kiln without the thermoelectric recovery system, the kiln with the system can recover more than 32.85% of the energy that used to be lost as waste heat through the kiln surface.

  5. FY 2000 report on the basic survey to promote Joint Implementation, etc. Energy conservation by modernization of a cement plant (Double Horse Cement Co.) in China; 2000 nendo kyodo jisshi nado suishin kiso chosa hokokusho. Chugoku cement kojo (Double Horse Cement) kindaika ni yoru sho energy

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    An investigational study was conducted of possibilities of energy conservation and greenhouse effect gas emission reduction in the cement production process of Double Horse Cement Co., Mianyang City, Sichuan Province, China. Double Horse Cement adopts the wet type long kiln production system and has a production ability of approximately 1.5 million t/y. In the project, as to three production lines out of the six production lines, improvement was planned to be made of the technologies on the following: mixing of raw materials, grinding of raw materials, NSP, clinker cooler, clinker pre-grinder, high-efficiency separator, waste heat use power generation, etc. As a result of the study, it was found that the energy conservation amount obtained was 54,646 toe/y. And, the amount of greenhouse effect gas reduction was 169,086 t-CO2/y. The total fund required for this project was approximately 5.553 billion yen and the internal earning rate was 7.36% after tax. When the project is carried out, expenses vs. effects are 9.8 toe/million yen in energy conservation amount and 30.4 t-CO2/million yen in greenhouse effect gas reduction. (NEDO)

  6. Comparison of Temperature Field Distribution between Cement Preclinkering Technology and Cement Precalcining Technology

    Institute of Scientific and Technical Information of China (English)

    XU Xun; WANG Lan

    2016-01-01

    Through the comparison of calcination conditions between cement preclinkering technology and cement precalcining technology, we studied the characteristics of temperature ifeld distribution of cement preclinkering technology systems including cyclone preheater, preclinkering furnace, and rotary kiln. We used numerical simulation method to obtain data of temperature ifeld distribution.Some results are found by system study. The ratio of tail coal of cement preclinkering technology is about 70%, and raw meal temperature can reach 1070℃. ShorterL/D kiln type of preclinkering technology can obtain more stable calcining zone temperature. The highest solid temperature of cement preclinkering technology is higher than 80℃, and high temperature region (>1450℃) length is 2 times, which is beneifcial for calcining clinker and higher clinker quality. So cement preclinkering technology can obtain more performance temperature ifled, which improves both the solid-phase reaction and liquid-phase reaction.

  7. Biphasic products of dicalcium phosphate-rich cement with injectability and nondispersibility

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Chia-Ling [Advanced Medical Devices and Composites Laboratory, Department of Fiber and Composite Materials, Feng Chia University, Taichung, 407, Taiwan (China); Dental Medical Devices and Materials Research Center, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Chen, Jian-Chih [Department of Orthopaedics, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan (China); Department of Orthopaedics, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Hung, Chun-Cheng; Wang, Jen-Chyan [Dental Medical Devices and Materials Research Center, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Department of Dentistry, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan (China); Tien, Yin-Chun [Department of Orthopaedics, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan (China); Department of Orthopaedics, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Chen, Wen-Cheng, E-mail: wencchen@fcu.edu.tw [Advanced Medical Devices and Composites Laboratory, Department of Fiber and Composite Materials, Feng Chia University, Taichung, 407, Taiwan (China)

    2014-06-01

    In this study, a calcium phosphate cement was developed using tetracalcium phosphate and surface-modified dicalcium phosphate anhydrous (DCPA). This developed injectable bone graft substitute can be molded to the shape of the bone cavity and set in situ through the piping system that has an adequate mechanical strength, non-dispersibility, and biocompatibility. The materials were based on the modified DCPA compositions of calcium phosphate cement (CPC), where the phase ratio of the surface-modified DCPA is higher than that of the conventional CPC for forming dicalcium phosphate (DCP)-rich cement. The composition and morphology of several calcium phosphate cement specimens during setting were analyzed via X-ray diffractometry and transmission electron microscopy coupled with an energy dispersive spectroscopy system. The compressive strength of DCP-rich CPCs was greater than 30 MPa after 24 h of immersion in vitro. The reaction of the CPCs produced steady final biphasic products of DCPs with apatite. The composites of calcium phosphate cements derived from tetracalcium phosphate mixed with surface-modified DCPA exhibited excellent mechanical properties, injectability, and interlocking forces between particles, and they also featured nondispersive behavior when immersed in a physiological solution. - Highlights: • Bone cement precursor with nanocrystals is characterized. • DCP-rich CPCs with nanocrystals exhibited biphasic product phases. • Nanocrystals in cement significantly affected the interlocking ability. • Nanocrystals in cement exhibited higher strength and anti-dispersion. • DCP-rich CPCs increase the potential of bioresorption after reaction.

  8. Full phase analysis of portland clinker by penetrating synchrotron powder diffraction.

    Science.gov (United States)

    de la Torre, A G; Cabeza, A; Calvente, A; Bruque, S; Aranda, M A

    2001-01-15

    Fabrication of portland cements commonly depends on X-ray fluorescence (XRF), which measures the elemental compositions. XRF is used to adjust the raw material proportions and to control the process conditions. However, to predict the mechanical strength of the resulting concrete, it is essential to know the phase composition which is, so far, indirectly inferred by the Bogue method. Here, we report a phase analysis of an industrial portland clinker containing six crystalline phases, Ca3SiO5, Ca2SiO4, Ca4Al2Fe2O10, Ca3Al2O6, NaK3(SO4)2, and CaO, by Rietveld refinement of synchrotron X-ray powder diffraction data (lambda = 0.442377 A). Even the minor component, CaO 0.45(2)%, was readily analyzed. We have also carried out a phase study of the same clinker with laboratory X-rays to characterize the changes in the detection limit and errors. Furthermore, by adding a suitable crystalline standard to the same clinker, we have determined the overall amorphous phase content. The procedure established for this state-of-the-art phase analysis shows the high precision that can be achieved by using penetrating X-rays, which is of interest not only in cement chemistry but in other industrially important multiphase systems such as slags, superalloys, or catalysts.

  9. Synthesis and mechanical properties of a calcium sulphoaluminate cement made of industrial wastes

    Directory of Open Access Journals (Sweden)

    Gallardo, M.

    2014-09-01

    Full Text Available Environmentally-friendly calcium sulphoaluminate clinkers were obtained from a mixture of aluminium dross, fluorgypsum, fly ash and CaCO₃ at temperatures within the range of 1100 to 1400 °C. After the heat treatments Ca₄Al₆O₁₂SO₄ was the main phase. Three different cements were prepared using the clinkers synthesized at 1250, 1350 and 1400 °C; the clinker powders were mixed with 20 wt% of hemihydrate. Cement pastes were prepared using a water/cement ratio (w/c, 0.4 followed by curing at 20 or 40 °C for periods of time ranging from 1 to 28 days. Most of the samples showed high compression strengths 40–47 MPa after 28 days, which were comparable to the strength of Portland cement. Ettringite was the main hydration product and its morphology consisted of acicular and hexagonal plates, which is typical of this phase.Se fabricaron clinkers de bajo impacto ambiental a base de sulfoaluminato de calcio calcinando mezclas de escoria de aluminio, fluoryeso, ceniza volante y CaCO₃ a diferentes temperaturas dentro de un rango de 1100 a 1400 °C. Se observó la formación de Ca₄Al₆O₁₂SO₄ como fase principal. Para obtener los cementos, los clinkers obtenidos a 1250, 1350 y 1400 °C se mezclaron con 20% en peso de hemihidrato. Se prepararon pastas usando una relación agua/cemento, de 0.4 y se curaron a 20 y 40 °C por diferentes periodos de tiempo desde 1 hasta 28 días. Los valores de resistencia a la compresión a los 28 días de curado de la mayoría de las muestras estuvieron entre 40–47 MPa, equiparables a los de referencia de pastas de cemento Portland. La etringita fue el principal producto de hidratación y su morfología consistió de placas hexagonales y aciculares, típicas de esta fase.

  10. Action-Dependent Adaptive Critic Design Based Neurocontroller for Cement Precalciner Kiln

    Directory of Open Access Journals (Sweden)

    Baosheng Yang

    2009-10-01

    Full Text Available There are many factors that can affect the calciner process of cement production, such as highly nonlinearity and time-lag, making it very difficult to establish an accurate model of the cement precalciner kiln (PCK system. In order to reduce transport energy consumption and to ensure the quality of cement clinker burning, one needs to explore different control methods from the traditional way. Adaptive Critic Design (ACD integrated neural network, reinforcement learning and dynamic programming techniques, is a new optimal method. As the PCK system parameters change frequently with high real-time property, ADACD (Action-Dependant ACD algorithm is used in PCK system to control the temperature of furnace export and oxygen content of exhaust. ADACD does not depend on the system model, it may use historical data to train a controller offline, and then adapt online. Also the BP network of artificial neural network is used to accomplish the network modeling, and action and critic modules of the algorithm. The results of simulation show that, after the fluctuations in the early control period, the controlled parameters tend to be stabilized guaranteeing the quality of cement clinker calcining.

  11. An assessment of gas-side fouling in cement plants

    Science.gov (United States)

    Marner, W. J.

    1982-01-01

    The cement industry is the most energy-intensive industry in the United States in terms of energy cost as a percentage of the total product cost. An assessment of gas-side fouling in cement plants with special emphasis on heat recovery applications is provided. In the present context, fouling is defined as the buildup of scale on a heat-transfer surface which retards the transfer of heat and includes the related problems of erosion and corrosion. Exhaust gases in the cement industry which are suitable for heat recovery range in temperature from about 100 to 1300 K, are generally dusty, may be highly abrasive, and are often heavily laden with alkalies, sulfates, and chlorides. Particulates in the exhaust streams range in size from molecular to about 100 micrometers in diameter and come from both the raw feed as well as the ash in the coal which is the primary fuel used in the cement industry. The major types of heat-transfer equipment used in the cement industry include preheaters, gas-to-air heat exchangers, waste heat boilers, and clinker coolers. At the present time, the trend in this country is toward suspension preheater systems, in which the raw feed is heated by direct contact with the hot kiln exit gases, and away from waste heat boilers as the principal method of heat recovery. The most important gas-side fouling mechanisms in the cement industry are those due to particulate, chemical reaction, and corrosion fouling.

  12. Potential for energy conservation in the cement industry

    Energy Technology Data Exchange (ETDEWEB)

    Garrett-Price, B.A.

    1985-02-01

    This report assesses the potential for energy conservation in the cement industry. Energy consumption per ton of cement decreased 20% between 1972 and 1982. During this same period, the cement industry became heavily dependent on coal and coke as its primary fuel source. Although the energy consumed per ton of cement has declined markedly in the past ten years, the industry still uses more than three and a half times the fuel that is theoretically required to produce a ton of clinker. Improving kiln thermal efficiency offers the greatest opportunity for saving fuel. Improving the efficiency of finish grinding offers the greatest potential for reducing electricity use. Technologies are currently available to the cement industry to reduce its average fuel consumption per ton by product by as much as 40% and its electricity consumption per ton by about 10%. The major impediment to adopting these technologies is the cement industry's lack of capital as a result of low or no profits in recent years.

  13. A Concept for Rapid Repair of Bomb-Damaged Runways Using Regulated-Set Cement

    Science.gov (United States)

    1975-07-01

    TAlo0 .CaX , in which X is a halogen; the cement can also be a blended cement produced by grinding together portland - ceraent clinker and a...than those used for portland cement. The accel- erated setting time of the cement is achieved by burning into the cement clinker a controlled amount...4,779, 26 April 1971 British Patent No. 1,311,^25, 25 July 1973 Indian Patent No. 133,6Ul, 5 July 197^ South African Patent No. 3069/71, 3 May 1972

  14. Potentials of making active belite cements with chromium oxide as modifier

    Energy Technology Data Exchange (ETDEWEB)

    Subba Rao, V.V.; Narang, K.C.

    1987-08-01

    One of the ways to conserve energy and high-grade raw materials is to make cements with modified mineral structure, in particular with highly reactive belite content. The potential for making active belite cement with chromium oxide modifier appears to be promising. The cements made with chromium oxide (upto 7%) modified clinkers show good early and ultimate strength development and are observed to be sound. The chromium oxide modified belite cements do not undergo inversion and can be made at relatively lower temperatures. The most important parameter for the manufacture of such cements is the control on alite content in the clinker, which should either be absent or near zero level.

  15. Model of clinker capacity expansion

    CSIR Research Space (South Africa)

    Stylianides, T

    1998-10-01

    Full Text Available recently be- come more relevant in South Africa as a result of the creation of a more competitive nvironment following the recommendation f the Competition Board - and approval by the Minister of Trade and Industries - to disband the cement cartel...

  16. Material Characteristics of Clinker Ash and Examination of Applicability for Embankment

    Science.gov (United States)

    Wakatsuki, Yoshitaka; Hyodo, Masayuki; Yoshimoto, Norimasa; Nakashita, Akifumi; Ikeda, Takashi

    2009-06-01

    The clinker ash is a coal ash generated by the coal-fired power station. It is characterized by its lightweight particle with asperity due to foaming during production process resulted in high shear stiffness and strength and high permeability. It is, therefore, increasingly used for the embankment material, the base course material, and the drainage material. Moreover, the application has started to be investigated for the vertical drain method and the compaction pile method. However, the physical characteristics and the mechanical characteristics of clinker ash have not been understood yet. It is expected that the stock yard for coal ashes will be insufficient as production of the coal ash will increase. It is necessary to use the coal ash more to maintain the global environment. The design parameter for clinker ash to apply to the embankment material was experimentally investigated in this research.

  17. The mineralogy and chemistry of cement and cement raw materials In the united arab emirates

    OpenAIRE

    Nasir, Sobhi J. [صبحي جابر نصر; El Etr, H.

    1996-01-01

    The raw materials, clinkers and cements from different cement factories in the United Arab Emirates have been investigated using polarizing microscopy, X-ray diffraction (XRD), Scanning electron microscopy (SEM), and chemical analyses. The chemical and mineralogical analyses indicate that the local raw materials are suitable for cement industry. Geological review shows that there is a good potential for industrial-grade local occurrences of limestone, marl, gypsum and iron oxide, that may be ...

  18. Review of technologies for mercury removal from flue gas from cement production processes

    DEFF Research Database (Denmark)

    Zheng, Yuanjing; Jensen, Anker Degn; Windelin, Christian

    2012-01-01

    Mercury is a pollutant of concern and mercury emissions from cement plants are under environmental regulation. After coal-fired power plants, mercury emissions from cement and mineral production are the second largest anthropogenic sources. Compared to fuels, cement raw materials are the major....... The sorbent injection system should be installed downstream of the main kiln filter and upstream of a new added polishing fabric filter to avoid the cement kiln dust recycling and disposal issues. To reduce the sorbent cost and possible disposal expense, non-carbon based sorbents that could be added to cement...... or regenerated in-situ are desired and should be developed.Various mathematical models have been developed to simulate mercury removal in fixed-bed reactors and by sorbent injection upstream of a fabric filter. The fabric filter adsorption models use the adsorption isotherms coupled with diffusion in the sorbent...

  19. International development trends in low-energy cements

    Energy Technology Data Exchange (ETDEWEB)

    Stark, J.; Mueller, A.

    1988-04-01

    Besides the currently dominant tendency to increase the proportion of interground additive in cement, the following development trends are internationally emerging in the material composition of so-called low-energy cements with a view to minimizing energy input for cement manufacture: (1) active belite cement with the principal clinker minerals a'C/sub 2/S and C/sub 3/S; (2) belite sulphoaluminate cement (..beta.. C/sub 2/S, C/sub 4/A/sub 3/S); (3) belite sulphoferrite cement (..beta.. C/sub 2/S, C/sub 4/AF, C/sub 4/A/sub 3/S); (4) NTS cement (alinite).

  20. Use of waste brick as a partial replacement of cement in mortar.

    Science.gov (United States)

    Naceri, Abdelghani; Hamina, Makhloufi Chikouche

    2009-08-01

    The aim of this study is to investigate the use of waste brick as a partial replacement for cement in the production of cement mortar. Clinker was replaced by waste brick in different proportions (0%, 5%, 10%, 15% and 20%) by weight for cement. The physico-chemical properties of cement at anhydrous state and the hydrated state, thus the mechanical strengths (flexural and compressive strengths after 7, 28 and 90 days) for the mortar were studied. The microstructure of the mortar was investigated using scanning electron microscopy (SEM), the mineralogical composition (mineral phases) of the artificial pozzolan was investigated by the X-ray diffraction (XRD) and the particle size distributions was obtained from laser granulometry (LG) of cements powders used in this study. The results obtained show that the addition of artificial pozzolan improves the grinding time and setting times of the cement, thus the mechanical characteristics of mortar. A substitution of cement by 10% of waste brick increased mechanical strengths of mortar. The results of the investigation confirmed the potential use of this waste material to produce pozzolanic cement.

  1. 76 FR 34252 - Notice Pursuant to the National Cooperative Research and Production Act of 1993; Portland Cement...

    Science.gov (United States)

    2011-06-13

    ... Cement Association Notice is hereby given that, on May 12, 2011, pursuant to Section 6(a) of the National Cooperative Research and Production Act of 1993, 15 U.S.C. 4301 et seq. (``the Act''), Portland Cement... specified circumstances. Specifically, Drake Cement, LLC, Scottsdale, AZ; Argos USA Corporation, Houston,...

  2. Modelling the effects of waste components on cement hydration

    NARCIS (Netherlands)

    Eijk, van R.J.; Brouwers, H.J.H.

    2001-01-01

    Ordinary Portland Cement (OPC) is often used for the solidification/stabilization (S/S) of waste containing heavy metals and salts. These waste components will precipitate in the form of insoluble compounds on to unreacted cement clinker grains preventing further hydration. In this study the long te

  3. Modelling the effects of waste components on cement hydration

    NARCIS (Netherlands)

    Eijk, van R.J.; Brouwers, H.J.H.

    2000-01-01

    Ordinary Portland Cement (OPC) is often used for the Solidification/Stabilization (S/S) of waste containing heavy metals and salts. These waste componenents will precipitate in the form of insoluble compounds onto unreacted cement clinker grains preventing further hydration. In this study the long t

  4. Environmental impact assessment of combustible wastes utilization in rotary cement kilns

    OpenAIRE

    2013-01-01

    This study focuses on the environmental impact assessment of the coal combustion and its substitution by alternative fuels from combustible wastes during Portland cement clinker sinterization in rotary cement kiln. Environmental impact assessment was carried out based on the fuels chemical composition and operating parameters of a rotary cement kiln in accordance with EURITS and IMPACT 2002+ methods.

  5. High belite cement from alternative raw materials

    Directory of Open Access Journals (Sweden)

    Ghorab, H. Y.

    2014-05-01

    Full Text Available Three high belite laboratory clinkers were prepared from traditional and alternative raw materials. Reference clinker was obtained from 77% limestone, 11% sandy clays, 11% fatty clays and 1% iron scales. The fatty clays were replaced by red brick powder in the raw meal of the second clinker and were lowered to 2% with the replacement of 10% of the limestone by egg shells in the third clinker. The SEM examination revealed clear presence of crossed striae and twinning in the rounded belite grains of the reference clinker caused by the transformation of the α´-belite to the β polymorph. Striae were weaker in the second and third clinkers indicating a probable stabilization of the α ‘-belite polymorph. Compressive strength of the respective cements were attained first after 28 days and the early strength did not improve with increasing fineness. Higher compressive strength values were found for the cement prepared from second clinker.Se han preparado tres clinkeres de laboratorio con altos contenidos en belita a partir de materias primas tradicionales y alternativas. El clinker de referencia se obtuvo a partir de una mezcla de caliza, arcillas arenosas y grasas y limaduras de hierro. Las arcillas grasas fueron sustituidas por polvo de ladrillo rojo en la preparación del segundo clinker, y en el tercero el contenido de arcilla grasa fue de solo un 2% y parte de la caliza fue sustituida por cascara de huevo. El estudio realizado por SEM muestra superficies estriadas alrededor de los granos de belita que indican una transformación del polimorfo α´ a la forma β-C₂S, durante el enfriamiento. Esas estrías son menos marcadas en el segundo y tercer clinker, indicando, una estabilización del polimorfo α´-C₂S. Los valores de resistencias a compresión de los correspondientes cementos, a 28 días de curado, no se ven incrementados por la finura de dichos cementos. Las mayores resistencias se obtuvieron en el cemento preparado a partir del cl

  6. Characterisation of Cements From Dominantly Volcanic Raw Materials of the Carpathian Bend Zone

    Directory of Open Access Journals (Sweden)

    Halmagy Timea

    2016-12-01

    Full Text Available This paper presents the results of laboratory investigations regarding the production of cements from local raw materials, such as limestone from Varghis, gypsum from Nucsoara, basaltic scoria from Racosul de Jos, volcanic tuff from Racosul de Sus, diatomite from Filia, and red mud from Oradea. The raw mixtures, based on modified Bogue calculations, contain limestone, gypsum, and one or two of the above-mentioned materials. The cements resulted from clinker grinding in a laboratory gas furnace at 1260-1300 °C, with one hour at the peak temperatures, and were characterised for Blaine specific surface area, specific density, and mineral phases. Physico-mechanical properties, such as water content for normal consistency, setting time, soundness, and compressive strength were also determined. Results show that these cements contain belite, ferrite, calcium sulphoaluminate, anhydrite, and some minor compounds.

  7. FY 1998 annual report on power generation by waste heat from cement production in China; Chugoku ni okeru cement hainetsu hatsuden 1998 nendo chosa hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    This project is to implement a feasibility study for applying waste heat power generation, which have been already commercialized in Japan and producing remarkable results, to China's cement plants producing 3,500 t/d or more of clinker, and thereby to try to establish a link with the Japan's clean development mechanism. It is expected that introduction of these systems improves energy use efficiency and environments in China. The study results indicate that the project for a Tongling Conch plant could generate power of 15,000 kW, reducing CO2 emissions by 89,178 t/y and cumulatively 1,783,560 tons in the 20-year period. The results also indicate that the project will be highly profitable, with an estimated internal return rate of as high as 33.78%. The project for a Huaxin plant could generate power of 8,400 kW, reducing CO2 emissions by 48,412 t/y and cumulatively 968,240 tons in the 20-year period, annually saving power charges by 325 million yen and bringing an internal return rate of 10.72%. (NEDO)

  8. Evaluating the thermal stability of mercury and other metals in coal combustion residues used in the production of cement clinker, asphalt, and wallboard

    Science.gov (United States)

    Research is underway by the U.S. Environmental Protection Agency (EPA) to document any changes that may occur to coal combustion residues (CCRs) as a result of implementation of mercury and multiipollutant control technology at coal-fired power plants. This work was cited as a pr...

  9. Degradation of Alumina and Magnesia Chrome refractory bricks in Portland cement kiln – Corrected version*

    Directory of Open Access Journals (Sweden)

    Ben Addi K.

    2014-05-01

    Full Text Available In cement plants, the refractory products are particularly confronted to partially liquid oxide phases at temperature ranging between 900°C and 1700°C. All constituents of these products have to resist not only to thermal constraints, but also to the thermochemical solicitations which result from contact material/coating. In order to study the phenomenon of degradation of refractory bricks in cement kilns and to identify the causes of their degradation, we proceed to the examination of industrial cases in cement kiln. Many chemical tests of the degraded refractory bricks have been done and the results acquired were compared to the ones not used. The analysis of the results is doing using different techniques (Loss of ignition, X-ray Fluorescence, X-ray Diffraction. The results show that the degradation of the used bricks in the clinkering and cooling zone is due to the infiltration of aggressive elements such us sulphur, alkali (Na2O, K2O .... The chemical interaction between the Portland clinker phases and refractory material has also an importance on the stability of the coating and consequently on the life of the refractories.

  10. Blended Cements Produced With Synthetic Zeolite Made from Industrial By-Product

    Directory of Open Access Journals (Sweden)

    Vitoldas Vaitkevičius

    2015-03-01

    Full Text Available Zeolites are appropriate supplementary cementitious materials in cement and concrete industry. In the present work synthetic zeolites was used like supplementary material in hardened cement paste and some properties as well as its influence on Portland cement hydration was determinate. X-ray powder diffraction, scanning electronic microscopy and energy-dispersive X-ray spectroscopy, FTIR spectroscopy were used as investigation methods. The compressive strength of hardened cement paste was measured at day 3, 28 and 60. The instrumental analysis showed that zeolite A(Na dominates and unreacted Al(OH3 remains in investigated synthetics zeolites, made from thermal and mechanical treated AlF3 production waste. The Chapelle test showed that both zeolites have good pozzolanic properties. The samples compressive strength remained close to the control samples compressive strength, reducing the amount of Portland cement, i.e., changing it by zeolite. After 60 days, the compressive strength was the best in the samples where 5% of Portland cement was replaced by the 2-zeolite. The compressive strength of the samples increased by 9 % compared with control samples. This research provides a real opportunity to save cement thus disposing the waste.DOI: http://dx.doi.org/10.5755/j01.ms.21.1.5635

  11. Integration of oxygen membranes for oxygen production in cement plants

    DEFF Research Database (Denmark)

    Puig Arnavat, Maria; Søgaard, Martin; Hjuler, Klaus;

    2015-01-01

    The present paper describes the integration of oxygen membranes in cement plants both from an energy, exergy and economic point of view. Different configurations for oxygen enrichment of the tertiary air for combustion in the pre-calciner and full oxy-fuel combustion in both pre-calciner and kiln...

  12. Utilization of alternative fuels and the additions to the clinker as opportunities of reductions of greenhouse gas emissions - an overview of the cement sector in Brazil; A utilizacao de combustiveis alternativos e de adicoes ao clinquer como oportunidades de reducao de emissoes de gases de efeito estufa - um panorama do setor de cimento no Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Wills, William [Universidade Federal do Rio de Janeiro (PPE/COPPE/UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-Graduacao de Engenharia. Programa de Planejamento Energetico], E-mail: wwills@lima.coppe.ufrj.br; La Rovere, Emilio Lebre; Westin, Fernanda Fortes [Universidade Federal do Rio de Janeiro (LIMA/COPPE/UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-Graduacao de Engenharia. Lab. Interdisciplinar de Meio Ambiente], Emails: emlio@ppe.ufrj.br, fforteswestin@yahoo.com.br

    2010-07-01

    This paper analyses the energy consumption of the sector in Brazil, specially the participation of alternative sources which are growing systematically since 2001, and the addition of the clinker which is a practice that allows to reduce the CO{sub 2} emissions. These options allows to reduce the burning of fossil fuels and the pollutant emission, reducing local, regional and global impacts.

  13. Development of converter operation technology using ironbearing concentrates and clinker-steel cakes

    Science.gov (United States)

    Protopopov, E. V.; Feyler, S. V.; Amelin, A. V.; Chumov, E. P.

    2016-09-01

    Technological process of steel production in converters using clinker-steel cakes and iron-bearing concentrates of “EVRAZ ZSMK” JSC slag processing unit ensuring liquid-phase reduction of iron from oxides is designed. Developed technology allows implementation of iron-containing materials recycling, reduces consumption of scrap, increases liquid metal yield, improves environmental safety in the region.

  14. Hydration of Hybrid Alkaline Cement Containing a Very Large Proportion of Fly Ash: A Descriptive Model

    Directory of Open Access Journals (Sweden)

    Inés Garcia-Lodeiro

    2016-07-01

    Full Text Available In hybrid alkaline fly ash cements, a new generation of binders, hydration, is characterized by features found in both ordinary portland cement (OPC hydration and the alkali activation of fly ash (AAFA. Hybrid alkaline fly ash cements typically have a high fly ash (70 wt % to 80 wt % and low clinker (20 wt % to 30 wt % content. The clinker component favors curing at ambient temperature. A hydration mechanism is proposed based on the authors’ research on these hybrid binders over the last five years. The mechanisms for OPC hydration and FA alkaline activation are summarized by way of reference. In hybrid systems, fly ash activity is visible at very early ages, when two types of gel are formed: C–S–H from the OPC and N–A–S–H from the fly ash. In their mutual presence, these gels tend to evolve, respectively, into C–A–S–H and (N,C–A–S–H. The use of activators with different degrees of alkalinity has a direct impact on reaction kinetics but does not modify the main final products, a mixture of C–A–S–H and (N,C–A–S–H gels. The proportion of each gel in the mix does, however, depend on the alkalinity generated in the medium.

  15. Optimum feeding rate of solid hazardous waste in a cement kiln burner

    Directory of Open Access Journals (Sweden)

    W.K. Hiromi Ariyaratne, Morten C. Melaaen, Lars-André Tokheim

    2013-01-01

    Full Text Available Solid hazardous waste mixed with wood chips (SHW is a partly CO2 neutral fuel, and hence is a good candidate for substituting fossil fuels like pulverized coal in rotary kiln burners used in cement kiln systems. SHW is used in several cement plants, but the optimum substitution rate has apparently not yet been fully investigated. The present study aims to find the maximum possible replacement of coal by SHW, without negatively affecting the product quality, emissions and overall operation of the process. A full-scale experiment was carried out in the rotary kiln burner of a cement plant by varying the SHW substitution rate from 0 to 3 t/hr. Clinker quality, emissions and other relevant operational data from the experiment were analysed using fuel characteristics of coal and SHW. The results revealed that SHW could safely replace around 20% of the primary coal energy without giving negative effects. The limiting factor is the free lime content of the clinker. Results from the present study were also compared with results from a previous test using meat and bone meal.

  16. Optimum feeding rate of solid hazardous waste in a cement kiln burner

    Energy Technology Data Exchange (ETDEWEB)

    Ariyaratne, W.K. Hiromi; Melaaen, Morten C.; Tokheim, Lars-Andre [Telemark University College, Faculty of Technology, Kjoelnes Ring 56, P.O. Box 203, N-3901, Porsgrunn (Norway)

    2013-07-01

    Solid hazardous waste mixed with wood chips (SHW) is a partly CO2 neutral fuel, and hence is a good candidate for substituting fossil fuels like pulverized coal in rotary kiln burners used in cement kiln systems. SHW is used in several cement plants, but the optimum substitution rate has apparently not yet been fully investigated. The present study aims to find the maximum possible replacement of coal by SHW, without negatively affecting the product quality, emissions and overall operation of the process. A full-scale experiment was carried out in the rotary kiln burner of a cement plant by varying the SHW substitution rate from 0 to 3 t/hr. Clinker quality, emissions and other relevant operational data from the experiment were analysed using fuel characteristics of coal and SHW. The results revealed that SHW could safely replace around 20% of the primary coal energy without giving negative effects. The limiting factor is the free lime content of the clinker. Results from the present study were also compared with results from a previous test using meat and bone meal.

  17. Operating experience with CFB technology for waste utilization at a cement production plant

    Energy Technology Data Exchange (ETDEWEB)

    Wirthwein, R.; Scur, P.; Scharf, K.F. [Rudersdorfer Zement GmbH, (Germany); Hirschfelder, H. [Lurgi Energie und Entsorgung GmbH, (Germany)

    2002-07-01

    The Rudersdorf cement plant in Germany strives for high environmental standards, a high quality product and low production costs. The plant was the first to use circulating fluidized bed (CFB) technology in combination with a cement kiln. The following objectives were defined for the CFB: (1) use of waste as a low-cost raw materials and fuel for cement production, (2) ensure good combustion conditions even when using low quality fuels, and (3) produce raw material components which can be homogeneously integrated into the cement kiln feed stream. A gasification process was developed for processing a diverse waste stream to produce lean gas for use as a secondary fuel along with an inert ash that serves as a raw material component. The CFB unit was put into service in 1996. Since its launch, various plant components and waste pre-processing equipment have been optimized. The CFB unit has an availability of more than 90 per cent, and can process 120,000 tpa of secondary fuels, 150,000 tpa of ash, and 50,000 tpa of other mineral residues. Its use has contributed significantly to fuel costs savings and improved environmental performance at the cement production plant. 9 figs.

  18. ROTARY SCREW SYSTEMS IN CEMENT

    OpenAIRE

    2016-01-01

    The article presents results of research of rotary-screw systems in relation to the creation of rotary kilns for the annealing of-cuttings in the preparation of cement clinker. Using the proposed design, in comparison with known designs of similar purpose, it significantly improves performance, reduces size and power consumption through the use of rotary screw systems in the form of screw rotors and drums made hollow with sidewalls assembled from separate strips or plates of different geometr...

  19. TECHNOLOGY AND EFFICIENCY IN USAGE OF BROWN COAL ASH FOR CEMENT AND CONCRETE MIXTURES AT THE LELCHITSKY DEPOSIT

    Directory of Open Access Journals (Sweden)

    G. D. Lyahevich

    2017-01-01

    Full Text Available Modern visions on the role of high-dispersity additives in concrete mixtures reflect a positive effect of optimal amount of ash left after combustion of solid fuel on structure and physico-mechanical characteristics of cement compositions: hardening of contact zone between cement stone and aggregates with formation of “binder – aggregate” clusters due to high surface energy of aggregate particles; reduction of total cement stone porosity in concrete while increasing volumetric concentration and aggregate dispersion; binding of calcium hydroxide by amorphized silicon of pozzolanic aggregates; increase in pozzolanic aggregate activity with its fine grinding, etc. Experimental investigations have ascertained that usage of portland cement clinker ash samples left after brown coal burning at the Lelchitsky deposit contributed to an increase of cement working life and activity. Concrete samples have been obtained that have improved physico-mechanical properties owing to introduction the following components in their composition: 2–14 % (of cement mass of ash left after brown coal burning and 1.6–2.1 % of sodium salt that is a condensation product of sulfur oxidate in aromatic hydrocarbons with formaldehyde. Efficiency of the executed work has been proved by solution of the problems pertaining to an increase of neat cement working life, cement activity, concrete strength. The paper also considers no less important problem concerning protection of the environment from contamination with ash left after burning of high-ash brown coal. 

  20. Through Lean Manufacturing Techniques Improvement InProduction of Cement Plant

    Directory of Open Access Journals (Sweden)

    Udai Singh Chouhan

    2016-07-01

    Full Text Available The production of cement is a process industry which is distinct from manufacturing and the main objective here is to apply lean manufacturing technique to the eradicate waste to the processes and parameters which are common between process and discrete manufacturing. Lean signifies a major advance over traditional mass production methods. Value stream mapping is used first to identify different waste present in the current state. This paper will describe work undertaken investigating the application of lean thinking to a continuous production environment, in this instance exemplified by the cement industry. Implementation of lean helps many organizations to improve their productivity and efficiency Cement plays a vital role in economic development of any country. Having more than a hundred and fifty years history, it has been used extensively in construction of anything, from a small building to a mammoth multi-purpose project. The need for improving the efficiency of the cement production line is widely acknowledged in order to reduce the downtime rates, and satisfy high levels of market demand where the demand for cement is mostly second substance behind water. This paper articulates a methodology for data collection, knowledge extraction, model creation and experimentation that combines the use of process mapping, computational simulation. A detailed description of each step of the process is given and is illustrated by results from a case study undertaken during the research. This paper describes work undertaken to implement lean practices in the continuous process sector as represented by cement production. One of the major barriers to lean implementation is providing evidence of its potential benefit to end-users. This work aims to overcome this obstacle by producing a tool which can be used to easily visualize the benefits of adopting lean practices without requiring disruption to the production environment

  1. Alternative Fuel for Portland Cement Processing

    Energy Technology Data Exchange (ETDEWEB)

    Schindler, Anton K; Duke, Steve R; Burch, Thomas E; Davis, Edward W; Zee, Ralph H; Bransby, David I; Hopkins, Carla; Thompson, Rutherford L; Duan, Jingran; ; Venkatasubramanian, Vignesh; Stephen, Giles

    2012-06-30

    The production of cement involves a combination of numerous raw materials, strictly monitored system processes, and temperatures on the order of 1500 °C. Immense quantities of fuel are required for the production of cement. Traditionally, energy from fossil fuels was solely relied upon for the production of cement. The overarching project objective is to evaluate the use of alternative fuels to lessen the dependence on non-renewable resources to produce portland cement. The key objective of using alternative fuels is to continue to produce high-quality cement while decreasing the use of non-renewable fuels and minimizing the impact on the environment. Burn characteristics and thermodynamic parameters were evaluated with a laboratory burn simulator under conditions that mimic those in the preheater where the fuels are brought into a cement plant. A drop-tube furnace and visualization method were developed that show potential for evaluating time- and space-resolved temperature distributions for fuel solid particles and liquid droplets undergoing combustion in various combustion atmospheres. Downdraft gasification has been explored as a means to extract chemical energy from poultry litter while limiting the throughput of potentially deleterious components with regards to use in firing a cement kiln. Results have shown that the clinkering is temperature independent, at least within the controllable temperature range. Limestone also had only a slight effect on the fusion when used to coat the pellets. However, limestone addition did display some promise in regards to chlorine capture, as ash analyses showed chlorine concentrations of more than four times greater in the limestone infused ash as compared to raw poultry litter. A reliable and convenient sampling procedure was developed to estimate the combustion quality of broiler litter that is the best compromise between convenience and reliability by means of statistical analysis. Multi-day trial burns were conducted

  2. High-volume natural volcanic pozzolan and limestone powder as partial replacements for portland cement in self-compacting and sustainable concrete

    KAUST Repository

    Celik, Kemal

    2014-01-01

    A laboratory study demonstrates that high volume, 45% by mass replacement of portland cement (OPC) with 30% finely-ground basaltic ash from Saudi Arabia (NP) and 15% limestone powder (LS) produces concrete with good workability, high 28-day compressive strength (39 MPa), excellent one year strength (57 MPa), and very high resistance to chloride penetration. Conventional OPC is produced by intergrinding 95% portland clinker and 5% gypsum, and its clinker factor (CF) thus equals 0.95. With 30% NP and 15% LS portland clinker replacement, the CF of the blended ternary PC equals 0.52 so that 48% CO2 emissions could be avoided, while enhancing strength development and durability in the resulting self-compacting concrete (SCC). Petrographic and scanning electron microscopy (SEM) investigations of the crushed NP and finely-ground NP in the concretes provide new insights into the heterogeneous fine-scale cementitious hydration products associated with basaltic ash-portland cement reactions. © 2013 Published by Elsevier Ltd.

  3. Evaluation of cement production using a pressurized fluidized-bed combustor

    Energy Technology Data Exchange (ETDEWEB)

    DeLallo, M.; Eshbach, R.

    1994-01-01

    There are several primary conclusions which can be reached and used to define research required in establishing the feasibility of using PFBC-derived materials as cement feedstock. 1. With appropriate blending almost any material containing the required cement-making materials can be utilized to manufacture cement. However, extensive blending with multiple materials or the use of ash in relatively small quantities would compromise the worth of this concept. 2. The composition of a potential feedstock must be considered not only with respect to the presence of required materials, but just as significantly, with respect to the presence and concentration of known deleterious materials. 3. The processing costs for rendering the feedstock into an acceptable composition and the energy costs associated with both processing and burning must be considered. It should be noted that the cost of energy to produce cement, expressed as a percentage of the price of the product is higher than for any other major industrial product. Energy consumption is, therefore, a major issue. 4. The need for conformance to environmental regulations has a profound effect on the cement industry since waste materials can neither be discharged to the atmosphere or be shipped to a landfill. 5. Fifth, the need for achieving uniformity in the composition of the cement is critical to controlling its quality. Unfortunately, certain materials in very small concentrations have the capability to affect the rate and extent to which the cementitious compound in portland cement are able to form. Particularly critical are variations in the ash, the sulfur content of the coal or the amount and composition of the stack dust returned to the kiln.

  4. Low SO2 Emission Preheaters for Cement Production

    DEFF Research Database (Denmark)

    Rasmussen, Martin Hagsted

    showed that this figure could be between 90 kJ/mole and 140 kJ/mole, with a corresponding change of preexponential factors. The ability to predict emissions is very important in the design of cement plants. In this thesis the zone model concept has been applied to the modelling of the cyclone stages...... in a preheater tower. The idea is to account for the complex flow pattern in a cyclone stage by dividing it into zones, each zone having special features. In this manner the model can account for gas/solid heat exchange, gas/solid separation, different gas and solid residence times, etc. The model was evaluated...

  5. 75 FR 453 - FLSMidth, Inc., Cement Division, Product Engineering, Including On-Site Leased Workers of Aerotek...

    Science.gov (United States)

    2010-01-05

    ...., Cement Division, Product Engineering, Including On-Site Leased Workers of Aerotek Contract Engineering..., applicable to workers of FLSmidth, Inc., Cement Division, Product Engineering, including on-site leased...-site leased workers from Clarke Consulting, Inc. were also employed on-site at FLSmidth, Inc.,...

  6. Utilization potential of wood clones of Eucalyptus urophylla in the production of wood-cement panels

    Directory of Open Access Journals (Sweden)

    Lourival Marin Mendes

    2011-03-01

    Full Text Available The objective of this study was to evaluate the potential of using clones of Eucalyptus urophylla in the production of wood-cement panels. The study used six clones of Eucalyptus urophylla with 8 years of age, from the Companhia Mineira de Metais, located in Paracatu - MG. For the formation of the panels it was used Portland cement CP V - ARI / Plus, possessing high initial resistance to mineral binder and calcium chloride (CaCl2 as accelerator for the cement curing. The panels were produced with the following parameters: dimensions of 49.5 x 49.5 x 1.5 cm, nominal density of 1.2 g/cm ³, relation wood: cement (1:2.5 and relation water: cement (1:1.5. The results can showed that: (1 for thickness swelling in two and twenty-four hours, only clones 19.28 and 58 attended the specifications, (2 for water absorption, clone 62 showed the best results, (3 to internal bond, only clone 58 didn`t attend specifications, (4 for the compression, clones 19.36 and 58 showed the best results, (5 for MOE and MOR, none of the clones presented values compatible to the bison process. It is suggested the continuation of this line of research, including the manipulation of variables of production, so that all properties be compatible to the minimum required standards.

