WorldWideScience

Sample records for cement industry tendencias

  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. Tendencies in the energy consumption and in the carbon dioxide emissions in the Mexican cement industry; Tendencias del consumo de energia y emisiones de bioxido de carbono de la industria cementera mexicana

    Energy Technology Data Exchange (ETDEWEB)

    Ozawa M, Leticia; Sheinbaum P, Claudia [Instituto de Ingenieria UNAM, Mexico, D. F. (Mexico)

    1996-12-31

    This paper analyzes the changes occurred in the energy consumption and carbon dioxide in the Mexican cement industry. For this purpose, the energy consumption and the emissions are broken up into three types of changes that affect the energy demand of an industry: activity, structure and energy intensity. According to this analysis it is found that the Mexican cement industry has suffered an important reduction in the energy intensity as a result of the disappearance, almost complete, of the wet production process, of the increment in the production of pozzolanic cement and in the opening of new high technology industries. With respect to the intensity of carbon dioxide emissions it does not decrease at the same rate than the energy intensity due to the increased consumption of the fuel oil over the natural gas. At the end of this paper an international comparison is presented of the energy specific consumption and of its emissions. [Espanol] En este articulo se analizan los cambios ocurridos en el consumo de energia y emisiones de bioxido de carbono de la industria cementera mexicana. Para ello, se desagrega el consumo de energia y las emisiones en tres tipos de cambios que influyen en la demanda energetica de una industria: actividad, estructura, e intensidad energetica. De acuerdo con este analisis se encuentra que la industria cementera mexicana ha sufrido un importante decremento en la intensidad energetica producto de la desaparicion, casi por completo, del proceso de produccion por via humeda, del incremento en la produccion del cemento puzolanico y de la apertura de nuevas industrias con alta tecnologia. Por su parte, la intensidad en las emisiones de bioxido de carbono no disminuye a la misma tasa que la intensidad energetica debido al incremento en el uso del combustoleo sobre el gas natural. Al final del articulo se presenta una comparacion internacional del consumo especifico de energia y de las emisiones.

  3. Global Cement Industry: Competitive and Institutional Dimensions

    OpenAIRE

    Selim, Tarek; Salem, Ahmed

    2010-01-01

    The cement industry is a capital intensive, energy consuming, and vital industry for sustaining infrastructure of nations. The international cement market –while constituting a small share of world industry output—has been growing at an increasing rate relative to local production in recent years. Attempts to protect the environment in developed countries –especially Europe—have caused cement production plants to shift to countries with less stringent environmental regulations. Along with con...

  4. 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.

  5. Thoughts on the Current Cement Industry Development

    Institute of Scientific and Technical Information of China (English)

    Gan Zhihe

    2003-01-01

    According to the analysis of cement capacity andits relations with macro economy running index, the mainreasons for the present rapid development of cement capacityare the rapid development of economy and the shot up ofwhole society fixed asset investment. According to the presentspeed of economy development, cement still enjoys a po-tential increase, So here has not been an overall excessivepopularity of cement industry. The best way to prevent lowlevel repeated construction is to promote the development ofnew dry- process cement as well as try to get rid of blindness.

  6. Case Study of the California Cement Industry

    OpenAIRE

    Coito, Fred; Powell, Frank; Worrell, Ernst; Price, Lynn; Friedmann, Rafael

    2005-01-01

    California is the largest cement producing state in the U.S., accounting for between 10 percent and 15 percent of U.S. cement production and cement industry employment. The cement industry in California consists of 31 sites that consume large amounts of energy, annually: 1,600 GWh of electricity, 22 million therms of natural gas, 2.3 million tons of coal, 0.25 tons of coke, and smaller amounts of waste materials, including tires. The case study summarized in this paper focused on providi...

  7. ANALYSIS OF UNCERTAINTIES IN CEMENT INDUSTRY IN TURKEY

    OpenAIRE

    Kemal Yildirim; Omer Arioz

    2013-01-01

    Cement industry having 4,5 billion Dollars revenue and 1 billion Dollar export volume plays very important role in Turkey’s economy. Turkish cement industry is very sensitive to economic crisis and involves many uncertainties. In this study, price uncertainties, technological uncertainties, and price-technological uncertainties in Turkish cement industry were analyzed. The cement demand is mostly affected by demand to ready mixed concrete. Demand to cement is also related to the picture of co...

  8. Trends in the energy use in the Mexican industrial sector; Tendencias del uso de la energia en el sector industrial mexicano

    Energy Technology Data Exchange (ETDEWEB)

    Sheinbaum, C. [UNAM, Mexico, D. F. (Mexico); Jauregui, I. [CONAE, Mexico, D. F. (Mexico)

    1995-12-31

    This paper presents an analysis of the trends of the energy use for the industry in Mexico. For the various industrial branches (mining, construction, chemical, sugar, cement, paper and cellulose and glass) the changes in energy intensity (measured as the use of the energy divided by the aggregated value) and in the participation of the same in the industrial Internal Gross Product are presented. This is developed by means of the analysis of Laspeyress exchange indexes. It is found that in most of the industrial branches a reduction of the energy density has been originated. The reasons for the falling of this indicator are structural and of technological change nature, depending on the industrial branch. Nevertheless the classical analysis of the Laspeyress indexes is not sufficient to explain the changes occurred in the energy intensity in the Mexican industry for the last years. [Espanol] Este articulo presenta un analisis de las tendencias del uso de la energia para la industria en Mexico. Para las diversas ramas industriales (mineria, construccion, quimica, azucar, cemento, papel y celulosa y vidrio) se presentan los cambios en la intensidad energetica (medida como uso de la energia entre valor agregado) y en la participacion de las mismas en el Producto Interno Bruto (PIB) industrial. Esto se desarrolla por medio del analisis de indices de cambio de Laspeyress. Se encuentra que en la mayoria de las ramas industriales hubo una disminucion en la intensidad energetica. Las razones de la caida de este indicador son estructurales y de cambio tecnologico dependiendo de la rama industrial. Sin embargo el analisis clasico de los indices de Laspeyress es insuficiente para explicar los cambios ocurridos en la intensidad energetica de la industria mexicana para los ultimos anos.

  9. 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...

  10. Copper Slag Blended Cement: An Environmental Sustainable Approach for Cement Industry in India

    Directory of Open Access Journals (Sweden)

    Jagmeet Singh

    2016-04-01

    Full Text Available Indian cement industry is facing environmental issue of emission of carbon dioxide (CO2, a greenhouse gas. Blended cements including supplementary cementitious materials are substitute of Portland cement to reduce CO2 emission. The present paper investigates theappropriateness of copper slag (CS as supplementary cementitious material. Strength properties and hydration of mixes were determined at different replacement levels of CS with cement. Compressive, flexural and tensile strength of each mix was found out at different curing periods. The hydration of cement was investigated through X-ray diffraction (XRD. The strength test results showed that substitution of up to 20% of CS can significantly replace Portland cement.XRD test results were corresponding to strength test results. The present study encourages the utilization of CS as supplementary cementitious material to make economical and environmentally sustainable blended cement

  11. Cancer Mortality and Incidence in Cement Industry Workers in Korea

    OpenAIRE

    Koh, Dong-Hee; Kim, Tae-Woo; Jang, Seung Hee; Ryu, Hyang-Woo

    2011-01-01

    Objectives Cement contains hexavalent chromium, which is a human carcinogen. However, its effect on cancer seems inconclusive in epidemiologic studies. The aim of this retrospective cohort study was to elucidate the association between dust exposure in the cement industry and cancer occurrence. Methods The cohorts consisted of male workers in 6 Portland cement factories in Korea. Study subjects were classified into five groups by job: quarry, production, maintenance, laboratory, and office wo...

  12. Environmental health survey in asbestos cement sheets manufacturing industry

    OpenAIRE

    Ansari F; Bihari V; Rastogi S; Ashquin M; Ahmad I

    2007-01-01

    About 673 small-scale asbestos mining and milling facilities and 33 large - scale asbestos manufacturing plants, (17 asbestos-cement product manufacturing plants and 16 other than asbestos-cement product plants) are situated in India. The present study reveals the exposure of commercial asbestos (chrysotile) in the occupational as well as ambient air environment of the asbestos-cement (AC) sheets industry using membrane filter method of Bureau of Indian Standards (BIS). The fibre concentratio...

  13. Impacts of cement industries on environment and control measure

    International Nuclear Information System (INIS)

    Utilization of cement as building material is gaining more importance. Cement industries around the world are contributing in global and as well as local pollution. In Pakistan most of the cement industries are constructed in remote areas without any proper environmental impact assessment. Unawareness of peoples toward sustainable environment and due to lack of job opportunities, dwellers are demanding employment rather than clean environment from title-holder of the industry. Air pollution caused by cement industries is harmful to the human's health, spoils and erodes building surface, corrodes metals, weakens textiles, deteriorates atmospheric visibility, affects plant life and leads to ecological imbalances. To investigate environmental impact of cement industries in Pakistan, environmental conditions around and inside the five cement industries in the vicinity of Taxila city are studied. To inspect the whole scenario, air pollution control devices in these industries were also examined in detail. These industries are using Electrostatic Precipitators and Baghouses to control air pollution (dust particulates). Proper caring of these equipment is necessary for better results. Detailed study shows that emissions from their stacks and dust particulates are causing problems. Health consultants in study area are much worry about the health of workers and environmental degradation in the vicinity of these industries. The comparison of air pollution control devices shows that Baghouses are environmental friendly. Considering the field conditions it is also concluded that involvement of government and environmental pollution control agencies is much more necessary. (author)

  14. Use of alternative fuels in the Polish cement industry

    Energy Technology Data Exchange (ETDEWEB)

    Mokrzycki, Eugeniusz; Uliasz-Bochenczyk, Alicja [Polish Academy of Sciences, Mineral and Energy Economy Research Inst., Krakow (Poland); Sarna, Mieczyslaw [Lafarge Cement Polska S.A., Malogoszcz (Poland)

    2003-02-01

    Alternative fuels are made up of mixtures of different wastes, such as industrial, municipal and hazardous wastes. These fuels need to have an appropriate chemical energy content which depends on the type of components and their organic content. An industry that is particularly well suited to the employment of alternative fuels is the cement industry. There are a number of factors that promote the use of alternative fuels in cement kilns. Of these factors, the most notable are: the high temperatures developed, the appropriate kiln length, the long period of time the fuel stays inside the kiln and the alkaline environment inside the kiln. There are a number of countries that use their own alternative fuels in cement plants. These fuels have different trade names and they differ in the amounts and the quality of the selected municipal and industrial waste fractions used. The fuels used should fall within the extreme values of parameters such as: minimum heating value, maximum humidity content, and maximum content of heavy and toxic metals. Cement plants in Poland also use alternative fuels. Within the Lafarge Group, the cement plants owned by Lafarge Poland Ltd. have initiated activities directed at promoting the wider use of alternative fuels. There are a number of wastes that can be incinerated as fuel in cement plants. Some that can be mentioned are: selected combustible fractions of municipal wastes, liquid crude-oil derived wastes, car tyres, waste products derived from paint and varnish production, expired medicines from the pharmaceutical industry and others. The experience gained by the cement plants of Lafarge Cement Poland Ltd confirms that such activities are economically and ecologically beneficial. The incineration of alternative fuels in cement plants is a safe method for the utilisation of waste that is ecologically friendly and profitable for the industrial plants and society alike. (Author)

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

    OpenAIRE

    Vizcaíno-Andrés, L. M.; Sánchez-Berriel, S.; Damas-Carrera, S.; A. Pérez-Hernández; Scrivener, K. L.; Martirena-Hernández, J. F.

    2015-01-01

    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 fulf...

  16. 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).

  17. The status of energy conservation in Taiwan's cement industry

    International Nuclear Information System (INIS)

    The cement industry represents one of the most energy intensive sectors in Taiwan. Energy audits are the direct tools which are employed to help reduce energy consumption. The objectives of energy audits are to establish energy audit systems, provide on-site energy audit service and reduce production cost. This study summarized the energy savings implemented in Taiwan's cement industry; the data were obtained from the on-line Energy Declaration System in 2010. The total implemented energy savings amounted to 68,512 kilo liter of crude oil equivalent (KLOE). The energy audit group audited seven Taiwanese cement plants in 2011 and revealed an energy saving potential of 2571.6 MWh of electricity and 1002.8 KLOE of thermal energy. The total potential energy saving was 1708.5 KL of crude oil equivalent (KLOE), equivalent to a 4560 t reduction in CO2 emissions, representing the annual CO2 absorption capacity of a 122 ha forest plantation. - Highlights: • This study summarizes the energy savings implemented in Taiwan's cement industry from the on-line Energy Declaration System. • The energy audit group audited seven Taiwanese cement plants in 2011 and revealed energy saving potential was 1708.5 KLOE. • This work aims to examine what Taiwan has done and also describes the current status in cement industry. • In addition, some potential energy conservation opportunities or measures are revealed in this paper

  18. Energy Efficiency Improvement Opportunities for the Cement Industry

    OpenAIRE

    Worrell, Ernst

    2008-01-01

    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 commercial...

  19. Carbon Capture in the Cement Industry: Technologies, Progress, and Retrofitting.

    Science.gov (United States)

    Hills, Thomas; Leeson, Duncan; Florin, Nicholas; Fennell, Paul

    2016-01-01

    Several different carbon-capture technologies have been proposed for use in the cement industry. This paper reviews their attributes, the progress that has been made toward their commercialization, and the major challenges facing their retrofitting to existing cement plants. A technology readiness level (TRL) scale for carbon capture in the cement industry is developed. For application at cement plants, partial oxy-fuel combustion, amine scrubbing, and calcium looping are the most developed (TRL 6 being the pilot system demonstrated in relevant environment), followed by direct capture (TRL 4-5 being the component and system validation at lab-scale in a relevant environment) and full oxy-fuel combustion (TRL 4 being the component and system validation at lab-scale in a lab environment). Our review suggests that advancing to TRL 7 (demonstration in plant environment) seems to be a challenge for the industry, representing a major step up from TRL 6. The important attributes that a cement plant must have to be "carbon-capture ready" for each capture technology selection is evaluated. Common requirements are space around the preheater and precalciner section, access to CO2 transport infrastructure, and a retrofittable preheater tower. Evidence from the electricity generation sector suggests that carbon capture readiness is not always cost-effective. The similar durations of cement-plant renovation and capture-plant construction suggests that synchronizing these two actions may save considerable time and money. PMID:26630247

  20. Alternative fuels in cement industry; Alternativa braenslen i cementindustrin

    Energy Technology Data Exchange (ETDEWEB)

    Nyman, K.E.; Ek, R. [Finnsementti Oy, Parainen (Finland); Maekelae, K. [Finreci Oy (Finland)

    1997-10-01

    In this project the cement industry`s possibilities to replace half of the fossil fuels with waste derived fuels are investigated. Bench-scale experiments, pilot plant tests and full scale tests have been done with used tires and plastics wastes

  1. 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

  2. Development of Bulk Nanocrystalline Cemented Tungsten Carbide for Industrial Applicaitons

    Energy Technology Data Exchange (ETDEWEB)

    Z. Zak Fang, H. Y. Sohn

    2009-03-10

    This report contains detailed information of the research program entitled "Development of Bulk Nanocrystalline Cemented Tungsten Carbide Materials for Industrial Applications". The report include the processes that were developed for producing nanosized WC/Co composite powders, and an ultrahigh pressure rapid hot consolidation process for sintering of nanosized powders. The mechanical properties of consolidated materials using the nanosized powders are also reported.

  3. 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.

  4. Calcium Sulfoaluminate Eco-Cement from Industrial Waste

    OpenAIRE

    Ukrainczyk, N.; Frankoviæ Mihelj, N.; Šipušić, J.

    2013-01-01

    In this paper, the potential benefits offered by calcium sulfoaluminate cement (CSA) production from industrial wastes or by-products already present in Republic of Croatia have been addressed. A variety of industrial wastes, namely phosphogypsum (PG), coal bottom ash (BA) and electric arc furnace slag (EAFS) were used as raw materials to provide additional environmental advantages in production of CSA. Mass fraction of Ye’elimite, the principal hydraulic mineral in the prepared CSA was de...

  5. Energy economy and industrial ecology in the Brazilian cement sector; Economia de energia e ecologia industrial no setor cimenteiro brasileiro

    Energy Technology Data Exchange (ETDEWEB)

    Tavares, Marina Elisabete Espinho; Schaeffer, Roberto [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Planejamento Energetico]. E-mail: marinatavares@openlink.com.br; roberto@ppe.ufrj.br

    1999-07-01

    The article discusses the following issues of the Brazilian cement sector: the Brazilian cement main types specification, cement quantities evolution produced in Brazil from 1987 to 1997, energy conservation in the cement production process with additives, energy economy cost estimates from the utilization of additives, and several technologies energy economy cost used in the industrial sector.

  6. Polish cement industry cartel - preliminary examination of collusion existence

    Directory of Open Access Journals (Sweden)

    Sylwester Bejger

    2011-01-01

    Full Text Available The paper is devoted to a case of a cartel in Polish cement industry. Short description of the industry and characteristics of the cartel with its fundamental illegal practices, market sharing and price fixing, have been done. We focused on examination of possibility of detection of a cartel-like behavior of players in an industry on a basis of cartel markers' evaluation, using statistical data we can actually obtain. On a basis of examination of market shares of players and price/supply processes we found distinctive, theoretically motivated patterns characteristic for collusive equilibrium in an industry.

  7. 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

  8. Environmental health survey in asbestos cement sheets manufacturing industry.

    Science.gov (United States)

    Ansari, F A; Bihari, V; Rastogi, S K; Ashquin, M; Ahmad, I

    2007-01-01

    About 673 small-scale asbestos mining and milling facilities and 33 large - scale asbestos manufacturing plants, (17 asbestos-cement product manufacturing plants and 16 other than asbestos-cement product plants) are situated in India. The present study reveals the exposure of commercial asbestos (chrysotile) in the occupational as well as ambient air environment of the asbestos-cement (AC) sheets industry using membrane filter method of Bureau of Indian Standards (BIS). The fibre concentrations in 15 samples collected in the occupational environment at ingredient feeding site, sheet-producing site, fibre godown were 0.079, 0.057 and 0.078 f/cc, respectively and in five samples from surrounding ambient air at factory gate resulted fibre concentration of 0.071 f/cc. All the samples have shown fibre concentration lower than the threshold limit values (TLVs) prescribed by BIS. Morphological analysis of samples, further under phase contrast and polarized microscopy indicates the presence of chrysotile asbestos, which acts as carcinogen as well as co-carcinogen. A clinical examination of exposed subjects reveals that there was no case of clubbing, crepitation, ronchi and dyspnea on exertion; however, obstruction and restriction were 10.9 per cent and 25 per cent in exposed subjects, respectively while in control there were 12 per cent and 28 per cent, respectively. The study revealed that chrysotile asbestos is emitted in the occupational as well as ambient environment that may cause adverse health impact. PMID:21957367

  9. Utilization coke dust as fuel in the cement industry

    International Nuclear Information System (INIS)

    Utilization of coke dust available from coal carbonization plants, as a fuel in the cement industry has been undertaken and discussed in this research paper. The parameters studied include physical and chemical evaluation of the coke dust and its economic feasibility/ suitability as fuel for the cement plants. Detailed studies have been carried out on the above referred parameters. In addition a comparative study has been done to access its suitability in comparison to other fuels especially imported coal. It has been found that the coke dust contained about 66% fixed carbon, 29% ash, 4% volatile matter, 1% moisture and 0.48% sulphur. It gross calorific value was found to be 5292 Kcal/kg. The detailed analysis of coke dust ash was also performed to determine as to how its constituents will compare with the cement constituents. Keeping in view the experimental results/ data generated on the coke dust, it has been concluded that it can be quite a good substitute for imported coal. In doing so a substantial financial saving can be achieved which ranges 40-45%. (author)

  10. Environmental health survey in asbestos cement sheets manufacturing industry

    Directory of Open Access Journals (Sweden)

    Ansari F

    2007-01-01

    Full Text Available About 673 small-scale asbestos mining and milling facilities and 33 large - scale asbestos manufacturing plants, (17 asbestos-cement product manufacturing plants and 16 other than asbestos-cement product plants are situated in India. The present study reveals the exposure of commercial asbestos (chrysotile in the occupational as well as ambient air environment of the asbestos-cement (AC sheets industry using membrane filter method of Bureau of Indian Standards (BIS. The fibre concentrations in 15 samples collected in the occupational environment at ingredient feeding site, sheet-producing site, fibre godown were 0.079, 0.057 and 0.078 f/cc, respectively and in five samples from surrounding ambient air at factory gate resulted fibre concentration of 0.071 f/cc. All the samples have shown fibre concentration lower than the threshold limit values (TLVs prescribed by BIS. Morphological analysis of samples, further under phase contrast and polarized microscopy indicates the presence of chrysotile asbestos, which acts as carcinogen as well as co-carcinogen. A clinical examination of exposed subjects reveals that there was no case of clubbing, crepitation, ronchi and dyspnea on exertion; however, obstruction and restriction were 10.9 per cent and 25 per cent in exposed subjects, respectively while in control there were 12 per cent and 28 per cent, respectively. The study revealed that chrysotile asbestos is emitted in the occupational as well as ambient environment that may cause adverse health impact.

  11. Utilization of Industrial Borax Wastes (BW) for Portland Cement Production

    OpenAIRE

    ELBEYLİ, İffet YAKAR

    2004-01-01

    Industrial borax wastes (BWs) are formed as solid waste during the production of borax from tincal [Na2B4O5(OH)4.8H2O] in Bandırma, Turkey. These wastes cause different environmental problems and lead to economic losses because of high boron oxide (B2O3) content. The primary aim of this study is the removal of B2O3 from BWs and the second aim is the usage of BWs with low boron content in cement as an additive material. For this purpose, the BW was treated with water for removal of b...

  12. Sectoral Model of the Cement Industry Using Input-Output Analysis

    OpenAIRE

    Lasselle, Sarah

    2013-01-01

    This study assesses the effect CCS employment on the global warming impact of the European cement industry using Multi-Regional Input-Output Analysis.For the cement sectors of the 28 European countries studied, technology and cohort distributions were established, thermal efficiency fuel input data were collected, and the capacity turnover and evolution of CO2 emissions from cement production of each country were determined. An economic life cycle inventory of CCS implementation for cement wa...

  13. 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.

  14. 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.

  15. Screening for collusion: Evidences from the Indian cement industry

    Directory of Open Access Journals (Sweden)

    Sylwester Bejger

    2015-07-01

    Full Text Available The paper is devoted to evaluation of the econometric method applied as a part of a variance screen in collusion detection procedure. Validation is based on ex-post analysis of Indian cement industry in the 1994 - 2009 time period and comparative study of the obtained results with factual evidences of collusion at that market. The method in question is based on MS(MAR (p, q Markov switching model specification. As a result of the research we could identify variability regimes consistent with theoretical motivation of the marker and detect collusion and competition phases partly consistent with historical evidences. However promising, method had some drawbacks applied to high frequency data in the context of variance screen. We proposed some solutions for further research to overcome it.

  16. Carbon dioxide emission reduction by increased utilization of waste-derived fuels in the cement industry

    OpenAIRE

    Tokheim, Lars-André; Brevik, Per

    2007-01-01

    Considerable reductions in Norway's emissions of greenhouse gases like CO2 are required to meet the commitments of the Kyoto Protocol. CO2 emissions from cement clinker production originate from decarbonation of limestone as well as fuel combustion, and the cement plants in Norway have to comply with requirements given by the pollution control authorities via the national emissions trading system. There are several ways of reducing CO2 emissions from the cement industry. Utiliz...

  17. AIR POLLUTION AND LUNG CAPACITY OF PEOPLE LIVING AROUND THE CEMENT INDUSTRY, INDONESIA

    OpenAIRE

    Erwin Azizi Jayadipraja; Anwar Daud; Alimuddin Hamzah Assegaf; Maming

    2016-01-01

    Backgrounds: A cement industry is one of anthropogenic sources of air pollution. In polluting the air, the industry creates some dust particles, nitrogen oxide (NO2), sulfur oxide (SO2), and carbon monoxide (CO). Research Purpose: The research aimed at finding out the ambient air quality around a cement industry and relating it with the lung capacity of people living around the area. Methodology: This was a cross sectional studies by measuring the ambient air quality in the morning, noo...

  18. Toward a sustainable cement industry in 2020 : improvement of the environmental, health & safety performance

    NARCIS (Netherlands)

    2001-01-01

    This background document concentrates on technical and managerial aspects of Environmental, Health & Safety Performance (EHS) control in the cement industry. It gives an overview of options for improvement toward a sustainable cement production in 2020. Energy consumption and use of alternative fuel

  19. Toward a sustainable cement industry in 2020 : improvement of the environmental, health & safety performance

    OpenAIRE

    2001-01-01

    This background document concentrates on technical and managerial aspects of Environmental, Health & Safety Performance (EHS) control in the cement industry. It gives an overview of options for improvement toward a sustainable cement production in 2020. Energy consumption and use of alternative fuels and raw materials are included in this substudy.

  20. Technological, economic and financial prospects of carbon dioxide capture in the cement industry

    International Nuclear Information System (INIS)

    Cement is the second largest anthropogenic emission source, contributing approximately 7% of global CO2 emissions. Carbon dioxide capture and storage (CCS) technology is considered by the International Energy Agency (IEA) as an essential technology capable of reducing CO2 emissions in the cement sector by 56% by 2050. The study compares CO2 capture technologies for the cement manufacturing process and analyses the economic and financial issues in deploying CO2 capture in the cement industry. Post-combustion capture with chemical absorption is regarded as a proven technology to capture CO2 from the calcination process. Oxyfuel is less mature but Oxyfuel partial capture—which only recycles O2/CO2 gas in the precalciner—is estimated to be more economic than post-combustion capture. Carbonate looping technologies are not yet commercial, but they have theoretical advantages in terms of energy consumption. In contrast with coal-fired power plants, CO2 capture in the cement industry benefits from a higher concentration of CO2 in the flue gas, but the benefit is offset by higher SOx and NOx levels and the smaller scale of emissions from each plant. Concerning the prospects for financing cement plant CO2 capture, large cement manufacturers on average have a higher ROE (return on equity) and lower debt ratio, thus a higher discount rate should be considered for the cost analysis than in power plants. IEA estimates that the incremental cost for deploying CCS to decarbonise the global cement sector is in the range US$350–840 billion. The cost estimates for deploying state-of-the art post-combustion CO2 capture technologies in cement plants are above $60 to avoid each tonne of CO2 emissions. However, the expectation is that the current market can only provide a minority of financial support for CO2 capture in cement plants. Public financial support and/or CO2 utilisation will be essential to trigger large-scale CCS demonstration projects in the cement industry

  1. Opportunities for Energy Efficiency and Demand Response in the California Cement Industry

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, Daniel; Goli, Sasank; Faulkner, David; McKane, Aimee

    2010-12-22

    This study examines the characteristics of cement plants and their ability to shed or shift load to participate in demand response (DR). Relevant factors investigated include the various equipment and processes used to make cement, the operational limitations cement plants are subject to, and the quantities and sources of energy used in the cement-making process. Opportunities for energy efficiency improvements are also reviewed. The results suggest that cement plants are good candidates for DR participation. The cement industry consumes over 400 trillion Btu of energy annually in the United States, and consumes over 150 MW of electricity in California alone. The chemical reactions required to make cement occur only in the cement kiln, and intermediate products are routinely stored between processing stages without negative effects. Cement plants also operate continuously for months at a time between shutdowns, allowing flexibility in operational scheduling. In addition, several examples of cement plants altering their electricity consumption based on utility incentives are discussed. Further study is needed to determine the practical potential for automated demand response (Auto-DR) and to investigate the magnitude and shape of achievable sheds and shifts.

  2. 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

  3. 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.

  4. Linkage Analysis of Cement Industry in the Indonesian Economy: Input-Output Analysis

    Directory of Open Access Journals (Sweden)

    Muhammad Mirza

    2015-11-01

    Full Text Available This study aims to determine the relations of backward and forward linkages of cement industry on the various economic sectors in Indonesia. In analyzing the relations, Indonesia’s input-output table of year 2005 isusedwhich is based ontheIndonesian domestic transactions on the basis of the producer price of 175 sectors classification. The results showed that the cement industry has backward linkages to the 43 sectors (5 sectors that have the biggest backward linkage are: the coal sector, electricity and gas sector, natural gas and geothermal sectors,excavation goods and oil refining goods and has forward linkages to 15 sectors (5 sectors that have the biggest forward linkage, namely: agricultural infrastructure sector, roads, bridges and ports, goods from non-metallic materials, residential and non-residental buildings, the building sector and the installation of electricity, gas, water and communication, in the direct linkages, both backward and forward linkages of cement industry are still considered as low, and the total linkages of the cement industry has stronger association with upstream sector when compared to the downstream sector. The conditions of the backward linkages of cement industry in 2014 is assumed to be relatively the same as those in 2005, while the forward linkage in 2014 indicates a shift in the sectors that have the biggest linkage to the cement industry.

  5. 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.

  6. Analysis of Energy-Efficiency Opportunities for the Cement Industry in Shandong Province, China

    Energy Technology Data Exchange (ETDEWEB)

    Price, Lynn; Hasanbeigi, Ali; Lu, Hongyou; Wang, Lan

    2009-10-01

    China's cement industry, which produced 1,388 million metric tons (Mt) of cement in 2008, accounts for almost half of the world's total cement production. Nearly 40% of China's cement production is from relatively obsolete vertical shaft kiln (VSK) cement plants, with the remainder from more modern rotary kiln cement plants, including plants equipped with new suspension pre-heater and pre-calciner (NSP) kilns. Shandong Province is the largest cement-producing Province in China, producing 10% of China's total cement output in 2008. This report documents an analysis of the potential to improve the energy efficiency of NSP kiln cement plants in Shandong Province. Sixteen NSP kiln cement plants were surveyed regarding their cement production, energy consumption, and current adoption of 34 energy-efficient technologies and measures. Plant energy use was compared to both domestic (Chinese) and international best practice using the Benchmarking and Energy Saving Tool for Cement (BEST-Cement). This benchmarking exercise indicated an average technical potential primary energy savings of 12% would be possible if the surveyed plants operated at domestic best practice levels in terms of energy use per ton of cement produced. Average technical potential primary energy savings of 23% would be realized if the plants operated at international best practice levels. Energy conservation supply curves for both fuel and electricity savings were then constructed for the 16 surveyed plants. Using the bottom-up electricity conservation supply curve model, the cost-effective electricity efficiency potential for the studied cement plants in 2008 is estimated to be 373 gigawatt hours (GWh), which accounts for 16% of total electricity use in the 16 surveyed cement plants in 2008. Total technical electricity-saving potential is 915 GWh, which accounts for 40% of total electricity use in the studied plants in 2008. The fuel conservation supply curve model shows the total

  7. Applications of thermal energy storage in the cement industry

    Science.gov (United States)

    Jaeger, F. A.; Beshore, D. G.; Miller, F. M.; Gartner, E. M.

    1978-01-01

    In the manufacture of cement, literally trillions of Btu's are rejected to the environment each year. The purpose of this feasibility study program was to determine whether thermal energy storage could be used to conserve or allow alternative uses of this rejected energy. This study identifies and quantifies the sources of rejected energy in the cement manufacturing process, established use of this energy, investigates various storage system concepts, and selects energy conservation systems for further study. Thermal performance and economic analyses are performed on candidate storage systems for four typical cement plants representing various methods of manufacturing cement. Through the use of thermal energy storage in conjunction with waste heat electric power generation units, an estimated 2.4 x 10 to the 13th power Btu/year, or an equivalent on investment of the proposed systems are an incentive for further development.

  8. 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.

  9. Energy consumption and CO2 emissions in China's cement industry: A perspective from LMDI decomposition analysis

    International Nuclear Information System (INIS)

    We analyze the change of energy consumption and CO2 emissions in China's cement industry and its driving factors over the period 1990–2009 by applying a log-mean Divisia index (LMDI) method. It is based on the typical production process for clinker manufacturing and differentiates among four determining factors: cement output, clinker share, process structure and specific energy consumption per kiln type. The results show that the growth of cement output is the most important factor driving energy consumption up, while clinker share decline, structural shifts mainly drive energy consumption down (similar for CO2 emissions). These efficiency improvements result from a number of policies which are transforming the entire cement industry towards international best practice including shutting down many older plants and raising the efficiency standards of cement plants. Still, the efficiency gains cannot compensate for the huge increase in cement production resulting from economic growth particularly in the infrastructure and construction sectors. Finally, scenario analysis shows that applying best available technology would result in an additional energy saving potential of 26% and a CO2 mitigation potential of 33% compared to 2009. - Highlights: ► We analyze the energy consumption and CO2 emissions in China's cement industry. ► The growth of cement output is the most important driving factor. ► The efficiency policies and industrial standards significantly narrowed the gap. ► Efficiency gains cannot compensate for the huge increase in cement production. ► The potentials of energy-saving of 26% and CO2 mitigation of 33% exist based on BAT.

  10. [Cancer risk in asbestos-cement industry workers in Poland].

    Science.gov (United States)

    Szeszenia-Dabrowska, N; Wilczyńska, U; Szymczak, W

    1997-01-01

    A cohort study was carried out in order to evaluate the cancer risk in the asbestos-cement industry workers. The cohort consisted of workers employed in four asbestos-cement plants. One of those plants was established in 1924, the other three in the 1960s and 1970s. Currently only two of these plants continue their production. The plants used mainly chrysotile asbestos as well as crocidolite and amosite. Amphibolite asbestos was used before the mid-nineteen eighties in production of pressure pipes utilising about 15% of the total quantity of asbestos used. The measurements of the asbestos fibre concentration at work-sites have been taken occasionally since the mid 1980s, thus, the determination of a cumulative dose for individual persons in the cohort and the evaluation of the dose-effect relationship were not feasible. It could only be supposed that the concentrations at the preparatory work-site during first years of the plants' operation accounted for several tens fibres/cm3 in the production that employed the dry method. The cohort consisted of workers employed in the plant for at least three months between beginning of the plant during the post-war period, and 1980, that is during the period when amphibolite asbestos was in use. The retrospective observation was completed on 31 December 1991. The analysis of the death risk by causes was based on a standardized mortality ratios (SMRs) calculated using the person-years method. Statistical significance of SMRs was assessed by means of Poisson distribution one-sided test. The general population of Poland was used as the reference population to estimate the death risk. The cohort comprised 4,712 persons (3,563 males and 1,149 females). Of this number 4,500 persons (3,405 males and 1,095 females) were followed. The cohort availability were 95.5%. Male mortality, both total (473 deaths; SMR = 83) and due to malignant neoplasms (108 deaths; SMR = 86) was lower than in the general population. An excess of deaths from

  11. 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.

  12. Analysis and Optimization of Carbon Dioxide Emission Mitigation Options in the Cement Industry

    Directory of Open Access Journals (Sweden)

    Mohammed B. Shammakh

    2008-01-01

    Full Text Available The cement industry is responsible for approximately 5% of global anthropogenic carbon dioxide emissions emitting nearly 900 kg of CO2 for every 1000 kg of cement produced. Effective control strategies to mitigate these emissions are discussed and a mathematical programming model able to suggest the best cost effective strategy is outlined. Control costs consisting of operating and investment costs along with the efficiency of control options are taken into account in the model. A representative case study from the cement industry was considered in order to illustrate the use of the model in giving optimal control strategies. Efficiency improvement measures were found to be effective options for reduction targets up to 10 %. The model suggested that fuel switching and carbon capture must be considered at reduction targets higher than 10%. The cost of cement production was shown to increase dramatically with an increase in reduction target.

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

    International Nuclear Information System (INIS)

    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

  14. 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.

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

    OpenAIRE

    Gordana M Stefanović; Goran Vučković; Mirko Stojiljković; Milan B Trifunović

    2010-01-01

    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 ...

  16. An application of organizational excellence assessment: Evidence from cement industry

    Directory of Open Access Journals (Sweden)

    Hadi Pazoki Toroudi

    2015-11-01

    Full Text Available The objective of this paper is to evaluate the performance of Kiasar cement factory based on EFQM model. The study performs a survey among 26 managers and expertise and the required information is gathered in terms of five perspectives based on 23 questions arranged in Likert spectrum. Cronbakh’s α coefficient for enabling and results criteria are 0.924 and 0.950, respectively, which confirms the reliability of the questionnaire. In evaluating the data, it is revealed that employees’ scale, maintained the most difference (70.61% and processes scale, retained the least difference (52.42% from the ideal circumstances. Next, employees’ performance has maintained the most difference (90.79% and customer performance, and the customer results’ scale have kept the least difference (58.27% from the ideal situation. Kiasar cement factory has acquired 198.06 points out of 500 points of empowering scale and 164.08 points out of 500 total points of result scales. Also empowerment scales in Kiasar cement factory have acquired 39.61% of optimal score and differs from ideal circumstances around 60.39%. The results scales has acquired 32.82% of optimal score and approximately is different from ideal situation around 67.18%. The research results show that Kiasar cement factory has acquired 361.9 points out of 500 scores of EFQM.

  17. Energy Efficiency Improvement Potentials for the Cement Industry in Ethiopia

    NARCIS (Netherlands)

    Tesema, G.; Worrell, E.

    2015-01-01

    The cement sector is one of the fast growing economic sectors in Ethiopia. In 2010, it consumed 7 PJ of primary energy. We evaluate the potential for energy savings and CO2 emission reductions. We start by benchmarking the energy performance of 8 operating plants in 2010, and 12 plants under constru

  18. Energy efficiency improvement and CO2 emission reduction opportunities in the cement industry in China

    International Nuclear Information System (INIS)

    China's annual cement production (i.e., 1868 Mt) in 2010 accounted for nearly half of the world's annual cement production in the same year. We identified and analyzed 23 energy efficiency technologies and measures applicable to the processes in China's cement industry. The Conservation Supply Curve (CSC) used in this study is an analytical tool that captures both the engineering and the economic perspectives of energy conservation. Using bottom–up CSC models, the cumulative cost-effective and technical electricity and fuel savings, as well as the CO2 emission reduction potentials for the Chinese cement industry for 2010–2030 are estimated. By comparison, the total final energy saving achieved by the implementation of these 23 efficiency measures in the Chinese cement industry over 20 years (2010–2030) is equal to 30% of the total primary energy supply of Latin America or Middle East or around 71% of primary energy supply of Brazil in 2007. In addition, a sensitivity analysis with respect to the discount rate is conducted to assess its effect on the results. The result of this study gives a comprehensive and easy to understand perspective to the Chinese cement industry and policy makers about the energy efficiency potential and its associated cost. - Highlights: ► Estimation of energy saving potential in the entire Chinese cement industry. ► Development of the bottom–up technology-rich Conservation Supply Curve models. ► Discussion of different approaches for developing conservation supply curves. ► Primary energy saving over 20 years equal to 33% of primary energy of Latin America

  19. 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

  20. Recent developments in the cement industry: a comparative study between Mexico and India

    Directory of Open Access Journals (Sweden)

    Ganesh Babu Kumaran

    2008-10-01

    Full Text Available Since early twentieth century, the use of cement has become a popular and strategic product for economic growth of every country. In India as in Mexico, the first factories began in the earlier twentieth century, India is nowadays the world’s second largest producer and Mexico is the third firm in cement production, despite being the tenth world producer. The eighties have significate for both countries major structural changes in its economy, which have radically altered the structure and functioning of the cement industry and even more during the decade of the nineties. This article discusses the recent performance of the cement industry in both countries, compares the dynamics and causes that gave rise to these changes. It examines changes in the structure of domestic market in both countries and the strategies employed by large companies that operate in both, including a brief analysis of the role of transnational corporations in their development at the stage of globalization and liberalization of markets that characterizes the last two decades. Finally, it explores the great changes that make possible the growth and expansion of the cement industry during the period, based on technological change, the determinants of competitiveness and the role of economic policies in the development of industry in both countries.

  1. Potential energy savings and CO2 emissions reduction of China's cement industry

    International Nuclear Information System (INIS)

    This study analyzes current energy and carbon dioxide (CO2) emission trends in China's cement industry as the basis for modeling different levels of cement production and rates of efficiency improvement and carbon reduction in 2011–2030. Three cement output projections are developed based on analyses of historical production and physical and macroeconomic drivers. For each of these three production projections, energy savings and CO2 emission reduction potentials are estimated in a best practice scenario and two continuous improvement scenarios relative to a frozen scenario. The results reveal the potential for cumulative final energy savings of 27.1 to 37.5 exajoules and energy-related direct emission reductions of 3.2 to 4.4 gigatonnes in 2011–2030 under the best practice scenarios. The continuous improvement scenarios produce cumulative final energy savings of 6.0 to 18.9 exajoules and reduce CO2 emissions by 1.0 to 2.4 gigatonnes. This analysis highlights that increasing energy efficiency is the most important policy measure for reducing the cement industry's energy and emissions intensity, given the current state of the industry and the unlikelihood of significant carbon capture and storage before 2030. In addition, policies to reduce total cement production offer the most direct way of reducing total energy consumption and CO2 emissions. - Highlights: ► This study models output and efficiency improvements in Chinese cement industry from 2011–2030. ► Energy savings and CO2 emission reductions estimated for 3 scenarios relative to frozen scenario. ► Results reveal cumulative final energy savings potential of 27.1–37.5 EJ and 3.2–4.4 Gt CO2 reductions. ► Increasing efficiency is the most important policy for reducing cement energy and emissions intensity.

  2. HYDRATION AND PROPERTIES OF BLENDED CEMENT SYSTEMS INCORPORATING INDUSTRIAL WASTES

    Directory of Open Access Journals (Sweden)

    Heikal M.

    2013-06-01

    Full Text Available This paper aims to study the characteristics of ternary blended system, namely granulated blast-furnace slag (WCS, from iron steel company and Homra (GCB from Misr Brick (Helwan, Egypt and silica fume (SF at 30 mass % pozzolanas and 70 mass % OPC. The required water of standard consistency and setting times were measured as well as physico-chemical and mechanical characteristics of the hardened cement pastes were investigated. Some selected cement pastes were tested by TGA, DTA and FT-IR techniques to investigate the variation of hydrated products of blended cements. The pozzolanic activity of SF is higher than GCB and WCS. The higher activity of SF is mainly due to its higher surface area than the other two pozzolanic materials. On the other side, GCB is more pozzolanic than WCS due to GCB containing crystalline silica quartz in addition to an amorphous phase. The silica quartz acts as nucleating agents which accelerate the rate of hydration in addition to its amorphous phase, which can react with liberating Ca(OH2 forming additional hydration products.

  3. [A comparative study on domestic and foreign emission standards of air pollutants for cement industry].

    Science.gov (United States)

    Jiang, Mei; Li, Xiao-Qian; Ji, Liang; Zou, Lan; Wei, Yu-Xia; Zhao, Guo-Hua; Che, Fei; Li, Gang; Zhang, Guo-Ning

    2014-12-01

    The new National Emission Standard of Air Pollutants for Cement Industry (GB 4915-2013) becomes effective on Mar. 1st, 2014. It will play an important role in pollution prevention, total emission reduction, structure adjustment, and layout optimization for cement industry. Based on the research of emission standard in China, U. S., EU and Japan, the similarities and differences in the pollutant projects, control indicators, limits and means of implementation were discussed and advice was proposed, with the purpose to provide a reference for revision of emission standard, and to improve the level of environmental management and pollution control. PMID:25826950

  4. Development of a performance-based industrial energy efficiency indicator for cement manufacturing plants.

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, G.; Decision and Information Sciences

    2006-07-21

    Organizations that implement strategic energy management programs have the potential to achieve sustained energy savings if the programs are carried out properly. A key opportunity for achieving energy savings that plant managers can take is to determine an appropriate level of energy performance by comparing the plant performance with that of similar plants in the same industry. Manufacturing plants can set energy efficiency targets by using performance-based indicators. The U.S. Environmental Protection Agency (EPA), through its ENERGY STAR{reg_sign} program, has been developing plant energy performance indicators (EPIs) to encourage a variety of U.S. industries to use energy more efficiently. This report describes work with the cement manufacturing industry to provide a plant-level indicator of energy efficiency for assembly plants that produce a variety of products, including Portland cement and other specialty cement products, in the United States. Consideration is given to the role that performance-based indicators play in motivating change; the steps needed to develop indicators, including interacting with an industry to secure adequate data for an indicator; and the actual application and use of an indicator when complete. How indicators are employed in the EPA's efforts to encourage industries to voluntarily improve their use of energy is discussed as well. The report describes the data and statistical methods used to construct the EPI for cement manufacturing plants. Individual equations are presented, as are the instructions for using them in an associated Excel spreadsheet.

  5. The energy and exergy balances in the cement industry

    Energy Technology Data Exchange (ETDEWEB)

    Touil, D.; Belaadi, S. [Universite des Sciences et de la Technologie Houari Boumediene (Algeria); Bastide, J.P. [Institut National des Sciences Appliquees (INSA), 69 - Villeurbanne (France); Drissi, K. [Cimenterie de Sour-El-Ghozlane (Algeria)

    1995-12-31

    The studied combustion line of the cement factory is an assembling of a pre-heater composed by four-tiered cyclones, a rotary furnace and a cooler allowing a best control of thermal transfers. The energy conservations research in such systems requires energy and exergy balances analysis. Indeed, after having briefly recalled the exergy balances principle, the energy and exergy balances for each plant are presented. The corresponding balances allow to quantify the energy losses due to its running and to propose solutions able to reduce these losses. (O.L.). 8 refs., 2 figs., 2 tabs.

  6. An application of organizational excellence assessment: Evidence from cement industry

    OpenAIRE

    Hadi Pazoki Toroudi; Sarineh Naderi Alamdardehi; Nasim Mahjoub; Alireza Sheydaei Ardestani

    2015-01-01

    The objective of this paper is to evaluate the performance of Kiasar cement factory based on EFQM model. The study performs a survey among 26 managers and expertise and the required information is gathered in terms of five perspectives based on 23 questions arranged in Likert spectrum. Cronbakh’s α coefficient for enabling and results criteria are 0.924 and 0.950, respectively, which confirms the reliability of the questionnaire. In evaluating the data, it is revealed that employees’ scale, m...

  7. Pleural mesothelioma incidence in the population resident close to an asbestos-cement industry located in an Italian polluted site

    OpenAIRE

    Lucia, Fazzo; Menegozzo, Simona; Soggiu, Maria Eleonora; De Santis, Marco; Santoro, Michele; Cozza, Valentina; Brangi, Amelia; Menegozzo, Massimo; Comba, Pietro

    2013-01-01

    BACKGROUND. The industrial area of "Bagnoli Coroglio" in Naples municipality was defined as a "polluted site of national concern for remediation" in 2000. A steel and a cement plants and an asbestos-cement (Eternit) and a chemical industries operated in the area. AIMS. To estimate pleural mesothelioma incidence in the districts of Naples around the industrial area. METHODS. The area potentially affected by the industrial emissions was identified by modelling; environmental asbestos exposure w...

  8. Maintenance Free and Sustainable High-Level Control in Cement and Mining Industry

    DEFF Research Database (Denmark)

    Hansen, Ole Fink

    2009-01-01

    High-level control systems have been utilized in the process industry for decades, and also in cement production their use is well established. In comparison to manual control their ability to increase production and quality of end product, while reducing energy consumption and emission, is well ...

  9. On the Charges for Disposing Pollutants of Cement Industry%水泥工业排污收费

    Institute of Scientific and Technical Information of China (English)

    崔轶桢

    2015-01-01

    This paper described the governance of industry waste gas caused by cement production in cement calcinations and environment monitoring in cement production, and discussed the determination of charges for disposing pollutants of cement industry based on this.%叙述了对水泥煅烧产生水泥工业废气的治理和水泥生产的环境监测,并基于此对水泥工业排污收费的确定进行了论述。

  10. Policy Options for Encouraging Energy Efficiency Best Practices in Shandong Province's Cement Industry

    Energy Technology Data Exchange (ETDEWEB)

    Price, Lynn [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Zhou, Nan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lu, Hongyou [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sambeek, Emiel van [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Yowargana, Ping [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Shuang, Liu [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kejun, Jiang [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-07-12

    This research intends to explore possible design options for a sectoral approach in the cement sector in Shandong Province and to consider its respective advantages and disadvantages for future application. An effort has been made in this research to gather and analyze data that will provide a transparent and robust basis for development of a Business-As-Usual (BAU) scenario, maximum technology potential scenario, and ultimately a sector crediting baseline. Surveys among cement companies and discussions with stakeholders were also conducted in order to better understand the industry and local needs related to the sectoral approach.