  7. India's cement industry: Productivity, energy efficiency and carbon emissions

    Energy Technology Data Exchange (ETDEWEB)

    Schumacher, Katja; Sathaye, Jayant

    1999-07-01

    Historical estimates of productivity growth in India's cement sector vary from indicating an improvement to a decline in the sector's productivity. The variance may be traced to the time period of study, source of data for analysis, and type of indices and econometric specifications used for reporting productivity growth. Analysis shows that in the twenty year period, 1973 to 1993, productivity in the aluminum sector increased by 0.8% per annum. An econometric analysis reveals that technical progress in India's cement sector has been biased towards the use of energy and capital, while it has been material and labor saving. The increase in productivity was mainly driven by a period of progress between 1983 and 1991 following partial decontrol of the cement sector in 1982. The authors examine the current changes in structure and energy efficiency in the sector. Their analysis shows that the Indian cement sector is moving towards world-best technology, which will result in fewer carbon emissions and more efficient energy use. However, substantial further energy savings and carbon reduction potentials still exist.

  8. Biphasic products of dicalcium phosphate-rich cement with injectability and nondispersibility.

    Science.gov (United States)

    Ko, Chia-Ling; Chen, Jian-Chih; Hung, Chun-Cheng; Wang, Jen-Chyan; Tien, Yin-Chun; Chen, Wen-Cheng

    2014-06-01

    In this study, a calcium phosphate cement was developed using tetracalcium phosphate and surface-modified dicalcium phosphate anhydrous (DCPA). This developed injectable bone graft substitute can be molded to the shape of the bone cavity and set in situ through the piping system that has an adequate mechanical strength, non-dispersibility, and biocompatibility. The materials were based on the modified DCPA compositions of calcium phosphate cement (CPC), where the phase ratio of the surface-modified DCPA is higher than that of the conventional CPC for forming dicalcium phosphate (DCP)-rich cement. The composition and morphology of several calcium phosphate cement specimens during setting were analyzed via X-ray diffractometry and transmission electron microscopy coupled with an energy dispersive spectroscopy system. The compressive strength of DCP-rich CPCs was greater than 30MPa after 24h of immersion in vitro. The reaction of the CPCs produced steady final biphasic products of DCPs with apatite. The composites of calcium phosphate cements derived from tetracalcium phosphate mixed with surface-modified DCPA exhibited excellent mechanical properties, injectability, and interlocking forces between particles, and they also featured nondispersive behavior when immersed in a physiological solution.

  9. Comparison of Strength for Concrete with GGBS and Cement Using Accelerated Curing Method

    Directory of Open Access Journals (Sweden)

    K. Shyamala

    2016-10-01

    Full Text Available Ground granulated blast-furnace slag ( GGBS is the granular material formed iron ore is molted. blast furnace slag is by-product of steel manufacture which is sometimes used as a substitute for Portland cement. In steel industry when iron ore is molted, then in the molted state all the impurities come at its surface which are removed called slag. It consists mainly of the silicates and alumino silicates of calcium, which are formed in the blast furnace in molten form simultaneously with the metallic iron. Blast furnace slag is blended with Portland cement clinker to form portland blast furnace slag cement. GGBS is used to make durable concrete structures in combination with ordinary Portland cement and/or other pozzolanic materials. GGBFS has been widely used in Europe, and increasingly in the United States and in Asia (particularly in Japan and Singapore for its superiority in concrete durability, extending the lifespan of buildings from fifty years to a hundred years. This project presents the feasibility of the usage of GGBS as hundred percent substitutes for Ordinary portland cement in concrete. Design mix for M20 and M30 has been calculated using IS 10262-2009 for both accelrated curing in warm water and accelrated curing in boiling water method. Tests were conducted on cubes to study the strength of concrete by using GGBS and Ordinary portland cement

  10. 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.

  11. β-Dicalcium silicate-based cement: synthesis, characterization and in vitro bioactivity and biocompatibility studies.

    Science.gov (United States)

    Correa, Daniel; Almirall, Amisel; García-Carrodeguas, Raúl; dos Santos, Luis Alberto; De Aza, Antonio H; Parra, Juan; Delgado, José Ángel

    2014-10-01

    β-dicalcium silicate (β-Ca₂ SiO₄, β-C₂ S) is one of the main constituents in Portland cement clinker and many refractory materials, itself is a hydraulic cement that reacts with water or aqueous solution at room/body temperature to form a hydrated phase (C-S-H), which provides mechanical strength to the end product. In the present investigation, β-C₂ S was synthesized by sol-gel process and it was used as powder to cement preparation, named CSiC. In vitro bioactivity and biocompatibility studies were assessed by soaking the cement samples in simulated body fluid solutions and human osteoblast cell cultures for various time periods, respectively. The results showed that the sol-gel process is an available synthesis method in order to obtain a pure powder of β-C₂ S at relatively low temperatures without chemical stabilizers. A bone-like apatite layer covered the material surface after soaking in SBF and its compressive strength (CSiC cement) was comparable with that of the human trabecular bone. The extracts of this cement were not cytotoxic and the cell growth and relative cell viability were comparable to negative control.

  12. Characterization of composite materials based on cement-ceramic powder blended binder

    Science.gov (United States)

    Kulovaná, Tereza; Pavlík, Zbyšek

    2016-06-01

    Characterization of newly developed composite mortars with incorporated ceramic powder coming from precise brick cutting as partial Portland cement replacement up to 40 mass% is presented in the paper. Fine ceramic powder belongs to the pozzolanic materials. Utilization of pozzolanic materials is accompanied by lower request on energy needed for Portland clinker production which generally results in lower production costs of blended binder and lower CO2 emission. In this paper, the ceramic powder is used in cement based mortar composition in amount of 8, 16, 24, 32, and 40 mass% of cement. Chemical composition of ceramic powder is analyzed by X-Ray Fluorescence and X-Ray Diffraction. The particle size distribution of ceramics is accessed on laser diffraction principle. For 28 days cured mortar samples, basic physical and mechanical properties are experimentally determined. The obtained results demonstrate that ceramic powder has potential to replace a part of Portland cement in composition of cement based composites and to reduce negative environmental impact of their production.

  13. Effectiveness of the Top-Down Nanotechnology in the Production of Ultrafine Cement (~220 nm

    Directory of Open Access Journals (Sweden)

    Byung-Wan Jo

    2014-01-01

    Full Text Available The present investigation is dealing with the communition of the cement particle to the ultrafine level (~220 nm utilizing the bead milling process, which is considered as a top-down nanotechnology. During the grinding of the cement particle, the effect of various parameters such as grinding time (1–6 h and grinding agent (methanol and ethanol on the production of the ultrafine cement has also been investigated. Performance of newly produced ultrafine cement is elucidated by the chemical composition, particle size distribution, and SEM and XRD analyses. Based on the particle size distribution of the newly produced ultrafine cement, it was assessed that the size of the cement particle decreases efficiently with increase in grinding time. Additionally, it is optimized that the bead milling process is able to produce 90% of the cement particle <350 nm and 50% of the cement particle < 220 nm, respectively, after 6.3 h milling without affecting the chemical phases. Production of the ultrafine cement utilizing this method will promote the construction industries towards the development of smart and sustainable construction materials.

  14. 氧化镁对高镁熟料膨胀和强度影响研究进展%Effect of Magnesia on Expansion and Strength in High-magnesium Clinker:A Short Review

    Institute of Scientific and Technical Information of China (English)

    宋强; 张琼; 李婷

    2016-01-01

    The significance of high magnesium clinker production is discussed from the viewpoint of efficient utilization of limestone resources and advantage of compensation effect of high magnesium cement for concrete shrin-kage.Recent development on factors influencing periclase expansion,effects of raw material composition and burning condition on the content of periclase,and mineral content and strength development of high MgO clinker are reviewed. The existing problems are discussed,and the further research aspects are proposed.%从石灰石资源高效利用、高镁水泥补偿混凝土收缩方面阐述了高镁熟料生产的意义。针对高镁熟料中内含MgO,从方镁石膨胀影响因素、生料组成和煅烧制度对方镁石含量的影响,以及MgO对水泥熟料矿物相含量和强度的影响等方面,详细讨论了近年来国内外研究进展,对存在的有关问题进行了讨论,并提出了进一步研究建议。

  15. Synthesis of pure Portland cement phases

    DEFF Research Database (Denmark)

    Wesselsky, Andreas; Jensen, Ole Mejlhede

    2009-01-01

    Pure phases commonly found in Portland cement clinkers are often used to test cement hydration behaviour in simplified experimental conditions. The synthesis of these phases is covered in this paper, starting with a description of phase relations and possible polymorphs of the four main phases...... in Portland cement, i.e. tricalcium silicate, dicalcium silicate, tricalcium aluminate and tetracalcium alumino ferrite. Details of the The process of solid state synthesis are is described in general including practical advice on equipment and techniques. Finally In addition, some exemplary mix compositions...

  16. Utilization of Phosphogypsum and Low Grade Bauxite for Belite Rich Calcium Sulphoaluminate Cement%磷石膏与低品位矾土制备高贝利特-硫铝酸盐水泥

    Institute of Scientific and Technical Information of China (English)

    梁娇; 刘娜; 刘从振; 郭清春; 李昕成; 钱觉时

    2016-01-01

    利用磷石膏和低品位矾土制备高贝利特-硫铝酸盐水泥,研究了熟料的最佳煅烧工艺制度及配入过量磷石膏对水泥性能的影响。结果表明:在1300℃保温0.5 h,烧制出性能良好的高贝利特-硫铝酸盐水泥熟料,3 d和28 d水泥净浆抗压强度分别可达54.1 MPa和59.1 MPa;过量磷石膏形成的高温硬石膏能起到后掺石膏的作用,对水泥早期力学性能无不利影响。%Belite rich calcium sulphoaluminate cement was prepared with phosphogypsum and low grade bauxite. The optimum burning process for the clinker production and the excessive amount of phosphogypsum in the clinker on the performance of the cement were investigated. The results demonstrate that belite rich calcium sulphoaluminate cement with excellent performances can be achieved. The compressive strength of the cement paste at 3 d and 28 d reaches 54.1 MPa and 59.1 MPa, separately. The excessive amount of phosphgypsum in the clinker turns into anhydrate, serving the added gypsum and satisfying the hydration of C4A3S—. And the anhydrate does not harm the strength development of the cement paste.

  17. Silo semiesférico para clinker en Aboño, Asturias (España

    Directory of Open Access Journals (Sweden)

    Quintana Loche, Félix

    1972-09-01

    Full Text Available This semispherical silo for clinker storage was built by the construction firm Huarte and Co., in the cement factory at Abono, Asturias. Designed under the supervision of the Technical Services of Ciment Lafarge of Paris, by Enterprise René Marion and Structures Davidaff, it constitutes a world innovation among clinker storage systems. The great heterogeneity of the quarries required the study and use of new means of sampling and statistical dosification, thus producing cement of exceptional evenness. The semispherical storage silo is destined to contain a clinker stock of 35,000 tons; feed and collection are done by means of rotary systems that revolve around a ve/tical axis in the centre of the silo. This feature determined the shape of the silo — a spherical dome, 63.50 m in diameter, of which the centre is situated 5 m below the ground. The design adopted required the use of prefabrication, and is a world innovation in its function, form and building procedure.El silo semiesférico para almacenamiento de clinker ha sido construido por la Empresa Constructora Huarte y Cia., en la Fábrica de Cementos del Cantábrico de Abono (Asturias. El proyecto, elaborado bajo la supervisión de los Servicios Técnicos de Ciments Lafarge de París, y por la Entreprise René Marion y Structures Oavidaff, constituye una novedad mundial dentro de los sistemas de almacenamiento de clinker. La gran heterogeneidad de las canteras ha exigido el estudio y la utilización de nuevos medios de muestreo y dosificación estadística, permitiendo fabricar un cemento de una regularidad excepcional. El silo de almacenamiento semiesférico está destinado a contener un stock de clinker de 35.000 t; la alimentación y recogida se hacen por medio de sistemas rotativos que giran alrededor de un eje vertical que pasa por el centro del silo. Esta característica ha determinado naturalmente la forma del silo: una cúpula esférica, de 63,50 m de diámetro, cuyo centro se

  18. Preparation of magnesium phosphate cement by recycling the product of thermal transformation of asbestos containing wastes

    OpenAIRE

    2014-01-01

    Asbestos containing wastes have been employed for the first time in the formulation of magnesium phosphate cements. Two samples were mixed with magnesium carbonate and calcined at 1100 and 1300 C. Under these conditions, complete destruction of asbestos minerals is known to occur. The product, containing MgO, after reaction with water-soluble potassium di-hydrogen phosphate, led to the formation of hydrated phases at room temperature. Crystalline and amorphous reaction products were detected,...

  19. Reuse of de-inking sludge from wastepaper recycling in cement mortar products.

    Science.gov (United States)

    Yan, Shiqin; Sagoe-Crentsil, Kwesi; Shapiro, Gretta

    2011-08-01

    This paper presents results of an investigation into the use of de-inking sludge from a paper recycling mill as feedstock material in the manufacture of cement mortar products, including masonry blocks and mortar renders. Both physical and mechanical properties of mortar specimens containing various amounts of de-inking sludge were investigated. It was observed that the addition of de-inking sludge to cement mortar at a fixed water-to-cement ratio significantly reduced flow properties and increased setting time. Water absorption and volume of permeable voids of cement mortar increased with increased dosage of de-inking sludge, with a corresponding reduction of bulk density. The 91-day compressive strength of mortar samples with 2.5 wt% and 20 wt% de-inking sludge loadings retained 83% and 62% respectively of the reference mortar strength. The corresponding drying shrinkage increased by up to 160% compared to reference samples. However, a de-inking sludge loading of up to 2.5 wt% did not significantly alter measured physical and mechanical properties. The results demonstrate that despite the high moisture absorbance of de-inking sludge due to its organic matter and residual cellulose fibre content, it serves as a potential supplementary additive and its cellulosic content proving to be an active set retardant to cementitious masonry products.

  20. Use of Cement-Sand Admixture in Laterite Brick Production for Low Cost Housing

    Directory of Open Access Journals (Sweden)

    Isaac Olufemi AGBEDE

    2008-06-01

    Full Text Available Laterite was modified with 45% sand content by dry weight and stabilized with up to 9% cement content respectively and used in the production of 330 mm × 150 mm × 150 mm bricks through the application of a pressure of 3 N/mm2 with a brick moulding machine. Results showed that laterite used in this study cannot be stabilized for brick production within the economic cement content of 5% specified for use in Nigeria. However, bricks made with laterite admixed with 45% sand and 5% cement attained a compressive strength of 1.80 N/mm2 which is greater than the specified minimum strength value of 1.65 N/mm2. Cost comparison of available walling materials in Makurdi metropolis showed that the use of bricks made from 45% sand and 5% cement resulted in a saving of 30 - 47% when compared with the use of sandcrete blocks while the use of fired clay bricks resulted in a savings of 19% per square meter of wall. The study therefore recommends the use of laterite bricks in Makurdi and other locations because it is more economical and environmental friendly than fired clay bricks.

  1. Use of secondary fuels in rotary kilns of the cement industry; Einsatz von Sekundaerstoffen in Drehofenanlagen der Zementindustrie

    Energy Technology Data Exchange (ETDEWEB)

    Hoenig, V. [Forschungsinstitut der Zementindustrie, Duesseldorf (Germany)

    1998-09-01

    Most cement works in Germany use secondary materials for cement production or are planning to do so. Many of the materials in question, such as used tyres, have been recycled in an environmentally acceptable way for decades, and a large body of experience has accumulated on their use in the cement industry. In the cement industry secondary materials are understood to comprise secondary fuels as well as secondary raw materials. The latter have for some part replaced the natural raw materials used for burning cement clinker, the preliminary product of cement. By using used tyres, used oil and other waste materials as secondary fuels the cement industry has for decades contributed to an environmentally acceptable form of waste disposal. The use of secondary materials has also enabled the cement industry to improve its economic situation. In response to the enactment of the Materials Recycling Law the cement industry has during the past few years turned its attention to the utilisation of other waste materials. The criteria relevant to the cement industry`s choice of a waste material as secondary material lastly depends on the process-related side constraints attending the clinker burning process and the requirements on the burning process with regard to product quality and environmental acceptability. [Deutsch] Die meisten Zementwerke in Deutschland setzen bei der Zementherstellung Sekundaerstoffe ein oder planen ihren Einsatz. Fuer einige dieser Stoffe, wie z.B. Altreifen gilt, dass sie bereits seit Jahrzehnten umweltvertraeglich verwertet werden, so dass viele Erfahrungen ueber deren Einsatz in der Zementindustrie vorliegen. Unter Sekundaerstoffen werden in der Zementindustrie sowohl Sekundaerbrennstoffe wie auch Sekundaerrohstoffe verstanden. Letztere ersetzen teilweise die natuerlichen Rohstoffe, aus denen der Zementklinker, das Vorprodukt des Zements, gebrannt wird. Bezueglich der Sekundaerbrennstoffe traegt die Zementindustrie schon seit Jahrzehnten zu einer

  2. Study on witherite as admixture of cement%毒重石作水泥混合材的研究

    Institute of Scientific and Technical Information of China (English)

    刘煦; 吕淑珍; 霍冀川

    2012-01-01

    结合毒重石质量优、易加工、生产成本低及吸收X射线、γ射线等特点,制备了以普通硅酸盐水泥熟料为主要原料,毒重石作水泥混合材,辅以适量石膏的水硬性胶凝材料.考察了毒重石掺量对水泥标准稠度用水量、凝结时间、安定性、不同龄期机械强度以及辐射屏蔽能力的影响.结果表明:毒重石对普通硅酸盐水泥熟料具有一定的缓凝作用;毒重石本身参与水化的能力很差,在水泥中基本上是作为非活性掺和材料,主要起填料的作用;毒重石水泥具有一定的辐射屏蔽能力,且随着毒重石掺量的增加,水泥的屏蔽效果增强.%Combining witherite's characteristics,such as high quality,easy-processing,low production cost,absorbing X ray and y ray etc.,hydraulic cementing material was prepared by using ordinary portland cement clinker as main material, witherite as admixture,and proper amount of gypsum as excipients.Influences of different witherite doping contents on water requirement of normal consistency, setting time, soundness, mechanical strength, and radiation shield performance of the cement were investigated.Results showed that witherite had some retarding effect on the Portland cement clinker.However.the ability of witherite to participate in hydration of cement clinker was so poor that it was basically being an inactive admixture and played a role of filler in cement.Cement based materials with witherite as admixture had certain radiation shield ability, and the radiation shielding effect was more apparent as the content of witherite increased.

  3. The influence of cement type and temperature on chloride binding in cement paste

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede; Korzen, Migge Sofie Hoffmann; Skibsted, Jørgen

    1998-01-01

    This paper describes effects of cement type and temperature on chloride binding in cement paste, which is an important subject in relation to life-time modelling of reinforced concrete structures. The influence of cement type on chloride binding is investigated by substituting cement with pure...... cement clinker. Both theoretical considerations and experimental data for chloride binding in cement pastes are presented. A physico-chemically based model to describe the influence of temperature on physical binding of chloride is presented. Solid-state 27Al and 29Si magic-angle spinning (MAS) nuclear...... magnetic resonance (NMR) spectroscopy has been used for quantification of the anhydrous and hydrated aluminate and silicate phases in the chloride exposed cement pastes. The 27Al isotropic chemical shift and nuclear quadrupole coupling is reported for a synthetic sample of Friedel's salt, Ca2Al(OH)6Cl×2H2O....

  4. CEMENT SLURRIES FOR GEOTHERMAL WELLS CEMENTING

    Directory of Open Access Journals (Sweden)

    Nediljka Gaurina-Međimurec

    1994-12-01

    Full Text Available During a well cementing special place belongs to the cement slurry design. To ensure the best quality of cementing, a thorough understanding of well parameters is essential, as well as behaviour of cement slurry (especially at high temperatures and application of proven cementing techniques. Many cement jobs fail because of bad job planning. Well cementing without regarding what should be accomplished, can lead to well problems (channels in the cement, unwanted water, gas or fluid production, pipe corrosion and expensive well repairs. Cementing temperature conditions are important because bot-tomhole circulating temperatures affect slurry thickening time, arheology, set time and compressive strength development. Knowing the actual temperature which cement encounters during placement allows the selection of proper cementing materials for a specific application. Slurry design is affected by well depth, bottom hole circulating temperature and static temperature, type or drilling fluid, slurry density, pumping time, quality of mix water, fluid loss control, flow regime, settling and free water, quality of cement, dry or liquid additives, strength development, and quality of the lab cement testing and equipment. Most Portland cements and Class J cement have shown suitable performances in geot-hermal wells. Cement system designs for geothermal wells differ from those for conventional high temperature oil and gas wells in the exclusive use of silica flour instead of silica sand, and the avoidance of fly ash as an extender. In this paper, Portland cement behaviour at high temperatures is described. Cement slurry and set cement properties are also described. Published in literature, the composition of cement slurries which were tested in geothermal conditions and which obtained required compressive strength and water permeability are listed. As a case of our practice geothermal wells Velika Ciglena-1 and Velika Ciglena-la are described.

  5. Effect of AlF3 Production Waste on the Properties of Hardened Cement Paste

    Directory of Open Access Journals (Sweden)

    Danutė VAIČIUKYNIENĖ

    2012-06-01

    Full Text Available The possibility to use by-product SiO2·nH2O (often called AlF3 production waste in cement casting has been attracting the interest of researchers for many years, although high content of fluorine makes the use of amorphous SiO2 problematic. Finding the way of utilizing waste products is a very important research topic at the moment. In this study AlF3 production waste was investigated as the basic ingredient of a new pozzolanic material. The goal of this study is to investigate the possibilities of using AlF3 production waste, washed in ammonia solution, in cement stone specimens. Chemically treated silica gel additive was proved to reduce the amount of Ca(OH2 and CaCO3 in hardened cement paste samples. Experimental research has revealed that the density in hydrated samples reduces from 2220 kg/m3 to 2030 kg/m3 with the increase of silica gel content from 0 % to 35 %. The compressive strength of samples containing 10 % of silica gel additive increased by 8.04 % compared to the samples without the additive. SiO2 additive used at 10 % and 20 % increased the maximum hydration temperature. In this case, the additive modifies the hydration kinetics.DOI: http://dx.doi.org/10.5755/j01.ms.18.2.1925

  6. Étude du système clinker sulfoalumineux - gypse : stabilité et durabilité des hydrates

    OpenAIRE

    DESBOIS, Tiffany

    2009-01-01

    Le clinker sulfoalumineux est l'un des ciments prometteurs dans la recherche de la diminution des gaz à effet de serre issus de la production du ciment. Ce clinker produit des ciments présentant des résistances en compression importantes et, dans certains cas, une forte expansion conduisant parfois à de la fissuration. Notre projet de recherche porte sur la détermination du domaine de stabilité de ces matériaux ainsi que sur la compréhension des mécanismes physico-chimiques associés à l...

  7. Groundnut shell ash as a partial replacement of cement in sandcrete blocks production

    Directory of Open Access Journals (Sweden)

    H. Mahmoud

    2012-12-01

    Full Text Available The production of sandcrete blocks using groundnut shell ash (GSA as cement replacement was investigated. Six number sandcrete blocks were cast for each replacement levels (0, 10,20,30,40, and 50 percentage with GSA. The blocks were cured and crushed at 7, 14, 21, and 28 days. The results show that the compressive strength ranges from 4.50 N/mm2 to 0.26N/mm2.The optimum replacement level was achieved at 20% with a corresponding strength of 3.58 N/mm2. The strength at the optimum level was within the recommended limit of the Nigerian Industrial Standard (NIS 87:2000. The results also showed that the strength decreases with increase of cement above 20% replacement. It was also observed that in the chemical composition of the GSA as compared to cement, the amount of K2O was higher in GSA and also CaO was less than what is obtained in cement.

  8. Effect of SO3 on Modification of C3S and Property in High Magnesium Content Clinker%SO3掺杂对高镁熟料Alite晶型和水化性能的影响

    Institute of Scientific and Technical Information of China (English)

    李晓冬; 沈裕盛; 黎学润; 周妍; 沈晓冬

    2013-01-01

    文章探讨了SO3对高镁水泥熟料中C3S晶型的调控以及对该熟料水化性能的影响。通过X射线衍射对熟料矿物含量和C3S的晶型进行表征并测试了熟料的净浆强度及结合水。研究表明:当SO3的掺量为1%、2%时不会对C3S的形成带来阻碍,样品中f-CaO含量均小于1%。在该熟料中,阿利特以M3型为主,多为细小的晶体,SO3的掺入能够稳定M1型的阿利特。1%~2%SO3的掺入能促进熟料的水化,提高熟料的中后期强度,当掺量为2%时3、28 d净浆抗压强度分别提高8%和5%。水化程度随着SO3掺量的增加而增加,水化产物中含有大量的钙钒石。%Modification of C3S and impact properties of cement clinker by addition of SO3 into high MgO content were investigated. Modification of C3S in clinker was characterized with XRD. Paste compressive strength and combined water were measured. Results showed: 1% and 2% addition of SO3 had no negative impact on the formation of C3S with the evidence of low f-CaO content in clinker;addition of SO3 could improve the later strength of clinker. The paste compressive strength in 3 and 28 d were separately im-proved by 8%and 5%with 2%addition of SO3. The degree of hydration was enhanced by increasing the SO3 addition with high et-tringite content hydration products.

  9. 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.

  10. Alite-ye'elimite cement: Synthesis and mineralogical analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Suhua [State Key Laboratory of Materials-Oriented Chemical Engineering, College of Materials Science and Engineering, Nanjing University of Technology, Nanjing 210009 (China); Snellings, Ruben [Laboratory of Construction Materials, Institute of Materials, Ecole Polytechnique Fédéral de Lausanne, Station 12, CH-1015 Ecublens (Switzerland); Li, Xuerun [State Key Laboratory of Materials-Oriented Chemical Engineering, College of Materials Science and Engineering, Nanjing University of Technology, Nanjing 210009 (China); Shen, Xiaodong, E-mail: xdshen@njut.edu.cn [State Key Laboratory of Materials-Oriented Chemical Engineering, College of Materials Science and Engineering, Nanjing University of Technology, Nanjing 210009 (China); Scrivener, Karen L. [Laboratory of Construction Materials, Institute of Materials, Ecole Polytechnique Fédéral de Lausanne, Station 12, CH-1015 Ecublens (Switzerland)

    2013-03-15

    Alite-ye'elimite cement is an alternative cement that combines desirable characteristics of calcium sulfoaluminate cements and Portland cement in that it shows improved strength development at early age while retaining high portlandite contents. The key problem in the clinkering process is to produce the alite-ye'elimite phase assemblage so that both phases can co-exist. In this study, a new synthesis method is proposed to achieve the coexistence of alite and ye'elimite consisting of a secondary heat treatment step at 1250 °C after regular Portland clinker firing at 1450 °C. Quantitative X-ray powder diffraction and electron microscopy were used to analyze the phase composition of clinker before and after the secondary heat treatment. The results show that ye'elimite develops during secondary heat treatment of calcium sulphate enriched clinker by reaction of C{sub 3}A and sulphate phases. Additional ferrite is formed as result of rejection of Fe originally in solid solution with C{sub 3}A during ye'elimite formation.

  11. Phase I: energy-conservation potential of Portland cement particle-size-distribution control. Final report, March 1979

    Energy Technology Data Exchange (ETDEWEB)

    1979-03-01

    The properties of cements with carefully controlled particle-size distributions were compared with those of normally ground cements having a Blaine fineness of about 3600 cm/sup 2//g. Progressive reduction of the maximum particle size to 20 microns improved strength development. Further reduction to about 14 microns decreased rather than improved strength development. Some of these particle-size-controlled cements produce as-high, and often much-higher, strengths at ages from 1 to 60 days at Blaine finenesses 450 to 800 cm/sup 2//g lower than the normal grinds of the same composition. The cements with 20-micron maximum-size particles can have finenesses as low as 2800 cm/sup 2//g, whereas with larger particles, higher specific-surface areas are required for equal strengths. The improved strengths were a result of more-rapid and more-complete hydration of the cement. Variations of clinker composition did not significantly alter these conclusions. Drying shrinkage of the particle-size-controlled cements was in some cases less than for normally ground cements. They also performed better than normally ground cements over a wide range of mixing and curing temperature (42/sup 0/F to 100/sup 0/F). Direct energy conservation of 27% in finish grinding and 8.5% in more-efficient utilization of the cement is estimated to result from the use of particle-size-controlled cements. For a US production of 75 million tons, this corresponds to conservation of 46.5 trillion Btu/year.

  12. Study on methods of calculating resistance of flue gas from cement production line into dual-pressure waste heat recovery power generation system%水泥线双压余热发电系统烟风阻力计算方法研究

    Institute of Scientific and Technical Information of China (English)

    王为术; 贺慧宁; 董英斌; 张红生; 刘军

    2011-01-01

    The dual-pressure waste heat recovery power generation system efficiently recovers low-temperatured waste heat from cement production lines. In order to accurately calculate the pressure of flue gas from cement production lines into the waste heat recovery power generation system, three resistance mathematical models are deduced based on the momentum law and the energy conservation law, which are cooling resistance in clinker layers, resistance of flue gas flowing from boilers into pipeline as well as resistance in boiler tubes. In addition, visual software of calculating resistance of flue gas is developed based on C++ Builder.%水泥线双压余热发电系统可高效回收水泥线低温余热,为准确计算水泥线余热发电系统的烟风阻力,基于动量定律和能量守恒定律,推导建立了熟料料层冷却阻力、锅炉引入管道阻力、锅炉管束阻力等阻力计算模型,并基于C++Builder开发了水泥线余热发电系统烟风阻力可视化计算软件.

  13. Severe particulate pollution from the deposition practices of the primary materials of a cement plant.

    Science.gov (United States)

    Kourtidis, K; Rapsomanikis, S; Zerefos, C; Georgoulias, A K; Pavlidou, E

    2014-01-01

    Global cement production has increased twofold during the last decade. This increase has been accompanied by the installation of many new plants, especially in Southeast Asia. Although various aspects of pollution related to cement production have been reported, the impact of primary material deposition practices on ambient air quality has not yet been studied. In this study, we show that deposition practices can have a very serious impact on levels of ambient aerosols, far larger than other cement production-related impacts. Analyses of ambient particulates sampled near a cement plant show 1.3-30.4 mg/m(3) total suspended particulates in the air and concentrations of particles with a diameter of 10 μm or less at 0.04-3 mg/m(3). These concentrations are very high and seriously exceed air quality standards. We unequivocally attribute these levels to outdoor deposition of cement primary materials, especially clinker, using scanning electron microscopy/energy-dispersive X-ray spectroscopy. We also used satellite-derived aerosol optical depth maps over the area of study to estimate the extent of the spatial impact. The satellite data indicate a 33% decrease in aerosol optical depth during a 10-year period, possibly due to changing primary material deposition practices. Although the in situ sampling was performed in one location, primary materials used in cement production are common in all parts of the world and have not changed significantly over the last decades. Hence, the results reported here demonstrate the dominant impact of deposition practices on aerosol levels near cement plants.

  14. Pulverized coal and substitute fuels for the cement manufacturing industry

    Energy Technology Data Exchange (ETDEWEB)

    Dobrowsky, F.

    1981-01-01

    This paper comprises an article of general technical interest on coal and its use in the cement industry, plus the scope for using substitute fuels. Discusses coal properties and preparation (crushing). Describes the heating systems of the cement ovens: burners, combustion and parameters governing flame-length. Looks at operation problems connected with heating of the coal: caking, fusing, clinker quality and behaviour of the refractory bricks. Also discusses substitute fuels: type of fuel, scope for utilisation and requisite precautions. 32 refs.

  15. Mossbauer Effect Study of the Hyper fine Structure of the Different Phases of Iron in the Portland Cement Produced in Qatar

    OpenAIRE

    Eissa, N. A. [نبيل عيسى; Sallam, H. A.; Al-Houty, L.; Al-Mauraikhy, M.

    1981-01-01

    Various samples of the raw materials used in the manufacture of Portland cement in Qatar, the clinker produced and the cement itself were studied by using Mossbauer Effect and X-ray diffraction analysis in order to investigate the hyperfine structure of the iron forms present and the distribution of these forms among the different phases of the cement. The results obtained revealed the presence of five forms of iron in the cement clinker (a) Fe3"1" ions in octahedral sites existed in the ferr...

  16. DEVELOPING A NEW GENERATION OF HIGH PERFORMANCE COMPOSITE CEMENT

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper proposed a new generation of high performance composite cement which is designed according to the optimization of composition and structure of cement paste and is manufactured by blending the different components with special composite techniques. Each of these components has its different special property, and should be compatible with each other and match each other, and the properties of them are complementary mutually. At present, such kind of high performance composite cement can be manufactured with high reactivity cement clinker, ground granulated blast-furnace slag, high grade fly ash, silica fume etc.

  17. Evaluation of leaching behavior and immobilization of zinc in cement-based solidified products

    Directory of Open Access Journals (Sweden)

    Krolo Petar

    2012-01-01

    Full Text Available This study has examined leaching behavior of monolithic stabilized/solidified products contaminated with zinc by performing modified dynamic leaching test. The effectiveness of cement-based stabilization/solidification treatment was evaluated by determining the cumulative release of Zn and diffusion coefficients, De. The experimental results indicated that the cumulative release of Zn decreases as the addition of binder increases. The values of the Zn diffusion coefficients for all samples ranged from 1.210-8 to 1.1610-12 cm2 s-1. The samples with higher amounts of binder had lower De values. The test results showed that cement-based stabilization/solidification treatment was effective in immobilization of electroplating sludge and waste zeolite. A model developed by de Groot and van der Sloot was used to clarify the controlling mechanisms. The controlling leaching mechanism was found to be diffusion for samples with small amounts of waste material, and dissolution for higher waste contents.

  18. Production of cements from Illinois coal ash. Final technical report, September 1, 1995--August 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, J.C.; Bhatty, J.L.; Mishulovich, A.

    1997-05-01

    The objective of this program is to convert Illinois coal combustion residues, such as fly ash, bottom ash, and boiler slag, into novel cementitious materials for use in the construction industry. These residues are composed largely of SiO{sub 2}, Al{sub 2}O{sub 3}, Fe{sub 2}O{sub 3}, MgO, and CaO, which are also the major components of cement. Since the residues are used as an integral component of the cement and not just as additives to concrete, larger amounts of the residues can be utilized. The process uses submerged combustion to melt blends of coal combustion residues with lime, clay, and/or sand. The submerged combustion melter utilizes natural gas-oxidant firing directly into a molten bath to provide efficient melting of mineral-like materials. Use of this melter for cement production has many advantages over rotary kilns including very little, if any, grinding of the feed material, very low emissions, and compact size. During the first year of the program, samples of coal combustion residues were blended and mixed, as needed; with lime, clay, and/or sand to adjust the composition. Six mixtures, three with fly ash and three with bottom ash, were melted in a laboratory-scale furnace. The resultant products were used in mortar cubes and bars which were subjected to ASTM standard tests of cementitious properties. In the hydraulic activity test, mortar cubes were found to have a strength comparable to standard mortar cements. In the compressive strength test, mortar cubes were found to have strengths that exceeded ASTM blended cement performance specifications. In the ASR expansion test, mortar bars were subjected to alkali-silica reaction-induced expansion, which is a problem for siliceous aggregate-based concretes that are exposed to moisture. The mortar bars made with the products inhibited 85 to 97% of this expansion. These results show that residue-based products have an excellent potential as ASR-preventing additions in concretes.

  19. Impact of kiln thermal energy demand and false air on cement kiln flue gas CO2 capture

    Energy Technology Data Exchange (ETDEWEB)

    Arachchige, Udara S.P.R.; Kawan, Dinesh; Tokheim, Lars-Andre [Telemark University College, Porsgrunn (Norway); Melaaen, Morten C. [Telemark University College, Porsgrunn (Norway); (Tel-Tek, Porsgrunn (Norway)

    2013-07-01

    The present study is focused on the effect of the specific thermal energy demand and the false air factor on carbon capture applied to cement kiln exhaust gases. The carbon capture process model was developed and implemented in Aspen Plus. The model was developed for flue gases from a typical cement clinker manufacturing plant. The specific thermal energy demand as well as the false air factor of the kiln system were varied in order to determine the effect on CO2 capture plant performance, such as the solvent regeneration energy demand. In general, an increase in the mentioned kiln system factors increases the regeneration energy demand. The reboiler energy demand is calculated as 3270, 3428 and 3589 kJ/kg clinker for a specific thermal energy of 3000, 3400 and 3800 kJ/kg clinker, respectively. Setting the false air factor to 25, 50 or 70% gives a reboiler energy demand of 3428, 3476, 3568 kJ/kg clinker, respectively.

  20. Low SO2 Emission Preheaters for Cement Production

    DEFF Research Database (Denmark)

    Rasmussen, Martin Hagsted

    in this thesis has been to produce CaO with a large surface area in order to increase the absorption of SO2. For this purpose flash calcination of CaCO3, calcination under vacuum, calcination in a fixed bed and a fluid bed has been tested between 650 °C and 850 °C. The results showed that flash calcination...... reaction between SO2 and CaO is so fast that the observed rates exclusively are determined by solid state diffusion in the product layer of the non-porous CaO grains. An activation energy of 115 kJ/mole was found to fit all CaO sources very well, even though data fitting by the least sum of squares method...

  1. Heuristic economic assessment of the Afghanistan construction materials sector: cement and dimension stone production

    Science.gov (United States)

    Mossotti, Victor G.

    2014-01-01

    Over the past decade, the U.S. Government has invested more than $106 billion for physical, societal, and governmental reconstruction assistance to Afghanistan (Special Inspector General for Afghanistan Reconstruction, 2012a). This funding, along with private investment, has stimulated a growing demand for particular industrial minerals and construction materials. In support of this effort, the U.S. Geological Survey released a preliminary mineral assessment in 2007 on selected Afghan nonfuel minerals (Peters and others, 2007). More recently, the 2007 mineral assessment was updated with the inclusion of a more extensive array of Afghan nonfuel minerals (Peters and others, 2011). As a follow-up on the 2011 assessment, this report provides an analysis of the current use and prospects of the following Afghan industrial minerals required to manufacture construction materials: clays of various types, bauxite, gypsum, cement-grade limestone, aggregate (sand and gravel), and dimension stone (sandstone, quartzite, granite, slate, limestone, travertine, marble). The intention of this paper is to assess the: Use of Afghan industrial minerals to manufacture construction materials, Prospects for growth in domestic construction materials production sectors, Factors controlling the competitiveness of domestic production relative to foreign imports of construction materials, and Feasibility of using natural gas as the prime source of thermal energy and for generating electrical energy for cement production. The discussion here is based on classical principles of supply and demand. Imbedded in these principles is an understanding that the attributes of supply and demand are highly variable. For construction materials, demand for a given product may depend on seasons of the year, location of construction sites, product delivery time, political factors, governmental regulations, cultural issues, price, and how essential a given product might be to the buyer. Moreover, failure on the

  2. The Application of SCC-DV-Xα Computational Method of Quantum Chemistry in Cement Chemistry

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    It has been explored why quantum chemistry is applied to the research field of cement chemistry. The fundamental theory of SCC-DV-Xα computational method of quantum chemistry is synopsized. The results obtained by computational quantum chemistry method in recent years of valence-bond structures and hydration activity of some cement clinker minerals, mechanical strength and stabilization of some hydrates are summarized and evaluated. Finally the prospects of the future application of quantum chemistry to cement chemistry are depicted.

  3. En route to a multi-model scheme for clinker comminution with chemical grinding aids

    CERN Document Server

    Mishra, R K; Carmona, H A; Wittel, F K; Sawley, M L; Weibel, M; Gallucci, E; Herrmann, H J; Heinz, H; Flatt, R J

    2015-01-01

    We present a multi-model simulation approach, targeted at understanding the behavior of comminution and the effect of grinding aids (GAs) in industrial cement mills. On the atomistic scale we use Molecular Dynamics (MD) simulations with validated force field models to quantify elastic and structural properties, cleavage energies as well as the organic interactions with mineral surfaces. Simulations based on the Discrete Element Method (DEM) are used to integrate the information gained from MD simulations into the clinker particle behavior at larger scales. Computed impact energy distributions from DEM mill simulations can serve as a link between large-scale industrial and laboratory sized mills. They also provide the required input for particle impact fragmentation models. Such a multi-scale, multi-model methodology paves the way for a structured approach to the design of chemical additives aimed at improving mill performance.