  11. The application of CFD modelling to support the reduction of CO2 emissions in cement industry

    International Nuclear Information System (INIS)

    The cement industry is one of the leading producers of anthropogenic greenhouse gases, of which CO2 is the most significant. Recently, researchers have invested a considerable amount of time studying ways to improve energy consumption and pollutant formation in the overall cement manufacturing process. One idea involves dividing the calcination and clinkering processes into two separate furnaces. The calcination process is performed in a calciner while the clinkering process takes place in a rotary kiln. As this is new technology in the cement manufacturing process, calciners are still in the research and development phase. The purpose of this paper is to demonstrate the potential of CFD to support the design and optimization of calciners, whose use appears to be essential in reduction of CO2 emission during cement production. The mathematical model of the calcination process was developed, validated and implemented into a commercial CFD code, which was then used for the analysis. From the results obtained by these simulations, researchers will gain an in-depth understanding of all thermo-chemical reactions in a calciner. This understanding can be used to optimize the calciner's geometry, to make production more efficient, to lower pollutant formation and to subsequently reduce greenhouse gas emissions. -- Highlights: ► The potential of CO2 emissions reduction, by using a cement calciner was presented. ► When a cement calciner is used, CO2 emissions reduction of 3–4% can be achieved. ► The calcination model was developed, validated, and then used for the analysis. ► Shown method can be applied for investigation and optimization of cement calciners.

  12. A cohort study on mortality among wives of workers in the asbestos cement industry in Casale Monferrato, Italy.

    OpenAIRE

    Magnani, C; Terracini, B; Ivaldi, C; Botta, M; Budel, P; Mancini, A; Zanetti, R.

    1993-01-01

    The study investigates mortality from cancer and other diseases in a cohort of wives of asbestos cement workers in Casale Monferrato (northwest Italy). After the exclusion of women with an occupational record in the asbestos cement industry, the cohort comprised 1964 women. Their domestic exposure was estimated according to their husbands' periods of employment in the plant: 1740 had a period of domestic exposure whereas the remaining 224 married an asbestos cement worker only after he defini...

  13. Assessment of the thermal performance and energy conservation opportunities of a cement industry in Indonesia

    International Nuclear Information System (INIS)

    A simple model is presented to assess the thermal performance of a cement industry with an integrated view to improve the productivity of the plant. The model is developed on the basis of mass, energy and exergy balance and is applied to an existing Portland cement industry in Indonesia. The data obtained from industry show that the burning efficiency and the second law efficiency of the kiln system are 52.07% and 57.07% respectively. Cooler efficiency and heat recovery efficiency are 47.75% and 51.2% respectively. The unaccounted loss at kiln system was found to be 1.85% and that of cooler system was 19%. The high loss at cooler was mainly due to the convection and radiation losses from the uninsulated cooler. Irreversibility of the system was found to be about 20%, which is due to the conversion from chemical to thermal energy. The thermal energy conservation opportunities are identified. This study show that by replacing industrial diesel oil (IDO) with waste heat recovery from kiln and cooler exhaust for drying of raw meal and fuel, and preheating of combustion air, a cement industry in Indonesia can save about 1.264 x 105 US dollars per year

  14. DYMYSTIFICATION OF COMPETITIVENESS THROUGH VALUE ADDED METRIC IN INDIAN CEMENT INDUSTRY

    Directory of Open Access Journals (Sweden)

    B. M. Kanahalli

    2015-03-01

    Full Text Available Shareholder value is currently one of the most widely studied areas in finance. Since 1990s, creating sustainable shareholder value has gained strong interest among both academies as well on practitioners and is considered as a valid strategic objective for firms owing to the fact that business has become more competitive and this new environment requires a new approach to keep both stakeholder and shareholder satisfied. Generating Stable share holder value growth is not a Zero-Sum game where in shareholders prosper at the expense of other stakeholders. Here our focus in on value relevance of one of the modern performance measurement methods i.e. EVA-MVA over traditional performance measures. Hence paper is organized to demystify the competitiveness of select Indian Cement companies through value added metric for the purpose of making equity investment. Hypothesis formulated for this paper are three in number that i all profit making cement companies are uniformly making value, ii them is no difference in the performance of select cement companies in the industry as the nature of the business is same and iii there is no significant relation between change in Market value added andEconomic value added. In order to carry out the work, the major objective set is to appraise the competitiveness in Indian Cement Industry through EVA&MVAby pursuing the following sub-objectives; iTo evaluate the extent of value creation in Indian cement industry and the level to which Indian select cement companies are competitive against their counterparts. iiTo classify the select cement companies in the industry as the value creators, value destroyers, value pretenders and value victims. iiiTo offers suggestions in the light of findings. The methodology adopted for the study is as follows :- First EVAand MVAof respective companies calculated & both have been standardized through the invested capital. In fine, companies are placed in value positioning matrix to

  15. Working Capital Management And Profitability: A Study Of Selected Cement Industry In India

    OpenAIRE

    M. John Jacob

    2013-01-01

    This study aims toexaminethe working capital management and profitability: a study of selected cement industry in India. Working capital is defined as a major issue in financial decision-making given that it is being a part of savings in asset which calls for appropriate financing investment. The source of financial and economic data of the selected companies is based on the NSE (national stock exchange). Five companies are randomly selected from all listed companies in the NSE, but financial...

  16. Incidence of cancer and mortality among employees in the asbestos cement industry in Denmark.

    OpenAIRE

    Raffn, E; Lynge, E; Juel, K.; Korsgaard, B

    1989-01-01

    In a cohort study of the incidence of cancer and mortality among 7996 men and 584 women employed in the Danish asbestos cement industry between 1928 and 1984 over 99% were traced. Chrysotile asbestos was the only fibre type used until 1946, when amosite and (in 1952) crocidolite were also introduced. Chrysotile constituted 89%, amosite 10%, and crocidolite 1% of the asbestos used. During the first 25 years of manufacture the exposure levels were high, especially in areas where the asbestos wa...

  17. QUANTIFICATION OF THE DECISIONS OF CONTROL AND AUDIT IN INVENTORY MANAGEMENT IN CEMENT INDUSTRY ENTERPRISES

    OpenAIRE

    Sylwia £êgowik-Œwi¹cik

    2011-01-01

    Inventory management in enterprises of cement industry necessitates the assessment of the level of risk which is generated by production inventory. The processes of control and auditing allow for planning, monitoring and organization of inventory management in the analysed business entities. This paper is aimed at presentation of the phase of preparation of audit activities in the area of inventory and verification of model solutions for the processes of control and audit in terms of inventor...

  18. Energy Use Efficiency in Indian Cement Industry: Application of Data Envelopment Analysis and Directional Distance Function

    OpenAIRE

    Sabuj Kumar Mandal; S Madheswaran

    2009-01-01

    The present paper aims at measuring energy use efficiency in Indian cement industry and estimating the factors explaining inter-firm variations in energy use efficiency. Within the framework of production theory, Data Envelopment Analysis (DEA) and directional distance function (DDF) have been used to measure energy use efficiency. Using data from electronic CMIE PROWESS data base for the years 1989-90 through 2006-07, the study first estimates energy efficiency and then compares the energy e...

  19. Study of energy efficiency measures in cement industry; Estudo de medidas de eficiencia energetica na industria de cimento

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Roberta Ferreira Carrijo; Gorla, Filipe Debonzi [Universidade Estadual de Campinas (UNICAMP), SP (Brazil)

    2008-07-01

    Methods of energy conservation play an important role in the future energetic supply. The cement industry, being energetic intensive, is an important niche of performance of such methods. It is intended, in the present work, to estimate the impact of energy conservation through different scenarios. The projections have been realized considering both the technical (equipment efficiency) and economical (Industrial Transformation Worth - ITW) aspects of the cement sector. (author)

  20. Review of Relationship Between Increase of Capital and Shares Return in Automotive and Cement Industries at Tehran Stocks Exchange

    OpenAIRE

    Gholamhossein Gholami; Ramin Ansarian; Ali Etemadi; Hamide Rasi

    2012-01-01

    This study is intended to consider relationship between Increase of capital and Shares return in Automotive and Cement industries at Tehran Stocks Exchange. Statistical population under this study consists of any related companies to Automotive and Cement industries which were accepted in Tehran Stocks Exchange during 2005 to 2010. The Statistical population has been divided to experimental and control group, while experimental group faced with increase in capital the other group was not; 27 ...

  1. Review of Relationship between Capital and Stock Return in Automotive and Cement Industries at Tehran Stock Exchange

    OpenAIRE

    Gholamhossein Gholami; Ramin Ansarian; Ali Etemadi; Hamide Rasi

    2012-01-01

    This study is intended to consider relationship between Increase of capital and Shares return in Automotive and Cement industries at Tehran Stocks Exchange. Statistical population under this study consists of any related companies to Automotive and Cement industries which were accepted in Tehran Stocks Exchange during 2005 to 2010. The Statistical population has been divided to experimental and control group, while experimental group faced with increase in capital the other group was not; 27 ...

  2. Energetic and exergetic analysis of waste heat recovery systems in the cement industry

    International Nuclear Information System (INIS)

    In a typical cement producing procedure, 25% of the total energy used is electricity and 75% is thermal energy. However, the process is characterized by significant heat losses mainly by the flue gases and the ambient air stream used for cooling down the clinker (about 35%–40% of the process heat loss). Approximately 26% of the heat input to the system is lost due to dust, clinker discharge, radiation and convection losses from the kiln and the preheaters. A heat recovery system could be used to increase the efficiency of the cement plant and thus contribute to emissions decrease. The aim of this paper is to examine and compare energetically and exergetically, two different WHR (waste heat recovery) methods: a water-steam Rankine cycle, and an Organic Rankine Cycle (ORC). A parametric study proved that the water steam technology is more efficient than ORC in exhaust gases temperature higher than 310 °C. Finally a brief economic assessment of the most efficient solution was implemented. WHR installations in cement industry can contribute significantly in the reduction of the electrical consumptions operating cost thus being a very attractive investment with a payback period up to 5 years. - Highlights: • This paper presents waste heat recovery as a way to gain energy from the exhaust gases in a cement plant. • Water steam cycle and ORC has been analyzed for waste heat recovery. • The energetic and exergetic evaluation of the two waste heat recovery processes is presented and compared

  3. Use of industrial byproducts as alumina sources for the synthesis of calcium sulfoaluminate cements.

    Science.gov (United States)

    Pace, Maria Lucia; Telesca, Antonio; Marroccoli, Milena; Valenti, Gian Lorenzo

    2011-07-15

    Calcium sulfoaluminate (CSA) cements show some desirable environmentally friendly features that include the possibility of using several industrial byproducts as raw materials in their manufacturing process. Alumina powder, from the secondary aluminum manufacture, and anodization mud, from the production process of anodized aluminum, have proved to be suitable as partial or total substitutes for an expensive natural material like bauxite. CSA clinker generating raw mixtures, containing limestone, natural gypsum, bauxite, and/or one of the alumina-rich byproducts, were heated 2 h in a laboratory electric oven at temperatures ranging from 1150 to 1300 °C. Conversion of reactants into 4CaO·3Al(2)O(3)·SO(3) (the key component of CSA cements), evaluated using X-ray diffraction (XRD) analysis, increased with an increase of both burning temperature and byproduct concentration. When examined through differential thermogravimetric and XRD analyses, a synthetic CSA clinker (made from the raw mixture incorporating alumina powder as a total replacement of bauxite) mixed with 20% gypsum showed a hydration behavior almost similar to that of an industrial CSA cement containing the same amount of gypsum. PMID:21707122

  4. Advanced dust control techniques in cement industry electrostatic precipitator - a case study

    International Nuclear Information System (INIS)

    The case study deal with the current day problem of pollution by industrial zones in Pakistan with emphasis on the cement Industry which has been proved to be the second revenue generating hub after textile sector of the Pakistan. A pilot study into the identification and available removal Techniques of particulates from the exhaust of a cement plant clinker cooler was carried out. The objective of this work was to study the performance of the each technique in detail in the removal of a particulate with a wide range of sizes, under different operational conditions and to compare the results for collection efficiency with predictions by available theoretical models. A brief and comprehensive discussion regarding design, construction and bottlenecks of each tool has been discussed to fully ascertain it's scope and usability. First part of the study identifies the various pollutants being emitted from the chimney of a specific cement plant in Pakistan and while last portion deals with the ways to curtail these pollutants. (author)

  5. AIR POLLUTION AND LUNG CAPACITY OF PEOPLE LIVING AROUND THE CEMENT INDUSTRY, INDONESIA

    Directory of Open Access Journals (Sweden)

    Erwin Azizi Jayadipraja

    2016-05-01

    Full Text Available Backgrounds: A cement industry is one of anthropogenic sources of air pollution. In polluting the air, the industry creates some dust particles, nitrogen oxide (NO2, sulfur oxide (SO2, and carbon monoxide (CO. Research Purpose: The research aimed at finding out the ambient air quality around a cement industry and relating it with the lung capacity of people living around the area. Methodology: This was a cross sectional studies by measuring the ambient air quality in the morning, noon, and evening in four different settlements within 3 km from the cement industry. The measurement is then correlated with the FEV1 and FVC of lung capacity of people living around the area. Result: Of all four locations, three have ambient air quality (PM2.5 = 109.47 µg/Nm3, TSP = 454.7 µg/Nm3 that surpass the quality standard (PM2.5 = 65 µg/Nm3, TSP = 230 µg/Nm3. Of 241 respondents, the average level of FVC and FEV1 is respectively 1.9352 liter (SD: 0.45578 and 1.7486 liter (SD: 0.43874. Furthermore, the level of PM2.5 in the morning and at noon is respectively p=0.009 and p=0.003; the level of TSP in the morning and at noon is respectively p=0.003 and p=0.01; the level of NO2 in the morning is p=0.006; the level of SO2 in the morning, at noon and in the evening is respectively p=0.000, p=0.022, and p=0.000; and the level of CO in the morning, at noon and in the evening is respectively p=0.003, p=0.015, and p=0.024. Those levels are associated with the level of respondents’ FEV1. Moreover, the level of TSP in the morning is p=0.024; the level of SO2 in the morning and in the evening is p=0.007. These levels relate to the level of respondents’ FVC. Conclusion: The ambient air quality around a cement industry is affected by dispersion of industrial emission and of other sources which can cause some impairment to lung capacity.

  6. Biomonitoring spatial and temporal impact of atmospheric dust from a cement industry

    International Nuclear Information System (INIS)

    The objective of this work was to evaluate the spatial and temporal impact of dust-pollution in the vicinity of a cement industry, located in an area with dry climate. The spatial impact integrated over time was evaluated from the concentrations of Ca, Fe and Mg in in-situ Xanthoria parietina. The temporal pattern was assessed through one-month transplants of the lichen Ramalina canariensis. Four potential sources of atmospheric dust were evaluated: the limestone-quarry; the unpaved roads, the deposit area and the cement mill. Calcium concentration in lichens was considered the best cement-dust indicator. Different types of dust (clinker and grinded-limestone-dust) resulted in different time-patterns of Ca accumulation, which was also related with the different influence that wet and dry periods have in the lichen accumulation process. The dust pollution was found to be deposited locally and dependent on: the nature of dust particles and the volume and frequency of precipitation. - Biomonitoring Spatial and Temporal dust emissions in dry climates

  7. 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.

  8. Reaping the carbon rent: Abatement and overallocation profits in the European cement industry, insights from an LMDI decomposition analysis

    OpenAIRE

    Branger, Frédéric; Quirion, Philippe

    2014-01-01

    We analyse variations of carbon emissions in the European cement industry from 1990 to 2011, at the European level (EU 27), and at the national level for six major producers (Germany, France, Spain, United Kingdom, Italy and Poland). We apply a Log-Mean Divisia Index (LMDI) method, crossing data from three databases: the Getting the Numbers Right (GNR) database developed by the Cement Sustainability Initiative, the European Union Transaction Log (EUTL), and the Eurostat International Trade da...

  9. Critical elements in implementations of just-in-time management: empirical study of cement industry in Pakistan

    OpenAIRE

    Qureshi, Muhammad Imran; Iftikhar, Mehwish; Bhatti, Mansoor Nazir; Shams, Tauqeer; Zaman, Khalid

    2013-01-01

    In recent years, inventory management is continuous challenge for all organizations not only due to heavy cost associated with inventory holding, but also it has a great deal to do with the organizations production process. Cement industry is a growing sector of Pakistan’s economy which is now facing problems in capacity utilization of their plants. This study attempts to identify the key strategies for successful implementation of just-in-time (JIT) management philosophy on the cement indust...

  10. Investigating different factors influencing job satisfaction: A case study of cement industry

    Directory of Open Access Journals (Sweden)

    Mina Shirvani

    2013-10-01

    Full Text Available Job satisfaction plays an important role on increasing business productivity and efficiency. This paper presents an empirical investigation to study the relationship between job satisfaction and employees’ personal characteristics including gender, marital status, etc. The proposed study designs a questionnaire and distributes it among 244 out of 800 employees who worked for cement industry in Iran. The data are analyzed using different statistical tests such as t-student and analysis of variance. The results indicate that while there was not any meaningful relationship between gender and job satisfaction there was some meaningful relationship between marital status and job satisfaction.

  11. Cutting air Pollution by Improving Energy Efficiency of China's Cement Industry

    OpenAIRE

    Zhang, Shaohui; WORRELL Ernst; Crijns-graus, Wina

    2015-01-01

    In this study, the energy conservation supply curves (ECSC) combined with the GAINS (Greenhouse Gas and Air Pollution Interactions and Synergies) was used to estimate the co-benefits of energy savings on CO2 and air pollutants emission for implementation co-control options of energy efficiency measures and end-of-pipe options in the China's cement industry for the period 2011-2030. Results show the cost-effective energy saving potential (EEP1 scenario) and its costs is estimated to be 3.0 EJ ...

  12. 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

  13. Evaluating co-benefits of energy efficiency and air pollution abatement in China’s cement industry

    NARCIS (Netherlands)

    Zhang, Shaohui; Worrell, Ernst; Crijns - Graus, Wina

    2015-01-01

    China’s cement industry is the world’s largest and is one of the largest energy consuming, and GHG and air pollutant emitting industries. Actions to improve energy efficiency by best available technology can often bring co-benefits for climate change and air quality through reducing emissions of GHG

  14. Early Implementation of Large Scale Carbon Dioxide Removal Projects through the Cement Industry

    Science.gov (United States)

    Zeman, F. S.

    2014-12-01

    The development of large-scale carbon dioxide reduction projects requires high purity CO2and a reactive cation source. A project seeking to provide both of these requirements will likely face cost barriers with current carbon prices. The cement industry is a suitable early implementation site for such projects by virtue of the properties of its exhaust gases and those of waste concrete. Cement plants are the second largest source of industrial CO2 emissions, globally. It is also the second largest commodity after water, has no ready substitute and is literally the foundation of society. Finally, half of the CO2 emissions originate from process reactions rather than fossil fuel combustion resulting in higher flue gas CO2concentrations. These properties, with the co-benefits of oxygen combustion, create a favorable environment for spatially suitable projects. Oxygen combustion involves substituting produced oxygen for air in a combustion reaction. The absence of gaseous N2 necessitates the recirculation of exhaust gases to maintain kiln temperatures, which increase the CO2 concentrations from 28% to 80% or more. Gas exit temperatures are also elevated (>300oC) and can reach higher temperatures if the multi stage pre-heater towers, that recover heat, are re-designed in light of FGR. A ready source of cations can be found in waste concrete, a by-product of construction and demolition activities. These wastes can be processed to remove cations and then reacted with atmospheric CO2 to produce carbonate minerals. While not carbon negative, they represent a demonstration opportunity for binding atmospheric CO2while producing a saleable product (precipitated calcium carbonate). This paper will present experimental results on PCC production from waste concrete along with modeling results for oxygen combustion at cement facilities. The results will be presented with a view to mineral sequestration process design and implementation.

  15. Possible heavy metal residues in poultry and their products that are bred around cement industry

    Directory of Open Access Journals (Sweden)

    İsmail Erbil Ersoy

    2015-04-01

    Full Text Available Industry is an efficient tool for industrial development that is present in human lives and that mobilizes local and regional economies. When inspected from this aspect, industrial regions provide economic and social benefits for the societies. However on the other hand, they leave harmful effects to the environment and they may cause health and safety threats for communities. Mismanaged industrial regions may cause air and water pollution, noise problems and industrial accidents. One of the main purposes of this investigation is to determine the heavy metal (Pb, Cd, Cu, Cr, Co, Mo and Ni levels in the liver, thigh and chest tissues of the chickens bred around the cement factory in a residential area. It is determined that the heavy metal levels in the livers of poultries bred in these areas are quite high (P<0,01 and also in the heavy metal analyses performed, the values obtained from the samples taken from the egg, thigh and chest tissues of the poultries are specified as high (P<0,01.

  16. Preparation and properties of CSA type expansive cement using industrial by-products

    Energy Technology Data Exchange (ETDEWEB)

    Sone, J.T.; Cho, J.S. [Dankook University, Cheonan (Korea); Jeun, J.Y. [Hyundai Cement Co, Ltd., Tanyang-gun (Korea)

    2001-02-01

    3CaO{center_dot}3Al{sub 2}O{sub 3}{center_dot}CaSO{sub 4}(C{sub 4}A{sub 3}S) clinker was synthesized by using industrial by-product. The raw materials were used fly ash and blast furnace slag(water and air cooling) for Al{sub 2}O{sub 3} material, by-product gypsum for SO{sub 3} material and natural calcite for CaO material, respectively. The CSA type expansive was made by mixing C{sub 4}A{sub 3}S clinker, CaO and CaSO{sub 4}. The hydration and physical properties of ordinary portland cement substituted with 10 wt% CSA additive were investigated. The main hydration products were ettringite and Ca(OH){sub 2}. The densification and the expansion due to the formation of ettringite during hydration increased strength of compressive, tensile and flexural. But they reduced the drying shrinkage of hardened cement. (author). 19 refs., 3 tabs., 11 figs.

  17. Incidence of cancer and mortality among employees in the asbestos cement industry in Denmark

    DEFF Research Database (Denmark)

    Raffn, E; Lynge, E; Juel, K;

    1989-01-01

    In a cohort study of the incidence of cancer and mortality among 7996 men and 584 women employed in the Danish asbestos cement industry between 1928 and 1984 over 99% were traced. Chrysotile asbestos was the only fibre type used until 1946, when amosite and (in 1952) crocidolite were also...... introduced. Chrysotile constituted 89%, amosite 10%, and crocidolite 1% of the asbestos used. During the first 25 years of manufacture the exposure levels were high, especially in areas where the asbestos was handled dry. Measurements from 1948 indicate that the fibre levels may have ranged from 100 to 1600...... for men for non-malignant pulmonary diseases (O/E 1.63; 95% CI 1.33-1.98). Among the group of asbestos cement workers with first employment 1928-40 an excess risk of laryngeal cancer was found (O/E 5.50;95% CI 1.77-12.82). A total of 12 cases of pleural and one of peritoneal mesotheliomas was observed...

  18. A system dynamics model for analyzing energy consumption and CO2 emission in Iranian cement industry under various production and export scenarios

    International Nuclear Information System (INIS)

    Cement industry is one of the six energy intensive industries in Iran accounting for 15% of total energy consumption in the industrial sector. The sudden reform of energy prices in Iran is expected to have a great impact on production and energy consumption in this industry. In this paper, we present a system dynamics model to analyze energy consumption and CO2 emission in Iranian cement industry under various production and export scenarios. We consider new energy prices to estimate possible energy demand by this industry over next 20 years. The model includes demand for cement, production, energy consumption and CO2 emission in an integrated framework with emphasis on direct natural gas consumption. Producing blended cement, production using waste materials as alternative fuel, and wasted heat recovery for electricity generation in cement industry are three main corrective policies simulated and discussed herein. Simulation result show that complete removal of energy subsidy and implementation of corrective policies in the cement industry could potentially lead to reductions of 29% and 21%, respectively in natural gas and electricity consumptions and 22% reduction in CO2 emission. - Highlights: ► We have developed a system dynamics model to analyze the demand, production, energy consumption and CO2 emission of cement industry in Iran. ► Various production and export scenarios have been simulated to project the energy demand of Iranian cement industry over next 20 years. ► A causal structure is used to show how subsidy reform would affect energy consumption in the cement industry over the long term. ► Producing blended cement, using waste materials as an alternative fuel and recycling wasted heat for electricity generation are the main corrective policies discussed herein

  19. Efficiency analysis of world cement industry in presence of undesirable output: Application of data envelopment analysis and directional distance function

    International Nuclear Information System (INIS)

    CO2 emissions reduction and energy efficiency improvement are the targets of many environmental policies that aim at tackling climate change. The European Emission Trading is the best example of this engagement against climate change. Considering this framework, this paper studies the efficiency of the high energetic and CO2 emissions intensive cement production process in 21 world countries. Alternative formulations of standard data envelopment analysis models and a directional distance function approach are compared in order to detect the efficiency of the cement sector both in presence and in absence of carbon emissions. We first analyze the entire cement production process and we then concentrate on the production of clinker, a by-product of cement, that is the main responsible of CO2 emissions. Our results show that the inclusion or the exclusion of undesirable factors (CO2) influence efficiency levels as well as the investments in new technologies and the utilization of alternative fuels and raw materials in the cement and clinker production processes. - Highlights: ► The efficiency of clinker and cement production processes in 21 world countries is studied with a wide DEA analysis. ► Both desirable and undesirable production factors are considered. ► The relevance of including CO2 emissions in the study of industrial efficiency has been tested. ► Environmental and emission regulations raise efficiency levels. ► Investments in new technologies and the utilization of alternative fuels and raw materials increase efficiency.

  20. Assessment of Energy Efficiency Improvement and CO2 Emission Reduction Potentials in the Cement Industry in China

    Energy Technology Data Exchange (ETDEWEB)

    Hasanbeigi, Ali [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Morrow, William [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Masanet, Eric [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sathaye, Jayant [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Xu, Tengfang [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-06-15

    China’s annual cement production (i.e., 1,868 Mt) in 2010 accounted for nearly half of the world’s annual cement production in the same year. We identified and analyzed 23 energy efficiency technologies and measures applicable to the processes in the cement industry. The Conservation Supply Curve (CSC) used in this study is an analytical tool that captures both the engineering and the economic perspectives of energy conservation. Using a bottom-up electricity CSC model, the cumulative cost-effective electricity savings potential for the Chinese cement industry for 2010-2030 is estimated to be 251 TWh, and the total technical electricity saving potential is 279 TWh. The CO2 emissions reduction associated with cost-effective electricity savings is 144 Mt CO2 and the CO2 emission reduction associated with technical electricity saving potential is 161 Mt CO2. The fuel CSC model for the cement industry suggests cumulative cost-effective fuel savings potential of 4,326 PJ which is equivalent to the total technical potential with associated CO2 emission reductions of 406 Mt CO2. In addition, a sensitivity analysis with respect to the discount rate used is conducted to assess the effect of changes in this parameter on the results. We also developed a scenario in which instead of only implementing the international technologies in 2010-2030, we implement both international and Chinese domestic technologies during the analysis period and calculate the saving and cost of conserved energy accordingly. The result of this study gives a comprehensive and easy to understand perspective to the Chinese cement industry and policy makers about the energy efficiency potential and its associated cost.

  1. Mapping and modeling multiple benefits of energy efficiency and emission mitigation in China's cement industry at the provincial level

    NARCIS (Netherlands)

    Zhang, Shaohui; Worrell, Ernst; Crijns-Graus, Wina

    2015-01-01

    China's cement industry is the second largest energy consumer and key emitter of CO2 and air pollutants. It accounts for 7% of total energy consumption in China and 15% of CO2, 21% of PM, 4% SO2 and 10% of NOx of total emissions, respectively. Provincial disparities

  2. FOREIGN ECONOMIC ACTIVITY OF THE ENTERPRISES OF CEMENT INDUSTRY: FINAL GOODS EXPORT

    OpenAIRE

    Senotova, A.

    2011-01-01

    This article contains the basic information about the external trade situation on the Russian cement enterprises, the influence of the economic crisis, and the statistic data about the export of Russian cement production for the years of 2005-2010, provided by the cement companies and the analytical editions.

  3. Reaping the carbon rent: Abatement and overallocation profits in the European cement industry, insights from an LMDI decomposition analysis

    International Nuclear Information System (INIS)

    We analyse variations of carbon emissions in the European cement industry from 1990 to 2012, at the European level (EU 27), and at the national level for six major producers (Germany, France, Spain, the United Kingdom, Italy and Poland). We apply a Log-Mean Divisia Index (LMDI) method, cross-referencing data from three databases: the Getting the Numbers Right (GNR) database developed by the Cement Sustainability Initiative, the European Union Transaction Log (EUTL), and the Eurostat International Trade database. Our decomposition method allows seven channels of emission change to be distinguished: activity, clinker trade, clinker share, alternative fuels, thermal and electrical energy efficiency, and electricity decarbonisation. We find that, apart from a slow trend of emission reductions coming from technological improvements (first from a decrease in the clinker share, then from an increase in alternative fuels), most of the emission change can be attributed to the activity effect. Using counterfactual scenarios, we estimate that the introduction of the EU ETS brought small but positive technological abatement (2.2% ± 1.3% between 2005 and 2012). Moreover, we find that the European cement industry has gained 3.5 billion Euros of “overallocation profits”, mostly due to the slowdown of production. - Highlights: • We analyse variations of carbon emissions in the European cement industry. • We apply a Log-Mean Divisia Index (LMDI) method. • Most of the emission changes can be attributed to the activity effect. • The EU ETS brought small but positive technological abatement. • The European cement industry has gained 3.5 billion Euros of “overallocation profits”

  4. Energy Efficient Microwave Hybrid Processing of Lime for Cement, Steel, and Glass Industries

    Energy Technology Data Exchange (ETDEWEB)

    Fall, Morgana L; Yakovlev, Vadim; Sahi, Catherine; Baranova, Inessa; Bowers, Johnney G; Esquenazi\t, Gibran L

    2012-02-10

    MAT in the US lime industry. This estimate showed that 7.3 TBTU/year could be saved, with reduction of 270 MMlbs of CO2 emissions, and $29 MM/year in economic savings. Taking into account estimates for MAT implementation in the US cement industry, an additional 39 TBTU/year, 3 Blbs of CO2 and $155 MM/year could be saved. One of the main remaining barriers to commercialization of MAT for the lime and cement industries is the sheer size of production. Through this project, it was realized that a production size MAT rotary calciner was not feasible, and a different approach was adapted. The concept of a microwave post heat section located in the upper portion of the cooler was devised and appears to be a more realistic approach for MAT implementation. Commercialization of this technology will require (1) continued pilot scale calcining demonstrations, (2) involvement of lime kiln companies, and (3) involvement of an industrial microwave equipment provider. An initial design concept for a MAT post-heat treatment section was conceived as a retrofit into the cooler sections of existing lime rotary calciners with a 1.4 year payback. Retrofitting will help spur implementation of this technology, as the capital investment will be minimal for enhancing the efficiency of current rotary lime kilns. Retrofits would likely be attractive to lime manufacturers, as the purchase of a new lime kiln is on the order of a $30 million dollar investment, where as a MAT retrofit is estimated on the order of $1 million. The path for commercialization lies in partnering with existing lime kiln companies, who will be able to implement the microwave post heat sections in existing and new build kilns. A microwave equipment provider has been identified, who would make up part of the continued development and commercialization team.

  5. Reduction of soil pollution by usingwaste of the limestone in the cement industry

    Science.gov (United States)

    Muñoz, M. Cecilia Soto; Robles Castillo, Marcelo; Blanco Fernandez, David; Diaz Gonzalez, Marcos; Naranjo Lamilla, Pedro; Moore Undurraga, Fernando; Pardo Fabregat, Francisco; Vidal, Manuel Miguel Jordan; Bech, Jaume; Roca, Nuria

    2016-04-01

    In the cement manufacturing process (wet) a residue is generated in the flotation process. This builds up causing contamination of soil, groundwater and agricultural land unusable type. In this study to reduce soil and water pollution 10% of the dose of cement was replaced by waste of origin limestone. Concretes were produced with 3 doses of cement and mechanical strengths of each type of concrete to 7, 28 and 90 days were determined. the results indicate that the characteristics of calcareous residue can replace up to 10% of the dose of cement without significant decreases in strength occurs. It is noted that use of the residue reduces the initial resistance, so that the dose of cement should not be less than 200 kg of cement per m3. The results allow recommends the use of limestone waste since it has been observed decrease in soil and water contamination without prejudice construction material Keywords: Soil contamination; Limestone residue; Adding concrete

  6. Biomass use in the Dutch cement industry ENCI, Maastricht, The Netherlands

    OpenAIRE

    Junginger, H.M.

    2009-01-01

    Based in the Netherlands, ENCI is a division of HeidelbergCement active in the Benelux countries. It possesses three main production facilities in the Netherlands, of which the biggest is the integrated production plant in Maastricht. ENCI has been generating cement from Maastricht since 1926, and directly employs 212 people. There, the full cement production process is realised, as limestone is extracted from the 135-hectare quarry and burnt in a kiln to make clinker, which is then ground in...

  7. Tendencias en investigación sobre seguridad y salud laboral: Propuesta metodológica aplicada al sector de la construcción Trends in research about occupational safety and health: Methodology applied to the construction industry

    Directory of Open Access Journals (Sweden)

    Gloria Isabel Carvajal Peláez

    2009-07-01

    Full Text Available En este artículo se realiza un análisis de las tendencias en investigación sobre seguridad y salud ocupacional aplicadas al sector de la construcción. Se investigaron fuentes publicadas en inglés (1930 -2007 y se encontraron más de 250 artículos. Para clasificar la información, se propone el "ciclo riesgo accidente" formado por cinco pasos que reflejan la realidad de la seguridad laboral en la construcción. Para cada paso, se seleccionaron las publicaciones más representativas y se elaboraron árboles de evolución lógica teniendo en cuenta el contenido, grado de importancia, orden cronológico, aplicación sobre cada tema, etc. Con estos árboles, se pasa de lo general a lo particular en forma cronológica, para demostrar las tendencias actuales en investigación en seguridad y salud en la construcción y podemos concluir que la investigación en este aspecto sigue siendo escasa, tratándose de un campo lleno de oportunidades y con un futuro prometedor.This article analyzes trends in research in occupational safety and health applied to the construction industry. The sources of information published in English (1930-2007 and found more than 250 articles. In order to classify these documents, is proposed the "risk-accident cycle" composes by five steps that reflect the reality of occupational safety and health in the construction industry. For each one of them, the papers more representative were selected and later elaborated a tree of chronological evolution considering aspects such as the content, degree of importance, chronological order, application on each subject, etc. With the elaboration of these trees, show the passage of the general to the particular in chronological form, for demonstrating the actual trends in research in safety and health in the construction. As a final remark, nowadays, research in safety and health in the construction is still very limited, being a field with many opportunities and a promising future.

  8. Biomass use in the Dutch cement industry ENCI, Maastricht, The Netherlands

    NARCIS (Netherlands)

    Junginger, H.M.

    2009-01-01

    Based in the Netherlands, ENCI is a division of HeidelbergCement active in the Benelux countries. It possesses three main production facilities in the Netherlands, of which the biggest is the integrated production plant in Maastricht. ENCI has been generating cement from Maastricht since 1926, and d

  9. Commerical-Scale CO2 Capture and Sequestration for the Cement Industry

    Energy Technology Data Exchange (ETDEWEB)

    Adolfo Garza

    2010-07-28

    On June 8, 2009, DOE issued Funding Opportunity Announcement (FOA) Number DE-FOA-000015 seeking proposals to capture and sequester carbon dioxide from industrial sources. This FOA called for what was essentially a two-tier selection process. A number of projects would receive awards to conduct front-end engineering and design (FEED) studies as Phase I. Those project sponsors selected would be required to apply for Phase II, which would be the full design, construction, and operation of their proposed technology. Over forty proposals were received, and ten were awarded Phase I Cooperative Agreements. One of those proposers was CEMEX. CEMEX proposed to capture and sequester carbon dioxide (CO2) from one of their existing cement plants and either sequester the CO2 in a geologic formation or use it for enhanced oil recovery. The project consisted of evaluating their plants to identify the plant best suited for the demonstration, identify the best available capture technology, and prepare a design basis. The project also included evaluation of the storage or sequestration options in the vicinity of the selected plant.

  10. The application of the AERMOD model in the environmental health to identify the dispersion area of total suspended particulate from cement industry stacks

    Directory of Open Access Journals (Sweden)

    Erwin Azizi Jayadipraja

    2016-06-01

    Conclusions: AERMOD model can show potential exposure area from cement industry. It needs serious efforts to prevent and minimize the impact to public health. [Int J Res Med Sci 2016; 4(6.000: 2044-2049

  11. Impact of Working Capital Management on Firm’s Profitability: A Case Study of Cement Industry of Pakistan

    Directory of Open Access Journals (Sweden)

    Farrukh Shahzad

    2015-02-01

    Full Text Available The fundamental purpose behind this study is to exactly test the effect of working capital management on profitability of cement industry of Pakistan. To explore this relationship between these two, the creator gathered auxiliary information from 12 listed firms in Karachi stock exchange (KSC for the time period of 2007-2013. For this reason, in this study we utilize variable of return on assets ratio to gauge the benefit of organization and variables of CR, QR, NCA/TA, WCT and ITR as living up to expectations working capital management criteria. The consequences of the research demonstrate that there is a huge effect of the working capital management on profitability of cement industry of Pakistan. Accordingly, manager may improve the Profitability of their organizations by minimizing the inventory turnover ratio, and by diminishing working capital turnover ratio but there is no impact of expanding or diminishing the current proportion on profitability. Along these lines, the results show that through fitting working capital management the organization can expand its benefit. This study shall be helping hand for the cement industry of Pakistan in the management of their working capital in such an effective way thus, to the point that they can increase their profitability.

  12. Review of Relationship between Capital and Stock Return in Automotive and Cement Industries at Tehran Stock Exchange

    Directory of Open Access Journals (Sweden)

    Gholamhossein Gholami

    2012-04-01

    Full Text Available This study is intended to consider relationship between Increase of capital and Shares return in Automotive and Cement industries at Tehran Stocks Exchange. Statistical population under this study consists of any related companies to Automotive and Cement industries which were accepted in Tehran Stocks Exchange during 2005 to 2010. The Statistical population has been divided to experimental and control group, while experimental group faced with increase in capital the other group was not; 27 companies from first group and 12 companies of second group were chosen as statistical samples under this study. Student’s T-test and paired T-test were utilized in order to test hypotheses of this study and 19SPSS software was applied for analyzing data. Results have indicated increase in capital is not positive factor to increase in shares return. On the other hand, there is no impact of increasing in capital on shares return in the companies of Automotive and Cement industries which were accepted at Tehran Stocks Exchange.

  13. Evaluating co-benefits of energy efficiency and air pollution abatement in China’s cement industry

    International Nuclear Information System (INIS)

    Highlights: • Implementation rates of 37 EEMs are quantified for China’s cement industry. • Energy Supply Cost Curves were implemented in the GAINS model. • The economic energy saving potential is 3.0 EJ and costs is $4.1 billion in 2030. • Energy efficiency would lead to large reductions in air pollution. • The co-benefits decrease average marginal costs of EEMs by 20%. - Abstract: China’s cement industry is the world’s largest and is one of the largest energy consuming, and GHG and air pollutant emitting industries. Actions to improve energy efficiency by best available technology can often bring co-benefits for climate change and air quality through reducing emissions of GHGs and air pollutants emission. In this study, the energy conservation supply curves (ECSC) combined with the GAINS (Greenhouse Gas and Air Pollution Interactions and Synergies) was used to estimate the co-benefits of energy savings on CO2 and air pollutants emission for implementing co-control options of energy efficiency measures and end-of-pipe options in the China’s cement industry for the period 2011–2030. Results show that there are large co-benefits of improving energy efficiency and reducing emissions of CO2 and air pollutants for the China’s cement industry during the study period. The cost-effective energy saving potential (EEP1 scenario) and its costs is estimated to be 3.0 EJ and 4.1 billion $ in 2030. The technical energy savings potential (EEP2 scenario) and its costs amount to 4.2 EJ and 8.4 billion $ at the same time. Compared to the baseline scenario, energy efficiency measures can help decrease 5% of CO2, 3% of PM, 15% of SO2, and 12% of NOx emissions by 2030 in EEP1 scenario. If we do not consider costs (EEP2 scenario), energy efficiency measures can further reduce 3% of CO2, 2% of PM, 10% of SO2, and 8% of NOx by 2030. Overall, the average marginal costs of energy efficiency measures will decrease by 20%, from 1.48 $/GJ to 1.19 $/GJ, when taking into

  14. CONTRIBUTION TO THE STATISTICAL INTERPRETATION OF RAW MATERIALS FOR THE CEMENT INDUSTRY OF SPLIT

    OpenAIRE

    Miroslav Matijaca; Slavko Vujec

    1990-01-01

    Up to the last two decades cement was produced from mari called »tupina« (with about 76% CaCOj) which is an ideal mixture for cement production. Due to the quantity decrease of this raw material, cement production went on using the mixture of other members of the flysch series: limestones, marls, clay, loess, sandstones a.o. By the analysis of natural materials the CaCO^ content has mostly been proved. Therefore, knowing the correlation of oxides in mineral raw material is of special signific...

  15. Cementation in High Energy Mixer of ILW surrogate slurry. Demonstration of the process at semi-industrial scale

    International Nuclear Information System (INIS)

    To optimize the control and reliability of the slurry cementation procedure and technologies to be implemented in the future Liquid Effluent Treatment Station (STEL) at Marcoule by 2015, the French Energy Commission (CEA) has undertaken an extensive development program on a semi-industrial scale cementation pilot platform. The experimental platform comprises three levels representing a surface area of approximately 200 m2. The layout is similar to that of the industrial workshop. The upper level is for batching and introducing the various components in the mixer installed on the intermediate level. The lower level is reserved for the docking and maintenance of the canisters. A characterization laboratory also forms part of the platform. The raw materials used are those that are taken into consideration for industrial operation; the slurry used on the platform is radiologically inactive and, in particular, is prepared following the same procedure as that used in the Liquid Effluent Treatment Station (STEL) at Marcoule. The flow and time charts of the various phases of the test are described in detail, as are the parameters of the procedure applied to control the mixer in particular but also the production of the liquid cement. Specifically, thermocouples were incorporated into the container, distributed at the core, peripherally and on the wall of the drum at various levels. These acquisitions made it possible to map the drum temperatures while the cement mix sets. The containers were core-sampled in order to perform mechanical tests and appraisals. At the same time, characterizations on test specimens in the laboratory by Langavant calorimetry, Vicat setting indicator and rheometer ensure coherence of all of the results

  16. An outlook into energy consumption in large scale industries in India: The cases of steel, aluminium and cement

    International Nuclear Information System (INIS)

    All the growth-oriented sectors in a developing economy consume enormous energy in their production processes. Steel, aluminium and cement are the key manufacturing industries in India which provide inputs to various other sectors such as construction, transportation, power transmission, etc. As a result, their demand is consistently rising. These industries are heavily energy-intensive and use raw materials such as iron ore, coal, electricity, steam, and fuel oil, whose supply can act as severe production constraints over a period of time and can hinder sustainable development. Hence it becomes imperative for these industries to continuously innovate more energy efficient techniques. This paper makes a foray into the energy demand for these industries and explores the potential of any future reduction in their energy consumption. The paper offers a projection scenario for 2001-2031 (based on the MARKAL Modeling exercise for India) for possible catching up in reduction in energy consumptions in these sectors under alternative situations. The analysis suggests the existence of some plausible energy efficiency enhancing techniques in these industries. Exploring these options will definitely ensure cost effectiveness and competitiveness of these three key sectors in the global market. -- Research highlights: →Energy reduction potential exists in Indian steel, aluminium and cement sectors and can go up to 8%, 17% and 6% respectively in these sectors in 2031 if appropriate energy saving technologies are introduced and implemented. →In aluminium industry energy reduction potential is huge in fabrication stage in the production process and extensive improvement can be done in terms of energy efficiency in this stage. Cogeneration of power through waste heat recovery, change in norms in standard to take advantage of producing composite cements using more than one industrial waste, like both fly ash and slag are important required changes in Indian cement sector.

  17. Recent developments in the cement industry: a comparative study between Mexico and India

    OpenAIRE

    Ganesh Babu Kumaran; Saúl Martínez González

    2008-01-01

    Since early twentieth century, the use of cement has become a popular and strategic product for economic growth of every country. In India as in Mexico, the first factories began in the earlier twentieth century, India is nowadays the world’s second largest producer and Mexico is the third firm in cement production, despite being the tenth world producer. The eighties have significate for both countries major structural changes in its economy, which have radically altered the structure ...

  18. 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).

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

    International Nuclear Information System (INIS)

    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 oC. 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 [Ca3Cr2(SiO4)3] and a pink malayaite-based pigment [Ca(Sn,Cr)SiO5]. 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.

  20. Trabajo y salud en la industria maquiladora mexicana: una tendencia dominante en el neoliberalismo dominado Work and health in the Mexican "maquiladora" industry: a dominant trend in dominated neoliberalism

    Directory of Open Access Journals (Sweden)

    Jorge Villegas

    1997-01-01

    Full Text Available Se analizan las condiciones laborales y de salud de los trabajadores de la Industria Maquiladora de Exportación en México. Hace uso intensivo de la fuerza de trabajo mayoritariamente femenina,constituye la segunda fuente de divisas. Ilustra una tendencia dominante en el neoliberalimo respecto a condiciones de trabajo y salud, permite apreciar el impacto de la generalizada flexibilización laboral y del creciente cambio tecnológico. El panorama de los riesgos y exigencias es complejo. En la organización laboral persisten exigencias del taylorismo, los riesgos químicos son múltiples y con probables efectos que rebasan el ámbito laboral, también existen exigencias de trabajo repetitivo y posiciones incómodas. Las repercusiones en la salud muestran elevados índices de morbilidad por demanda en los servicios de seguridad social, entre 2 y 4 veces más altos que para otros trabajadores industriales. Padecimientos asociados al estrés ocupan elevado porcentaje entre los motivos de consulta. También se muestran repercusiones en las familias, el bajo peso al nacer de los hijos es un riesgo 2.8 veces mayor para obreras de la maquila respecto de otros grupos de trabajadoras. Los accidentes laborales alcanzan cifras elevada y llegando a ser la segunda causa de consulta en algunos casos. Este análisis permite identificar algunas tendencias que en la salud laboral pueden ser importantes en los próximos años para amplios grupos de trabajadores.This paper discusses health and working conditions of workers in the export-oriented "maquiladora" industry in Mexico. The work is intensive and performed mostly by women. It is the country's second largest source of foreign exchange. The "maquiladora" industry illustrates the effect of neoliberalism on working and health conditions, unveiling the impact of overall flexibilization of labor and growing technological changes. The situation for risks and demands is complex. Taylorist demands persist in work

  1. CONTRIBUTION TO THE STATISTICAL INTERPRETATION OF RAW MATERIALS FOR THE CEMENT INDUSTRY OF SPLIT

    Directory of Open Access Journals (Sweden)

    Miroslav Matijaca

    1990-12-01

    Full Text Available Up to the last two decades cement was produced from mari called »tupina« (with about 76% CaCOj which is an ideal mixture for cement production. Due to the quantity decrease of this raw material, cement production went on using the mixture of other members of the flysch series: limestones, marls, clay, loess, sandstones a.o. By the analysis of natural materials the CaCO^ content has mostly been proved. Therefore, knowing the correlation of oxides in mineral raw material is of special significance. The article discusses investigation results of the correlation between CaCO-i and other oxides of the raw material (the paper is published in Croatian.

  2. Recent growth trends and challenges in the Norwegian aquaculture industry Tendencias recientes de crecimiento y desafíos de la industria acuícola en Noruega

    Directory of Open Access Journals (Sweden)

    Asbjørn Bergheim

    2012-09-01

    Full Text Available Over the last 20 years, the Norwegian production of salmon and rainbow trout has increased by about 10% per year and will exceed 1 million MT in 2010. All on-growing after stocking in sea takes place in open cages in the fjords and along the coast, and the average cage volume has increased by about 300 times since the 1980's. Out of a total number of 4,000 cages more than 1,200 cages hold 20,000-60,000 m³. In 2005, the term 'maximum allowable biomass (MAB' was introduced and limits the highest annual production to 65 tons per 1,000 m³ licensed volume. Generally, the increasing volume and deeper cages have made the control of the fish stock more challenging. Sea lice attacks, especially in South Norway, have represented a major problem over the last three years. Reduced growth, increased mortality and lice treatment leads to significant losses and extra costs for the industry. Some recent reports indicate that increased use of wrasses in the cages improved the situation in the summer 2010 compared to the previous year. Extensive vaccinating and strict regulations regarding handling, etc. usually result in effective protection against diseases, but still there may occur regional outbreaks of serious diseases, such as pancreas disease (PD and infectious salmon anaemia (ISA. Attacks of sea lice and escape of salmon and trout from fish farms are considered to be among the main reasons for the strongly reduced wild stocks of sea trout and a reduced return of salmon spawners in the fjords and along the coast of southwest Norway.Durante los últimos 20 anos, la producción de salmón y trucha arcoiris en Noruega se ha incrementado en un 10% al ano y sobrepasará 1 millón de toneladas para el 2010. Todo el proceso de "engorda" ocurre en balsas-jaulas emplazadas en los fiordos y zonas costeras. El volumen promedio de una balsa-jaula se ha incrementado en un 300% desde sus inicios en 1980. En un universo de 4,000 balsas-jaulas se tiene que más de 1

  3. Long-term model-based projections of energy use and CO2emissions from the global steel and cement industries

    OpenAIRE

    van Ruijven, Bas J.; van Vuuren, Detlef P.; Boskaljon, Willem; Neelis, Maarten L.; Saygin, Deger; Martin K. Patel

    2016-01-01

    This paper presents a global simulation-model for the steel and cement industries. The model covers the full modelling chain from economic activity, to materials consumption, trade, technology choice, production capacity, energy use and CO2emissions. Without climate policy, the future projections based on the SSP2 scenario show a rapid increase in the consumption of steel and cement over the next few decades, after which demand levels are projected to stabilize. This implies that over the sce...