  4. Emerging Energy-efficiency and CO{sub 2} Emission-reduction Technologies for Cement and Concrete Production

    Energy Technology Data Exchange (ETDEWEB)

    Hasanbeigi, Ali; Price, Lynn; Lin, Elina

    2012-04-06

    Globally, the cement industry accounts for approximately 5 percent of current anthropogenic carbon dioxide (CO{sub 2}) emissions. World cement demand and production are increasing significantly, leading to an increase in this industry's absolute energy use and CO{sub 2} emissions. Development of new energy-efficiency and CO{sub 2} emission-reduction technologies and their deployment in the market will be key for the cement industry's mid- and long-term climate change mitigation strategies. This report is an initial effort to compile available information on process description, energy savings, environmental and other benefits, costs, commercialization status, and references for emerging technologies to reduce the cement industry's energy use and CO{sub 2} emissions. Although studies from around the world identify a variety of sector-specific and cross-cutting energy-efficiency technologies for the cement industry that have already been commercialized, information is scarce and/or scattered regarding emerging or advanced energy-efficiency and low-carbon technologies that are not yet commercialized. This report consolidates available information on nineteen emerging technologies for the cement industry, with the goal of providing engineers, researchers, investors, cement companies, policy makers, and other interested parties with easy access to a well-structured database of information on these technologies.

  5. Use of waste gypsum to replace natural gypsum as set retarders in portland cement.

    Science.gov (United States)

    Chandara, Chea; Azizli, Khairun Azizi Mohd; Ahmad, Zainal Arifin; Sakai, Etsuo

    2009-05-01

    The present study is focused on clarifying the influence of waste gypsum (WG) in replacing natural gypsum (NG) in the production of ordinary Portland cement (OPC). WG taken from slip casting moulds in a ceramic factory was formed from the hydration of plaster of paris. Clinker and 3-5wt% of WG was ground in a laboratory ball mill to produce cement waste gypsum (CMWG). The same procedure was repeated with NG to substitute WG to prepare cement natural gypsum (CMNG). The properties of NG and WG were investigated via X-ray Diffraction (XRD), X-ray fluorescence (XRF) and differential scanning calorimetry (DSC)/thermogravimetric (TG) to evaluate the properties of CMNG and CMWG. The mechanical properties of cement were tested in terms of setting time, flexural and compressive strength. The XRD result of NG revealed the presence of dihydrate while WG contained dihydrate and hemihydrate. The content of dihydrate and hemihydrates were obtained via DSC/TG, and the results showed that WG and NG contained 12.45% and 1.61% of hemihydrate, respectively. Furthermore, CMWG was found to set faster than CMNG, an average of 15.29% and 13.67% faster for the initial and final setting times, respectively. This was due to the presence of hemihydrate in WG. However, the values obtained for flexural and compressive strength were relatively the same for CMNG and CMWG. Therefore, this result provides evidence that WG can be used as an alternative material to NG in the production of OPC.

  6. Reuse of By-Products from Ready-Mixed Concrete Plants for the Production of Cement Mortars

    Directory of Open Access Journals (Sweden)

    Monika Zervaki

    2013-06-01

    Full Text Available This study was motivated by the necessity to recycle sludge water resulting from washing out concrete mixing trucks - a problem of both environmental and economic importance for the ready-mixed concrete industry. Sludge water from ready-mixed concrete plants as well as dry sludge, which is derived from the settling of the water, are hazardous for disposal due to their high pH value (pH>11.5. In this work, cement mortars were composed using either sludge water after various treatment, or dry sludge in several ratios. The cement mortars were tested for their workability and strength development. The purpose of this experimental design was to prove that sludge water, as well as sludge in a wet or dry form, can be used in the production of mortars without degrading any of their properties.

  7. 高原环境3500t/d熟料线100%燃无烟煤生产的系统设计%Design of 3500t/d clinker production line burning anthracite only

    Institute of Scientific and Technical Information of China (English)

    顾金土

    2013-01-01

      在1420 m海拔的贵州毕节江天水泥100%燃无烟煤工程设计中,对当地产无烟煤取样进行了燃烧特性研究分析,确定窑用无烟煤细度(R0.08mm)控制≤3%,分解炉用无烟煤细度(R0.08mm)控制≤2%。并重点对分解炉的形式与结构进行调整,控制分解炉系统煤粉停留时间约31.84 s;同时采用专用四通道窑头燃烧器、高效篦冷机和大窑门罩等措施,确保煤粉在窑炉内的快速完全燃烧。投产后,该生产线系统稳定,实现了优质高产运行。%  In design of Guizhou Bijie Jiangtian Cement burning anthracite project at the altitude of 1 420 m, combustion characteristic of local anthracite samples was studied, and the fineness of anthracite for kiln should be controlled at R0.08mm≤3%,and for precalciner at R0.08mm≤2%. The shape and structure of precalciner was adjusted to control residence time of coal powder about 31.84s. Measures as ap⁃plying special four-tunnel burner, high efficiency grate cooler and large kiln hood were adopted to ensure quick and complete combus⁃tion of coal powder. Since the production line was put into production,the whole system has been stable, realizing high quality and out⁃put.

  8. Utilization of CO2 in High Performance Building and Infrastructure Products

    Energy Technology Data Exchange (ETDEWEB)

    DeCristofaro, Nicholas [Solidia Technologies Inc., Piscataway, NJ (United States)

    2015-11-01

    -core slabs, and aerated concrete were produced to verify the utility of the CO2-curing process. These products exhibited a range of part dimensions and densities that were representative of the precast concrete industry. In the subsequent Demonstration of Commercial Development phase, the characteristics and performance of Solidia Cement made at a LafargeHolcim cement plant were established. This Solidia Cement was then used to demonstrate the CO2-curing process within operating concrete plants. Pavers, concrete masonry units and roofing tiles were produced according to ASTM and manufacturer specifications. A number of attractive manufacturing economies were recognized when Solidia Cement-based concrete parts were compared to their Portland cement based counterparts. These include reduced raw materials waste, reduced dependence on admixtures to control efflorescence, shorter curing time to full concrete strength, faster equipment clean-up, reduced equipment maintenance, and improved inventory management. These economies make the adoption of the Solidia Cement / CO2-curing process attractive even in the absence of environmental incentives. The culminating activity of the Demonstration of Commercial Development phase was the conversion of 10% of the manufacturing capacity at a concrete paver and block company from Portland cement-based products to Solidia Cement-based products. The successful completion of the Demonstration of Commercial Development phase clearly illustrated the environmental benefits associated with Solidia Cement and Solidia Concrete technologies. The industrial production of Solidia Cement, as a low-lime alternative to traditional Portland cement, reduces CO2 emissions at the cement kiln from 816 kg of CO2 per tonne of Portland cement clinker to 570 kg per tonne of Solidia Cement clinker. Industrial scale CO2-curing of Solidia Concrete sequestered a net of 183 kg of CO2 per tonne of Solidia Cement used in concrete pavers. Taken together, these two effects

  9. German Cement Industry's voluntary efforts on the issue of climate change : a success story

    Energy Technology Data Exchange (ETDEWEB)

    Hoenig, V.; Schneider, M. [German Cement Industry (Germany)

    2001-07-01

    In 1995, the cement industry in Germany stated that it would reduce energy consumption by 20 per cent between 1987 and 2005. In 2000, this commitment was adapted to international agreements such as the Kyoto Protocol. The voluntary agreement now includes a reduction of the specific energy-related carbon dioxide emissions from 1990 to 2008/12 by 28 per cent. Burning and grinding facilities have been optimized in recent years and the cement industry in Germany is planning to increase the use of fossil fuels by using waste products and by promoting the marketing of blended cements. The energy related carbon dioxide emissions were reduced by 3.6 million tonnes per year from 1987 to 1999 in the German cement industry as a result of these efforts. The use of waste products has also been increased from 4 to 23 per cent during this same time period and the clinker portion in cement has been decreased from 86 to 80.6 per cent. Granulated blast-furnace slag and unburned limestone has become the main constituent in cement. This paper also discussed the extent to which other instruments such as emissions trading, joint implementation and the clean development mechanism will have on the future of the cement industry. This paper was divided into several sections entitled: (1) voluntary agreement on climate change, (2) improvement in manufacturing processes, (3) optimization of existing kilns, (4) waste heat recovery, (5) reduction of electric power consumption, (6) remaining energy reduction potentials, (7) promotion of blended cement consumption, (8) market development, (9) use of secondary fuels, (10) greenhouse gas emissions, (11) energy related carbon dioxide emissions, (12) carbon dioxide emissions from the calcination of limestone, and (13) other greenhouse gas emissions. 3 tabs., 9 figs.

  10. Effect of Additives on the Morphology of the Hydrated Product and Physical Properties of a Calcium Phosphate Cement

    Institute of Scientific and Technical Information of China (English)

    Xiupeng WANG; Jiandong YE; Yingjun WANG

    2008-01-01

    The morphology of a hydrated calcium phosphate cement (CPC) doped with several normally used additives was investigated by scanning electron microscopy (SEM) and the compressive strength of the cement was determined in this study. The hydrated products of CPC without additives was rod-like hydroxyapatite (HA) grains with around 2-5 μm in length and 100 nm in width. The addition of Sr obviously decreased the crystal size of the rod-like grains. CPCs containing carbonate, collagen and gelatin showed flake-like crystal morphology. Crylic acid-containing CPC presented flocculus-like structure. And malic acid-containing CPC exhibited oriented flake-like structure. The X-ray diffraction (XRD) analysis showed that the additives used in this study did not alter the hydration products of the cement. The compressive strength tests indicated that the compressive strength of the cement with rod-like morphology HA crystals was much higher than that of the cement with flake-like morphology HA crystals, and the cement with oriented flake-like morphology HA crystals .exhibited the poorest compressive strength.

  11. Pollution and Prevention of Pb during Cement Calcination

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Emission pollution and prevention measures of Pb during cement calcination were discussed. The content of Pb and the variation of composition were explored by means of atomic absorption spectroscopy (AAS) and X-ray diffraction. The results show that a number of Pb emits during cement calcination, F and C1 promote the emission of Pb, and Pb is enriched in kiln dust. The smaller the particle of kiln dust, the higher the content of Pb. When utilizing the raw materials with a high content of Pb, a more efficient dust collector should be used and the kiln dust should be used as the addition of cement. Pb in clinker is enriched in the intermediate phase. The reduction of silica modulus is useful to increase the solidification content of Pb in clinker. The solidification content of Pb in calcium sulphoaluminate mineral is higher than that in calcium aluminate mineral.

  12. Hydration of ordinary portland cements made from raw mix containing transition element oxides

    Energy Technology Data Exchange (ETDEWEB)

    Kakali, G.; Tsivilis, S.; Tsialtas, A. [National Technical Univ. of Athens (Greece)

    1998-03-01

    The use of industrial wastes, such as waste tires, waste oil, non-ferrous metal slag, or waste molding sand, as alternative raw materials and fuel in cement plants has been established from an environmental and recycling point of view and is expected to increase in the future. Cement is broadly used, among other hydraulic binders, in the solidification and stabilization of industrial and municipal wastes. This tendency to the use of wastes in the cement industry or the utilization of cement for the handling of wastes has led to the presence of several transition element compounds in the clinker and/or in the hydrated cement. The subject of this paper is the study of the hydration process in cements made from raw mixes containing transition element oxides. The oxides used are ZrO{sub 2}, V{sub 2}O{sub 5}, Ni{sub 2}O{sub 3}, CuO, Co{sub 2}O{sub 3}, MnO, Cr{sub 2}O{sub 3}, TiO{sub 2}, MoO{sub 3}, and ZnO, and their percentage in the raw mixes is 2% w/w. The cement pastes are cured in water for 24 h, 48 h, 7 days and 28 days. Hydration rate and products are studied by means of X-ray diffraction, differential scanning calorimetry, and thermogravimetric analysis. As it is concluded, the added oxides provoke, in general, a retardation of the hydration reactions. The effect is stronger during the first 2 days and becomes negligible at 28 days. The addition of CuO strongly delays the hydration even after 28 days. Its action is related to the formation of Cu(OH){sub 2} during the first days of hydration.

  13. Magnetic properties of the lichen Pseudevernia furfuracea transplanted near a cement plant in NE Italy

    Science.gov (United States)

    Winkler, Aldo; Kodnik, Danijela; Candotto Carniel, Fabio; Tretiach, Mauro

    2015-04-01

    The magnetic properties of transplanted samples of the epiphytic lichen Pseudevernia furfuracea (L.) Zopf var. furfuracea have been analyzed in the framework of a biomonitoring study in NE Italy focused on a middle-sized cement plant (clinker production: 556,000 ton year-1 in 2012). The lichen transplants were exposed for 2 months in 40 sites distributed all around the cement plant: 37 sites were located at the knots of a 700 m step grid covering agricultural, forest and urban areas and a large industrial zone, and 3 sites were located in the nearby urban centers. The elemental analysis of the exposed samples revealed a limited impact of the cement plant on the territory, while that of the industrial zone, located in the SW corner of the study area, seemed to be generally stronger. The magnetic properties of the transplanted lichens statistically agree with the elemental concentration dataset, showing that the cement plant has no significant impact on the magnetic properties of the lichens transplanted in the whole area. The samples from the industrial area show the highest values of magnetic susceptibility and of saturation magnetization and saturation remanent magnetization, in coherence with the spatial distribution of the elemental concentration values. The magnetic mineralogy is reasonably uniform throughout the whole set of samples, and is dominated by magnetite-like minerals. The magnetic mineralogy of the sample nearest to the cement plant is not magnetically distinguishable from that of the other lichen samples and does not seem to be linked to the magnetic properties of the cement therein produced. The full agreement between the magnetic and elemental datasets underlines a modest environmental impact of the cement plant, with respect to the other industrial activities in the same area.

  14. Investigation of the hydration and bioactivity of radiopacified tricalcium silicate cement, Biodentine and MTA Angelus.

    Science.gov (United States)

    Camilleri, Josette; Sorrentino, François; Damidot, Denis

    2013-05-01

    calcium silicate was higher for Biodentine™ than for TCS-20-Z owing to its optimized particle size distribution, the presence of CaCO₃ and the use of CaCl₂. Tricalcium calcium silicate in MTA hydrated even more slowly than TCS-20-Z as evident from the size of reaction rim representative of calcium silicate hydrate (C-S-H) around tricalcium silicate grains and the calorimetry measurements. On the other hand, calcium oxide contained in MTA Angelus™ hydrated very fast inducing an intense exothermic reaction. Calcium hydroxide was produced as a by-product of reaction in all hydrated cements but in greater quantities in MTA due to the hydration of calcium oxide. This lead to less dense microstructure than the one observed for both Biodentine™ and TCS-20-Z. All the materials were bioactive and allowed the deposition of hydroxyapatite on the cement surface in the presence of simulated body fluid and the radiopacity was greater than 3mm aluminum thickness. All the cement pastes tested were composed mainly of tricalcium silicate and a radiopacifier. The laboratory manufactured cement contained no other additives. Biodentine™ included calcium carbonate which together with the additives in the mixing liquid resulted in a material with enhanced chemical properties relative to TCS-20-Z prototype cement. On the other hand MTA Angelus™ displayed the presence of calcium, aluminum and silicon oxides in the un-hydrated powder. These phases are normally associated with the raw materials indicating that the clinker of MTA Angelus™ is incompletely sintered leading to a potential important variability in its mineralogy depending on the sintering conditions. As a consequence, the amount of tricalcium silicate is less than in the two other cements leading to a slower reaction rate and more porous microstructure. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  15. The Stabilizing Granular Soil with Slow-setting and Slight-expansive Cement

    Institute of Scientific and Technical Information of China (English)

    ZHOU Ming-kai; SHENG Wei-guo; TIAN Zhong-qing

    2002-01-01

    According to the characteristics of granular soil, the technological requirements of the specialpurpose cement for stabilizing granular soil are pat forward to meet the demands of implementation of highway base engineering. A kind of slow-setting and slight-expansive cement is developed by the cross experiment method in slag-clinker-gypsum-alkaline system, the final setting time of the cement can be prolonged to 8 h, and it has properties of low dry shrirkage , high flexural strength and good crack resistance. The strength of granular soil stabilized by the cement is increased by 20% compared with that stabilized by Chinese 425-Grade slag cement.

  16. Long-term Performance of Moderate Heat Portland Cement with Double-expansive Sources

    Institute of Scientific and Technical Information of China (English)

    YE Qing; CHEN Huxing; KONG Deyu; WANG Shangxian; LOU Zonghan

    2007-01-01

    The long-term performance of moderate heat Portland cement with double-expansive sources (DE cement) in the system of high MgO clinker and gypsum was studied by XRD, SEM/EDAX and test methods for strength and expansion of cement. Results indicate that the periclase particle, whose size was 5-7.5 μm in DE cement clinker containing 4.8 % MgO, existed individually. The periclase hydration in hardened DE cement paste started at about 60 days and completed up to 2 000 days, and ettringite in the paste was stable from 3 days to 2 000 days. Under the conditions of 4.5%-5.0 % MgO in clinker and 2.8%-3.4 %SO3 in cement,ettringite expansion and brucite expansion in DE cement paste had a continuity, entirety and stability. At the ages of 90, 365, 730 and 2 000 days the expansion of the paste reached 0.07%-0.11%, 0.16%-0.21%, 0.21%-0.27% and 0.29%-0.38 %, respectively. The results suggest that by using this cement in mass concrete it may compensate its temperature shrinkage and autogenous shrinkage to some extent.

  17. Thoracic dust exposure is associated with lung function decline in cement production workers.

    Science.gov (United States)

    Nordby, Karl-Christian; Notø, Hilde; Eduard, Wijnand; Skogstad, Marit; Fell, Anne Kristin; Thomassen, Yngvar; Skare, Øivind; Bergamaschi, Antonio; Pietroiusti, Antonio; Abderhalden, Rolf; Kongerud, Johny; Kjuus, Helge

    2016-08-01

    We hypothesised that exposure to workplace aerosols may lead to lung function impairment among cement production workers.Our study included 4966 workers in 24 cement production plants. Based on 6111 thoracic aerosol samples and information from questionnaires we estimated arithmetic mean exposure levels by plant and job type. Dynamic lung volumes were assessed by repeated spirometry testing during a mean follow-up time of 3.5 years (range 0.7-4.6 years). The outcomes considered were yearly change of dynamic lung volumes divided by the standing height squared or percentage of predicted values. Statistical modelling was performed using mixed model regression. Individual exposure was classified into quintile levels limited at 0.09, 0.89, 1.56, 2.25, 3.36, and 14.6 mg·m(-3), using the lowest quintile as the reference. Employees that worked in administration were included as a second comparison group.Exposure was associated with a reduction in forced expiratory volume in 1 s (FEV1), forced expiratory volume in 6 s and forced vital capacity. For FEV1 % predicted a yearly excess decline of 0.84 percentage points was found in the highest exposure quintile compared with the lowest.Exposure at the higher levels found in this study may lead to a decline in dynamic lung volumes. Exposure reduction is therefore warranted.

  18. PIXE characterization of by-products resulting from the zinc recycling of industrial cemented carbides

    Energy Technology Data Exchange (ETDEWEB)

    Freemantle, C.S. [School of Chemical & Metallurgical Engineering and DST-NRF Centre of Excellence in Strong Materials, University of the Witwatersrand, P/Bag 3, Wits 2050 (South Africa); Pilot Tools (Pty) (Ltd), P.O. Box 27420, Benrose 2011 (South Africa); Sacks, N. [School of Chemical & Metallurgical Engineering and DST-NRF Centre of Excellence in Strong Materials, University of the Witwatersrand, P/Bag 3, Wits 2050 (South Africa); Topic, M. [iThemba LABS, National Research Foundation, P.O. Box 722, Somerset West 7129 (South Africa); Pineda-Vargas, C.A. [iThemba LABS, National Research Foundation, P.O. Box 722, Somerset West 7129 (South Africa); Faculty of Health & Wellness Sciences, CPUT, Bellville (South Africa)

    2015-11-15

    By-product materials of the widely used zinc recycling process of cemented carbides have been studied. Scanning electron microscopy and micro-PIXE techniques have identified elemental concentrations, distributions and purity of by-product materials from an industrial zinc recycling plant. Cobalt surface enrichment, lamellar microstructures of varying composition, including alternating tungsten carbide (WC) grains and globular cobalt, and regions of excess zinc contamination were found in materials with incomplete zinc penetration. Liquid Co–Zn formation occurred above 72 wt.% Zn at the furnace temperature of 930 °C, and was extracted towards the surface of poorly zinc infiltrated material, primarily by the vacuum used for zinc distillation. Surface enrichment was not observed in material that was zinc infiltrated to the sample center, which was more friable and exhibited more homogeneous porosity and elemental concentrations. The result of incomplete zinc infiltration was an enriched surface zone of up to 60 wt.% Co, compared to an original sample composition of ∼10–15 wt.% Co. The impact on resulting powders could be higher or inhomogeneous cobalt content, as well as unacceptably high zinc concentrations. PIXE has proven it can be a powerful technique for solving industrial problems in the cemented carbide cutting tool industry, by identifying trace elements and their locations (such as Zn to 0.1 wt.% accuracy), as well as the distribution of major elements within WC–Co materials.

  19. In vitro biodurability of the product of thermal transformation of cement-asbestos.

    Science.gov (United States)

    Gualtieri, Alessandro F; Viani, Alberto; Sgarbi, Giulia; Lusvardi, Gigliola

    2012-02-29

    To safely recycle the product of the thermal transformation of cement-asbestos as secondary raw material, its toxicity potential should be assessed by in vitro biodurability tests. In this work, the acellular in vitro biodurability of the products of transformation of cement-asbestos at 1200 °C (named KRY·AS) was tested using both inorganic and organic simulated lung fluids at pH 4.5. The dissolution kinetics were followed using chemical, mineralogical and microstructural analyses. The total dissolution time estimated from the experiments with inorganic HCl diluted solution is one order of magnitude higher than that determined from the experiments with buffered Gamble solution (253 days vs. 20 days). The key parameter determining the difference in dissolution rate turns out to be the solidus/liquidus ratio which prompts a fast saturation of the solution with monosilicic acid. The calculated dissolution rate constants showed that the biodurability in vitro of KRY·AS is much lower with respect to that of standard chrysotile asbestos (total estimated dissolution time of 20 days vs. 298 days, respectively). This proves a low potential toxicity of this secondary raw material.

  20. FUZZY LOGIC CONTROLLER AS MODELING TOOL FOR THE BURNING PROCESS OF A CEMENT PRODUCTION PLANT

    Directory of Open Access Journals (Sweden)

    P.B. Osofisan

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: A comprehensive optimisation of the cement production process presents a problem since the input variables as well as the output variables are non-linear, interdependent and contain uncertainties. To arrive at a solution, a Fuzzy Logic controller has been designed to achieve a well-defined relationship between the main and vital variables through the instrumentality of a Fuzzy Model. The Fuzzy Logic controller has been simulated on a digital computer using MATLAB 5.0 Fuzzy Logic Tool Box, using data from a local cement production plant.

    AFRIKAANSE OPSOMMING: Die omvattende optimisering van 'n proses wat sement vervaardig, word beskryf deur nie-linieêre inset- en uitsetveranderlikes wat onderling afhanklik is, en ook van onsekere aard is. Om 'n optimum oplossing te verkry, word 'n Wasigheidsmodel gebruik. Die model word getoets deur gebruik te maak van die MATLAB 5.0 Fuzzy Logic Tool Box en data vanaf 'n lokale sementvervaardigingsaanleg.

  1. Ergonomic analysis in the manual transport of loads: a case study in a cement production company

    Directory of Open Access Journals (Sweden)

    Jarbas Rocha Martins

    2017-03-01

    Full Text Available This study aims to analyze the manual transport activity of 50kg bags in a cement production company by means of ergonomic work analysis (EWA, identifying environmental factors and loaders’ working conditions. In order for EWA to take place, photographic records, videos and interviews were performed. It covered aspects related to lifting, transportation and handling of cement bags, as well as observations of loaders’ posture while performing the activity. In this sense, both qualitative and quantitative aspects were taken into account, which were evidenced by the use of instruments for determining the concentration of agents in the environment. In addition, some management tools, such as the cause and effect diagram, and interviews conducted during the field research were used. It was found that the high rate of absenteeism in the activity is related to the strict control of productivity, the excessive lifting and manual transport of weights, and repetitive trunk flexion movements. The results shown by the EWA made it possible to propose preventive measures and some changes in the work environment.

  2. PIXE characterization of by-products resulting from the zinc recycling of industrial cemented carbides

    Science.gov (United States)

    Freemantle, C. S.; Sacks, N.; Topic, M.; Pineda-Vargas, C. A.

    2015-11-01

    By-product materials of the widely used zinc recycling process of cemented carbides have been studied. Scanning electron microscopy and micro-PIXE techniques have identified elemental concentrations, distributions and purity of by-product materials from an industrial zinc recycling plant. Cobalt surface enrichment, lamellar microstructures of varying composition, including alternating tungsten carbide (WC) grains and globular cobalt, and regions of excess zinc contamination were found in materials with incomplete zinc penetration. Liquid Co-Zn formation occurred above 72 wt.% Zn at the furnace temperature of 930 °C, and was extracted towards the surface of poorly zinc infiltrated material, primarily by the vacuum used for zinc distillation. Surface enrichment was not observed in material that was zinc infiltrated to the sample center, which was more friable and exhibited more homogeneous porosity and elemental concentrations. The result of incomplete zinc infiltration was an enriched surface zone of up to 60 wt.% Co, compared to an original sample composition of ∼10-15 wt.% Co. The impact on resulting powders could be higher or inhomogeneous cobalt content, as well as unacceptably high zinc concentrations. PIXE has proven it can be a powerful technique for solving industrial problems in the cemented carbide cutting tool industry, by identifying trace elements and their locations (such as Zn to 0.1 wt.% accuracy), as well as the distribution of major elements within WC-Co materials.

  3. Macrodefect-free cements: chemistry and impact of the environment

    Energy Technology Data Exchange (ETDEWEB)

    Drabik, M.; Galikova, L.; Mojumdar, S.C. [Slovak Academy of Sciences, Bratislava (Slovakia). Inst. of Inorganic Chemistry

    2002-07-01

    To control and improve the moisture resistance is a long felt necessity of the MDF cements, chemical approaches together with material science contribute to the progress. Present results support our previous hypothesis about the impregnation or barier effect of poly-P on the MDF cements and enlarge the validity of this hypothesis to the blends of SAFB clinker, Portland cement and HPMC or poly-P. Compactness of Al(Fe)-O-P cross-links increases the intrinsic density and, consequently, impregnates the system against the uptake of moisture. In a sense of the theory of functional polymers, the intensity of grafting of polymer chains to the surface of grains increases if poly-P is used and with the prolonged processing. The scope of moisture attack on MDF cements synthesized from the blends of SAFB clinker, Portland cement and HPMC or poly-P, as quantified using mass changes as measure of moisture resistance, is strongly affected by the nature of polymer. The addition of Portland cement in the raw mix improves the moisture resistance of MDF cements. Thermal analysis shows: (i) the irreversible mass gain of 3 - 10% is arisen from carbonation and secondary hydration of cement grains and (ii) the Al(Fe)-O-C(P) cross-links remain intact in the moist environment at either ambient or extreme levels of humidity. (orig.)

  4. Cement As a Waste Form for Nuclear Fission Products: The Case of (90)Sr and Its Daughters.

    Science.gov (United States)

    Dezerald, Lucile; Kohanoff, Jorge J; Correa, Alfredo A; Caro, Alfredo; Pellenq, Roland J-M; Ulm, Franz J; Saúl, Andrés

    2015-11-17

    One of the main challenges faced by the nuclear industry is the long-term confinement of nuclear waste. Because it is inexpensive and easy to manufacture, cement is the material of choice to store large volumes of radioactive materials, in particular the low-level medium-lived fission products. It is therefore of utmost importance to assess the chemical and structural stability of cement containing radioactive species. Here, we use ab initio calculations based on density functional theory (DFT) to study the effects of (90)Sr insertion and decay in C-S-H (calcium-silicate-hydrate) in order to test the ability of cement to trap and hold this radioactive fission product and to investigate the consequences of its β-decay on the cement paste structure. We show that (90)Sr is stable when it substitutes the Ca(2+) ions in C-S-H, and so is its daughter nucleus (90)Y after β-decay. Interestingly, (90)Zr, daughter of (90)Y and final product in the decay sequence, is found to be unstable compared to the bulk phase of the element at zero K but stable when compared to the solvated ion in water. Therefore, cement appears as a suitable waste form for (90)Sr storage.

  5. Some durability aspects of hybrid alkaline cements

    Directory of Open Access Journals (Sweden)

    Donatello S.

    2014-04-01

    Full Text Available Blended cements that contain a high content of fly ash and a low content of Portland cement typically suffer from low early strength development and long setting times. Recently, one method of overcoming these problems has been to use an alkali activator to enhance the reactivity of fly ash particles at early ages. Such cements can be grouped under the generic term “hybrid alkaline cements”, where both cement clinker and fly ash, encouraged by the presence of alkalis, are expected to contribute to cementitious gel formation. The work presented here examines some of the durability aspects of high fly ash content hybrid alkaline cement. Specifically, the aspects investigated were: exposure at high temperatures (up to 1000°C, resistance to immersion in aggressive solutions and susceptibility to the alkali aggregate reaction. All tests were repeated with a commercially available sulfate resistant Portland cement for comparison. When exposed to high temperatures, the hybrid alkaline cement showed strikingly different behaviour compared to the control Portland cement, showing fewer micro-cracks and maintaining residual compressive strengths at least equal to original strengths. Beyond 700°C, the hybrid alkaline cement began to sinter, which resulted in shrinkage of around 5% and a 100% increase in residual compressive strengths. No such sintering event was noted in the control Portland cement, which showed a drastic loss in residual compressive strengths upon heating. In immersion tests, the hybrid alkaline cement possessed excellent resistance to sulfate and seawater attack, similar to the control sulfate resistant cement. Both cements were however severely degraded by immersion in 0.1M HCl for 90 days. Both binders complied with the accelerated alkali-aggregate test but when this test was extended, the hybrid alkaline binder showed much greater dimensional stability. Possible reasons for the differences in durability behaviour in both cements

  6. Industrial transformation and green production to reduce environmental emissions:Taking cement industry as a case

    Institute of Scientific and Technical Information of China (English)

    LU¨ Yong-Long; GENG Jing; HE Gui-Zhen

    2015-01-01

    Industrial transformation and green production (ITGP) is a new 10-year international research initiative proposed by the Chinese National Committee for Future Earth. It is also an important theme for adapting and responding to global environmental change. Aiming at a thorough examination of the implementation of ITGP in China, this paper presents its objectives, its three major areas, and their progress so far. It also identifies the key elements of its management and proposes new perspectives on managing green transformation. For instance, we introduce a case study on cement industry that shows the positive policy effects of reducing backward production capacity on PCDD/Fs emissions. Finally, to develop different transformation scenarios for a green future, we propose four strategies:1) policy integration for promoting green industry, 2) system innovation and a multidisciplinary approach, 3) collaborative governance with all potential stakeholders, and 4) managing uncertainty, risks, and long-time horizons.

  7. Industrial transformation and green production to reduce environmental emissions: Taking cement industry as a case

    Directory of Open Access Journals (Sweden)

    Yong-Long Lü

    2015-09-01

    Full Text Available Industrial transformation and green production (ITGP is a new 10-year international research initiative proposed by the Chinese National Committee for Future Earth. It is also an important theme for adapting and responding to global environmental change. Aiming at a thorough examination of the implementation of ITGP in China, this paper presents its objectives, its three major areas, and their progress so far. It also identifies the key elements of its management and proposes new perspectives on managing green transformation. For instance, we introduce a case study on cement industry that shows the positive policy effects of reducing backward production capacity on PCDD/Fs emissions. Finally, to develop different transformation scenarios for a green future, we propose four strategies: 1 policy integration for promoting green industry, 2 system innovation and a multidisciplinary approach, 3 collaborative governance with all potential stakeholders, and 4 managing uncertainty, risks, and long-time horizons.

  8. The effect of polymethylsiloxanes on hydration of clinker phases

    Science.gov (United States)

    Stoch, A.; Zdaniewicz, M.; Paluszkiewicz, Cz.

    1999-11-01

    The effect of the polydimethylsiloxane (PDMS) admixture on hydration of pure clinker phases: alite, belite or tricalcium aluminate was studied by means of FTIR spectroscopy. It was shown that PDMS, introduced to a clinker phase paste during the hydration process reduces the carbonation reaction, improves the crystallization of hydrates in tricalcium aluminate and considerably increases water resistance without significantly changing the mechanical parameters. Our FTIR results were also confirmed by XRD, DTA and SEM study of the morphology of the newly formed phases. Introduction of as much as 5 wt.% of the PDMS increases the wetting angle by up to 80-120°.

  9. Electron microscopy of clinker by the replica technique

    Directory of Open Access Journals (Sweden)

    KittI, P.

    1972-12-01

    Full Text Available Not availableUsando la técnica de réplicas y su observación posterior con un microscopio electrónico, se muestran los efectos de varios ataques sobre un clinker de enfriamiento rápido y otro lento. Se discuten las observaciones realizadas y se muestran los resultados de varios ataques. Se hace notar la gran precisión con que se pueden observar los detalles estructurales con este método y, por lo tanto, la exactitud con que se puede clasificar un clinker.

  10. Characterization of basic oxygen furnace slag and granite waste mixtures to Portland cement production

    Directory of Open Access Journals (Sweden)

    Luiz Alberto Baptista Pinto Junior

    Full Text Available Abstract The aim of this paper is to analyze mixtures of basic oxygen furnace slag and granite waste in order to produce Portland cement. X-ray patterns were carried out in both the basic oxygen furnace slag and granite waste. Then, mixtures were prepared to obtain the binary basicity of 0.5, 0.9 and 1.2. The mixtures were melted at 1500ºC. Two cooling steps were performed. The first cooling step was accomplished inside the furnace in order to determine the phases formed during the melting step. The second cooling process was carried out in water in order to obtain an amorphous structure. Images via scanning electrons microscopy and EDS spectrum were obtained for the mixtures cooling in water. The results showed that basic oxygen furnace slag contains a higher percent of CaO. A binary basicity of 4.6 was determined. The granite waste appeared as mainly a quartz phase. During the slow cooling step, silicates (akermanite and gehlenite were formed. On the fast cooling step, amorphous structures were obtained. In addition, images obtained via scanning electrons microscopy showed glass structures. EDS spectrum indicated that the glass structures were composed for calcium silicates. Thus, the results suggest that mixtures using basic oxygen furnace slag and granite waste presented characteristics desirable for Portland cement production.

  11. Influence of wollastonite on the mechanical strength of the cement stonemade of portland cement clinker Влияние волластанита на механическую прочность цементного камня, изготовленного из портландцементного клинкера

    Directory of Open Access Journals (Sweden)

    Berdov Gennadiy Il’ich

    2013-03-01

    Full Text Available The authors have completed a research into the influence of wollastonite onto the strength of the cement stone, if the latter is freshly made or stored in the humid environment for four months. The authors believe that the optimal share of the wollastonite admixture is equal to 5…9 %.The strength of wollastonite-free clinker samples is not reduced, if the clinker is stored in the humid environment and exposed to heat and moisture treatment. Upon the expiry of the 28-days’ curing period, the strength of samples is down by 4 % in the regular environment. In this case, the wollastonite admixture (7 % improves the strength of samples upon the expiry of the 28 days’ curing period and their strength goes up by28 %, while the strength of samples goes up by 17 % upon their exposure to heat and moisture treatment.The authors believe that the influence produced by wollastonite may be explained by the following reasons. In the event that freshly milled powder (clinker is added, wollastonite produces its influence on the hydration process, as formation of new compounds (hydrates is influenced by a strong adsorption field of wollastonite particles.If clinker is stored in the humid environment, its substantial share is subject to hydration and carbonization.Исследовано влияние введения добавки волластонита (2…11 масс. % на повышение прочности цементного камня, изготовленного как на свежеприготовленном клинкере, так и на хранившемся 4 месяца во влажных условиях. Оптимальным количеством добавки волластонита является 5…9 масс. %.

  12. Heuristic economic assessment of the Afghanistan construction materials sector: cement and dimension stone production

    Science.gov (United States)

    Mossotti, Victor G.

    2014-01-01

    Over the past decade, the U.S. Government has invested more than $106 billion for physical, societal, and governmental reconstruction assistance to Afghanistan (Special Inspector General for Afghanistan Reconstruction, 2012a). This funding, along with private investment, has stimulated a growing demand for particular industrial minerals and construction materials. In support of this effort, the U.S. Geological Survey released a preliminary mineral assessment in 2007 on selected Afghan nonfuel minerals (Peters and others, 2007). More recently, the 2007 mineral assessment was updated with the inclusion of a more extensive array of Afghan nonfuel minerals (Peters and others, 2011). As a follow-up on the 2011 assessment, this report provides an analysis of the current use and prospects of the following Afghan industrial minerals required to manufacture construction materials: clays of various types, bauxite, gypsum, cement-grade limestone, aggregate (sand and gravel), and dimension stone (sandstone, quartzite, granite, slate, limestone, travertine, marble). The intention of this paper is to assess the: Use of Afghan industrial minerals to manufacture construction materials, Prospects for growth in domestic construction materials production sectors, Factors controlling the competitiveness of domestic production relative to foreign imports of construction materials, and Feasibility of using natural gas as the prime source of thermal energy and for generating electrical energy for cement production. The discussion here is based on classical principles of supply and demand. Imbedded in these principles is an understanding that the attributes of supply and demand are highly variable. For construction materials, demand for a given product may depend on seasons of the year, location of construction sites, product delivery time, political factors, governmental regulations, cultural issues, price, and how essential a given product might be to the buyer. Moreover, failure on the

  13. Effect of mineral additives (natural pozzolana and sand of dunes) by substitution of cement on the performance and durability of mortars

    Science.gov (United States)

    Saidi, M.; Safi, B.

    2016-04-01

    The objective of our work consists of the study of the substitution effects of clinker by mineral additions such as: natural pozzolana (PZ) and the sand of dunes (SD) finely crushed on the mechanical properties and the durability of the mortars worked out according to various combinations containing these additions. The results from this research confirm that the substitution of 20% to 30% of cement APC (Artificial Portland Cement) by additions in binary cement (APC + PZ) or ternary (APC + PZ + SD) contributes positively to the mechanical strength of mortars and resistance to the chemical attacks in various corrosive conditions such as: hydrochloric acid, sulfuric acid and nitric acid. The mechanical strength of the different variants is comparable to those of the APC. The test results of the weight loss and phenolphthalein shows that the chemical resistance of variants (PZ20) and (PZ20 with SD5) are larger compared to the reference mortar APC and other variants. This study shows that adding value by substituting a part of clinker. This substitution can save 20% to 30% of clinker used for the manufacture of cement; this will have a beneficial effect for cement and economically (less energy spent for the clinker burning). This study contributes to the protection of the environment as to produce one ton of clinker generates about one ton of CO2 is harmful to the atmosphere. Based on our results we will reduce from 20% to 30% CO2 gas responsible for the greenhouse effect.

  14. Cement Production and Sustainable Rural Farming Livelihood in Nigeria: Striking a Sensible Balance Through Environmental Legislation and Enforcement

    Directory of Open Access Journals (Sweden)

    Luke O. Okojie

    2014-10-01

    Full Text Available This paper undertook the damage valuation of cement production induced air pollution on rural farming livelihood, assessed the impact on farmers’ profitability as well as investigating the corporate social responsibility investment of the cement companies in the producing host communities in Nigeria. It then examined how legislation and enforcement can be made to strike a sensible balance between the environmental damage enabled by cement pollution and ensuring a sustainable farming livelihood. A two stage simple random sampling procedure was adopted for the paper to select a total of 120 respondentsin the target and control areas. Data were analyzed using descriptive statistics, Dichotomous–Choice Contingent Valuation Method (DC- CVM that terminated into the logit model and the budgetary analysis. The total Willingness-To-Pay (WTP/annum to avert the negative externalities on the host communities’ farming livelihood was N3.21 billion. The profitability in farming in the target cement producing area with respect to thenet farm income and the rate of return to capital investment were lower in the target as compared to the control area. The Corporate Social Responsibility (CSR investments ofthe cement producing companies were small compared to the profits realized by them. The proportions of the CSR investments with respect to the company’s profits were between 0.4% and 1.6% for the five years considered in the paper. Efforts have been made by the government to enact laws, regulations and standards to ensureenvironmentally sound and sustainable environment though the institution initially put in place to implement them was not given legal powers of enforcement. Things are however changing with the establishment of another with such powers. It is only by such proper implementation, a sensible balance can be struck between uncontrolled cement dust pollution associated with excess profits to the cement producers and sustainable

  15. Hydration of fly ash cement

    Energy Technology Data Exchange (ETDEWEB)

    Etsuo Sakai; Shigeyoshi Miyahara; Shigenari Ohsawa; Seung-Heun Lee; Masaki Daimon [Tokyo Institute of Technology, Tokyo (Japan). Department of Metallurgy and Ceramics Science, Graduate School of Science and Engineering

    2005-06-01

    It is necessary to establish the material design system for the utilization of large amounts of fly ash as blended cement instead of disposing of it as a waste. Cement blended with fly ash is also required as a countermeasure to reduce the amount of CO{sub 2} generation. In this study, the influences of the glass content and the basicity of glass phase on the hydration of fly ash cement were clarified and hydration over a long curing time was characterized. Two kinds of fly ash with different glass content, one with 38.2% and another with 76.6%, were used. The hydration ratio of fly ash was increased by increasing the glass content in fly ash in the specimens cured for 270 days. When the glass content of fly ash is low, the basicity of glass phase tends to decrease. Reactivity of fly ash is controlled by the basicity of the glass phase in fly ash during a period from 28 to 270 days. However, at an age of 360 days, the reaction ratios of fly ash show almost identical values with different glass contents. Fly ash also affected the hydration of cement clinker minerals in fly ash cement. While the hydration of alite was accelerated, that of belite was retarded at a late stage.

  16. Energy efficiency and carbon dioxide emissions reduction opportunities in the U.S. cement industry

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Nathan; Worrell, Ernst; Price, Lynn

    1999-08-01

    This paper reports on an in-depth analysis of the U.S. cement industry, identifying cost-effective energy efficiency measures and potentials. The authors assess this industry at the aggregate level (Standard Industrial Classification 324), which includes establishments engaged in manufacturing hydraulic cements, including Portland, natural, masonry, and pozzolana when reviewing industry trends and when making international comparisons. Coal and coke are currently the primary fuels for the sector, supplanting the dominance of natural gas in the 1970s. Between 1970 and 1997, primary physical energy intensity for cement production (SIC 324) dropped 30%,from 7.9 GJ/t to 5.6 GJ/t, while carbon dioxide intensity due to fuel consumption (carbon dioxide emissions expressed in tons of carbon per ton cement) dropped 25%, from 0.16 tC/ton to 0.12 tC/ton. Carbon dioxide intensity due to fuel consumption and clinker calcination dropped 17%, from 0.29 tC/ton to 0.24 tC/ton. They examined 30 energy efficient technologies and measures and estimated energy savings, carbon dioxide savings, investment costs, and operation and maintenance costs for each of the measures. They constructed an energy conservation supply curve for U.S. cement industry which found a total cost-effective reduction of 0.6 GJ/ton of cement consisting of measures having a simple payback period of 3 years or less. This is equivalent to potential energy savings of 11% of 1994 energy use for cement making and a savings of 5% of total 1994 carbon dioxide emissions by the U.S. cement industry. Assuming the increased production of blended cement in the U.S., as is common in many parts of the world, the technical potential for energy efficiency improvement would not change considerably. However, the cost-effective potential, would increase to 1.1 GJ/ton cement or 18% of total energy use, and carbon dioxide emissions would be reduced by 16%.

  17. Development of a Laboratory Cement Quality Analysis Apparatus Based on Laser-Induced Breakdown Spectroscopy

    Science.gov (United States)

    Fan, Juanjuan; Zhang, Lei; Wang, Xin; Li, Yufang; Gong, Yao; Dong, Lei; Ma, Weiguang; Yin, Wangbao; Wang, Zhe; Li, Zheng; Zhang, Xiangjie; Li, Yi; Jia, Suotang

    2015-11-01

    Determination of the chemical composition of cement and ratio values of clinker plays an important role in cement plants as part of the optimal process control and product quality evaluation. In the present paper, a laboratory laser-induced breakdown spectroscopy (LIBS) apparatus mainly comprising a sealed optical module and an analysis chamber has been designed for possible application in cement plants for on-site quality analysis of cement. Emphasis is placed on the structure and operation of the LIBS apparatus, the sealed optical path, the temperature controlled spectrometer, the sample holder, the proper calibration model established for minimizing the matrix effects, and a correction method proposed for overcoming the ‘drift’ obstacle. Good agreement has been found between the laboratory measurement results from the LIBS method and those from the traditional method. The absolute measurement errors presented here for oxides analysis are within 0.5%, while those of ratio values are in the range of 0.02 to 0.05. According to the obtained results, this laboratory LIBS apparatus is capable of performing reliable and accurate, composition and proximate analysis of cement and is suitable for application in cement plants. supported by National Natural Science Foundation of China (Nos. 61127017, 61378047, 61205216, 61178009, 61108030, 61475093, and 61275213), the National Key Technology R&D Program of China (No. 2013BAC14B01), the 973 Program of China (No. 2012CB921603), the Shanxi Natural Science Foundation, China (Nos. 2013021004-1, 2012021022-1), and the Shanxi Scholarship Council of China (Nos. 2013-011 and 2013-01)

  18. Severe particulate pollution from deposition practices of primary materials of cement plants

    Science.gov (United States)

    Kourtidis, Konstantinos; Rapsomanikis, Spyridon; Zerefos, Christos; Georgoulias, Aristeidis; Pavlidou, Eleni

    2014-05-01

    Analysis of ambient particulates sampled at a residential area near a cement manufacturing plant in Greece, showed total aerosol mass in the sampled air 1.3-30.4 mg/m3 and PM10 concentrations 0.04-3 mg/m3. These concentrations are very high and seriously exceed air quality standards. Morphological examination and elemental analysis of air samples and primary materials with Scanning Electron Microscopy (SEM)/Energy Dispersive X-Ray Spectroscopy (EDS) showed that ambient particulates shared appearance features and had similar elemental synthesis to clinker and fly ash, showing heavy impacts on the ambient aerosol load from the cement plant practice of open deposition of primary materials. Satellite-derived AOD over the area during the period 2000-2010 shows extended spatial impact, while satellite overpass data indicate a 33% decrease in AOD over this period, possibly due to changing production and primary material deposition practices. Although the sampling was performed more than one decade ago in Greece, environmental legislation and its reinforcement practices at that time in Greece are similar to current ones in many parts of the world. The global increase in cement production, especially in south-east Asia, make these measurements particularly relevant.

  19. Resistance to chemical attack of bittern-resisting cement in high-bittern environment

    Institute of Scientific and Technical Information of China (English)

    Yunbing Hou; Bingwen Wang; Yu Chen; Botao Zhang; Lin Yu

    2005-01-01

    A new kind of bittern-resisting cement (BRC) was introduced. This material is based on the ternary cementitious system of clinker containing C4A3 -S phase, high-activity ground granulated blast-furnace slag (GGBFS) and fly ash (FA). The hydration process and the hydrated products of BRC were studied by means of XRD, TG-DTA and SEM, and the resistance to chemical attack of BRC in high-bittern environment was also examined. The corrosion experiment in seven kinds of brines proved that BRC exhibits an excellent resistance to chemical attack of bittern. The corrosion resistance factors were calculated and all of them were greater than 0.96. It showed that BRC totally controls the cement-based material corrosion in brines from four aspects: (1) making full use of the dominant complementation effect of mineral materials; (2) diminishing the hydrated products easy to be attacked; (3) improving the microstructure of hardened cement mortar; (4) degrading the chemical attack of bittern.

  20. SYNTHESIS AND CHARACTERIZATION OF HIGH BELITE SULFOALUMINATE CEMENT THROUGH RICH ALUMINA FLY ASH AND DESULFURIZATION GYPSUM

    Directory of Open Access Journals (Sweden)

    BING MA,

    2013-03-01

    Full Text Available The objective of this study was the preparation and characterization of high belite sulfoaluminate cement (HBSC from industrial residues. HBSC promises eco-friendly building materials with great mechanical performance at earlier ages than Ordinary Portland Cement (OPC. Preliminary results show the formation of main phase dicalcium silicate (C2S and ye’elimite (C4A3$ at 1250°C, as determined by X-ray diffraction (XRD, are promising. The formation of minerals in the clinker was analyzed by differential scanning calorimetry-thermogravimetry (DSC–TG. Likewise, Scanning electron microscope (SEM and XRD were used to carry out the analysis of the micro-structural and hydration products. The main HBSC hydration products, Ettringite and amorphous Al(OH3, were formed in the early stages; however, during the later stages, monosulfate and Strätlingite were formed. Isothermal conduction calorimetry measurements indicate that hydration properties of the cements are comparable to OPC; the total hydration heat after 3 days was 438 J/g. The optimum compressive strength values of the mortars after 1-, 3-, 7-, and 28-days were 24.9 MPa, 33.2 MPa, 35.6 MPa and 52.8 MPa which can meet the requirement of special structures.

  1. Basalt mine-tailings as raw-materials for Portland clinker Rejeitos da mineração de basalto como matérias-primas para clínquer Portland

    Directory of Open Access Journals (Sweden)

    F. R. D Andrade

    2010-03-01

    Full Text Available Large volumes of waste materials are produced by crushing of basaltic rocks for aggregate production, which is widely used in regions that lack rocks of granitic or gneissic composition. Two types of waste materials are produced (a quarry fines, which are in part used as fine aggregates in concrete and (b vesicular basalt, a porous variety of basalt that is useless as aggregate. This paper presents a procedure to use basaltic mine-tailings as raw-mixtures for Portland cement by adjusting the proportion of the other raw-materials (limestone, clay, iron ore. It is demonstrated that there is no need for additional fluxes to the basalt-bearing raw-mixtures, since the setting of the chemical parameters is enough to guarantee clinker formation. Two series of experimental clinkers were synthesized with raw-mixtures containing residues from a basalt quarry that produces aggregates for concrete. Experimental clinkers were produced from raw-mixtures with similar lime saturation factors, silica and alumina modules, which were set by adjusting the proportions of limestone, clay and iron ore to the varying proportions of basaltic materials added to them. One series of clinkers was made with basalt quarry fines, which are in part used as fine aggregate, but also accumulate as mine-tailings. Other series was made using vesicular (porous basalt, a variety not resistant enough to be used as aggregate. It is demonstrated that the basaltic composition is fully compatible with clinker production, and no addition of fluxes or other additions is required. Composition of the raw-mixtures was checked by chemical analysis. Quantitative phase analysis of the clinkers was made by optical microscopy point counting, together with qualitative X-ray diffraction. All mixtures produced clinkers with acceptable proportions of major and minor crystalline phases, inside the range of common industrial Portland clinkers.Duas séries de clínqueres experimentais foram sintetizadas

  2. Priority given to low energy and operating costs at la Cruz Azul Aguascalientes cement plant; Priorite aux faibles couts d`exploitation et d`energie pour la cimenterie la Cruz Azul d`Aguascalientes

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Luna, C.A. [La Cruz Azul (Mexico)

    1998-06-01

    The Mexican cement producer LA CRUZ AZUL decided for their third works located in Aguascalientes to design in co-operation with Krupp Polysius a 3,300 tpd production plant with minimum operating costs. This plant will have an energy consumption of less than 90 kWh per ton of cement and a heat consumption of approx. 700 kCal per kg of clinker, because an increase of energy costs is expected in the long term in Mexico. Main basic technical decisions concern material transport by mechanical conveyors, reuse of all hot gases generated for drying and very high automation level. Full-scale production is scheduled for mid-year 1999. (author)

  3. Recycling red mud from the production of aluminium as a red cement-based mortar.

    Science.gov (United States)

    Yang, Xiaojie; Zhao, Jianfeng; Li, Haoxin; Zhao, Piqi; Chen, Qin

    2017-05-01

    Current management for red mud is insufficient and a new method is needed. A series of experiments have been carried out to develop a new approach for effective management of red mud. Mortars without or with 3%, 6% and 9% red mud were prepared and their fresh and hardened properties were measured to access the possibility of recycling the red mud in the production of red cement-based mortar. The mechanisms corresponding to their mechanical performance variations were explored by X-ray powder diffraction and scanning electron microscopy. The results show that the fresh mortars with red mud present an increase of viscosity as compared with the control. However, little difference is found when the content of red mud is altered. It also can be seen that red mud increases flow time and reduces the slump flow of the mortar. Meanwhile, it is found that mortar with red mud is provided with higher air content. Red mud is eligible to adjust the decorative mortar colour. Compressive strength of mortar is improved when less than 6% red mud is added. However, overall it has a slightly negative effect on tensile bond strength. It decreases the Ca(OH)2 content and densifies the microstructure of hardened paste. The heavy metal concentrations in leachates of mortars with red mud are much lower than the values required in the standard, and it will not do harm to people's health and the environment. These results are important to recycle and effectively manage red mud via the production of red cement-based mortar.

  4. A method for obtaining isolation in production cementing; Sistematica para obtencao de isolamentos nas cimentacoes de producao

    Energy Technology Data Exchange (ETDEWEB)

    Lepeleire, Rubens de; Miletto, Antonio Luis Pires [PETROBRAS, XX (Brazil). Distrito de Perfuracao do Sudeste. Div. Tecnica

    1989-12-31

    This paper presents the procedure used to identify the factors that influenced the appearance of low isolation indexes, 59,1% in production cementing operations in Sao Mateus, during the year of 1987, bringing about a cost increase of over US$200,000.00 in primary cementing corrections. The various stages for the obtainment of such an index are analysed and the modifications that were considered necessary are presented. These modifications raised the index to 91,3% thus reducing correction costs to less than US$150,000.00 in 1988. From January to July, 1989, we able to obtain 98,9% of the isolations and an accumulated cementing correction cost of less than US$20,000.00. (author) 3 refs., 6 figs., 4 tabs.

  5. Study on the hydration product of cement in early age using TEM

    Institute of Scientific and Technical Information of China (English)

    HAN Song; YAN PeiYu; LIU RengGuang

    2012-01-01

    The morphology,crystallization and elemental composition of cement hydration products in early age including Ca(OH)2,CSH gel,AFt and AFm were investigated by transmission electron microscopy (TEM).Compared with the results from SEM and XRD,the TEM method and its advantage in the investigation of early hydration products were discussed.The results showed that TEM method is more accurate and reliable than SEM in the investigation of early hydration products.The CSH gel was confirmed to be amorphous foil-like shape product with a lot of crumples in early hydration age.Its Ca/Si ratio is 1.3±0.2.The morphology difference of AFt and AFm was clarified.AFt and AFm are both poly-crystal with layered structure,composed of disordered nano crystal.The size of nano crystal is less than 20 nm.The difference of Ca/Si ratio results between SEM and TEM was investigated,and its reason was explained.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-12-15

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

  7. Energy Efficiency Improvement and Cost Saving Opportunities for Cement Making. An ENERGY STAR Guide for Energy and Plant Managers

    Energy Technology Data Exchange (ETDEWEB)

    Galitsky, Christina; Worrell, Ernst; Galitsky, Christina

    2008-01-01

    The cost of energy as part of the total production costs in the cement industry is significant, warranting attention for energy efficiency to improve the bottom line. Historically, energy intensity has declined, although more recently energy intensity seems to have stabilized with the gains. Coal and coke are currently the primary fuels for the sector, supplanting the dominance of natural gas in the 1970s. Most recently, there is a slight increase in the use of waste fuels, including tires. Between 1970 and 1999, primary physical energy intensity for cement production dropped 1 percent/year from 7.3 MBtu/short ton to 5.3 MBtu/short ton. Carbon dioxide intensity due to fuel consumption and raw material calcination dropped 16 percent, from 609 lb. C/ton of cement (0.31 tC/tonne) to 510 lb. C/ton cement (0.26 tC/tonne). Despite the historic progress, there is ample room for energy efficiency improvement. The relatively high share of wet-process plants (25 percent of clinker production in 1999 in the U.S.) suggests the existence of a considerable potential, when compared to other industrialized countries. We examined over 40 energy efficient technologies and measures and estimated energy savings, carbon dioxide savings, investment costs, and operation and maintenance costs for each of the measures. The report describes the measures and experiences of cement plants around the wold with these practices and technologies. Substantial potential for energy efficiency improvement exists in the cement industry and in individual plants. A portion of this potential will be achieved as part of (natural) modernization and expansion of existing facilities, as well as construction of new plants in particular regions. Still, a relatively large potential for improved energy management practices exists.

  8. 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.

  9. Physico-mechanical and physico-chemical properties of synthesized cement based on plasma- and wet technologies

    Science.gov (United States)

    Sazonova, Natalya; Skripnikova, Nelli

    2016-01-01

    In this work we studied the influence of plasma-chemical technology of cement clinker synthesis under conditions of high-concentrated heat streams on the properties of cement on fixing such factors as raw-material type (chemical and mineralogical composition), fraction composition, homogenization and module characters of the raw-material mixture. In this connection the sludge of the cement plant in town Angarsk, based on which the cement clinker synthesis using the wet- and plasma-chemical technologies was performed, was used in the studies. The results of chemical X-ray-phase analysis, petrography of cement clinkers, differential scanning colorimetry of hardened cement paste are represented in this work. The analysis of building-technical properties of inorganic viscous substances was performed. It was found that in using the identical raw-material mixture the cement produced with temperature higher by 1650 °C than the traditional one may indicate the higher activity. The hardened cement paste compressive strength at the age of 28 days was higher than the strength of the reference samples by 40.8-41.4 %.

  10. Solid recovered fuels in the cement industry with special respect to hazardous waste.

    Science.gov (United States)

    Thomanetz, Erwin

    2012-04-01

    Cements with good technical properties have been produced in Europe since the nineteenth century and are now worldwide standardized high-quality mass products with enormous production numbers. The basic component for cement is the so-called clinker which is produced mainly from raw meal (limestone plus clay plus sands) in a rotary kiln with preheater and progressively with integrated calciner, at temperatures up to 1450 °C. This process requires large amounts of fossil fuels and is CO₂-intensive. But most CO₂ is released by lime decomposition during the burning process. In the 1980s the use of alternative fuels began--firstly in the form of used oil and waste tyres and then increasingly by pre-conditioned materials from commercial waste and from high calorific industrial waste (i.e. solid recovered fuel (SRF))--as well as organic hazardous waste materials such as solvents, pre-conditioned with sawdust. Therefore the cement industry is more and more a competitor in the waste-to-energy market--be it for municipal waste or for hazardous waste, especially concerning waste incineration, but also for other co-incineration plants. There are still no binding EU rules identifying which types of SRF or hazardous waste could be incinerated in cement kilns, but there are some well-made country-specific 'positive lists', for example in Switzerland and Austria. Thus, for proper planning in the cement industry as well as in the waste management field, waste disposal routes should be considered properly, in order to avoid surplus capacities on one side and shortage on the other.

  11. Development of LiCl-containing calcium aluminate cement for bone repair and remodeling applications.

    Science.gov (United States)

    Acuña-Gutiérrez, I O; Escobedo-Bocardo, J C; Almanza-Robles, J M; Cortés-Hernández, D A; Saldívar-Ramírez, M M G; Reséndiz-Hernández, P J; Zugasti-Cruz, A

    2017-01-01

    The effect of LiCl additions on the in vitro bioactivity, hemolysis, cytotoxicity, compressive strength and setting time of calcium aluminate cements was studied. Calcium aluminate clinker (AC) was obtained via solid state reaction from reagent grade chemicals of CaCO3 and Al2O3. Calcium aluminate cements (CAC) were prepared by mixing the clinker with water or aqueous LiCl solutions (0.01, 0.0125 or 0.015M (M)) using a w/c ratio of 0.4. After 21days of immersion in a simulated body fluid (SBF) at physiological conditions of temperature and pH, a Ca-P rich layer, identified as hydroxyapatite (HA), was formed on the cement without LiCl and on the cement prepared with 0.01M of LiCl solution. This indicates the high bioactivity of these cements. The cements setting times were significantly reduced using LiCl. The measured hemolysis percentages, all of them lower than 5%, indicated that the cements were not hemolytic. The compressive strength of the cements was not negatively affected by the LiCl additions. The obtained cement when a solution of LiCl 0.010M was added, presented high compressive strength, appropriated bioactivity, no cytotoxicity and low setting time, making this material a potentially bone cement.

  12. System of lower cogeneration in the cement industry; Sistema de cogeneracion inferior en la industria del cemento

    Energy Technology Data Exchange (ETDEWEB)

    Romero Paredes, H.; Vazquez, A; Ambriz, J. J.; Fosado, A.; Cedillo, D.; Sanchez, R. [Universidad Autonoma Metropolitana-Iztapalapa (Mexico)

    1999-07-01

    In this paper present work, the design of a cogeneration system was made, taking advantage of the waste thermal flows in a cement manufacturing industry. The costs by concept of energy sources in the cement industry represent between 30 and 60% of the production costs, reason why any diminution in its consumption, will be reflected considerably in the productivity of the company. In order to determine the available capacity of waste energy and to establish the dimension of the cogeneration system it was decided to initially conduct balances of matter and energy of a cement production train. For the evaluation and numerical simulation a case study of a national plant was taken. The analysis takes only into account the rotary kiln, the pre roaster, the gas cooler or conditioner, the cooler of clinker and the separators or dust recuperators. In this study the electrical mills nor the systems that operate all over the plant have been taken in consideration. The results show that in general a high potential of co-generation exists since in some cases the heat losses can reach up to a 50% of the calorific energy input. The capacity of electrical generation by means of a steam turbine when taking advantage of a fraction (in the order of 60%) the residual heat, can be between 200 and 300 watts per kilogram of clinker produced. In conclusion, when recovering by means of appropriate heat exchangers for each one of the mentioned equipment the wasted energy and a network of heat interchange optimized by means of modern technologies an important part of the electrical energy that a cement mill uses can be generated. The method used has been very attractive and with the possibility of applying it to any cement mill and thus evaluate the potentials of energy co-generation. [Spanish] En el presente trabajo, se realizo el diseno de un sistema de cogeneracion aprovechando las corrientes termicas de desecho en una industria de fabricacion de cemento. Los costos por concepto de

  13. 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.

  14. Air emission from the co-combustion of alternative derived fuels within cement plants: Gaseous pollutants.

    Science.gov (United States)

    Richards, Glen; Agranovski, Igor E

    2015-02-01

    Cement manufacturing is a resource- and energy-intensive industry, utilizing 9% of global industrial energy use while releasing more than 5% of global carbon dioxide (CO₂) emissions. With an increasing demand of production set to double by 2050, so too will be its carbon footprint. However, Australian cement plants have great potential for energy savings and emission reductions through the substitution of combustion fuels with a proportion of alternative derived fuels (ADFs), namely, fuels derived from wastes. This paper presents the environmental emissions monitoring of 10 cement batching plants while under baseline and ADF operating conditions, and an assessment of parameters influencing combustion. The experiential runs included the varied substitution rates of seven waste streams and the monitoring of seven target pollutants. The co-combustion tests of waste oil, wood chips, wood chips and plastic, waste solvents, and shredded tires were shown to have the minimal influence when compared to baseline runs, or had significantly reduced the unit mass emission factor of pollutants. With an increasing ADF% substitution, monitoring identified there to be no subsequent emission effects and that key process parameters contributing to contaminant suppression include (1) precalciner and kiln fuel firing rate and residence time; (2) preheater and precalciner gas and material temperature; (3) rotary kiln flame temperature; (4) fuel-air ratio and percentage of excess oxygen; and (5) the rate of meal feed and rate of clinker produced.

  15. Thermal monitoring at E-Sheng cement in China; Waermeueberwachung bei E-Sheng Cement in China

    Energy Technology Data Exchange (ETDEWEB)

    Idoux, Maurice [HGH Infrared Systems, Igny (France)

    2011-07-01

    The E-Sheng cement plant is situated 130 km South East of Chengdu, capital city of Sichuan Province. It is in an environmentally protected area and as such, it is subject to stringent regulations as far as pollution is concerned. The quarry is situated 5 km away on a hillside, 500 m above plant level. Transport of limestone is by one single conveyor. The plant has 5 identical kilns, each 5500 tpd, i.e. 27 500 tpd total output, making it the largest single plant in the southwest of China. The plant was designed by the Nanjing Cement Institute (NCDRI). Its specific heat consumption is 730 kcal/kg of clinker, 65% at the precalciner and 35% at the kiln. Each kiln is 4.8 m dia x 74 m long. Start-up fuel is oil, main fuel is coal, 5500 kcal/kg LHV. The coal mine is 25 km away; coal delivery to the plant is by road. The plant is checked regularly for emissions, management of the plant is particularly advanced and the staff is well trained, thus achieving at high quality product. The total number of employees is 3000. 15% of the production is sold in bags, the rest in bulk. Delivery to clients is by road or rail. The first line was commissioned in 2008, the last in 2010. Due to the 2008 earthquake 300 km away, local demand for cement remains high. Each kiln is equipped with a hig resolution scanner which warns the operator of any refractory lining/coating problems and possible malfunction of the kiln. (orig.)

  16. Optimization of Mineral Composition of High Belite-sulphoaluminate Clinker%高贝利特硫铝酸盐熟料矿物组成优化

    Institute of Scientific and Technical Information of China (English)

    李娟; 周春英; 杨亚晋

    2012-01-01

    The belite-calcium sulphoaluminate cement (BCSA) clinker with belite(C2S) of 35%-65%, calcium sulphoaluminate (C4A3S) of 20%-50%, and ferrite (CaAF) of 5%-15% was prepared with four major raw materials like limestone, bauxite, clay and gypsum. Two aspects on the preparation of BCSA clinker are (1) burnability of raw meal and (2) optimization of clinker phasesand gypsum content in cement. The results show that the cement with clinker burned during 1 280-1 320 ℃ containing C4A3S of 32%-42%, C4AF of 5%-9%, C2S of 46%-56% and gypsum of 12.5% can give the average mechanical strength of 55 MPa at 28 days. Compared to OPC, the BCSA cement consumes less energy and emits less emission.%采用石灰石、矾土、黏土和石膏 4 种原料,制备了以贝利特、无水硫铝酸钙和铁相为主的高贝利特无水硫铝酸盐水泥(BCSA)熟料矿物体系,研究了其生料易烧性、熟料煅烧制度和熟料矿物优化配比等。结果表明:当 BCSA 熟料煅烧温度为 1280~1320 ℃时,可获得结晶度良好、形成数量较多的贝利特和无水硫铝酸钙矿物。在 BCSA 熟料矿物组成为 32%~42% C4A3S—、5%~9% C4AF、46%~56% C2S,石膏掺量为 12.5%时,水泥 28 d抗压强度达最佳,为 55MPa。此外,由于熟料烧成温度及氧化钙总含量(约 50%)均较低,BCSA 水泥在能耗和排放方面均比普通硅酸盐水泥低。

  17. 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.

  18. Effect of carbon dioxide injection on production of wood cement composites from waste medium density fiberboard (MDF).

    Science.gov (United States)

    Qi, H; Cooper, P A; Wan, H

    2006-01-01

    The possibility of recycling waste medium density fiberboard (MDF) into wood-cement composites was evaluated. Both new fibers and recycled steam exploded MDF fibers had poor compatibility with cement if no treatment was applied, due to interference of the hydration process by the water soluble components of the fiber. However, this issue was resolved when a rapid hardening process with carbon dioxide injection was adopted. It appears that the rapid carbonation allowed the board to develop considerable strength before the adverse effects of the wood extractives could take effect. After 3-5 min of carbon dioxide injection, the composites reached 22-27% of total carbonation and developed 50-70% of their final (28-day) strength. Composites containing recycled MDF fibers had slightly lower splitting tensile strength and lower tensile toughness properties than those containing new fibers especially at a high fiber/cement ratio. Composites containing recycled MDF fibers also showed lower values of water absorption. Unlike composites cured conventionally, composites cured under CO(2) injection developed higher strength and toughness with increased fiber content. Incorporation of recycled MDF fibers into wood cement composites with CO(2) injection during the production stage presents a viable option for recycling of this difficult to manage waste material.

  19. Mineralogy and microstructure of two Mexican Portland cements for the confinement of radioactive waste; Mineralogia y microestructura de dos cementos mexicanos Portland para el confinamiento de desechos radiactivos

    Energy Technology Data Exchange (ETDEWEB)

    Galicia A, E. [Universidad Autonoma del Estado de Mexico, Facultad de Ciencias, Campus El Cerrillo, Piedras Blancas, Carretera Toluca-Ixtlahuaca Km. 15.5, Estado de Mexico (Mexico); Badillo A, V. E.; Ramirez S, J. R. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Nava E, N., E-mail: nasiega_181@hotmail.com [Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas No. 152, Col. San Bartolo Atepehuacan, 07730 Mexico D. F. (Mexico)

    2014-10-15

    The cementitious materials are involved in the different stages of radioactive waste management because they are used for the waste immobilization in the container, as well as filling in the spaces between containers vaults and also as engineering barrier and construction material in civil construction site. Therefore, is necessary to have a study of commercial cement available nationwide involving solid timely analysis in order to identify which phases are responsible for confinement of radionuclides, if considered the most reactive phase -CSH- or called secondary phases. In this research the hydration products of cement are presented as well as its importance in the nuclear industry. The analysis and observation of the cement clinker and the hydration products on the manufactured pulps with two commercial cements resistant to sulphates was realized using the observation technique of solid X-ray diffraction and nuclear analytic techniques of Moessbauer spectroscopy and X-Ray Fluorescence. The results show the presence of calcium silicate hydrates in the amorphous phase and the presence of ettringite crystals and portlandite sheets is appreciated. The abundant iron phase called tetra calcium ferro aluminate has been identified by Moessbauer spectroscopy. (Author)

  20. Characterization using thermomechanical and differential thermal analysis of the sinterization of Portland clinker doped with CaF{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez, O., E-mail: nanoquimica@yahoo.com [Fac. de Quimica-UASLP, Av. Dr. Salvador Nava 6, CP 78210, San Luis Potosi, SLP (Mexico); Torres-Castillo, A. [Fac. de Quimica-UASLP, Av. Dr. Salvador Nava 6, CP 78210, San Luis Potosi, SLP (Mexico); Flores-Velez, L.M. [Instituto de Metalurgia-UASLP, Sierra Leona 550, CP 78210, San Luis Potosi, SLP (Mexico); Torres, R. [Mexichem Fluor S.A., Eje 106 s/n CP 78395, San Luis Potosi, SLP (Mexico)

    2010-04-15

    In this work, the sintering process of Portland cement was studied by combining thermomechanical analysis (TMA) and differential thermal analysis (DTA), together with X-ray diffraction (XRD) and scanning electron microscopy (SEM). Thermal analysis results employing both techniques indicted that phase transformations appeared at lower temperatures when CaF{sub 2} was incorporated in the raw materials. Besides, it was observed at high temperature that in some phase transformations TMA conducts to better resolution compared with the DTA measurements. Furthermore, mechanical properties and X-ray diffraction patterns corroborate the TMA and DTA results, corroborating that the final amount of alite (Ca{sub 3}SiO{sub 5}) is higher when a certain amount of CaF{sub 2} was present during the clinkerization process.

  1. Lunar cement

    Science.gov (United States)

    Agosto, William N.

    1992-01-01

    With the exception of water, the major oxide constituents of terrestrial cements are present at all nine lunar sites from which samples have been returned. However, with the exception of relatively rare cristobalite, the lunar oxides are not present as individual phases but are combined in silicates and in mixed oxides. Lime (CaO) is most abundant on the Moon in the plagioclase (CaAl2Si2O8) of highland anorthosites. It may be possible to enrich the lime content of anorthite to levels like those of Portland cement by pyrolyzing it with lunar-derived phosphate. The phosphate consumed in such a reaction can be regenerated by reacting the phosphorus product with lunar augite pyroxenes at elevated temperatures. Other possible sources of lunar phosphate and other oxides are discussed.

  2. Evaluation of Life-Cycle Assessment Studies of Chinese Cement Production: Challenges and Opportunities

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Hongyou; Masanet, Eric; Price, Lynn

    2009-05-29

    The use of life-cycle assessment (LCA) to understand the embodied energy, environmental impacts, and potential energy-savings of manufactured products has become more widespread among researchers in recent years. This paper reviews recent LCA studies in the cement industry in China and in other countries and provides an assessment of the methodology used by the researchers compared to ISO LCA standards (ISO 14040:2006, ISO 14044:2006, and ISO/TR 14048:2002). We evaluate whether the authors provide information on the intended application, targeted audience, functional unit, system boundary, data sources, data quality assessment, data disaggregation and other elements, and draw conclusions regarding the level of adherence to ISO standards for the papers reviewed. We found that China researchers have gained much experience during last decade, but still have room for improvement in establishing boundaries, assessing data quality, identifying data sources, and explaining limitations. The paper concludes with a discussion of directions for future LCA research in China.

  3. Formation, release and control of dioxins in cement kilns.

    Science.gov (United States)

    Karstensen, Kåre Helge

    2008-01-01

    Co-processing of hazardous wastes in cement kilns have for decades been thought to cause increased emissions of PCDD/PCDFs--a perception that has been evaluated in this study. Hundreds of PCDD/PCDF measurements conducted by the cement industry and others in the last few years, on emissions and solid materials, as well as recent test burns with hazardous wastes in developing countries do not support this perception. Newer data has been compared with older literature data and shows in particular that many emission factors have to be reconsidered. Early emission factors for cement kilns co-processing hazardous waste, which are still used in inventories, are shown to be too high compared with actual measurements. Less than 10 years ago it was believed that the cement industry was the main contributor of PCDD/PCDFs to air; data collected in this study indicates however that the industry contributes with less than 1% of total emissions to air. The Stockholm Convention on POPs presently ratified by 144 parties, classifies cement kilns co-processing hazardous waste as a source category having the potential for comparatively high formation and release of PCDD/PCDFs. This classification is based on early investigations from the 1980s and 1990s where kilns co-processing hazardous waste had higher emissions compared to those that did not burn hazardous waste. However, the testing of these kilns was often done under worst case scenario conditions known to favour PCDD/PCDF formation. More than 2000 PCDD/PCDF cement kiln measurements have been evaluated in this study, representing most production technologies and waste feeding scenarios. They generally indicate that most modern cement kilns co-processing waste today can meet an emission level of 0.1ngI-TEQ/m(3), when well managed and operated. In these cases, proper and responsible use of waste including organic hazardous waste to replace parts of the fossil fuel does not seem to increase formation of PCDD/PCDFs. Modern preheater

  4. Building materials for a sustainable future – cement

    CSIR Research Space (South Africa)

    Mapiravana, Joseph

    2014-03-01

    Full Text Available /or content were compared against a fixed 1kg OPC/CEM I (91% clinker), at plant, using Eco-invent data version 2.1 unit process. Results of the simulation are shown in Table 2. 8 Table 2. Comparison of carbon footprints of simulated geopolymers against... Geopolymer cement (0.85kg blast furnace slag, 0.15kg sodium silicate, furnace liquor, 37% in H2O, , Eco-invent data version 2.1 unit process 3. 1kg Geopolymer Cement (0.85kg blast furnace slag, 0.075kg sodium silicate, furnace liquor, 37% in H2O, at plant...

  5. The influence of heavy metals on the polymorphs of dicalcium silicate in the belite-rich clinkers produced from electroplating sludge.

    Science.gov (United States)

    Chen, Ying-Liang; Shih, Pai-Haung; Chiang, Li-Choung; Chang, Yi-Kuo; Lu, Hsing-Cheng; Chang, Juu-En

    2009-10-15

    The purpose of this study is to utilize an electroplating sludge for belite-rich clinker production and to observe the influence of heavy metals on the polymorphs of dicalcium silicate (C(2)S). Belite-rich clinkers prepared with 0.5-2% of NiO, ZnO, CuO, and Cr(2)O(3) were used to investigate the individual effects of the heavy metals in question. The Reference Intensity Ratio (RIR) method was employed to determine the weight fractions of gamma-C(2)S and beta-C(2)S in the clinkers, and their microstructures were examined by the transmission electron microscopy (TEM). The results showed that nickel, zinc, and chromium have positive effects on beta-C(2)S stabilization (Cr(3+)>Ni(2+)>Zn(2+)), whereas copper has a negative effect. The addition of up to 10% electroplating sludge did not have any negative influence on the formation of C(2)S. It was observed that gamma-C(2)S decreased while beta-C(2)S increased with a rise in the addition of the electroplating sludge. Moreover, nickel and chromium mainly contributed to stabilizing beta-C(2)S in the belite-rich clinkers produced from the electroplating sludge.

  6. The use of mexican cements in the low and medium radioactive wastes confinement; La utilizacion de cementos mexicanos en el confinamiento de desechos radioactivos de bajo y medio nivel

    Energy Technology Data Exchange (ETDEWEB)

    Badillo A, V.E.; Almazan T, M.G.; Alonso V, G.; Palacios H, J.C. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico)

    2008-07-01

    Inside the relative mark to the radioactive waste confinement, minerals of great fixation capacity like clays, apatites and diverse oxides are studied as matrixes, components and/or additives of the active barriers that separate the barrier geologic and the nuclear wastes. In this case, the cements intervene in those different stages of the waste management, since its are used for the immobilization of radioactive waste in the container, for the production of containers as well as filler of the spaces among the containers of the vaults, and also as engineering barrier and construction material in the civil work. For the above mentioned, it is particularly useful to characterize the Portland cements with at least 97% of clinker, since they are most recommended for this type of applications. Presently investigation work is carried out a preliminary chemical characterization, based on the mineralogical composition, of the Portland Mexican cement. Results are shown by the X-ray Diffraction technique when immobilizing a rich solution in sulfates to 5%, using two Portland commercial cements APASCO and TOLTECA, without observing the significant appearance of new phases. The cements besides incorporating the chemical species in the breast of the matrix, are also present as barriers of civil engineering in the facilities located only some meters deep for the storage of radioactive waste of low and intermediate level, for that the study of the radionuclides fixation, in the cements is of supreme importance to evaluate the safety of a nuclear repository with the help of cements; the retention of the iodine-131 in a limited interval of pH in the commercial APASCO and TOLTECA it was studied, being observed a scarce retention of this homologous of fission products, what indicates the necessity to use additives to improve the retention properties of the Mexican commercial cements for some radionuclides. (Author)

  7. CONCRETE BASED ON MODIFIED DISPERSE CEMENT SYSTEM

    Directory of Open Access Journals (Sweden)

    D. V. Rudenko

    2016-08-01

    Full Text Available Purpose. The article considers definition of the bond types occurring in a modified cement concrete matrix, and the evaluation of the quality of these links in a non-uniform material to determine the geometrical and physical relationships between the structure and the cement matrix modifiers. Methodology. To achieve this purpose the studies covered the microstructure of dispersed modified concrete cement matrix, the structure formation mechanism of the modified cement concrete system of natural hardening; as well as identification of the methods of sound concrete strength assessment. Findings. The author proposed a model of the spatial structure of the concrete cement matrix, modified by particulate reinforcement crystal hydrates. The initial object of study is a set of volume elements (cells of the cement matrix and the system of the spatial distribution of reinforcing crystallohydrates in these volume elements. It is found that the most dangerous defects such as cracks in the concrete volume during hardening are formed as a result of internal stresses, mainly in the zone of cement matrix-filler contact or in the area bordering with the largest pores of the concrete. Originality. The result of the study is the defined mechanism of the process of formation of the initial strength and stiffness of the modified cement matrix due to the rapid growth of crystallohydrates in the space among the dispersed reinforcing modifier particles. Since the lack of space prevents from the free growth of crystals, the latter cross-penetrate, forming a dense structure, which contributes to the growth of strength. Practical value. Dispersed modifying cement matrix provides a durable concrete for special purposes with the design performance characteristics. The developed technology of dispersed cement system modification, the defined features of its structure formation mechanism and the use of congruence principle for the complex of technological impacts of physical

  8. 水泥生产窑外预分解系统中多重燃烧技术的探讨%On Multi - stage Combustion Technique in Precalcining Cement Clinker Production System

    Institute of Scientific and Technical Information of China (English)

    姚强

    2009-01-01

    在燃烧技术领域,多重燃烧技术主要是针对降低燃烧产物中NOx含量而兴起的.在水泥生产的窑外预分解系统中,该技术目前在国外已经获得了广泛的重视.该文针对该燃烧技术在预分解系统中使用的优点以及这个方面技术在国外水泥工业中的应用情况展开讨论,以期对于有关的设计与操作有所裨益.

  9. The production of sulphoaluminate cement clinker with phosphorus gypsum as raw material%磷石膏作原料试生产硫铝酸盐水泥熟料

    Institute of Scientific and Technical Information of China (English)

    李德栋; 毕利坤; 王晓华

    2002-01-01

    介绍了用磷石膏配料在回转窑上进行硫铝酸盐水泥试生产的情况.结果表明,用磷石膏配料,能改善生料的易磨性和易烧性,提高生、熟料的产量,并能改善熟料的凝结特性.根据磷石膏特点,在生产中需采取一些工艺措施,以使磷石膏得以充分利用.

  10. The use of electrical impedance spectroscopy for monitoring the hydration products of Portland cement mortars with high percentage of pozzolans

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, J.M. [Departamento de Física Aplicada, Universitat Politècnica de València, Camino de Vera, 46022, Valencia (Spain); Fita, I.C., E-mail: infifer@fis.upv.es [Departamento de Física Aplicada, Universitat Politècnica de València, Camino de Vera, 46022, Valencia (Spain); Soriano, L.; Payá, J.; Borrachero, M.V. [ICITECH, Instituto de Ciencia y Tecnología del Hormigón, Universitat Politècnica de València (Spain)

    2013-08-15

    In this paper, mortars and pastes containing large replacement of pozzolan were studied by mechanical strength, thermogravimetric analysis (TGA), scanning electronic microscopy (SEM), mercury intrusion porosimetry (MIP) and electrical impedance spectroscopy (EIS). The effect of metakaolin (35%) and fly ash (60%) was evaluated and compared with an inert mineral addition (andalusite). The portlandite content was measured, finding that the pozzolanic reaction produced cementing systems with all portlandite fixed. The EIS measurements were analyzed by the equivalent electrical circuit (EEC) method. An EEC with three branches in parallel was applied. The dc resistance was related to the degree of hydration and allowed us to characterize plain and blended mortars. A constant phase element (CPE) quantified the electrical properties of the hydration products located in the solid–solution interface and was useful to distinguish the role of inert and pozzolanic admixtures present in the cement matrix.

  11. Fundamental properties of industrial hybrid cement: utilization in ready-mixed concretes and shrinkage-reducing applications

    Directory of Open Access Journals (Sweden)

    Martauz, P.