  4. Incorporating environmental co-benefits into climate policies: A regional study of the cement industry in China

    International Nuclear Information System (INIS)

    Highlights: • First study on the co-benefits of mitigation measures in the cement sector in China. • We evaluate the economic value of damage of various pollutants at local level. • We evaluate 18 energy-saving technologies for 31 provinces in cement sector. • The value for the co-benefits ranged from 3 $/t CO2 to 39 $/t CO2. • The large spatial variations may justify stringent targets for richer provinces. - Abstract: We analyzed the impacts of incorporating local air quality improvement and environmental co-benefits into the climate policy and mitigation technology assessment of the cement sector in China. Local air quality can benefit from reducing greenhouse gas emissions, which consequently lowers abatement costs and strengthens the cost-effectiveness of mitigation technologies. We used a simplified approach to estimate environmental damage factors due to air pollution at the sub-national level in China. The calculated economic costs of environmental damage due to PM10, NOx, and SO2 were 7,714 $/t, 1,006 $/t, and 902 $/t, respectively. These values vary among the provinces. We found that most energy-saving technologies in the cement industry will create significant co-benefits, ranging from 3 $/t CO2 to 39 $/t CO2 at the national level; however, a tradeoff for carbon capture and storage (CCS) and energy-saving technologies also resulted with increased electricity consumption. Large spatial variations of co-benefits can be gained at the sub-national level and justify the enactment of more stringent climate policies in the wealthier regions in China

  5. Secondary fuels in cement plants: application to other industrial sectors; Les co-combustibles en cimenterie: perspectives dans d'autres secteurs industriels

    Energy Technology Data Exchange (ETDEWEB)

    Guigues, A. [Scori, 78 - Plaisir (France)

    2003-06-01

    The cement industry is a big user of energy: the production of one ton of cement requires 90 kg of fuel and 100 kWh of electricity, i.e. 30 % of the production costs with conventional fuels. Since 25 years, French cement producers utilize also the energy of waste materials, representing about 27 % of the energy requirements for the whole French cement industry; however, some plants hit a substitution level higher than 50 %. Lafarge, Calcia and Vicat have jointly set up a company to purchase and manage special wastes to be used as secondary fuels in their plants. These fuels should be compatible with the cement quality and the regulations concerning pollution as well as personnel and vicinity safety and health. These materials are: used tires, plastics, abattoirs wastes, greases, chemical and pharmaceutical residues, oils, etc. Numerous research works have been undertaken in collaboration with state entities and cement specialists to satisfy all necessary requirements. This experience could be used in other industries provided that a similar approach be undertaken concerning the destruction of organic components and the cleaning systems be able to treat the exhaust gases. Naturally, all corresponding authorizations have to be obtained from the state authorities. (author)

  6. Application of thermal energy storage in the cement industry. Final report, September 1977--March 1978

    Energy Technology Data Exchange (ETDEWEB)

    Jaegr, F.A.; Beshore, D.G.; Miller, F.M.; Gartner, E.M.

    1978-10-01

    In the manufacture of cement, literally trillions of Btu's are rejected to the environment each year. The purpose of this feasibility study program was to determine whether thermal energy storage could be used to conserve or allow alternative uses of this rejected energy. This study identifies and quantifies the sources of rejected energy in the cement manufacturing process, establishes use of this energy, investigates various storage system concepts, and selects energy conservation systems for further study. Thermal performance and economic analyses are performed on candidate storage systems for four typical cement plants representing various methods of manufacturing cement. Through the use of thermal energy storage in conjunction with waste heat electric power generation units, an estimated 2.4 x 10/sup 13/ Btu/year, or an equivalent of 4.0 x 10/sup 6/ barrels of oil per year, can be conserved. Attractive rates of return on investment of the proposed systems are an incentive for further development.

  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. Efficiency modeling of solidification/stabilization of multi-metal contaminated industrial soil using cement and additives

    International Nuclear Information System (INIS)

    Highlights: → We assess the feasibility of using soil S/S for industrial land reclamation. → Retarders, accelerators, plasticizers were used in S/S cementitious formulation. → We proposed novel S/S efficiency model for multi-metal contaminated soils. - Abstract: In a laboratory study, formulations of 15% (w/w) of ordinary Portland cement (OPC), calcium aluminate cement (CAC) and pozzolanic cement (PC) and additives: plasticizers cementol delta ekstra (PCDE) and cementol antikorodin (PCA), polypropylene fibers (PPF), polyoxyethylene-sorbitan monooleate (Tween 80) and aqueous acrylic polymer dispersion (Akrimal) were used for solidification/stabilization (S/S) of soils from an industrial brownfield contaminated with up to 157, 32,175, 44,074, 7614, 253 and 7085 mg kg-1 of Cd, Pb, Zn, Cu, Ni and As, respectively. Soils formed solid monoliths with all cementitious formulations tested, with a maximum mechanical strength of 12 N mm-2 achieved after S/S with CAC + PCA. To assess the S/S efficiency of the used formulations for multi-element contaminated soils, we propose an empirical model in which data on equilibrium leaching of toxic elements into deionized water and TCLP (toxicity characteristic leaching procedure) solution and the mass transfer of elements from soil monoliths were weighed against the relative potential hazard of the particular toxic element. Based on the model calculation, the most efficient S/S formulation was CAC + Akrimal, which reduced soil leachability of Cd, Pb, Zn, Cu, Ni and As into deionized water below the limit of quantification and into TCLP solution by up to 55, 185, 8750, 214, 4.7 and 1.2-times, respectively; and the mass transfer of elements from soil monoliths by up to 740, 746, 104,000, 4.7, 343 and 181-times, respectively.

  9. Efficiency modeling of solidification/stabilization of multi-metal contaminated industrial soil using cement and additives

    Energy Technology Data Exchange (ETDEWEB)

    Voglar, Grega E. [RDA - Regional Development Agency Celje, Kidriceva ulica 25, 3000 Celje (Slovenia); Lestan, Domen, E-mail: domen.lestan@bf.uni-lj.si [Agronomy Department, Centre for Soil and Environmental Science, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana (Slovenia)

    2011-08-30

    Highlights: {yields} We assess the feasibility of using soil S/S for industrial land reclamation. {yields} Retarders, accelerators, plasticizers were used in S/S cementitious formulation. {yields} We proposed novel S/S efficiency model for multi-metal contaminated soils. - Abstract: In a laboratory study, formulations of 15% (w/w) of ordinary Portland cement (OPC), calcium aluminate cement (CAC) and pozzolanic cement (PC) and additives: plasticizers cementol delta ekstra (PCDE) and cementol antikorodin (PCA), polypropylene fibers (PPF), polyoxyethylene-sorbitan monooleate (Tween 80) and aqueous acrylic polymer dispersion (Akrimal) were used for solidification/stabilization (S/S) of soils from an industrial brownfield contaminated with up to 157, 32,175, 44,074, 7614, 253 and 7085 mg kg{sup -1} of Cd, Pb, Zn, Cu, Ni and As, respectively. Soils formed solid monoliths with all cementitious formulations tested, with a maximum mechanical strength of 12 N mm{sup -2} achieved after S/S with CAC + PCA. To assess the S/S efficiency of the used formulations for multi-element contaminated soils, we propose an empirical model in which data on equilibrium leaching of toxic elements into deionized water and TCLP (toxicity characteristic leaching procedure) solution and the mass transfer of elements from soil monoliths were weighed against the relative potential hazard of the particular toxic element. Based on the model calculation, the most efficient S/S formulation was CAC + Akrimal, which reduced soil leachability of Cd, Pb, Zn, Cu, Ni and As into deionized water below the limit of quantification and into TCLP solution by up to 55, 185, 8750, 214, 4.7 and 1.2-times, respectively; and the mass transfer of elements from soil monoliths by up to 740, 746, 104,000, 4.7, 343 and 181-times, respectively.

  10. Evaluation of energy saving potential in China's cement industry using the Asian-Pacific Integrated Model and the technology promotion policy analysis

    International Nuclear Information System (INIS)

    Much of China's cement industry still uses outdated kilns and other inefficient technologies, which are obstacles to improving energy efficiency. Huge improvements in energy consumption intensity can be made by improving this technology. To evaluate the potential for energy-saving and CO2 emissions reduction in China's cement industry between 2010 and 2020, a model was developed based on the Asian-Pacific Integrated Model (AIM). Three scenarios (S1, S2 and S3) were developed to describe future technology policy measures in relation to the development of the cement industry. Results show that scenario S3 would realize the potential for CO2 emissions mitigation of 361.0 million tons, accounting for 25.24% of the predicted emissions, with an additional energy saving potential of 39.0 million tons of coal equivalent by 2020. Technology promotion and industrial structure adjustment are the main measures that can lead to energy savings. Structural adjustment is the most important approach to reduce the CO2 emissions from the cement industry; the resulting potential for CO2 emissions reduction will be increasingly large, even exceeding 50% after 2016. - Highlights: • We evaluate the effectiveness of energy savings and emission reductions in China's cement industry via the AIM/end-use model. • Three scenarios are simulated to project the potential for energy savings and emission reductions over the next decade. • Structural adjustment and technology promotion are both key approaches for energy conservation. • Structural adjustment is the most important approach to reduce the CO2 emissions from the cement industry

  11. Cr(VI) removal in acidic aqueous solution using iron-bearing industrial solid wastes and their stabilisation with cement.

    Science.gov (United States)

    Singh, I B; Singh, D R

    2002-01-01

    In this study, iron-bearing industrial solid wastes iron filings, ETP sludge of steel and red mud of aluminium industries; were used for Cr(VI) removal at pH 3. A complete removal of Cr(VI) was found for initial 10 mg 1(-1) of 100 ml solutions in the presence of 2.5 g iron filings, 8 g ETP sludge and 10 g red mud for up to one hour of shaking at room temperature. After Cr(VI) removal, inclusion of chromium on the reacted iron filing surface was demonstrated by EDAX analysis. Leachability of chromium and iron from the reacted wastes was determined by using Toxicity Characteristics Leaching Procedure (TCLP). This test showed a very low level of leachability of chromium as Cr(III) and iron from the reacted wastes. To minimise their leachability further, Cr(VI)-reacted solid wastes were stabilised with Portland cement in their 3:1 ratio. Leachability tests of stabilised wastes by TCLP indicated a considerable decrease in leachability of chromium and iron compared with the that of reacted wastes alone. To explore the possibility of utilisation in building materials, bricks of cement-mixed Cr(VI)-reacted wastes were made and their comprehensive strength, durability and leachability under immersion conditions were measured. PMID:11918404

  12. Ranking of Companies based on TOPSIS-DEA Approach Methods (Case Study of Cement Industry in Tehran Stock Exchange

    Directory of Open Access Journals (Sweden)

    Ali Mansory

    2014-08-01

    Full Text Available Ranking options has always been the main issue for managers. There are a lot of qualitative and quantitative approaches for ranking. However most of the approaches for separating and ranking corporations in stock market are less reliable and the results obtained will be invalid. While the evaluation obtained merely through qualitative or quantitative approaches alone, the advantages of integration will be ignored. Thus logically the efficiency of result will be questionable. Thus in this paper the advantages of qualitative and quantitative approaches are integrated which in turn bring about more precision in values of input and output indices. Hence in this paper the approaches, TOPSIS & DEA, have been introduced to rate active companies in cement industry accepted in Tehran stock market. The approach adopted in this paper is applicable and carried out during 2006-2011 and the population of the research includes accepted companies in stock market in cement industry (28 companies and at the end a precise ranking of the companies is presented by integrattive techniques.

  13. Tendencias organizacionales de las empresas.

    Directory of Open Access Journals (Sweden)

    Derlisiret Rincón M.

    2002-01-01

    Full Text Available El propósito de este trabajo es analizar la evolución de los modelos organizacionales utilizados por las empresas durante los siglos XX y XXI, a la vez que se intenta establecer las posibles tendencias para las empresas del futuro. Para ello, se caracterizan los modelos con base en la clasificación correspondiente a las visiones: mecanicista, naturista y ecologista de la organización. En tal sentido, se realiza una investigación descriptiva-documental a partir de la revisión de importantes aportes sobre las nuevas formas organizacionales, evolución y principios de las empresas. Los resultados revelan que la supervivencia de una empresa en contextos turbulentos como los actuales dependerá de variables como: rapidez, calidad, eficiencia, espontaneidad, desestandarización, flexibilidad e innovación. Se concluye que la tendencia es a la ausencia de estructuras organizacionales, formales y rígidas.

  14. An Experimental Investigation of Partial Replacement of Cement by Industrial Waste (Hypo Sludge

    Directory of Open Access Journals (Sweden)

    Mr.R.Balamurugan

    2014-04-01

    Full Text Available Concrete is strength and tough material but it is porous material also which interacts with the surrounding environment. The durability of concrete depends largely on the movement of water and gas enters and moves through it. To produce low cost concrete by blending various ratios of cement with hypo sludge & to reduce disposal and pollution problems due to hypo sludge it is most essential to develop profitable building materials from hypo sludge. To make good quality paper limited number of times recycled Paper fibers can be used which produces a large amount of solid waste. The innovative use of hypo sludge in concrete formulations as a supplementary cementations material was tested as an alternative to traditional concrete.

  15. Individual asbestos exposure: smoking and mortality--a cohort study in the asbestos cement industry.

    OpenAIRE

    Neuberger, M.; Kundi, M

    1990-01-01

    A historical prospective cohort study comprised all persons employed from 1950 to 1981 for at least three years in the oldest asbestos cement factory in the world. From 2816 persons eligible for the study, record based estimates and measurements of dust and fibres and histories of smoking based on interviews were used to calculate individual exposures over time. After observation of 51,218 person-years and registration of 540 deaths, underlying causes of death for this cohort were compared wi...

  16. Measures for emission reduction in asbestos-cement industry and methods for emission and immission measurement

    Energy Technology Data Exchange (ETDEWEB)

    Teichert, U.

    Emissions of asbestos fine dust connected with asbestos cement are possible during: production, processing in plants, installing at the construction site and weathering of products. Main sources for possible emissions during production are: supply of asbestos, diffuse sources, exhaust air from filter units, and waste disposal. In former times the asbestos bags reached the plant rather damaged but today the asbestos is supplied in a pressed state, in dust-tight plastic bags piled up on palettes without damage.

  17. Case study: improvement of performance of cement industry rotary kilns by using a solid radiotracers

    International Nuclear Information System (INIS)

    In the present report, residence time distribution (RTD) of the cement blended raw meal has been determined by the use of 7,4x108 Bq (20 mCi) of La 40 as a dust radioactive tracer in the chemical form of La2O3. Five scintillation detector were installed alongside the kiln. Analysis and interpretation of response curves were made to draw conclusions about the improvement of the rotary kiln performance

  18. Influence of Environmentally Friendly and High-Efficiency Composite Additives on Pulverized Coal Combustion in Cement Industry

    Directory of Open Access Journals (Sweden)

    Zhiyong Wang

    2016-01-01

    Full Text Available 4 kinds of chemical reagents and 3 kinds of industrial wastes were selected as burning additives for 2 kinds of coals in cement industry. The work focused on the replacement of partial chemical reagents by industrial wastes, which not only reduced the cost and took full advantage of industrial wastes, but also guaranteed the high combustion efficiency and removed the NOX and SO2 simultaneously. The experiments were carried out in DTF. The combustion residues were analyzed by SEM and XRD. The results showed that the burnout rate was increased after adding the additives; meanwhile, the NOX and SO2 release concentration were reduced, but the degree of action varied for different additives and coals. The substitute of chemical reagents by industrial wastes was very effective; overall, the cold-rolled iron oxide worked better than others; the particles surface was tougher and the peaks of crystalline phase were lower than raw coal, which indicated that the additives played good roles in combustion process.

  19. Macro economy regulation and control and cement industry development%宏观经济调控与水泥工业发展

    Institute of Scientific and Technical Information of China (English)

    蒋明麟

    2004-01-01

    Our national economy kept comparatively rapid increase last year with good development trend of benefit, aped and vigor. But there were also some new contradiction and unstable and unhealthy factors.Cement industry also showed strong development trend. Since 21st century, the average increase rate of cement output has been 10.86%. Our new type of dry process and equipment development, design and manufacture has made great progress and successfully developed set technical equipment of 5000t/d,8000t/d and lO000t/d that has been put into production. Their main technical and economic index has reached advanced level of that of same production line in the world. But there are also prominent problems to be solved in cement industry.The State Council made resolute decision to take a series of pertinent measures of regulation and control consecutively starting from second half of 2003 and the practice showed this decision making was timely,correct and valid.We should realize the task of macro regulation and control is till very heavy. As to how to promote industry structure regulation and industry technique progress of cement industry and further enforce enterprise competitive power through macro economy regulation and control, the author raised suggestion from several aspects as follows.

  20. Asphalt cement poisoning

    Science.gov (United States)

    Asphalt; Pavement ... The substances in asphalt that can be harmful are: Hydrocarbons Industrial glues Industrial solvents Tar ... Asphalt is found in: Road paving materials Roofing materials Tile cements Asphalt may also be used for ...

  1. Mining and geologic characterization of calcareous resources for the cement industry in Uruguay

    International Nuclear Information System (INIS)

    The main objective of this work was the study of geological and mining potential that Uruguay has on limestone rocks rich in calcium and poor in magnesium and silica, which are considered primary requirements suitable for the manufacture of cement. The results obtained allow defining four major regions of the country that although do not include all occurrences of calcareous rocks, they do not constitute the most important areas concerning: rock quality, higher volumes and improved extraction possibilities. The areas are: Queguay, Minas, Carape and Treinta y tres

  2. 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.

  3. Implementation of industrial waste ferrochrome slag in conventional and low cement castables: Effect of calcined alumina

    Directory of Open Access Journals (Sweden)

    Pattem Hemanth Kumar

    2014-12-01

    Full Text Available A new class of conventional and low-cement ferrochrome slag-based castables were prepared from 40 wt.% ferrochrome slag and 45 wt.% calcined bauxite. Rest fraction varied between high alumina cement (HAC acting as hydraulic binder and calcined alumina as pore filling additive. Standard ASTM size briquettes were prepared for crushing and bending strengths evaluation, and the samples were then subjected to firing at 800, 1100 and 1300 °C for a soaking period of 3 h. The microstructure and refractory properties of the prepared castables have been investigated using X-ray diffraction (XRD, scanning electron microscopy (SEM, cold crushing strength, modulus of rupture and permanent linear changes (PLCs test. Castables show good volume stability (linear change <0.7% at 1300 °C. The outcomes of these investigations were efficacious and in accordance with previously reported data of similar compositions. High thermo-mechanical and physico-chemical properties were attained pointing out an outstanding potential to increase the refractory lining working life of non-recovery coke oven and reheating furnaces.

  4. The use of by-products from metallurgical and mineral industries as filler in cement-based materials.

    Science.gov (United States)

    Moosberg, Helena; Lagerblad, Björn; Forssberg, Eric

    2003-02-01

    This investigation has been made in order to make it possible to increase the use of by-products in cement-based materials. Use of by-products requires a screening procedure that will reliably determine their impact on concrete. A test procedure was developed. The most important properties were considered to be strength development, shrinkage, expansion and workability. The methods used were calorimetry, flow table tests, F-shape measurements, measurements of compressive and flexural strength and shrinkage/expansion measurements. Scanning electron microscopy was used to verify some results. Twelve by-products were collected from Swedish metallurgical and mineral industries and classified according to the test procedure. The investigation showed that the test procedure clearly screened out the materials that can be used in the production of concrete from the unsuitable ones. PMID:12667016

  5. 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

  6. Improving the CO2 performance of cement, part III : The relevance of industrial symbiosis and how to measure its impact

    OpenAIRE

    Ammenberg, Jonas; Baas, Leo; Eklund, Mats; Feiz, Roozbeh; Helgstrand, Anton; Marshall, Richard

    2015-01-01

    Cement production contributes to extensive CO2 emissions. However, the climate impact can vary significantly between different production systems and different types of cement products. The market is dominated by ordinary Portland cement, which is based on primary raw materials and commonly associated with combustion of vast amounts of fossil fuels. Therefore, the production of Portland cement can be described as a rather linear process. But there are alternative options, for example, involvi...

  7. Flash calcination of kaolinite rich clay and impact of process conditions on the quality of the calcines: A way to reduce CO2 footprint from cement industry

    DEFF Research Database (Denmark)

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

    2016-01-01

    Use of properly calcined kaolinite rich clay (i.e., metakaolin) to offset part of CO2-intensive clinkers not only reduces CO2 footprint from cement industry but also improves the performance of concrete. However, calcination under inappropriately high temperatures or long retention times may...

  8. Long-term model-based projections of energy use and CO2emissions from the global steel and cement industries

    NARCIS (Netherlands)

    Van Ruijven, Bas J.; Van Vuuren, Detlef P.; Boskaljon, Willem; Neelis, Maarten L.; Saygin, Deger; Patel, Martin K.

    2016-01-01

    This paper presents a global simulation-model for the steel and cement industries. The model covers the full modelling chain from economic activity, to materials consumption, trade, technology choice, production capacity, energy use and CO2emissions. Without climate policy, the future projections ba

  9. Lime mud from cellulose industry as raw material in cement mortars

    Directory of Open Access Journals (Sweden)

    Modolo, R. C.E.

    2014-12-01

    Full Text Available This study reports the use of lime mud (LM in cement-based-mortars. Lime mud is a waste generated in the production of cellulose by the kraft mill process. It is mainly composed of CaCO3, a small amount of magnesium carbonate and other trace minerals. Mortars were prepared by adding different amounts of LM (10, 20 and 30% by weight of cement in dry weight. The mortar compositions were evaluated through rheology and flow table measurements, assuring that all the samples exhibited adequate conditions for testing in both equipments. The hardened state properties were also evaluated through mechanical strengths at 7, 28 and 90 days of curing. Following a waste management solution perspective, this work intend to provide a general evaluation of LM application in cement based mortars, looking at both fresh and hardened properties in order to guarantee that the final application requirements are not hindered.Este estudio revela el uso de lodo de carbonato (LM en morteros de cemento. El LM es un residuo compuesto principalmente por CaCO3 generado en la producción de pasta de papel por el método Kraft. Los morteros se prepararon a partir de la adición de diferentes niveles de LM (10, 20 y 30% en peso de cemento en peso seco. Las composiciones de los morteros fueron caracterizadas através de mediciones de reología de mesa y de flujo, asegurando que las muestras exhibían condiciones adecuadas para su caracterización en ambos equipamientos. Las propiedades en estado endurecido también se evaluaron através de resistencias mecánicas a los 7, 28 y 90 días de cura. Con objeto de gestión de residuos, este trabajo tiene la intención de proporcionar una visión general de la aplicación de LM en los morteros, haciendo hincapié en las propiedades con el fin de garantizar que los requisitos para su aplicación final no se vean obstaculizados.

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

    International Nuclear Information System (INIS)

    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 226Ra, 232Th and 40K 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 226Ra, 232Th and 40K 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 laterite and 51.1±18.2, 23.2±1.2 and 258.4±15.3 Bq kg-1, respectively in clinker. The radium equivalent activities (Raeq), external hazard index (Hex), internal hazard index (Hin), absorbed dose rate in air (D) and annual effective dose rate (Eeff) 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. (authors)

  11. Implementation of industrial waste ferrochrome slag in conventional and low cement castables: Effect of microsilica addition

    Directory of Open Access Journals (Sweden)

    Pattem Hemanth Kumar

    2014-06-01

    Samples with decreasing cement content 15–05 wt.% were formulated in combination of both slag and calcined bauxite as matrix components. Effects of varying 0–10 wt.% microsilica as a micro-fine additive in these castables were investigated in this work. Pore filling properties of microsilica improved apparent porosity and bulk density. Phase analysis through X-ray diffraction techniques demonstrates successful formation of spinel and mullite crystalline phases. Mechanical behavior was evaluated through cold crushing strength and residual cold crushing strength after five consecutive water quenching cycles. Scanning electron microscopy measurements were carried out in order to better understand the packing density and reaction mechanisms of fired castables. Slag containing castables portrays good thermal properties such as thermal shock resistance, permanent linear change and pyrometric cone equivalent.

  12. Disposal of historically contaminated soil in the cement industry and the evaluation of environmental performance.

    Science.gov (United States)

    Li, Yeqing; Zhang, Jiang; Miao, Wenjuan; Wang, Huanzhong; Wei, Mao

    2015-09-01

    Approximately 400000t of DDTs/HCHs-contaminated soil (CS) needed to be co-processed in a cement kiln with a time limitation of 2y. A new pre-processing facility with a "drying, grinding and DDTs/HCHs vaporizing" ability was equipped to meet the technical requirements for processing cement raw meal and the environmental standards for stack emissions. And the bottom of the precalciner with high temperatures >1000°C was chosen as the CS feeding point for co-processing, which has rarely been reported. To assess the environmental performance of CS pre- and co-processing technologies, according to the local regulation, a test burn was performed by independent and accredited institutes systematically for determination of the clinker quality, kiln stack gas emissions and destruction efficiency of the pollutant. The results demonstrated that the clinker was of high quality and not adversely affected by CS co-processing. Stack emissions were all below the limits set by Chinese standards. Particularly, PCDD/PCDF emissions ranged from 0.0023 to 0.0085ngI-TEQNm(-3). The less toxic OCDD was the peak congener for CS co-processing procedure, while the most toxic congeners (i.e. 2,3,7,8-TeCDD, 1,2,3,7,8-PeCDD and 2,3,4,7,8-PeCDD) remained in a minor proportion. Destruction and removal efficiency (DRE) and destruction efficiency (DE) of the kiln system were better than 99.9999% and 99.99%, respectively, at the highest CS feeding rate during normal production. To guarantee the environmental performance of the system the quarterly stack gas emission was also monitored during the whole period. And all of the results can meet the national standards requirements. PMID:25966458

  13. Solid recovered fuels in the cement industry--semi-automated sample preparation unit as a means for facilitated practical application.

    Science.gov (United States)

    Aldrian, Alexia; Sarc, Renato; Pomberger, Roland; Lorber, Karl E; Sipple, Ernst-Michael

    2016-03-01

    One of the challenges for the cement industry is the quality assurance of alternative fuel (e.g., solid recovered fuel, SRF) in co-incineration plants--especially for inhomogeneous alternative fuels with large particle sizes (d95⩾100 mm), which will gain even more importance in the substitution of conventional fuels due to low production costs. Existing standards for sampling and sample preparation do not cover the challenges resulting from these kinds of materials. A possible approach to ensure quality monitoring is shown in the present contribution. For this, a specially manufactured, automated comminution and sample divider device was installed at a cement plant in Rohožnik. In order to prove its practical suitability with methods according to current standards, the sampling and sample preparation process were validated for alternative fuel with a grain size >30 mm (i.e., d95=approximately 100 mm), so-called 'Hotdisc SRF'. Therefore, series of samples were taken and analysed. A comparison of the analysis results with the yearly average values obtained through a reference investigation route showed good accordance. Further investigations during the validation process also showed that segregation or enrichment of material throughout the comminution plant does not occur. The results also demonstrate that compliance with legal standards regarding the minimum sample amount is not sufficient for inhomogeneous and coarse particle size alternative fuels. Instead, higher sample amounts after the first particle size reduction step are strongly recommended in order to gain a representative laboratory sample. PMID:26759433

  14. Industrial Ecology and Development of Production Systems : Analysis of the CO2  Footprint of Cement

    OpenAIRE

    Feiz, Roozbeh

    2014-01-01

    This research is an attempt to create a comprehensive assessment framework for identifying and assessing potential improvement options of cement production systems. From an environmental systems analysis perspective, this study provides both an empirical account and a methodological approach for quantifying the CO2 footprint of a cement production system. An attributional Life Cycle Assessment (LCA) is performed to analyze the CO2 footprint of several products of a cement production system in...

  15. 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.

  16. Analysis of the parameters affecting energy consumption of a rotary kiln in cement industry

    International Nuclear Information System (INIS)

    In this study, the effects of refractory bricks and formation of anzast layer on the specific energy consumption of a rotary kiln are investigated. Thermodynamic analysis of the kiln is performed to achieve effective and efficient energy management scheme. Actual data, which are taken from a cement plant located in Gaziantep, Turkey, are used in numerical calculations to obtain energy balance for the system. It is calculated that 12.5 MW of energy is lost from the surface of the kiln which accounts for the 11.3% of the total energy input to the unit. The specific energy consumption for clinker production is determined to be 3735.45 kJ/kg clinker. The formation of anzast layer and the use of high quality magnesia spinel and high alumina refractory bricks provide 7.27% reduction in energy consumption corresponding to a saving of 271.78 MJ per ton of clinker production. It is recognized that the anzast layer has an important role for durability of the refractory bricks and heat transfer out of the kiln. The applications prevent the emission of 1614.48 tons of CO2 per year to the atmosphere. - Highlights: •We analyzed a rotary kiln and investigated the first law and second law efficiency values. •Performance assessment of a kiln indicates that the burning process involves energy and exergy losses. •The anzast layer affect the efficiency and production capacity of the kiln. •The specific energy consumption for clinker production is determined

  17. Industrial symbiosis for improving the CO2-performance of cement production : Final report of the CEMEX-Linköping University industrial ecology project, 2011

    OpenAIRE

    Ammenberg, Jonas; Feizaghaii, Roozbeh; Helgstrand, Anton; Eklund, Mats; Baas, Leenard

    2011-01-01

    This report contains information about a research project lead by researchers from Environmental Technology and Management at Linköping University in Sweden. It has been conducted in cooperation with staff from the global cement company CEMEX. The study has been focused on three cement plants in the western parts of Germany, referred to as CEMEX Cluster West. They form a kind of work alliance, together producing several intermediate products and final products. One of the plants is a cement p...

  18. NO{sub x} formation in cement industry clinker kilns; Formacao de NO{sub x} em fornos rotativos de producao de clinquer da industria do cimento

    Energy Technology Data Exchange (ETDEWEB)

    Signoretti, Valdir Tesche; Silva, Rogerio Jose da [Universidade Federal de Itajuba (UNIFEI), MG (Brazil)], e-mail: valdirsg@unifei.edu.br, e-mail: rogeriojs@unifei.edu.br

    2006-07-01

    This work estimates the concentration of pollutant Nox generated in the process of combustion of petroleum coke and tires in rotary kiln for clinker production in the cement industry. Using a mixture of petroleum coke and tires in the burning process, the No{sub x} and CO emissions will be evaluated in kilns with precalciner with tertiary air. The emissions will be analyzed in this installation type still considering the staging combustion as a form of reduction of the Nox emissions. The proposed model is based on the knowledge of the chemical species concentrations involved in the chemical equilibrium and also in the knowledge of the reaction kinetics of Nox and CO formation in the combustion process. It is also done in this work a revision on No{sub x}, So{sub x} and CO concerning issues related to their formation and presenting the main controlling technologies of these pollutants used in the cement industry. (author)

  19. Refuse derived fuel (RDF) plasma torch gasification as a feasible route to produce low environmental impact syngas for the cement industry

    OpenAIRE

    López-Sabirón, Ana M.; Fleiger, Kristina; Schäfer, Stefan; Antoñanzas, Javier; Irazustabarrena, Ane; Aranda-Usón, Alfonso; Ferreira, Germán A.

    2015-01-01

    Plasma torch gasification (PTG) is currently researched as a technology for solid waste recovery. However, scientific studies based on evaluating its environmental implications considering the life cycle assessment (LCA) methodology are lacking. Therefore, this work is focused on comparing the environmental effect of the emissions of syngas combustion produced by refuse derived fuel (RDF) and PTG as alternative fuels, with that related to fossil fuel combustion in the cement industry. To obta...

  20. GESTIÓN HUMANA: TENDENCIAS Y PERSPECTIVAS

    Directory of Open Access Journals (Sweden)

    JUAN GUILLERMO SALDARRIAGA RÍOS

    2008-01-01

    Full Text Available En este artículo se hace referencia a las tendencias y las perspectivas de gestión humana que se imponen en el mundo en la actualidad y que, a su manera, pretenden optimizar la administración del personal de la organización y contribuir al desarrollo e incremento de la productividad y la competitividad. Mediante la realización de un Estado del Arte se logran determinar algunas de las tendencias más relevantes en la actualidad y se concluye que, cada vez con mayor fuerza, dichas tendencias se sustentan en discursos que pretenden "rescatar" al ser humano dentro de la organización, lo que no necesariamente se traduce en los procesos de gestión humana que se realizan en las organizaciones nacionales e internacionales.

  1. Cement industry structure adjustment and macro regulation and control%水泥结构调整与宏观调控

    Institute of Scientific and Technical Information of China (English)

    牛建国

    2004-01-01

    This article recalled the background of our national economy development in 2003, namely our GDP increase, total amount of import and export,industrial increase scale all reached quite high level and at the same time showed such problems like excessive large fixed assets investment scale and coal, electricity, oil, transport and price in economic operation.The article further expounds on the principle, stress and measure of macro regulation and control as well as the good trend of our general national economy operation in the first half of this year.This article also made introduction about relative state policy concerning cement industry development.

  2. Nuevas tendencias en digitalización

    OpenAIRE

    Díaz, Jose Luis

    2009-01-01

    [ES] En esta presentación se explica las nuevas tendencias de digitalización en Servicio Móvil. En concreto las causas de digitalización, así como su proceso y las tecnologías utilizadas para la digitalización.

  3. 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

  4. 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

  5. Barium aluminate cement: its application

    International Nuclear Information System (INIS)

    The technology of manufacturing barium aluminate cement from barium sulfate and alumina, using a rotary kiln for firing the clinker is described. The method of granulation of the homogenized charge was used. Conditions of using the ''to mud'' method in industry were indicated. The physical and chemical properties of barium aluminate cement are determined and the quality of several batches of cement prepared on a semi-industrial scale and their suitability for making highly refractory concretes are tested. The optimal composition of the concretes is determined as a function of the mixing water and barium aluminate cement contents. Several experimental batches of concretes were used in the linings of furnaces in the steel industry. The suitability of these cements for use in fields other than steelmaking is examined. It is established that calcium aluminate cement has certain limited applications

  6. Lung function reduction and chronic respiratory symptoms among workers in the cement industry: a follow up study

    Directory of Open Access Journals (Sweden)

    Zeleke Zeyede K

    2011-11-01

    Full Text Available Abstract Background There are only a few follow-up studies of respiratory function among cement workers. The main aims of this study were to measure total dust exposure, to examine chronic respiratory symptoms and changes in lung function among cement factory workers and controls that were followed for one year. Methods The study was conducted in two cement factories in Ethiopia. Totally, 262 personal measurements of total dust among 105 randomly selected workers were performed. Samples of total dust were collected on 37-mm cellulose acetate filters placed in closed faced Millipore-cassettes. Totally 127 workers; 56 cleaners, 44 cement production workers and 27 controls were randomly selected from two factories and examined for lung function and interviewed for chronic respiratory symptoms in 2009. Of these, 91 workers; 38 cement cleaners (mean age 32 years, 33 cement production workers (36 years and 20 controls (38 years were examined with the same measurements in 2010. Results Total geometric mean dust exposure among cleaners was 432 mg/m3. The fraction of samples exceeding the Threshold Limit Value (TLV of 10 mg/m3 for the cleaners varied from 84-97% in the four departments. The levels were considerably lower among the production workers (GM = 8.2 mg/m3, but still 48% exceeded 10 mg/m3. The prevalence of all the chronic respiratory symptoms among both cleaners and production workers was significantly higher than among the controls. Forced Expiratory Volume in one second (FEV1 and FEV1/Forced Vital Capacity (FEV1/FVC were significantly reduced from 2009 to 2010 among the cleaners (p Conclusions The high prevalence of chronic respiratory symptoms and reduction in lung function is probably associated with high cement dust exposure. Preventive measures are needed to reduce the dust exposure.

  7. Case study: evaluation of continuos blending silos in the cement industry, by the aid of tracer techniques

    International Nuclear Information System (INIS)

    Besides the actual burning process in cement manufacture, particular importance is attached to raw material preparation and homogenization, not only because of the quality of the kiln fed and therefore of the produced cement, but also because of the economy of the kiln operation, which significantly depends on the uniformity of the chemical composition of the material. As a result, the blending process of the cement raw material, before burning, is a basic stage of cement technology production. In this case, the pneumatic homogenization process is studied in a silo with a great storing and processing capacity. The objective is to evaluate the parameters which influence in the continuos operation. The method allows us to determine the optimal blending parameters, through the observation of the movement and distribution of the different fractions of fine dust raw meal, labelled with La-140 as tracer. Changes in blending according to time are discussed as well as the influence of the silo design on the degree of homogenization. It was showed that the silo blending operation has a strong influence on the production of good-quality cement as well as the implications on energy saving

  8. ULTRA-LIGHTWEIGHT CEMENT

    Energy Technology Data Exchange (ETDEWEB)

    Fred Sabins

    2003-01-31

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report discusses testing that was performed for analyzing the alkali-silica reactivity of ULHS in cement slurries. DOE joined the Materials Management Service (MMS)-sponsored joint industry project ''Long-Term Integrity of Deepwater Cement under Stress/Compaction Conditions.'' Results of the project contained in two progress reports are also presented in this report.

  9. Penetration of natural gas in industrial processes for direct burning: the case of ceramics, cement and glass industries; Penetracao do gas natural em processos industriais de queima direta: caso das industrias ceramica, cimento e vidro

    Energy Technology Data Exchange (ETDEWEB)

    Berni, Mauro Donizeti; Leite, Alvaro A. Furtado [Universidade Estadual de Campinas (UNICAMP), SP (Brazil); Dorileo, Ivo Leandro [Universidade Federal do Mato Grosso (NIEPE/UFMT), Cuiaba, MT (Brazil). Nucleo Interdisciplinar de Estudos em Planejamento Energetico; Bajay, Sergio Valdir [Universidade estadual de Campinas (FEM/UNICAMP), SP (Brazil). Fac. de Engenharia Mecanica. Dept. de Energia], e-mail: bajay@fem.unicamp.com.br

    2008-07-01

    Industrial sector can use the natural gas (NG) as raw material, as fuel and in co-generation. The NG as fuel is used, predominantly, to produce heat in the Brazilian industries. That rate, both main forms of industrial use of the NG are its direct burning in kilns - when the direct contact is had with the product - and the supply of process heat through boilers, for instance. Direct burning is used in the ceramic, cement and glass industries. This work discuss the penetration opportunity of the NG in the direct burning regarding the fuel oil and other energy that it can substitute, the environmental effects and the co-generation possibilities in each one of the analyzed industrial blanches in this work. (author)

  10. Produktie van cement

    NARCIS (Netherlands)

    Smit JRK; Coenen PWHG; Matthijsen AJCM; LAE; TAUW

    1995-01-01

    This document on cement production has been published within the SPIN project. In this project information has been collected on industrial plants or industrial processes to afford support to governmental policy on emission reduction. This document contains information on the processes, emission sou

  11. Causality between energy consumption and output growth in the Indian cement industry: An application of the panel vector error correction model (VECM)

    International Nuclear Information System (INIS)

    The aim of this paper is to examine the existence and direction of the causal relationship between energy consumption and output growth in the Indian cement industry for the period 1979-80 to 2004-05. The most recently developed panel unit root, a heterogeneous panel cointegration and panel-based error correction model, is applied within a multivariate framework. The empirical results confirm a positive, long-run cointegrated relationship between output and energy consumption when heterogeneous state effects are taken into account. We also found a long-run, bi-directional relationship between energy consumption and output growth in the Indian cement industry for the study period, implying that an increase in energy consumption directly affects the growth of this sector and that growth stimulates further energy consumption. These empirical findings imply that energy consumption and output are jointly determined and affect each other. The empirical evidence also suggests the implementation of energy conservation policies oriented toward improving energy-use efficiency to avoid any negative impacts of the conservation policies on the growth of this industry.

  12. Mapping and modeling multiple benefits of energy efficiency and emission mitigation in China’s cement industry at the provincial level

    International Nuclear Information System (INIS)

    Highlights: • Provincial disparities in energy use and emissions are quantified for China’s cement industry. • We describe emission mitigation impacts on EEMs with integrated assessment model. • We quantify the multiple benefits potential in China’s cement industry on provincial level. • Energy efficiency would lead to huge reductions in air pollution in all provinces. • We discuss uncertainty in relation to distribution of energy saving and emission reduction. - Abstract: China’s cement industry is the second largest energy consumer and key emitter of CO2 and air pollutants. It accounts for 7% of total energy consumption in China and 15% of CO2, 21% of PM, 4% SO2 and 10% of NOx of total emissions, respectively. Provincial disparities in energy consumption and emissions of CO2 and air pollutants in China’s cement industry are rarely quantified. In this study, an integrated assessment model including provincial energy conservation supply curves (ECSC) (which can shows the cost-effective and technical energy saving potential per province), the Greenhouse Gas and Air Pollution Interactions and Synergies (GAINS) model (which can be used to calculate air pollutant emissions), and ArcGIS (a geographical information system (GIS) with elaborated spatial functions) is developed and used to assess the potential of energy savings in terms of emission mitigation of CO2 and air pollutants and multiple benefits of energy efficiency measures at the provincial level during the period 2011–2030. The results show significant heterogeneity across provinces in terms of potential of energy saving as well as emission mitigation of CO2 and air pollutants (i.e. PM, SO2, and NOx) in the next two decades. Seven provinces (i.e. Shandong, Sichuan, Jiangsu, Guangdong, Zhejiang, Henan, Hebei), six of which are located in the central- and east-China, account for 47% of the total energy saving potential, equivalent to 26% of baseline energy use in 2030. The energy efficiency

  13. Trends in the location of the European car industry from an analysis of trade in parts and components; Tendencias en la localizacion de la industria Europea de automocion. Un analisis a partir del comercio de partes y componentes

    Energy Technology Data Exchange (ETDEWEB)

    Blazquez Gomez, L.; Diaz Mora, C.; Gandoy Juste, R.

    2010-07-01

    The object of this paper is to study the changes in location and specialization in the European automotive industry since the mid-nineties. The analysis is based on the examination of trade flows, distinguishing between final goods and parts and components, and on the delimitation of revealed comparative advantages for those countries leading the European industry. The results show the significance of the European production networks and the increasing new Eastern member countries role in them. Besides, they allow us to establish the main participant countries competitive position in those networks. As far as the Spanish industry is concerned, two aspects must be pointed out. On the one hand, the decrease in the advantages in cars assembly although the specialization in industrial motor vehicles maintains. And on the other hand, the competitive capacity showed by some auxiliary car industries. (Author) 22 refs.

  14. 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...

  15. Development of test methods for assessing microbial influenced degradation of cement-solidified radioactive and industrial waste

    International Nuclear Information System (INIS)

    This paper reports on the development of accelerated tests for evaluating microbial influenced degradation (MID) of cement-solidified wastes. An existing U.S. Nuclear Regulatory Commission accelerated test cannot distinguish between degradation caused by biogenic acid produced under optimal conditions in a bioreactor and that caused by active biofilms formed on the waste materials. Nutrient limitations were also observed that would significantly limit the activity of any developing biofilm. Results from this work have shown that it is possible to modify this test to remove nutrient limitations and enable the effects of MID resulting from active biofilms to be examined. Aggressive MID microorganisms can form a biofilm on the surface of cement-solidified waste so that when nutrients are provided the microbes remain active. Elemental mass loss data from exposed solidified waste forms indicate the continued development and growth of microbes on the surface of samples

  16. Spatial analysis of cement production and consumption in Turkey

    OpenAIRE

    Beygo, Cem; Cakmak, Goksenin

    1998-01-01

    After 1950?s, the rapid urbanization of Turkey stimulated the production and consumption of cement and the number of cement factories increased since then. In addition, construction of highways, bridges, dams and industrialization also contribute to the consumption of cement. Construction industry became a locomotif of the economy of the country and cement industry is the most element of the construction industry. This study analyzes the growth of population and urbanization according to new ...

  17. CO2 Capture by Cement Raw Meal

    DEFF Research Database (Denmark)

    Pathi, Sharat Kumar; Lin, Weigang; Illerup, Jytte Boll; Dam-Johansen, Kim; Hjuler, Klaus

    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...... capacity (Xr). This shows 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....

  18. CEMENT SLURRIES FOR GEOTHERMAL WELLS CEMENTING

    OpenAIRE

    Nediljka Gaurina-Međimurec; Davorin Matanović; Gracijan Krklec

    1994-01-01

    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...

  19. 浅谈水泥工业用带式输送机的绿色设计%The Green Design of the Belt Conveyor for Cement Industry

    Institute of Scientific and Technical Information of China (English)

    黄兰

    2015-01-01

    带式输送机广泛应用于水泥工业的多个环节,在转运和输送粉粒状物料的过程中,易产生扬尘和洒落,造成粉尘污染。为了有效降低粉尘污染,引入绿色设计理念,介绍相关粉尘控制的绿色设计方法、技术和措施,实现带式输送机的清洁运输。%Belt conveyor is widely used in cement industry .When transferring the powdery or particulate material ,dust pollution is caused by the fugitive dust .In order to reduce dust pollution ,introducing the concept of green design ,including green design methods ,techniques and measures for dust control .

  20. 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

  1. Physicochemical study of bagasse and bagasse ash from the sugar industries of NWFP, pakistan and its recycling in cement manufacturing

    International Nuclear Information System (INIS)

    Bagasse and bagasse ash, obtained from the local sugar mills of North West Frontier Province (NWFP), Pakistan, were analyzed for both physical and chemical parameters. Among the physical parameters, the moisture, ash contents, volatile matter, loss on ignition, and calorific value have been determined while the chemical constituents such as SiO/sub 2/, AI/sub 2/O/sub 3/ Fe/sub 2/O/sub 3/ CaO, MgO, Na/sub 2/O, K/sub 2/O, carbon and sulfur were also determined in both baggase and baggase ash. The physicochemical characterization of baggase ash suggests that it can be used as a part of the cement admixture, which could be cost effective and environmentally sustainable. (author)

  2. Research on the Differences of Evaluative Bases About Air Pollutants Emission From Cement Industry in Yunnan Province

    Science.gov (United States)

    Yu, Y.; Jiang, Y. X.; Wu, J. L.; Yan, L.; Wang, K. D.; Du, Y.

    Environment impact assessment (EIA) and the check and accepts of completed project (CACP) are two evaluative bases usually used to estimate pollutant emission. In order to find out the differences between them, this study collected the EIA approval documents and CACP reports from 50 key cement plants in Yunnan province, by statistical methods to analyze the data. Results as follows: Emission factors (EF) from EIA are much greater than CACP, data distribution difference: SO2 is significant, dust and NOx are insignificant. The EF of EIA and CACP has no relationship with linear regression analysis. Reasons: Original data used in EIA are not fit the actual pollution status completely, CACP operational difficulties and regional variation still exist. This study first found out the statistical differences between EIA and CACP in Yunnan. For increasing the accuracy of EIA, we should reference the local actual emission status in the process of EIA.