    2016-06-01

    Full Text Available Utility properties of novel hybrid cement (H-Cement are influenced by pozzolanic reaction of fly ash, latent hydraulic reaction of metallurgical slag together with the alkali activation of inorganic geopolymer based on precipitated waste water coming from bauxite residues. Content of Portland cement clinker is at maximum of 20 mass %, the remaining portion consists of inorganic geopolymer. Up to 80% of CO2 emissions are saved by H-Cement manufacture compared to ordinary Portland cement (OPC. No heat treatment or autoclaving is needed at H-Cement production. The field application of H-Cement is performed by the same way than that of common cements listed in EN 197-1, and is also connected with highly efficient recovery and safe disposal of red mud waste. H-Cement is suitable for ready-mixed concretes up to C30/37 strength class and is specified by beneficial shrinkage-reducing property of the concrete kept in long dry-air cure opposite to common cements.Las propiedades de un nuevo cemento híbrido (cemento-H vienen determinadas por la reaccion puzolánica de cenizas volantes, la hidráulica latente de las escorias metalúrgicas y la activación alcalina mediante las aguas residuales generadas por el tratamiento de la bauxita para dar un geopolímero inorgánico. La proporción máxima de clínker de cemento en este nuevo material es del 20%, y por ello, en su fabricación se emite hasta un 80% menos de CO2 que en la producción del cemento portland (OPC. El cemento-H se prepara sin necesidad de tratamiento térmico ni de estancia en autoclave y su aplicación es la misma que los cementos convencionales definidos en la norma EN 197-1. Por otra parte, su fabricación supone la recuperación y la valorización segura de los lodos rojos de bauxita. El cemento-H es apto para la preparación de hormigones premezclados hasta la categoría C30/37, presentando el nuevo material, además, una menor retracción que los cementos convencionales, por lo que su

  12. Production of bone cement composites: effect of fillers, co-monomer and particles properties

    Energy Technology Data Exchange (ETDEWEB)

    Santos Junior, J.G.F.; Melo, P.A.; Pinto, J.C., E-mail: jjunior@peq.coppe.ufrj.b, E-mail: melo@peq.coppe.ufrj.b, E-mail: pinto@peq.coppe.ufrj.b [Coordenacao dos Programas de Pos-Graduacao de Engenharia. (PEQ/COPPE/UFRJ), RJ (Brazil). Programa de Engenharia Quimica; Pita, V.J.R.R., E-mail: vjpita@ima.ufrj.b [Universidade Federal do Rio de Janeiro (IMA/UFRJ), RJ (Brazil). Inst. de Macromoleculas Eloisa Mano; Nele, M. [Universidade Federal do Rio de Janeiro (EQ/UFRJ), RJ (Brazil). Escola de Quimica

    2011-04-15

    Artificial bone cements (BCs) based on poly(methyl methacrylate) (PMMA) powders and methyl methacrylate (MMA) liquid monomer also present in their formulation small amounts of other substances, including a chemical initiator compound and radiopaque agents. Because inadequate mixing of the recipe components during the manufacture of the bone cement may compromise the mechanical properties of the final pieces, new techniques to incorporate the fillers into the BC and their effect upon the mechanical properties of BC pieces were investigated in the present study. PMMA powder composites were produced in situ in the reaction vessel by addition of X-ray contrasts to the reacting MMA mixture. It is shown that this can lead to much better mechanical properties of test pieces, when compared to standard bone cement formulations, because enhanced dispersion of the radiopaque agents can be achieved. Moreover, it is shown that the addition of hydroxyapatite (HA) and acrylic acid (AA) to the bone cement recipe can be beneficial for the mechanical performance of the final material. It is also shown that particle morphology can exert a tremendous effect upon the performance of test pieces, indicating that the suspension polymerization step should be carefully controlled when optimization of the bone cement formulation is desired. (author)

  13. Characterization of U(VI)-phases in corroded cement products by micro(μ)-spectroscopic methods

    Science.gov (United States)

    Rothe, J.; Brendebach, B.; Bube, C.; Dardenne, K.; Denecke, M. A.; Kienzler, B.; Metz, V.; Prüßmann, T.; Rickers-Appel, K.; Schild, D.; Soballa, E.; Vitova, T.

    2013-04-01

    Cementation is an industrial scale conditioning method applied to fix and solidify liquid low and intermediate level radioactive wastes (LLW/ILW) prior to underground disposal in geological formations.To assist prognosis of the long-term safety of cemented waste, alteration of uranium doped cement productswas studied in chloride-rich solutions relevant for final LLW/ILW disposal in rock salt. After long-time exposure of the full-scale LLW/ILW simulates to concentrated NaCl and MgCl2 brines, solid samples were retrieved for chemical and mineralogical analysis with an emphasis on uranium speciation in the corroded cement matrix.Bulk and recent spatially resolved micro(μ) U L3-XAFS measurements point to the occurrence of a diuranate type U(VI) phase forming throughout the corroded cement monoliths. U-enriched hot spots with dimensions up to several tens of μm turn out to be generally X-ray amorphous.

  14. Studies on the Potential of Waste Soda Lime Silica Glass in Glass Ionomer Cement Production

    Directory of Open Access Journals (Sweden)

    V. W. Francis Thoo

    2013-01-01

    Full Text Available Glass ionomer cements (GIC are produced through acid base reaction between calcium-fluoroaluminosilicate glass powder and polyacrylic acid (PAA. Soda lime silica glasses (SLS, mainly composed of silica (SiO2, have been utilized in this study as the source of SiO2 for synthesis of Ca-fluoroaluminosilicate glass. Therefore, the main objective of this study was to investigate the potential of SLS waste glass in producing GIC. Two glasses, GWX 1 (analytical grade SiO2 and GWX 2 (replacing SiO2 with waste SLS, were synthesized and then characterized using X-ray diffraction (XRD and energy dispersive X-ray (EDX. Synthesized glasses were then used to produce GIC, in which the properties were characterized using Fourier transform infrared spectroscopy (FT-IR and compressive test (from 1 to 28 days. XRD results showed that amorphous glass was produced by using SLS waste glass (GWX 2, which is similar to glass produced using analytical grade SiO2 (GWX 1. Results from FT-IR showed that the setting reaction of GWX 2 cements is slower compared to cement GWX 1. Compressive strengths for GWX 1 cements reached up to 76 MPa at 28 days, whereas GWX 2 cements showed a slightly higher value, which is 80 MPa.

  15. Effect of Slag on Burnability Cement Raw Meal Containing Silica Crystals%矿渣对煅烧含高结晶态SiO2水泥生料的影响

    Institute of Scientific and Technical Information of China (English)

    艾红梅; 卢普光; 白军营; 卢洪正

    2012-01-01

    The burnability of raw materials and the quality of clinkers can be affected while too much quartz in raw material. Quartz will be brought in raw materials inevitably while the all components of waste concrete were used in cement production. Different proportions of slag were mixed in raw material in the experiment, the effect of slag on the clinker property and the burnability of raw material whose silicon materials were ISO standard sand was studied. The ethanol-glycol method was used to analyze the content of f-CaO, clinker minerals were identified by XRD, mineral morphology was observed by metalloscope, cement paste specimen were produced to test the compressive strength of hydrated clinker. The result showed that the burnability of raw materials with high quartz content was notably improved while adding the slag, slag also improved the formation of clinker mineral, while the amount of slag in raw materials was 3% ,hydrated clinker has the highest comprehensive strength; clinker produced more C-S-H gel and AFt in early hydration and C-S-H gel can be much denser in late hydration while moderate slag added in the raw materials.%利用含砂废弃混凝土原料煅烧水泥熟料,不可避免地会由细骨料砂引入结晶度较高的结晶态SiO2,不仅影响生料易烧性,而且影响硅酸盐矿物的组成和形貌,降低熟料质量.以ISO标准砂为硅质原料配制高结晶态SiO2含量的生料,按不同比例掺入矿渣,煅烧至不同温度;利用化学分析、XRD、岩相分析、SEM等方法,研究矿渣对水泥生料易烧性、熟料矿物组成和显微结构、熟料水化强度发展及水化产物形貌的影响.结果表明,适量矿渣的掺入可显著改善高结晶态SiO2含量水泥生料的易烧性,促进熟料矿物形成和发育;矿渣掺量为3%时,熟料水化后强度最高;适量矿渣可使熟料水化早期产生较多的C-S-H凝胶和钙矾石,而后期水化产物中C-S-H凝胶更密实,提高水泥强度.

  16. Comparison of Domestic and International Calculation Methods of CO2 Emission from Cement Production and the Enlightenments for China%水泥生产碳排放测算的国内外方法比较及借鉴

    Institute of Scientific and Technical Information of China (English)

    魏丹青; 赵建安; 金迁致

    2012-01-01

    The comparison of domestic and international calculation methods of CO2 emission from cement production has important reference value for establishing national calculation standards of CO2 emission from cement production.At present,international organizations like Intergovernmental Panel on Climate Change(IPCC)and World Business Council for Sustainable Development(WDCSD)have promulgated a series of universally applicable methods,and a number of developed countries have also proposed their own calculation systems.In this paper,we first briefly introduced the domestic and international calculation methods of CO2 emission from cement production,and performed a comparison of these methods from four aspects,including operational boundaries,raw material calcination emissions,fuel combustion emissions and indirect emissions.Then we made a discussion about the accuracy and applicability of those methods.The conclusions are as follows:1)Those systems are approximately same in the framework of calculation process,but there are differences in operational boundaries,calculating methods and CO2 emission factors;2)WBCSD-Cement Sustainability Initiative provides the methods of setting operational boundaries for countries or enterprises to choose the scope of accounting and reporting;3)On plant level,calcination CO2 can be calculated in two ways:based on the quantity and composition of the raw mix consumed or based on the clinker produced plus discarded dust.The two approaches are,in theory,equivalent.On country level,the latter approach is usually adopted;4)CO2 from fossil kiln fuels(coal,fuel oil and natural gas)is calculated based on fuel consumption,net calorific values,and CO2 emission factors.For China,low calorific value is applicable;5)On country level,the emissions of external production of electricity consumption should be included in the gross emissions,while indirect emission savings such as heat and power exports should be subtracted from the

  17. Rietveld full-profile quantification of Portland cement: the importance of including full crystallography of the phase polymorphs

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, J.C.; Matulis, C.E [Commonwealth Scientific and Industrial Research Organization, Lucas Heights, NSW (Australia); Hinczak, I. [James Hardie Research Laboratories, Granville, NSW (Australia)

    1999-12-01

    Full text: Previous Rietveld quantifications of Portland cement clinkers used a fixed structural model for alite, the major clinker phase with a C{sub 3}S-type structure. From Rietveld quantification studies using the SlROQUANT{sup tm} program on XRD powder patterns of the three NIST SRM standard clinkers 8486, 8487, and 8488 (CoK{alpha}), it is shown that best results here are obtained using three C{sub 3}S models, one from each of the three crystal systems found in alite polymorphs. It is necessary to specify the phase crystallography well, owing to the extreme superposition of alite and belite XRD lines. Unsatisfactory results can sometimes occur when only one or two of these C{sub 3}S polymorphs are used in the Rietveld quantifications. Polymorphism in belite (clinker C{sub 2}S-type phase) and C{sub 3}A(aluminate phase), is also included. The Rietveld full-profile XRD method is shown to be as powerful in quantifying phases in Portland cement clinker as the microscope point-counting(MPC) method. The Rietveld method can in addition, discriminate between phase polymorphs, and is far less labour-intensive than MPC. Rietveld and MPC methods give the same results for the three NIST standard clinkers. The Rietveld oxide weight percentages, obtained from the Rietveld phase weight percentages by a reverse-Bogue calculation, assuming the average chemical compositions of the clinker phases of Taylor(1990), agree well with the XRF oxide percentages. The MPC method also agrees equally as well with XRF oxide percentages as the Rietveld method. Bogue weight percentages do not agree with Rietveld or MPC figures. Transformation of the Bogue percentages by the reverse-Bogue program to oxides does not give as good a comparison with XRF as does either the Rietveld or MPC method. Copyright (1999) Australian X-ray Analytical Association Inc.

  18. 77 FR 5573 - Notice Pursuant to the National Cooperative Research and Production Act of 1993-Portland Cement...

    Science.gov (United States)

    2012-02-03

    ... Cement Association Notice is hereby given that, on January 6, 2012, pursuant to Section 6(a) of the... Cement Association (``PCA'') has filed written notifications simultaneously with the Attorney General and... this venture. Also, Texas-Lehigh Cement Company, Buda, TX; Arizona Cement Association, Phoenix,...

  19. 76 FR 12370 - Notice Pursuant to the National Cooperative Research and Production Act of 1993-Portland Cement...

    Science.gov (United States)

    2011-03-07

    ... Cement Association Notice is hereby given that, on February 02, 2011, pursuant to Section 6(a) of the... Cement Association (``PCA'') has filed written notifications simultaneously with the Attorney General and..., PA; Lehigh Cement Company LLC, Allentown, PA; Lehigh Northwest Cement Company, Seattle, WA;...

  20. Chemically bonded cements formulated with by-products of magnesium oxide

    OpenAIRE

    2008-01-01

    The casting of magnesium and potassium phosphate (KMgPO4•6H2O; K-struvite) cements becomes possible after the aqueous reaction between magnesium oxide and potassium dihydrogen phosphate. This reaction is quite exothermic and allows the resulting paste setting in just few minutes. Those cements, when are cast with magnesium oxides of high purity, are used to retain and encapsulate special residues and as repairing concrete mortar, as it is described in the bibliography. However, it is also pos...

  1. INFLUENCE OF WATER-TO-CEMENT RATIO ON AIR ENTRAILMENT IN PRODUCTION OF NON-AUTOCLAVED FOAM CONCRETE USING TURBULENCE CAVITATION TECHNOLOGY

    Directory of Open Access Journals (Sweden)

    Gorshkov Pavel Vladimirovich

    2012-10-01

    Full Text Available Non-autoclaved foam concrete is an advanced thermal insulation material. Until recently, foam concrete production has been based on separate preparation of foam and solution, followed by their blending in a mixer. The situation changed when high-quality synthetic foaming agents and turbulence cavitation technology appeared on the market. Every model provides a dependence between the foam concrete strength and the water-to-cement ratio. According to the water-cement ratio we can distinguish strong concrete mixtures (with the water-to-cement ratio equal to 0.3…0.4 and ductile ones (with the water-to-cement ratio equal to 0.5…0.7. Strong concrete mixtures are more durable. The lower the water-to-cement ratio, the higher the foam concrete strength. However super-plastic substances cannot be mixed by ordinary turbulent mixers. Foam concrete produced using the turbulence cavitation technology needs air-entraining, its intensity being dependent on several factors. One of the main factors is the amount of free water, if it is insufficient, the mixture will not be porous enough. A researcher needs to identify the optimal water-to-cement ratio based on the water consumption rate. Practical production of prefabricated concrete products and structures has proven that the reduction of the water-to-cement ratio improves the strength of the product. The task is to find the water-to-cement ratio for the foam concrete mixture to be plastic enough for air entraining. An increase in the ratio causes loss in the strength. The ratio shall vary within one hundredth points. Super-plasticizers are an alternative solution.

  2. Investigation and control measures of occupational hazards in grinding station of a cement enterprise of Aoxi%奥西某水泥公司粉磨站职业病危害调查及控制措施

    Institute of Scientific and Technical Information of China (English)

    卢建国; 朱春兰; 陈枨光

    2013-01-01

    目的 调查奥西某水泥公司水泥粉磨站的工艺特点、职业病危害因素的种类及浓(强)度,提出相应的控制措施.方法 对水泥粉磨站的工艺流程、职业病危害因素种类及现场检测的资料进行收集、整理与分析.结果 该水泥粉磨站工艺特点为采用新技术设备.职业病危害因素主要是粉尘(水泥尘、矽尘、石灰石粉尘、石膏粉尘和熟料尘)和噪声2类.粉尘时间加权平均(TWA)浓度范围0.3~44.4 mg/m3,超标率53.3%;短时间接触浓度(STEL)范围0.3~68.0 mg/m3,超标率19.0%.水泥粉尘浓度超标38.9%~58.3%,熟料尘浓度超标11.1%~33.3%,矽尘、石灰石粉尘和石膏粉尘浓度均在国家职业卫生限值范围内.作业岗位的个体噪声强度为78.9~ 86.4 dB(A),超标率为16.7%.结论 该项目职业病危害因素为水泥粉尘、熟料粉尘和噪声.对此提出了职业病危害预防控制措施和管理措施,以保护劳动者身体健康.%[Objective]To investigate the process characteristics, species and exposure levels of occupational hazards in grinding station of a cement enterprise of Aoxi, and put forward related control measures. [ Methods] The production process, species of occupational hazards and field detection data in the cement grinding station were collected and analyzed. [Results] The cement grinding station technology was characterized by adopting new technology and equipment. Noise and dust (cement dust, silica dust, limestone dust, gypsum dust and clinker dust) were primary occupational hazards. Dust TWA ranged from 0.3-44.4 mg/m3, with over standard rate of 53.3% ; The STEL ranged from 0.3-68.0 mg/m3, with over standard rate of 19.0%. Cement dust concentrations exceeded the standard from 38.9%-58. 3% ; clinker dust concentrations exceeded the standard from 11. 1%-33. 3% ; silica dust, limestone dust and plaster dust concentration were within the national occupation health limits. The individual noise

  3. Recovery Act Production of Algal BioCrude Oil from Cement Plant Carbon Dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Robert Weber; Norman Whitton

    2010-09-30

    The consortium, led by Sunrise Ridge Algae Inc, completed financial, legal, siting, engineering and environmental permitting preparations for a proposed demonstration project that would capture stack gas from an operating cement plant and convert the carbon dioxide to beneficial use as a liquid crude petroleum substitute and a coal substitute, using algae grown in a closed system, then harvested and converted using catalyzed pyrolysis.

  4. Assessment of radiological hazards of naturally occurring radioactive materials in cement industry.

    Science.gov (United States)

    Aslam, Muhammad; Gul, Rahmat; Ara, Tauseef; Hussain, Manzur

    2012-09-01

    A study on the radiological hazard in Portland cement due to the presence of naturally occurring radioactive materials is being carried out. The Portland cement manufactured in the Islamabad/Rawalpindi region of Pakistan, intermediate products (clinker) and the various raw materials which compose the product have been analysed for (226)Ra, (232)Th and (40)K using a gamma spectrometry system with a N-type high-purity germanium detector of 80 % relative efficiency. From the measured gamma ray spectra, specific activities were determined. The mean values of the total specific activity of (226)Ra, (232)Th and (40)K are 34.2±11.9, 29.1±3.6 and 295.1±66.9 Bq kg(-1), respectively in Portland cement, 28.4±8.7, 11.3±1.7 and 63.1±17.3 Bq kg(-1), respectively in lime stone, 8.2±1.9, 16.2±3.9 and 187.7±53.2 Bq kg(-1), respectively in gypsum, 34.7±13.1, 41.2±6.7 and 187.6±17.2 Bq kg(-1), respectively in clay, 41.1±11.8, 39.3±6.9 and 195.1±29.2 Bq kg(-1), respectively in latrite and 51.1±18.2, 23.2±1.2 and 258.4±15.3 Bq kg(-1), respectively in clinker. The radium equivalent activities (Ra(eq)), external hazard index (H(ex)), internal hazard index (H(in)), absorbed dose rate in air (D) and annual effective dose rate (E(eff)) were also determined. The measured activity concentrations for these radio nuclides and radiological indices were compared with the reported national and international data. All these measured values are comparable with the worldwide data reported in UNSCEAR publications.

  5. Principles of technological design of wasteless chemical processes based on the use of wastes for production of alkaline slag cements and concretes

    Energy Technology Data Exchange (ETDEWEB)

    Glukhovskii, V.D.; Chernobaev, I.P.; Emel' yanov, B.M.; Semenyuk, A.P.

    1985-05-20

    The strength characteristics of alkaline slag-cement made with the use of waste from alkaline sealing of metals are presented. The cement was prepared from granulated blast-furnance slag with average component contents in the following ranges (mass %): SiO/sub 2/ 36.0-40.2, Al/sub 2/O/sub 3/ 4-18.2, FeO 0.1-3.7, MnO 0.4-5.2, CaO 33.1-48.8, MgO 2.2-9.8. With the use of wastes from the descaling process in alkali melts for production of alkaline slag cements it is possible to obtain highly effective cements of type 700-900, which is 2 to 3 times the value for portland cements. Therefore, the use of wastes from alkaline descaling for production of alkaline slag cements is of great economic and conservational significance. It is possible to devise a wasteless process of scale removal from metals; this is an important advantage of the alkaline scaling method over acid pickling.

  6. Life cycle assessment of the use of alternative fuels in cement kilns: A case study.

    Science.gov (United States)

    Georgiopoulou, Martha; Lyberatos, Gerasimos

    2017-07-14

    The benefits of using alternative fuels (AFs) in the cement industry include reduction of the use of non-renewable fossil fuels and lower emissions of greenhouse gases, since fossil fuels are replaced with materials that would otherwise be degraded or incinerated with corresponding emissions and final residues. Furthermore, the use of alternative fuels maximizes the recovery of energy. Seven different scenaria were developed for the production of 1 ton of clinker in a rotary cement kiln. Each of these scenaria includes the use of alternative fuels such as RDF (Refuse derived fuel), TDF (Tire derived fuel) and BS (Biological sludge) or a mixture of them, in partial replacement of conventional fuels such as coal and pet coke. The purpose of this study is to evaluate the environmental impacts of the use of alternative fuels in relation to conventional fuels in the kiln operation. The Life Cycle Assessment (LCA) methodology is used to quantify the potential environmental impacts in each scenario. The interpretation of the results provides the conclusion that the most environmentally friendly prospect is the scenario based on RDF while the less preferable scenario is the scenario based on BS. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Influence of Blended Cements with Calcareous Fly Ash on Chloride Ion Migration and Carbonation Resistance of Concrete for Durable Structures

    Directory of Open Access Journals (Sweden)

    Michał A. Glinicki

    2016-01-01

    Full Text Available The objective of this paper is to examine the possible use of new blended cements containing calcareous fly ash in structural concrete, potentially adequate for structural elements of nuclear power plants. The investigation included five new cements made with different contents of non-clinker constituents: calcareous fly ash, siliceous fly ash, ground granulated blastfurnace slag, and a reference cement—ordinary Portland cement. The influence of innovative cements on the resistance of concrete to chloride and carbonation exposure was studied. Additionally, an evaluation of the microstructure was performed using optical microscopy on concrete thin sections. Test results revealed a substantial improvement of the resistance to chloride ion penetration into concrete containing blended cements. The resistance was higher for increased clinker replacement levels and increased with curing time. However, concrete made with blended cements exhibited higher depth of carbonation than the Portland cement concrete, except the Portland-fly ash cement with 14.3% of calcareous fly ash. The thin sections analysis confirmed the values of the carbonation depth obtained from the phenolphthalein test. Test results indicate the possible range of application for new cements containing calcareous fly ash.

  8. EFFECT OF WASTE MINERAL ADDITIVES ON FLOW STABILITY OVER TIME IN SELF-COMPACTING CONCRETE MIXES WITH LOW CLINKER CONTENT

    Directory of Open Access Journals (Sweden)

    Anna M. Grabiec

    2015-09-01

    Full Text Available Contemporary solutions in concrete technology are varied, and consist in e.g. the use of new generation concretes, including the most spectacular achievement of the 1990s – self-compacting concrete (SCC being the subject of continuous research, as well as protection of the environment against excessive anthropogenic pressures, such as carbon dioxide which is a major emission substance from the cement industry. The studies analysed the possibilities for replacing part of the clinker binder (cement CEM I 42.5 R in self-compacting concrete with three types of waste mineral additives: fly ash, limestone powder, and granite powder. Focus was placed on key technological characteristics of concrete mixes: air content and rheological properties, maximal diameter of slump-flow and changes thereof over time, as well as the mix’s flow time into the 500 mm diameter, determining the flow dynamics. 28-day compressive strength of the concrete was recognised as a secondary property which in self-compacting concretes results from achieving the right range of the mix’s rheological properties. Concretes were produced using gravel-sand aggregate in 3-fraction composition and a high-efficiency superplasticiser. The studies were conducted as a planned experiment in the 3-ingredient mixes plan.

  9. EFFECT OF MgO ON THE COMPOSITION AND PROPERTIES OF BELITE-BARIUM CALCIUM SULPHOALUMINATE CEMENT IN THE PRESENCE OF Na2O AND K2O

    Directory of Open Access Journals (Sweden)

    Jie Zhang

    2015-06-01

    Full Text Available The purpose of this study is to explore the effect of MgO (1 - 9 wt. % on the composition and properties of belite-barium calcium sulphoaluminate cement with additions of Na2O and K2O. The results show that 1 - 5 wt. % content of MgO can stabilize crystal types of M3-C3S, R-C3S and β-C2S. Moreover, MgO can promote the formation of C3S and C4AF, but has little effect on the formation of C2.75B1.25A3$ and C3A. The C3A/C4AF ratio is reduced by 22 % at 5 wt. % MgO, which indicates that appropriate MgO can decrease the liquid viscosity. In the presence of Na2O and K2O, the highest limit of incorporated amount of MgO is about 3 wt. %, which is higher than that in Portland cement clinker of 2 wt. %. Besides, MgO favors the formation of small C3S crystals in size of 4 - 20 μm. MgO enhances the hydration rate and mechanical property of cement at an optimal dosage (1 - 5 wt. %, beyond which an adverse effect could be resulted. At a MgO dosage of 5 wt. %, the compressive strengths of the cement at 1, 3, 7 and 28 days are 15.8, 39.3, 68.6 and 97.3 MPa, which increases by 116 %, 17 %, 10 % and 6 % respectively compared to the cement without MgO dopant. This study could lead to the effective use of magnesia-rich limestone in industrial production of belite-barium calcium sulphoaluminate cement.

  10. Paste strength and hydrates morphology of phosphoaluminate cement%磷铝酸盐胶凝材料的净浆强度与水化形貌

    Institute of Scientific and Technical Information of China (English)

    丁铸; 王晓东; 张宁; 刘飚

    2015-01-01

    Phosphoaluminate cement ( PAC ) clinker was prepared in laboratory. The mineral composition of PAC clinker was analyzed, and the compressive strength of hardened PAC clinker paste from 1 d to 90 d was measured and the hydrates morphology of PAC was also analyzed. The results show that the minerals in PAC clinker are calcium phosphoaluminate, calcium aluminate, α-tricalcium phosphate and glass phase. PAC can gain very high compressive strength in 7 day hydration, but the strength increasess lowly subsequently. According to the microcosmic analysis of the hydration products, different minerals have different hydration rates. The hydration products consist of hydrated calcium aluminate, CaO-Al2 O3-H2 O gel ( C-A-H gel) , and CaO-Al2 O3-P2 O5-H2 O gel ( C-A-P-H gel) . The atomic number ratios of Al to Ca in various forms of C-A-H gel are different.%在实验室制备出磷铝酸盐水泥熟料,并用微观测试技术测定其矿物组成,研究了其抗压强度在水化1~90 d的发展,分析了其水化产物的形貌和元素分布。研究结果表明,所制得的熟料所含的矿物为磷铝酸钙、铝酸一钙、α-磷酸三钙以及玻璃相。该材料的净浆具有非常高的早期抗压强度,强度能够持续增长。7d之前强度发展迅速,之后则发展较为平缓。根据对其水化产物的微观分析,发现熟料中不同矿物的水化活性不同,其水化速度相差较大。水化产物中主要含有水化铝酸钙,CaO-Al2 O3-H2 O凝胶( C-A-H凝胶)、CaO-Al2 O3-P2 O5-H2 O凝胶( C-A-P-H凝胶),各种形态的C-A-H凝胶中Al元素和Ca元素的原子数比例不同。

  11. Synthesis of active Belite-Alite-Ye'elimite clinker (BAY)

    OpenAIRE

    Zea-Garcia, Jesus D.; Aranda, M. A. G.; De la Torre, Angeles G.; Santacruz, I.

    2016-01-01

    Ordinary Portland cement (OPC) is an environmentally contentious material, as for every ton of OPC produced, on average, 0.97 tons of CO2 are released. Ye'elimite-rich cements are considered as eco-cements because their manufacturing process releases less CO2 into the atmosphere than OPC; this is due to the low calcite demand. Belite-Alite-Ye’elimite (BAY) cements are promising eco-friendly building materials as OPC substitutes at a large scale. The reaction of alite and ye´elimite with water...

  12. Characterization and utilization of cement kiln dusts (CKDs) as partial replacements of Portland cement

    Science.gov (United States)

    Khanna, Om Shervan

    The characteristics of cement kiln dusts (CKDs) and their effects as partial replacement of Portland Cement (PC) were studied in this research program. The cement industry is currently under pressure to reduce greenhouse gas (GHG) emissions and solid by-products in the form of CKDs. The use of CKDs in concrete has the potential to substantially reduce the environmental impact of their disposal and create significant cost and energy savings to the cement industry. Studies have shown that CKDs can be used as a partial substitute of PC in a range of 5--15%, by mass. Although the use of CKDs is promising, there is very little understanding of their effects in CKD-PC blends. Previous studies provide variable and often conflicting results. The reasons for the inconsistent results are not obvious due to a lack of material characterization data. The characteristics of a CKD must be well-defined in order to understand its potential impact in concrete. The materials used in this study were two different types of PC (normal and moderate sulfate resistant) and seven CKDs. The CKDs used in this study were selected to provide a representation of those available in North America from the three major types of cement manufacturing processes: wet, long-dry, and preheater/precalciner. The CKDs have a wide range of chemical and physical composition based on different raw material sources and technologies. Two fillers (limestone powder and quartz powder) were also used to compare their effects to that of CKDs at an equivalent replacement of PC. The first objective of this study was to conduct a comprehensive composition analysis of CKDs and compare their characteristics to PC. CKDs are unique materials that must be analyzed differently from PC for accurate chemical and physical analysis. The present study identifies the chemical and physical analytical methods that should be used for CKDs. The study also introduced a method to quantify the relative abundance of the different

  13. Magnetic properties and element concentrations in lichens exposed to airborne pollutants released during cement production.

    Science.gov (United States)

    Paoli, Luca; Winkler, Aldo; Guttová, Anna; Sagnotti, Leonardo; Grassi, Alice; Lackovičová, Anna; Senko, Dušan; Loppi, Stefano

    2017-05-01

    The content of selected elements (Al, As, Ca, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, S, Ti, V and Zn) was measured in samples of the lichen Evernia prunastri exposed for 30, 90 and 180 days around a cement mill, limestone and basalt quarries and urban and agricultural areas in SW Slovakia. Lichens transplanted around the investigated quarries and the cement mill rapidly (30 days) reflected the deposition of dust-associated elements, namely Ca (at the cement mill and the limestone quarry) and Fe, Ti and V (around the cement mill and the basalt quarry), and their content remained significantly higher throughout the whole period (30-180 days) with respect to the surrounding environment. Airborne pollutants (such as S) progressively increased in the study area from 30 to 180 days. The magnetic properties of lichen transplants exposed for 180 days have been characterized and compared with those of native lichens (Xanthoria parietina) and neighbouring bark, soil and rock samples, in order to test the suitability of native and transplanted samples as air pollution magnetic biomonitors. The magnetic mineralogy was homogeneous in all samples, with the exception of the samples from the basalt quarry. The transplants showed excellent correlations between the saturation remanent magnetization (Mrs) and the content of Fe. Native samples had a similar magnetic signature, but the values of the concentration-dependent magnetic parameters were up to two orders of magnitude higher, reflecting higher concentrations of magnetic particles. The concentrations of As, Ca and Cr in lichens correlated with Mrs values after neglecting the samples from the basalt quarry, which showed distinct magnetic properties, suggesting the cement mill as a likely source. Conversely, Ti and Mn were mostly (but not exclusively) associated with dust from the basalt quarry. It is suggested that the natural geological characteristics of the substrate may strongly affect the magnetic properties of lichen thalli

  14. Cement and concrete

    Science.gov (United States)

    Corley, Gene; Haskin, Larry A.

    1992-01-01

    To produce lunar cement, high-temperature processing will be required. It may be possible to make calcium-rich silicate and aluminate for cement by solar heating of lunar pyroxene and feldspar, or chemical treatment may be required to enrich the calcium and aluminum in lunar soil. The effects of magnesium and ferrous iron present in the starting materials and products would need to be evaluated. So would the problems of grinding to produce cement, mixing, forming in vacuo and low gravity, and minimizing water loss.

  15. 75 FR 4423 - Notice Pursuant to the National Cooperative Research and Production Act of 1993-Portland Cement...

    Science.gov (United States)

    2010-01-27

    ... Cement Association Notice is hereby given that, on December 14, 2009, pursuant to Section 6(a) of the... Cement Association (``PCA'') has filed written notifications simultaneously with the Attorney General and... damages under specified circumstances. Specifically, Continental Cement, Hannibal, MO has been added as...

  16. Sulfate specifications as a constraint to gypsum addition to cement and possible replacement of gypsum as an additive. Quarterly technical progress report, June-August 1979

    Energy Technology Data Exchange (ETDEWEB)

    Kantro, D.L.

    1979-10-01

    Potential alternatives to gypsum for controlling set in commercial cement, additives to deter sulfate-induced expansion, and the influence of clinker manufacture on expansion potential in cements were studied. If limitations on sulfate content were less restrictive, it would be possible to use kiln fuels with higher sulfur contents, and to employ energy efficient preheater kiln technology without risk of exceeding sulfate specifications. (FS)

  17. Constituent phases and mechanical properties of iron oxide-additioned phosphoaluminate cement

    Directory of Open Access Journals (Sweden)

    Yang, Shuai

    2015-06-01

    Full Text Available Iron oxide was added to phosphoaluminate clinker and its effects on cement constituents were determined using XRD, DSC, SEM-EDS and conduction calorimetry analysis. The variations in compressive strength were also studied. The results showed that in moderate amounts, iron oxide acts as a mineraliser during clinker sintering, furthering the conversion of CA1-Y(PY to LHss at a lower temperature than normally required for that reaction. The main constituents of iron oxide-rich phosphoaluminate clinker included LHss, CA1-Y(PY, CP1-Z(AZ and ferrite. The EDS findings showed that the composition of the ferrite phase was nonuniform. The conclusion drawn was that by modifying the dose of Fe2O3 , the composition of phosphoaluminate cement can be controlled to produce clinker and cement compliant with different mechanical strength requirements. The conduction calorimetry findings were consistent with those results.Este trabajo estudia, mediante DRX DSC, SEM-EDS y calorimetría de conducción, el efecto de la adición de óxido de hierro a un clinker de fosfoaluminato, así como las variaciones sufridas en su resistencia a compresión. Los resultados mostraron que en cantidades moderadas, el óxido de hierro actúa como mineralizador durante la sinterización del clinker, promoviendo la conversión de CA1-Y(PY a LHss a una temperatura más baja de la normalmente requerida. Los componentes principales del clínker de fosfoaluminato con óxido de hierrop son LHss, CA1-Y(PY, CP1-Z(AZ y fase ferritica. Los resultados de EDS mostraron que la composición de esta fase ferrítica no era uniforme. DE este estudio se ha podido concluir que variando la dosificación del Fe2O3 , se puede controlar la composición del fosfoaluminato para producir clinker y cemento compatibles con diferentes requisitos de resistencia mecánica. Los resultados de calorimetría de conducción fueron consistentes con los resultados.

  18. Composite Control of Precalciner Exit Temperature in Cement Rotary Kiln

    Institute of Scientific and Technical Information of China (English)

    赵晨; 诸静

    2003-01-01

    A composite control strategy for the precalciner exit temperature in cement kiln is introduced based on a mathematical model. In this model, the raw meal flow, coal powder flow and wind flow are taken as three input variables, the clinker fow and exit teperature of cement kiln are output variables, and other influencing factors are considered as disturbance. A composite control system is synthesied by integrating self-learning PID, fuzzy and feedforward function into a combined controller, and the arithmetics for the self-learning PID controller, fuzzy controller and feedforward controller are elaborated respectively. The control strategy has been realized by software in real practice at cement factory. Application results show that the composite control technology is superior to the general PID control in control effect, and is suitable to the industrial process control with slow parameter variation, nonlinearity and uncertainty.

  19. Natural γ-ray-emitting radionuclides in Egyptian cement

    Institute of Scientific and Technical Information of China (English)

    A.M.EL-ARABI; A.ABBADY; A.H. EL-KAMEL; A. NOSIER; A. MOUSTAFA

    2005-01-01

    Samples of cement manufactured in Egypt and the raw materials have been analyzed using gamma-spectroscopy, in order to determine the concentration of natural radionuclides and associated radiological hazard. The mean of specific activity due to radionuclides of 226Ra, 232Th and 40K was found to be (20±4), (11± 2),(320±18) (gypsum), (41±8), (27±5), (410±27) (clay), (58±11), (18±3), (321±20) (iron ore) and (37.6±6), (11.8±3),phate resistant cement (S.R.C.), clinker and white cement, while the mean specific activities of 226Ra and 232Th are activities (concentrations) are in the same range as the data released in other countries. The calculated radiation hazard parameters for all the samples are still lower than the acceptable values in Egypt and other countries.

  20. Wyodak-Anderson clinker in the Powder River Basin, Wyoming and Montana (prbclkg.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This ArcView shapefile contains a polygon representation of the Wyodak-Anderson clinker in the Powder River Basin, Wyoming and Montana. This theme was created...

  1. Natural Radionuclide Contents in Raw Materials and the Aggregate Finished Product from Dangote Cement Plc, Obajana, Kogi State, North Central Nigeria

    Directory of Open Access Journals (Sweden)

    J.O. Ajayi

    2012-11-01

    Full Text Available Assessment of gamma ray activity in raw materials and the end product in Dangote Cement from Dangote Cement Plc, Obajana and Kogi State has been investigated in this study. Gamma ray spectrometry that possesses scintillation detector was used to analyze the samples collected from the company. Samples collected as raw materials are limestone, clay, gypsum and laterite and cement as finished product. The 40K, 238U, 232Th activity concentration were detected. The concentration of 40K range from 4649±366 to 0±65 Bq/Kg with highest value in limestone and lowest in laterite. The 238U concentration is highest in gypsum range from 696±233 to 41±27 Bq/Kg in laterite. 232Th activity is below detectable limit in all the raw materials but it has activity concentration of 40±26 Bq/Kg in the finished product which may be traceable to the fact that some finished additives are present which are not in the basic raw materials of this cement under investigation. It is concluded that the natural radionuclide measured for 40K, 238U and 232Th has mean activities of 2189.75±219.5, 331.25±132.25 and 0±31 Bq/Kg respectively, while its corresponding mean absorbed dose rate in air at 1 m above the ground was calculated to be 235.61 nGy/h or 2.064 mSv/y and the aggregate finished product (cement has absorbed dose rate of 342.22 nGy/h and an effective dose equivalent of 2.998 mSv/y. The calculated absorbed doses in nGy/h and mSv/y shows that Dangote cement under consideration has higher activities of the isotopes than the permissible level suggested by ICRP (80 nGy/h or 0.7 mSv/y

  2. Utilization of CO2 in High Performance Building and Infrastructure Products

    Energy Technology Data Exchange (ETDEWEB)

    DeCristofaro, Nicholas [Solidia Technologies Inc., Piscataway, NJ (United States)

    2015-11-01

    -core slabs, and aerated concrete were produced to verify the utility of the CO2-curing process. These products exhibited a range of part dimensions and densities that were representative of the precast concrete industry. In the subsequent Demonstration of Commercial Development phase, the characteristics and performance of Solidia Cement made at a LafargeHolcim cement plant were established. This Solidia Cement was then used to demonstrate the CO2-curing process within operating concrete plants. Pavers, concrete masonry units and roofing tiles were produced according to ASTM and manufacturer specifications. A number of attractive manufacturing economies were recognized when Solidia Cement-based concrete parts were compared to their Portland cement based counterparts. These include reduced raw materials waste, reduced dependence on admixtures to control efflorescence, shorter curing time to full concrete strength, faster equipment clean-up, reduced equipment maintenance, and improved inventory management. These economies make the adoption of the Solidia Cement / CO2-curing process attractive even in the absence of environmental incentives. The culminating activity of the Demonstration of Commercial Development phase was the conversion of 10% of the manufacturing capacity at a concrete paver and block company from Portland cement-based products to Solidia Cement-based products. The successful completion of the Demonstration of Commercial Development phase clearly illustrated the environmental benefits associated with Solidia Cement and Solidia Concrete technologies. The industrial production of Solidia Cement, as a low-lime alternative to traditional Portland cement, reduces CO2 emissions at the cement kiln from 816 kg of CO2 per tonne of Portland cement clinker to 570 kg per tonne of Solidia Cement clinker. Industrial scale CO2-curing of Solidia Concrete sequestered a net of 183 kg of CO2 per tonne of Solidia Cement used in concrete pavers. Taken together, these two effects

  3. Production of lightweight aggregates from coal fly ash and municipal wastewater sludge; Produktion af letvaegtsklinker paa baggrund af aske med et hoejt restkulindhold og spildevandsslam fra kommunale rensningsanlaeg

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-12-01

    The municipalities have difficulties in disposing the wastewater sludge. To use wastewater sludge in agriculture limit values for the content of hazardous substanceshave have been established. These limit values have been tightened in 2000, and the municipalities therefore need alternative ways of disposal. Wastewater sludge combusted in solid waste incineration plants will result in slag corresponding to 40-45% solid matter, mainly sand. Wastewater sludge used as additive in production of light clinkers, gives 100% utilization of the sludge. This project uses wet wastewater sludge, which means that the municipalities do not need to invest in new natural gas fired drying plants. USA has for many years had a similar production, and in Denmark Aalborg Portland Cement uses 7.500 tons of wastewater sludges (100% solid matter) annually in the cement production. Satisfactory laboratory tests and full scale tests on a Danish plant, Hingevaerket, is carried out. For the full scale tests about 40 tons of sludge and about 30 tons of coal fly ash were used. Washing out tests with the new light clinkers have been carried out, and the result was acceptable. Furthermore, the flue gas was analysed for content of mercury before and after the full scale test. Thus there are no insoluble technical problems in relation to addition of wastewater sludge and coal fly ash. (EHS)

  4. Qualitative and quantitative evaluation of chrysotile and crocidolite fibers with IR-spectroscopy: application to asbestos-cement products.

    Science.gov (United States)

    Balducci, D; Valerio, F

    1986-01-01

    Infrared (IR) spectrophotometry allows simple and quick qualitative and quantitative evaluations of different kinds of asbestos, as well as of other inorganic particles. In particular, chrysotile and crocidolite have characteristic IR spectra and optical density measures of 2,710 nm band for chrysotile, of 12,820 nm band for crocidolite permit quantitative evaluation of each fiber alone or in mixture. IR spectra also give informations about changes of fiber structure and of chemical composition due, for example, to thermal treatment or acid leaching. The analytical method we developed can detect levels as low as 0.1 mg of fiber in a 300 mg disk of KBr using a low cost IR spectrophotometer. The use of a Fourier Transform IR spectrophotometer (FTIR) improves dramatically the sensitivity and selectivity. Computer assisted analysis of spectra offers the possibility to reduce matrix interferences and to compare different spectra. Examples of IR technique applied to asbestos-cement products and insulating materials are presented.

  5. Design, Explanation, and Evaluation of Training Model Structures Based on Learning Organization--In the Cement Industry with a Nominal Production Capacity of Ten Thousand Tons

    Science.gov (United States)

    Rahimian, Hamid; Kazemi, Mojtaba; Abbspour, Abbas

    2017-01-01

    This research aims to determine the effectiveness of training based on learning organization in the staff of cement industry with production capacity over ten thousand tons. The purpose of this study is to propose a training model based on learning organization. For this purpose, the factors of organizational learning were introduced by…

  6. INFLUENCE OF BARIUM OXIDE ADDITIONS ON PORTLAND CLINKER

    OpenAIRE

    Anezka Zezulova; Theodor Stanek; Opravil Tomas

    2016-01-01

    Nowadays, nuclear power plants are widespread around the world and research is of great interest. Together with nuclear research, shielding of different types of radiation is an important current topic of research aiming at their safety. Portland cement has been an elementary building material for centuries. Since barium is very efficient in shielding different types of radiation, it can be assumed that the radiation shielding capability of cement can be improved by incorporation of barium. ...

  7. Cancer mortality in towns in the vicinity of installations for the production of cement, lime, plaster, and magnesium oxide.

    Science.gov (United States)

    García-Pérez, Javier; López-Abente, Gonzalo; Castelló, Adela; González-Sánchez, Mario; Fernández-Navarro, Pablo

    2015-06-01

    Our objective was to investigate whether there might be excess cancer mortality in the vicinity of Spanish installations for the production of cement, lime, plaster, and magnesium oxide, according to different categories of industrial activity. An ecologic study was designed to examine municipal mortality due to 33 types of cancer (period 1997-2006) in Spain. Population exposure to pollution was estimated on the basis of distance from town to industrial facility. Using spatial Besag-York-Mollié regression models with integrated nested Laplace approximations for Bayesian inference, we assessed the relative risk of dying from cancer in a 5-km zone around installations, analyzed the effect of category of industrial activity according to the manufactured product, and conducted individual analyses within a 50-km radius of each installation. Excess all cancer mortality (relative risk, 95% credible interval) was detected in the vicinity of these installations as a whole (1.04, 1.01-1.07 in men; 1.03, 1.00-1.06 in women), and, principally, in the vicinity of cement installations (1.05, 1.01-1.09 in men). Special mention should be made of the results for tumors of colon-rectum in both sexes (1.07, 1.01-1.14 in men; 1.10, 1.03-1.16 in women), and pleura (1.71, 1.24-2.28), peritoneum (1.62, 1.15-2.20), gallbladder (1.21, 1.02-1.42), bladder (1.11, 1.03-1.20) and stomach (1.09, 1.00-1.18) in men in the vicinity of all such installations. Our results suggest an excess risk of dying from cancer, especially in colon-rectum, in towns near these industries.

  8. Simultaneous sand control and liner cement system: keeping well productivity by optimizing drilling and completion operations in mature fields

    Energy Technology Data Exchange (ETDEWEB)

    Sa, Andrea Nicolino de; Silva, Dayana Nunes e; Calderon, Agostinho [Petroleo Brasileiro S.A. (PETROBRAS), Rio de janeiro, RJ (Brazil)

    2012-07-01

    The need to reduce oil extraction costs by increasing the recovery factor in mature fields unconsolidated sandstone reservoirs motivated the development of drilling and completion techniques that integrate the various interfaces of engineering the well, resulting in a final well configuration that provides maximum oil production at a lower cost. Due to the continued growth of drilling and completion of new wells or deviation of old wells in the design of mesh density field with an advanced degree of exploitation, PETROBRAS took the challenge to seek options for projects well, in order to maintain productivity and reduce their construction time, with the optimization of drilling and sand control systems. To achieve these goals, PETROBRAS developed the SCARS - Simultaneous Sand Control and Liner Cementing System, a pioneer technique in the global oil industry, which consists of a one trip sequence of operations in which sand control screens and liner are installed followed by the open hole gravel pack operation performed with the alpha and beta waves deposition technique, using a non aqueous system as a carrier fluid. The sequence is completed by liner cementing in the same trip. The great success of this project was based on the definition of a specific application scenario and demands allowing optimization of the system. This project started with the development of a non aqueous system as a gravel pack carrier fluid in order to perform an open hole gravel pack with the alpha/beta wave deposition technique along with the development and optimization of SCARS procedures. This article details the planning and execution phases of this project and also presents a broad description of the technical aspects. (author)

  9. Obtaining a sulfoaluminate belite cement by industrial waste

    Directory of Open Access Journals (Sweden)

    Elkhadiri, L.

    2003-06-01

    Full Text Available Sulfoaluminate belite clinkers by burning raw at moderate temperatures near 1250 °C were synthesized. The used mixtures were made by calcium carbonate blended to two industrial wastes: low calcium fly ash and phosphogypsum. The clinkers were characterised by X-Ray Diffraction (XRD, Infrared Spectroscopy (FTIR and free lime. The hydraulic behaviour of the obtained cements, by adequate clinkers with 7% of added gypsum, was followed by XRD, scaning electronic microscopy (SEM, FTIR and NMR.

    Los clínkeres belíticos de sulfoaluminatos se obtienen por cocción de crudos a temperaturas moderadas, hacia 1.250 ºC. Esos crudos se componen de carbonato de calcio mezclados con dos subproductos industriales: cenizas volantes pobres en óxido de calcio y fosfoyeso. Los clínkeres obtenidos se caracterizaron a través de Difracción de Rayos X (DRX, Espectroscopia Infrarroja por Transformada de Fourier (FTIR y por la determinación de CaO libre. El comportamiento hidráulico de los cementos elaborados de los clínkeres con el 7% de yeso se estudió por DRX, Microscopía Electrónica de Barrido (SEM, FTIR y Resonancia Magnética Nuclear (RMN

  10. Impact of kiln thermal energy demand and false air on cement kiln flue gas CO2 capture

    Directory of Open Access Journals (Sweden)

    Udara S. P. R. Arachchige, Dinesh Kawan, Lars-André Tokheim, Morten C. Melaaen

    2014-01-01

    Full Text Available The present study is focused on the effect of the specific thermal energy demand and the false air factor on carbon capture applied to cement kiln exhaust gases. The carbon capture process model was developed and implemented in Aspen Plus. The model was developed for flue gases from a typical cement clinker manufacturing plant. The specific thermal energy demand as well as the false air factor of the kiln system were varied in order to determine the effect on CO2 capture plant performance, such as the solvent regeneration energy demand. In general, an increase in the mentioned kiln system factors increases the regeneration energy demand. The reboiler energy demand is calculated as 3270, 3428 and 3589 kJ/kg clinker for a specific thermal energy of 3000, 3400 and 3800 kJ/kg clinker, respectively. Setting the false air factor to 25, 50 or 70% gives a reboiler energy demand of 3428, 3476, 3568 kJ/kg clinker, respectively.

  11. Combustion of large solid fuels in cement rotary kilns

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Anders Rooma

    2012-03-15

    The cement industry has a significant interest in replacing fossil fuels with alternative fuels in order to minimize production costs and reduce CO{sub 2} emissions. These new alternative fuels are in particular solid fuels such as refuse derived fuel (RDF), tire-derived fuel (TDF), meat and bone meal (MBM), waste wood, sewage sludge, paper and plastics. This thesis provides an insight into the utilization of solid alternative fuels in the material inlet end of rotary kilns. This position is interesting because it allows utilization of large fuel particles, thereby eliminating the need for an expensive shredding of the fuels. The challenge, however, is that the solid fuels will be mixed into the cement raw materials, which is likely to affect process stability and clinker quality, as described above. The mixing of fuels and raw materials was studied experimentally in a pilot-scale rotary drum and was found to be a fast process, reaching steady state within few drum revolutions. Thus, heat transfer by conduction from the cement raw materials to the fuel particles is a major heat transfer mechanism rather than convection or radiation from the freeboard gas above the material bed. Consequently, the temperature of the cement raw materials becomes a factor of great importance for heating the fuel particles. Combustion of different alternative fuels has been investigated experimentally in a pilot-scale rotary furnace under conditions similar to those in the material inlet end of cement rotary kilns. The main focus was on tire rubber and pine wood which are relevant fuels in this context. Heating, drying and devolatilization of alternative fuels are fast processes that primarily depend on heat transfer and fuel particle size. Devolatilization of a large wood or tire particle with a thickness of 20 mm at 900 deg. C is for example around 2 minutes. By contrast, char oxidation is a slow process which may greatly reduce the amounts of solid fuels to be utilized in the

  12. 中国水泥生产碳排放系数测算典型研究%Carbon Emission Factors for Cement Plants in China

    Institute of Scientific and Technical Information of China (English)

    赵建安; 魏丹青

    2013-01-01

    The carbon emission coefficient system of cement production is the most important basic parameter when calculating cement carbon emissions. This paper briefly introduces the accuracy and applicability of these methods, most of which contain four aspects: operational boundaries, raw material calcination emission, fuel combustion emissions and indirect emission. We selected two typical NSP clinker production lines form western China and found that the CO2 emissions factor can be reduced by using acetylene sludge, steel slag and pyrite cinder as alternative raw material, because these materials provide CaO, the basic ingredients necessary for production, and no CO2 emissions. As a result, the usual calculation method for raw material calcination emissions will not be applicable. The correct approach is to convert the type and weight ratio of all alternative raw material with CaO and MgO into a corrected parameter. There is a significant difference in classification standards, low calorific value and CO2 emission factors of coal between the IPCC default-value and China's actual use of coal in cement production. Almost all the China' s cement plants using bituminous coal as their production fuel, therefor the fuel combustion CO2 emission factor should be in the range of 250~350 kgCO2 per tonne clinker, which is 27% lower than IPCC default-value. The CO2 emission factor of unit cement is overvalued by 10%, because international researchers believe that the clinker/cement ratio of China' s cement manufacturing plants ranges from 80%~85%, while the practical value is approximately 65%. On this basis of the above, we hold opinion that CO2 emissions of China's cement production will be seriously overvalued using IPCC or WBCSD default calculation factors. Last, four techniques to reduce CO2 emissions from the cement manufacturing industries are reviewed: using alternative raw material, using alternative fuels instead of fossil fuels, reducing electricity consumption, and

  13. Freezing resistance of high iron phoasphoaluminate cement

    Science.gov (United States)

    Zhang, S. X.; Lu, L. C.; Wang, S. D.; Zhao, P. Q.; Gong, C. C.

    2017-03-01

    The influence of freeze-thaw cycle on the mechanical properties of high iron phoasphoaluminate cement was investigated in the present study. The visual examination was conducted to evaluate the surface damage. The deterioration considering the weight loss, modulus loss of relative dynamic elastic and strength loss of mortar were also investigated. The morphology of hydration products were analysed by SEM. Compared with ordinary Portland cement and sulphoaluminate cement, the frost resistance of high iron phosphoraluminate cement is better. Hydration products of high iron phoasphoaluminate cement contain sheet crystals, and a lot of gel form a dense three-dimensional network structure, which results in a lower porosity. Different from ordinary Portland cement, the hydration product of high iron phoasphoaluminate cement does not contain Ca(OH)2, and low alkalinity reduces its osmotic pressure. The lower porosity and osmotic pressure are the two main reasons which causes in the higher frost resistance of high iron phoasphoaluminate cement.

  14. Effect of the cement type on compatibility with carboxylate super plasticisers; Influencia de la naturaleza del cemento en la compatibilidad con aditivos superplastificantes basados en carboxilatos

    Energy Technology Data Exchange (ETDEWEB)

    Bundyra-Oracz, G.; Kurdowski, W.

    2011-07-01

    An empirical study was conducted to gain a fuller understanding of the interactions taking place in cement superplasticiser systems. To this end, two clinkers of clinkers of known chemical and phase composition were prepared in this study to gain insight into such interactions. One contained no tricalcium aluminate (C1), while the other had a 9% C{sub 3}A content (C2). These clinkers were ground to approximately 340 m{sup 2}/kg and blended with gypsum only or gypsum and Klein compound (3CaO{center_dot}3Al{sub 2}O{sub 3}{center_dot}CaSO{sub 4}) (1, 2). Sufficient compound was added to C1 to ensure the formation of about the same amount of ettringite after 0.5 and 1 h of hydration as found in cement C2 + gypsum. The admixture used was a carboxylate superplasticiser. Rheology measurements showed that while paste yield stress was correlated to ettringite formation, no such simple relationship was observed for plastic viscosity. Plastic viscosity depended on the total hydrates formed, i.e., not only as ettringite but also as C-S-H gel. The findings revealed that in clinkers with very low sulfate and potassium contents, the rheology of carboxylate-containing cement paste is primarily controlled by ettringite formation. (Author) 15 refs.

  15. A characterization of the inhomogeneous properties of substitute fuels for he process of cement production; Charakterisierung der inhomogenen Eigenschaften von Ersatzbrennstoffen fuer den Zementherstellungsprozess

    Energy Technology Data Exchange (ETDEWEB)

    Bluhm-Drenhaus, T.; Wirtz, S.; Scherer, V. [Ruhr-Universitaet Bochum (DE). Energieanlagen und Energieprozesstechnik (LEAT); Schroer, K.; Perumalsamy, S.; Goerner, K. [Duisburg-Essen Univ. (DE). Lehrstuhl fuer Umweltverfahrenstechnik und Anlagentechnik (LUAT); Aslan, Z.; Schaefer, S.; Hoenig, V. [Forschungsinstitut der Zementindustrie (FIZ), Duesseldorf (Germany)

    2009-07-01

    In the year 2007, the German cement industry used nearly 100 millions GJ of thermal energy in order to manufacture nearly 33 million tons of cement. Due to the high energy intensity, questions of the efficiency and the economical fuel supply have a high denotation for the operators of cement plants. Beyond this, increasingly stricter environmental regulations are to be kept. The use of economical substitute fuels particularly is interesting for the production of cement since organic pollutants can be degraded fast at the available high process temperatures. Additionally, solid residues of combustion are incorporated into the product and used materially. The portion of substitute fuels presently amounts 52 % of the thermal output of the furnace. In order to optimize the process technology of rotary kiln plants of the cement industry, the combustion behaviour of substitute fuels is examined in the context of a research project (AiF, number 15407 N). The emphasis is on the airworthy fractions from the prepared wastes of industry and trade since they are available as a mixture of different materials with relatively consistent calorific value and frequently are used. Among the contained materials there are plastics from packing materials, paper, mature timber and textile wastes which are prepared in particle sizes up to some centimetres. Based on a model fuel from plastic and cellulose containing materials, a methodology is achieved with which the entrained-flow transport and the combustion of rough, solid fuels generally are computed. In addition, instrumentation investigations are accomplished in laboratory scale and in a cement plant. The developed methodology is examined by comparing the results of numeric CFD simulations with the experimental data. The results show that a qualitative and quantitative forecast of the temporal combustion behaviour of substitute fuels considering the uncertainty is possible by the inhomogeneous composition.

  16. Incorporation of phosphorus guest ions in the calcium silicate phases of Portland cement from 31P MAS NMR spectroscopy.

    Science.gov (United States)

    Poulsen, Søren L; Jakobsen, Hans J; Skibsted, Jørgen

    2010-06-21

    Portland cements may contain small quantities of phosphorus (typically below 0.5 wt % P(2)O(5)), originating from either the raw materials or alternative sources of fuel used to heat the cement kilns. This work reports the first (31)P MAS NMR study of anhydrous and hydrated Portland cements that focuses on the phase and site preferences of the (PO(4))(3-) guest ions in the main clinker phases and hydration products. The observed (31)P chemical shifts (10 to -2 ppm), the (31)P chemical shift anisotropy, and the resemblance of the lineshapes in the (31)P and (29)Si MAS NMR spectra strongly suggest that (PO(4))(3-) units are incorporated in the calcium silicate phases, alite (Ca(3)SiO(5)) and belite (Ca(2)SiO(4)), by substitution for (SiO(4))(4-) tetrahedra. This assignment is further supported by a determination of the spin-lattice relaxation times for (31)P in alite and belite, which exhibit the same ratio as observed for the corresponding (29)Si relaxation times. From simulations of the intensities, observed in inversion-recovery spectra for a white Portland cement, it is deduced that 1.3% and 2.1% of the Si sites in alite and belite, respectively, are replaced by phosphorus. Charge balance may potentially be achieved to some extent by a coupled substitution mechanism where Ca(2+) is replaced by Fe(3+) ions, which may account for the interaction of the (31)P spins with paramagnetic Fe(3+) ions as observed for the ordinary Portland cements. A minor fraction of phosphorus may also be present in the separate phase Ca(3)(PO(4))(2), as indicated by the observation of a narrow resonance at delta((31)P) = 3.0 ppm for two of the studied cements. (31)P{(1)H} CP/MAS NMR spectra following the hydration of a white Portland cement show that the resonances from the hydrous phosphate species fall in the same spectral range as observed for (PO(4))(3-) incorporated in alite. This similarity and the absence of a large (31)P chemical shift ansitropy indicate that the hydrous (PO(4

  17. PEMANFAATAN FLY ASH SEBAGAI BAHAN CAMPURAN PEMBUATAN PORTLAND POSSOLAN CEMENT (PPC (Utilization of Fly Ash as A Mixing in Portland Pozzolan Cement (PPC Production

    Directory of Open Access Journals (Sweden)

    Ambo Upe

    2006-11-01

    Full Text Available ABSTRAK Fly ash atau abu terbang (Kode Limbah D 22.3 merupakan salah satu produk hasil pembakaran batubara yang dihasilkan PT. Semen Tonasa sebesar rata-rata 72.36 ton/hari. Telah dicoba memanfaatkan fly ash sebagai bahan campuran semen untuk menghasilkan Portland Pozzolan Cement (PPC. Selain itu, dilakukan uji Toxicity Characteristic Leaching Procedure (TCLP serta analisis kandungan logam berat dari fly ash dan PPC tersebut.  Hasil perocobaan menunjukkan bahwa fly ash memenuhi persaratan sebagai bahan campuran PPC dan memenuhi syarat peraturan pemerintah No.85/1999 tentang Pengelolaan Llimbah Bahan Berbahaya dan Beracun.   ABSTRACT Fly ash (Disposal code: D 223 is disposal produced in coal burning process of PT. Semen Tonasa. It is estimated that the produced fly ash are 72.36 ton/day. In this paper, the study examines the possibility of utilization the fly ash as a mixing material in fabrication of Portland Pozzoland Cement (PPC. Experimental results show that the produced PPC meets the standard quality requirement. The Toxicity Characteristic Leaching Procedure (TCLP also has been performed to analysis the heavy metal contained in the fly ash and PPC materials. This test indicates that all results for TCLP Metals property fill the Indonesian Government Regulation for Hazardous Waste as described in PP No. 85/1999

  18. Performance of Cement Containing Laterite as Supplementary Cementing Material

    Directory of Open Access Journals (Sweden)

    Abbas Bukhari, Z. S.

    2013-03-01

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

  19. Influence of CG With High Content of Metallic Particles as a Cement Admixture on Cement Strength

    Institute of Scientific and Technical Information of China (English)

    WAN Hui-wen; LIN Zong-shou; ZHAO Qian; HUANG Yun

    2003-01-01

    Copper gangue (CG), containing a large amount of water with grain sizes of 0.037 to 0.10mm,is an inactive industrial waste generated from copper refineries. When it is dried and used as a cement admixture, the influence of the presence of finely dispersed metallic particles in CG on the microstructure and compressive strength of cement paste has been studied.The results show that the higher the replacement of CG is,the lower the compressive strength of cement mortar is.However,the long-term strength of the specimens with 10% CG,especially after being cured for 3 months,approached to that of the plain mortar.Its mechanism was studied by an electron probe X-ray microanalyzer (EPXMA).The results indicate that a small quantity of Fe(OH)3·nH2O slowly formed from Fe2O3 in the presence of Ca(OH)2, free CaO and MgO of the clinker also slowly hydrated and formed Ca(OH)2 and Mg(OH)2 respectively,so the hardened cement paste became more compact.

  20. Plastics wastes as secondary fuel in a cement plant; Residuos plasticos como combustible secundario en una cementera

    Energy Technology Data Exchange (ETDEWEB)

    Miguel, R.; Irasarri, L.; Arnaiz, S.; Cacho, I.

    2000-07-01

    The use of secondary fuel derived from plastics wastes from municipal source has been tested in an industrial cement plant. The recovered materials have been conditioned in order to fulfill the texture, composition and energetic requirements of the cement kiln. The performed long-term trials have shown the stability of the industrial facility during the operation with this alternative fuels. Several controls carried out over gaseous emissions confirmed the absence of differences in the emitted pollutant levels when compared with normal operation. The quality of the obtained clinker, checked using the established standard measurements, was found identical to the one in a clinker prepared using conventional fuels. The LCA (Life Cycle Analysis) tool was applied to evaluate a series of environmental impacts and proved that the energetic valorization alternative is more favourable then the disposal practice. Finally, a positive economical balance reinforced the option of energy recovery previously supported by favourable technical and environmental considerations. (Author) 16 refs.

  1. Elaboration of α’L-C2S form of belite in phosphatic clinker

    Directory of Open Access Journals (Sweden)

    Puertas, F.

    1998-03-01

    Full Text Available Solid state synthesis associated to X-ray diffraction and free lime analysis have been carried out to determine proper conditions (chemical compositions, optimum time and temperature of burning under which phosphatic belitic clinker is elaborated. Raw meals, at low lime saturation factor and added phosphate, can form a clinker with high contents of α’L-C2S modification. Microcalorimetric measurements show a relative high hydraulic activity of this belite form. The phosphatic clinker exhibits a closeness hydration behaviour to the ordinary portland clinker.Se han determinado las condiciones adecuadas (composiciones químicas, tiempo y temperaturas óptimas de tratamiento para sintetizar un clínker fosfático belítico. Esas síntesis se realizaron en estado sólido; el seguimiento de los procesos se hizo a través de difracción de rayos X y por análisis de cal libre. Es posible formar un clínker con alto contenido de α’L-C2S a partir de crudos con un bajo grado de saturación de cal y con adición de fosfato. Las medidas microcalorimétricas demuestran que esa forma de belita desarrolla una actividad hidráulica relativamente elevada. El clinker fosfático presenta un comportamiento hidráulico muy parecido al del clínker portland común.

  2. Use of copper slag in the manufacture of Portland cement

    Directory of Open Access Journals (Sweden)

    Aquilar Elguézabal, A.

    2006-03-01

    Full Text Available Given its chemical and mineralogical characteristics, copper slag, a solid industrial by-product, may serve as a partial substitute for silica and hematite in raw mixes used to manufacture Portland cement clinker. The benefits of such substitution include lower production costs and energy savings. The effect of slag-containing raw mixes on the reactivity of the CaO-Si02-Al203-Fe203 system was studied at three temperatures (1,350, 1,400 and 1,450ºC. Four mixes were used: M-1 and M-2 prepared with conventional prime materials and M-3 and M-4, in which ignimbrite and hematite were substituted for slag. In M-3 the slag replaced 45.54% of the ignimbrite and 100% of the hematite, and in M-4 100% of the mineral iron. The samples were clinkerized at 1,350, 1,400 and 1,450ºC. At 1,400ºC, clinker M-3 was found to have 10.7% less free lime than M-1, while the level in M-4 it was 15.93% lower than in M-2. The presence of the main clinker phases was confirmed by X-ray diffraction, which also showed that adding slag during c/inker manufacture slightly improves raw mix burnability without generating new unwanted phases. Consequently, recovery in cement kilns would appear to be an economically and environmentally feasible alternative to coprocessing such waste, although the industrial use of slag depends on its heavy metal content.En acuerdo con las características químicas y mineralógicas de la escoria de cobre, este residuo sólido industrial puede ser utilizado en el proceso de fabricación de clínker Portland como sustituto parcial de los minerales de sílice y hematita en la formación de mezclas crudas cuyos beneficios serían: disminución de los costos de producción de mezclas crudas y del consumo calorífico. El efecto de la adición de la escoria en las mezclas crudas sobre la reactividad del sistema CaO-Si02-Al203-Fe20 3 se estudió en tres niveles de temperatura (1.350, 1.400 Y 1.450ºC. Se trabajó con cuatro mezclas crudas, M-1 y M

  3. Technology status of production of SA integrated with cement from phosphogypsum%磷石膏制硫酸联产水泥的技术现状

    Institute of Scientific and Technical Information of China (English)

    鲍树涛

    2011-01-01

    介绍石膏制硫酸联产水泥技术的发展背景、技术现状和鲁北磷石膏制硫酸联产水泥装置的工艺流程、主要设备、原材料要求、中间产品控制、产品质量、稳定操作要点、成本及效益情况,提出推广磷石膏制硫酸联产水泥意义重大。%The development background and technology status of the production of SA integrated with cement from gypsum are introduced. The process, main equipment, demand of raw material, middling product control, product quality, stable operation points, costs and benefits situation for production of SA integrated with cement from phosphogypsum in Lubei Group are introduced, the important significance of popularizing production of SA integrated with cement from phosphogypsum is proposed.

  4. Study on the preparation of high early strength slag Portland cement with high dosage of finely ground slag%用矿渣微粉配制高掺量早强矿渣水泥的研究

    Institute of Scientific and Technical Information of China (English)

    蒋永惠; 汪小东; 陈伟; 孙谋远; 王家军

    2001-01-01

    通过正交试验研究了不同细度、掺量的矿渣微粉和熟料对矿渣水泥性能的影响。试验发现,影响矿渣水泥 3d、 28d强度的主次因素不同, 3d强度主要受矿渣细度的影响, 28d强度则主要受矿渣掺量影响。采用分别粉磨后混合的生产工艺,用一定细度的矿渣微粉可以生产出掺量较高、早强性能好的矿渣水泥。%Effect of the fineness and dosage of finely ground slag and clinker on the performance of cement was studied through cross experiment. It was found that different factors exerted varying effect on the 3d and 28d strength of the slag cement, the 3d strength was mainly affected by the fineness of slag, while the 28d strength was dominated by the content of slag addition. The adoption of mixing after separate grinding process and the addition of finely ground slag with certain fineness can ensure the production of high early strength slag Portland cement with high dosage of finely ground slag.

  5. Mercury enrichment and its effects on atmospheric emissions in cement plants of China

    Science.gov (United States)

    Wang, Fengyang; Wang, Shuxiao; Zhang, Lei; Yang, Hai; Wu, Qingru; Hao, Jiming

    2014-08-01

    The cement industry is one of the most significant anthropogenic sources of atmospheric mercury emissions worldwide. In this study of three typical Chinese cement plants, mercury in kiln flue gas was sampled using the Ontario Hydro Method (OHM), and solid samples were analyzed. Particulate matter recycling, preheating of raw materials, and the use of coal and flue gas desulfurization derived gypsum contributed to emissions of Hg in the air and to accumulation in cement. Over 90% of the mercury input was emitted into the atmosphere. Mercury emission factors were 0.044-0.072 g/t clinker for the test plants. The major species emitted into the atmosphere from cement plants is oxidized mercury, accounting for 61%-91% of the total mercury in flue gas. The results of this study help improve the accuracy of the mercury emission inventory in China and provide useful information for developing mercury controls.

  6. Assessment of polycyclic aromatic hydrocarbons (PAHs) in soil of a Natural Reserve (Isola delle Femmine) (Italy) located in front of a plant for the production of cement.

    Science.gov (United States)

    Orecchio, Santino

    2010-01-15

    Isola delle Femmine Natural Reserve is a very little isle about 15 km from the centre of Palermo, in front of a plant for the production of cement and about 600 m from coast. In the present research, profiles soil PAHs were obtained for 16 sites within the reserve and for 8 stations on the rural soil taken as reference. summation Sigma PAHs, in the soil of investigated area, ranged from 35 to 545 microg/kg. With the aim to find the origin of PAHs in the soil of Isola delle Femmine, we compare the distribution of single analytes in the investigated area with those of the reference rural area (Monte Raffo Rosso), with those of atmospheric urban particulate collected at Palermo along with reported of emissions of some cement plants. The island's investigated area showed a high amount of 4- and 5-rings PAHs, whereas 3-ring PAHs are present mainly in the emission of cement plants (from literature). The percentage of 3-, 4-, 5- and 6-rings PAHs determined in samples of Isola delle Femmine are similar to those of the reference rural soils and to those of urban atmospheric particulate. Cement plant activity has a negligible weight on the presence of PAHs in the soil of Isola delle Femmine.

  7. Investigation on the potential of waste cooking oil as a grinding aid in Portland cement.

    Science.gov (United States)

    Li, Haoxin; Zhao, Jianfeng; Huang, Yuyan; Jiang, Zhengwu; Yang, Xiaojie; Yang, Zhenghong; Chen, Qing

    2016-12-15

    Although there are several methods for managing waste cooking oil (WCO), a significant result has not been achieved in China. A new method is required for safe WCO management that minimizes the environmental threat. In this context, this work was developed in which cement clinker and gypsum were interground with various WCOs, and their properties, such as grindability, water-cement ratio required to achieve a normal consistency, setting times, compressive strength, contents of calcium hydroxide and ettringite in the hardened paste, microstructure and economic and environmental considerations, were addressed in detail. The results show that, overall, WCO favorably improves cement grinding. WCO prolonged the cement setting times and resulted in longer setting times. Additionally, more remarkable effects were found in cements in which WCO contained more unsaturated fatty acid. WCOs increased the cement strength. However, this enhancement was rated with respect to the WCO contents and components. WCOs decreased the CH and AFt contents in the cement hardened paste. Even the AFt content at later ages was reduced when WCO was used. WCO also densify microstructure of the hardened cement paste. It is economically and environmentally feasible to use WCOs as grinding aids in the cement grinding process. These results contribute to the application of WCOs as grinding aids and to the safe management of WCO. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Technology Roadmaps: Cement

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    To support its roadmap work focusing on key technologies for emissions reductions, the International Energy Agency (IEA) also investigated one particular industry: cement. Cement production includes technologies that are both specific to this industry and those that are shared with other industries (e.g., grinding, fuel preparation, combustion, crushing, transport). An industry specific roadmap provides an effective mechanism to bring together several technology options. It outlines the potential for technological advancement for emissions reductions in one industry, as well as potential cross-industry collaboration.

  9. Recycling Jorf Lasfar fly ash as an additive to cement

    Directory of Open Access Journals (Sweden)

    Hamadi A

    2012-09-01

    Full Text Available Recycling fly ash is a good example of valorization of waste. It gives a solution the environmental problem by avoiding land filling, and reducing CO2 emission in the atmosphere. In this work we studied the physical-chemical characteristics of Jorf Lasfar fly ash. The parameters investigated were particle size, density, specific surface Blaine, chemical and mineralogical compositions. The techniques used are scanning electronic microscope (SEM, transmission electronic microscope (TEM, X-rays fluorescence (XRF, X-rays diffraction (XRD and atomic spectrometry emission coupled with inductive plasma ICP. We also conducted a study on the mechanical behavior of type CPJ45 cements produced from a combined grinding of clinker, limestone and gypsum. The substitution of a portion of the clinker by different percentages of fly ash was conducted. We noticed that the compression and bending resistances for these mixtures went through a maximum at 28 days with the addition of 7% (by mass of ash. This result showed that the mineral and chemical compositions of this ash conferred a Pozzoulanic power to the cement studied.

  10. Qualitative and quantitative evaluation of chrysotile and crocidolite fibres with infrared spectrophotometry: application to asbestos-cement products.

    Science.gov (United States)

    Valerio, F; Balducci, D

    1989-01-01

    Infrared (IR) spectrophotometry allows simple and rapid qualitative and quantitative evaluations of different types of asbestos, as well as of other inorganic particles. In particular, chrysotile and crocidolite have characteristic IR spectra, and optical density measurements in the 2710 nm band for chrysotile and the 12820 nm band for crocidolite permit the quantitative evaluation of each fibre either alone or in mixtures. IR spectra also provide information on changes in fibre structure and in chemical composition as the result, for example, of thermal treatment or acid leaching. The analytical method that we have developed can detect amounts as small as 0.1 mg of fibre in a 300-mg disk of potassium bromide using a low-cost IR spectrophotometer. The use of a Fourier transform IR spectrophotometer dramatically improves the sensitivity and selectivity. Computer-assisted analysis of spectra offers the possibility of reducing matrix interference and of comparing different spectra. The application of the IR technique to asbestos-cement products and insulating materials is described.

  11. Topological calculation of key parameters of fibre for production of foam concrete based on cement-free nanostructured binder

    Directory of Open Access Journals (Sweden)

    KHARKHARDIN Anatoly Nikolaevich

    2016-08-01

    Full Text Available Fiber reinforcement is the process of introduction of fibers of different origins into binding system to enhance strength, stress-strain behavior of products and structures. Maximal effect of reinforcing process is possible when optimal parameters (length and consumption of fibre are determined. Moreover one need to consider particle-size composition and hardening process of binding system. In this paper the critical length of natural and sinthesized fibres as well as minimally required content in cellular systems is calculated with the mathematical apparatus of structural topology. As an example the foam concrete based on cement-free nanostructured binder with basalt fibre and microreinforcing constructional polymeric fibre is studied. Fiber diameter, refined with microstructure analysis, accomplished by SEM-microscopy and experimentally determined packing density in loose and compact state are applied as input parameters. Measurement of the fibre topological characteristics with acceptable is accomplished according to material porosity and pore size. So the minimal effective fibre length taking into account homogeneous distribution in bulk of composite matrix is less of 1 mm; minimal fibre consumption is 0,2–0,5 (by wt. %. Irrational optimization leads to unreasonable cost growth of final materials as well as formation of balling inclusions that negatively affects on final performance of composite.

  12. Thermal Shock-resistant Cement

    Energy Technology Data Exchange (ETDEWEB)

    Sugama T.; Pyatina, T.; Gill, S.

    2012-02-01

    We studied the effectiveness of sodium silicate-activated Class F fly ash in improving the thermal shock resistance and in extending the onset of hydration of Secar #80 refractory cement. When the dry mix cement, consisting of Secar #80, Class F fly ash, and sodium silicate, came in contact with water, NaOH derived from the dissolution of sodium silicate preferentially reacted with Class F fly ash, rather than the #80, to dissociate silicate anions from Class F fly ash. Then, these dissociated silicate ions delayed significantly the hydration of #80 possessing a rapid setting behavior. We undertook a multiple heating -water cooling quenching-cycle test to evaluate the cement’s resistance to thermal shock. In one cycle, we heated the 200 and #61616;C-autoclaved cement at 500 and #61616;C for 24 hours, and then the heated cement was rapidly immersed in water at 25 and #61616;C. This cycle was repeated five times. The phase composition of the autoclaved #80/Class F fly ash blend cements comprised four crystalline hydration products, boehmite, katoite, hydrogrossular, and hydroxysodalite, responsible for strengthening cement. After a test of 5-cycle heat-water quenching, we observed three crystalline phase-transformations in this autoclaved cement: boehmite and #61614; and #61543;-Al2O3, katoite and #61614; calcite, and hydroxysodalite and #61614; carbonated sodalite. Among those, the hydroxysodalite and #61614; carbonated sodalite transformation not only played a pivotal role in densifying the cementitious structure and in sustaining the original compressive strength developed after autoclaving, but also offered an improved resistance of the #80 cement to thermal shock. In contrast, autoclaved Class G well cement with and without Class F fly ash and quartz flour failed this cycle test, generating multiple cracks in the cement. The major reason for such impairment was the hydration of lime derived from the dehydroxylation of portlandite formed in the autoclaved

  13. High belite cement from alternative raw materials

    OpenAIRE

    Ghorab, H. Y.; Rizk, M.; Ibrahim, B.; Allam, M. M.

    2014-01-01

    Three high belite laboratory clinkers were prepared from traditional and alternative raw materials. Reference clinker was obtained from 77% limestone, 11% sandy clays, 11% fatty clays and 1% iron scales. The fatty clays were replaced by red brick powder in the raw meal of the second clinker and were lowered to 2% with the replacement of 10% of the limestone by egg shells in the third clinker. The SEM examination revealed clear presence of crossed striae and twinning in the rounded belite grai...

  14. Organic and inorganic pollutants from cement kiln stack feeding alternative fuels.

    Science.gov (United States)

    Conesa, Juan A; Gálvez, Araceli; Mateos, Fernán; Martín-Gullón, Ignacio; Font, Rafael

    2008-10-30

    In this work, an analysis of the emission of different pollutants when replacing partially the fuel type used in a cement kiln is done. The wastes used to feed the kiln were tyres and two types of sewage sludge. The increasing mass flow of sludge is between 700 kg h(-1) and 5,500 kg h(-1)1, for a total production of clinker of 150th(-1), whereas the fed tyres were in the flow range of 500-1,500 kg h(-1). Dioxins and furans, polycyclic aromatic hydrocarbons (PAHs) and other hydrocarbons, heavy metals, HCl and HF, CO, CO(2), NO(x) and other parameters of the stack were analyzed, according to the standard methods of sampling and determination, through more than 1 year in six series: one blank (no sewage sludge) and five more with increasing amount of sludge and/or tyres. The emission of PAHs and dioxins seems to increase with the amount of tyres fed to the kiln, probably due to the fed point used for this waste.

  15. CO2 Capture by Cement Raw Meal

    DEFF Research Database (Denmark)

    Pathi, Sharat Kumar; Lin, Weigang; Illerup, Jytte Boll

    2013-01-01

    The cement industry is one of the major sources of CO2 emissions and is likely to contribute to further increases in the near future. The carbonate looping process has the potential to capture CO2 emissions from the cement industry, in which raw meal for cement production could be used...... as the sorbent. Cyclic experiments were carried out in a TGA apparatus using industrial cement raw meal and synthetic raw meal as sorbents, with limestone as the reference. The results show that the CO2 capture capacities of the cement raw meal and the synthetic raw meal are comparable to those of pure limestone...... that raw meal could be used as a sorbent for the easy integration of the carbonate looping process into the cement pyro process for reducing CO2 emissions from the cement production process....

  16. Present Situation and Perspective of Chinese Cement Industry

    Institute of Scientific and Technical Information of China (English)

    Gao Changming

    2003-01-01

    @@ Totally, there are 12 types of cement kiln pro-duction lines in China and running with a quite differenttechnical- economical levels. The cement productionof different types product lines in 1997 ~ 2002 is shownin Table 1.

  17. HYDRATION CHARACTERISTICS OF PROMPT CEMENT IN THE PRESENCE CITRIC ACID AS RETARDER

    Directory of Open Access Journals (Sweden)

    Mohamed Heikal

    2015-03-01

    Full Text Available The aim of the present work is to study the influence of citric acid (CA as retarder on the properties of prompt cement pastes. The dosages of CA were 0.50, and 0.75, 1.00 and 1.25 mass % of prompt cement. The initial and final setting times, bulk density, compressive strength, total porosity, and hydration kinetics such as free lime, combined water contents and XRD for selected sample were investigated. The results obtained in this study showed that the addition of CA elongates the initial and final setting times and decreases the compressive strength and combined water contents, whereas, it increases the total porosity at all ages of hydration. CA retards the liberation of Ca(OH2 of prompt pastes. The free lime contents of prompt cement pastes are slightly increased up to 28 days then sharply increased up to 90 days. Thus, it is suggested that citrate sorbed onto the clinker surface and formed a protective layer around the clinker grains retarding their dissolution. The sharp increase of compressive strength at later ages after 28 days up to 90 days. The presence of 0.75 mass % citric acid achieves the initial and final setting time of the prompt cement according to the ASTM specification.