  3. The cement recycling of the earthquake disaster debris by Hachinohe Cement Co., Ltd

    International Nuclear Information System (INIS)

    A tremendous quantity of earthquake disaster debris and tsunami sediment was resulted by the Great East Japan Earthquake on March 11, 2011. Hachinohe Cement Co., Ltd., a Sumitomo Osaka Cement subsidiary, was the first cement industry company to receive and process such waste materials outside of their usual prefecture area, while the company is performing their treatment and recycling services locally in Hachinohe City and Aomori Prefecture. This report provides an explanation about the recycling mechanism of waste materials and by-products in cement manufacturing process, and introduces an example of actual achievements for the disaster debris treatment by utilizing the cement recycling technologies at the Hachinohe Cement Plant. (author)

  4. The effects of BaSO4 loading on OPC cementing system for encapsulation of BaSO4 scale from oil and gas industry

    International Nuclear Information System (INIS)

    Highlights: • Fine BaSO4 powder can promote the formation of CaCO3 in the wasteform. • w/c = 0.53 is better than w/s = 0.53 to maintain the low porosity and low carbonation. • Water has little impact on the formation of CaCO3 when coarse BaSO4 was introduced. • It is possible to load 60 wt% of BaSO4 with a sufficient integrity of wasteform. -- Abstract: The BaSO4 scales obtained from piping decontamination from oil and gas industries are most often classified as low level radioactive waste. These wastes could be immobilised by stable cement matrix to provide higher safety of handling, transportation, storage and disposal. However, the information available for the effects of the basic formulation such as waste loading on the fundamental properties is still limited. The present study investigated the effect of BaSO4 loading and water content on the properties of OPC–BaSO4 systems containing fine BaSO4 powder and coarse granules. The BaSO4 with different particle size had a marked effect on the compressive strength due to their different effects on hydration products formed. Introduction of fine BaSO4 powder resulted in an increased formation of CaCO3 in the system, which significantly contributed to the compressive strength of the products. Amount of water was important to control the CaCO3 formation, and water to cement ratio of 0.53 was found to be a good level to maintain a low porosity of the products both for fine BaSO4 powder and coarse BaSO4 granule. BaSO4 loading of up to 60 wt% has been achieved satisfying the minimum compressive strength of 5 MPa required for the radioactive wasteforms

  5. Health hazards of cement dust

    International Nuclear Information System (INIS)

    ven in the 21st century, millions of people are working daily in a dusty environment. They are exposed to different types of health hazards such as fume, gases and dust, which are risk factors in developing occupational disease. Cement industry is involved in the development of structure of this advanced and modern world but generates dust during its production. Cement dust causes lung function impairment, chronic obstructive lung disease, restrictive lung disease, pneumoconiosis and carcinoma of the lungs, stomach and colon. Other studies have shown that cement dust may enter into the systemic circulation and thereby reach the essentially all the organs of body and affects the different tissues including heart, liver, spleen, bone, muscles and hairs and ultimately affecting their micro-structure and physiological performance. Most of the studies have been previously attempted to evaluate the effects of cement dust exposure on the basis of spirometry or radiology, or both. However, collective effort describing the general effects of cement dust on different organ and systems in humans or animals, or both has not been published. Therefore, the aim of this review is to gather the potential toxic effects of cement dust and to minimize the health risks in cement mill workers by providing them with information regarding the hazards of cement dust. (author)

  6. 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.

  7. 水泥工业CO2减排及利用技术进展%Technical Progress of Emission-reduction and Utilization of Carbon Dioxide in Cement Industry

    Institute of Scientific and Technical Information of China (English)

    马忠诚; 汪澜

    2011-01-01

    Emission-reduction exists potentially in cement industry, which is the key industry for carbon dioxide emission. Carbonate decomposition, fuel combustion and electric power consumption, etc. Which discharge carbon dioxide in cement industry, are introduced. A series of methods for decreasing carbon dioxide emission in cement industry, such as improving energy utilization, using alternative raw materials and fuels, developing new low carbone-mission binding materials, etc. Are expounded. Finally, several technologies for recycling of carbon dioxide, such as separation, capture, storage, fixation, etc. Are suggested.%水泥工业是CO2排放的重点行业,减排潜力巨大.全面介绍了水泥生产中碳酸盐分解、燃料燃烧和电力消耗等方面CO2的排放情况;详细阐述了水泥生产中通过提高能源利用率、使用替代原燃料、开发新型低碳排放的胶凝材料等措施实现CO2减排的方法,提出了对水泥工业CO2排放实施的分离、捕集、封存、固定等回收利用技术.

  8. Industry

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein, Lenny; Roy, Joyashree; Delhotal, K. Casey; Harnisch, Jochen; Matsuhashi, Ryuji; Price, Lynn; Tanaka, Kanako; Worrell, Ernst; Yamba, Francis; Fengqi, Zhou; de la Rue du Can, Stephane; Gielen, Dolf; Joosen, Suzanne; Konar, Manaswita; Matysek, Anna; Miner, Reid; Okazaki, Teruo; Sanders, Johan; Sheinbaum Parado, Claudia

    2007-12-01

    This chapter addresses past, ongoing, and short (to 2010) and medium-term (to 2030) future actions that can be taken to mitigate GHG emissions from the manufacturing and process industries. Globally, and in most countries, CO{sub 2} accounts for more than 90% of CO{sub 2}-eq GHG emissions from the industrial sector (Price et al., 2006; US EPA, 2006b). These CO{sub 2} emissions arise from three sources: (1) the use of fossil fuels for energy, either directly by industry for heat and power generation or indirectly in the generation of purchased electricity and steam; (2) non-energy uses of fossil fuels in chemical processing and metal smelting; and (3) non-fossil fuel sources, for example cement and lime manufacture. Industrial processes also emit other GHGs, e.g.: (1) Nitrous oxide (N{sub 2}O) is emitted as a byproduct of adipic acid, nitric acid and caprolactam production; (2) HFC-23 is emitted as a byproduct of HCFC-22 production, a refrigerant, and also used in fluoroplastics manufacture; (3) Perfluorocarbons (PFCs) are emitted as byproducts of aluminium smelting and in semiconductor manufacture; (4) Sulphur hexafluoride (SF{sub 6}) is emitted in the manufacture, use and, decommissioning of gas insulated electrical switchgear, during the production of flat screen panels and semiconductors, from magnesium die casting and other industrial applications; (5) Methane (CH{sub 4}) is emitted as a byproduct of some chemical processes; and (6) CH{sub 4} and N{sub 2}O can be emitted by food industry waste streams. Many GHG emission mitigation options have been developed for the industrial sector. They fall into three categories: operating procedures, sector-wide technologies and process-specific technologies. A sampling of these options is discussed in Sections 7.2-7.4. The short- and medium-term potential for and cost of all classes of options are discussed in Section 7.5, barriers to the application of these options are addressed in Section 7.6 and the implication of

  9. Cement replacement materials. Properties, durability, sustainability

    Energy Technology Data Exchange (ETDEWEB)

    Ramezanianpour, Ali Akbar [Amirkabir Univ. of Technology, Tehran (Iran, Islamic Republic of). Concrete Technology Center

    2014-04-01

    The aim of this book is to present the latest findings in the properties and application of Supplementary Cementing Materials and blended cements currently used in the world in concrete. Sustainability is an important issue all over the world. Carbon dioxide emission has been a serious problem in the world due to the greenhouse effect. Today many countries agreed to reduce the emission of CO2. Many phases of cement and concrete technology can affect sustainability. Cement and concrete industry is responsible for the production of 7% carbon dioxide of the total world CO2 emission. The use of supplementary cementing materials (SCM), design of concrete mixtures with optimum content of cement and enhancement of concrete durability are the main issues towards sustainability in concrete industry.

  10. Characterization of cement composites with mineral additives

    OpenAIRE

    Korat, Lidija

    2015-01-01

    Doctoral dissertation is aimed at characterizing cement composites with mineral additives representing the industrial waste material (fly ash, granulated blast furnace slag and biomass fly ash). Their usage can replace high cement shares in individual cases and is, however, favourable due to the production costs reduction and environment burden decrease, including the decreased emission of greenhouse gases as well as lower energy use. Cement composites (in fresh or hardened state)...

  11. Bottom-up Representation of Industrial Energy Efficiency Technologies in Integrated Assessment Models for the Cement Sector

    Energy Technology Data Exchange (ETDEWEB)

    Sathaye, J.; Xu, T.; Galitsky, C.

    2010-08-15

    Adoption of efficient end-use technologies is one of the key measures for reducing greenhouse gas (GHG) emissions. How to effectively analyze and manage the costs associated with GHG reductions becomes extremely important for the industry and policy makers around the world. Energy-climate (EC) models are often used for analyzing the costs of reducing GHG emissions for various emission-reduction measures, because an accurate estimation of these costs is critical for identifying and choosing optimal emission reduction measures, and for developing related policy options to accelerate market adoption and technology implementation. However, accuracies of assessing of GHG-emission reduction costs by taking into account the adoption of energy efficiency technologies will depend on how well these end-use technologies are represented in integrated assessment models (IAM) and other energy-climate models.

  12. 中国水泥工业CO2产生机理及减排途径研究%CO2 emissions from the Chinese cement industry and methods to reduce them

    Institute of Scientific and Technical Information of China (English)

    李新; 石建屏; 吕淑珍; 王海滨

    2011-01-01

    根据水泥生产的基本原理和工艺特点,推导出煤燃烧和石灰质原料煅烧时CO2排放因子分别为2.38 t·t-1和0.527 t·t-1;采用水泥工业CO2排放数学模型计算2001-2008年中国水泥工业CO2排放量,并分析了不同的生产技术水平和产品品种结构对CO2,排放量的影响.结果表明:中国水泥工业CO2排放量与单位产品的能源和资源消耗量呈线性关系,在CO2排放量构成中,燃料燃烧和加工过程CO2排放量分别占46%和50%,间接电力消耗CO2排放量仅占4%;采用新型干法生产技术比传统方法减少CO2排放量34%,生产掺加混合材料的水泥比硅酸盐水泥减少CO2排放量35%.2008年中国水泥产量比2007年增长2%,而CO2排放量仅增长0.23%,说明水泥工业实施节能降耗、资源循环利用等技术措施对于减少CO2排放具有显著效果.%According to the principles and characteristics of cement production, the emission factors of car1oon dioxide were calculated to be 2.38 t·t -1 for burning coal and and 0.527 t·t-1 for burning lime materials. A mathematical model of CO2 emission in the cement industry was used to deduce the CO2 emissions load of the Chinese cement industry from 2001 to 2008. The results indicated that there is a linear relationship between the Chinese industrial emission of CO2 and the energy and resource consumption per unit product. CO2 emitted in the fuel burning and cement producing process were respectively responsible for 46% and 50% of total CO2 emissions by the cement industry. Indirect power loss occupied only 4% of total CO2 emissions.When the new suspension preheater(NSP) cement technique was used, CO2 emission decreased by 34% compared with that produced by the traditional technique. The CO2 emission of cement and admixture production decreased by 35% compared with Portland cement production. Compared with 2007,total Chinese cement outputs increased 2% in 2008, but there was only a 0.23% increase in CO

  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 for...... the most significant alternative fuel energy contributors in the German cement industry. Solid alternative fuels are typically high in volatile content and they may differ significantly in physical and chemical properties compared to traditional solid fossil fuels. From the process point of view......, considering a modern kiln system for cement production, the use of alternative fuels mainly influences 1) kiln process stability (may accelerate build up of blockages preventing gas and/or solids flow), 2) cement clinker quality, 3) emissions, and 4) decreased production capacity. Kiln process stability in...

  14. The Effects of the Asian Crisis To Turkish Manufacturing Industry : The Case of Textile, Food and Cement Industries = Asya Krizinin Türk İmalat Sanayisine Etkileri: Tekstil, Gıda ve Çimento Sanayileri Örneği

    Directory of Open Access Journals (Sweden)

    Abdülmecit KARATAŞ

    2001-06-01

    Full Text Available This paper hypothesizes that Asian crisis has severely affected the financial dimensions of the Turkish industries. The analysis of the financial data for 70 companies from textile, food and cement industries provides evidence to partially support this hypothesis. By principal components analysis we identified five statistical factors that is meaningful and economically significant to represent main financial dimensions contained in twenty-one financial variables of the sample firms. The discriminant analyses based on the identification of the discrimination between financial dimensions of the sample firms for pre- and post-crisis years identified that profitability margins of the export-oriented Turkish textile industry significantly decreased in post-crisis years. No statistically significant changes in financial dimensions are detected for food and cement industries in post-crisis years.

  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....... 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...

  16. 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.

  17. Consumption reduction and emission reductionof cement production made by steel industrial solid waste%钢铁工业固废应用于水泥生产的降耗与减排

    Institute of Scientific and Technical Information of China (English)

    邓琪; 陈吉宁

    2012-01-01

    运用物质流分析法定量比较原生水泥与再生水泥生产过程中的物能代谢和环境负荷,并采用生命周期分析进行环境影响评价.结果表明:生产1t原生水泥需要的直接物质投入是1.637 t;消耗原煤0.086t/标准煤,消耗电力0.067t/标准煤.利用钢铁工业固废生产功能单位再生水泥,可减少资源投入0.16 t;减少能源消耗0.036 t;环境排放SO2减排0.0002 t;粉尘减排0.001 t;烟尘减排0.000 12 t;NOx减排0.000 34 t;CO2减排0.231 t.水泥生产潜在的各类环境影响中以废气排放引起的温室效应最大;其次依次是酸化效应和不可再生资源消耗;光化学烟雾和人体健康损害在水泥生产过程中的影响都相对较小.与原生水泥相比,再生水泥各环境负荷均呈下降趋势,两者总体环境负荷差值为6.93E-15.研究结果充分说明钢铁工业固废资源化可以明显的降低水泥生产的总体环境负荷,是促进水泥行业循环经济发展的有效手段.%Material-energy metabolism and environment load in the production of primary cement and regeneration cement were compared quantitatively using Material Flow Analysis (MFA) and were evaluated of the environmental impact using Life Cycle Assessment (LCA). It was shown from the results: direct material input to produce one ton of primary cement was 1.637 tons, raw coal consumption was 0.086t/standard coal, and electricity consumption was 0.067 t/standard coal. Resource input to produce one ton of regeneration cement using steel industry solid waste could be reduced by 0.16 t, energy consumption by 0.036 t, SO2 emission by 0.000 2 t, dust emission by 0.001 t, smoke emission by 0.000 12 t, Nox emission by 0.000 34 t, CO2 emission by 0.231 t. Among various environment impact in the production of cement, waste gas emission contributed the most to Global Wanning Potential (GWP), Acidification Potential (AP), the second, Abiotic Depletion Potential (ADP), the third

  18. El Ahorro Privado en Venezuela: Tendencias y Determinantes

    OpenAIRE

    Matías Riutort; Rafael Muñoz; Juan Carlos Guevara; Luis Zambrano Sequín

    1998-01-01

    La característica notable del comportamiento de la tasa de ahorro privado en Venezuela es su tendencia secular a reducirse desde los elevados niveles experimentados durante los años setenta a los muy reducidos de los noventa. Adicionalmente a esta tendencia al deterioro, habría que añadir su alta volatilidad. Las razones que explican este resultado no sólo están referidas a los sucesivos shocks, externos e internos, que han afectado a Venezuela, sino también a la forma peculiar como se ha ges...

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

    Institute of Scientific and Technical Information of China (English)

    LU Jiang; Chirdchanin MODMOLTIN; Katsutada ONITSUKA

    2004-01-01

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

  20. Physico-Chemical and Radioactive Characterization of Co-Products from the Titanium Dioxide NORM Industry for their Use in Cement Manufacturing

    International Nuclear Information System (INIS)

    This paper presents the results of a study to characterize the raw materials (ilmenite and slag), residue (red gypsum) and co-products (ferrous sulphate monohydrate and heptahydrate) associated with titanium dioxide production, in particular their elemental composition (major, minor and trace elements), mineralogy and radioactive content, with the objective of applying this knowledge to facilitate the use of some of these materials in applications such as construction and civil engineering. Obviously, the environmental and health impact of the co-products should comply with existing regulations. In particular, the main properties of cement produced with different proportions of red gypsum and the improvements obtained in relation to ordinary Portland cement have been studied. It is demonstrated that the levels of pollutants in the red gypsum cement remain within safety limits. (author)

  1. Status quo of energy recovery from waste in special industrial facilities and evaluation of the environmental impacts of using refuse derived fuel (RDF) in cement kilns in Germany; Untersuchung der Umweltauswirkungen des Einsatzes von Abfaellen ausserhalb thermischer Abfallbehandlungsanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Alwast, H.; Marton, C.; Koepp, M.

    2001-10-01

    Within the study presented here the use of energy recovery from waste was analysed for several industrial facilities, focussing on cement plants, kilns in the lime and gypsum industry, steel works and plants for the production of non ferrous metals. 44 German cement plants dispose of an own clinker production. Presently 31 plants have a permit for recovering energy from waste. The total permitted capacity for energy recovery in German cement kilns amounts to nearly 2,6 Mio. t/a. Mainly waste oil, old tyres, fuel derived from processed production-specific and municipal waste, plastics, scrap wood and waste paper are co-incinerated. In 1998/99 a total amount of roughly 945.000 t refuse was processed in 30 units of the studied facilities. In five furnaces at three steel works waste can be used for energy or material recovery. The approved total capacity of high calorific waste for energy recovery comes to nearly 350,000 t/a. Especially industrial plastics and packaging waste from DSD, plastics processed in scrap mills and shreddered waste and granulated paint sludge are used. In 1998 the facilities processed only old plastic, representing a total amount of nearly 109.000 t. At present seven facilities in the non ferrous metal industry have a permit for energy recovery from waste. The maximum capacity amounts on national level to nearly 140.000 t/a. Especially waste oil, packaging waste, plastics and scrap wood can be processed. The analysis of respective applications of the 17th BImSchV shows an inconsistency within the amending permitting procedures. For the time to come a conformity between the respective regional permitting authorities would be recommendable. Moreover, the effects on air emission caused by using waste for energy recovery were analysed for cement kilns with own clinker production. Due to the amendment of the 17th BImSchV more stringent requirements regarding waste composition must be established. This is especially valid for the highly volatile

  2. The effects of carbon prices and anti-leakage policies on selected industrial sectors in Spain – Cement, steel and oil refining

    International Nuclear Information System (INIS)

    This paper assesses the impacts on the cement, steel and oil refining sectors in Spain of the carbon prices derived from the European Emissions Trading Scheme (EU ETS), and the potential effect on these sectors of the European Union anti-leakage policy measures. The assessment is carried out by means of three engineering models developed for this purpose. Our results show a high exposure to leakage of cement in coastal regions; a smaller risk in the steel sector, and non-negligible risk of leakage for the oil refining sector when carbon allowance prices reach high levels. We also find that the risk of leakage could be better handled with other anti-leakage policies than those currently in place in the EU. - Highlights: • We simulate the impact of carbon prices on the risk of leakage in the cement, steel and oil refining sectors. • We also assess the effectiveness of different anti-leakage policies in Europe. • Cement production in coastal areas is highly exposed. • The risk of leakage for steel and oil refining is smaller. • Anti-leakage policies should be modified to be efficient

  3. INFLUENCE OF WINE ACID ON RHEOLOGICAL PROPERTIES OF WELL BORE CEMENT SLURRIES AND HARDENED CEMENT PROPERTIES

    Directory of Open Access Journals (Sweden)

    Nediljka Gaurina-Međimurec

    1989-12-01

    Full Text Available Adaptation of commercial types of domestic cements for use in cementing the deep wells is a process by which Yugoslav oil industry tends to solve problems of completion of those wells independently. In order to design a domestic, cheep and effective retarder, tests of applicability of wine acid on cement slurries have been carried out. Besides examining the necessary wine acid content to achieve desirable Theological properties, the influence of this additive on properties of hardened cement samples has been tested too (the paper is published in Croatian.

  4. Three big Cs: climate, cement and China

    Energy Technology Data Exchange (ETDEWEB)

    Nordqvist, Joakim [Lund Univ., Lund (Sweden); Boyd, Christopher [Lafarge (France); Klee, Howard [World Business Council for Sustainable Development (Switzerland)

    2003-09-30

    Cement is a low-cost construction material whose manufacture generates significant carbon dioxide emissions. As these emissions enter a carbon-constrained world, they may ultimately have a significant impact on the industry's financial performance. Consequently, the cement industry is developing a response to climate change management and the connected political process. Ten of the world's leading cement-producing corporations, representing more than one-third of global cement production, published a joint Agenda for Action in 2002 to address sustainability issues for the industry, including climate change. Other issues identified are emissions reduction, use of fuels and raw materials, employee health and safety, local impacts on land and communities, and internal business processes. Examining the rationale for, and the effects of, proactive climate initiatives in the cement sector, this paper elaborates on the conditions for the spread of cement-related climate action to China, where more than one-third of global cement production occurs, 80% of which involves inefficient kilns using outdated, highly polluting technology. (Author)

  5. Analysis of Waste Gas Volume and Pollutants Reduction Potential for Cement Industry in China%我国水泥工业废气量减排与污染物减排潜力分析

    Institute of Scientific and Technical Information of China (English)

    王红梅; 刘宇; 王凡; 都基峻; 张凡; 石应杰

    2015-01-01

    水泥工业是颗粒物等大气污染物排放量较大的行业,因排放标准中颗粒物等污染物浓度限值已非常严格,依靠加严标准减排污染物的空间已经越来越小,标准减排难以使水泥工业实现更高的减排目标。水泥生产多个工序会排放废气,在排放标准限值不变的条件下,各类废气的排放总量决定了颗粒物等污染物的排放总量。通过实例分析得出利用窑头余风再循环、减少窑头喂煤一次风比例和分解炉喂煤风机的风量可实现高温废气量的减排,利用窑头窑尾低温废热进行烘干物料可实现低温烘干废气量的减排,将常温废气作为水泥窑窑头和分解炉煤粉的助燃空气可实现常温废气量的减排,进一步分析了通过废气量减排可实现颗粒物等污染物的减排量。%Cement industry yields a large air pollution emission including particulate matters.As the particulate concentration limits in the industrial emission standard has been very strict, it leaves smaller and smaller space to further reduce the pollutant emission by setting stricter standard limits.Therefore, the emission reduction by standard has been difficult to make cement industry to achieve a higher reduction target.There are several processes in cement production that emit waste gases.Under the same emission standard limits, the total emissions of various pollutants will be determined by the total waste gas volumes of various kinds.Through case studies, it was shown that the kiln end afterwinds could be recycled to reduce the primary air ratio in kiln end coal feeding and the coal-feeding fan air volume in calcining combustors, so as to realize reduction of high-temperature waste gas volume. The cement kiln end low-temperature waste heat could be used to dry materials and thus realize reduction of waste gas volume in low-temperature drying.The room-temperature exhaust gas could be used as pulverized coal combustion air

  6. Low pH Cements

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-05-15

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

  7. Low pH Cements

    International Nuclear Information System (INIS)

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

  8. Cross-shift study of acute respiratory effects in cement production workers.

    OpenAIRE

    Omid Aminian; Maryam Aslani; Khosro Sadeghniiat Haghighi

    2014-01-01

    Cement dust exposure is associated with increased respiratory impairment. As the major occupational hazard in the cement production industry is cement particles, our aim was to more thoroughly examine the acute effects of occupational exposure to cement dust on the respiratory system. A cross-shift study was conducted in a cement factory in Iran. 100 high exposed workers from production and packing sections and 100 low exposed from office workers were included. Environmental total dust was me...

  9. First industrial scale pre combustion chamber at the Wildegg cement plant; Premiere chambre de precombustion industrielle pour pneux usages a la cimenterie de Wildegg

    Energy Technology Data Exchange (ETDEWEB)

    Bertschinger, P. [Jura-Cement-Fabriken, Wildegg (Switzerland)

    2001-10-01

    This article presents the main components of the Wildegg cement plant of Jura-Cement-Fabriken company (Switzerland): a roller mill for the production of raw meal, a four-stage cyclone preheater, a staggered combustion calciner, a rotary kiln, and a reciprocating grate cooler. The article stresses on the design and test-phase of the pre-calciner and of the pre-combustion chamber for the use of used tyres as fuel substitutes with the goals of reaching up to 60-80% of tyres in the total pre-calciner fuel and without residues. The use of tyres has had no negative effect on the pollutant emissions with unchanged CO and VOC emissions and NO{sub x} emissions actually reduced by up to 40%. (J.S.)

  10. Globally Oriented Chinese Plastics Industry

    Institute of Scientific and Technical Information of China (English)

    Liao Zhengpin

    2004-01-01

    @@ Through continued endeavor and persistent opening to the whole world the Chinese plastics industry has been developed into a comprehensive industrial system that forms the basic material industries side by side with the steel, cement and the timber industry.

  11. ADVANCED CEMENTS FOR GEOTHERMAL WELLS

    Energy Technology Data Exchange (ETDEWEB)

    SUGAMA,T.

    2007-01-01

    Using the conventional well cements consisting of the calcium silicate hydrates (CaO-SiO{sub 2}-H{sub 2}O system) and calcium aluminum silicate hydrates (CaO-Al{sub 2}O{sub 3}-SiO{sub 2}-H{sub 2}O system) for the integrity of geothermal wells, the serious concern confronting the cementing industries was their poor performance in mechanically supporting the metallic well casing pipes and in mitigating the pipe's corrosion in very harsh geothermal reservoirs. These difficulties are particularly acute in two geological regions: One is the deep hot downhole area ({approx} 1700 m depth at temperatures of {approx} 320 C) that contains hyper saline water with high concentrations of CO{sub 2} (> 40,000 ppm) in conjunction with {approx} 100 ppm H{sub 2}S at a mild acid of pH {approx} 5.0; the other is the upper well region between the well's surface and {approx} 1000 m depth at temperatures up to 200 C. The specific environment of the latter region is characterized by highly concentrated H{sub 2}SO{sub 4} (pH < 1.5) brine containing at least 5000 ppm CO{sub 2}. When these conventional cements are emplaced in these harsh environments, their major shortcoming is their susceptibility to reactions with hot CO{sub 2} and H{sub 2}SO4, thereby causing their deterioration brought about by CO{sub 2}-catalyzed carbonation and acid-initiated erosion. Such degradation not only reduced rapidly the strength of cements, lowering the mechanical support of casing pipes, but also increased the extent of permeability of the brine through the cement layer, promoting the rate of the pipe's corrosion. Severely carbonated and acid eroded cements often impaired the integrity of a well in less than one year; in the worst cases, casings have collapsed within three months, leading to the need for costly and time-consuming repairs or redrilling operations. These were the reasons why the geothermal well drilling and cementing industries were concerned about using conventional well

  12. The suitability of a supersulfated cement for nuclear waste immobilisation

    Science.gov (United States)

    Collier, N. C.; Milestone, N. B.; Gordon, L. E.; Ko, S.-C.

    2014-09-01

    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.

  13. International Best Practices for Pre-Processing and Co-Processing Municipal Solid Waste and Sewage Sludge in the Cement Industry

    Energy Technology Data Exchange (ETDEWEB)

    Hasanbeigi, Ali [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lu, Hongyou [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Williams, Christopher [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Price, Lynn [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-07-01

    The purpose of this report is to describe international best practices for pre-processing and coprocessing of MSW and sewage sludge in cement plants, for the benefit of countries that wish to develop co-processing capacity. The report is divided into three main sections. Section 2 describes the fundamentals of co-processing, Section 3 describes exemplary international regulatory and institutional frameworks for co-processing, and Section 4 describes international best practices related to the technological aspects of co-processing.

  14. Nuevas tendencias en el proyecto de buques cableros

    OpenAIRE

    García Rupérez, Fernando

    2015-01-01

    Esta tesis tiene como objetivo actualizar los criterios de proyecto de los buques cableros, analizando las nuevas tendencias en el uso de este tipo de barcos. Se estudian las operaciones realizadas para la instalación y reparación de los cables submarinos. Del estudio de estas técnicas se extraen unos requisitos para el proyecto. Se comprueba cómo han evolucionado a lo largo de la historia las características de los buques cableros. Comparando esta evolución con las características necesarias...

  15. Influence of relationship water/cement upon the processing of cements with pozzolana in standard mortar

    Directory of Open Access Journals (Sweden)

    Gener Rizo, M.

    2002-03-01

    Full Text Available The processing of standard mortar is completed following different methods in accordance with the country, but they exist two fundamental tendecies, the ISO and the ASTM. The cuban norm for mechanic-physic tests is based in ISO, and so they use a constant relationship water/cement in the processing of standard mortar a great problem concerning the cement users when they tested those mixed with puzzolanes, because they don't take care of the bigger water needs of those materials. In this work we present an study of the behaviour of Pozzolanic Portland cements (PP-250 elaborates with a fix and changeable relationship water/cement, obtained starting from the fluidity of the pure Portland cement. (P-350 The results obtained shows that the mechanical resistance decreased in cement mortars PP-250 realised with changeable relationship water/cement. So we recommend the adoption of an optional procedure to elaborate a quality mortar with pozzolana cements.

    La elaboración del mortero normalizado se realiza internacionalmente por diferentes métodos, pero existen dos tendencias fundamentales, la enunciada por ISO y por ASTM. La norma cubana de ensayos físico-mecánicos de cemento se basa en la norma ISO, por lo que para la elaboración del mortero normalizado se utiliza una relación agua/cemento constante. Esto ha provocado discrepancias con los usuarios del cemento, especialmente cuando se ensayan los cementos que contienen puzolanas, ya que se plantea que no se tiene en cuenta la mayor demanda de agua de estos materiales. En el presente trabajo se presenta un estudio del comportamiento de cementos Portland Puzolánicos (PP-250 elaborados con una relación agua/ cemento fija y variable, lograda a partir de la fluidez de la pasta de cemento Portland puro (P-350. Los resultados obtenidos indican que se producen disminuciones en la resistencia mecánica en los morteros de cemento PP-250 elaborados con agua/ cemento variable y recomienda la

  16. 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.

  17. Colorectal cancer and non-malignant respiratory disease in asbestos cement and cement workers

    International Nuclear Information System (INIS)

    Radiologically visible parenchymal changes (small opacities >= 1/0;ILO 1980 classification) were present in 20% of a sample of workers (N=174), employed for 20 years (median) in an asbestos cement plant. Exposure-response relationships were found, after controlling for age and smoking habits. In a sample of asbestos cement workers with symptoms and signs suggestive of pulmonary disease (N=33), increased lung density measured by x-ray computed tomography, and reduced static lung volumes and lung compliance was found. In a cohort of asbestos cement workers (N=1.929) with an estimated median exposure of 1.2 fibres/ml, the mortality from non-malignant respiratory disease was increased in comparison to a regional reference cohort (N=1.233). A two-to three-fold increase of non-malignant respiratory mortality was noted among workers employed for more than a decade in the asbestos cement plant, compared to cement workers (N=1.526), who in their turn did not experience and increased risk compared to the general population. In the cohorts of asbestos cement and cement workers, there was a tow-to three-fold increased incidence of cancer in the right part of the colon, compared to the general population as well as to external reference cohorts of other industrial workers (N=3.965) and fishermen (N=8.092). A causal relation with the exposure to mineral dust and fibres was supported by the findings of higher risk estimated in subgroups with high cumulated asbestos doses or longer duration of cement work. The incidence of cancer in the left part of the colon was not increased. Morbidity data, but not mortality data, disclosed the subsite-specific risk pattern. Both asbestos cement workers and cement workers has an increased incidence of rectal cancer, compared with the general population, and with the fishermen. The risk was, however, of the same magnitude among the other industrial workers. 181 refs

  18. ULTRA-LIGHTWEIGHT CEMENT

    International Nuclear Information System (INIS)

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). Work reported herein addresses Task 1: Assess Ultra-Lightweight Cementing Issues, Task 2: Review Russian Ultra-Lightweight Cement Literature, Task 3: Test Ultra-Lightweight Cements, and Task 8: Develop Field ULHS Cement Blending and Mixing Techniques. Results reported this quarter include: preliminary findings from a literature review focusing on problems associated with ultra-lightweight cements; summary of pertinent information from Russian ultra-lightweight cement literature review; laboratory tests comparing ULHS slurries to foamed slurries and sodium silicate slurries for two different applications; and initial laboratory studies with ULHS in preparation for a field job

  19. Cement and concrete options paper

    International Nuclear Information System (INIS)

    Greenhouse gas emissions associated with the production of concrete are projected to increase from 10.5 million tonnes in 1990 to almost 14 million tonnes in 2010. Over half of this amount will be non-energy related emissions of carbon dioxide resulting from the conversion of limestone to lime. According to this report by industry experts, the industry has an excellent record of improving energy efficiency and there are few easy gains remaining. Nevertheless, improvements in energy efficiency and fuel use, increased use of concrete where it can be shown to result in net reduction of GHG emissions, and partial replacement of cement by supplementary cementitious materials that involve no additional generation of GHGs, could yield an approximate reduction in carbon dioxide emissions of nearly seven million tons in 2010. The industry proposes three measures to realise these benefits: (1) encouraging replacement of fossil fuels by otherwise waste material, (2) encouraging increased use of concrete in constructing houses and roads, and (3) encouraging increased use of supplementary cementing materials. The industry is opposed to carbon or energy taxes that increase the cost of doing business, on the grounds that such taxes would adversely affect the industry's competitive position internationally. tabs

  20. Utilization from Cement Kiln Dust in Removal of Acid Dyes

    OpenAIRE

    Mohamed E.S.I. Saraya; Mahmoud E.S. Aboul-Fetouh

    2012-01-01

    Problem statement: The growth of industries and day to day changes in human activities has resulted in an increase in the volume and complexity of wastewater to the environment. Textile industry is one of the most water consumers industries of Egypt, thus discharges large amounts of wastewater effluents during processing, especially, in the coloring and washing steps. Cement kiln dust is a solid waste in cement manufacturing. Approximately 2.5-3.0 (6-9%) million tons of cement kiln dust is pr...

  1. Soft X-ray Microscopy of Green Cements

    Science.gov (United States)

    Monteiro, P. J. M.; Mancio, M.; Kirchheim, A. P.; Chae, R.; Ha, J.; Fischer, P.; Tyliszczak, T.

    2011-09-01

    The present status of the cement and concrete industry is not sustainable. The production of Portland cement is responsible for 7% of the CO2 emissions in the world and existing reinforced concrete infrastructure is deteriorating at a fast pace. The change in the existing technology requires new developments in our understanding of the nanostructure of hydration products and the complex deterioration reactions. We have been developing an elaborate research program to advance the existing cement and concrete science by characterizing its nanostructure by synchrotron radiation. A new generation of green cements is being studied using high-resolution soft x-ray microscopy at the nano-level.

  2. Soft X-ray Microscopy of Green Cements

    International Nuclear Information System (INIS)

    The present status of the cement and concrete industry is not sustainable. The production of Portland cement is responsible for 7% of the CO2 emissions in the world and existing reinforced concrete infrastructure is deteriorating at a fast pace. The change in the existing technology requires new developments in our understanding of the nanostructure of hydration products and the complex deterioration reactions. We have been developing an elaborate research program to advance the existing cement and concrete science by characterizing its nanostructure by synchrotron radiation. A new generation of green cements is being studied using high-resolution soft x-ray microscopy at the nano-level.

  3. ULTRA-LIGHTWEIGHT CEMENT

    International Nuclear Information System (INIS)

    The objective of this project is to develop an improved ultra-lightweigh cement using ultralight hollow glass spheres (ULHS). Work reported herein addresses Task 1: Assess Ultra-Lightweight Cementing Problems, Task 2: Review Russian Ultra-Lightweight Cement Literature, and Task 3: Test Ultra-Lightweight Cements. Results reported this quarter include a review and summary surface pipe and intermediate casing cementing conditions historically encountered in the US and establishment of average design conditions for ULHS cements. Russian literature concerning development and use of ultra-lightweight cements employing either nitrogen or ULHS was reviewed, and a summary is presented. Quality control testing of materials used to formulate ULHS cements in the laboratory was conducted to establish baseline material performance standards. A testing protocol was developed employing standard procedures as well as procedures tailored to evaluate ULHS. This protocol is presented and discussed. finally, results of initial testing of ULHS cements is presented along with analysis to establish cement performance design criteria to be used during the remainder of the project

  4. Reuse of a residue from petrochemical industry with portland cement Reutilización de un residuo de la industria petroquímica como adición al cemento portland

    Directory of Open Access Journals (Sweden)

    Janneth Torres Agredo

    2012-06-01

    Full Text Available In this article the possibility of using waste from the petrochemical industry,as partial replacement of Portland cement is studied, evaluating the presenceof contaminants in the waste and the encapsulation, once it is confined on the cement. This has been done, in order to find a use to this residue without cause damage to the environment. This residue, called spent fluid catalytic cracking catalyst (FCC, is mainly formed by a type Y zeolite, which is dispersing in an inorganic oxides matrix. The toxicity characteristic leaching proceeding was applied, in mortars adding with 20% of FCC as Portland cement replacement. The results showed that the residue does not represent a problem from the point of view of the leaching of elements, such as As, Pb, Zn, Cr, and La, which were below to the permissible limits. Additionally, the pozzolanic activity of FCC was evaluated according to ASTM C311, where the efficiency of the residue as pozzolanic addition is demonstrated. With the results the importance of reusing a residue of the petrochemical industry is emphasized, that decreases the amount of cement to be used and improves the mechanical resistance of the materials containing it.En el presente artículo se estudia la posibilidad de utilizar un residuo de la industria petroquímica, como sustitución parcial del cemento Portland, evaluando la presencia de elementos contaminantes en el residuo y su encapsulación, una vez se haya confinado con el cemento. Lo anterior, con el fin de determinar si su uso como material de construcción, puede o no causar un efecto negativo al medio ambiente. El residuo, denominado catalizador usado de craqueo catalítico (FCC, es un material que está compuesto por una zeolita tipo Y, dispersa en una matriz de óxidos inorgánicos. Se aplicó la técnica de TCLP (del inglés Toxicity Characteristic Leaching Procedure, en morteros adicionados con un 20%, de FCC con respecto a la cantidad de cemento. Los resultados

  5. Industry

    International Nuclear Information System (INIS)

    This chapter of the environmental control report deals with the environmental impact of the industry in Austria. It gives a review of the structure and types of the industry, the legal framework and environmental policy of industrial relevance. The environmental situation of the industry in Austria is analyzed in detail, concerning air pollution (SO2, NOx, CO2, CO, CH4, N2O, NH3, Pb, Cd, Hg, dioxin, furans), waste water, waste management and deposit, energy and water consumption. The state of the art in respect of the IPPC-directives (European Integrated Pollution Prevention and Control Bureau) concerning the best available techniques of the different industry sectors is outlined. The application of European laws and regulations in the Austrian industry is described. (a.n.)

  6. Industrialization

    International Nuclear Information System (INIS)

    This chapter discusses the role-plays by nuclear technology to enhance productivity in industry. Some of the techniques, Non-Destructive Testing (NDT) - x, gamma, electron and neutron radiography, nuclear gauges, materials characterization are discussed thoroughly

  7. 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.

  8. Advanced cementation concepts

    International Nuclear Information System (INIS)

    The purpose of this programme of work was to investigate whether improvements could be made to existing formulations for cement suitable for the immobilization of intermediate level radioactive waste. Two additives were selected, microsilica and limestone flour. Improvements to the cement were only slight. (author)

  9. Development of nanosilica bonded monetite cement from egg shells

    International Nuclear Information System (INIS)

    This work represents further effort from our group in developing monetite based calcium phosphate cements (CPC). These cements start with a calcium phosphate powder (MW-CPC) that is manufactured using microwave irradiation. Due to the robustness of the cement production process, we report that the starting materials can be derived from egg shells, a waste product from the poultry industry. The CPC were prepared with MW-CPC and aqueous setting solution. Results showed that the CPC hardened after mixing powdered cement with water for about 12.5 ± 1 min. The compressive strength after 24 h of incubation was approximately 8.45 ± 1.29 MPa. In addition, adding colloidal nanosilica to CPC can accelerate the cement hardening (10 ± 1 min) process by about 2.5 min and improve compressive strength (20.16 ± 4.39 MPa), which is more than double the original strength. The interaction between nanosilica and CPC was monitored using an environmental scanning electron microscope (ESEM). While hardening, nanosilica can bond to the CPC crystal network for stabilization. The physical and biological studies performed on both cements suggest that they can potentially be used in orthopedics. - Highlights: • Cement raw powder is derived from egg shells. • A microwave assisted system is used for preparing monetite bone cement. • Colloidal silica is used to reinforce cement

  10. Development of nanosilica bonded monetite cement from egg shells

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Huan, E-mail: huanzhou@cczu.edu.cn [Institute of Biomedical Engineering and Health Sciences, Changzhou University, Changzhou, Jiangsu (China); Department of Mechanical, Industrial and Manufacturing Engineering, The University of Toledo, Toledo, OH (United States); Luchini, Timothy J.F.; Boroujeni, Nariman Mansouri [Department of Mechanical, Industrial and Manufacturing Engineering, The University of Toledo, Toledo, OH (United States); Agarwal, Anand K.; Goel, Vijay K. [Department of Bioengineering, The University of Toledo, Toledo, OH (United States); Bhaduri, Sarit B. [Department of Mechanical, Industrial and Manufacturing Engineering, The University of Toledo, Toledo, OH (United States); Division of Dentistry, The University of Toledo, Toledo, OH (United States)

    2015-05-01

    This work represents further effort from our group in developing monetite based calcium phosphate cements (CPC). These cements start with a calcium phosphate powder (MW-CPC) that is manufactured using microwave irradiation. Due to the robustness of the cement production process, we report that the starting materials can be derived from egg shells, a waste product from the poultry industry. The CPC were prepared with MW-CPC and aqueous setting solution. Results showed that the CPC hardened after mixing powdered cement with water for about 12.5 ± 1 min. The compressive strength after 24 h of incubation was approximately 8.45 ± 1.29 MPa. In addition, adding colloidal nanosilica to CPC can accelerate the cement hardening (10 ± 1 min) process by about 2.5 min and improve compressive strength (20.16 ± 4.39 MPa), which is more than double the original strength. The interaction between nanosilica and CPC was monitored using an environmental scanning electron microscope (ESEM). While hardening, nanosilica can bond to the CPC crystal network for stabilization. The physical and biological studies performed on both cements suggest that they can potentially be used in orthopedics. - Highlights: • Cement raw powder is derived from egg shells. • A microwave assisted system is used for preparing monetite bone cement. • Colloidal silica is used to reinforce cement.

  11. Use of residual wood in the cement manufacturing process

    International Nuclear Information System (INIS)

    This PowerPoint presentation discussed the use of wood residuals in the cement manufacturing process. An outline of the cement manufacturing process was presented. Raw materials are combined in exact proportions to create a chemically correct mix, which is then pulverized in a mill. The mix is then burned in a kiln. The end product is cooled to form the pellet sized material known as clinker, which is then milled to form cement. The combustion and destruction characteristics of a cement kiln were presented. Modern cement kilns require approximately 3.2 Gj of energy to produce one tonne of cement. It was noted that wood residuals do not contain halogens, sulfur or other materials detrimental to the cement manufacturing process. Possible injection points for kilns were presented. Various studies have shown that wood residuals can be safely used as a fuel in the manufacture of cement. Environmental benefits derived from using wood included the complete destruction of organic portions, and the fact that residual ash becomes an indistinguishable part of the final product. It was concluded that wood residual materials are a satisfactory alternative fuel for the cement industry. tabs., figs

  12. In-situ Mechanical Manipulation of Wellbore Cements as a Solution to Leaky Wells

    Science.gov (United States)

    Kupresan, D.; Radonjic, M.; Heathman, J.

    2013-12-01

    mechanical manipulation (shear stress). The main advantage of this methodology is that mechanical manipulation of cement can induce healing of existing fractures, channels and microannulus seal in a wellbore without introducing new materials (e.g. cement squeeze jobs). Furthermore, this methodology is less sensitive to the influence of downhole conditions such as pressure, temperature and formation fluids, since it uses cement pore water as a medium to alter cement sheath. Based on lab experiments observation, it is possible to perceive that once tested at the industrial scale and if successful, the implementation of this method in the field can potentially mitigate leaky wells in CO2 sequestration projects, wellbores completed for hydraulic-fracturing and other conventional oil and gas producing wells. Key words: Wellbore cement integrity; Leaky wells; Cement microstructures; Casing expansion effect on cement mineralogy alterations.

  13. Tendencias en la segregación residencial en Chile

    Directory of Open Access Journals (Sweden)

    Alan Garín Contreras

    2009-01-01

    Full Text Available Los análisis sobre segregación residencial en Chile, están adquiriendo una importancia creciente, dado que sus efectos sociales son cada vez más evidentes. A objeto de identificar las tendencias que sigue este proceso, se hace una revisión de la investigación a nivel nacional y que permita ser un aporte para el avance en este tema. Los resultados indican que la segregación residencial está disminuyendo, los principales mecanismo que operan en este proceso son: el funcionamiento del mercado del suelo, políticas públicas y los movimientos migratorios al interior de la ciudad.Comoefecto, la segregación ha generado un aumento de los problemas sociales como el alcoholismo, delincuencia, jóvenes solteras embarazadas y deserción escolar. También se observa una predominancia de estudios cuantitativos y una significativa heterogeneidad en el uso de indicadores, como un escaso análisis sobre la percepción y autopercepción de los habitantes de barrios segregados.

  14. Behavior of limestone filler cement mortars exposed to magnesium sulfate attack

    OpenAIRE

    Senhadji Y.; Mouli M.; Escadeillas G.; Khelafi A.; Bennosman A. S.; Chihaoui R.

    2014-01-01

    In the cement production industry, looking for a less expensive binder using industrial waste and natural resources has become a major concern for the deficit level in the manufacture of Portland cement. However, despite the technical, economic and environmental benefits brought by the use of blended cements, they are associated with disadvantages. The objective of this paper is to study the effects of the incorporation of limestone fillers on the mechanical properties and durability of morta...

  15. Tympanoplasty with ionomeric cement

    DEFF Research Database (Denmark)

    Kjeldsen, A D; Grøntved, A M

    2000-01-01

    isolated erosion of the long incus process have been treated with a new surgical technique in which the ossicular chain was rebuilt with ionomeric cement. The results in hearing performance (mean pure-tone average (PTA) 0.5, 1 and 2 kHz) were evaluated pre- and post-surgery, and compared to those in a...... > 10 dB, in 4 there was a slight improvement and in 2 a decline. The difference was not statistically significant. Hearing improvement using ionomeric cement in type II tympanoplasty was satisfactory. Reconstruction of the ossicular chain with ionomeric cement is recommended, as the procedure is easy...

  16. 77 FR 42367 - National Emission Standards for Hazardous Air Pollutants for the Portland Cement Manufacturing...

    Science.gov (United States)

    2012-07-18

    ... that there are 24 cement kilns which combust solid waste. See 76 FR 28322 and Memorandum ``Combustion... reclassifying some cement kilns as commercial and industrial solid waste incinerators (CISWI) and thus could..., the EPA is doing so by removing all kilns classified as commercial and industrial solid...

  17. Destruction of meat and bone meals in cement plants; Destruction des farines animales dans les cimenteries

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2001-10-01

    Following the crisis of the bovine spongiform encephalopathy disease ('mad cow' disease), the French cement industrialists have been requested by the government since 1996 to eliminate the forbidden meat and bone meals in cement kilns where they are used as fuel substitutes. This article presents the advantages of the cement industry file in the destruction of such wastes, the validation and the safety aspects of this process. Meat and bone meal represents a high-grade fuel that lowers the environmental impact of cement production and does not affect the quality of cement. (J.S.)

  18. Modified-sulfur cements for use in concretes, flexible pavings, coatings, and grouts

    Science.gov (United States)

    McBee, W. C.; Sullivan, T. A.; Jong, B. W.

    1981-05-01

    A family of modified-sulfur cements was developed for the preparation of construction materials with improved properties. Various types of sulfur cements were prepared by reacting sulfur with mixtures of dicyclopentadiene and oligomers of cyclopentadiene. Durable cements were prepared with structural characteristics ranging from rigid to flexible. These cements were used to prepare corrosion-resistant materials for use in a wide variety of industrial applications where resistance to acidic and salt conditions is needed. These materials were prepared as rigid concretes, flexible pavings, spray coatings, and grouts. Production of modified-sulfur cements in a commercial-size plant was demonstrated.