  18. 铁尾矿贝利特硫铝酸盐水泥的制备及性能研究%Preparation of Belite-sulphoaluminate Cement with Iron Tailings and its Properties

    Institute of Scientific and Technical Information of China (English)

    郑永超; 刘艳军; 李德忠; 李青

    2013-01-01

    以首云矿业股份有限公司铁尾矿、低品位矾土等为原料制备铁尾矿贝利特硫铝酸盐水泥,为铁尾矿的高附加值利用探索新的途径.研究结果表明:在生料中铁尾矿、矾土、煅烧石灰石、Al2 O3、CaSO4·2H2O的配比为10∶ 17∶ 48∶ 15∶10,煅烧温度为1 350℃,煅烧时间为20 min条件下,可制备出矿物成分以C4A3S、C2S、C4AF为主,f-CaO含量小于1.5%的铁尾矿贝利特硫铝酸盐水泥熟料.向该熟料中配入与其质量比均为8%的天然石膏和石灰石制成水泥,再按胶砂比为1∶3、水胶比为0.6制成水泥胶砂,胶砂的3d抗压强度达38.1 MPa、28 d抗压强度达52.5 MPa.%With iron tailings and low grade bauxite from Shouyun Mining Company as raw materials,the belite-sulphoaluminate cement clinker was prepared,which proposes a new way for exploring the high added value of iron tailings.The results showed that with the ratio of iron tailings,bauxite,calcined limestone,Al2 O3,CaSO4 · 2H2O of 10∶ 17∶ 48∶ 15∶10 in the raw meal,and at the calcination temperature of 1 350 ℃ for 20 min,belite-sulphoaluminate cement clinker with major components of C4A3S,C2S,C4AF and f-CaO content of less than 1.5% was prepared.Then,natural gypsum and limestone were added into the clinker with the quality ratio of 8% to prepare the cement raw meal.With the cement-sand ratio of 1∶3,and water-cement ratio of 0.6,the cement-mortar product reached the compressive strength of 38.1 MPa,at 3 d,and 52.5 MPa at 28 d.

  19. Assessment of the radiological impacts of utilizing coal combustion fly ash as main constituent in the production of cement.

    Science.gov (United States)

    Turhan, Seref; Arıkan, Ismail H; Köse, Abdullah; Varinlioğlu, Ahmet

    2011-06-01

    The purpose of this study is to assess potential radiological impacts of utilizing pulverized fly ash (PFA) as a constituent in ordinary Portland cement. For this purpose, the activity concentrations of (226)Ra, (232)Th, and (40)K in samples of PFA and Portland cement containing 15%, 20%, and 25% by mass PFA were measured using gamma-ray spectrometry with HPGe detector. The mean activity concentrations of (226)Ra, (232)Th, and (40)K were found as 366.6, 113.7, and 460.2 Bq kg( - 1), 94.2, 25.9, and 215.3 Bq kg( - 1), 113.7, 34.3, and 238.3 Bq kg( - 1), and 124.2, 41.8, and 279.3 Bq kg( - 1) for the examined samples of PFA, Portland cement with 15%, 20%, and 25% by mass PFA, respectively. Radiological parameters such as radium equivalent activity, external exposure index (activity concentration index), internal dose index (alpha index), indoor absorbed gamma dose rate, and the corresponding the annually effective dose were assessed for Portland cement samples containing three percentages (15%, 20%, and 25%) by mass PFA. The results of assessment show that all Portland cement samples are within the safe limits recommended for building materials for dwellings.

  20. Effect of the activation of a clay-base paper industry by-product on cement matrix behaviour

    Directory of Open Access Journals (Sweden)

    García, R.

    2008-12-01

    Full Text Available The present study addresses variations in the calcination temperature (600-750 ºC and kiln time (two to five hours applied to activate coated paper waste and their effect on the rheological, physical and mechanical behaviour of cement matrices containing these active additions.The results obtained showed that the conditions under which kaolinite was activated had a direct effect on the subsequent behaviour of the calcined products. At activating temperatures of over 700 ºC, pozzolanic activity and mechanical strength were observed to be lower, setting time shorter and the mortar less workable.El presente trabajo de investigación aborda la influencia de las condiciones de activación (600-750 ºC y 2-5 horas de permanencia en el horno de los lodos de papel procedente de la fabricación de papel estucado en el comportamiento reológico, físico y mecánico de las matrices de cementos elaboradas con este tipo de adiciones activas.Los resultados obtenidos muestran una influencia directa entre las condiciones de activación de la caolinita y el comportamiento posterior de los productos calcinados. Así, en condiciones de activación superiores a 700 ºC se observa una menor actividad puzolánica, tiempo de fraguado más corto, disminución de la trabajabilidad de los morteros mezcla y resistencia mecánica más baja.

  1. 铁相组分对硫铝酸钡钙水泥的影响%Influence of Iron Phase Composition on Barium Calcium Sulphoaluminate Cement

    Institute of Scientific and Technical Information of China (English)

    袁言臣; 叶正茂; 常钧

    2012-01-01

    The influence of iron phase composition of barium calcium sulphoaluminate cement is studied using pure chemical reagents as raw materials by XRD.SEM and strength testing methods. Results show that these raw materials have a fine mineral formation at 1 350℃. From macroscopic view of these clinker minerals, they change from pale green to dark green gradually with the ratio of Al to Fe decreasing. From the microstnicture of clinker minerals, these clinker minerals mainly generate a mass of rhombic dodecahedron of C2.75Ba1.25 A3 S and round granular of dicalcium silicate. Iron phase can promote Ba2+ to replace Ca2+.The hydration products are mainly hydrated barium calcium aluminum sulfur,BaSO4 and hydration calcium aluminates. When iron phase composition is C4AF, the strength can reach up to 73.2 MPa and 97.9 MPa at 1 d and 3 d curing ages.%以纯化学试剂配料,经X射线衍射仪(XRD)、扫描电子显微镜(SEM)和强度测试,研究铁相C6A2F、C4AF、C6AF2和C2F对硫铝酸钡钙水泥熟料的煅烧及性能的影响.结果表明:各生料配比试件在1 350℃时,熟料矿物形成较好;随铁相中Al与Fe的摩尔比的减小,熟料外观颜色呈浅绿色→深绿色→黑绿色变化;熟料矿物主要生成菱形十二面体的硫铝酸钡钙和卵粒状的硅酸二钙;铁相能够促进Ba2+取代Ca2+;主要水化产物为水化硫铝酸钡钙、BaSO4和水化铝酸钙.铁相组分为C4AF时,其1d和3d抗压强度分别为73.2 MPa和97.9 MPa.

  2. OBTENTION D’UN CLINKER PORTLAND CONSOMMANT PEU D’ENERGIE

    Directory of Open Access Journals (Sweden)

    L Kacimi

    2007-06-01

    Full Text Available L’objectif de notre travail consiste à diminuer la température de cuisson du clinker Portland par l'ajout de minéralisateurs dans le mélange des matières premières. Une série de composés chimiques purs, de matières naturelles et de déchets industriels ont été additionnés séparément aux mélanges crus de trois cimenteries algériennes (Zahana, Béni-Saf et Chlef. La plupart de ces additifs, avec un pourcentage ne dépassant pas 4% du mélange, ont pu diminuer la température de clinkerisation à 1300 °C. Leurs effets sur les propriétés hydrauliques du clinker sont cependant différents. Ceci est lié à la composition minéralogique et la structure des minéraux du clinker synthétisé. Les déchets industriels et les fluorures ont présenté une grande efficacité dans la baisse de la température de cuisson. Le phosphogypse et NaF ont amélioré la cristallisation des minéraux du clinker en formant un taux élevé d’alite. Ces caractéristiques expliquent l’amélioration des propriétés physiques et mécaniques de ce clinker.

  3. 水泥窑脱硝技术及其比对浅析%A brief analysis of denitration technology for cement production and the comparison

    Institute of Scientific and Technical Information of China (English)

    宋宏昌

    2013-01-01

      Based on 2 500 t/d cement production line, several denitration schemes——low NOx burning,selective non-catalytic reduc⁃tion(SNCR),staged combustion plus SNCR and selective catalytic reduction(SCR) popular in cement industry were introduced. The dif⁃ferent denitration technologies were compared from process flow,cost and running expense, and the results show that the scheme of staged combustion+SNCR is the best choice for cement industry.%  以205000t/d水泥窑为例,分析介绍了目前水泥行业主要的几种脱硝方案:低NOx燃烧器技术,选择性非催化还原技术(SNCR),分级燃烧+SNCR混合技术,选择性催化还原技术(SCR);并从工艺流程、投资和运行费用方面对各种脱硝技术进行了对比分析。结果表明,分级燃烧+选择性非催化还原技术是水泥行业脱硝方案的最佳选择。

  4. Process development for utilizing asbestos cement waste in rotary kilns for the cement industry. Final report; Erarbeitung eines Verfahrens zur stofflichen Verwertung von zementgebundenen Asbestprodukten in Drehrohroefen fuer die Zementindustrie. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Schlegel, R.; Kieser, J.; Kraehner, A.

    1999-11-01

    The law for recycling and waste demands the utilization also for waste of asbestos cement (ac). The procedure of thermal utilization of ac in the flame of a rotary cement kiln was developed and patented by the research institute IBU-tec Weimar, Germany. The ac-material has to be pre-pulverized and grinded to a degree of fineness of R{sub 90}<15%. Considerations of safety engineering lead to the idea of common fine grinding of old oil (oo) and ac. This new procedure was searched in FuE-project in 1998/99 (financial support by BMBF). A mash of ac and oo was generated as a utilization product ready for firing which was injected into the flame of the rotary cement kiln. This particles of ac smelt to spherical shaped particles at a temperature above 1500 C. They were utilized by clinker formation. The material and gas stream leaving the kiln does not contain fibres of asbestos. This was demonstrated in a small equipment burning test. The industrial realization concerning cement plant Ruedersdorf, near Berlin, was searched, technologically described and safety engineeringly and financially assessed by a project study. Process-technical and financial advantages were seen for the dry fine grinding. The wet fine grinding with old oil could be used in cement plants using old oil as fuel. (orig.) [German] Das Kreislaufwirtschafts- und Abfallgesetz (1994) fordert u.a. die stoffliche Verwertung auch fuer Asbestzementabfaelle (AZ). Das vom Institut fuer Baustoff- und Umweltschutz-Technologie Weimar 1995 entwickelte und patentierte Verfahren zur thermischen Verwertung von AZ in der Flamme eines Zementdrehrohrofens erfuellt diese Forderung. Das AZ-Material muss vorzerkleinert und bis zur Rohmehlfeinheit (R{sub 90}<15%) feingemahlen werden. Sicherheitstechnische Ueberlegungen fuehrten zu der Idee, die Feinmahlung zusammen mit Altoel (AOe) zu erproben. Diese Verfahrensvariante wurde im Rahmen eines FuE-Projektes 1998/99 untersucht (finanzielle Foerderung durch das BMBF). Als

  5. Osteotransductive bone cements.

    Science.gov (United States)

    Driessens, F C; Planell, J A; Boltong, M G; Khairoun, I; Ginebra, M P

    1998-01-01

    Calcium phosphate bone cements (CPBCs) are osteotransductive, i.e. after implantation in bone they are transformed into new bone tissue. Furthermore, due to the fact that they are mouldable, their osteointegration is immediate. Their chemistry has been established previously. Some CPBCs contain amorphous calcium phosphate (ACP) and set by a sol-gel transition. The others are crystalline and can give as the reaction product dicalcium phosphate dihydrate (DCPD), calcium-deficient hydroxyapatite (CDHA), carbonated apatite (CA) or hydroxyapatite (HA). Mixed-type gypsum-DCPD cements are also described. In vivo rates of osteotransduction vary as follows: gypsum-DCPD > DCPD > CDHA approximately CA > HA. The osteotransduction of CDHA-type cements may be increased by adding dicalcium phosphate anhydrous (DCP) and/or CaCO3 to the cement powder. CPBCs can be used for healing of bone defects, bone augmentation and bone reconstruction. Incorporation of drugs like antibiotics and bone morphogenetic protein is envisaged. Load-bearing applications are allowed for CHDA-type, CA-type and HA-type CPBCs as they have a higher compressive strength than human trabecular bone (10 MPa).

  6. A non-destructive test method to monitor corrosion products and corrosion-induced cracking in reinforced cement based materials

    DEFF Research Database (Denmark)

    Michel, Alexander; Pease, Bradley Justin; Peterova, Adela;

    2011-01-01

    ) was conducted to describe the impact of water-to-cement ratio and corrosion current density (i.e., corrosion rate) on the reinforcement corrosion process. Focus was placed, in particular on the determination of the corrosion accommodating region (CAR) and time to corrosion-induced cracking. Experimental results...

  7. Effect of alkali ions on the strength development of cement paste by Mössbauer spectrometry

    Science.gov (United States)

    Hassaan, M. Y.; Moutawie, M. A.; Eissa, N. A.

    1989-03-01

    Two clinker raw mixtures (83 wt% limestone +12 wt% clay +5 wt% α-Fe2O3) were fired at 1150°C for three hours in open furnace, each with 100 wt%-in addition-of an alkali carbonate (Na2CO3 and K2CO3) respectively. Each produced cliker was mixed with 5 wt% natural gypsum to produce portland cement, then with 25 wt% tap water. Compressive strength, ultrasonic pulse test, X-ray diffraction and Mossbauer effect measurements were carried out each at different times of hydration (21, 28 and 45 days). The effect of alkali ions on the strength development of cement pastes is discussed, the accuracy of Mössbauer, spectrometer in determining the cement strength is demonstrated.

  8. Valorization of electric arc furnace primary steelmaking slags for cement applications.

    Science.gov (United States)

    Kim, Hyung-Seok; Kim, Kee-Seok; Jung, Sung Suk; Hwang, Jin Ill; Choi, Jae-Seok; Sohn, Il

    2015-07-01

    To produce supplementary cementitious materials from electric arc furnace (EAF) slags, FeO was reduced using a two-stage reduction process that included an Al-dross reduction reaction followed by direct carbon reduction. A decrease in FeO was observed on tapping after the first-stage reduction, and further reduction with a stirred carbon rod in the second-stage reduction resulted in final FeO content below 5wt%, which is compatible with cement clinker applications. The reduced electric arc furnace slags (REAFS) mixed with cement at a unit ratio exhibited physical properties comparable to those of commercialized ground granulated blast furnace slags (GGBFS). Confocal laser scanning microscopy (CLSM) was used to obtain fundamental information on the cooling characteristics and conditions required to obtain amorphous REAFS. REAFS can be applied in cement mixtures to achieve the hydraulic properties needed for commercial use. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Carbonation Resistance of Sulphoaluminate Cement-based High Performance Concrete

    Institute of Scientific and Technical Information of China (English)

    ZHANG Decheng; XU Dongyu; CHENG Xin; CHEN Wen

    2009-01-01

    The influences of water/cement ratio and admixtures on carbonation resistance of sulphoaluminate cement-based high performance concrete(HPC)were investigated.The experimental results show that with the decreasing water/cement ratio,the carbonation depth of sulphoaluminate cement-based HPC is decreased remarkably,and the carbonation resistance capability is also improved with the adding admixtures.The morphologies and structure characteristics of sulphoaluminate cement hydration products before and after carbonation were analyzed using SEM and XRD.The analysis results reveal that the main hydration product of sulphoaluminate cement,that is ettringite(AFt),de-composes after carbonation.

  10. Substantial global carbon uptake by cement carbonation

    Science.gov (United States)

    Xi, Fengming; Davis, Steven J.; Ciais, Philippe; Crawford-Brown, Douglas; Guan, Dabo; Pade, Claus; Shi, Tiemao; Syddall, Mark; Lv, Jie; Ji, Lanzhu; Bing, Longfei; Wang, Jiaoyue; Wei, Wei; Yang, Keun-Hyeok; Lagerblad, Björn; Galan, Isabel; Andrade, Carmen; Zhang, Ying; Liu, Zhu

    2016-12-01

    Calcination of carbonate rocks during the manufacture of cement produced 5% of global CO2 emissions from all industrial process and fossil-fuel combustion in 2013. Considerable attention has been paid to quantifying these industrial process emissions from cement production, but the natural reversal of the process--carbonation--has received little attention in carbon cycle studies. Here, we use new and existing data on cement materials during cement service life, demolition, and secondary use of concrete waste to estimate regional and global CO2 uptake between 1930 and 2013 using an analytical model describing carbonation chemistry. We find that carbonation of cement materials over their life cycle represents a large and growing net sink of CO2, increasing from 0.10 GtC yr-1 in 1998 to 0.25 GtC yr-1 in 2013. In total, we estimate that a cumulative amount of 4.5 GtC has been sequestered in carbonating cement materials from 1930 to 2013, offsetting 43% of the CO2 emissions from production of cement over the same period, not including emissions associated with fossil use during cement production. We conclude that carbonation of cement products represents a substantial carbon sink that is not currently considered in emissions inventories.

  11. 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 ...

  12. Design, quality, and quality assurance of solid recovered fuels for the substitution of fossil feedstock in the cement industry.

    Science.gov (United States)

    Sarc, R; Lorber, K E; Pomberger, R; Rogetzer, M; Sipple, E M

    2014-07-01

    This paper describes the requirements for the production, quality, and quality assurance of solid recovered fuels (SRF) that are increasingly used in the cement industry. Different aspects have to be considered before using SRF as an alternative fuel. Here, a study on the quality of SRF used in the cement industry is presented. This overview is completed by an investigation of type and properties of input materials used at waste splitting and SRF production plants in Austria. As a simplified classification, SRF can be divided into two classes: a fine, high-calorific SRF for the main burner, or coarser SRF material with low calorific value for secondary firing systems, such as precombustion chambers or similar systems. In the present study, SRFs coming from various sources that fall under these two different waste fuel classes are discussed. Both SRFs are actually fired in the grey clinker kiln of the Holcim (Slovensko) plant in Rohožnik (Slovakia). The fine premium-quality material is used in the main burner and the coarse regular-quality material is fed to a FLS Hotdisc combustion device. In general, the alternative fuels are used instead of their substituted fossil fuels. For this, chemical compositions and other properties of SRF were compared to hard coal as one of the most common conventional fuels in Europe. This approach allows to compare the heavy metal input from traditional and alternative fuels and to comment on the legal requirements on SRF that, at the moment, are under development in Europe. © The Author(s) 2014.

  13. Emissions of PCDD/Fs, PBDD/Fs, dioxin like-PCBs and PAHs from a cement plant using a long-term monitoring system.

    Science.gov (United States)

    Conesa, Juan A; Ortuño, Nuria; Abad, Esteban; Rivera-Austrui, Joan

    2016-11-15

    The aim of the present work was to assess the emission of different persistent organic pollutants from a cement plant over a period of one year, under normal operational conditions. Thus, a long-term sampling device was installed in the clinker kiln stack of the cement plant. The factory uses petroleum coke as primary fuel, but also alternative fuels such as solid recovered fuel (SRF), automotive shredder residue (ASR), sewage sludge, waste tires, and meat and bone meal (MBM) wastes, with an energy substitution level of about 40%. Both PCDD/Fs (together with dl-PCBs) and PBDD/Fs were continuously sampled, with a total of ten samples collected in 2-4week periods. Also, PAHs were sampled during one-week periods, in order to evaluate their emissions in three different samples. The emission levels throughout the year were much lower than the set legal limits in all substances, being cement sector, which were 8.5ng I-TEQ/ton clinker for PCDD/Fs and 3.2ng WHO-TEQ/ton clinker for PCBs. With respect to the congener distribution, 2,3,7,8-TCDF accounts for 60 to 68% of the total toxicity for PCDD/Fs, and in PBDD/F emissions, a clear predominance of octa-substituted species (both dioxin and furan) was found.

  14. Influence of various acids on the physico–mechanical properties of pozzolanic cement mortars

    Indian Academy of Sciences (India)

    S Türkel; B Felekoǧlu; S Dulluç

    2007-12-01

    Acidic attack represents a topic of increasing significance, owing to the spread of damages of concrete structures in both urban and industrial areas. Cement type is an important factor affecting performance of cement based materials in an aggressive environment. The goal of this study was to compare the acid resistance of a pozzolanic cement (CEM IV-A/32·5) with Portland cement (CEM I 32·5) that was made from the same clinker. For this purpose, 50 mm mortar cubes were prepared with two different kinds of cement according to TS EN 196-1. After 28 days of hardening, the samples were immersed into four different concentrations of hydrochloric, nitric and sulfuric acid solutions for a period of 120 days. The changes in weight loss and compressive strength values for each acid solution within the test period were recorded. The acid resistance of mortars made from Portland cement was better than the pozzolanic cement incorporated samples after 120 days of acid attack.

  15. Chloride Transport of High Alumina Cement Mortar Exposed to a Saline Solution

    Directory of Open Access Journals (Sweden)

    Hee Jun Yang

    2016-01-01

    Full Text Available Chloride transport in different types of high alumina cement (HAC mortar was investigated in this study. Three HAC cement types were used, ranging from 52.0 to 81.1% of aluminum oxides in clinker. For the development of the strength, the setting time of fresh mortar was measured immediately after mixing and the mortar compressive strength was cured in a wet chamber at 25 ± 2°C and then measured at 1–91 days. Simultaneously, to assess the rate of chloride transport in terms of diffusivity, the chloride profile was performed by an exposure test in this study, which was supported by further experimentation including an examination of the pore structure, chloride binding, and chemical composition (X-ray diffraction analysis. As a result, it was found that an increase in the Al2O3 content in the HAC clinker resulted in an increase in the diffusion coefficient and concentration of surface chloride due to increased binding of chloride. However, types of HAC did not affect the pore distribution in the cement matrix, except for macro pores.

  16. 掺合料和水胶比对水泥基材料水化产物和力学性能的影响%Influence of admixture and water-cement ratio on hydration products and mechanical properties of cement-based materials

    Institute of Scientific and Technical Information of China (English)

    吴福飞; 侍克斌; 董双快; 陈亮亮; 慈军; 王欣; 张凯

    2016-01-01

    Admixture and water-cement ratio are important factors affecting the development of properties of cement mortar or concrete. In order to study the influence of admixtures and water-cement ratio on the hydration products and the mechanical properties of cement-based materials, the study combined hydration reaction mechanism of pure cement and silicate admixture, derived the formulae of hydration products, theoretical maximum mixing amount and total porosity of composite cement-based materials, and investigated the effects of mixing amount of cement mortar with fly ash, steel slag and lithium slag on total porosity, mechanical properties and hydration products. This paper designed 3 gradients of water-cement ratio (0.50, 0.42 and 0.34), 3 kinds of admixtures (lithium slag, fly ash and steel slag) and 2 contents (20% and 60%); the ratio of cementitious material to sand was 1:2.5, and then, molding specimen accorded with the mix of mortar in the triple mold and the mechanical properties of mortar were tested when specimen was cured to 1, 3, 7, 28 and 90 d. The results showed that, after the same content of fly ash, steel slag and lithium slag incorporation, the contents of hydration products of composite cementitious materials, i.e. calcium hydroxide (CH) and calcium silicate hydrate (CSH), and the total porosity were smaller than those of pure cement; when the water-cement ratio decreased from 0.50 to 0.34, the total porosity of cement mortar decreased from 16.0% to 9.3%, and the contents of CH and CSH increased for the compound cement-based materials with mixing amount of 5%, but the increments were not big; the porosity of fly ash, steel slag and lithium slag cement-based composite materials reduced from 16.6%, 17.2% and 16.0% to 9.9%, 10.9% and 9.3%, respectively. When the admixture amount increased to 10%, the variation of porosity and hydration products of the 3 kinds of mortar was different. The content of hydration products (CH and CSH) of composite

  17. 富氧燃烧在水泥生产中的应用%The Application of Oxygen-enriched Combustion to the Cement Production

    Institute of Scientific and Technical Information of China (English)

    杨志芳; 卿山; 王华; 邓文龙; 魏可

    2013-01-01

    随着全球能源危机的加剧,燃料价格的不断上涨及环保要求的不断提高,企业的生产成本越来越高,节能降耗和保护环境是每个企业发展的重要问题.富氧燃烧作为较新的燃烧技术在节能和减排方面的优良性能,在工业炉窑方面的应用得到了大力的推广.本试验在国内某4000 t/d水泥回转窑线上进行,根据富氧助燃试验所测定的数据,确定水泥回转窑在富氧生产工况下主要参数的运行变化规律,为水泥建材行业的节能减排工作提供重要理论和实践依据.%With the global energy crisis intensifies,rising prices for the fuel and environmental protection requirements continue to increase,causing the production cost of enterprises is more and more high,save energy and protect environment are the most important problems in the development of each enterprise.Oxygen-enriched combustion as a new combustion technology in saving energy and emission as the excellent performance,application in industrial furnaces has been strong promotion.This experiment in a domestic 4000 t/d cement rotary kiln line,according to the oxygen-rich combustion test measured data,determining the cement rotary kiln in oxygen-rich production conditions of main parameters of running changes,as the cement building materials industry energy-saving emission reduction work to provide an important basis for theory and practice.

  18. Features of the influence of carbonaceous nanoparticles on the rheological properties of cement paste and technological properties of the fine-grained concrete

    Directory of Open Access Journals (Sweden)

    TOLMACHEV Sergei Nikolaevich

    2014-10-01

    Full Text Available The article describes the technological features of the manufacture of cement concrete road with carbonaceous nanoparticles. The research was carried out to determine the influence of the carbonaceous nanoparticles (CNP on the properties of cement paste and monominerals cement clinker. The method of determination of mobility and the viscosity of the cement paste due to vibration has been developed. It is shown that the optimal content of the CNP in the cement paste leads to increase of its mobility and reduced viscosity. Introduction of CNP into the cement paste helps to prolong the life setting. The investigations of zeta potential of the suspensions of the cement and cement clinker monominerals with CNP have been done. They showed that the introduction of the CNP into suspension monominerals cement clinker tricalcium aluminate (S3A and tetracalcium alyumoferrita (S4AF leads to dramatic increase of electronegativity and the change of the sign of the potential of these monominerals to the opposite. The effect of carbonaceous nanoparticles on the mechanical and structural characteristics of the cement stone and concrete with CNP was determined. It is shown that the effectiveness of the impact of the CNP on the processes of structure decreases when shifting from submikrostructure to micro-structure and further to meso- and macrostructure. Efficacy of CNP depends on the concrete mixtures compaction method: hard mixture compression or vibropressing leads to two times larger increase in strength when introducing CNP than vibration compaction of moving mixtures. The electron-microscopic studies of the structure of vibrocompacted and pressed cement stone and concrete have been done. One can observe that in the structure of concrete with CNP there are spatial frames inside and around which tumor crystallization takes place. That intensifies the processes of structure formation. Concrete with CNP can be characterized by prevailing dense structure, the

  19. On the Measurement of Cement Clinker‘s Adherence on Basic Refractories

    Institute of Scientific and Technical Information of China (English)

    GUOZongqi; MichelRigaud

    2001-01-01

    A new sandwich test has been developed to measure the adherence of cement clinker on basic refractories to test their coatability,Statistical desings of experiment method-ology were employed for evaluations of the sandwich test.Three fractional factorial tests and one full factorial test were executed to efficiently generate data that reveal the significance of the major factors and the ruggedness to the minor factors .Its repeatability and reproducibility have been statistically confirmed to be acceptable,Evaluations on various basic bricks by the sandwich test reflect their coating performance in rotary kiln.

  20. Research Progress in Applications of Calcium Sulphoaluminate Modified Portland Cement%硫铝酸钙改性硅酸盐水泥应用研究进展∗

    Institute of Scientific and Technical Information of China (English)

    葛大顺; 马素花; 李伟峰; 于锦; 沈晓冬; 汤国芳; 蔡建; 管娟

    2015-01-01

    Calcium sulphoaluminate modified Portland cement clinker has excellent characteristics of ordinary Portland cement clinker and sulphoaluminate cement clinker.Meanwhile this cement clinker has superior stimulating effect for fly-ash.These advantages confer SMP broad application prospects.Herein,the properties and hydration characteristics of SMP are summarized,and the composite properties of SMP with different mineral admixtures and the adaptability of this cement with chemical admixtures are also discussed.In addittion,the existing problems of SMP and improvement measures are proposed.%硫铝酸钙改性硅酸盐水泥熟料兼具硅酸盐水泥熟料和硫铝酸盐水泥熟料的优良性能,同时该种水泥熟料对粉煤灰等火山灰类材料具有超强的活性激发效果,这使得硫铝酸钙改性硅酸盐水泥具有广阔的应用前景。主要概括了硫铝酸盐改性硅酸盐水泥的性能及水化特性,综述了该种水泥与不同矿物掺合料的复合性能以及与化学外加剂的适应性,提出了硫铝酸钙改性硅酸盐水泥存在的问题及改善措施。

  1. US cement industry

    Energy Technology Data Exchange (ETDEWEB)

    Nisbet, M.A.

    1997-12-31

    This paper describes the cement and concrete industry, and provides data on energy use and carbon dioxide emissions. The potential impact of an energy tax on the industry is briefly assessed. Opportunities identified for reducing carbon dioxide emissions include improved energy efficiency, alternative fuels, and alternative materials. The key factor in determining CO{sub 2} emissions is the level of domestic production. The projected improvement in energy efficiency and the relatively slow growth in domestic shipments indicate that CO{sub 2} emissions in 2000 should be about 5% above the 1990 target. However, due to the cyclical nature of cement demand, emissions will probably be above target levels during peak demand and below target levels during demand troughs. 7 figs., 2 tabs.

  2. 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.

  3. Hidration kinetics study of tlie mixed cements

    OpenAIRE

    Duque Fernández, Gabriel . L; Díaz Quintanilla, David; Zapata Sierra, Manuel; Rubio Frías, Ester

    1993-01-01

    A study of the hydration process of cements with 10% and 20% addition of a tuff from "Las Carolinas" quarry (Cienfuegos, Cuba) by different methods was done. The results obtained by different methods showed a good agreement. It was proved an increment of the hydration products, an acceleration of alite hydration and a swelling of the fixed water in mixed cements. The resistance of the cement with 10% addition is similar to that of the pure cement for ages of 28 days, whereas with 20% addition...

  4. The effectivity of bentonites in cesium retention of cemented waste products; Efetividade das bentonitas na retencao de cesio em produtos de rejeitos cimentados

    Energy Technology Data Exchange (ETDEWEB)

    Tello, Cledola Cassia Oliveira de

    2001-01-15

    The nuclear energy has been used for the human development in different areas, as in the medicine, in the agriculture, in the industry and in the environmental protection, besides the electricity generation. As in other activities, in the use of nuclear energy, residues are also generated. They are considered radioactive wastes when the contaminant content can bring a potential negative impact in the human health and in the environment. In this case they should be properly managed and should not be released without treatment. In general the waste processing consists in a volume reduction followed by solidification and/or conditioning. A number of materials can be considered as immobilisation matrices for the wastes, with the objective of maintain the radioactive material physical and chemically stable. The cement is extensively used because it is easy to obtain, there is large. experience in its use and the processing is done at room temperature. Many materials have been studied to improve the fixation characteristics of the radionuclides in the cemented product. The aim of this study was to search, among Brazilian natural materials, those that could be effective in the contaminant retention without jeopardising the process and other characteristics of the waste product. Four types of bentonite were selected to the process and product evaluation tests. Many mixtures were prepared with simulated waste, cement and bentonite in different proportions. The viscosity, set time, compressive strength and leaching were evaluated. In addition it was verified if the products were monolithic and without free water. Inactive caesium was used as tracer. The leaching resistance is the most important parameter in the product evaluation, because it indicates the retention capacity of the matrix for radionuclides when the product is in contact with the water. In 1985 leaching tests were begun and they have been continued till now and from their results it was proved that the

  5. Quantitative determination of tricalcicum aluminate in portland cement by X-ray diffraction

    Directory of Open Access Journals (Sweden)

    Sagrera Moreno, José Luis

    1989-06-01

    Full Text Available Tricalcium aluminate (C3A is one of the constitutive phase of the cement-clinker. Its concentration influences the cement behaviour in sulphate aggressive soils. Therefore its quantification is very convenient and International standards fix its content when the concrete is used in contact with soils or liquids containing sulphate compounds. There are two possibilities in order to calculate the amount of C3A in clinker phases: one consist in a mathematical calculation from the results of the chemical analysis (Bogue formulae and the order is based in X-ray diffraction, using the height of the representative peak of the C3A phase. In the present note, the experimental procedure in order to determine the C3A content from X-ray test is presented.

    El aluminato tricáicico es una de las fases constitutivas del clinker de cemento portland. Su concentración en el cemento influye en el comportamiento de éste, en las obras sometidas a la posible agresividad de diferentes sulfatos cuando entran en contacto con las estructuras que se fabrican con él. Por ello la determinación de su concentración es un dato que puede invalidar su uso en una obra. De ahí que las normas internacionales fijen la cantidad de aluminato tricáicico según se clasifique la agresividad del entorno en el que una estructura será colocada. Existen fórmulas matemáticas para calcular la concentración de cada una de las fases del clinker a partir de las concentraciones de los elementos químicos de clinker expresados en forma de óxidos. Los posibles errores en los análisis químicos producen errores en los cálculos de las concentraciones de cada fase. Para determinar la concentración de dichas fases se puede emplear también la técnica de difracción de rayos X, basándose en la medida de la altura del pico representativo de la fase que se quiere determinar.

  6. Effects of blended-cement paste chemical composition changes on some strength gains of blended-mortars.

    Science.gov (United States)

    Kirgiz, Mehmet Serkan

    2014-01-01

    Effects of chemical compositions changes of blended-cement pastes (BCPCCC) on some strength gains of blended cement mortars (BCMSG) were monitored in order to gain a better understanding for developments of hydration and strength of blended cements. Blended cements (BC) were prepared by blending of 5% gypsum and 6%, 20%, 21%, and 35% marble powder (MP) or 6%, 20%, 21%, and 35% brick powder (BP) for CEMI42.5N cement clinker and grinding these portions in ball mill at 30 (min). Pastes and mortars, containing the MP-BC and the BP-BC and the reference cement (RC) and tap water and standard mortar sand, were also mixed and they were cured within water until testing. Experiments included chemical compositions of pastes and compressive strengths (CS) and flexural strengths (FS) of mortars were determined at 7th-day, 28th-day, and 90th-day according to TS EN 196-2 and TS EN 196-1 present standards. Experimental results indicated that ups and downs of silica oxide (SiO2), sodium oxide (Na2O), and alkali at MP-BCPCC and continuously rising movement of silica oxide (SiO2) at BP-BCPCC positively influenced CS and FS of blended cement mortars (BCM) in comparison with reference mortars (RM) at whole cure days as MP up to 6% or BP up to 35% was blended for cement.

  7. Effects of Blended-Cement Paste Chemical Composition Changes on Some Strength Gains of Blended-Mortars

    Directory of Open Access Journals (Sweden)

    Mehmet Serkan Kirgiz

    2014-01-01

    Full Text Available Effects of chemical compositions changes of blended-cement pastes (BCPCCC on some strength gains of blended cement mortars (BCMSG were monitored in order to gain a better understanding for developments of hydration and strength of blended cements. Blended cements (BC were prepared by blending of 5% gypsum and 6%, 20%, 21%, and 35% marble powder (MP or 6%, 20%, 21%, and 35% brick powder (BP for CEMI42.5N cement clinker and grinding these portions in ball mill at 30 (min. Pastes and mortars, containing the MP-BC and the BP-BC and the reference cement (RC and tap water and standard mortar sand, were also mixed and they were cured within water until testing. Experiments included chemical compositions of pastes and compressive strengths (CS and flexural strengths (FS of mortars were determined at 7th-day, 28th-day, and 90th-day according to TS EN 196-2 and TS EN 196-1 present standards. Experimental results indicated that ups and downs of silica oxide (SiO2, sodium oxide (Na2O, and alkali at MP-BCPCC and continuously rising movement of silica oxide (SiO2 at BP-BCPCC positively influenced CS and FS of blended cement mortars (BCM in comparison with reference mortars (RM at whole cure days as MP up to 6% or BP up to 35% was blended for cement.

  8. Effects of Blended-Cement Paste Chemical Composition Changes on Some Strength Gains of Blended-Mortars

    Science.gov (United States)

    Kirgiz, Mehmet Serkan

    2014-01-01

    Effects of chemical compositions changes of blended-cement pastes (BCPCCC) on some strength gains of blended cement mortars (BCMSG) were monitored in order to gain a better understanding for developments of hydration and strength of blended cements. Blended cements (BC) were prepared by blending of 5% gypsum and 6%, 20%, 21%, and 35% marble powder (MP) or 6%, 20%, 21%, and 35% brick powder (BP) for CEMI42.5N cement clinker and grinding these portions in ball mill at 30 (min). Pastes and mortars, containing the MP-BC and the BP-BC and the reference cement (RC) and tap water and standard mortar sand, were also mixed and they were cured within water until testing. Experiments included chemical compositions of pastes and compressive strengths (CS) and flexural strengths (FS) of mortars were determined at 7th-day, 28th-day, and 90th-day according to TS EN 196-2 and TS EN 196-1 present standards. Experimental results indicated that ups and downs of silica oxide (SiO2), sodium oxide (Na2O), and alkali at MP-BCPCC and continuously rising movement of silica oxide (SiO2) at BP-BCPCC positively influenced CS and FS of blended cement mortars (BCM) in comparison with reference mortars (RM) at whole cure days as MP up to 6% or BP up to 35% was blended for cement. PMID:24587737

  9. Hydration and microstructure of Portland cement partially substituted with ultrafine silica

    Directory of Open Access Journals (Sweden)

    Escalante, J. I.

    2009-12-01

    Full Text Available Geothermal waste, a by-product of steam power plants that use geothermal underground resources, was studied as a possible replacement for Portland cement. This waste consists primarily in amorphous nanometric silica with traces of sodium and potassium chlorides. The replacement ratios studied were 0, 10 and 20% in cements cured at 20 and 60 ºC. X-ray diffraction analysis showed that clinker phase hydration took place earlier in the presence of the geothermal waste. Scanning electron microscopy, in turn, revealed a reduction in porosity and intense calcium hydroxide consumption as a result of the pozzolanic reaction. The pastes containing 20% waste, however, an intense cracking was observed due to the formation of alkali silica reaction gel and ettringite. Cracking was more prominent at 60 ºC but was not observed in either the neat cement or the blend with 10 % waste. The presence of these detrimental phases was attributed to the formation of Friedel’s salt in the initial hydration stages, induced by the chlorides in the geothermal material.Se investigaron pastas de cemento Portland sustituido con un desecho geotérmico, subproducto de la generación de electricidad en plantas que emplean recursos geotérmicos. El desecho está compuesto principalmente de sílice amorfa de tamaño nanométrico, con cloruros de sodio y potasio. Se investigaron cementos con niveles de substitución de 0, 10 y 20%, curados a 20 y 60 °C. En presencia del desecho geotérmico, se observó por Difracción de rayos X cuantitativa que la hidratación de las fases del clínker se aceleró; además mediante microscopía electrónica de barrido se encontró una disminución en la porosidad y un intenso consumo de hidróxido de calcio por la reacción puzolánica. Sin embargo, para pastas con 20% de desecho geotérmico, se observó agrietamiento con la presencia de gel de reacción álcali sílice y ettringita; fue más acentuado a 60 °C y no se observó para pastas de

  10. ULTRA-LIGHTWEIGHT CEMENT

    Energy Technology Data Exchange (ETDEWEB)

    Fred Sabins

    2002-07-30

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report includes results from laboratory testing of ULHS systems along with other lightweight cement systems, including foamed and sodium silicate slurries. During this project quarter, a comparison study of the three cement systems examined the effect that cement drillout has on the three cement systems. Testing to determine the effect of pressure cycling on the shear bond properties of the cement systems was also conducted. This report discusses testing that was performed to analyze the alkali-silica reactivity of ULHS in cement slurries.

  11. A Pause for China's Cement Industry

    Institute of Scientific and Technical Information of China (English)

    Li Zhen

    2009-01-01

    @@ Cement industry suffers excess productionWith the advent of global financial crisis,the Chinese government has laid out a stimulus package on infrastructure construction.Driven by the investment spree,China's cement makers are flocking to expand output capacity,which is now leading the industry into a much-higher-thanneeded state.

  12. Mechanical Properties of High Strength Concrete Containing Coal Bottom Ash and Oil-Palm Boiler Clinker as Fine Aggregates

    Directory of Open Access Journals (Sweden)

    Soofinajafi Mahmood

    2016-01-01

    Full Text Available This research aims to utilize Coal Furnace Bottom ash (CBA and Oil-Palm Boiler Clinker (OPBC as fine aggregate in concrete mix proportions. They are solid wastes from power plant and Oil Palm industry, respectively. Since these by-products do not have any primary use and are pure waste, an opportunity to use them as aggregate in concrete industry not only is economical but also will be an environmental friendly opportunity leading towards a more sustainable production chain. CBA and OPBC sands had similar grading to normal sand but have lower density and higher water absorption. In a high strength concrete, normal sand was replaced up to 25% with either CBA or OPBC. Test results showed that although water absorption of these wastes was more than normal sand but the slump value of concrete containing each of these wastes showed that these concretes had good workability. All mixes containing these wastes had slightly lower compressive strength at early ages and equivalent or higher compressive strength at later ages compared to control mix. The 28-day compressive strength of these concretes was in the range of 69–76 MPa which can be categorized as high strength concrete. In general, the performance of OPBC was better than CBA at 25% replacement level. However, it is recommended that at least 12.5% of total volume of fine aggregate in a high strength concrete is used of CBA or OPBC.