  19. Factors affecting bond cement across casing leak zones in oil and gas wells

    Energy Technology Data Exchange (ETDEWEB)

    Nasr, Mohamed; Edbeib, Said [Al-Fateh University, Tripoli (Libyan Arab Jamahiriya). Dept. of Petroleum Engineering

    2004-07-01

    Casing leaks have been a major concern to the oil industry because of their effect on lowering the production rate in many oil and gas wells. The leaks are the result of deterioration of the casing in the well, which is caused by severe corrosion due to the contact of the casing with high salinity foreign fluid. The objective of this study is to determine the factors influencing the mechanical properties of the hardened cement opposite the casing leak zones. This study is conducted by laboratory measurements of the compressive strength of the hardened cement when the cement slurry was mixed with different percentages of formation water and different concentrations of different cement additives. The results of this study indicate that the compressive strength readings obtained from the cement bond log and the cement evaluation tool against the casing leak zones are lower than those readings recorded in adjacent formations. The low cement compressive strength values observed across casing leak zones are due to the contamination of the cement with saline water present in these formations which, in turn, effects the hardening properties of the cement. The experimental results indicated that the salinity of the formation water when mixed with the cement slurry in the presence of cement additives, decreased the compressive strength of the bond cement and also decreased the thickening time of the cement slurry. It is concluded that casing leaks found in many wells observed in oil fields in Libya were due to the mixing of the cement with high salinity formation water present in the lost circulation zones. The high water salinity in these zones effects the setting time of the cement slurry which, therefore, decreased the hardening properties of the bond cement and caused cracks and channels in the hardened cement across lost circulation zones. (author)

  20. Utilization from Cement Kiln Dust in Removal of Acid Dyes

    Directory of Open Access Journals (Sweden)

    Mohamed E.S.I. Saraya

    2012-01-01

    Full Text Available Problem statement: The growth of industries and day to day changes in human activities has resulted in an increase in the volume and complexity of wastewater to the environment. Textile industry is one of the most water consumers industries of Egypt, thus discharges large amounts of wastewater effluents during processing, especially, in the coloring and washing steps. Cement kiln dust is a solid waste in cement manufacturing. Approximately 2.5-3.0 (6-9% million tons of cement kiln dust is produced annually in Egypt and that cause significant environmental problems. Approach: This study aims to investigate removal of some acid dyes from aqueous solution using cement kiln dust and monitoring the dye in colored cement kiln dust. Solution with 0.4 g L-1 concentration was treated with cement kiln dust until the color of dye disappears. The colored cement kiln residue was separate by filtration and dried. The concentration of dye was measured before and after treatment by UV-Vis spectroscopy as well as after washing of colored residue. Also, the colored residue was investigated with, XRD, IR and DSC techniques as well as the loss on ignition at 450°C. Results: The results found that the cement kiln dust has the power to remove all existing acid dyes and the residue has the same color of dye. When colored residue was washed with water, there was no back diffusion of dye in to water. This may be mainly due to chemical reaction that took place between cement kiln dust and dye. Thus analysis such as IR, XRD and DSC are in agreement with these results. Conclusion: CKD is efficient in the processes of dye removal from aqueous solutions. The interaction between acid dye and CKD is fast (just minutes. So, we suggest using spent CKD for dye removal of waste water.

  1. Energy optimization and reduction of carbon footprint in cement manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Gallestey, Eduardo; Crosley, Gabriela; Wilson, Andrew; Maier, Urs; Hoppler, Rolf; Boerrnert, Thomas

    2010-09-15

    Cement producers are large consumers of thermal and electrical energy, which are only available at steadily increasing costs. Efforts to reduce demands by using higher efficiency equipment and substituting -fuels and raw materials to lower production costs have been addressed in recent years. Under the Kyoto Protocol industrialised countries agreed to reduce their collective greenhouse gas emissions. Cement producers as some of the largest emitters of CO2 have been especially challenged to find new and innovative ways to reduce greenhouse gas emissions. This paper summarise some ABB technologies developed to assist the cement industry to meet these goals.

  2. Analysis of cement superplasticizers and grinding aids a literature survey

    International Nuclear Information System (INIS)

    This literature survey reviews the methods for analysis of cement plasticizers and organic grounding aids in cement solutions in preparation of grouts/concrete and methods for determination of plasticizers and grinding aids in groundwater conditions. The survey focuses on three different types of superplasticizers: sulphonated naphthalene condensates, sulphonated melamine condensates and polycarboxylates. There are various organic grinding aids, such as alkanolamines, glycols or phenolic compounds, used in the cement industry. This review is concerned with the following compounds: triethylenetetramine, tetraethylenepentamine, diethanolamine, triethanolamine, triisopropanolamine, ethyleneglycol, diethyleneglycol, aminoethylethanolamine, hydroxyethyl diethylenetriamine and phenol. (orig.)

  3. The effect of fly ash and coconut fibre ash as cement replacement materials on cement paste strength

    Science.gov (United States)

    Bayuaji, R.; Kurniawan, R. W.; Yasin, A. K.; Fatoni, H. AT; Lutfi, F. M. A.

    2016-04-01

    Concrete is the backbone material in the construction field. The main concept of the concrete material is composed of a binder and filler. Cement, concrete main binder highlighted by environmentalists as one of the industry are not environmentally friendly because of the burning of cement raw materials in the kiln requires energy up to a temperature of 1450° C and the output air waste CO2. On the other hand, the compound content of cement that can be utilized in innovation is Calcium Hydroxide (CaOH), this compound will react with pozzolan material and produces additional strength and durability of concrete, Calcium Silicate Hydrates (CSH). The objective of this research is to explore coconut fibers ash and fly ash. This material was used as cement replacement materials on cement paste. Experimental method was used in this study. SNI-03-1974-1990 is standard used to clarify the compressive strength of cement paste at the age of 7 days. The result of this study that the optimum composition of coconut fiber ash and fly ash to substitute 30% of cement with 25% and 5% for coconut fibers ash and fly ash with similar strength if to be compared normal cement paste.

  4. Effect of Duration of Exposure to Cement Dust on Respiratory Function of Non-Smoking Cement Mill Workers

    Science.gov (United States)

    Meo, Sultan Ayoub; Al-Drees, Abdul Majeed; Al Masri, Abeer A.; Al Rouq, Fawzia; Azeem, Muhammad Abdul

    2013-01-01

    This study aimed to determine the effect of long term exposure to cement dust on lung function in non-smoking cement mill workers. This is a cross-sectional study of respiratory functions. Spirometry was performed in 100 apparently healthy volunteers; 50 non-smoking cement mill workers and 50 non-smoking un-exposed subjects. Based on the duration of exposure, cement mill workers were divided into three groups, less than 5, 5–10 and greater than 10 years. All subjects were individually matched for age, height, weight, and socioeconomic status. Pulmonary function test was performed by using an electronic spirometer. Significant reduction was observed in the mean values of Forced Vital Capacity (FVC), Forced Expiratory Volume in one second (FEV1), Peak Expiratory Flow (PEF) and Maximal Voluntary Ventilation in cement mill workers who had been working in the cement industry for more than 10 years compared to their matched un-exposed group. Lung functions in cement mill workers were significantly impaired and results show a long term duration response effect of years of exposure to cement dust on lung functions. PMID:23325026

  5. Effect of Duration of Exposure to Cement Dust on Respiratory Function of Non-Smoking Cement Mill Workers

    Directory of Open Access Journals (Sweden)

    Fawzia Al Rouq

    2013-01-01

    Full Text Available This study aimed to determine the effect of long term exposure to cement dust on lung function in non-smoking cement mill workers. This is a cross-sectional study of respiratory functions. Spirometry was performed in 100 apparently healthy volunteers; 50 non-smoking cement mill workers and 50 non-smoking un-exposed subjects. Based on the duration of exposure, cement mill workers were divided into three groups, less than 5, 5–10 and greater than 10 years. All subjects were individually matched for age, height, weight, and socioeconomic status. Pulmonary function test was performed by using an electronic spirometer. Significant reduction was observed in the mean values of Forced Vital Capacity (FVC, Forced Expiratory Volume in one second (FEV1, Peak Expiratory Flow (PEF and Maximal Voluntary Ventilation in cement mill workers who had been working in the cement industry for more than 10 years compared to their matched un-exposed group. Lung functions in cement mill workers were significantly impaired and results show a long term duration response effect of years of exposure to cement dust on lung functions.

  6. Use of Oscillatory Shear to Study the Effect of Limestone Filler on the Rheology of Early-Age Portland Cement

    OpenAIRE

    Barney, Christopher W; Erk, Kendra

    2013-01-01

    Cement is a material that has been in use since the ancient times and is the most widely manufactured material in industry today. During the production of cement, limestone undergoes a process called calcination which releases CO2. In order to reduce the environmental impact and cost of cement production it has become standard practice to replace a portion of the cement mixture with ground limestone, but this causes a change in the rheological profile of the mixture. This change in rheology a...

  7. Design of Digital Control System for Cement Raw Material Preparation

    Institute of Scientific and Technical Information of China (English)

    ZHOU Ying; LI Hongsheng

    2006-01-01

    This paper describes the design of cement raw material prepared digital control system by PROFIBUS. It uses the digital technology to implement the digital control system for raw material prepared of the cement factory. This system improves the communication between the industrial system and locale instrument devices. It applies digital communication to replace the 4-20 mA or 24VDC signal between locale lever device and controller.

  8. Development of Production Technologies for Universal Hydraulic Cement (UHC)

    OpenAIRE

    Syal, Dr. S K

    2013-01-01

    It is based on our recent approaches of Modern construction materials utilizing existing wastes such as fly ashes slags and to save energies by technological developments.The article is essential in the direction of new materials called Durable Integral polymer-pigmented cement concretes. UHC is calcium aluminate cements with natural properties of durable earth materials. It is a step towards Research for Innovation in Indian Industries

  9. The asbestos cement container and its characterization program

    International Nuclear Information System (INIS)

    A new type of packing container is designed in France, by SGN, for the reprocessing wastes conditioning: the asbestos cement container (CAC) made by the industrial process for pipes fabrication. Two types of CAC are studied, differing from each other by their wall thickness. The technology of which SGN is in charge is presented. A characterization program is operated by CEA in view of satisfying to regulatory requirements. Emphasis is placed upon the radionuclides migration study, through different asbestos cement samples

  10. Bleeding and Filtration of Cement-Based Grout

    OpenAIRE

    Draganovic, Almir

    2009-01-01

    Grouting is a common method of sealing rock around tunnels to reduce or stop water inflow. Successful grouting significantly minimizes the maintenance cost and safety of the tunnel. Some questions about bleeding and penetrability of the grouts have to be examined more closely to carry out a successful grouting. Bleeding of cement-based grout is a complex problem. Measuring methods used today originate from the measuring of the bleeding of cement pastes used in ordinary building industry. Whet...

  11. Hydration and dimensional stability of calcium aluminate cement based systems

    OpenAIRE

    Bizzozero, Julien

    2014-01-01

    Calcium aluminate cements (CAC) are often used in combination with calcium sulfate and Portland cement for special applications where rapid setting, rapid drying and shrinkage compensation are required. A growing fraction of the clinker, which has the highest CO2 intensity, is being replaced by supplementary cementitious materials (SCM). These SCM are usually from industrial by-products such as slag, fly ashes or can simply be raw materials such as limestone. This project aims at replacing th...

  12. Fabrication of Phosphate Cement with High Integrity

    International Nuclear Information System (INIS)

    As the development of industrial society has accelerated, hazardous wastes are generated as well. According to the 1986 statistics of U.S.A, each person made 40 tons of waste in America that year. Treatment of radioactive waste is one of the most important and serious problems related to waste treatments, because its radioactivity and decaying heat have harmful effects to human and environment for a long time. Nuclear developed countries have used conventional method of treatment such as vitrification or cementation in order to stabilize and solidify radioactive waste. Although the former guarantees the formation of high leaching resistant and durable waste form, it requires several hundred (or even more than one thousand) temperature to melt glass frit. This process generates secondary waste volatilized, as well as being non-economical. Cement technology played a role of immobilizing low and middle class wastes. It has advantages of low temperature setting, low cost, easy process, etc. The alkalinity of ordinary cement, however, constrains the utility of cement to the solidification of alkaline waste. In addition, leachability and mechanical strength of cements are not quite appropriate for the stabilization of high level waste. In this regard, chemically bonded phosphate cement(CBPC), which sets by an acid-base reaction, is a potentially expectable material for immobilization of radioactive waste. CBPC not only sets at room temperature, but also encapsulates various isotopes chemically. The performance of CBPC can be enhanced by the addition of fly ash, sand, wollastonite, etc. This study aims at fabricating the CBPC containing fly ash with high integrity. Morphology, microstructure, and compressive strength are evaluated using SEM, and digital compressing machine

  13. Fabrication of Phosphate Cement with High Integrity

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jae Hwan; Lee, Chang Hwa; Heo, Cheol Min; Jeon, Min Ku; Kang, Kweon Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2011-05-15

    As the development of industrial society has accelerated, hazardous wastes are generated as well. According to the 1986 statistics of U.S.A, each person made 40 tons of waste in America that year. Treatment of radioactive waste is one of the most important and serious problems related to waste treatments, because its radioactivity and decaying heat have harmful effects to human and environment for a long time. Nuclear developed countries have used conventional method of treatment such as vitrification or cementation in order to stabilize and solidify radioactive waste. Although the former guarantees the formation of high leaching resistant and durable waste form, it requires several hundred (or even more than one thousand) temperature to melt glass frit. This process generates secondary waste volatilized, as well as being non-economical. Cement technology played a role of immobilizing low and middle class wastes. It has advantages of low temperature setting, low cost, easy process, etc. The alkalinity of ordinary cement, however, constrains the utility of cement to the solidification of alkaline waste. In addition, leachability and mechanical strength of cements are not quite appropriate for the stabilization of high level waste. In this regard, chemically bonded phosphate cement(CBPC), which sets by an acid-base reaction, is a potentially expectable material for immobilization of radioactive waste. CBPC not only sets at room temperature, but also encapsulates various isotopes chemically. The performance of CBPC can be enhanced by the addition of fly ash, sand, wollastonite, etc. This study aims at fabricating the CBPC containing fly ash with high integrity. Morphology, microstructure, and compressive strength are evaluated using SEM, and digital compressing machine

  14. Clean Development Mechanism: Laterite as Supplementary Cementing Material (SCM)

    OpenAIRE

    Syed Zaighum Abbass; Syed Shahid Ali; Jabar Zaman Khan Khattak; Zubair Anwar

    2013-01-01

    Carbon dioxide (CO2) a major Green House Gas (GHG) in the atmosphere, is believed to be largely responsible for global climate change through industrial emissions. The level of CO2 concentration has exponentially increased from about 280 ppm at the start of the industrial revolution to about 380 ppm to date. Although Kyoto protocol has bound industrialized nations to reduce green house gas emissions by 5.2% below 1990 levels around year 2008-2012, but violation continues. The cement industry ...

  15. ULTRA-LIGHTWEIGHT CEMENT

    Energy Technology Data Exchange (ETDEWEB)

    Fred Sabins

    2001-10-23

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). Work reported herein addresses tasks performed in the fourth quarter as well as the other three quarters of the past year. The subjects that were covered in previous reports and that are also discussed in this report include: Analysis of field laboratory data of active cement applications from three oil-well service companies; Preliminary findings from a literature review focusing on problems associated with ultra-lightweight cements; Summary of pertinent information from Russian ultra-lightweight cement literature review; and Comparison of compressive strengths of ULHS systems using ultrasonic and crush methods Results reported from the fourth quarter include laboratory testing of ULHS systems along with other lightweight cement systems--foamed and sodium silicate slurries. These comparison studies were completed for two different densities (10.0 and 11.5 lb/gal) and three different field application scenarios. Additional testing included the mechanical properties of ULHS systems and other lightweight systems. Studies were also performed to examine the effect that circulation by centrifugal pump during mixing has on breakage of ULHS.

  16. PART II. HYDRATED CEMENTS

    Directory of Open Access Journals (Sweden)

    Milan Drabik

    2014-09-01

    Full Text Available Essential focus of the study has been to acquire thermoanalytical events, incl. enthalpies of decompositions - ΔH, of technological materials based on two types of Portland cements. The values of thermoanalytical events and also ΔH of probes of technological compositions, if related with the data of a choice of minerals of calcium-silicate-sulfate-aluminate hydrates, served as a valued input for the assessment of phases present and phase changes due to the topical hydraulic processes. The results indicate mainly the effects of "standard humidity" or "wet storage" of the entire hydration/hydraulic treatment, but also the presence of cement residues alongside calcium-silicate-sulfate-aluminate hydrates (during the tested period of treatment. "A diluting" effect of unhydrated cement residues upon the values of decomposition enthalpies in the studied multiphase system is postulated and discussed

  17. Thermal behavior of asphalt cements

    International Nuclear Information System (INIS)

    Asphalt cements are highly complex mixtures of hydrocarbon molecules whose thermal behavior is of prime importance for petroleum and road industry. From DSC, the determination of several thermal properties of asphalts is given, e.g. glass-transition temperature and crystallized fraction content.The dissolution of a pure n-paraffin CnH2n+2 in an asphalt, as seen by DSC, should be a single peak. For 20g of these glasses change with time and temperature. The formation of the crystallized phases is superposed to the enthalpic relaxation of the glasses, making a kinetic study very difficult. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  18. Clean Development Mechanism: Laterite as Supplementary Cementing Material (SCM

    Directory of Open Access Journals (Sweden)

    Syed Zaighum Abbass

    2013-02-01

    Full Text Available Carbon dioxide (CO2 a major Green House Gas (GHG in the atmosphere, is believed to be largely responsible for global climate change through industrial emissions. The level of CO2 concentration has exponentially increased from about 280 ppm at the start of the industrial revolution to about 380 ppm to date. Although Kyoto protocol has bound industrialized nations to reduce green house gas emissions by 5.2% below 1990 levels around year 2008-2012, but violation continues. The cement industry is one of the major emitter of green house gases, particularly CO2 due to its energy intensive production process. It is estimated that approximately 1 tone of CO2 is released during the manufacturing of each tone of Portland cement. Most of CO2 emissions originate from burning fossil fuels and de-carbonization of limestone in a cement plant. During past several decades, the use of by-product materials in concrete, either as components of blended cements or as admixtures, has increased significantly. In this study, another alternate Supplementary Cementing Material (SCM, Laterite has been used with the objectives: to evaluate the performance of cement containing different percentages of laterite (5, 10, 15, 20, 25, and 30 %; to identify the optimum replacement percentage; and to investigate the effects of different concentrations of laterite on various properties of cement. For that purpose, laterite was tested: before blending (for elemental and mineralogical composition by using XRF, SEM and XRD: after blending (Elemental analysis using XRF, fineness test by using Blaine’s air permeability test and for particle size % on 45, 90 and 200 µ sieve, respectively; and after hydration (for mineralogical analysis using SEM. Furthermore, physical tests of manufactured cement, i.e., water consistency, setting time, Le-Chatlier-expansion and compressive strength were also evaluated and compared with limestone and fly-ash cement blends. The results show that with the

  19. Sociedad de la información: análisis de modelos y tendencias

    OpenAIRE

    Crespi Serrano, Albert

    2010-01-01

    Este proyecto, enmarcado en la línea Análisis de la evolución y tendencias futuras de la Sociedad de la Información, persigue analizar la Sociedad de la Información inicialmente desde un punto de vista teórico para descubrir los ámbitos clave que abarca, para posteriormente realizar un análisis más exhaustivo de algunos de los ámbitos escogidos ante la posibilidad de abarcarlos todos. Una vez escogidos los ámbitos a estudiar, se analizarán las tendencias actuales en el mundo sobre estos ámbit...

  20. Concrete = aggregate, cement, water?

    International Nuclear Information System (INIS)

    Concrete for the Temelin nuclear power plant is produced to about 70 different formulae. For quality production, homogeneous properties of aggregates, accurate proportioning devices, technological discipline and systematic inspections and tests should be assured. The results are reported of measuring compression strength after 28 days for different concrete samples. The results of such tests allow reducing the proportion of cement, which brings about considerable savings. Reduction in cement quantities can also be achieved by adding ash to the concrete mixes. Ligoplast, a plasticizer addition is used for improving workability. (M.D). 8 figs

  1. Cementing a wellbore using cementing material encapsulated in a shell

    Energy Technology Data Exchange (ETDEWEB)

    Aines, Roger D.; Bourcier, William L.; Duoss, Eric B.; Spadaccini, Christopher M.; Cowan, Kenneth Michael

    2016-08-16

    A system for cementing a wellbore penetrating an earth formation into which a pipe extends. A cement material is positioned in the space between the wellbore and the pipe by circulated capsules containing the cement material through the pipe into the space between the wellbore and the pipe. The capsules contain the cementing material encapsulated in a shell. The capsules are added to a fluid and the fluid with capsules is circulated through the pipe into the space between the wellbore and the pipe. The shell is breached once the capsules contain the cementing material are in position in the space between the wellbore and the pipe.

  2. The mechanical effect of the existing cement mantle on the in-cement femoral revision.

    LENUS (Irish Health Repository)

    Keeling, Parnell

    2012-08-01

    Cement-in-cement revision hip arthroplasty is an increasingly popular technique to replace a loose femoral stem which retains much of the original cement mantle. However, some concern exists regarding the retention of the existing fatigued and aged cement in such cement-in-cement revisions. This study investigates whether leaving an existing fatigued and aged cement mantle degrades the mechanical performance of a cement-in-cement revision construct.

  3. Modelling for integrated energy optimisation in cement production plants / J.A. Swanepoel.

    OpenAIRE

    Swanepoel, Jan Adriaan

    2013-01-01

    Cement production is an energy intensive process. In South Africa the cost of energy increased since 2006, while cement sales have dropped dramatically. It has become important to focus on methods to optimise energy consumption to achieve cost savings in the cement industry. Various methods of reducing production cost by improving energy efficiency are available, but require extended installation periods and high initial capital expenditure. Other methods such as operational optimisation can ...

  4. Utilization of Iron Ore Tailings as Raw Material for Portland Cement Clinker Production

    OpenAIRE

    Li Luo; Yimin Zhang; Shenxu Bao; Tiejun Chen

    2016-01-01

    The cement industry has for some time been seeking alternative raw material for the Portland cement clinker production. The aim of this research was to investigate the possibility of utilizing iron ore tailings (IOT) to replace clay as alumina-silicate raw material for the production of Portland cement clinker. For this purpose, two kinds of clinkers were prepared: one was prepared by IOT; the other was prepared by clay as a reference. The reactivity and burnability of raw meal, mineralogical...

  5. Comparative Study of Clinker's Transformation 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

    Chemical composition analysis using x-ray fluorescence is one of the important quality analysis for examining of cement and widely used in cement industries for a long time as a tool to estimate phase composition. X-ray diffraction is one of the established techniques as a qualitative tool to identify phase existing in the sample. This study will discuss about the correlation between quantitative and qualitative analyses in order to understand phase transformation in production of cement. Qua...

  6. Application of Carbonate Looping to Cement Industry

    DEFF Research Database (Denmark)

    Lin, Weigang; Illerup, Jytte Boll; Dam-Johansen, Kim;

    2012-01-01

    sorbents in carbonate looping processes. The results show that the CO2 carrying capacity of limestone is much lower at realistic conditions than at mild conditions, which are often used in laboratory experiments. BET and SEM analyses show that the surface area of calcined limestone decreases significantly...

  7. PURIFIED WASTE FCC CATALYST AS A CEMENT REPLACEMENT MATERIAL

    Directory of Open Access Journals (Sweden)

    Danute Vaiciukyniene

    2015-06-01

    Full Text Available Zeolites are commonly used in the fluid catalytic cracking process. Zeolite polluted with oil products and became waste after some time used. The quantity of this waste inevitably rises by expanding rapidly oil industry. The composition of these catalysts depends on the manufacturer and on the process that is going to be used. The main factors retarding hydration process of cement systems and modifying them strength are organic compounds impurities in the waste FCC catalyst. The present paper shows the results of using purified waste FCC catalyst (pFCC from Lithuania oil refinery, as Portland cement replacement material. For this purpose, the purification of waste FCC catalyst (FCC samples was treated with hydrogen peroxide. Hydrogen peroxide (H2O2 is one of the most powerful oxidizers known. By acting of waste with H2O2 it can eliminate the aforementioned waste deficiency, and the obtained product becomes one of the most promising ingredients, in new advanced building materials. Hardened cement paste samples with FCC or pFCC were formed. It was observed that the pFCC blended cements developed higher strength, after 28 days, compared to the samples with FCC or reference samples. Typical content of Portland cement substituting does not exceed 30 % of mass of Portland cement in samples. Reducing the consumption of Portland cement with utilizing waste materials is preferred for reasons of environmental protection.

  8. The FGM Concept in the Development of Fiber Cement Components

    International Nuclear Information System (INIS)

    The FGM concept appears promising in improving the mechanical performance and reducing production costs of fiber cement building components. However, it has not yet been broadly applied to fiber cement technology. In this study we analyze the functionally graded fiber cement concept and its potential for industrial application in Hatschek machines. The conventional Hatschek process is summarized as well as the proposed modifications to allow FGM fiber cement production. The feasibility of producing functionally graded fiber cement by grading PVA fiber content was experimentally evaluated. Thermogravimetric (TG) and Scanning Electron Microscope (SEM) analysis were used to evaluate fiber distribution profiles. Four-point bending tests were applied to evaluate the mechanical performance of both conventional and functionally graded composites. The results shows that grading PVA fiber content is an effective way to produce functionally graded fiber cement, allowing the reduction of the total fiber volume without significant reduction on composite MOR. TG tests were found adequate to assess fiber content at different positions in functionally graded fiber cements

  9. Utilization of Palm Oil Clinker as Cement Replacement Material

    Directory of Open Access Journals (Sweden)

    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.

  10. Preterm delivery among people living around Portland cement plants.

    Science.gov (United States)

    Yang, Chun-Yuh; Chang, Chih-Ching; Tsai, Shang-Shyue; Chuang, Hung-Yi; Ho, Chi-Kung; Wu, Trong-Neng; Sung, Fung-Chang

    2003-05-01

    The Portland cement industry is the main source of particulate air pollution in Kaohsiung city. Data in this study concern outdoor air pollution and the health of individuals living in communities in close proximity to Portland cement plants. The prevalence of delivery of preterm birth infants was significantly higher in mothers living within 0-2 km of a Portland cement plant than in mothers living within 2-4 km. After controlling for several possible confounders (including maternal age, season, marital status, maternal education, and infant sex), the adjusted odds ratio was 1.30 (95% CI=1.09-1.54) for the delivery of preterm infants for mothers living close to the Portland cement plants, chosen at the start to be from 0 to 2 km. These data provide further support for the hypothesis that air pollution can affect the outcome of pregnancy. PMID:12706757

  11. Preterm delivery among people living around Portland cement plants

    International Nuclear Information System (INIS)

    The Portland cement industry is the main source of particulate air pollution in Kaohsiung city. Data in this study concern outdoor air pollution and the health of individuals living in communities in close proximity to Portland cement plants. The prevalence of delivery of preterm birth infants as significantly higher in mothers living within 0-2 km of a Portland cement plant than in mothers living within 2-4 km. After controlling for several possible confounders (including maternal age, season, marital status, maternal education, and infant sex), the adjusted odds ratio was 1.30 (95% I=1.09-1.54) for the delivery of preterm infants for mothers living close to he Portland cement plants, chosen at the start to be from 0 to 2 km. These data provide further support for the hypothesis that air pollution can affect he outcome of pregnancy

  12. Advanced cement solidification technique for spent resins

    International Nuclear Information System (INIS)

    In the past 40 years, the nuclear facilities of China Institute of Atomic Energy (CIAE) produced an amount of radioactive organic resins, a kind of problematic stream in nuclear industry. As these facilities were stepping into decommissioning, the treatment of the spent organic resins was put on the agenda. The various routes for spent resin treatment such as incineration, advanced oxidation, cement immobilization, etc, were considered. Each method has its advantages and disadvantages when applied in the treatment of spent resins. Since the quantities of the spent organic resins were relatively small and an experience with variety of cementation processes existed in CIAE, predominately for immobilization of the evaporated concentrates, the option of direct encapsulation of the spent organic resins into cementitious materials was adopted in 2003, as a preferred method from the point of view of saving the on the cost of the disposal. In order to realize the end goal, the main work consisted of: the survey of the source terms; cementitious material formula investigation; and the process development. This work, which was undertaken in the following years, is addressed as follows. Source terms of the spent resins in CIAE were to be made clear firstly. The results showed that a total of 24-29 m3 of spent resins was generated and accumulated in the past 40 years. Spent resin arose from two research reactors (heavy water reactor and light water reactor), and from the waste management plant. The amount of the spent resins from the heavy water reactor was 1m3 or so, but its radioactive concentration was high to ∼108-∼109Bq/m3. Two kinds of cements, ASC and OPC cement were selected next, as the solidifying matrix to be investigated. A mixture surface response approach was employed to design experiment and interpret data. In comparison, ASC was superior to OPC cement and it displayed preferable performances to encapsulate spent resins. The optimum formulation is:1) resin

  13. Calidad de las aguas superficiales en la Cuenca del Ebro. Tendencias de salinidad, nitrato y fosfato

    OpenAIRE

    Quílez Sáez de Viteri, Dolores

    2011-01-01

    Objetivo General: Caracterización de la calidad de las aguas superficiales de la Cuenca del Ebro y de sus tendencias. Redes de Control de Calidad de Aguas de CHE: - 497 estaciones de control - Datos instantáneos con frecuencias variables - Se han seleccionado 31 estaciones - Relevancia dentro de la Cuenca del Ebro - Predominio del regadío - Disponibilidad de datos

  14. Utilization of Palm Oil Clinker as Cement Replacement Material

    OpenAIRE

    Jegathish Kanadasan; Hashim Abdul Razak

    2015-01-01

    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 pa...

  15. Mergers and acquisitions : the case of Cimpor and InterCement

    OpenAIRE

    Andrade, Miguel Luís

    2014-01-01

    In June of 2012 Camargo Corrêa, the Brazilian Family Group that controlled the Brazilian cement producer InterCement, acquired 61% of the Portuguese cement production leader, Cimpor, with an offer price of 5.5 Euros, allowing Camargo Corrêa to take full control of Cimpor by owning 94% of the company. Cement is an industry characterized by huge production scales and high initial investments, with an enduring trend of consolidation among cement’s biggest international producers, and this dea...

  16. Effect of Heavy Metal Present in Cement Dust on Soil and Plants of Nokha (Bikaner

    Directory of Open Access Journals (Sweden)

    Dr.(Mrs.Suruchi Gupta

    2013-08-01

    Full Text Available In Nokha(Bikaner cement industries emittes cement dust in nearby farmers fields. In these industries cement dust emitted contains traces of hexavalent chromium and lead well above permissible limit in area under investigation. However, cadmium and nickel were found below limits prescribed. To analyse heavy metals viz, Cr+6, lead, Cadmium and nickel one hundred and twenty samples were collected from four directions on surface and 20 cm depth, and analyzed on atomic absorption spectrophotometer. From the above study it is clear that in case of Sarvottam cement works only lead content was higher in all directions and depths than other two plants. At tiger and Nokha cement works contamination of lead was more over limited in the first 1 km except in east direction. Mobility of lead was relatively more on top soil than 20cm depth. Hexavalent chromium content in south western direction was more for Nokha cement. Whereas, it was more in east direction in case of tiger cement. This indicated influence of prevailing direction of wind on distribution of heavy metals present in cement dust.Heavy metal toxicity results in reduction in plant height, burning of leaf margins and tip, slow leaf growth and over all wilting of Prosopis cineraria, Pearlmillet and clusterbean plants, when this metal deposits in Human body results in genetic disorders. Electrostatic precipitator can be installed to reduce the cement dust emission.

  17. Estimation of CO2 emissions from China’s cement production: Methodologies and uncertainties

    International Nuclear Information System (INIS)

    In 2010, China’s cement output was 1.9 Gt, which accounted for 56% of world cement production. Total carbon dioxide (CO2) emissions from Chinese cement production could therefore exceed 1.2 Gt. The magnitude of emissions from this single industrial sector in one country underscores the need to understand the uncertainty of current estimates of cement emissions in China. This paper compares several methodologies for calculating CO2 emissions from cement production, including the three main components of emissions: direct emissions from the calcination process for clinker production, direct emissions from fossil fuel combustion and indirect emissions from electricity consumption. This paper examines in detail the differences between common methodologies for each emission component, and considers their effect on total emissions. We then evaluate the overall level of uncertainty implied by the differences among methodologies according to recommendations of the Joint Committee for Guides in Metrology. We find a relative uncertainty in China’s cement-related emissions in the range of 10 to 18%. This result highlights the importance of understanding and refining methods of estimating emissions in this important industrial sector. - Highlights: ► CO2 emission estimates are critical given China’s cement production scale. ► Methodological differences for emission components are compared. ► Results show relative uncertainty in China s cement-related emissions of about 10%. ► IPCC Guidelines and CSI Cement CO2 and Energy Protocol are recommended

  18. Tympanoplasty with ionomeric cement.

    Science.gov (United States)

    Kjeldsen, A D; Grøntved, A M

    2000-01-01

    Patients with isolated erosion of the long incus process suffer from severe hearing loss caused by lack of continuity of the ossicular chain. This study is a retrospective evaluation of the hearing results using two different surgical procedures. Since January 1993, 12 consecutive patients with isolated erosion of the long incus process have been treated with a new surgical technique in which the ossicular chain was rebuilt with ionomeric cement. The results in hearing performance (mean pure-tone average (PTA) 0.5, 1 and 2 kHz) were evaluated pre- and post-surgery, and compared to those in a group of 20 historical controls who underwent surgery in 1991 and 1992 using incus autograft interposition. Among the 12 index patients, 7 (58%) achieved improvement in PTA of > 10 dB, in 3 there was no difference and in 2 a slight decline. Among the 20 controls, 14 (70%) achieved improvement in PTA of > 10 dB, in 4 there was a slight improvement and in 2 a decline. The difference was not statistically significant. Hearing improvement using ionomeric cement in type II tympanoplasty was satisfactory. Reconstruction of the ossicular chain with ionomeric cement is recommended, as the procedure is easy to perform, presents less risk of damage to the stapes and cochlea, requires less extensive surgery and does not exclude other surgical methods in cases of reoperation. PMID:10909000

  19. Hydration study of limestone blended cement in the presence of hazardous wastes containing Cr(VI)

    International Nuclear Information System (INIS)

    Considering the increasing use of limestone cement manufacture, the present paper tends to characterize limestone behavior in the presence of Cr(VI). The research reported herein provides information regarding the effect of Cr(VI) from industrial wastes in the limestone cement hydration. The cementitious materials were ordinary Portland cement, as reference, and limestone blended cement. The hydration and physicomechanical properties of cementitious materials and the influence of chromium at an early age were studied with X-ray diffraction (XRD), infrared spectroscopy (FTIR), conductimetric and mechanical tests. Portland cement pastes with the addition of Cr(VI) were examined and leaching behavior with respect to water and acid solution were investigated. This study indicates that Cr(VI) modifies the rate and the components obtained during the cement hydration

  20. Copper-promoted cementation of antimony in hydrochloric acid system: A green protocol.

    Science.gov (United States)

    Wu, Lian-Kui; Li, Ying-Ying; Cao, Hua-Zhen; Zheng, Guo-Qu

    2015-12-15

    A new method of recovering antimony in hydrochloric acid system by cementation with copper powder was proposed and carried out at laboratory scale. Thermodynamic analysis and cyclic voltammetry test were conducted to study the cementation process. This is a novel antimony removal technology and quite meets the requirements of green chemistry. The main cement product Cu2Sb is a promising anodic material for lithium and sodium ion battery. And nearly all consumed copper powder are transformed into CuCl which is an important industrial material. The effect of reaction temperature, stoichiometric ratio of Cu to Sb(III), stirring rate and concentration of HCl on the cementation efficiency of antimony were investigated in detail. Optimized cementation condition is obtained at 60 °C for 120 min and stirring rate of 600 rpm with Cu/Sb(III) stoichiometric ratio of 6 in 3 mol L(-1) HCl. At this time, nearly all antimony can be removed by copper powder and the cementation efficiency is over 99%. The structure and morphologies of the cement products were characterized by X-ray diffraction and scanning electron microscopy, respectively. Results show that the reaction temperature has little influence on the morphology of the cement products which consist of particles with various sizes. The activation energy of the cementation antimony on copper is 37.75 kJ mol(-1), indicating a chemically controlled step. Inductively coupled plasma mass spectrometry results show that no stibine generates during the cementation process. PMID:26252996

  1. Carbonate Looping for De-Carbonization of Cement Plants

    DEFF Research Database (Denmark)

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

    2011-01-01

    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) to...... capture emitted CO2 and 2) to generate power for internal use, because high quality energy can be recovered from carbonate looping which is operated at high temperature unlike amine process. A simple carbonate looping process model was developed based on average conversion of calcined limestone defined by...... calciner capacity is also investigated. The results from this simple model show the importance of cement industry to the carbon capture technology for its application to power plants....

  2. [Haemotoxicity of dental luting cements].

    Science.gov (United States)

    Anders, A; Welker, D

    1989-06-01

    A glass ionomer luting cement (AquaCem) shows a relatively low haemolytic activity in comparison with two zinc phosphate cements. Especially the initial irritation by this cement is smaller. Although it is possible that AquaCem particularly, in unfavourable cases, may damage the pulpa dentin system; this is due to the slowly decrease of the haemolytic activity with increasing of the probes. We found that Adhesor showed in dependence of the batches a varying quality. PMID:2626769

  3. Cement penetration after patella venting.

    Science.gov (United States)

    Jones, Christopher W; Lam, Li-On; Butler, Adam; Wood, David J; Walsh, William R

    2009-01-01

    There is a high rate of patellofemoral complications following total knee arthroplasty. Optimization of the cement-bone interface by venting and suction of the tibial plateau has been shown to improve cement penetration. Our study was designed to investigate if venting the patella prior to cementing improved cement penetration. Ten paired cadaver patellae were allocated prior to resurfacing to be vented or non-vented. Bone mineral density (BMD) was measured by DEXA scanning. In vented specimens, a 1.6 mm Kirschner wire was used to breach the anterior cortex at the center. Specimens were resurfaced with standard Profix instrumentation and Versabond bone cement (Smith and Nephew PLC, UK). Cement penetration was assessed from Faxitron and sectioned images by a digital image software package (ImageJ V1.38, NIH, USA). Wilcoxon rank sum test was used to assess the difference in cement penetration between groups. The relationship between BMD and cement penetration was analyzed by Pearson correlation coefficient. There was a strong negative correlation between peak BMD and cement penetration when analyzed independent of experimental grouping (r(2)=-0.812, p=0.004). Wilcoxon rank sum testing demonstrated no significant difference (rank sum statistic W=27, p=0.579) in cement penetration between vented (10.53%+/-4.66; mean+/-std dev) and non-vented patellae (11.51%+/-6.23; mean+/-std dev). Venting the patella using a Kirschner wire does not have a significant effect on the amount of cement penetration achieved in vitro using Profix instrumentation and Versabond cement. PMID:19010682

  4. Study of technical and financial pre-feasibility for the handling and sale, as fuel in cement industries, of petroleum coke produced at a petroleum refinery located in Moin, Limon

    International Nuclear Information System (INIS)

    A study of the technical and financial pre-feasibility is realized for the handling, conditioning and sale as fuel in cement industries of petroleum coke, that is produced in the project of extension and modernization of the refinery of RECOPE in Moin, Limon. Daily production has been of 570 metric tons. The market study has determined a demand of approximately 120 000 metric tons in the country and in the region. The total production of coke has been possible place it at national and regional level, due to lack of another producer. The coke is recommended to crush it to decrease the size of the particles for the conditioning, handling and to facilitate their manipulation. Conveyor belts are used for handling on the inside of the refinery. The coke is transported in trucks type tanker on the exterior of the refinery. The moisture content is reduced by dryer vibratory of fluidized bed to 5% of moisture to guarantee a product better quality. The product is stored under roof in ventilated facilities and with appropriate systems of security to minimize the risk of an accident. The fixed capital investment to develop the project has been of USD 3,1 millions and working capital of USD 14,4 millions. The financial evaluation is realized considering two financing models of 70% and without financing. The net present value (NPV) has been of USD -13,0 millions and the desirability index of -6,6 for the model with financing. The model without financing has obtained a NPV of USD -1,9 millions and a desirability index of -1,2. The financial profitability of the project has been very sensitive to the sales price of the coke, to the coke volume of production, to the growth percentage of the sale price and the cost of the raw material for the two models considered. The financial risk analysis is realized by the Monte Carlo method, whereupon is obtained a probability of approximately 34% in that the internal rate of return (IRR) has been higher than the cut rate and of 36% in that

  5. Methods and Production of Cementation Materials for Immobilisation into Waste Form. Research of Cementation Processes for Specific Liquid Radioactive Waste Streams of Radiochemical Plants

    International Nuclear Information System (INIS)

    In the near future Russian Federation is planning to use industrial cementation facilities at two radiochemical combines - PA 'Mayak' and Mountain Chemical Combine. Scope of the research within the IAEA CRP contact No. 14176 included the development of cementation processes for specfic liquid radioactive waste streams that are present in these enterprisers. The research on cementation of liquid waste from spent nuclear fuel reprocessing at PA 'Mayak' allowed obtaining experimental data characterizing the technological process and basic characteristics of the produced cement compounds (e.g. mechanical strength, water resistance, frost resistance, flowability, etc.) immobilizing different streams of waste (e.g. hydrated-salt sludges, filter material pulps, mixture of hydrated salt slurries and filter material pulps, tritium liquid waste). Determined optimum technological parameters will allow industrial scale production of cement compound with required quality and higher flowability that is necessary for providing uniform filling of compartments of storage facilities at these sites. The research has been also carried out for the development of cementation technology for immobilization of pulps from storage tanks of Mountain Chemical Combine radiochemical plant. Cementation of such pulps is a difficult technological task because pulps are of complex chemical composition (e.g. hydroxides of manganese, iron, nickel, etc., as well as silicon oxide) and a relatively high activity. The research of cementation process selection for these pulps included studies of the impact of sorbing additive type and content on cement compounds leachability, flowability, impact of cement compound age to its mechanical strength, heat generation of cement compounds and others. The research results obtained allowed testing of cementation facility with a pulse type mixer on the full-scale. Use of such mixer for pulp cementation makes possible to prepare a homogeneous cement compound with the

  6. Respiratory Health among Cement Workers in Ethiopia

    OpenAIRE

    Zeleke, Zeyede K.

    2011-01-01

    Background: Little is known on dust exposure and respiratory health among cement cleaners. There are only a few follow-up studies on respiratory health among cement factory workers and also studies on acute effects of cement dust exposure are limited in numbers. Objective: This study aimed at assessing cement dust exposure and adverse respiratory health effects among Ethiopian cement production workers, with particular focus on cement cleaners. Method: The first paper was...

  7. Biological effects: asbestos-cement manufacturing.

    Science.gov (United States)

    Weill, H

    1994-08-01

    Fourteen cohorts of asbestos-cement workers have been studied. These studies have demonstrated exposure-response relationships for lung cancer, mesothelioma and asbestosis. For lung cancer, relatively consistent results have been observed, with risk two-fold or less in 13 of the 14 cohorts. Among New Orleans workers, excess risk was restricted to those with X-ray evidence of asbestosis. Workers employed at least 21 years but without X-ray abnormalities, experienced no elevated risk, while those with small opacities (1/0 or higher) had substantially elevated risk (SMR > 400). Exposures in these two groups had been similar. These results suggest that asbestosis may be a necessary precursor for asbestos-induced lung cancer; if so, then the no-threshold model for lung cancer risk is inappropriate since there is general agreement that very low exposures will not result in radiologically detectable lung fibrosis. Further data on this potential link are needed. As in other industries, mesothelioma risk was strongly related to amphibole exposure, especially to crocidolite in asbestos-cement pipe manufacture. A cluster of cases has recently been reported in a family amosite-cement business. Among New Orleans workers, risk of asbestosis was related to cumulative exposure but there was little evidence of risk below 30 f ml-1-years. Progression of asbestosis in these workers was slow, related to past cumulative exposure and not related to lung function decline. Asbestosis risk is therefore not likely to develop in workers under current controlled exposure conditions. PMID:7978975

  8. Leaching tests of cemented organic radioactive waste

    International Nuclear Information System (INIS)

    The use of radioisotopes in research, medical and industrial activities generates organic liquid radioactive wastes. At Centro de Desenvolvimento da Tecnologia Nuclear (CDTN) are produced organic liquid wastes from different sources, one of these are the solvent extraction activities, whose the waste volume is the largest one. Therefore a research was carried out to treat them. Several techniques to treat organic liquid radioactive wastes have been evaluated, among them incineration, oxidation processes, alkaline hydrolysis, distillation, absorption and cementation. Laboratory experiments were accomplished to establish the most adequate process in order to obtain qualified products for storage and disposal. Absorption followed by cementation was the procedure used in this study, i.e. absorbent substances were added to the organic liquid wastes before mixing with the cement. Initially were defined the absorbers, and evaluated the formulation in relation to the compressive strength of its products. Bentonite from different suppliers (B and G) and vermiculite in two granulometries (M - medium and F - small) were tested. In order to assess the product quality the specimens were submitted to the leaching test according the Standard ISO 6961 and its results were evaluated. Then they were compared with the values established by Standard CNEN NN 6.09 Acceptance criteria for waste products to be disposed, to verify if they meet the requirements for safely storage and disposal. Through this study the best formulations to treat the organic wastes were established. (author)

  9. Photon attenuation characteristics of barium enriched cement

    International Nuclear Information System (INIS)

    Nuclear radiations are widely used in several applications of nuclear sciences, medicine and industry. In the design and construction of installations housing high intensity radioactive sources and other radiation generating equipment, a variety of shielding materials are used to minimise the exposure to the individuals. Among the materials used, lead is best known for radiation shielding due to its high density and atomic number. However, in construction of radiation facilities, lead in the form of bricks or slabs cannot be substituted for cement as building material. As an alternative, barium enriched cement, which apart from better compressive strength, smoother surface finish and high abrasive resistance, offers adequate shielding to gamma radiations. In the present work, attenuation properties of commercial as well as barium enriched cements have been studied and compared with that of lead for photons of 662 and 1250 keV emitted from 137Cs and 60Co, respectively. Although photon attenuation data can be obtained by mixture rule theoretically, it is necessary to determine this data experimentally before use

  10. Random ionic mobility on blended cements exposed to aggressive environments

    International Nuclear Information System (INIS)

    It is known that the partial replacement of cement by pozzolanic admixtures generally leads to modifications in the diffusion rates of harmful ions. Recent research has centred on obtaining new pozzolanic materials from industrial waste and industrial by-products and on the way that such products can influence the performance of blended cements. This paper reports the behaviour of cements blended with calcined paper sludge (CPS) admixtures under exposure to two different field conditions: sea water and cyclic changes in temperature and humidity. Cement mortars were prepared with 0% and 10% paper sludge calcined at 700 deg. C. The penetration of ions within the microstructure of cement matrices was studied using X-ray diffraction (XRD) and scanning electron microscopy equipped with an energy dispersive X-ray analyser (SEM/EDX) analytical techniques. The results show that ionic mobility varies substantially according to the type of exposure and the presence of the calcined paper sludge. The incorporation of 10% CPS is shown to assist the retention and diffusion of the ions.

  11. Random ionic mobility on blended cements exposed to aggressive environments

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Rosario, E-mail: rosario.garcia@uam.es [Departamento de Geologia y Geoquimica, Facultad de Ciencias, Universidad Autonoma, 28049 Madrid (Spain); Rubio, Virginia [Departamento de Geografia, Facultad de Filosofia y Letras, Universidad Autonoma, 28049 Madrid (Spain); Vegas, Inigo [Labein-Tecnalia, 48160 Derio, Vizcaya (Spain); Frias, Moises [Instituto Eduardo Torroja, CSIC, c/ Serrano Galvache, 4, 28033 Madrid (Spain)

    2009-09-15

    It is known that the partial replacement of cement by pozzolanic admixtures generally leads to modifications in the diffusion rates of harmful ions. Recent research has centred on obtaining new pozzolanic materials from industrial waste and industrial by-products and on the way that such products can influence the performance of blended cements. This paper reports the behaviour of cements blended with calcined paper sludge (CPS) admixtures under exposure to two different field conditions: sea water and cyclic changes in temperature and humidity. Cement mortars were prepared with 0% and 10% paper sludge calcined at 700 deg. C. The penetration of ions within the microstructure of cement matrices was studied using X-ray diffraction (XRD) and scanning electron microscopy equipped with an energy dispersive X-ray analyser (SEM/EDX) analytical techniques. The results show that ionic mobility varies substantially according to the type of exposure and the presence of the calcined paper sludge. The incorporation of 10% CPS is shown to assist the retention and diffusion of the ions.

  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. 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

  14. Nuevas tendencias en la investigación en salud mental.

    OpenAIRE

    GHMM ten Horn

    2004-01-01

    Debido a que el modelo de atención en salud mental ha cambiado desde una orientación hospitalaria a una comunitaria, la orientación de los investigadores ha cambiado también. La nueva tendencia es investigar prestando mayor atención a la prevención, la cronicidad, la colaboración entre salud mental y atención primaria, y el entorno de los sujetos en estudio.

  15. A consistent thermodynamic database for cement materials

    International Nuclear Information System (INIS)

    In the context of waste confinement and, more specifically, waste from the nuclear industry, concrete is used both as a confinement and as a building material. Alteration processes in contact with clayey formations are also of interest in the context of deep disposal. The present work aims to propose a collection of thermodynamic properties for geochemical calculation in cementitious media. This selection is extended to zeolites and clay minerals in the context of cement/clay interactions. Finally, because temperature is of importance in such contexts, the temperature dependency of the thermodynamic functions is also considered here. Uncertainties remain concerning especially katoite, and some low temperature zeolites like phillipsite, chabazite or gismondine

  16. Tendencia de los consumos de alimentos en Colombia

    Directory of Open Access Journals (Sweden)

    Kalmanovitz Salomón

    1980-12-01

    Full Text Available En un tipo de economía como la colombiana, caracterizada por salarios que tienen muy poca ligazón con la productividad social del trabajo, estos son por lo general muy bajos y una parte de ellos, que llega a ser más de la mitad, se dedica a la adquisición de alimentos. Mientras el salario mínimo en Colombia era en enero de 1979 de US$ 3.10 diarios, en Estados Unidos era de US$ 3.75 la hora, al tiempo que la jornada de trabajo acá era un 20% más larga (48 horas a la semana contra 40 , lo que representa una diferencia abismal de 12 veces. Las diferencias de productividad industrial en 1974 eran de sólo 4 veces en términos de valor agregado por trabajador o sea que un capitalista operando en el país estrujaba 3 veces más trabajo sobrante a cada obrero que el correspondiente a un empresario yanki.

  17. Colorectal cancer and non-malignant respiratory disease in asbestos cement and cement workers. Studies on mortality, cancer morbidity, and radiographical changes in lung parenchyma and pleura

    Energy Technology Data Exchange (ETDEWEB)

    Jacobsson, K.

    1993-09-01

    Radiologically visible parenchymal changes (small opacities >= 1/0;ILO 1980 classification) were present in 20% of a sample of workers (N=174), employed for 20 years (median) in an asbestos cement plant. Exposure-response relationships were found, after controlling for age and smoking habits. In a sample of asbestos cement workers with symptoms and signs suggestive of pulmonary disease (N=33), increased lung density measured by x-ray computed tomography, and reduced static lung volumes and lung compliance was found. In a cohort of asbestos cement workers (N=1.929) with an estimated median exposure of 1.2 fibres/ml, the mortality from non-malignant respiratory disease was increased in comparison to a regional reference cohort (N=1.233). A two-to three-fold increase of non-malignant respiratory mortality was noted among workers employed for more than a decade in the asbestos cement plant, compared to cement workers (N=1.526), who in their turn did not experience and increased risk compared to the general population. In the cohorts of asbestos cement and cement workers, there was a tow-to three-fold increased incidence of cancer in the right part of the colon, compared to the general population as well as to external reference cohorts of other industrial workers (N=3.965) and fishermen (N=8.092). A causal relation with the exposure to mineral dust and fibres was supported by the findings of higher risk estimated in subgroups with high cumulated asbestos doses or longer duration of cement work. The incidence of cancer in the left part of the colon was not increased. Morbidity data, but not mortality data, disclosed the subsite-specific risk pattern. Both asbestos cement workers and cement workers has an increased incidence of rectal cancer, compared with the general population, and with the fishermen. The risk was, however, of the same magnitude among the other industrial workers. 181 refs.

  18. The Effect of Cement Dust on the Lung Function in a Cement Factory, Iran

    Directory of Open Access Journals (Sweden)

    Farhad Ferasati

    2010-07-01

    Full Text Available The present study aimed at assessing cement dust exposure and its relationship to lung function at a Portland cement factory in Ilam, Iran. Lung function tests were carried out on 112 workers at the cement factory in 2008-09. Simultaneously 85 non exposed workers were used as control. Lung function tests were performed for all subjects. Additionally, total dust level was determined by the gravimetric method. Moreover, X-ray diffraction (XRD technique was performed to determine the SiO2 contents of the bulk samples. The arithmetic means (AM of personal total dust were higher in the crusher (27.49 mg/m3, packing (16.90 mg/m3, kiln (15.60 mg/m3, cement mill (13.07 mg/m3, raw mill (10.31 mg /m3 than in the maintenance (3.14 mg /m3, and administration (1.55 mg/m3. The geometrical mean (GM concentration was 12.12 mg/m3, which were considerably higher than occupational exposure limit (OEL of the American Conference of Governmental Industrial Hygienists (ACGIH, which is 10 mg/m3. Based on the results, the probability of the long-term mean exposure exceeding to the OEL of 10 mg/m3 for total dust were higher in the kiln (100%, packing (100%, cement mill (90%, crusher (73%, raw mill (60% than in the maintenance (0%, and administration (2.3%. Ventiliatory function evaluation, as measured by the function parameters, showed that 35.7% of the exposed workers had abnormality in lung function compared with 5.7% of those unexposed. Statistical analysis of the data indicated that exposed workers compared to the unexposed groups showed significant reductions in Forced Expiratory Volume in one second percent (FEV1, Forced Vital Capacity (FVC, and FEV1/FVC (p< 0.05.

  19. Enhancement of cemented waste forms by supercritical CO{sub 2} carbonation of standard portland cements

    Energy Technology Data Exchange (ETDEWEB)

    Rubin, J.B.; Carey, J.; Taylor, C.M.V.

    1997-08-01

    We are conducting experiments on an innovative transformation concept, using a traditional immobilization technique, that may significantly reduce the volume of hazardous or radioactive waste requiring transport and long-term storage. The standard practice for the stabilization of radioactive salts and residues is to mix them with cements, which may include additives to enhance immobilization. Many of these wastes do not qualify for underground disposition, however, because they do not meet disposal requirements for free liquids, decay heat, head-space gas analysis, and/or leachability. The treatment method alters the bulk properties of a cemented waste form by greatly accelerating the natural cement-aging reactions, producing a chemically stable form having reduced free liquids, as well as reduced porosity, permeability and pH. These structural and chemical changes should allow for greater actinide loading, as well as the reduced mobility of the anions, cations, and radionuclides in aboveground and underground repositories. Simultaneously, the treatment process removes a majority of the hydrogenous material from the cement. The treatment method allows for on-line process monitoring of leachates and can be transported into the field. We will describe the general features of supercritical fluids, as well as the application of these fluids to the treatment of solid and semi-solid waste forms. some of the issues concerning the economic feasibility of industrial scale-up will be addressed, with particular attention to the engineering requirements for the establishment of on-site processing facilities. Finally, the initial results of physical property measurements made on portland cements before and after supercritical fluid processing will be presented.

  20. Enhancement of cemented waste forms by supercritical CO2 carbonation of standard portland cements

    International Nuclear Information System (INIS)

    We are conducting experiments on an innovative transformation concept, using a traditional immobilization technique, that may significantly reduce the volume of hazardous or radioactive waste requiring transport and long-term storage. The standard practice for the stabilization of radioactive salts and residues is to mix them with cements, which may include additives to enhance immobilization. Many of these wastes do not qualify for underground disposition, however, because they do not meet disposal requirements for free liquids, decay heat, head-space gas analysis, and/or leachability. The treatment method alters the bulk properties of a cemented waste form by greatly accelerating the natural cement-aging reactions, producing a chemically stable form having reduced free liquids, as well as reduced porosity, permeability and pH. These structural and chemical changes should allow for greater actinide loading, as well as the reduced mobility of the anions, cations, and radionuclides in aboveground and underground repositories. Simultaneously, the treatment process removes a majority of the hydrogenous material from the cement. The treatment method allows for on-line process monitoring of leachates and can be transported into the field. We will describe the general features of supercritical fluids, as well as the application of these fluids to the treatment of solid and semi-solid waste forms. some of the issues concerning the economic feasibility of industrial scale-up will be addressed, with particular attention to the engineering requirements for the establishment of on-site processing facilities. Finally, the initial results of physical property measurements made on portland cements before and after supercritical fluid processing will be presented

  1. Magnesium oxychloride cement concrete

    Indian Academy of Sciences (India)

    A K Misra; Renu Mathur

    2007-06-01

    The scope of magnesium oxychloride (MOC) cement in concrete works has been evaluated. MOC cement concrete compositions of varying strengths having good placing and finishing characteristics were prepared and investigated for their compressive and flexural strengths, -values, abrasion resistance etc. The durability of MOC concrete compositions against extreme environmental conditions viz. heating–cooling, freezing–thawing, wetting–drying and penetration and deposition of salts etc were investigated. The results reveal that MOC concrete has high compressive strength associated with high flexural strength and the ratio of compressive to flexural strength varies between 6 and 8. The elastic moduli of the compositions studied are found to be 23–85 GPa and the abrasion losses between 0.11 and 0.20%. While alternate heating–cooling cycles have no adverse effect on MOC concrete, it can be made durable against freezing–thawing and the excessive exposure to water and salt attack by replacing 10% magnesium chloride solution by magnesium sulphate solution of the same concentration.

  2. Sustainable Nanopozzolan Modified Cement: Characterizations and Morphology of Calcium Silicate Hydrate during Hydration

    Directory of Open Access Journals (Sweden)

    N. Mohamed Sutan

    2015-01-01

    Full Text Available There are environmental and sustainable benefits of partially replacing cement with industrial by-products or synthetic materials in cement based products. Since microstructural behaviours of cement based products are the crucial parameters that govern their sustainability and durability, this study investigates the microstructural comparison between two different types of cement replacements as nanopozzolan modified cement (NPMC in cement based product by focusing on the evidence of pozzolanic reactivity in corroboration with physical and mechanical properties. Characterization and morphology techniques using X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR, energy-dispersive X-ray spectroscopy (EDS, and scanning electron microscopy (SEM were carried out to assess the pozzolanic reactivity of cement paste modified with the combination of nano- and micro silica as NPMC in comparison to unmodified cement paste (UCP of 0.5 water to cement ratio (w/c. Results were then substantiated with compressive strength (CS results as mechanical property. Results of this study showed clear evidence of pozzolanicity for all samples with varying reactivity with NPMC being the most reactive.

  3. 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.

  4. Evaluation of oxidative stress and DNA damage in cement and tannery workers in Egypt.

    Science.gov (United States)

    Elhosary, Naema; Maklad, Aisha; Soliman, Eman; El-Ashmawy, Nahla; Oreby, Merfat

    2014-04-01

    In Egypt, workers have potentially high exposure levels to chromium (VI) in the cement production and construction industry and to chromium (III) in the leather tanning industry. This study aimed to evaluate the effect of chromium exposure on lipoperoxidation, thiol antioxidants and DNA in cement and tannery workers. This study was conducted on 65 adult male volunteers. These subjects were divided into three groups: Group I (control group); 23 normal healthy volunteers, Group II; 22 cement workers and Group III; 20 tannery workers. All participants were subjected to thorough history, clinical examination and laboratory determination of total blood and urinary chromium, plasma malondialdehyde and total thiol in plasma and assessment of oxidative DNA damage through p53 overexpression. About one third of cement and tannery workers had severe skin and chest manifestations and severe nasal manifestations were observed in 22.7% and 20% of cement and tannery workers, respectively. The blood and urinary Cr and plasma malondialdehyde levels of cement and tannery were significantly higher than control group. Additionally, there was a significant increase of total thiol in control group compared to exposed groups. About half of cement and one third of tannery groups expressed high grade of p53 expression. The blood chromium revealed significant negative correlation with thiol, but, positive correlation with malondialdehyde and p53 expression. Cement and tannery workers should be subjected to frequent clinical examination and blood or urine chromium analysis level to keep guard against its toxic consequences. PMID:24617565

  5. Thermodynamic and exergoeconomic analysis of a cement plant: Part I – Methodology

    International Nuclear Information System (INIS)

    Highlights: • Energy, exergy and exergoeconomic analysis of a complete cement plant have been investigated. • The first and second law efficiencies based on the energy and exergy analysis are defined for the entire cement plant. • The specific energy consumption of the whole sections of the cement plant have been analyzed. • The specific manufacturing costs of farine, clinker and cement have been determined by the cost analysis. - Abstract: The energy, exergy and exergoeconomic analysis of a cement factory has been studied within two parts. This paper is the first part of the study which includes the thermodynamic and exergoeconomic methodology and formulations developed for such a comprehensive and detailed analysis. The second part of this study is about the application of the developed formulation which considers an actual cement plant located in Gaziantep, Turkey. The energy consumption by the cement industry is about 5% of the total global industrial energy consumption. It is also one of the world’s largest industrial sources of CO2 emissions. In this paper, a cement plant is considered with all main manufacturing units. Mass, energy, and exergy balances are applied to each system. The first and second law efficiencies based on the energy and exergy analysis and performance assessment parameters are defined for the entire cement plant. The formulations for the cost of products, and cost formation and allocation within the system are developed based on exergoeconomic analysis. In order to obtain the optimal marketing price of cement and to decrease specific energy consumption of the whole plant, the cost analysis formulated here have substantial importance

  6. Radionuclide and metal sorption on cement and concrete

    CERN Document Server

    Ochs, Michael; Wang, Lian

    2016-01-01

    Cementitious materials are being widely used as solidification/stabilisation and barrier materials for a variety of chemical and radioactive wastes, primarily due to their favourable retention properties for metals, radionuclides and other contaminants. The retention properties result from various mineral phases in hydrated cement that possess a high density and diversity of reactive sites for the fixation of contaminants through a variety of sorption and incorporation reactions. This book presents a state of the art review and critical evaluation of the type and magnitude of the various sorption and incorporation processes in hydrated cement systems for twenty-five elements relevant for a broad range of radioactive and industrial wastes. Effects of cement evolution or ageing on sorption/incorporation processes are explicitly evaluated and quantified. While the immobilisation of contaminants by mixing-in during hydration is not explicitly addressed, the underlying chemical processes are similar. A quantitativ...

  7. 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.

  8. Radiometric systems for monitoring material flow through cement works furnaces

    International Nuclear Information System (INIS)

    The measuring system uses the principle of monitoring the attenuation of a gamma-ray beam following passage through matter. The transported material travels in the space between the radiation source and the detector. Radiometric material flow monitoring was industrially used in cement works for monitoring the flow of material through an exchanger shaft and two exchangers on the Portland cement production line, and for measuring the thickness of deposits on the cyclone exchanger lining on the white cement production line. 137Cs sources of activities in the range of 6.65 to 26.6 GBq and a 60Co source of an activity of 16.6 GBq were used. The radiation was detected using Geiger-Mueller counters. The measuring systems thus implemented feature long-term reliability, minimal failure rate and minimal requirements for operation and maintenance. (J.C.)

  9. Energy efficiency enhancement in cement factories using expert system

    International Nuclear Information System (INIS)

    Full text : In this paper, expert system for energy efficiency in cement industry is presented. Due to the fact that cement manufacturing project in these factories are similar, so in main parts knowing the consumption origins and save potential and existing approaches can be similar. In this method, via expert system software of prolog AH types of energy consumption and investment costs are listed in which method of best first search and innovative search have been used and by forming knowledge base, targeting to get best approaches is presented. The obtained results, regarding the executed limits, will be displayed in the output of program and this program can be given the best decision about energy management in cement factories

  10. Utilization of gold tailings as an additive in Portland cement.

    Science.gov (United States)

    Celik, Ozlem; Elbeyli, Iffet Yakar; Piskin, Sabriye

    2006-06-01

    Mine tailings are formed as an industrial waste during coal and ore mining and processing. In the investigated process, following the extraction of gold from the ore, the remaining tailings are subjected to a two-stage chemical treatment in order to destroy the free cyanide and to stabilize and coagulate heavy metals prior to discharge into the tailings pond. The aim of this study was the investigation of the feasibility of utilization of the tailings as an additive material in Portland cement production. For this purpose, the effects of the tailings on the compressive strength properties of the ordinary Portland cement were investigated. Chemical and physical properties, mineralogical composition, particle size distribution and microstructure of the tailings were determined by Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), particle size analyzer (Mastersizer) and scanning electron microscope (SEM). Following the characterization of the tailings, cement mortars were prepared by intergrinding Portland cement with dried tailings. Composition of the cement clinkers were adjusted to contain 5, 15, 25% (wt/wt) dried tailings and also silica fume and fly ash samples (C and F type) were added to clinker in different ratios. The mortars produced with different amounts of tailings, silica fume, fly ashes and also mixtures of them were tested for compressive strength values after 2, 7, 28 and 56 days according to the European Standard (EN 196-1). The results indicated that gold tailings up to 25% in clinker could be beneficially used as an additive in Portland cement production. It is suggested that the gold tailings used in the cement are blended with silica fume and C-type fly ash to obtain higher compressive strength values. PMID:16784164

  11. Cements in Radioactive Waste Disposal

    International Nuclear Information System (INIS)

    The use of cement and concrete to immobilise radioactive waste is complicated by the wide- ranging nature of inorganic cementing agents available as well as the range of service environments in which cement is used and the different functions expected of cement. For example, Portland cement based concretes are widely used as structural materials for construction of vaults and tunnels. These constructions may experience a long pre-closure performance lifetime during which they are required to protect against collapse and ingress of water: strength and impermeability are key desirable characteristics. On the other hand, cement and concrete may be used to form backfills, ranging in permeability. Permeable formulations allow gas readily to escape, while impermeable barriers retard radionuclide transport and reduce access of ground water to the waste. A key feature of cements is that, while fresh, they pass through a fluid phase and can be formed into any shape desired or used to infiltrate other materials thereby enclosing them into a sealed matrix. Thereafter, setting and hardening is automatic and irreversible. Where concrete is used to form structural elements, it is also natural to use cement in other applications as it minimises potential for materials incompatibility. Thus cement- mainly Portland cement- has been widely used as an encapsulant for storage, transport and as a radiation shield for active wastes. Also, to form and stabilise structures such as vaults and silos. Relative to other potential matrices, cement also has a chemical immobilisation potential, reacting with and binding with many radionuclides. The chemical potential of cements is essentially sacrificial, thus limiting their performance lifetime. However performance may also be required in the civil engineering sense, where strength is important, so many factors, including a geochemical description of service conditions, may require to be assessed in order to predict performance lifetime. The

  12. Cement/slag chemistry studies

    International Nuclear Information System (INIS)

    The performance of cement-based matrices intended for radwaste immobilization is assessed. The long-term performance of the matrix is characterized by thermodynamic evaluation of experimental data. The results are presented in a general form, amenable to a range of specific formulations. The interaction of specific radwaste components with cements has been studied, using Iodine as an example. It occurs as both I- and IO3- species, but these differ sharply in sorption characteristics. The effect of ionizing radiation of the pH and Eh of cement matrices is reported. (author)

  13. The polymer cement of sulfur as an alternative for the recycling of phosphogypsum. Corrosion testing of cements enriched with phosphogypsum; El cemento polimerico de azufre como alternative para el reciclado de fosfoyesos. Pruebas de corrosion de cementos enriquecidos con fosfoyesos

    Energy Technology Data Exchange (ETDEWEB)

    Gasco, C.; Lopez, F. A.; Navarro, N.; Sanchez, M.; Sanz, B.; Ballesteros, O.; Higueras, E.; Roman, C. P.

    2011-07-01

    The possibility of the use of cement for the recycling of materials is seen today as sustainable solution of the fertilizer industry for production of matches (NORM). In this paper presents some results of corrosion tests performed on these cements modified using buffer solutions of different pH. The analytical determinations in these matrices are new challenges. (Author)

  14. Exergy analyses in cement production applying waste fuel and mineralizer

    International Nuclear Information System (INIS)

    Highlights: • The exergy destroyed from calciner and rotary kiln correspond 47% and 30%. • Mineralizer saves energy. • Waste fuel provides 12% of energy demand. - Abstract: The cement industry is an energy-intensive industry and emits large quantities of carbon dioxide, so waste fuels could usefully substitute part of the fossil fuels. They can also help resolve air pollution problems associated with the use of fossil fuels. Other wastes have properties of reducing the thermal energy consumption of clinker production. They are named mineralizers. Then the application of both in the cement industry contributes to the reduction of environmental liabilities and provides lower cost of acquisition of fossil fuels. The aim of the present study is confirm the advantages of the application of waste SPL (spent pot lining) as a mineralizer in clinker production from an exergetic viewpoint

  15. Leaching Study in Immobilization of Cesium and Cobalt Radionuclides In Fly Ash- Zeolite Cement

    International Nuclear Information System (INIS)

    Fly ash-zeolite cement was synthesized from industrial by-product fly ash obtained from the thermal electric power station. The synthesis process is based on the hydrothermal-calcination-route of the fly ash. The microstructure of fly ash-zeolite cement was characterized by X-ray diffraction, FT infrared spectroscopy and surface area (F-N2). The efficiency of innovative matrices for immobilizing cesium and cobalt radionuclides is presented in this work. The aim of the present study is to investigate the possibility of solidifying 137Cs and 60Co radionuclides in synthetic fly ash zeolite cement. Leaching behavior of the radionuclides have been studied. The leachability index measured indicated that fly ash zeolite cement matrix can be utilized as an efficient material for immobilizing cesium and cobalt radionuclides than portland cement.

  16. Optimization of fly ash as sand replacement materials (SRM) in cement composites containing coconut fiber

    Science.gov (United States)

    Nadzri, N. I. M.; Jamaludin, S. B.; Mazlee, M. N.; Jamal, Z. A. Z.

    2016-07-01

    The need of utilizing industrial and agricultural wastes is very important to maintain sustainability. These wastes are often incorporated with cement composites to improve performances in term of physical and mechanical properties. This study presents the results of the investigation of the response of cement composites containing coconut fiber as reinforcement and fly ash use as substitution of sand at different hardening days. Hardening periods of time (7, 14 and 28 days) were selected to study the properties of cement composites. Optimization result showed that 20 wt. % of fly ash (FA) is a suitable material for sand replacement (SRM). Meanwhile 14 days of hardening period gave highest compressive strength (70.12 MPa) from the cement composite containing 9 wt. % of coconut fiber and fly ash. This strength was comparable with the cement without coconut fiber (74.19 MPa) after 28 days of curing.

  17. 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.

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

    NARCIS (Netherlands)

    Kempl, J.; Copuroglu, O.

    2015-01-01

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

  19. Cementing porcelain-fused-to-metal crowns.

    Science.gov (United States)

    Vadachkoria, D

    2009-12-01

    The clinical success of fixed prosthodontic restorations can be complex and involve multifaceted procedures. Preparation design, oral hygiene/micro flora, mechanical forces, and restorative materials are only a few of the factors which contribute to overall success. One key factor to success is choosing the proper cement. Popular use of cements for PFM crowns has shifted from zinc phosphate and glass ionomer cements to resin-reinforced glass ionomer, or RRGI, cements. This change has been rapid and profound. Dental cements have always been less than ideal materials, but this is shift to the relatively new RRGI category justified. Resin-reinforced glass ionomer (RRGI) cements appear to be better than zinc phosphate and glass ionomer cements when placing porcelain-to-metal crowns. RRGI cements, such as RelyX Luting, Fuji Plus and Vitremer Luting Cement, satisfy more of the ideal characteristics of PFM cementation than any other previous cement. Expansion of all three cements has not caused any apparent problems with the cements when used with PFM or metal crowns, but these cements, however, should be avoided when cementing all-ceramic crowns. PMID:20090144

  20. Assessment of non-destructive testing of well casing,, cement and cement bond in high temperature wells

    Energy Technology Data Exchange (ETDEWEB)

    Knutson, C K; Boardman, C R

    1979-01-01

    Because of the difficulty in bringing geothermal well blowouts under control, any indication of a casing/cement problem should be expeditiously evaluated and solved. There are currently no high temperature cement bond and casing integrity logging systems for geothermal wells with maximum temperatures in excess of 500/sup 0/F. The market is currently insufficient to warrannt the private investment necessary to develop tools and cables capable of withstanding high temperatures. It is concluded that a DOE-funded development program is required to assure that diagnostic tools are available in the interim until geothermal resource development activities are of sufficient magnitude to support developmental work on high temperature casing/cement logging capabilities by industry. This program should be similar to and complement the current DOE program for development of reservoir evaluation logging capabilities for hot wells. The appendices contain annotated bibliographies on the following: high temperature logging in general, cement integrity testing, cosing integrity testing, casing and cement failures, and special and protective treatment techniques. Also included are composite listing of references in alphabetical order by senior author.

  1. Sliding wear of cemented carbides

    International Nuclear Information System (INIS)

    Cemented carbides are known to be very hard and wear resistant and are therefor often used in applications involving surface damage and wear. The wear rate of cemented carbides is often measured in abrasion. In such tests it has been shown that the wear rate is inversely dependent on the material hardness. The sliding wear is even more of a surface phenomenon than a abrasion, making it difficult to predict friction and wear from bulk properties. This paper concentrates on the sliding wear of cemented carbides and elucidates some wear mechanisms. It is especially shown that a fragmenting wear mechanism of WC is very important for the description of wear of cemented carbides. (author)

  2. Calcium Aluminate Cement Hydration Model

    Directory of Open Access Journals (Sweden)

    Matusinović, T.

    2011-01-01

    Full Text Available Calcium aluminate cement (AC is a very versatile special cement used for specific applications. As the hydration of AC is highly temperature dependent, yielding structurally different hydration products that continuously alter material properties, a good knowledge of thermal properties at early stages of hydration is essential. The kinetics of AC hydration is a complex process and the use of single mechanisms models cannot describe the rate of hydration during the whole stage.This paper examines the influence of temperature (ϑ=5–20 °C and water-to-cement mass ratio (mH /mAC = 0.4; 0.5 and 1.0 on hydration of commercial iron-rich AC ISTRA 40 (producer: Istra Cement, Pula, Croatia, which is a part of CALUCEM group, Figs 1–3. The flow rate of heat generation of cement pastes as a result of the hydration reactions was measured with differential microcalorimeter. Chemically bonded water in the hydrated cement samples was determined by thermo-gravimetry.Far less heat is liberated when cement and water come in contact for the first time, Fig. 1, than in the case for portland cement (PC. Higher water-to-cement ratio increases the heat evolved at later ages (Fig. 3 due to higher quantity of water available for hydration. A significant effect of the water-to-cement ratio on the hydration rate and hydration degree showed the importance of water as being the limiting reactant that slows down the reaction early. A simplified stoichiometric model of early age AC hydration (eq. (8 based on reaction schemes of principal minerals, nominally CA, C12A7 and C4AF (Table 1, was employed. Hydration kinetics after the induction period (ϑ < 20 °C had been successfully described (Fig. 4 and Table 2 by a proposed model (eq. (23 which simultaneously comprised three main mechanisms: nucleation and growth, interaction at phase boundary, and mass transfer. In the proposed kinetic model the nucleation and growth is proportional to the amount of reacted minerals (eq

  3. Tendencia de I+D+i en Biomecánica aplicada al deporte

    OpenAIRE

    Ferro Sanchez, Amelia

    2012-01-01

    Análisis de la investigación en el ámbito de la Biomecánica aplicada al deporte. La tendencia de los proyectos en I+D+i de la Biomecánica del Deporte ha cambiado notablemente en las dos últimas décadas. Los investigadores han pasado de aplicar la biomecánica al alto rendimiento deportivo a tratar temas transversales, relacionados en muchos casos con la salud, fisiología, rehabilitación, el control motor, la gestión y, entre otros, el diseño de equipamiento e instalaciones.

  4. Evolución y tendencias en la interacción persona-ordenador

    OpenAIRE

    Ribera-Turró, Mireia

    2005-01-01

    La autora resume en este artículo los diversos hitos en la historia de la interacción persona-ordenador, desde sus inicios a la etapa actual, en base a tres factores: la creatividad humana, la evolución de a tecnología y el uso de los ordenadores. En la etapa actual (a partir de 1989) el artículo analiza la influencia del entorno www y de la computación ubicua, nuevo paradigma computacional de gran impacto en la interacción persona¿ordenador. Finalmente presenta algunas tendencias que empieza...

  5. Algunas tendencias jurídicas de la globalización

    OpenAIRE

    De Miguel Asensio, Pedro Alberto

    2003-01-01

    La globalización se halla asociada a nuevas tendencias jurídicas en la ordenación de las actividades de sus actores, muy especialmente las empresas transnacionales, pero también el resto de las empresas y los particulares, así como de las relaciones de esos actores con los Estados. Objeto de especial atención son: el progresivo desarrollo de nuevos ámbitos de elaboración de normas, la creciente competencia de localización entre ordenamientos y el papel que desempeñan las organizadas privadas ...

  6. Tendencias y pronósticos de las infecciones nosocomiales en la provincia de Cienfuegos

    OpenAIRE

    Marta Luján Hernández

    2002-01-01

    Se realizó un estudio descriptivo retrospectivo sobre el comportamiento de las infecciones nosocomiales en la provincia de Cienfuegos durante el período de 1989-1998 para analizar las tendencias y elaborar pronósticos para los años 1999, 2000 y 2001. El dato primario se tomó del registro de información de las infecciones intrahospitalarias del Departamento de Estadísticas del Centro Provincial de Higiene y Epidemiología, de donde se extrajeron los siguientes datos: total de egresos por servic...

  7. Tendencia temporal de la mortalidad por armas de fuego en Argentina, 1980-2012

    OpenAIRE

    Hugo Spinelli; Adrián Santoro; Carlos Guevel; Marcio Alazraqui

    2015-01-01

    Este trabajo analiza el impacto de las armas de fuego en la mortalidad entre los años 1980-2012 en Argentina. Para ello se realiza un estudio epidemiológico descriptivo de la tendencia temporal, a través de las siguientes variables: sexo, grupos de edad, intencionalidad y jurisdicción. Los datos fueron obtenidos en la Dirección de Estadísticas e Información en Salud del Ministerio de Salud de la Nación. Se encontraron 87.671 muertes por armas de fuego. Los varones representaron el 85,7% y su ...

  8. Tendencias de mortalidad por traumatismos y envenenamientos en adolescentes: México, 1979-1997

    OpenAIRE

    Celis Alfredo; Gómez-Lomelí Zoila; Armas Jesús

    2003-01-01

    OBJETIVO: Describir las causas externas de la mortalidad por traumatismos y envenenamientos, así como la tendencia que estas causas han mostrado entre adolescentes en México, de 1979 a 1997. MATERIAL Y MÉTODOS: Para la realización de este estudio descriptivo de la mortalidad se utilizaron las bases de datos de mortalidad registrada en México de 1979 a 1997. Los datos son recabados, codificados y capturados por el Instituto Nacional de Estadística, Geografía e Informática, y se obtuvieron a tr...

  9. Estado y tendencia de la Administración de Proyectos en México

    OpenAIRE

    Vega Díaz, José Alberto

    2004-01-01

    El objetivo general de este estudio, es analizar el estado y las tendencias de la Administración de Proyectos en México e identificar el nivel de harmonización que hay entre la teoría y la puesta en práctica dentro de la industria mexicana. Esto ayudará a las partes interesadas a evaluar el estado del uso de la Administración de Proyectos dentro de su propia compañía en una base comparativa, reconocer y discutir las necesidades que tiene la práctica de la Administración d...

  10. Análisis de tendencias de heliofanía efectiva en Argentina

    OpenAIRE

    Hugo Grossi Gallegos; María Isabel Spreafichi

    2007-01-01

    Se presentan resultados del análisis estadístico de series temporales de promedios anuales de heliofanía efectiva (horas de brillo solar) registrados en estaciones de Argentina, que compensan la insuficiencia de datos de irradiación solar y permiten estudiar tendencias relacionadas con el Cambio Climático Global. Se aplicó un estudio previo de consistencia teniendo en cuenta el error de medición, con la aplicación del test de Mann-Kendall y se discuten los resultados obtenidos. Aparecen algun...

  11. La tendencia post gerencial en la determinación de la cultura organizacional del futuro

    OpenAIRE

    Lucas del Moral

    2000-01-01

    Este artículo nace de la necesidad de superar la falta de definición conceptual de lo que enfrentaremos en el futuro casi inmediato en el mundo de la administración de empresas y tuvo como finalidad la revisión bibliográfica desde el punto de vista del método de investigación documental-cualitativa, sobre una de las recientes tendencias de la Gerencia. Enfoca la atención sobre las tareas pasadas, actuales y futuras del Management y su influencia contemporánea en la determinación de la cultura...

  12. Geovisualización de la población: nuevas tendencias en la web social

    OpenAIRE

    Mateos, Pablo

    2013-01-01

    La visualización geográfica, o geovisualización, sitúa al espacio como eje central en la exploración del conocimiento sobre el mundo que nos rodea. En este artículo se resumen algunas de las nuevas tendencias en la geoweb y la geovisualización de información sociodemográfica. Se presentan una serie de aplicaciones desarrolladas en proyectos de investigación en University College London (UCL), Reino Unido. Dichos proyectos de geovisualización tienen como fin hacer accesibles al público en gene...

  13. La selección de personal en las organizaciones: externa vs. interna. Nuevas tendencias

    OpenAIRE

    Ruano Gómez, Jessica

    2014-01-01

    Con este trabajo se pretende, en primer lugar, ofrecer una panorámica de la selección de personal en las organizaciones, mostrando las diferentes vías para ello, con sus respectivas ventajas e inconvenientes; y por otro lado, se presentan las principales pruebas de criba presentes en un proceso de selección de personal, así como las nuevas tendencias que se están comenzando a aplicar en dicho proceso, todo ello complementado con documentos reales. Este trabajo tiene la intención de demostrar ...

  14. Tendencias financieras del Ayuntamiento de Córdoba en el periodo 1985-1994

    OpenAIRE

    Caridad y Ocerin, José María

    1996-01-01

    El municipio de Córdoba, de forma similar a muchos otros en Andalucía y en el resto de España, ha evolucionado en la última década, hacia una situación financiera caracterizada por un endeudamiento muy fuerte, y por un nivel de gasto corriente y de transferencias hacia empresas y fundaciones participadas, que siguen una tendencia creciente y acelerada, excediendo no sólo a la capacidad de recaudación sino también a la de endeudamiento. Se presentan aquí unos modelos de las t...

  15. Trabajo y salud en la industria maquiladora mexicana: una tendencia dominante en el neoliberalismo dominado

    OpenAIRE

    Villegas Jorge; Noriega Mariano; Martínez Susana; Martínez Sandra

    1997-01-01

    Se analizan las condiciones laborales y de salud de los trabajadores de la Industria Maquiladora de Exportación en México. Hace uso intensivo de la fuerza de trabajo mayoritariamente femenina,constituye la segunda fuente de divisas. Ilustra una tendencia dominante en el neoliberalimo respecto a condiciones de trabajo y salud, permite apreciar el impacto de la generalizada flexibilización laboral y del creciente cambio tecnológico. El panorama de los riesgos y exigencias es complejo. En la org...

  16. Assessment of Natural Radioactivity Levels of Cements and Cement Composites in the Slovak Republic

    OpenAIRE

    Adriana Eštoková; Lenka Palaščáková

    2013-01-01

    The radionuclide activities of 226Ra, 232Th and 40K and radiological parameters (radium equivalent activity, gamma and alpha indices, the absorbed gamma dose rate and external and internal hazard indices) of cements and cement composites commonly used in the Slovak Republic have been studied in this paper. The cement samples of 8 types of cements from Slovak cement plants and five types of composites made from cement type CEM I were analyzed in the experiment. The radionuclide activities in t...

  17. Assessment of the compatibility of wood and plastic with cement for their recycling in cement composites

    OpenAIRE

    Andrade, André De; Caldeira, Fernando

    2010-01-01

    The compatibility between maritime pine wood and cement, and between plastic (LDPE) and cement, was assessed for the recycling of wood and plastic in cement composites. Temperature vs. time profiles of cement setting were registered and compatibility indices were calculated. Results indicate that recycling of plastics in plastic-cement composites does not pose any questions regarding chemical compatibility. However, maritime pine hinders cement setting in some extent. So, in or...

  18. Defining criteria for cemented waste produced from legacy liquids

    International Nuclear Information System (INIS)

    Atomic Energy of Canada Limited (AECL) has several hundred cubic metres of legacy radioactive waste stored in underground tanks at the Chalk River Laboratories (CRL) site in Chalk River, Ontario. As part of a larger campaign to reduce its legacy liabilities, AECL intends to remove and immobilize this waste using a cementation system. AECL plans to hire an external contractor to design and operate a cementation skid to remove and condition the liquid wastes. Clear and measurable waste form criteria must be determined and provided to the contractor in order for the contractor to demonstrate that a safe and stable waste form has been produced. AECL has reviewed industry-standard test methods and best practices related to cementation of liquid nuclear wastes. Where suitable, these test methods and practices have been incorporated into Product Performance Criteria. An extensive test program has been performed to obtain cement formulations for the legacy wastes; the resulting sample cemented wastes have been tested and the results compared to the Product Performance Criteria. Modifications to the criteria have been made as required based on knowledge gained during this process. In addition, since no industry standards had previously been identified to measure homogeneity, 3 potential test methods have been identified. Regardless of the amount of testing performed and the stringency of the performance criteria, some risk remains that the waste will deteriorate over time. However, by performing a rigorous review of industry practice and an extensive series of tests under various conditions, AECL believes that it has addressed the risks in a reasonable and prudent manner and has selected the appropriate Product Performance Criteria to achieve a safe and stable waste product

  19. Impact of coal and rice husk ash on the quality and chemistry of cement clinker

    International Nuclear Information System (INIS)

    Utilization of rice husk as an alternative fuel for coal is of interest due to its availability in huge quantities in Pakistan and also because its combustion is environmental pollution friendly as it generates much less SOX due to its much lower sulphur content (0.1-0.3%) compared to sulphur content in coals, particularly indeginous coals ranging from 0.6-14.8%. The purpose of present study was to examine the impact of co-firing of rice husk and coal on the quality of cement clinker so as to substitute expensive imported coal with the abundantly available cheaper rice husk to reduce the cost of production of the cement. For this investigation raw feed mix (mixture of limestone, clay, bauxite and laterite in predetermined proportions) used for cement manufacture was mixed with predetermined varying proportions of coal ash and rice husk ash and placed inside a muffle furnace at 1200 degree C - 1500 degree C i-e the temperatures prevailing in the industrial cement kilns, for various periods of time to obtain cement clinker. The quality and chemistry of cement clinker thus produced in the laboratory was experimentally studied to ensure the quality of cement clinker that would be obtained by co-firing of rice husk and coal in different proportions in industrial cement kilns as the coal ash and rice husk ash produced during combustion will get mixed with cement clinker in industrial kilns. The results indicated that there was decrease in the Lime Saturation Factor, Free Lime and Tricalcium Silicate (C3S) content and increase in the Dicalcium Silicate (C2S) content by increasing the rice husk ash and decreasing the coal ash proportion in the clinker. (author)

  20. Hydration of blended cement pastes containing waste ceramic powder as a function of age

    Science.gov (United States)

    Scheinherrová, Lenka; Trník, Anton; Kulovaná, Tereza; Pavlík, Zbyšek; Rahhal, Viviana; Irassar, Edgardo F.; Černý, Robert

    2016-07-01

    The production of a cement binder generates a high amount of CO2 and has high energy consumption, resulting in a very adverse impact on the environment. Therefore, use of pozzolana active materials in the concrete production leads to a decrease of the consumption of cement binder and costs, especially when some type of industrial waste is used. In this paper, the hydration of blended cement pastes containing waste ceramic powder from the Czech Republic and Portland cement produced in Argentina is studied. A cement binder is partially replaced by 8 and 40 mass% of a ceramic powder. These materials are compared with an ordinary cement paste. All mixtures are prepared with a water/cement ratio of 0.5. Thermal characterization of the hydrated blended pastes is carried out in the time period from 2 to 360 days. Simultaneous DSC/TG analysis is performed in the temperature range from 25 °C to 1000 °C in an argon atmosphere. Using this thermal analysis, we identify the temperature, enthalpy and mass changes related to the liberation of physically bound water, calcium-silicate-hydrates gels dehydration, portlandite, vaterite and calcite decomposition and their changes during the curing time. Based on thermogravimetry results, we found out that the portlandite content slightly decreases with time for all blended cement pastes.

  1. Utilization of Iron Ore Tailings as Raw Material for Portland Cement Clinker Production

    Directory of Open Access Journals (Sweden)

    Li Luo

    2016-01-01

    Full Text Available The cement industry has for some time been seeking alternative raw material for the Portland cement clinker production. The aim of this research was to investigate the possibility of utilizing iron ore tailings (IOT to replace clay as alumina-silicate raw material for the production of Portland cement clinker. For this purpose, two kinds of clinkers were prepared: one was prepared by IOT; the other was prepared by clay as a reference. The reactivity and burnability of raw meal, mineralogical composition and physical properties of clinker, and hydration characteristic of cement were studied by burnability analysis, differential thermal analysis, X-ray diffraction, and hydration analysis. The results showed that the raw meal containing IOT had higher reactivity and burnability than the raw meal containing clay, and the use of IOT did not affect the formation of characteristic mineralogical phases of Portland cement clinker. Furthermore, the physical and mechanical performance of two cement clinkers were similar. In addition, the use of IOT was found to improve the grindability of clinker and lower the hydration heat of Portland cement. These findings suggest that IOT can replace the clay as alumina-silicate raw material for the preparation of Portland cement clinker.

  2. Industrial Fuel Flexibility Workshop

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2006-09-01

    On September 28, 2006, in Washington, DC, ITP and Booz Allen Hamilton conducted a fuel flexibility workshop with attendance from various stakeholder groups. Workshop participants included representatives from the petrochemical, refining, food and beverage, steel and metals, pulp and paper, cement and glass manufacturing industries; as well as representatives from industrial boiler manufacturers, technology providers, energy and waste service providers, the federal government and national laboratories, and developers and financiers.

  3. Manufacture and properties of fluoride cement

    Science.gov (United States)

    Malata-Chirwa, Charles David

    This research work aimed at characterising composition, hydration and physical properties of fluoride cement, by studying samples of the cement obtained from Malawi, and comparing them to ordinary Portland cement. By confirming the suitable characteristics of fluoride cement through this work, the results of the research work provide a good basis for the wider adoption of fluoride cement as an alternative to ordinary Portland cement, especially in developing economies. Numerous accounts have been cited regarding the production and use of fluoride cement. Since there have not been conclusive agreement as to its properties, this study was limited to the theories of successful incorporation of fluoride compounds in the manufacture of fluoride cement. Hence, the properties and characteristics reported in this study relate to the cement currently manufactured in Malawi, and, on a comparative basis only, to that manufactured in other parts of the world. Samples of the fluoride cement used in the study were obtained by synthetic manufacture of the cement using common raw materials for the manufacture of fluoride cement that is limestone, silica sand, and fluorspar. These samples were subjected to several comparative tests used to characterise cements including examination under x-ray diffractometer, scanning electron microscopy and tests for setting time and compressive strength. Under similar laboratory conditions, it was possible to prove that fluoride cement hardens more rapidly than ordinary Portland cement. Also observed during the experimental work is that fluoride cement develops higher compressive strengths than ordinary Portland cement. The hardening and setting times are significantly different between the two cements. Also the nature of the hydration products, that is the microstructural development is significantly different in the two cements. The differences brought about between the two cements are because of the presence of fluorine during the clinkering

  4. 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.

  5. Comparative Study of Clinker's Transformation at Different Temperature Zone During Cement Production

    Directory of Open Access Journals (Sweden)

    Mohd S. Idris

    2007-01-01

    Full Text Available Chemical composition analysis using x-ray fluorescence is one of the important quality analysis for examining of cement and widely used in cement industries for a long time as a tool to estimate phase composition. X-ray diffraction is one of the established techniques as a qualitative tool to identify phase existing in the sample. This study will discuss about the correlation between quantitative and qualitative analyses in order to understand phase transformation in production of cement. Qualitative analysis had revealed a lot of information which could not be identified by using x-ray fluorescence especially polymorphisms existed in the clinker samples.

  6. An ongoing investigation on modeling the strength properties of water-entrained cement-based materials

    DEFF Research Database (Denmark)

    Esteves, L.P.

    2012-01-01

    Water-entrained cement based materials by superabsorbent polymers is a concept that was introduced in the research agenda about a decade ago. However, a recent application in the production of high performance concrete revealed potential weaknesses when the proportioning of this intelligent...... material is not well performed, raising doubts among both academic and industrial society about the usability of superabsorbent polymers in cement-based materials. This work constitutes the baseline tentatively to be used on modeling the compressive strength of SF-modified water-entrained cement...

  7. Tendencias de la Educación universitaria en el siglo XXI

    Directory of Open Access Journals (Sweden)

    Ortega Castro, Vicente

    2002-09-01

    Full Text Available Not available

    El cambio de milenio ha propiciado muchos informes, libros y conferencias sobre la situación de las Universidades y los posibles cambios que se avecinaban como consecuencia de las tendencias de cambios en la sociedad, entre los que se encuentran el predominio del conocimiento, laglobalización y la influencia de nuevas tecnologías aplicadas al ámbito de la educación. Para la sociedad europea, en la que España está inmersa política, social y económicamente, es especialmente relevante la expectativa que está despertando la Declaración de Bolonia. Pues bien, tomando este documento como referencia principal, este artículo examina las funciones permanentes de la Universidad: creación de conocimientos, formación de profesionales, servicio a la sociedad y otros, teniendo en cuenta la importancia de la calidad, de la internacionalización, de la competitividad, de la movilidad, de la complejidad, de las nuevas demandas, de los nuevos esquemas de financiación y otros factores que hacen necesario que las Universidades comprendan las nuevas tendencia y hagan un esfuerzo, no solo de adaptación, sino de anticipación.

  8. The effect of cement creep and cement fatigue damage on the micromechanics of the cement-bone interface.

    Science.gov (United States)

    Waanders, Daan; Janssen, Dennis; Mann, Kenneth A; Verdonschot, Nico

    2010-11-16

    The cement-bone interface provides fixation for the cement mantle within the bone. The cement-bone interface is affected by fatigue loading in terms of fatigue damage or microcracks and creep, both mostly in the cement. This study investigates how fatigue damage and cement creep separately affect the mechanical response of the cement-bone interface at various load levels in terms of plastic displacement and crack formation. Two FEA models were created, which were based on micro-computed tomography data of two physical cement-bone interface specimens. These models were subjected to tensile fatigue loads with four different magnitudes. Three deformation modes of the cement were considered: 'only creep', 'only damage' or 'creep and damage'. The interfacial plastic deformation, the crack reduction as a result of creep and the interfacial stresses in the bone were monitored. The results demonstrate that, although some models failed early, the majority of plastic displacement was caused by fatigue damage, rather than cement creep. However, cement creep does decrease the crack formation in the cement up to 20%. Finally, while cement creep hardly influences the stress levels in the bone, fatigue damage of the cement considerably increases the stress levels in the bone. We conclude that at low load levels the plastic displacement is mainly caused by creep. At moderate to high load levels, however, the plastic displacement is dominated by fatigue damage and is hardly affected by creep, although creep reduced the number of cracks in moderate to high load region. PMID:20692663

  9. Cementation of Loose Sand Particles based on Bio-cement

    Institute of Scientific and Technical Information of China (English)

    RONG Hui; QIAN Chunxiang

    2014-01-01

    Loose sand particles could be cemented to sandstone by bio-cement (microbial induced magnesium carbonate). The bio-sandstone was firstly prepared, and then the compressive strength and the porosity of the sandstone cemented by microbial induced magnesium carbonate were tested to characterize the cementation effectiveness. In addition, the formed mineral composition and the microstructure of bio-sandstone were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The experimental results show that the feasibility of binding loose sand particles using microbial induced magnesium carbonate precipitation is available and the acquired compressive strength of bio-sandstone can be excellent at certain ages. Moreover, the compressive strength and the porosity could be improved with the increase of microbial induced magnesium carbonate content. XRD results indicate that the morphology of magnesium carbonate induced by microbe appears as needles and SEM results show that the cementation of loose sand particles to sandstone mainly relies on the microbial induced formation of magnesium carbonate precipitation around individual particles and at particle-particle contacts.

  10. Sifat Fisis dan Mekanis Papan Semen dari Limbah Industri Pensil Dengan Berbagai Rasio Bahan Baku dan Target Kerapatan

    OpenAIRE

    Lubis, Yunida Syafriani

    2015-01-01

    Pencil shavings utilization of industrial waste has not been developed. The main objective of this study was to evaluate the technical feasibility of pencil shavings industrial waste as raw materials of cement board and the research carried out for: 1) to determine the ratio of cement-particle density and the best targets for physical and mechanical properties of the resulting cement board; 2) evaluate the effect of the ratio of raw material and the target density on the quality of the cement...

  11. Sulfate attack and reinforcement corrosion in concrete with recycled concrete aggregates and supplementary cementing materials

    OpenAIRE

    Corral Higuera, Ramón; Arredondo Rea, Susana Paola; Neri Flores, M.A.; Gómez Soberón, José Manuel Vicente; Almeraya Calderón, F.; Castorena González, J.H.; Almaral Sánchez, Jorge Luis

    2011-01-01

    As strategies to contribute to the concrete industry sustainability, reinforced concrete was fabricated using recycled concrete coarse aggregate and replacing partially portland cement with supplementary cementing materials as fly ash and silica fume. On test specimens, partially immersed in 3.5% Na2SO4 aqueous solution, the effect of the recycled and supplementary materials against sulfate attack and reinforcement corrosion was evaluated. For such aim, weight loss of concrete and corrosion p...

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

    OpenAIRE

    E.G. Ameh; M. Onimisi; M.O. Lekdukun

    2014-01-01

    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, f...

  13. Recycling of red muds with the extraction of metals and special additions to cement

    Science.gov (United States)

    Zinoveev, D. V.; Diubanov, V. G.; Shutova, A. V.; Ziniaeva, M. V.

    2015-01-01

    The liquid-phase reduction of iron oxides from red mud is experimentally studied. It is shown that, in addition to a metal, a slag suitable for utilization in the construction industry can be produced as a result of pyrometallurgical processing of red mud. Portland cement is shown to be produced from this slag with mineral additions and a high-aluminate expansion addition to cement.