  13. The partitioning behavior of trace element and its distribution in the surrounding soil of a cement plant integrated utilization of hazardous wastes.

    Science.gov (United States)

    Yang, Zhenzhou; Chen, Yan; Sun, Yongqi; Liu, Lili; Zhang, Zuotai; Ge, Xinlei

    2016-07-01

    In the present study, the trace elements partitioning behavior during cement manufacture process were systemically investigated as well as their distribution behaviors in the soil surrounding a cement plant using hazardous waste as raw materials. In addition to the experimental analysis, the thermodynamic equilibrium calculations were simultaneously conducted. The results demonstrate that in the industrial-scale cement manufacture process, the trace elements can be classified into three groups according to their releasing behaviors. Hg is recognized as a highly volatile element, which almost totally partitions into the vapor phase. Co, Cu, Mn, V, and Cr are considered to be non-volatile elements, which are largely incorporated into the clinker. Meanwhile, Cd, Ba, As, Ni, Pb, and Zn can be classified into semi-volatile elements, as they are trapped into clinker to various degrees. Furthermore, the trace elements emitted into the flue gas can be adsorbed onto the fine particles, transport and deposit in the soil, and it is clarified here that the soil around the cement plant is moderately polluted by Cd, slightly polluted by As, Cr, Ba, Zn, yet rarely influenced by Co, Mn, Ni, Cu, Hg, and V elements. It was also estimated that the addition of wastes can efficiently reduce the consumption of raw materials and energy. The deciphered results can thus provide important insights for estimating the environmental impacts of the cement plant on its surroundings by utilizing wastes as raw materials.

  14. Effect of Ions Doping on Calcining and Hydration Properties of High-strength Low-calcium Portland Clinker%离子掺杂对高强低钙硅酸盐水泥熟料煅烧性能的影响

    Institute of Scientific and Technical Information of China (English)

    周双喜; 陈鹏飞; 喻乐华; 邓文武

    2015-01-01

    With view to the new requirements of energy-saving emission reduction and low-carbon economy, the research and development ( R&D ) of low calcium cement has great significance . This paper probes into firing different content belite cement clinkers and proportioning different raw materials, which finds out that the burnability of clinkers can be improved remarkably by ions adopting and the crystal form can be stabilized by adopting B2O3. Using chemical reagent and industrial raw materials, by chemical analysis, XRD (X-ray diffraction), lithofacies analysis and SEM, effects of ions doping on calcining and hydration properties of high strength low calcium portland clinker are discussed in details. Results show that the most suitable temperature of clinkers sintering is 1 350℃, can be in steady existence by adding stabilizers, and fossil has its best morphology under the condition of complete mineral crystallizing cement when the calcination temperature ranges from 1 400℃ to 1 450℃ with w(C2S) being 45% and w(C3S) 30% of the content.%选择几种不同生料进行配方,烧制不同含量硅酸二钙水泥熟料,在煅烧过程中通过阴离子掺杂来研究对熟料易烧性能的影响,并添加稳定剂B2O3使贝利特保持活性较高的晶型;运用XRD、岩相分析、SEM等测试手段,初步探讨了离子掺杂对高强低钙硅酸盐水泥熟料煅烧和水化性能的影响. 主要结论是,最佳的煅烧温度为1 350℃,稳定剂的加入可以促进熟料中的稳定存在;其次,当煅烧温度在1 400~1 450℃,w(C2S)含量在45%、w(C3S)含量30%时,熟料矿物结晶完整,矿物形貌最好,其早龄期的水化产物量也最多.

  15. 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.

    In 2009, ASTM and AASHTO permitted the use of up to 5% interground limestone in ordinary portland cement (OPC) as a part of a change to ASTM C150/AASHTO M85. When this work was initiated a new proposal was being discussed that would enable up to 15% interground limestone cement to be considered in ASTM C595/AASHTO M234. This work served to provide rapid feedback to the state department of transportation and concrete industry for use in discussions regarding these specifications. Since the time this work was initiated, ASTM C595/AASHTO M234 was passed (2012c) and PLCs are now able to be specified, however they are still not widely used. The proposal for increasing the volume of limestone that would be permitted to be interground in cement is designed to enable more sustainable construction, which may significantly reduce the CO2 that is embodied in the built infrastructure while also extending the life of cement quarries. Research regarding the performance of cements with interground limestone has been conducted by the cement industry since these cements became widely used in Europe over three decades ago, however this work focuses on North American Portland Limestone Cements (PLCs) which are specifically designed to achieve similar performance as the OPCs they replace.This thesis presents a two-phase study in which the potential for application of cements containing limestone was assessed. The first phase of this study utilized a fundamental approach to determine whether cement with up to 15% of interground or blended limestone can be used as a direct substitute to ordinary portland cement. The second phase of the study assessed the concern of early age shrinkage and cracking potential when using PLCs, as these cements are typically ground finer than their OPC counterparts. For the first phase of the study, three commercially produced PLCs were obtained and compared to three commercially produced OPCs made from the same clinker. An additional cement was tested

  16. Technology Roadmap: Low-Carbon Technology for the Indian Cement Industry

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-06-01

    The Indian cement industry is one of the most efficient in the world. Its efforts to reduce its carbon footprint by adopting the best available technologies and environmental practices are reflected in the achievement of reducing total CO2 emissions to an industrial average of 0.719 tCO2/t cement in 2010 from a substantially higher level of 1.12 tCO2/t cement in 1996. However, because the manufacturing process relies on the burning of limestone, it still produced 137 MtCO2 in 2010 – approximately 7% of India’s total man-made CO2 emissions. Yet opportunity for improvement exists, particularly in relation to five key levers that can contribute to emissions reductions: alternative fuel and raw materials; energy efficiency; clinker substitution; waste heat recovery and newer technologies. This roadmap sets out one pathway by which the Indian cement industry can reach its targets to improve energy efficiency and reduce CO2 emissions by 2050, thereby laying the foundation for low-carbon growth in the years beyond. The Technology Roadmap: Low-Carbon Technology for the Indian Cement Industry builds on the global IEA technology roadmap for the cement sector developed by the IEA and the World Business Council for Sustainable Development’s Cement Sustainability Initiative. It outlines a possible transition path for the Indian cement industry to reduce its direct CO2 emissions intensity to 0.35 tCO2/t cement and support the global goal of halving CO2 emissions by 2050.

  17. Interaction of ordinary Portland cement and Opalinus Clay: Dual porosity modelling compared to experimental data

    Science.gov (United States)

    Jenni, A.; Gimmi, T.; Alt-Epping, P.; Mäder, U.; Cloet, V.

    2017-06-01

    Interactions between concrete and clays are driven by the strong chemical gradients in pore water and involve mineral reactions in both materials. In the context of a radioactive waste repository, these reactions may influence safety-relevant clay properties such as swelling pressure, permeability or radionuclide retention. Interfaces between ordinary Portland cement and Opalinus Clay show weaker, but more extensive chemical disturbance compared to a contact between low-pH cement and Opalinus Clay. As a consequence of chemical reactions porosity changes occur at cement-clay interfaces. These changes are stronger and may lead to complete pore clogging in the case of low-pH cements. The prediction of pore clogging by reactive transport simulations is very sensitive to the magnitude of diffusive solute fluxes, cement clinker chemistry, and phase reaction kinetics. For instance, the consideration of anion-depleted porosity in clays substantially influences overall diffusion and pore clogging at interfaces. A new concept of dual porosity modelling approximating Donnan equilibrium is developed and applied to an ordinary Portland cement - Opalinus Clay interface. The model predictions are compared with data from the cement-clay interaction (CI) field experiment in the Mt Terri underground rock laboratory (Switzerland), which represent 5 y of interaction. The main observations such as the decalcification of the cement at the interface, the Mg enrichment in the clay detached from the interface, and the S enrichment in the cement detached from the interface, are qualitatively predicted by the new model approach. The model results reveal multiple coupled processes that create the observed features. The quantitative agreement of modelled and measured data can be improved if uncertainties of key input parameters (tortuosities, reaction kinetics, especially of clay minerals) can be reduced.

  18. Estimates of global, regional, and national annual CO{sub 2} emissions from fossil-fuel burning, hydraulic cement production, and gas flaring: 1950--1992

    Energy Technology Data Exchange (ETDEWEB)

    Boden, T.A.; Marland, G. [Oak Ridge National Lab., TN (United States); Andres, R.J. [University of Alaska, Fairbanks, AK (United States). Inst. of Northern Engineering

    1995-12-01

    This document describes the compilation, content, and format of the most comprehensive C0{sub 2}-emissions database currently available. The database includes global, regional, and national annual estimates of C0{sub 2} emissions resulting from fossil-fuel burning, cement manufacturing, and gas flaring in oil fields for 1950--92 as well as the energy production, consumption, and trade data used for these estimates. The methods of Marland and Rotty (1983) are used to calculate these emission estimates. For the first time, the methods and data used to calculate CO, emissions from gas flaring are presented. This C0{sub 2}-emissions database is useful for carbon-cycle research, provides estimates of the rate at which fossil-fuel combustion has released C0{sub 2} to the atmosphere, and offers baseline estimates for those countries compiling 1990 C0{sub 2}-emissions inventories.

  19. Determination of the products coming from the cellulose hydrolysis by a cement water; Identification et caracterisation des produits d'hydrolyse de la cellulose par une eau cimentaire

    Energy Technology Data Exchange (ETDEWEB)

    Motelier, S.; Charles, Y.; Richet, C.; Ayache, R. [CEA Saclay, Dept. d' Entreposage et de Stockage des Dechets, 91 - Gif-sur-Yvette (France)

    2001-07-01

    Capillary electrophoresis is a useful method to separate the degradation products of cellulose in cement water medium and to quantify their acid-base and complexing properties. The perfected method can be applied to all the cations having relatively soluble hydroxides. (O.M.)

  20. From natural products to polymeric derivatives of "eugenol": a new approach for preparation of dental composites and orthopedic bone cements.

    Science.gov (United States)

    Rojo, Luis; Vazquez, Blanca; Parra, Juan; López Bravo, Antonio; Deb, Sanjukta; San Roman, Julio

    2006-10-01

    Polymers with eugenol moieties covalently bonded to the macromolecular chains were synthesized for potential application in orthopedic and dental cements. First, eugenol was functionalized with polymerizable groups. The synthetic methods employed afforded two different methacrylic derivatives, where the acrylic and eugenol moieties were either directly bonded, eugenyl methacrylate (EgMA), or separated through an oxyethylene group, ethoxyeugenyl methacrylate (EEgMA). A typical Fisher esterification reaction was used for the synthesis of EgMA and EEgMA, affording the desired monomers in 80% yields. Polymerization of each of the novel monomers, at low conversion, provided soluble polymers consisting of hydrocarbon macromolecules with pendant eugenol moieties. At high conversions only cross-linked polymers were obtained, attributed to participation of the allylic double bonds in the polymerization reaction. In addition, copolymers of each eugenol derivative with ethyl methacrylate (EMA) were prepared at low conversion, with the copolymerization reaction studied by assuming the terminal model and the reactivity ratios determined according to linear and nonlinear methods. The values obtained were r(EgMA) = 1.48, r(EMA) = 0.55 and r(EEgMA) = 1.22, r(EMA) = 0.42. High molecular weight polymers and copolymers were obtained at low conversion. Analysis of thermal properties revealed a T(g) of 95 degrees C for PEgMA and of 20 degrees C for PEEgMA and an increase in the thermal stability for the eugenol derivatives polymers and copolymers with respect to that of PEMA. Water sorption of the copolymers was found to decrease with the eugenol derivative content. Both monomers EgMA and EEgMA showed antibacterial activity against Streptococcus mutans, producing inhibition halos of 7 and 21 mm, respectively. Finally, cell culture studies revealed that the copolymers did not leach any toxic eluants and showed good cellular proliferation with respect to PEMA. This study thus indicates

  1. Biodeterioration of the Cement Composites

    Science.gov (United States)

    Luptáková, Alena; Eštoková, Adriana; Mačingová, Eva; Kovalčíková, Martina; Jenčárová, Jana

    2016-10-01

    The destruction of natural and synthetic materials is the spontaneous and irreversible process of the elements cycling in nature. It can by accelerated or decelerated by physical, chemical and biological influences. Biological influences are represented by the influence of the vegetation and microorganisms (MO). The destruction of cement composites by different MO through the diverse mechanisms is entitled as the concrete biodeterioration. Several sulphur compounds and species of MO are involved in this complex process. Heterotrophic and chemolithotrophic bacteria together with fungi have all been found in samples of corroding cement composites. The MO involved in the process metabolise the presented sulphur compounds (hydrogen sulphide, elemental sulphur etc.) to sulphuric acid reacting with concrete. When sulphuric acid reacts with a concrete matrix, the first step involves a reaction between the acid and the calcium hydroxide forming calcium sulphate. This is subsequently hydrated to form gypsum, the appearance of which on the surface of concrete pipes takes the form of a white, mushy substance which has no cohesive properties. In the continuing attack, the gypsum would react with the calcium aluminate hydrate to form ettringite, an expansive product. The use supplementary cementing composite materials have been reported to improve the resistance of concrete to biodeterioration. The aim of this work was the study of the cement composites biodeterioration by the bacteria Acidithiobacillus thiooxidans. Experimental works were focused on the comparison of special cement composites and its resistance affected by the activities of used sulphur-oxidising

  2. Characterization of Moroccan coal waste: valorization in the elaboration of the Portland clinker

    Directory of Open Access Journals (Sweden)

    Belkheiri D.

    2014-04-01

    Full Text Available Coal exploited in the mine of Jerada (northeast of Morocco was accompanied by large quantities of waste. The purpose of this work is to characterize this waste with the aim of its use as a material for civil engineering. Mineral and chemical investigations on this waste in the raw state, and at different temperature of heat treatments, were carried out by various methods: X-ray fluorescence, X-ray diffraction, infrared spectroscopy. These analyzes showed that the studied waste, contain essentially a mineral part formed by silica and various clays, as well as coal’s residues. The thermal investigation of waste, by differential scanning calorimetry (DSC, revealed an exothermic phenomenon attributed to the combustion of coal residues. Other phenomena were noted on the thermograms due to the mineral part transformations. In this analysis a comparison was also made with pure coal. These characteristics of coal waste encourage studying its development in reducing energy consumption in the Portland cement manufacture. Mixtures of waste with limestone or with raw cement materials were studied, and the resulting products were analyzed by different methods.

  3. Interaction between pollutants produced in sewage sludge combustion and cement raw material.

    Science.gov (United States)

    Gálvez, Araceli; Conesa, Juan A; Martín-Gullón, Ignacio; Font, Rafael

    2007-09-01

    Nowadays the use of waste as secondary fuel in clinker kilns is an extensive practice, but the interaction between cement raw material (CRM) and the combustion gases of the fuels has not been extensively studied. Because of that, in this work the effect of the interaction of exhaust from the combustion of sewage sludge and CRM has been studied in a laboratory furnace. The experiments were performed at 300 degrees C, close to the temperature at the cyclones in a cement industry. The behavior of volatile compounds, polycyclic aromatic compounds (PAH) and polychloro dibenzo-p-dioxin and polychloro dibenzofurans (PCCD/F) were analysed in the presence or absence of CRM. The results obtained show that the presence of CRM at the outlet of the combustion gases is beneficial for the decrease of pollutant emissions.

  4. Relation between Portland cement carbonation, range of clinker burning and some expansive phenomena in the autoclave test

    Directory of Open Access Journals (Sweden)

    Ruiz de Cauna, A.

    1975-12-01

    Full Text Available Not availableEn este trabajo se estudia el doble pico que aparece en la región de altas temperaturas de las curvas derivatométricas, realizadas en atmósfera de vapor de agua, de los cementos portland anhidros e hidratados y en general el efecto de la carbonatación sobre los silicatos y aluminatos presentes en los cementos portland, especialmente sobre el perfil de las curvas derivatométricas de los cementos portland anhidros e hidratados. Se recogen y examinan los cambios experimentados en el doble pico al someter los cementos a la acción de diversos tratamientos y de agentes modificantes, tales como el tiempo, el CO2, la hidratación normal, las hidrataciones bajo agua a ebullición, en autoclave y en suspensión acuosa con agitación, la adición de puzolana y de fuertes proporciones de S04Ca. Se estudia y compara, asimismo, el comportamiento al análisis térmico bajo vapor de agua y al ensayo de autoclave de algunos clínkeres y cementos que presentan el doble pico en forma acusada y poco apreciable, respectivamente. De los resultados obtenidos se deducen conclusiones que explican los comportamientos experimentales observados. Las principales conclusiones se refieren a la interpretación de los picos que aparecen en las curvas derivatométricas o de velocidad de pérdida de peso de los cementos portland anhidros e hidratados, y a algunos aspectos de su carbonatación, a la probable existencia de un compuesto intermedio, consecuencia de la incompleta formación del silicato tricálcico y a la explicación de determinadas grandes expansiones producidas en el ensayo de autoclave.

  5. Cement compositions for cementing wells, allowing pressure gas-channeling in the cemented annulus to be controlled

    Energy Technology Data Exchange (ETDEWEB)

    Parcevaux, P.A.; Piot, B.M.; Vercaemer, C.J.

    1987-01-27

    The invention relates to cement compositions for cementing oil and geothermal wells. These compositions allow pressure gas-channeling to be effectively controlled up to more than about 485/sup 0/F. The compositions according to the invention comprise four essential constituents: a cement, a styrene-butadiene latex, a latex stabilizer, and water. The cement is a hydraulic cement belonging to any class among those currently used for cementing oil wells. The useful stabilizers according to the invention are anionic polyelectrolytes such as lignosulfanates and their desulfonated and/or resulfonated derivatives; sulfonated lignin-Kraft products; melamine-formaldehyde resins modified by a sulfonic acid or sulfite; formaldehyde/sulfonated naphthalene resins; or the condensation products of bi-nuclear sulfonated phenols and of formaldehyde. Preferred are the sodium salts of the condensation product of mononaphthalenesulfonic acid and of formaldehyde. The patent also includes a description of tests of various cement compositions of the invention, plus scanning electron microscope observations. 10 figs., 7 tabs.

  6. Key technology research on high strength low calcium Portland cement preparation%高强低钙硅酸盐水泥制备关键技术研究

    Institute of Scientific and Technical Information of China (English)

    刘松辉; 魏丽颖; 赵松海; 管学茂; 汪澜

    2014-01-01

    基于节能减排和应对气候变化的新要求,研究开发低钙水泥有多方面的重要意义。试验分别采用化学试剂和工业原料,运用化学分析、X-射线衍射、岩相分析等测试手段,初步探讨了高强低钙硅酸盐水泥制备关键技术。结果表明:工业原料中的微量元素能够解决高强低钙硅酸盐水泥的粉化问题;在试验设计的矿物组成和煅烧制度下,w(C2S)设计值在40%~45%,煅烧温度1400~1450℃时熟料性能最优。%Based on the new requirements of energy-saving emission reduction and climate change, research and development of low calcium cement has important meanings in many aspects. Using chemical reagent and industrial raw materials,by chemical analysis, X-ray diffraction and lithofacies analysis, key production technology of high-strength low-calcium Portland cement was discussed. The results show that the trace elements in industrial raw materials can solve the pulverization problem of high-strength low-calcium Port-land cement and in the system of mineral composition and calcination scheme, when w(C2S) design value is 40%~45%and firing tem-perature at 1400~1450℃, clinker performance will reach the best.

  7. Energetically Modified Cement (EMC) - Performance Mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Ronin, Vladimir; Elfgren, Lennart [Luleaa Univ. of Technology (Sweden). Centre for High Performance Cement

    2003-03-01

    Energetically Modified Cements, EMC, made of intensively milled cement (50%) and fillers (50%) of quartz or fly ash have been compared to blends of Ordinary Portland Cement, OPC, and fillers. The EMCs have better properties than other blends and are comparable to unblended OPC. This remarkable fact can probably be explained as follows. The grinding process reduces the size of both cement grains and fillers. This combined with the creation of micro defects gives the ground cement a very high degree of hydration. The increased early hydration and a better distribution of hydration products results in an extensive pore size refinement of the hardened binder. This pore size refinement leads to a favorably reduced permeability and diffusivity and very good mechanical properties.

  8. Energetically Modified Cement (EMC) - Performance Mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Ronin, Vladimir; Elfgren, Lennart [Luleaa Univ. of Technology (Sweden). Centre for High Performance Cement

    2003-03-01

    Energetically Modified Cements, EMC, made of intensively milled cement (50%) and fillers (50%) of quartz or fly ash have been compared to blends of Ordinary Portland Cement, OPC, and fillers. The EMCs have better properties than other blends and are comparable to unblended OPC. This remarkable fact can probably be explained as follows. The grinding process reduces the size of both cement grains and fillers. This combined with the creation of micro defects gives the ground cement a very high degree of hydration. The increased early hydration and a better distribution of hydration products results in an extensive pore size refinement of the hardened binder. This pore size refinement leads to a favorably reduced permeability and diffusivity and very good mechanical properties.

  9. CO2 Capture by Cement Raw Meal

    DEFF Research Database (Denmark)

    Pathi, Sharat Kumar; Lin, Weigang; Illerup, Jytte Boll

    2013-01-01

    The cement industry is one of the major sources of CO2 emissions and is likely to contribute to further increases in the near future. The carbonate looping process has the potential to capture CO2 emissions from the cement industry, in which raw meal for cement production could be used...... as the sorbent. Cyclic experiments were carried out in a TGA apparatus using industrial cement raw meal and synthetic raw meal as sorbents, with limestone as the reference. The results show that the CO2 capture capacities of the cement raw meal and the synthetic raw meal are comparable to those of pure limestone....... The CO2 capture capacity of limestone in the raw meal is lower than for pure limestone. The difference in the CO2 capture capacity decreases with an increase in cycle number. The calcination conditions and composition are major factors that influence the CO2 capture capacity of limestone. At 850 °C in N2...

  10. Investigation of glycerol polymerization in the clinker grinding process

    NARCIS (Netherlands)

    Parvulescu, A.N.; Rossi, M.; Della Pina, C.; Ciriminna, R.; Pagliaro, M.

    2011-01-01

    Concrete production is a large scale process that involves high energy consumption. In order to increase the sustainability of this process, the reduction of energy input is necessary. Bio-glycerol was demonstrated to be a highly efficient renewable-based additive in the grinding process for concret

  11. Destruction of DDT wastes in two preheater/precalciner cement kilns in China.

    Science.gov (United States)

    Yan, Dahai; Peng, Zheng; Karstensen, Kåre Helge; Ding, Qiong; Wang, Kaixiang; Wang, Zuguang

    2014-04-01

    The destruction of DDT formulations and DDT contaminated soil was conducted by feeding wastes into the flue gas chamber at the kiln inlet of two different preheater/precalciner cement kilns in China. The concentration of DDT, PCDD/PCDFs and HCB were measured in the flue gas of the main stack, in the solid material under baseline conditions and when feeding DDT-wastes. The destruction efficiency and the destruction and removal efficiency for DDT were in the range of 99.9335%-99.9998% and 99.9984%-99.9999%, respectively. The emissions of PCDD/PCDFs and HCB in the flue gas varied in the range of 0.0019-0.0171 ng I-TEQ/Nm(3) and 0.0064-0.0404 μg/Nm(3), respectively. The emission factor for PCDD/PCDF and HCB varied from 0.0137 to 0.0281 μg/ton and from 17.32 to 109.34 μg/ton of clinker, respectively. The concentration of PCDD/PCDFs and HCB in solid samples decreased as follows: cement kiln dust, 4.1-5 ng I-TEQ/kg and 0.70-0.71 μg/kg, respectively; >raw meal, 0.82-0.97 ng I-TEQ/kg and 0.18 μg/kg, respectively; >cement clinker, 0.09-0.22 ng I-TEQ/kg and 0.14-0.18 μg/kg, respectively. This study indicates that the feeding of DDT and POPs-wastes to the lower temperature part of a cement kiln system possibly to create a buildup of trace not-destroyed compounds in the system and might cause emissions; the technical feasibility and the environmental acceptability of this practice need to be investigated thoroughly.

  12. Petroleum Sludge as gypsum replacement in cement plants: Its Impact on Cement Strength

    Science.gov (United States)

    Benlamoudi, Ali; Kadir, Aeslina Abdul; Khodja, Mohamed

    2017-08-01

    Due to high cost of cement manufacturing and the huge amount of resources exhaustion, companies are trying to incorporate alternative raw materials or by-products into cement production so as to produce alternative sustainable cement. Petroleum sludge is a dangerous waste that poses serious imparts on soil and groundwater. Given that this sludge contains a high percentage of anhydrite (CaSO4), which is the main component of gypsum (CaSO4.2H2O), it may play the same gypsum role in strength development. In this research, a total replacement of gypsum (100%) has been substituted by petroleum sludge in cement production and has led to an increase of 28.8% in UCS values after 28 curing days. Nevertheless, the burning of this waste has emitted a considerable amount of carbon monoxide (CO) gas that needs to be carefully considered prior to use petroleum sludge within cement plants.

  13. Co-firing of refuse derived fuels with coals in cement kilns: combustion conditions for stable sintering

    Energy Technology Data Exchange (ETDEWEB)

    Haas, J.; Weber, R. [Clausthal University of Technology, Clausthal Zellerfeld (Germany)

    2010-12-15

    Usage of refuse derived fuels (RDFs) in cement clinker processes has grown considerably in the last decade. It has been demonstrated that RDFs can partially substitute fossil fuels without compromising clinker quality. The paper considers RDF properties which are essential for stabilisation of the sintering zone in the clinker burning process. An energy replacement indicator, defined as the RDF thermal input to the fossil fuel thermal input ratio, is used. Comminution of RDF to particle scales of pulverised fuel is economically not yet feasible and RDF is burnt at particle sizes in the order of several millimetres. Therefore, RDF combustion rates are orders of magnitudes smaller if compared to pulverised coal combustion rates. This shifts the flame zone downstream the rotary kiln and flame temperatures are reduced. A simple kiln combustion model has been used to examine the effects of RDF properties on sintering zone temperatures. Refuse derived fuels with calorific values below 20 MJ kg{sup -1} and coarse particle sizes burn at adiabatic temperatures below 2000{sup o}C. To compensate for this, the energy replacement ratio has to be increased to 114%. Calculations have shown several options to increase gas temperatures in sintering zones. The most effective would be the comminution of RDFs to pulverised fuel sizes. In this case, a further reduction of the RDF calorific value would be acceptable.

  14. Analysis on Impacts and Co-Abatement Effects of Implementing the Low Carb on Cement Standard

    Institute of Scientific and Technical Information of China (English)

    PANG Jun; SHI Yuan-Chang; FENG Xiang-Zhao; WU Shi-Yu; SUN Wen-Long

    2014-01-01

    Based on the MAP-CGE model, this paper simulated the impacts on the output, energy consumption and pollutant emissions of different cement production processes when implementing a low carbon cement standard in China. It also calculated the impacts on the marginal abatement cost and equilibrium price of the cement industry, and analyzed the co-abatement effects of different pollutants. The results showed that implementing the low carbon cement standard will be beneficial in promoting an upgrading of cement production processes, and strengthening the energy conservation and emission reduction in the cement industry. If there is no change in the existing technology, the cement industry will reduce SO2 emissions by 1.17 kg and NOx emissions by 4.44 kg per ton of CO2 emission reduction. Implementing low carbon cement standard can also promote NOx abatement in the cement industry. However, the cement industry will bear the abatement costs, and their equilibrium price will increase slightly.

  15. Synthesis of a Cementitious Material Nanocement Using Bottom-Up Nanotechnology Concept: An Alternative Approach to Avoid CO2 Emission during Production of Cement

    Directory of Open Access Journals (Sweden)

    Byung Wan Jo

    2014-01-01

    Full Text Available The world’s increasing need is to develop smart and sustainable construction material, which will generate minimal climate changing gas during their production. The bottom-up nanotechnology has established itself as a promising alternative technique for the production of the cementitious material. The present investigation deals with the chemical synthesis of cementitious material using nanosilica, sodium aluminate, sodium hydroxide, and calcium nitrate as reacting phases. The characteristic properties of the chemically synthesized nanocement were verified by the chemical composition analysis, setting time measurement, particle size distribution, fineness analysis, and SEM and XRD analyses. Finally, the performance of the nanocement was ensured by the fabrication and characterization of the nanocement based mortar. Comparing the results with the commercially available cement product, it is demonstrated that the chemically synthesized nanocement not only shows better physical and mechanical performance, but also brings several encouraging impacts to the society, including the reduction of CO2 emission and the development of sustainable construction material. A plausible reaction scheme has been proposed to explain the synthesis and the overall performances of the nanocement.

  16. ULTRA-LIGHTWEIGHT CEMENT

    Energy Technology Data Exchange (ETDEWEB)

    Fred Sabins

    2001-04-15

    The objective of this project is to develop an improved ultra-lightweight cement using ultralight hollow glass spheres (ULHS). Work reported herein addresses Task 1: Assess Ultra-Lightweight Cementing Problems and Task 3: Test Ultra-Lightweight Cements. Results reported this quarter include a review and summary of Halliburton Energy Services (HES) and BJ Services historical performance data for lightweight cement applications. These data are analyzed and compared to ULHS cement and foamed cement performances. Similar data is expected from Schlumberger, and an analysis of this data will be completed in the following phases of the project. Quality control testing of materials used to formulate ULHS cements in the laboratory was completed to establish baseline material performance standards. A testing protocol was developed employing standard procedures as well as procedures tailored to evaluate ULHS and foamed cement. This protocol is presented and discussed. Results of further testing of ULHS cements are presented along with an analysis to establish cement performance design criteria to be used during the remainder of the project. Finally, a list of relevant literature on lightweight cement performance is compiled for review during the next quarter.

  17. Essays of leaching in cemented products containing simulated waste from evaporator concentrated of PWR reactor; Ensaios de lixiviacao em produtos cimentados contendo rejeito simulado de concentrado do evaporador de reator PWR

    Energy Technology Data Exchange (ETDEWEB)

    Haucz, Maria Judite A.; Calabria, Jaqueline A. Almeida; Tello, Cledola Cassia O.; Candido, Francisco Donizete; Seles, Sandro Rogerio Novaes, E-mail: hauczmj@cdtn.b, E-mail: jaalmeida@cdtn.b, E-mail: tellocc@cdtn.b, E-mail: fdc@cdtn.b, E-mail: seless@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-10-26

    This paper evaluated the results from leaching resistance essays of cemented products, prepared from three distinct formulations, containing simulated waste of concentrated from the PWR reactor evaporator. The leaching rate is a parameter of qualification of solidified products containing radioactive waste and is determined in accordance with regulation ISO 6961. This procedure evaluates the capacity of transfer organic and inorganic substances presents in the waste through dissolution in the extractor medium. For the case of radioactive waste it is reached the more retention of contaminants in the cemented product, i.e.the lesser value of lixiviation rate. Therefore, this work evaluated among the proposed formulation that one which attend the criterion established in the regulation CNEN-NN-6.09

  18. INFLUENCE OF GLASS CULLET IN CEMENT PASTES

    Institute of Scientific and Technical Information of China (English)

    A.Karamberi; E.Chaniotakis; D.Papageorgiou; A.Moutsatsou

    2006-01-01

    The present study investigates glass and cement compatibility with a view to use glass as a cement replacement. Amber, flint and green glasses were chosen due to their prevalence in the Greek market as packaging materials. The factors under investigation were the pozzolanicity of the glass cullet, the hydration rate and the mechanical strength development of the cement pastes, as well as the expansion of the specimens due to alkali-silica reaction.Moreover, the potential enhancement of glass pozzolanic activity was examined. The results of the study were encouraging to show the potentiality of utilising glass cullet in cementitious products.

  19. Calzos pentagonales cementados: influencia de la velocidad de corte en la productividad y los costos//Cemented pentagonal inserts: influence of cutting speed on productivity and costs

    Directory of Open Access Journals (Sweden)

    David Machín-Valle

    2013-09-01

    Full Text Available Las herramientas de corte con sujeción mecánica (calzos o insertos son utilizadas en procesos de mecanizado de alta productividad. El objetivo del trabajo consiste en determinar la influencia de la velocidad de corte del proceso de torneado en la productividad y los costos. En el estudio se emplearon calzos pentagonales de carburo cementado de producción nacional. Como material a elaborar fueutilizado el acero Cr12Mo, utilizándose varias velocidades de corte, manteniéndose constante el avance y la profundidad, hasta alcanzar el desgaste límite del flanco del calzo (0,5 mm para obtener la ecuación que relaciona la velocidad de corte y el tiempo de vida útil del calzo. También fue establecida la influencia de la velocidad de corte sobre los tiempos de maquinado y los costos productivos respectivamente. Por último, la velocidad de corte obtenida para máxima productividad es 255.45 m/min y para el menor costo 120,03 m/min.Palabras claves: torneado, calzos pentagonales, productividad, velocidad de corte.______________________________________________________________________________AbstractCutting tools with mechanical clamping (inserts are used in high productivity machining processes. The objective of the study was to determine the influence of turning process cutting speed on productivity and costs. Cuban pentagonal cemented carbide inserts were used. The turning of Cr12Mo was performed atvarious cutting speeds and remained constant feed and depth. The insert´s flank wear behavior and the equation that relates the cutting speed and the insert life were determined. The influence of the cutting speed on machining time and production costs respectively was established too. It was determined thatthe cutting speed for maximum productivity is 255.45 m / min and for the lowest cost is 120.03 m / min.Key words: turning, pentagonal inserts, productivity, cutting speed.

  20. Fast Setting Cement - Literature Survey

    Science.gov (United States)

    1973-01-01

    materials does produce early set times and high strengths . It is re- ported, also, that the addition of 1.5 percent Ca"l 2 to clinkers contain- Ing more than...produce high strength concrete. They include addition of iron asggregate, physical treatment of clinker , ’ addition of highly reactive SiO2 or Ca0, and...Fast-Fix. The Western Co. has developed materials designated as Fast-Fix with rapid setting and high strength properties. Published data show i .1

  1. The suitability of a supersulfated cement for nuclear waste immobilisation

    Energy Technology Data Exchange (ETDEWEB)

    Collier, N.C., E-mail: nick.collier@sheffield.ac.uk [Immobilisation Science Laboratory, Department of Materials Science and Engineering, The University of Sheffield, Mappin Street, Sheffield S1 3JD (United Kingdom); Milestone, N.B. [Immobilisation Science Laboratory, Department of Materials Science and Engineering, The University of Sheffield, Mappin Street, Sheffield S1 3JD (United Kingdom); Callaghan Innovation, 69 Gracefield Road, PO Box 31310, Lower Hutt 5040 (New Zealand); Gordon, L.E. [Immobilisation Science Laboratory, Department of Materials Science and Engineering, The University of Sheffield, Mappin Street, Sheffield S1 3JD (United Kingdom); Geopolymer and Minerals Processing Group, Department of Chemical and Biomolecular Engineering, University of Melbourne, Parkville, Victoria 3010 (Australia); Ko, S.-C. [Holcim Technology Ltd, Hagenholzstrasse 85, CH-8050 Zurich (Switzerland)

    2014-09-15

    Highlights: • We investigate a supersulfated cement for use as a nuclear waste encapsulant. • High powder fineness requires a high water content to satisfy flow requirements. • Heat generation during hydration is similar to a control cement paste. • Typical hydration products are formed resulting in a high potential for waste ion immobilisation. • Paste pH and aluminium corrosion is less than in a control cement paste. - Abstract: Composite cements based on ordinary Portland cement are used in the UK as immobilisation matrices for low and intermediate level nuclear wastes. However, the high pore solution pH causes corrosion of some metallic wastes and undesirable expansive reactions, which has led to alternative cementing systems being examined. We have investigated the physical, chemical and microstructural properties of a supersulfated cement in order to determine its applicability for use in nuclear waste encapsulation. The hardened supersulfated cement paste appeared to have properties desirable for use in producing encapsulation matrices, but the high powder specific surface resulted in a matrix with high porosity. Ettringite and calcium silicate hydrate were the main phases formed in the hardened cement paste and anhydrite was present in excess. The maximum rate of heat output during hydration of the supersulfated cement paste was slightly higher than that of a 9:1 blastfurnace slag:ordinary Portland cement paste commonly used by the UK nuclear waste processing industry, although the total heat output of the supersulfated cement paste was lower. The pH was also significantly lower in the supersulfated cement paste. Aluminium hydroxide was formed on the surface of aluminium metal encapsulated in the cement paste and ettringite was detected between the aluminium hydroxide and the hardened cement paste.

  2. Development of an Improved Cement for Geothermal Wells

    Energy Technology Data Exchange (ETDEWEB)

    Trabits, George [Trabits Group, LLC, Wasilla, AK (United States)

    2015-04-20

    After an oil, gas, or geothermal production well has been drilled, the well must be stabilized with a casing (sections of steel pipe that are joined together) in order to prevent the walls of the well from collapsing. The gap between the casing and the walls of the well is filled with cement, which locks the casing into place. The casing and cementing of geothermal wells is complicated by the harsh conditions of high temperature, high pressure, and a chemical environment (brines with high concentrations of carbon dioxide and sulfuric acid) that degrades conventional Portland cement. During the 1990s and early 2000s, the U.S. Department of Energy’s Geothermal Technologies Office (GTO) provided support for the development of fly-ash-modified calcium aluminate phosphate (CaP) cement, which offers improved resistance to degradation compared with conventional cement. However, the use of CaP cements involves some operational constraints that can increase the cost and complexity of well cementing. In some cases, CaP cements are incompatible with chemical additives that are commonly used to adjust cement setting time. Care must also be taken to ensure that CaP cements do not become contaminated with leftover conventional cement in pumping equipment used in conventional well cementing. With assistance from GTO, Trabits Group, LLC has developed a zeolite-containing cement that performs well in harsh geothermal conditions (thermal stability at temperatures of up to 300°C and resistance to carbonation) and is easy to use (can be easily adjusted with additives and eliminates the need to “sterilize” pumping equipment as with CaP cements). This combination of properties reduces the complexity/cost of well cementing, which will help enable the widespread development of geothermal energy in the United States.

  3. Seismic, magnetic, and geotechnical properties of a landslide and clinker deposits, Powder River basin, Wyoming and Montana

    Science.gov (United States)

    Miller, C.H.

    1979-01-01

    Exploitation of vast coal and other resources in the Powder River Basin has caused recent, rapid increases in population and in commercial and residential development and has prompted land utilization studies. Two aspects of land utilization were studied for this report: (1) the seismic and geotechnical properties of a landslide and (2) the seismic, magnetic, and geotechnical properties of clinker deposits. (1) The landslide seismic survey revealed two layers in the slide area. The upper (low-velocity) layer is a relatively weak mantle of colluvium and unconsolidated and weathered bedrock that ranges in thickness from 3.0 to 7.5 m and has an average seismic velocity of about 390 m/s. It overlies high-velocity, relatively strong sedimentary bedrock that has velocities greater than about 1330 m/s. The low-velocity layer is also present at the other eight seismic refraction sites in the basin; a similar layer has also been reported in the Soviet Union in a landslide area over similar bedrock. The buried contact of the low- and high-velocity layers is relatively smooth and is nearly parallel with the restored topographic surface. There is no indication that any of the high-velocity layer (bedrock) has been displaced or removed. The seismic data also show that the shear modulus of the low-velocity layer is only about one-tenth that of the high-velocity layer and the shear strength (at failure) is only about one-thirtieth. Much of the slide failure is clearly in the shear mode, and failure is, therefore, concluded to be confined to the low-velocity layer. The major immediate factor contributing to landslide failure is apparently the addition of moisture to the low-velocity layer. The study implies that the low-velocity layer can be defined over some of the basin by seismic surveys and that they can help predict or delineate potential slides. Preventative actions that could then be taken include avoidance, dewatering, prevention of saturation, buttressing the toe, and

  4. PRINCIPLES OF RE-ENGINEERING METHODOLOGY FOR TECHNOLOGICAL PROCESS IN PROCESSING OF RAW MATERIAL COMPONENTS WHILE PRODUCING CEMENT AND SILICATE PRODUCTS

    Directory of Open Access Journals (Sweden)

    I. A. Busel

    2014-01-01

    necessity to modernize technological equipment used for grinding raw material components with the purpose to improve efficiency and quality, power- and resource saving. The possibility of using various grinding aids that permit to increase grinding productivity is shown in the paper. The paper studies an automation concept of the control system which used for grinding process of mineral raw material. A conceptual model for complexation of various methods grinding aids has been proposed in the paper. The paper presents methodological principles for simulation of technological process used for processing of mineral raw material while producing cement and silicate products. The parameters which are to be controlled and which are necessary for development of computer simulations of technological grinding process have been determined in the paper. The paper justifies an application of imitation simulation for creation of computer models. Methodology for imitation simulation of the technological process has been studied in the paper. The paper confirms the possibility to use analytical and probability methods. Imitation simulations of a grinding mill operation have been developed on the basis of experimental data and probability functions. The possibility of controlling technological process of raw material grinding has been demonstrated in the paper.While implementing the proposed complex of organizational and technical recommendations it is possible to increase grinding productivity up to 30-50 % and sign