  14. Asbestos, cement, and cancer in the right part of the colon.

    OpenAIRE

    Jakobsson, K; Albin, M; Hagmar, L

    1994-01-01

    OBJECTIVE--The aim was to investigate associations between exposure to mineral fibres and dust, and cancer in subsites within the large bowel. DESIGN--Pooled retrospective cohort studies. SUBJECTS AND SETTINGS--Blue collar workers, employed for at least one year in different trades; asbestos cement or cement workers (n = 2507), other industrial workers (n = 3965), and fishermen (n = 8092). MAIN OUTCOME MEASURES--Standardised incidence ratios (SIRs, national reference rates) were calculated fo...

  15. Relation between lung function, exercise capacity, and exposure to asbestos cement.

    OpenAIRE

    Wollmer, P.; Eriksson, L.; Jonson, B.; Jakobsson, K; Albin, M; Skerfving, S; Welinder, H

    1987-01-01

    A group of 137 male workers with known exposure (mean 20 fibre years per millilitre) to asbestos cement who had symptoms or signs of pulmonary disease was studied together with a reference group of 49 healthy industrial workers with no exposure to asbestos. Lung function measurements were made at rest and during exercise. Evidence of lung fibrosis was found as well as of obstructive airways disease in the exposed group compared with the reference group. Asbestos cement exposure was related to...

  16. Effect of the addition of nanosilica on white cement hydration at 25°C

    OpenAIRE

    Sáez del Bosque I.F.; Martínez-Ramírez S.; Martín-Pastor M.; Teresa Blanco-Varela M.

    2014-01-01

    The cement industry is keen on reducing natural resource consumption, reusing waste that would otherwise be sent to a rubbish tip and lowering its CO2 emissions. In pursuit of those objectives, the addition of materials such as silica fume, ceramic waste, rice husk and precipitated or colloidal nanosilica, in the various stages of cement manufacture has become increasingly common. That practice inspired the present study (using isothermal conduction calorimetry, 29Si and 27Al MAS NMR, XRD and...

  17. Effect of nanosilica addition on White cement hydration at 25ºC.

    OpenAIRE

    Sáez del Bosque, I. F.; Martínez Ramírez, Sagrario; Martín-Pastor, Manuel; Blanco-Varela, María Teresa

    2013-01-01

    The cement industry is keen on reducing natural resource consumption, reusing waste that would otherwise be sent to a rubbish tip and lowering its CO2 emissions. In pursuit of those objectives, the addition of materials such as silica fume, ceramic waste, rice husk and precipitated or colloidal nanosilica, in the various stages of cement manufacture has become increasingly common. That practice inspired the present study (using isothermal conduction calorimetry, 29Si and 27Al MAS NMR, XRD and...

  18. Utilization of “Marble Slurry” In Cement Concrete Replacing Fine Agreegate

    Directory of Open Access Journals (Sweden)

    Er: Raj.p.singh kushwah

    2015-01-01

    Full Text Available The wastage of marble industry are responsible for many environmental problems because 70% wastes and only 30% recovery of main product contribute to the maximum wastes which are indestructible. Dumping sites give dirty look. Contaminate top fertile soil cover, along with rivers/water bodies affecting irrigation and drinking water resources and air as well as loss to flora and fauna. The most efficient Solution of marble slurry pollution is utilization in Bulk. The only industry which can consume marble slurry at so large level is only the construction industry. Different properties of marble slurry determined in the laboratory. Sp. gravity 2.61, Fineness modulus was found to be 0.91 and Utilization of marble slurry in Cement Concrete replacing Sand is 30% which shows equal strength as of Control i,e. 1:2:4 Cement Concrete 0% Marble slurry. Marble slurry can be easily utilized in construction industry in preparing Cement Concrete.

  19. Technological tendencies and their relation with energy markets; Tendencias tecnologicas y su relacion con mercados de energia

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Castro, Salvador [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    1999-07-01

    In this article some associate technological tendencies with areas of interest of the Control Systems Division of the Instituto de Investigaciones Electricas (IIE) are presented. Here the relations or influence that these tendencies have and will continue having in the future with the definition and implantation of energy markets are mentioned. [Spanish] En este articulo se presentan algunas tendencias tecnologicas asociadas con areas de interes de la Division de Sistemas de Control del Instituto de Investigaciones Electricas (IIE). Aqui se mencionan las relaciones o influencia que dichas tendencias tienen y continuaran teniendo en el futuro con la definicion e implantacion de mercados de energia.

  20. Tendencias en la distribución de probabilidades de lluvias y caudales en Antioquía.

    OpenAIRE

    Rave Herrera, Claudia Cristina; Mantilla Gutiérrez, Ricardo; Poveda Jaramillo, Germán

    2000-01-01

    Se estudia una metodología para el análisis de cambios y tendencias de los cuantiles de las distribuciones de probabilidades de series de registros de lluvias y caudales diarios en Antioquia, para las cuales ya existian resultados de analisis de tendencias y cambios en la media y la varianza. El análisis de cuantiles verificó dichos resultados y aporto importantes conclusiones sobre los fenómenos fisicos involucrados en los cambios; además de un acercamiento mas serio en la consideración de u...

  1. Some future tendencies in the electric power systems; Algunas tendencias futuras en los sistemas electricos de potencia

    Energy Technology Data Exchange (ETDEWEB)

    Sarmiento Uruchurtu, Hector Gerardo [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1995-12-31

    This document describes the most important tendencies on energy generation transmission and utilization of the electric power systems. The underlining of these tendencies has the purpose of maintaining a constant alert on the possible technological advances that must be covered at medium and long term in the Coordination Analysis of Transmission Systems [Espanol] En el presente documento se describen las tendencias mas importantes sobre generacion, transmision y utilizacion de la energia, en cuanto a los sistemas electricos de potencia. El destacar estas tendencias tiene por objeto una alerta constante sobre los posibles desarrollos tecnologicos que se deben abordar a mediano y largo plazo dentro de la Coordinacion de Analisis de Sistemas de Transmision

  2. Consumo de tabaco de los adolescentes en Barcelona y tendencias a lo largo de 20 años

    OpenAIRE

    Carles Ariza; Xavier García-Continente; Joan Ramon Villalbí; Francesca Sánchez-Martínez; Anna Pérez; Manel Nebot

    2014-01-01

    Objetivos: El tabaquismo es causa de muerte prematura y prevenible, que se inicia en la adolescencia. Se describe el consumo de tabaco en escolares durante 2008 y la tendencia en los últimos 20 años en Barcelona. Material y métodos: Estudio de análisis de la tendencia del consumo. Se comparan datos de ocho encuestas realizadas entre 1987 y 2008 en 2° y 4° cursos de Educación Secundaria Obligatoria (ESO) y 2° de Bachillerato o Ciclos Formativos de Grado Medio. Se utilizó el cuestionario FRE...

  3. Definición de las tendencias de fertilidad en suelos cafeteros de Charalá, Coromoro y Ocamonte (Santander)

    OpenAIRE

    Héctor Giovanny Galindo-Barrera

    2013-01-01

    Objetivo: Definir las tendencias de fertilidad en suelos cafeteros de Charalá, Coromoro y Ocamonte (Santander). Materiales y métodos. Se utilizó un importante número de análisis de suelos que permitieron recopilar 1485 muestras tomadas desde el año 1991, y que sirvieron como banco de datos para generar tendencias de fertilidad en los suelos cultivados con café de los municipios de Charalá, Coromoro y Ocamonte. Posteriormente, los datos fueron agrupados y organizados a nivel seccional, municip...

  4. Seepage/Cement Interactions

    International Nuclear Information System (INIS)

    The Development Plan (CRWMS M andO 1999a) pertaining to this task defines the work scopes and objectives for development of various submodels for the Physical and Chemical Environment Abstraction Model for TSPA-LA. The Development Plan (CRWMS M andO 1999a) for this specific task establishes that an evaluation be performed of the chemical reactions between seepage that has entered the drift and concrete which might be used in the repository emplacement drifts. The Development Plan (CRWMS M andO 1999a) then states that the potential effects of these water/grout reactions on chemical conditions in the drift be assessed factoring in the influence of carbonation and the relatively small amount of grout. This task is also directed at: (1) developing a conceptualization of important cement/seepage interactions and potential impacts on EBS performance, (2) performing a screening analysis to assess the importance of cement/seepage interactions. As the work progresses and evolves on other studies, specifically the Engineered Barrier System: Physical and Chemical Environment (P andCE) Model (in progress), many of the issues associated with items 1 and 2, above, will be assessed. Such issues include: (1) Describing the mineralogy of the specified cementitious grout and its evolution over time. (2) Describing the composition of the water before contacting the grout. (3) Developing reasonable upper-bound estimates for the composition of water contacting grout, emphasizing pH and concentrations for anions such as sulfate. (4) Evaluating the equilibration of cement-influenced water with backfill and gas-phase CO2. (5) Developing reasonable-bound estimates for flow rate of affected water into the drift. The concept of estimating an ''upper-bound'' range for reaction between the grout and the seepage, particularly in terms of pH is based on equilibrium being established between the seepage and the grout. For example, this analysis can be based on equilibrium being established as

  5. Spent FCC catalyst for improving early strength Portland cement

    OpenAIRE

    Borrachero Rosado, María Victoria; Monzó Balbuena, José Mª; Paya Bernabeu, Jorge Juan; Vunda, Christian; Velázquez Rodríguez, Sergio; Soriano Martinez, Lourdes

    2014-01-01

    Spent fluid catalytic cracking (FCC) catalyst from the petrol industry has proven to be a very active pozzolanic material. This behavior leads to an additional increase in the strength of the mortar that contains this catalyst. Pozzolanic effects tend to be considered for periods above three days, whereas in shorter times, the influence of pozzolan is usually negligible. The reactivity of FCC is so high, however, that both pozzolanic effects and acceleration of cement hydration are evident in...

  6. Co-TiC CEMENTED CARBIDES. STRUCTURAL ASPECT

    OpenAIRE

    Volikova, A.; National Aviation University, Kyiv

    2012-01-01

     To increase wear resistance of turbine blades top shrouds plates made of different cast alloys are used. For this task current paper proposes Co-TiC cemented carbides. To evaluate prospective of their use in gas turbines it is necessary analize their microstructure and compare it with other alloys, particularly with industrial cast eutectic alloy XTH-62 and alloy P-69 [1].

  7. THE INFLUENCE OF THE COMPLEX CHEMICAL ADDITIVE CONTAINING THE STRUCTURED CARBON NANOMATERIAL ON PROPERTIES OF CEMENT

    Directory of Open Access Journals (Sweden)

    O. Yu. Sheyda

    2015-01-01

    Full Text Available The paper presents results of investigations on influence of domestic complex chemical additive containing structured carbon nanomaterial and characterized by a combination effect (curing acceleration and plasticizing on cement and cement stone properties. The purpose of the investigations, on the one hand, has been to confirm efficacy of УКД-1additive from the perspective for increasing the rate of gain, strength growth of cement concrete and additive influence on setting time with the purpose to preserve molding properties of concrete mixes in time, and on the other hand, that is to assess “mechanism” of the УКД-1 additive action in the cement concrete. The research results have revealed regularities in changes due to the additive of water requirements and time period of the cement setting. The reqularities are considered as a pre-requisite for relevant changes in molding properties of the concrete mixes. The paper also experimentally substantiates the possibility to decrease temperature of cement concrete heating with the УДК-1 additive. It has been done with the purpose to save energy resources under production conditions. In addition to this the paper proves the efficiency of the additive which is expressed in strength increase of cement stone up to 20–40 % in the rated age (28 days that is considered as a basis for strength growth of cement concrete. The paper confirms a hypothesis on physical nature of this phenomenon because the X-ray phase analysis method has shown that there are no changes in morphology of portland cement hydration products under the action of the additive agent containing a structured carbon nanomaterial. Results of theoretical and experimental investigations on УКД-1 additive efficiency have been proved by industrial approbation while fabricating precast concrete products and construction of monolithic structures under plant industrial conditions (Minsk, SS “Stroyprogress” JSC MAPID and on

  8. A modified PMMA cement (Sub-cement) for accelerated fatigue testing of cemented implant constructs using cadaveric bone.

    Science.gov (United States)

    Race, Amos; Miller, Mark A; Mann, Kenneth A

    2008-10-20

    Pre-clinical screening of cemented implant systems could be improved by modeling the longer-term response of the implant/cement/bone construct to cyclic loading. We formulated bone cement with degraded fatigue fracture properties (Sub-cement) such that long-term fatigue could be simulated in short-term cadaver tests. Sub-cement was made by adding a chain-transfer agent to standard polymethylmethacrylate (PMMA) cement. This reduced the molecular weight of the inter-bead matrix without changing reaction-rate or handling characteristics. Static mechanical properties were approximately equivalent to normal cement. Over a physiologically reasonable range of stress-intensity factor, fatigue crack propagation rates for Sub-cement were higher by a factor of 25+/-19. When tested in a simplified 2 1/2-D physical model of a stem-cement-bone system, crack growth from the stem was accelerated by a factor of 100. Sub-cement accelerated both crack initiation and growth rate. Sub-cement is now being evaluated in full stem/cement/femur models. PMID:18774136

  9. The effect of supplementary pulverized fuel ash on calcium aluminate phosphate cement for intermediate-level waste encapsulation

    International Nuclear Information System (INIS)

    The objective of the current study was to evaluate the effects of supplementary pulverized fuel ash on phosphate-modified calcium aluminate cement. These systems are being established as part of a wider project to develop alternative cementing systems for the encapsulation of problematic low- and intermediate- level radioactive waste in the UK. The nuclear industry has established specific processing and property criteria, which must be fulfilled to ensure suitability for industrial application. In a series of studies, pulverized fuel ash was used as a partial replacement for calcium aluminate cement, to improve the fluidity of the system and increase the setting time. Properties such as slurry pH and fluidity, setting time, mechanical properties, and porosity were investigated using Vicat, Colflow, and compressive strength testing equipment and mercury intrusion porosimetry. The hardened cement pastes were also characterised using X-ray diffraction, thermogravimetric analysis and scanning electron microscopy. A formulation envelope was identified, which fulfilled the plant acceptance tests defined by industry to ensure suitability for industrial application. It was found that pH of calcium aluminate phosphate cements is lower than that of conventional cementing systems used to encapsulate radioactive waste in the UK. Hence, they have potential to be used as an alternative cementing system for the encapsulation of problematic radioactive metals. (authors)

  10. Seating load parameters impact on dental ceramic reinforcement conferred by cementation with resin-cements.

    LENUS (Irish Health Repository)

    Addison, Owen

    2010-09-01

    Cementation of all-ceramic restorations with resin-cements has been demonstrated to reduce the incidence of fracture in service. The aim was to investigate the influence of loading force and loading duration applied during cementation on the reinforcement conferred by a resin-cement on a leucite reinforced glass-ceramic.

  11. Retention of Root Canal Posts: Effect of Cement Film Thickness, Luting Cement, and Post Pretreatment

    DEFF Research Database (Denmark)

    Sahafi, Alireza; Benetti, Ana Raquel; Peutzfeldt, Anne; Flury, Simon

    2015-01-01

    The aim of this study was to investigate the effect of the cement film thickness of a zinc phosphate or a resin cement on retention of untreated and pretreated root canal posts. Prefabricated zirconia posts (CosmoPost: 1.4 mm) and two types of luting cements (a zinc phosphate cement [DeTrey Zinc...

  12. [Antimicrobial activity of orthodontic band cements].

    Science.gov (United States)

    Pavic, J; Arriagada, M; Elgueta, J; García, C

    1990-01-01

    The prevalence of enamel decalcification and caries beneath orthodontic bands, has indicated the need for a new enamel binding adhesive orthodontic cement. The purpose of this study was to evaluate the antimicrobial activity, in vitro, on Streptococcus mutans and Lactobacillus, acidophillus, of three materials used to cements the orthodontic bands. The cements studied were: Zinc phosphate cement, Glass-ionomer cement, and Policarboxylate cement. Thirty petri plates were seeded with S. mutans, and thirty with L. acidophillus; on each plate three pellet were placed, one of each cement studied. Petri plates were incubated under microaerophilic conditions at 37 C, and checked at 72 hrs. for Streptococcus, mutans, and four days for Lactobacillus acidophillus to evaluate the inhibition zone. The results were tabulated for each material. It was demonstrated that exists important variations in the antimicrobial properties of the materials studied, as in the microbial sensitivity to these cements. PMID:2135908

  13. Micro Mechanics and Microstructures of Major Subsurface Hydraulic Barriers: Shale Caprock vs Wellbore Cement

    Science.gov (United States)

    Radonjic, M.; Du, H.

    2015-12-01

    Shale caprocks and wellbore cements are two of the most common subsurface impermeable barriers in the oil and gas industry. More than 60% of effective seals for geologic hydrocarbon bearing formations as natural hydraulic barriers constitute of shale rocks. Wellbore cements provide zonal isolation as an engineered hydraulic barrier to ensure controlled fluid flow from the reservoir to the production facilities. Shale caprocks were deposited and formed by squeezing excess formation water and mineralogical transformations at different temperatures and pressures. In a similar process, wellbore cements are subjected to compression during expandable tubular operations, which lead to a rapid pore water propagation and secondary mineral precipitation within the cement. The focus of this research was to investigate the effect of wellbore cement compression on its microstructure and mechanical properties, as well as a preliminary comparison of shale caprocks and hydrated cement. The purpose of comparative evaluation of engineered vs natural hydraulic barrier materials is to further improve wellbore cement durability when in contact with geofluids. The micro-indentation was utilized to evaluate the change in cement mechanical properties caused by compression. Indentation experiments showed an overall increase in hardness and Young's modulus of compressed cement. Furthermore, SEM imaging and Electron Probe Microanalysis showed mineralogical alterations and decrease in porosity. These can be correlated with the cement rehydration caused by microstructure changes as a result of compression. The mechanical properties were also quantitatively compared to shale caprock samples in order to investigate the similarities of hydraulic barrier features that could help to improve the subsurface application of cement in zonal isolation. The comparison results showed that the poro-mechanical characteristics of wellbore cement appear to be improved when inherent pore sizes are shifted to

  14. Cement radwaste solidification studies third annual report

    International Nuclear Information System (INIS)

    This report summarises cement radwaste studies carried out at AEE Winfrith during 1981 on the encapsulation of medium and low active waste in cement. During the year more emphasis has been placed on the work which is directly related to the solidification of SGHWR active sludge. Information has been obtained on the properties of 220 dm3 drums of cemented waste. The use of cement grouts for the encapsulation of solid items has also been investigated during 1981. (U.K.)

  15. Cement Sheath Integrity During Thermal Cycling

    OpenAIRE

    Andrade, Jesús De

    2015-01-01

    In the construction process of oil and gas wells, primary cementing constitutes a critical procedure of placing a cement sheath in the annulus between casing and formation, or between the casing strings. The main purpose is to provide mechanical stability to the wellbore and to ensure zonal isolation through the entire well service lifetime. Failures to achieve a proper primary cementing, and to ensure long-term sealing capabilities of the cement sheath, may severely limit the abi...

  16. Neutron Scattering Studies of Cement

    Science.gov (United States)

    Allen, Andrew

    2010-03-01

    Despite more than a century of research, basic questions remain regarding both the internal structure and the role of water in Ordinary Portland cement (OPC) concrete, the world's most widely used manufactured material. Most such questions concern the primary hydration product and strength-building phase of OPC paste, the calcium silicate hydrate (C-S-H) gel. When cement and water are mixed, this phase precipitates as clusters of nanoscale (nearly amorphous) colloidal particles with an associated water-filled inter-particle pore system. Most attempts to characterize the C-S-H gel and the behavior of the associated water involve drying or other processes that, themselves, change the bound water content within and around the gel. Neutron scattering methods do not suffer from this disadvantage. Furthermore, the neutron isotope effect and the neutron's sensitivity to molecular motion have enabled considerable progress to be made in recent years by: (i) determining the C-S-H composition, density and gel structure in small-angle neutron scattering (SANS) H/D contrast variation studies; (ii) elucidating the changing state of water within cement as hydration progresses using quasielastic neutron scattering (QENS); and (iii) measuring the production and consumption of nanoscale calcium hydroxide (CH), a by-product of cement hydration that co-exists with the C-S-H gel, using inelastic neutron scattering (INS). These experiments have provided new insights into the physics and chemistry of cement hydration, and have implications for the design of new concretes with pozzolanic cement additions that are intended to address environmental concerns and sustainability issues.

  17. PERFORMANCE OF PULVERIZED SLAG-SUBSTITUTED CEMENT

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

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

  18. Microscale Investigation of Arsenic Distribution and Species in Cement Product from Cement Kiln Coprocessing Wastes

    OpenAIRE

    Yufei Yang; Jingchuan Xue; Qifei Huang

    2013-01-01

    To improve the understanding of the immobilization mechanism and the leaching risk of Arsenic (As) in the cement product from coprocessing wastes using cement kiln, distribution and species of As in cement product were determined by microscale investigation methods, including electron probe microanalysis (EPMA) and X-ray absorption spectroscopy. In this study, sodium arsenate crystals (Na3AsO412H2O) were mixed with cement production raw materials and calcined to produce cement clinker. Then, ...

  19. The comparison between sulfate salt weathering of portland cement paste and calcium sulfoaluminate cement paste

    OpenAIRE

    Liu, Zanqun; Deng, Dehua; De Schutter, Geert

    2015-01-01

    In this paper, the damage performances of sulfate salt weathering of Portland cement paste and calcium sulfoaluminate (CSA) cement paste were compared according to authors' previous studies. It was found that the evaporation zone of speciments partially immersed in 10% Na2SO4 solution were both severely deteriorated for Portland cement and CSA cement. However, the differences were more significant: (1) the CSA cement paste were damaged just after 7 days exposure compared to the 5 months expos...

  20. 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.

  1. Tendencias de la historia regional en Colombia. Problemas y perspectivas recientes

    Directory of Open Access Journals (Sweden)

    Renzo Ramírez Bacca

    2011-06-01

    Full Text Available El texto ofrece un balance de los estudios regionales en Colombia. Los elementos de la interpretación que tiene el autor son los siguientes: 1 Una comprensión contextual sobre la institucionalización de la disciplina. 2 Un análisis sobre las posibilidades y problematización del concepto Región. 3 Un balance crítico sobre la producción monográfica regional, con énfasis especial en el caso antioqueño. Y, 4 una mirada sobre las tendencias recientes en los estudios regionales a partir de la producción visible en el Sistema Nacional de Investigación y Colciencias, e información ofrecida por algunos departamentos de historia del país.

  2. Coherencia de tendencias en cosmética, con procesos de I+D en BELCORP

    Directory of Open Access Journals (Sweden)

    Iván Felipe Acosta

    2016-07-01

    Full Text Available La constante necesidad de las empresas por actualizarse o reinventarse para mantenerse vigentes en el mercado ha llevado a que tengan como estrategia la implementación de modelos de Innovación y Desarrollo (I+D. BELCORP, una empresa del sector cosmético ha implementado un sistema denominado Stage Gate, una metodología eficiente para el desarrollo de productos que comprende desde la conceptualización hasta la etapa posterior al lanzamiento y la comercialización de sus productos. Para garantizar su éxito, BELCORP tiene como estrategia mantenerse al día con las tendencias de la moda vigente pero, para lanzar sus productos también está considerando otros factores como los gustos de los consumidores, la cultura y las posibilidades tecnológicas existentes en los mercados donde tiene presencia.

  3. Tendencia de la incidencia de los tumores hepáticos en la infancia

    Directory of Open Access Journals (Sweden)

    Mejía-Aranguré Juan Manuel

    2002-01-01

    Full Text Available Objetivo. Evaluar la tendencia de la incidencia de los diferentes tumores hepáticos en niños residentes en el Distrito Federal. Material y métodos. Encuesta hospitalaria. Se realizó un análisis de dos bases de datos. La primera tiene registrados todos los casos de tumores hepáticos que se encontraron entre el periodo de l982 a 1991, de hospitales que atienden a niños con cáncer, residentes en la Ciudad de México. La segunda base de datos tiene registrados todos los casos de tumores hepáticos que se encontraron de 1996 a 1999 en el Hospital de Pediatría Centro Médico Nacional (CMN "Siglo XXI" y en el Hospital General del Centro Médico Nacional "La Raza", del Instituto Mexicano del Seguro Social (IMSS. Se calcularon las tasas de incidencia anual promedio (TIAP por cada tipo de tumor hepático. Las tasas fueron estandarizadas por el método directo, usando como población de referencia a la mundial estándar menor de l5 años. La tendencia se evaluó con las tasas de incidencia anuales y se calculó la tasa de cambio promedio que emplea la distribución de Poisson. Resultados. Durante el periodo de 1982 a 1991 la TIAP para hepatoblastoma fue el triple en hombres con 0.6 x 10(6. El grupo más afectado fue el de 1 a 4 años.(Para los hepatocarcinomas la TIAP fue de 0.14 para el sexo femenino, siendo el doble que la del sexo masculino. Para el periodo de 1996 a 1999 la TIAP para hepatoblastomas fue de 5.11 en mujeres y de 1.85 en hombres. El grupo de edad con la tasa más alta fue el de mujeres menores de un año. Para hepatocarcinomas la TIAP fue de 0.64 para hombres y de 1.23 en mujeres. El grupo de edad más afectado fue el de hombres de 10 a 14 años. No se observó tendencia significativa al incremento o decremento en la incidencia de hepatoblastomas. Para hepatocarcinomas hubo una tasa de cambio de 10%, pero tampoco fue significativa. Conclusiones. No existe en la Ciudad de México una tendencia en la incidencia de los tumores hep

  4. Inferencia del proceso de pensamiento estratégico basado en modelos y tendencias

    Directory of Open Access Journals (Sweden)

    Denys García de Mujica

    2006-01-01

    Full Text Available El propósito del estudio fue inferir acerca del Proceso de Pensamiento Estratégico. La investigación se clasificó de tipo descriptivo documental. La población estuvo conformada por diez modelos y/o tendencias. Se utilizó como instrumento de recolección una matriz de análisis, lo que permitió obtener como resultado que el pensamiento estratégico se apalanca en el análisis, la innovación, creatividad y propuestas disruptivas para acceder a nuevos mercados. Todo esto sirvió de base para proponer un modelo según el cual se requiere utilizar inteligencia de negocio, estudios prospectivos, revisión continua de paradigmas y ortodoxias, entre otros, para redefinir los futuros posibles.

  5. Cadenas de rodillos. Tendencias de desarrollo y dimensionales según normas ISO.

    Directory of Open Access Journals (Sweden)

    M. E. García Domínguez

    2007-05-01

    Full Text Available El artículo es una compilación de resultados derivados de un estudio del desarrollo de la transmisión por cadena de rodillos que permite brindar información relevante sobre la tendencia del mercado internacional, innovaciones recientes en las cadenas de rodillos y las diferencias dimensionales que caracterizan las series geométricas de las cadenas ISO-A e ISO-B según la norma ISO 606:2004The paper is a compilation of some results associated with the development of roller chain transmissions and outstanding information in relations with the roller chain market trend, recent innovations and dimensional differences of ISO-A and ISO-B roller chain series according to ISO Standard 606:2004.

  6. Diagnóstico y tendencias económicas del Corredor Tijuana-Rosarito-Ensenada

    Directory of Open Access Journals (Sweden)

    Wilfrido Ruiz Ochoa

    2015-01-01

    Full Text Available En este artículo se proponen estrategias que pudieran implementarse para romper con un escenario económico inercial adverso que, hipotéticamente, pudiera restarle viabilidad económica a futuro al Corredor Costero Tijuana- Rosarito-Ensenada. Esto, a partir de un diagnóstico económico sustentado en índices multidimensionales, en el que se aporta información censal sobre el perfil sectorial y espacial del corredor, así como de sus tendencias de crecimiento para 2030. Sobre esta base se elaboran propuestas para afrontar la desaceleración económica reciente de la zona, mediante la identificación de sus vocaciones económicas y de algunos proyectos estratégicos.

  7. Tendencias mundiales en educación médica Tendencias mundiales en educación médica

    Directory of Open Access Journals (Sweden)

    Ricardo Posada Saldarriaga

    2004-02-01

    Full Text Available This article presents a general view of some considerations made by medical educators in the world, with the objective to leave to the reader elements for the reflection and the possibilitie of propose new educative strategies. It has the purpose of sugesting new Educative strategies for medical education in our country as in other regions of the world. The propose tendencies are: Globalization multidisciplinal activities and fortification of some areas within the curriculum of medicina, such as: Basic sciences, Investigation, Public Health and the Humanistic formation. Aditionally, some methodologies of education have appeared that have demonstrated to be complement of traditional classroom activities, laboratory and clinical rotations. Some of these methodologies are mentioned: simulation, use of technologies of information and communication (TIC, Evidence Based Medicine (EBM and Based Problem Learning. To confront the new challenges raised worldwide in the medical education and to maintain high quality standards, it is necessary that faculties of medicine understand the accelerated changes that are presently occurring. It is necessary to innovate in educational methodologies that foment the selflearning and active participation in learning process, implement the new information technologies, fortify the interrelation between basic and clinics sciences, thus fomenting partner-humanistic formation and public health aspects, creating research lines in which the students may participate actively to promote a flexible curriculum which allows our students to strenghten knowledge areas of their interest. Este artículo presenta de manera general algunas reflexiones hechas por educadores médicos en el mundo, con el objetivo de dejar al lector elementos para la reflexión y para la proposición de nuevas estrategias educativas en su quehacer docente. Se presentan las que a nuestro juicio pueden ser consideradas tendencias para la educación de los m

  8. PRÁCTICAS LECTORAS: COMPRENSIÓN Y EVALUACIÓN. TENDENCIAS, ESTADO Y PROYECCIONES

    Directory of Open Access Journals (Sweden)

    Jairo Aníbal Moreno Castro

    2010-06-01

    Full Text Available En este artículo se revisan, discuten y sistematizan asuntos teóricos fundamentales que apoyan la primera fase de la investigación "Evaluación de los niveles de lectura en el contexto de la educación superior", desarrollada durante el periodo 2009-2010. El concepto de lectura, las conexiones que tal modalidad comunicativa humana sostiene con la comprensión discursiva y, finalmente, las perspectivas y estrategias evaluativas de la comprensión lectora en entornos académicos institucionalizados son los ejes temáticos del artículo. Este último se propone señalar con precisión tanto el estado como las tendencias y proyecciones conceptuales y programáticas de tales nodos temáticos. Con el propósito de fortalecer la consistencia conceptual, facilitar la comprensión crítica y aligerar la textura académica del artículo, el análisis de los documentos revisados se presenta integrado alrededor de cuatro tópicos considerados como las tendencias conceptuales nucleares: 1 el tránsito de lo sensorial a lo racional y de lo racional a lo sociocultural transaccional, 2 el tránsito del significante al significado y de allí al sentido, 3 el tránsito de lo textual a lo intertextual y de allí a lo contextual (lo literal, lo inferencial, lo crítico, y 4 el tránsito de la lectura como comportamiento a la lectura como proceso.

  9. Trabajo y salud en la industria maquiladora mexicana: una tendencia dominante en el neoliberalismo dominado

    Directory of Open Access Journals (Sweden)

    Jorge Villegas

    1997-01-01

    Full Text Available Se analizan las condiciones laborales y de salud de los trabajadores de la Industria Maquiladora de Exportación en México. Hace uso intensivo de la fuerza de trabajo mayoritariamente femenina,constituye la segunda fuente de divisas. Ilustra una tendencia dominante en el neoliberalimo respecto a condiciones de trabajo y salud, permite apreciar el impacto de la generalizada flexibilización laboral y del creciente cambio tecnológico. El panorama de los riesgos y exigencias es complejo. En la organización laboral persisten exigencias del taylorismo, los riesgos químicos son múltiples y con probables efectos que rebasan el ámbito laboral, también existen exigencias de trabajo repetitivo y posiciones incómodas. Las repercusiones en la salud muestran elevados índices de morbilidad por demanda en los servicios de seguridad social, entre 2 y 4 veces más altos que para otros trabajadores industriales. Padecimientos asociados al estrés ocupan elevado porcentaje entre los motivos de consulta. También se muestran repercusiones en las familias, el bajo peso al nacer de los hijos es un riesgo 2.8 veces mayor para obreras de la maquila respecto de otros grupos de trabajadoras. Los accidentes laborales alcanzan cifras elevada y llegando a ser la segunda causa de consulta en algunos casos. Este análisis permite identificar algunas tendencias que en la salud laboral pueden ser importantes en los próximos años para amplios grupos de trabajadores.

  10. Una mirada conjugada en la gestión cultural estadounidense: tendencias actuales.

    Directory of Open Access Journals (Sweden)

    Jodie Dinapoli Algarra

    2015-06-01

    Full Text Available Debido al descenso que se experimenta en Estados Unidos en la participación del público en los eventos culturales, las instituciones y organizaciones culturales ponen el énfasis en cómo desarrollar un nuevo público y reflexionan sobre el impacto que pueden alcanzar más allá de sus paredes físicas. Este impacto se dirige al desarrollo humano, a la revitalización urbana, al bienestar social y a la creación activa de la cultura. En línea con esta misión y visión encontramos actividades y programas que se llevan a cabo en espacios no tradicionales, que expanden la cooperación social desplazando el foco institucional hacia la creatividad, dirigiendo el objetivo hacia el diálogo crítico, construyendo participación cultural significativa, desafiando el paisaje interno de la organización y sus procesos para servir mejor a la comunidad y a su entorno.  Este artículo analiza esta tendencia por medio de casos específicos de instituciones de artes visuales y estudia conceptos comunes que entran en juego tales como la cooperación social y el valor público. Este texto incorpora un contexto histórico y cuestiona la percepción pública de estas tendencias y su relación con el sector sin ánimo de lucro y su particular modelo de financiación.

  11. Tendencias de mortalidad por traumatismos y envenenamientos en adolescentes: México, 1979-1997

    Directory of Open Access Journals (Sweden)

    Celis Alfredo

    2003-01-01

    Full Text Available OBJETIVO: Describir las causas externas de la mortalidad por traumatismos y envenenamientos, así como la tendencia que estas causas han mostrado entre adolescentes en México, de 1979 a 1997. MATERIAL Y MÉTODOS: Para la realización de este estudio descriptivo de la mortalidad se utilizaron las bases de datos de mortalidad registrada en México de 1979 a 1997. Los datos son recabados, codificados y capturados por el Instituto Nacional de Estadística, Geografía e Informática, y se obtuvieron a través del Instituto Nacional de Salud Pública. Los datos fueron tabulados durante el último semestre de 2000, en Jalisco, en la Unidad de Investigación Epidemiológica y en Servicios de Salud del Adolescente del Instituto Mexicano del Seguro Social. RESULTADOS: Los traumatismos y envenenamientos ocuparon el primer lugar en la mortalidad del grupo adolescente (tasa de 13.35/100 000 con una tendencia descendente de -41.4% durante el periodo 1979-1997, no obstante el incremento de homicidios y suicidios (9.5% y 104.0% respectivamente. Los mecanismos más frecuentes fueron los vehículos de tráfico de motor, las armas de fuego, las intoxicaciones, las sofocaciones y las asfixias por inmersión. CONCLUSIONES: Los traumatismos y envenenamientos que experimenta la población de países en desarrollo muestran frecuencias diferentes a lo registrado en los más desarrollados, haciendo necesario el estudio de los mismos para implantar las medidas preventivas acordes con las condiciones socioculturales y ambientales de cada entorno.

  12. Investigation of the volume instability of ion exchange resins embedded in cement

    International Nuclear Information System (INIS)

    Ion exchange resins (IERs) are widely used by nuclear industry to decontaminate radioactive effluents. Spent resins have to be conditioned and the cementation process is adequate, relatively simple and inexpensive. However, several specificities of IERs have to be taken into account to design a cement formula: -) their ability to exchange ions with the cementitious medium, which may influence the cement hydration process, -) their low mechanical strength, which strongly weakens the compressive strength of the solidified waste forms, -) their strong dimensional variations which can, under severe conditions, induce swelling and cracking of the cement-based matrix. These dimensional variations can result from various processes: osmotic pressure and ion exchange in saturated medium, relative humidity variations in de saturated medium. Free deformations of IERs are measured as a function of different parameters: nature of the ions fixed on the functional groups, ionic strength of the aqueous solution in which the resins are immersed, water saturation degree of the resins. Particular attention is also paid to the quantification of swelling pressures induced by resins in a confined environment, as it may be the case in the cement-based matrix. Cements containing high amounts of blast-furnace slag are more appropriate than Portland cement (OPC) to solidify cationic IERs saturated with sodium or potassium. The rapid expansion observed during the first days of hydration with OPC can indeed be strongly reduced with the blended binders

  13. INVESTIGATING EFFECTS OF INTRODUCTION OF CORNCOB ASH INTO PORTLAND CEMENTS CONCRETE: MECHANICAL AND THERMAL PROPERTIES

    Directory of Open Access Journals (Sweden)

    Antonio Price

    2014-01-01

    Full Text Available The purpose of this study was to evaluate the benefits of replacing Ordinary Portland Cement (OPC with Corncob Ash (CCA blended cements. The cement industry contributes considerable amount of Carbon Dioxide (CO2 emissions into the atmosphere. The main contribution of CO2 emissions from cement production results from the process of creating Calcium Oxide (CaO from limestone (CaCO3 commonly known as the calcination process. Blending OPC with a pozzolanic material will assist in the reduction of CO2 emissions due to calcination as well as enhance the quality of OPC. There are various pozzolanic materials such as fly ash, rice husk, silica fume and CCA that could be promising partial replacement for OPC. In this study, CCA will serve as the primary blending agent with OPC. An experiment was performed to designate an appropriate percentage replacement of CCA that would comply with specific standards of cement production. The experimental plan was designed to analyze compressive strength, workability and thermal performance of various CCA blended cements. The data from the experiment indicates that up to 10% CCA replacement could be used in cement production without compromising the structural integrity of OPC. In addition, it was found that the compressive strength and workability of the resulting concrete could be improved when CCA is added to the mixtures. Furthermore, it was shown that the introduction of 10% CCA can lead to significant reduction in thermal conductivity of the mixture.

  14. Strategic Management of Human Capital Development on Employees Performance in Nigeria Cements Sector

    Directory of Open Access Journals (Sweden)

    Ehis Omoluabi

    2013-12-01

    Full Text Available The synopsis of strategic management of human capital development on employees performance in Nigeria cement sector, emphasize the relative roles of strategic management of human capital development in the Nigerian cement sector. The paper discuss number of factors that contributes to the success of Nigerian cement sector; these factors are skills, experiences, qualification of individual employees, ideas etc. The paper further examine that strategic management has helped the development of employees performance in the Nigerian cement sector. The researcher divided the cement sector into zones e.g. Lagos, Ibadan, and Ekiti. This resulted to total population of 750 employees in the cement industry as at the time the research was conducted. The Taro Yamae statistical formula was used to determine the sample size of 511. The researcher made use of primary and secondary source of data collection for the findings. The paper find out that constant training and development of employees has helped the cement sector to do well in their business operation which will help improved quality and innovation with the goal of gaining completive advantage through human resource. That the contribution of HCD can lead to organizational performance and effectively linked to changes in different business environment including micro and macro context.

  15. Characterization of modified calcium-silicate cements exposed to acidic environment

    Energy Technology Data Exchange (ETDEWEB)

    Camilleri, Josette, E-mail: josette.camilleri@um.edu.mt

    2011-01-15

    Portland cement which is used as a binder in concrete in the construction industry has been developed into a biomaterial. It is marketed as mineral trioxide aggregate and is used in dentistry. This material has been reported to be very biocompatible and thus its use has diversified. The extended use of this material has led to developments of newer versions with improved physical properties. The aim of this study was to evaluate the effect of acidic environments found in the oral cavity on fast setting calcium silicate cements with improved physical properties using a combination of techniques. Two fast setting calcium silicate cements (CSA and CFA) and two cement composites (CSAG and CFAG) were assessed by subjecting the materials to lactic acid/sodium lactate buffer gel for a period of 28 days. At weekly intervals the materials were viewed under the tandem scanning confocal microscope (TSM), and scanning electron microscope (SEM). The two prototype cements exhibited changes in their internal chemistry with no changes in surface characteristics. Since the changes observed were mostly sub-surface evaluation of surface characteristics of cement may not be sufficient in the determination of chemical changes occurring. - Research Highlights: {yields} An acidic environment affects modified fast setting calcium silicate-based cements. {yields} No surface changes are observed in acidic environment. {yields} An acidic environment causes sub-surface changes in the material chemistry which are only visible in fractured specimens. {yields} A combination of techniques is necessary in order to evaluate the chemical changes occurring.

  16. Characterization of modified calcium-silicate cements exposed to acidic environment

    International Nuclear Information System (INIS)

    Portland cement which is used as a binder in concrete in the construction industry has been developed into a biomaterial. It is marketed as mineral trioxide aggregate and is used in dentistry. This material has been reported to be very biocompatible and thus its use has diversified. The extended use of this material has led to developments of newer versions with improved physical properties. The aim of this study was to evaluate the effect of acidic environments found in the oral cavity on fast setting calcium silicate cements with improved physical properties using a combination of techniques. Two fast setting calcium silicate cements (CSA and CFA) and two cement composites (CSAG and CFAG) were assessed by subjecting the materials to lactic acid/sodium lactate buffer gel for a period of 28 days. At weekly intervals the materials were viewed under the tandem scanning confocal microscope (TSM), and scanning electron microscope (SEM). The two prototype cements exhibited changes in their internal chemistry with no changes in surface characteristics. Since the changes observed were mostly sub-surface evaluation of surface characteristics of cement may not be sufficient in the determination of chemical changes occurring. - Research Highlights: → An acidic environment affects modified fast setting calcium silicate-based cements. → No surface changes are observed in acidic environment. → An acidic environment causes sub-surface changes in the material chemistry which are only visible in fractured specimens. → A combination of techniques is necessary in order to evaluate the chemical changes occurring.

  17. 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.

  18. Incorporation of the Spinning Wastes in Cement and Mortars

    International Nuclear Information System (INIS)

    The study falls within the scope of the general problem of management of accumulated solid cellulose based wastes originating from textile industry especially those coming from the spinning process. The present investigation aims at studying the wet oxidative degradation technique as a method for treating cellulose-based wastes generated by the textile spinning industries. The resulting treated wastes were incorporated into cement or mortar. The mechanical integrity and the weight change of the final products were evaluated at the end of setting and hardening

  19. Special recipe for cement solidification

    International Nuclear Information System (INIS)

    ABB Atom's MOSS is a compact, mobile system for immobilizing radwaste in cement. Various ''recipes'' have been developed to meet stringent end product requirements. A version of MOSS, described here, was delivered to Borssele last year and has completed two solidification campaigns to date. (author)

  20. Effect of temporary cements on the shear bond strength of luting cements

    Directory of Open Access Journals (Sweden)

    Marco Fiori-Júnior

    2010-02-01

    Full Text Available OBJECTIVE: The purpose of this study was to evaluate, by shear bond strength (SBS testing, the influence of different types of temporary cements on the final cementation using conventional and self-etching resin-based luting cements. Material and Methods: Forty human teeth divided in two halves were assigned to 8 groups (n=10: I and V (no temporary cementation; II and VI: Ca(OH2-based cement; III and VII: zinc oxide (ZO-based cement; IV and VIII: ZO-eugenol (ZOE-based cement. Final cementation was done with RelyX ARC cement (groups I to IV and RelyX Unicem cement (groups V to VIII. Data were analyzed statistically by ANOVA and Tukey's test at 5% significance level. RESULTS: Means were (MPa: I - 3.80 (±1.481; II - 5.24 (±2.297; III - 6.98 (±1.885; IV - 6.54 (±1.459; V - 5.22 (±2.465; VI - 4.48 (±1.705; VII - 6.29 (±2.280; VIII - 2.47 (±2.076. Comparison of the groups that had the same temporary cementation (Groups II and VI; III and VII; IV and VIII showed statistically significant difference (p0.05 for the different luting cements (RelyX TM ARC and RelyX TM Unicem. The groups that had no temporary cementation (Groups I and V did not differ significantly from each other either (p>0.05. CONCLUSION: When temporary cementation was done with ZO- or ZOE-based cements and final cementation was done with RelyX ARC, there was an increase in the SBS compared to the control. In the groups cemented with RelyX Unicem, however, the use of a ZOE-based temporary cement affected negatively the SBS of the luting agent used for final cementation.

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

    International Nuclear Information System (INIS)

    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)

  2. 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

  3. 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.

  4. Effect of irradiation on acrylic cement with special reference to fixation of pathological fractures

    International Nuclear Information System (INIS)

    Self-curing cement is generally used in conjunction with conventional metallic devices. If the acrylic cement was supplemented, the primary goal would be a rigid immobiliztion of the fracture to alleviate the pain; usually, however, the final aim is toward osteosynthesis. During the course of rehabilitation, it is often desirous to supplement the treatment by irradiation. Although the industrial, dental and surgical literature has adequately dealt with many aspects of bone cement; for example, physical and chemical properties in joint replacement, and so on, the effects of irradiation on the acrylic cement have not been previously reported. It is the purpose of this paper to analyze the experimental studies conducted to evaluate the mechanical properties of the polymethylmethacrylate when subjected to irradiation within a maximum range of a therapeutic dose

  5. Analysis by X-Ray images of EVA waste incorporated in Portland Cement

    International Nuclear Information System (INIS)

    The EVA is a copolymer used by Brazilian shoes industries. This material is cut for the manufacture of insoles. This operation generates about 18% of waste. The EVA waste can be reused in incorporation in Portland cement to construction without structural purposes. The aim of this work is to show X-rays images to assessment the space distribution of the wastes in the cement and to evaluate the use of this methodology. Cylindrical specimens were produced according to ABNT - NBR 5738 standards. The volume relation of sand and cement was 3:1, 10% and 30% of waste was incorporated in cement specimens. X-Rays images were obtained of cylindrical specimens in front projection. The images showed that the distribution of the waste is homogeneous, consistent with what was intended in this type of incorporation, which can provide uniformity in test results of compressive strength. (author)

  6. Mesoscale texture of cement hydrates.

    Science.gov (United States)

    Ioannidou, Katerina; Krakowiak, Konrad J; Bauchy, Mathieu; Hoover, Christian G; Masoero, Enrico; Yip, Sidney; Ulm, Franz-Josef; Levitz, Pierre; Pellenq, Roland J-M; Del Gado, Emanuela

    2016-02-23

    Strength and other mechanical properties of cement and concrete rely upon the formation of calcium-silicate-hydrates (C-S-H) during cement hydration. Controlling structure and properties of the C-S-H phase is a challenge, due to the complexity of this hydration product and of the mechanisms that drive its precipitation from the ionic solution upon dissolution of cement grains in water. Departing from traditional models mostly focused on length scales above the micrometer, recent research addressed the molecular structure of C-S-H. However, small-angle neutron scattering, electron-microscopy imaging, and nanoindentation experiments suggest that its mesoscale organization, extending over hundreds of nanometers, may be more important. Here we unveil the C-S-H mesoscale texture, a crucial step to connect the fundamental scales to the macroscale of engineering properties. We use simulations that combine information of the nanoscale building units of C-S-H and their effective interactions, obtained from atomistic simulations and experiments, into a statistical physics framework for aggregating nanoparticles. We compute small-angle scattering intensities, pore size distributions, specific surface area, local densities, indentation modulus, and hardness of the material, providing quantitative understanding of different experimental investigations. Our results provide insight into how the heterogeneities developed during the early stages of hydration persist in the structure of C-S-H and impact the mechanical performance of the hardened cement paste. Unraveling such links in cement hydrates can be groundbreaking and controlling them can be the key to smarter mix designs of cementitious materials. PMID:26858450

  7. Leaching of tritium from a cement composite

    International Nuclear Information System (INIS)

    Leaching of tritium from cement composites into an aqueous phase has been studied to evaluate the safety of incorporation of the tritiated liquid waste into cement. Leaching tests were performed by the method recommended by the International Atomic Energy Agency. The Leaching fraction was measured as functions of waste-cement ratio (Wa/C), temperature of leachant and curing time. The tritium leachability of cement in the long term test follows the order: alumina cement portland cement slag cement. The fraction of tritium leached increases with increasing Wa/C and temperature and decreasing curing period. A deionized water as a leachant gives a slightly higher leachability than synthetic sea water. The amount leached of tritium from a 200 l drum size specimen was estimated on the basis of the above results. (author)

  8. 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

  9. 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

  10. Chloride adsorption by calcined layered double hydroxides in hardened Portland cement paste

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Seyoon [School of Engineering, Kings College, University of Aberdeen, Aberdeen AB24 3UE (United Kingdom); Moon, Juhyuk, E-mail: juhyuk.moon@stonybrook.edu [Civil Engineering Program, Department of Mechanical Engineering, State University of New York at Stony Brook, New York 11794 (United States); Bae, Sungchul [Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720 (United States); Duan, Xiaonan [Department of Materials Science and Engineering, Cornell University, Ithaca, NY 14853 (United States); Giannelis, Emmanuel P. [Department of Materials Science and Engineering, Cornell University, Ithaca, NY 14853 (United States); Center for Refining and Petrochemicals, The Research Institute, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Monteiro, Paulo M. [Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720 (United States)

    2014-06-01

    This study investigated the feasibility of using calcined layered double hydroxides (CLDHs) to prevent chloride-induced deterioration in reinforced concrete. CLDHs not only adsorbed chloride ions in aqueous solution with a memory effect but also had a much higher binding capacity than the original layered double hydroxides (LDHs) in the cement matrix. We investigated this adsorption in hardened cement paste in batch cultures to determine adsorption isotherms. The measured and theoretical binding capacities (153 mg g{sup −1} and 257 mg g{sup −1}, respectively) of the CLDHs were comparable to the theoretical capacity of Friedel's salt (2 mol mol{sup −1} or 121 mg g{sup −1}), which belongs to the LDH family among cementitious phases. We simulated chloride adsorption by CLDHs through the cement matrix using the Fickian model and compared the simulation result to the X-ray fluorescence (XRF) chlorine map. Based on our results, it is proposed that the adsorption process is governed by the chloride transport through the cement matrix; this process differs from that in an aqueous solution. X-ray diffraction (XRD) analysis showed that the CLDH rebuilds the layered structure in a cementitious environment, thereby demonstrating the feasibility of applying CLDHs to the cement and concrete industries. - Highlights: • We examine the adsorption equilibrium and kinetics of CLDH in the hydrated cement. • CLDH capacity to bind chloride ions in the hydrated cement paste is determined. • We model chloride adsorption by CLDH through the cement matrix. • CLDH reforms the layered structure with ion adsorption in the cement matrix.

  11. Chloride adsorption by calcined layered double hydroxides in hardened Portland cement paste

    International Nuclear Information System (INIS)

    This study investigated the feasibility of using calcined layered double hydroxides (CLDHs) to prevent chloride-induced deterioration in reinforced concrete. CLDHs not only adsorbed chloride ions in aqueous solution with a memory effect but also had a much higher binding capacity than the original layered double hydroxides (LDHs) in the cement matrix. We investigated this adsorption in hardened cement paste in batch cultures to determine adsorption isotherms. The measured and theoretical binding capacities (153 mg g−1 and 257 mg g−1, respectively) of the CLDHs were comparable to the theoretical capacity of Friedel's salt (2 mol mol−1 or 121 mg g−1), which belongs to the LDH family among cementitious phases. We simulated chloride adsorption by CLDHs through the cement matrix using the Fickian model and compared the simulation result to the X-ray fluorescence (XRF) chlorine map. Based on our results, it is proposed that the adsorption process is governed by the chloride transport through the cement matrix; this process differs from that in an aqueous solution. X-ray diffraction (XRD) analysis showed that the CLDH rebuilds the layered structure in a cementitious environment, thereby demonstrating the feasibility of applying CLDHs to the cement and concrete industries. - Highlights: • We examine the adsorption equilibrium and kinetics of CLDH in the hydrated cement. • CLDH capacity to bind chloride ions in the hydrated cement paste is determined. • We model chloride adsorption by CLDH through the cement matrix. • CLDH reforms the layered structure with ion adsorption in the cement matrix

  12. Determination of Vanadium, Tin and Mercury in Atmospheric Particulate Matter and Cement Dust Samples by Direct Current Plasma Atomic Emission Spectrometry.

    Science.gov (United States)

    Hindy, Kamal T.; And Others

    1992-01-01

    An atmospheric pollution study applies direct current plasma atomic emission spectrometry (DCP-AES) to samples of total suspended particulate matter collected in two industrial areas and one residential area, and cement dust collected near major cement factories. These samples were analyzed for vanadium, tin, and mercury. The results indicate the…

  13. Tendencias y cambio del clima del valle del Mantaro mediante los análisis de índices de Precipitación Efectiva y Temperatura Eficiente

    OpenAIRE

    Jacinto Arroyo Aliaga

    2011-01-01

    Objetivos: La investigación fue para evaluar los cambios y tendencias del clima del valle del Mantaro en función del análisis de sus índices de temperatura eficiente y precipitación efectiva a partir de los valores totales mensuales de precipitación y valores medios mensuales de temperatura, medidos desde el año 1921 hasta el año 2010, para comparar la tendencia de los movimientos seculares con la teoría del calentamiento climático global. Métodos: Para encontrar las tendencias de las precipi...

  14. Combustion of solid alternative fuels in the cement kiln burner

    DEFF Research Database (Denmark)

    Nørskov, Linda Kaare

    In the cement industry there is an increasing environmental and financial motivation for substituting conventional fossil fuels with alternative fuels, being biomass or waste derived fuels. However, the introduction of alternative fuels may influence emissions, cement product quality, process...... conditions relevant to suspension fired combustion. An experimental combustion reactor for simulating suspension fired combustion of large, single particles is established and experiments are performed to investigate conversion pathways, ignition, devolatilisation, and char oxidation times of pine wood, and.......e. grinding and drying, is insufficient to ensure the dried sewage sludge to be converted within the available time in suspension, however a partial particle downsizing without drying can be allowed for refuse derived fuel firing. By increasing the entrainment rate of secondary air, the primary air percentage...

  15. Tendencias de mortalidad por cánceres atribuibles al tabaco en México

    Directory of Open Access Journals (Sweden)

    Tovar-Guzmán Víctor José

    2002-01-01

    Full Text Available Objetivo. Describir la tendencia de la mortalidad por cáncer atribuible al consumo de tabaco, particularmente neoplasias del pulmón, en México, durante el periodo 1980-1997. Material y métodos. Se hizo un análisis de tendencias de mortalidad para cada tipo de cáncer asociado con el tabaco, según la Clasificación Internacional de Enfermedades. Las tasas cruda y ajustada de mortalidad fueron estimadas en términos de edad, género, causa básica de la muerte y año, entre 1980 y 1997. Se estimó la razón de género y proporción relativa para los casos que estaban en el grupo de edad entre 35 y 64 años y para toda la población estudiada. Como denominador se utilizaron las proyecciones por edad calculadas por el Consejo Nacional de Población (1970-2010. Resultados. La razón de género para las tasas de mortalidad por cáncer de laringe, esófago, cavidad oral y faringe fue de 2.10:1.00 (hombre: mujer. La razón de género para el cáncer de laringe es enorme: 4.21: 1.00, probablemente debida a la mayor prevalencia de hombres fumadores de tabaco. La proporción relativa estimada, usando la mortalidad total debida a tumores malignos, entre 1980 y 1997 fue la siguiente: cáncer de pulmón 12.31%, laringe 1.71%, esófago 1.55% y cavidad oral/faringe 1.49%. El antecedente de tabaquismo tiene correlación con la tendencia de la tasa de mortalidad por cáncer del pulmón (Beta: 0.910, IC 95%: 1.097-1.797; R² 0.827. Para los grupos sociales mas pobres, por entidad federativa, la correlación está invertida (Beta: -0.510, IC 95%: -0.170, -0.039, R²: 0.260. Conclusiones. En México, la mejoría en el diagnóstico, la transición demográfica y el incremento del consumo de tabaco son, probablemente, los principales factores a los que se atribuye la tasa de mortalidad por cáncer. No obstante, otras variables asociadas con el estilo de vida, como urbanización, actividad física, ingesta de carotenoides y otros componentes dietéticos y t

  16. Cement og politik

    DEFF Research Database (Denmark)

    Lund, Joachim

    2012-01-01

    Gunnar Larsen (1902-1973) was raised to be an engineer, a businessman, and a successor to the throne of F.L. Smidth & Co., then and now one of Denmark’s leading industrial corporations, which his father had co-founded in the 1880s. However, he is primarily known for his short-lived political career...... intended to prove the Danish government’s willingness and ability to work closely with the NS regime. As the war drew on and the Allies slowly gained the upper hand, Larsen’s activism made him increasingly unpopular, and after the government’s withdrawal in August 1943, he became a primary target of......, he had no future in Danish business life. He was ousted from F.L. Smidth & Co. and later emigrated to Ireland. Gunnar Larsen’s history as a succesful business leader who failed as a politician as well as his postwar fate not only testify to the change in public opinion during the war but also to the...

  17. Factors Influencing Energy Intensity in Four Chinese Industries

    OpenAIRE

    Fisher-Vanden, Karen; Hu, Yong; Jefferson, Gary; Rock, Michael; Toman, Michael

    2013-01-01

    Energy intensity has declined significantly in four Chinese industries -- pulp and paper; cement; iron and steel; and aluminum. While previous studies have identified technological change within an industry to be an important influence on energy intensity, few have examined how industry-specific policies and market factors also affect industry-level intensity. This paper employs unique fi...

  18. Carbonation on ternary cement systems

    OpenAIRE

    Martínez Ramírez, Sagrario; Fernández Carrasco, Lucía

    2012-01-01

    The main hydration reaction product in the ternary system fly ash, calcium sulphate and calcium aluminate cement (40/20/40) at 20°C is a hydrated calcium sulfoaluminate compound, an AFt phase slightly different from “traditional ettringite”. The carbonation of ettringite develops gypsum but in this case rapidcreekite is formed. For the first time it has been observed that carbonation of the mentioned calcium sulfoaluminate compound (AFt), an hydrated calcium sulphate carbonated phase (Ca2(SO4...

  19. WHITE CEMENT IN SUSTAINABLE DEVELOPMENT

    OpenAIRE

    Y.C.P RAMANA BABU; B.SAI DOONDI; N. M .V .VAMSI KRISHNA; K.Prasanthi

    2013-01-01

    India is one among the fast developing countries in the world in the areas of Infrastructure. Now a day, Carbon monoxide (CO) and carbon dioxide (CO2) are the temporary atmospheric pollutants in the environment chiefly emitted from the fuel burning vehicles and street lights which lead to global warming and pose a major threat tothe survival and sustainable development. This paper deals with the principal purpose of use of white cement in pavement design which will take care of the Green hous...

  20. ROTARY SCREW SYSTEMS IN CEMENT

    OpenAIRE

    Taratuta V. D.; Belokur K. A.; Serga G. V.

    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...

  1. Eco-friendly Development Of Industry

    International Nuclear Information System (INIS)

    This book reports eco-friendly development of industry, which has summary on bring up the issue and research way and system of research. It deals with current state of affairs on eco-friendly development of industry and the case of developed countries such as necessity and meaning of eco-friendly development industry, prospect and change of the tendency, environmental issue by field in Korea like the steel industry, nonferrous metal industry, auto industry, and cement industry and general policy for eco-friendly development of industry.

  2. The comparison analysis of total factor productivity and eco-efficiency in China's cement manufactures

    International Nuclear Information System (INIS)

    This paper mainly compares total factor productivity and eco-efficiency in China's cement manufactures from 2005 to 2010. First, we evaluate total factor productivity and eco-efficiency of China's cement manufactures through distance function and directional slack-based measure (DSBM) respectively. Furthermore, we also explore the difference of total factor productivity and eco-efficiency. Last, we investigate the determinants of Malmquist, Mamlquist–Luenberger of China's cement manufactures through random-effect Tobit and bootstrap truncated econometric methods. We find that there are some gaps between Malmquist and Mamlquist–Luenberger of China's cement manufactures. Per labor cement industry value has U-shape relationship with both Malmquist and Malmquist–Luenberger. It is necessary to adopt advanced technology to reduce pollutant emissions. -- Highlights: •Eco-efficiency of cement manufactures is evaluated through slack-based measure. •Eco-efficiency of China's cement manufactures has biases with total factor productivity. •Environmental Kuznets curve is existed for China's cement manufactures

  3. WHITE CEMENT IN SUSTAINABLE DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    Y.C.P RAMANA BABU

    2013-04-01

    Full Text Available India is one among the fast developing countries in the world in the areas of Infrastructure. Now a day, Carbon monoxide (CO and carbon dioxide (CO2 are the temporary atmospheric pollutants in the environment chiefly emitted from the fuel burning vehicles and street lights which lead to global warming and pose a major threat tothe survival and sustainable development. This paper deals with the principal purpose of use of white cement in pavement design which will take care of the Green house gases (i.e., CO and CO2 and also saves lot of money in the long run process. A small amount of these gases in environment can cause major problems over time. Use of white cement in composite pavement design where there is heavy traffic loads are acting as well as number of vehicles are more such as junctions, bus stops, check posts etc., can perform better and acts asenvironment friendly. Its light colour reflects more than bituminous pavement so that it can be easily identified and avoid accidents to some extent. White cement helps to lower the average bus stop, junction temperature providing comfort to the people because it has high solar reflectance there by reducing “urban heat island” effect. In addition to this it has some more advantages which increase the sustainability, durability and workability of the pavements.

  4. Experimental study on improving cement quality with oxygen- enriched combustion technology

    Science.gov (United States)

    Liu, Y. Q.; Zhang, A. M.; Qing, S.; Li, F. S.; Yang, S. P.; Yang, Z. F.

    2015-12-01

    With the intensification of the global energy crisis, the production cost of enterprises is continuously increasing because of the rising fuel prices and high requirements for environmental protection. As result, energy savings and environmental protection are vital considerations for a variety of enterprises. As a practical energy-saving technology, oxygen- enriched combustion has played a major role in energy saving and emissions reduction as its application in industrial furnaces has been popularized in recent years. This experiment was conducted in a cement rotary kiln with a capacity of 4000 t/d in a factory in China. Based on measured data in the oxygen-enriched combustion experiment, we determined the patterns of variation in the main parameters of the cement rotary kiln under oxygen-enriched production conditions. The results provide important theoretical and practical base for the cement building materials industry in energy saving and emissions reduction.

  5. Scanning electron microscopy analysis of dental cements

    Directory of Open Access Journals (Sweden)

    Radosavljević Radivoje D.

    2009-01-01

    Full Text Available The aim of this study was to compare in vitro the characteristics of different types of luting cements (zinc phosphate, glass-ionomer and resin based composite cement using scanning electron microscopy (SEM analysis and microleakage for the quality range of materials. Dental cements were mixed in accordance with the manufacturer's instructions and formed with posts in dental root canals of extracted teeth. The quality of cement was determined by SEM observation on horizontal sectioned roots with fixed posts according to specific pore and marginal gap diameter. The microleakage was measured on specimens immersed in Lofler (methylene blue solution. The mean values of the maximal diameter of pores, marginal gaps and microleakage of conventional cements are remarkably larger in comparison with composite luting agents. In conclusion, the quality and efficiency of composite luting agents in comparison with conventional cements are more successful in protecting the interior of tooth from penetration of oral fluids, bacteria and bacterial toxins into unprotected dentine.

  6. Influence of calcium sulfoaluminate cement on the pullout performance of reinforcing fibers: An evaluation of the micro-mechanical behavior

    Science.gov (United States)

    Jewell, Robert Benjamin

    The objective of this research was to determine the influence of calcium sulfoaluminate (CSA) cement on reinforcing fibers by evaluating the fiber pullout behavior, and bonding characteristics, of a single fiber embedded in a cementitious paste matrix. Four types of fibers commonly used in industry were evaluated: 1) Polyvinyl alcohol; 2) Polypropylene; 3) Coated Steel; and 4) Plain Steel. Upward trends in energy costs and potential greenhouse gas regulations favor an increased use of construction materials that require lower energy and lower CO2 emissions to fabricate, such as CSA cement, as opposed to the production of ordinary portland cement (OPC), which is more energy intensive and produces more CO2 emissions. However, widespread use of CSA cement requires a more in-depth understanding of the engineering characteristics that govern its performance, including interaction with reinforcing fibers. The overarching objective of this research was to provide the engineering base needed for the utilization of reinforcing fibers in CSA cement-based construction materials. The aims of the research were (1) to develop an ettringite-rich calcium sulfoaluminate cement, and (2) evaluate the pullout characteristics of reinforcing fibers embedded in a CSA-cement matrix. Key elements of the strategy included (1) Compare the performance of a laboratory-fabricated CSA cement to a commercial CSA cement and OPC, (2) Evaluate the peak load, and toughness of reinforcing fibers in CSA cement and OPC, (3) Evaluate the debonding-energy density and multiple-cracking behavior of fibers in CSA cement and OPC, and (4) Evaluate the shear bond strength of reinforcing fibers in CSA cement and OPC. Based on the findings of this PhD dissertation, calcium sulfoaluminate cement has a significant influence on the characteristics and behavior of embedded reinforcing fibers. An important factor contributing to the bond strength between fiber and matrix was the ability to transfer interfacial

  7. The element composition determination of cement raw meal by neutron-induced prompt gamma-ray analysis

    International Nuclear Information System (INIS)

    Neutron-induced prompt gamma-ray analysis (NIPGA) is a new method which suit the modernization of cement industry. It can analyze several elements at the same time. The analysis of a kind of cement sample can be completed in 15 minutes, which is faster than conventional chemical analysis. The error of CaO, SiO2, Fe2O3 and Al2O3 of the cement by NIPGA comparing with the chemical analysis are less than 0.60%, 0.40%, 0.40% and 0.40%, respectively. (authors)

  8. Premixed calcium silicate cement for endodontic applications

    OpenAIRE

    Persson, Cecilia; Engqvist, Håkan

    2011-01-01

    Calcium silicate-based materials (also called MTA) are increasingly being used in endodontic applications. However, the handling properties of MTA are not optimal when it comes to injectability and cohesion. Premixing the cements using glycerol avoids these issues. However, there is a lack of data on the effect of common cement variables on important properties of premixed cements for endodontic applications. In this study, the effects of liquid-to-powder ratio, amount of radiopacifier and am...

  9. Water dynamics in glass ionomer cements

    Science.gov (United States)

    Berg, M. C.; Jacobsen, J.; Momsen, N. C. R.; Benetti, A. R.; Telling, M. T. F.; Seydel, T.; Bordallo, H. N.

    2016-07-01

    Glass ionomer cements (GIC) are an alternative for preventive dentistry. However, these dental cements are complex systems where important motions related to the different states of the hydrogen atoms evolve in a confined porous structure. In this paper, we studied the water dynamics of two different liquids used to prepare either conventional or resin-modified glass ionomer cement. By combining thermal analysis with neutron scattering data we were able to relate the water structure in the liquids to the materials properties.

  10. Magnitud y Tendencia del Suicidio en los Cantones de Costa Rica: 1980 - 1994

    Directory of Open Access Journals (Sweden)

    Damaris Granados Bloise

    1998-07-01

    Full Text Available En dos anteriores entregas de este estudio, la primera publicada en el número anterior de esta Revista (1 y la segunda en este mismo número, se analizó, para Costa Rica como un todo y por provincias, respectivamente, la magnitud, estructura por edad y sexo, y tendencia del suicidio en el período 1980-94. En esta tercera entrega se presentan los resultados por cantones. (2 (3 (4. En la totalidad de los quince años que abarca el período 1980-94, se registraron en Costa Rica 2.015 muertes por suicidio, siendo la tasa promedio anual de mortalidad por esa causa, para el país, de 4.8 defunciones por cada 100.000 habitantes. En orden de magnitud descendente, son cantones de la región de Los Santos, Provincia de San José, los que ocupan los tres primeros lugares: Dota (13.4, Tarrazú (12.1 y León Cortés (10.9; junto con Alvarado (10.4 en Cartago, sobrepasan los 10 suicidios promedio anual por cada 100.000 habitantes.

  11. TENDENCIAS DEL NEGOCIO DE LAS TELEVISORAS Y PRODUCTORAS COMERCIALES EN EL ESTADO ZULIA

    Directory of Open Access Journals (Sweden)

    Rocío Belandria Cerdeira

    2005-07-01

    Full Text Available Este artículo presenta los resultados de un estudio de campo cuyo objetivo fue identificar las tendencias del negocio en las televisoras y productoras comerciales de la región zuliana. El estudio es de carácter exploratorio, realizado a partir de un trabajo de campo. Se aplicó una entrevista de preguntas abiertas a una muestra no probabilistica intencionada de cuatro televisoras y tres productoras de televisión comerciales de la región. La metodología es cualitativa por lo que el interés está dirigido a la descripción verbal que los informantes proporcionan de los hechos más que su medición. Los resultados arrojados indican que: 1 el negocio de las televisoras se afianza mayormente en la venta de espacios; 2 para las productoras el negocio en crear, producir y atender las necesidades del cliente, 3 el negocio está apalancado en el mercadeo y utiliza variadas estrategias direccionadas en forma descendente desde la gerencia, 4 se arrojan ganancias; y 5 el sector aparece en pleno crecimiento a pesar de la crisis del país.

  12. Tendencias en los sistemas de indización automática. Estudio evolutivo

    Directory of Open Access Journals (Sweden)

    Gil Leiva, Isidoro

    1996-09-01

    Full Text Available In this article, we present the evolution of automatic indexing and computer-assisted indexing, from the original works, about 1960 up to the present. The systems described have been divided in four sections: systems that use non linguistic methods, systems that use linguistic means, commercialized systems and last trends based upon multimedia. A wide bibliographic review of forty years of automatic indexing systems has been done. Finally, the conclusions are shown.

    Se presenta la evolución de la indización automática y asistida por ordenador desde que se inician las primeras investigaciones, a finales de los años cincuenta, hasta la actualidad. Los sistemas descritos se han dividido en cuatro apartados: aquéllos que utilizan métodos no lingüísticos, los que emplean criterios lingüísticos, los sistemas comercializados, y las últimas tendencias en indización automática de información multimedia. Para el estudio de esta evolución se realiza una amplia revisión bibliográfica que abarca cuatro décadas de indagaciones que han dado lugar a numerosos proyectos de indización automática o asistida por ordenador, de los cuales se examinan más de veinticinco. Finalmente se muestran las conclusiones.

  13. Análisis de tendencias de heliofanía efectiva en Argentina

    Directory of Open Access Journals (Sweden)

    Hugo Grossi Gallegos

    2007-12-01

    Full Text Available Se presentan resultados del análisis estadístico de series temporales de promedios anuales de heliofanía efectiva (horas de brillo solar registrados en estaciones de Argentina, que compensan la insuficiencia de datos de irradiación solar y permiten estudiar tendencias relacionadas con el Cambio Climático Global. Se aplicó un estudio previo de consistencia teniendo en cuenta el error de medición, con la aplicación del test de Mann-Kendall y se discuten los resultados obtenidos. Aparecen algunas estaciones en las que los promedios anuales de la heliofanía efectiva decrecen significativamente, agrupándose fundamentalmente en una zona ubicada al noreste de la Pampa Húmeda y al sur de la Mesopotamia.Results of the statistic analysis of time series of annual averages of hours of solar brightness registered in stations of Argentina are presented; these values compensate the insufficiency of data of solar irradiation and allow studying tendencies related to the Global Climatic Change. The measurement error was taken into account in a previous study of consistency, temporal analysis is made with the application of the test of Mann-Kendall and the obtained results are discussed. They appear some stations in which the annual averages of hours of solar brightness decrease significantly, grouping itself essentially in a zone located to the northeast of Humid Pampas and to the south of the Mesopotamia.

  14. Nuevas tendencias en la historiografía española

    Directory of Open Access Journals (Sweden)

    SanMartin, Israel

    2007-12-01

    Full Text Available The article is framed in which some historians have denominated “immediate historiography” (it consists of reflecting on the history of the historiography developed on the time of the historian. The investigation in the describes, analyzes and explains the evolution of the recent Spanish historiography. Thus, the author will studie the characteristics of the recent Spanish historiography, the last historiography Spanish tendencies, and will deepen one of them; History to Debate, that will serve as waiting room for the conclusions.

    El artículo se enmarca en lo que algunos historiadores han denominado “historiografía inmediata”, que consiste en reflexionar sobre la historia de la historiografía que se está desarrollando a la par del propio historiador. La investigación describe, analiza y explica la evolución de la historiografía española reciente en los últimos a��os. Así, el autor tratará en su primer apartado las características de la historiografía española reciente, después identificará las últimas tendencias historiográficas españolas, para terminar con la profundización en una de ellas; Historia a Debate, que servirá de antesala para las conclusiones.

  15. Comer por aburrimiento: relación entre tendencia al aburrimiento y estilos de ingesta en población general.

    OpenAIRE

    López Montoyo, Alba; Cebolla i Martí, Ausiàs Josep

    2016-01-01

    Antecedentes: Por comer emocional se entiende la tendencia a comer con el objetivo de regular emociones negativas, entre ellas el aburrimiento sin atender a las necesidades de hambre. El objetivo del presente estudio es examinar las relaciones existentes entre la tendencia al aburrimiento y los estilos de ingesta y la regulación emocional. Método: La muestra consiste en 123 personas adultas. Las medidas utilizadas incluyen los estilos de ingesta medidos a través del Dutch Eatin...

  16. Tendencia poblacional en tres colonias de gaviota patiamarilla Larus michahellis Naumann, 1840 en Gipuzkoa: 2000-2013

    Directory of Open Access Journals (Sweden)

    Arizaga, J., Aldalur, A., Herrero, A.

    2014-01-01

    Full Text Available En este trabajo se analiza la evolución de la población de gaviota patiamarilla Larus michahellis Naumann, 1840 en Gipuzkoa, con el fin de determinar si esta población ha aumentado o no durante los últimos años. Se desarrolla un modelo de crecimiento poblacional a partir de datos de censos llevados a cabo en tres colonias de referencia (Ulia-Faro, Santa Clara y Geteria, para el periodo 2000-2013, mediante el programa TRIM. La población estudiada ha pasado de 354 parejas (pp. en 2000 a 299 pp. en 2013. Observamos un ajuste malo de nuestros modelos (modelo de crecimiento nulo y modelo que estima un cambio log-lineal de la población a los datos que, no obstante, tanto para todas las colonias como para cada una de las colonias por separado, el modelo que estima un cambio log-lineal se ajusta mejor a los datos. Globalmente, la tendencia de las colonias es incierta (estable. Por colonias, las tendencias son dispares, lo cual indicaría dinámicas distintas. En el caso de Ulia la colonia disminuye durante el periodo de estudio, mientras que en Santa Clara la colonia es estable, y en Getaria aumenta. Globalmente, durante el periodo de estudio, el descenso de Ulia se habría compensado con las tendencias observadas en las otras dos colonias.

  17. DSC and TG Analysis of a Blended Binder Based on Waste Ceramic Powder and Portland Cement

    Science.gov (United States)

    Pavlík, Zbyšek; Trník, Anton; Kulovaná, Tereza; Scheinherrová, Lenka; Rahhal, Viviana; Irassar, Edgardo; Černý, Robert

    2016-03-01

    Cement industry belongs to the business sectors characteristic by high energy consumption and high {CO}2 generation. Therefore, any replacement of cement in concrete by waste materials can lead to immediate environmental benefits. In this paper, a possible use of waste ceramic powder in blended binders is studied. At first, the chemical composition of Portland cement and ceramic powder is analyzed using the X-ray fluorescence method. Then, thermal and mechanical characterization of hydrated blended binders containing up to 24 % ceramic is carried out within the time period of 2 days to 28 days. The differential scanning calorimetry and thermogravimetry measurements are performed in the temperature range of 25°C to 1000°C in an argon atmosphere. The measurement of compressive strength is done according to the European standards for cement mortars. The thermal analysis results in the identification of temperature and quantification of enthalpy and mass changes related to the liberation of physically bound water, calcium-silicate-hydrates dehydration and portlandite, vaterite and calcite decomposition. The portlandite content is found to decrease with time for all blends which provides the evidence of the pozzolanic activity of ceramic powder even within the limited monitoring time of 28 days. Taking into account the favorable results obtained in the measurement of compressive strength, it can be concluded that the applied waste ceramic powder can be successfully used as a supplementary cementing material to Portland cement in an amount of up to 24 mass%.

  18. 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.

  19. AIR POLLUTION CONTROL THROUGH KILN RECYCLING BY-PASS DUST IN A CEMENT FACTORY

    Directory of Open Access Journals (Sweden)

    F. Mohsenzadeh, J. Nouri, A. Ranjbar, M. Mohammadian Fazli, A. A. Babaie

    2006-01-01

    Full Text Available Air pollution is a major problem in the industrial areas. Cement dust is one of the important environmental pollutants. In this study the possibility of dust recycling especially kiln dust which has significant importance regarding air pollution in the cement plant, was examined. Tehran cement factory is one of the most important Iranian factories which is located in Tehran. This factory produces high volume of pollutants that are released to in environment. The possibility of reusing of kiln by pass returned dust has been examined in this factory. Different percentages of kiln by-pass dust of this factory were added to products and outcomes of its presence in parameters such as chemical compound, granulation, primary and final catch time, volume expansion, consumed water and resistance of mortar were surveyed. The result indicated that by adding the amounts of 3-8 dust the mortar resistance increase, but adding more than 15%, the mortar resistance has been decreased. Survey in consumed water proved that adding dust to cement, the trend for consuming water is decreased. After dust addition dust, primary and final catch time were compared in different samples and data which showed decrease in dust added samples. Cements with dust added showed increase in auto clave expansion. Overally, results proved that, the best percentage rate of dust addition to the cement was 15%.

  20. Retention of Root Canal Posts: Effect of Cement Film Thickness, Luting Cement, and Post Pretreatment.

    Science.gov (United States)

    Sahafi, A; Benetti, A R; Flury, S; Peutzfeldt, A

    2015-01-01

    The aim of this study was to investigate the effect of the cement film thickness of a zinc phosphate or a resin cement on retention of untreated and pretreated root canal posts. Prefabricated zirconia posts (CosmoPost: 1.4 mm) and two types of luting cements (a zinc phosphate cement [DeTrey Zinc] and a self-etch adhesive resin cement [Panavia F2.0]) were used. After removal of the crowns of 360 extracted premolars, canines, or incisors, the root canals were prepared with a parallel-sided drill system to three different final diameters. Half the posts did not receive any pretreatment. The other half received tribochemical silicate coating according to the manufacturer's instructions. Posts were then luted in the prepared root canals (n=30 per group). Following water storage at 37°C for seven days, retention of the posts was determined by the pull-out method. Irrespective of the luting cement, pretreatment with tribochemical silicate coating significantly increased retention of the posts. Increased cement film thickness resulted in decreased retention of untreated posts and of pretreated posts luted with zinc phosphate cement. Increased cement film thickness had no influence on retention of pretreated posts luted with resin cement. Thus, retention of the posts was influenced by the type of luting cement, by the cement film thickness, and by the post pretreatment. PMID:25764045

  1. The influence of ultrasound on removal of prefabricated metal post cemented with different resin cements

    Directory of Open Access Journals (Sweden)

    Atiyeh Feiz

    2013-01-01

    Conclusion: Ultrasonic energy did not decrease the retention of posts cemented with Panavia or Maxcem Elite cements. Furthermore, it seems that there is no significant difference between removal force of self-etch (Panavia and the self-etch self-adhesive (Maxcem Elite resin cements.

  2. Immobilisation of radwaste in cement based matrices

    International Nuclear Information System (INIS)

    The solubilities and influence on cement pH are reported for calcium aluminate and aluminosulphate hydrates. The solubility of Ca(OH)2 is reported to 700 bars. Polymerization of C-S-H is investigated by NMR. Specific interactions of U6+ and iodine (I-, IO3-) with cement components are described. The impact of radiation on cements and the influence of higher temperature are documented. The role of dissolved Ca and CO2 in groundwaters as dissolution media for cements are reported. (author)

  3. Acoustic evaluation of cementing quality using obliquely incident ultrasonic signals

    Institute of Scientific and Technical Information of China (English)

    Duan Wen-Xing; Qiao Wen-Xiao; Che Xiao-Hua; Xie Hui

    2014-01-01

    Ultrasonic cement bond logging is a widely used method for evaluating cementing quality. Conventional ultrasonic cement bond logging uses vertical incidence and cannot accurately evaluate lightweight cement bonding. Oblique incidence is a new technology for evaluating cement quality with improved accuracy for lightweight cements. In this study, we simulated models of acoustic impedance of cement and cementing quality using ultrasonic oblique incidence, and we obtained the relation between cementing quality, acoustic impedance of cement, and the acoustic attenuation coeffi cient of the A0-mode and S0-mode Lamb waves. Then, we simulated models of different cement thickness and we obtained the relation between cement thickness and the time difference of the arrival between the A0 and A0′ modes.

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

    Science.gov (United States)

    Sakulich, Aaron Richard

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

  5. THE USE OF SISAL FIBRE AS REINFORCEMENT IN CEMENT BASED COMPOSITES

    Directory of Open Access Journals (Sweden)

    Romildo Dias Tolêdo Filho

    1999-08-01

    Full Text Available ABSTRACT The inclusion of fibre reinforcement in concrete, mortar and cement paste can enhance many of the engineering properties of the basic materials, such as fracture toughness, flexural strength and resistance to fatigue, impact, thermal shock and spalling. In recent years, a great deal of interest has been created worldwide on the potential applications of natural fibre reinforced, cement based composites. Investigations have been carried out in many countries on various mechanical properties, physical performance and durability of cement based matrices reinforced with naturally occurring fibres including sisal, coconut, jute, bamboo and wood fibres. These fibres have always been considered promising as reinforcement of cement based matrices because of their availability, low cost and low consumption of energy. In this review, the general properties of the composites are described in relation to fibre content, length, strength and stiffness. A chronological development of sisal fibre reinforced, cement based matrices is reported and experimental data are provided to illustrate the performance of sisal fibre reinforced cement composites. A brief description on the use of these composite materials as building products has been included. The influence of sisal fibres on the development of plastic shrinkage in the pre-hardened state, on tensile, compressive and bending strength in the hardened state of mortar mixes is discussed. Creep and drying shrinkage of the composites and the durability of natural fibres in cement based matrices are of particular interest and are also highlighted. The results show that the composites reinforced with sisal fibres are reliable materials to be used in practice for the production of structural elements to be used in rural and civil construction. This material could be a substitute asbestos-cement composite, which is a serious hazard to human and animal health and is prohibited in industrialized countries. The

  6. Nucleonic guages in Philippine industry: current applications

    International Nuclear Information System (INIS)

    Nucleonic gauges have been used in Philippine industries for more than thirty years. There are now close to 500 units being used to determine and/or control level, density, concentration, weight and other parameters. Gauges are found in the food, cement, mineral processing, steel, paper, cigarette, plastic and construction industries. (author)

  7. Design and manufacture of Portland cement Application of statistical analysis

    OpenAIRE

    Svinning, Ketil

    2011-01-01

    The purpose of the work is to enable design and manufacture of cement with emphasis on the quality and the properties of cement. Data used in the design and manufacture were collected from predictions of properties and characteristics of cement. The properties of cement were predicted from its characteristics and from the production conditions in cement kiln and mill. The cement characteristics were in some investigations predicted from the production conditions. The design was based on sensi...

  8. Partial Replacement of Cement with Marble Dust Powder

    Directory of Open Access Journals (Sweden)

    Mr. Ranjan Kumar

    2015-08-01

    Full Text Available The waste generated from the industries cause environmental problems. Hence the reuse of this waste material can be emphasized. MarbleDust Powder (MDP is a developing composite materialthatwillallow the concrèteindustry to optimisemateriel use, generateeconomicbenefits and build structures thatwillstrong, durable and sensitive to environnement. MDP is by-product obtained during the quarrying process from the parent marble rock; which contains high calcium oxide content of more than 50%. The potential use of MDP can be an ideal choice for substituting in a cementitious binder as the reactivity efficiency increases due to the presence of lime. In this research work, the waste MDP passing through 90 microns,has used for investigating of hardened concrete properties. Furthermore, the effect of different percentage replacement of MDP on the compressive strength, splitting tensile strength (indirect tensile strength&flexural strength has been observed. Inthis experimental study, the effect of MDP in concrete on strength ispresented. Five concrete mixtures containing 0%, 5%, 10%, and 20% MDP as cement replacement by weightbasis has been prepared. Water/cement ratio (0.43 was kept constant, in all the concretemixes. Compressive strength, split tensile strength & flexural strength of the concrete mixtures has been obtainedat 7 and 28 days. The results of the laboratory work showed thatreplacement of cement with MDP increase, upto 10% for compressive strength,&upto 15% for split tensilestrength &flexural strength of concrete.

  9. 76 FR 28318 - National Emission Standards for Hazardous Air Pollutants From the Portland Cement Manufacturing...

    Science.gov (United States)

    2011-05-17

    ... the status of those fuels. 74 FR at 21138. Although there is a statutory definition of solid waste in... as solid wastes or not) does not appreciably affect cement kilns' HAP emissions. 74 FR at 21138... rules regulating ] Commercial and Industrial Solid Waste Incinerators (CISWI) and proposing a...

  10. Biomonitoring of airborne particulate matter emitted from a cement plant and comparison with dispersion modelling results

    Science.gov (United States)

    Abril, Gabriela A.; Wannaz, Eduardo D.; Mateos, Ana C.; Pignata, María L.

    2014-01-01

    The influence of a cement plant that incinerates industrial waste on the air quality of a region in the province of Córdoba, Argentina, was assessed by means of biomonitoring studies (effects of immission) and atmospheric dispersion (effects of emission) of PM10 with the application of the ISC3 model (Industrial Source Complex) developed by the USEPA (Environmental Protection Agency). For the biomonitoring studies, samples from the epiphyte plant Tillandsia capillaris Ruíz & Pav. f. capillaris were transplanted to the vicinities of the cement plant in order to determine the physiological damage and heavy metal accumulation (Ca, Mn, Fe, Co, Ni, Cu, Zn, Cd and Pb). For the application of the ISC3 model, point and area sources from the cement plant were considered to obtain average PM10 concentration results from the biomonitoring exposure period. This model permitted it to be determined that the emissions from the cement plant (point and area sources) were confined to the vicinities, without significant dispersion in the study area. This was also observed in the biomonitoring study, which identified Ca, Cd and Pb, pH and electric conductivity (EC) as biomarkers of this cement plant. Vehicular traffic emissions and soil re-suspension could be observed in the biomonitors, giving a more complete scenario. In this study, biomonitoring studies along with the application of atmospheric dispersion models, allowed the atmospheric pollution to be assessed in more detail.

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

    OpenAIRE

    Kempl, J.; Copuroglu,O.

    2015-01-01

    Blast Furnace Slag (BFS) is a waste product of industrial steel production and a common additive in the cement industry in Northern European countries. However, cementitious materials made from slag-rich cement, particularly CEM III /B, are very susceptible to carbonation. Recent investigations have shown that the surface application of aqueous sodium monofluorophosphate (Na-MFP) as pre- and post-carbonation treatment can improve the surface durability of cementitious materials with a high BF...

  12. Microscopic evaluation regarding time behavior of orthodontic cements used for disjunctor cementing

    Directory of Open Access Journals (Sweden)

    Ruxandra Bartok

    2015-11-01

    Full Text Available In order to fulfill their function, orthodontic devices must be cemented on teeth using orthodontic rings. The retention of the orthodontic ring is influenced mainly by the type of dental-ring adhesion. This study was initiated to determine possible microleakage events while using zinc phosphate cement Adhesor (Spofa Dental, conventional glass ionomer Ketac Cem (3M ESPE and Fuji Ortho (GC and a compomer Transbond Plus (3M Unitek. The results of the study are consistent with those reported in the literature reference, the compomer is the preferred adhesive material for cementing the orthodontic rings, compared to conventional glass ionomer cements and zinc-phosphate cement.

  13. Resistência mecânica de compósitos cimentícios leves utilizando resíduos industriais e fibras de sisal Mechanical resistence of lightweight cement composites utilizing industrial residues and fibers of sisal

    Directory of Open Access Journals (Sweden)

    Nivaldo T. de Arruda Filho

    2012-08-01

    Full Text Available A valorização de materiais alternativos incorporados com resíduos como opção ao convencional deve possibilitar a geração de um produto com qualidade, estética, produtividade e com potencial de reduzir impactos da poluição ambiental. Este trabalho foi realizado com o objetivo de desenvolver elementos construtivos para forro e divisórias, a partir de matrizes cimentícias com incorporação de resíduos industriais (resíduo cerâmico, etil vinil acetato - EVA e fibras de sisal. Desenvolveram-se técnicas de moldagem em matrizes cimentícias autoadensáveis e se avaliou a resistência mecânica dos novos compósitos. Uma placa com resíduos de EVA foi produzida e, através de trabalhos de reologia, encontrou-se a pasta matriz de revestimento desta placa, com teor adequado de adições pozolânicas e aditivo superplastificante. Avaliaram-se as resistências mecânicas das placas, da pasta matriz de revestimento encontrada, com e sem adição de fibras, e do novo compósito formado pela união desses dois elementos. Utilizou-se a técnica de alinhamento de fibras com o intuito de incrementar resistência ao novo compósito leve. A adição da matriz com fibras alinhadas melhorou a resistência a flexão do novo compósito.The appreciation of alternative materials incorporated in waste as an option to conventional material should enable to generate a product with quality, aesthetics, productivity and reduce the potential impacts of environmental pollution. This study aims to develop constructive elements for ceilings and walls from cementitious matrix incorporating industrial waste (ceramic waste, ethyl vinyl acetate - EVA and sisal fibers. Moulding techniques to produce self-compacting cementitious matrices were developed and the strength of the new composites were evaluated. A plate with EVA waste was produced and through rheology studies, a matrix plaster for coating of plate surface was found, with appropriate content of pozzolanic and

  14. 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....

  15. Cements in radioactive waste management. Characterization requirements of cement products for acceptance and quality assurance purposes

    International Nuclear Information System (INIS)

    Cementitious materials are used as immobilizing matrices for low (LLW) and medium-level wastes (MLW) and are also components of the construction materials in the secondary barriers and the repositories. This report has concerned itself with a critical assessment of the quality assurance aspects of the immobilization and disposal of MLW and LLW cemented wastes. This report has collated the existing knowledge of the use and potential of cementitious materials in radioactive waste immobilization and highlighted the physico-chemical parameters. Subject areas include an assessment of immobilization objectives and cement as a durable material, waste stream and matrix characterization, quality assurance concepts, nature of cement-based systems, chemistry and modelling of cement hydration, role and effect of blending agents, radwaste-cement interaction, assessment of durability, degradative and radiolytic processes in cements and the behaviour of cement-based matrices and their near-field interactions with the environment and the repository conditions

  16. Reversing the trend toward failure/Revirtiendo la tendencia al fracaso

    Directory of Open Access Journals (Sweden)

    Edward J. Schauer (Estados Unidos de América

    2014-08-01

    Full Text Available In order to solve a problem or reverse a trend, the researcher must first identify the problem, and then suggest solutions or resolutions for that problem so as to offer hope for the future. From all indications, African American students are lagging behind in college education. Of those who do come to college, a troubling percentage do not persevere to graduation. Among those most at risk for failure to succeed in college are African American males. On the average, Black males in America appear to be in deep trouble: For example, many more college aged Black men are in prison than are enrolled in higher education. A Justice Policy study in 2000 (Associated Press, March 28, 2006 reported that fewer African American men were in higher education (603,000 than were in prison and jail (791,600; and the rate continues to diverge (Schauer & Schauer, 2006 & 2007a. This debilitating trend must be reversed and one available alternative is to support those who choose education. Therefore, it would seem to make sense that once these young people are in college, every effort should be made to keep them there. By studying some of the correlates of Black male success, it is hoped that more African American men can be aided toward attaining college degrees and greater career mobility through interventions more accurately focused upon meeting their precise needs (Schauer & Schauer, 2007a. Con el fin de resolver un problema o revertir una tendencia, el investigador debe primero identificar el problema y luego sugerir soluciones o resoluciones para ese problema con el fin de ofrecer esperanzas para el futuro. De todas las indicaciones, los estudiantes afroamericanos están quedando rezagados en la educación universitaria. De los que llegan a la Universidad, un porcentaje preocupante no perseverar a la graduación. Entre quienes más en riesgo por la falta de éxito en la Universidad están los hombres afroamericanos. En promedio, los varones negros en Estados

  17. Algunas Tendencias Actuales en Educación Médica

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Brailovsky

    2012-11-01

    Full Text Available Desde la revolución “flexneriana” de hace 100 años hubo muchos intentos de cambios en la enseñanza de la medicina y surgieron nuevas tendencias generales en educación médica. Principalmente surge la necesidad de superar el modelo biomédico clásico  hacia uno más centrado en la persona (y en la sociedad. El curriculum tiende a ser más competo e integral, con la incorporación de aspectos comunitarios, de integración de dimensiones clínicas y de habilidades interpersonales. La planificación curricular se adapta mejor a las necesidades del estudiante y de la sociedad. La admisión de los estudiantes y su selección, busca hacerse más inclusiva, equitativa, y basada en la ciencia de la evaluación. Aparecen modelos de universidades virtuales que seguramente en el futuro serán exitosas, a partir del rápido desarrollo de simuladores, de nuevas tecnologías de la información y del uso de redes sociales. Hay muchos ejemplos de modelos mixtos de aprendizaje a distancia y actividades presenciales (blendede-learning. Se incorpora la concepción de entrenamiento y formación multiprofesional e interprofesional, e incluso la integración de la formación de pregrado y de posgrado en algunas escuelas de acuerdo a la orientación elegida. La evaluación de los saberes y las competencias profesionales tienden a hacerse cada vez más descriptivas, con énfasis en la reflexión y en las habilidades metacognitivas, y utilizan tests sofisticados (OSCE, miniCEX, Script Concordance Tests. La formación docente tiende a ser más longitudinal, reflexiva, interactiva y favoreciendo  el compromiso personal y profesional como elemento de aprendizaje. En definitiva muchos aspectos de la educación médica está cambiando y las nuevas tendencias se van imponiendo como un medio de adaptarse a las nuevas realidades sociales. ABSTRACTSome actual trends in Medical Education. Since the “Flexneriane” revolution 100 years ago, many attempts have been

  18. 21 CFR 872.3275 - Dental cement.

    Science.gov (United States)

    2010-04-01

    ... DENTAL DEVICES Prosthetic Devices § 872.3275 Dental cement. (a) Zinc oxide-eugenol—(1) Identification. Zinc oxide-eugenol is a device composed of zinc oxide-eugenol intended to serve as a temporary tooth... chapter subject to § 872.9. (b) Dental cement other than zinc oxide-eugenol—(1) Identification....

  19. Pre-portland cements and geopolymers

    Czech Academy of Sciences Publication Activity Database

    Hanzlíček, Tomáš; Perná, Ivana; Ertl, Z.; Miller, S.M.

    2012-01-01

    Roč. 9, č. 1 (2012), s. 57-62. ISSN 1214-9705 Institutional research plan: CEZ:AV0Z30460519 Keywords : caementum * cement itious * calcareous cement Subject RIV: JN - Civil Engineering Impact factor: 0.530, year: 2011 http://www.irsm.cas.cz/materialy/acta_content/2012_01/5_Hanzlicek.pdf

  20. Chloride ingress in cement paste and mortar

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede; Hansen, Per Freiesleben; Coats, Alison M.; Glasser, Fred P.

    1999-01-01

    In this paper chloride ingress in cement paste and mortar is followed by electron probe microanalysis. The influence of several paste and exposure parameters on chloride ingress are examined (e.g., water-cement ratio, silica fume addition, exposure time, and temperature), The measurements are...

  1. 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...

  2. Investigation of a Hardened Cement Paste Grout

    DEFF Research Database (Denmark)

    Esteves, Luis Pedro; Sørensen, Eigil Verner

    This report documents a series of tests performed on a hardened cement paste grout delivered by the client, Det Norske Veritas A/S.......This report documents a series of tests performed on a hardened cement paste grout delivered by the client, Det Norske Veritas A/S....

  3. A note on cement in asteroids

    CERN Document Server

    Bilalbegovic, G

    2016-01-01

    Cement mineral tobermorite was formed in hydrothermal experiments on alternation of calcium-aluminum-rich inclusions (CAIs) in carbonaceous chondrite meteorites. Unidentified bands at 14 microns were measured for CAIs and the matrix of the Allende meteorite sample, as well as for Hektor and Agamemnon asteroids. The presence of cement nanoparticles may explain the feature at 14 microns.

  4. Staphylococcus aureus en quemaduras: estudio de incidencia, tendencia y pronóstico

    Directory of Open Access Journals (Sweden)

    A. García-Urquijo

    2015-06-01

    Full Text Available Realizamos un estudio descriptivo, longitudinal, retrospectivo de los últimos 10 años, en la Unidad de quemados del Hospital Universitario "Arnaldo Milián Castro" de Santa Clara, en Villa Clara, Cuba, con el objetivo de caracterizar el comportamiento del aislamiento de Staphylococcus aureus en heridas por quemaduras de pacientes ingresados. Se realizó con 1065 muestras tomadas por método cualitativo de hisopado, entre enero del 2002 y diciembre del 2011. Las variables utilizadas fueron: mes y año de realización, resultado del aislamiento, grupo de microorganismos y especies aisladas, series temporales y tasa pronóstico. Staphylococcus aureus resultó ser el microorganismos Gram positivo mas frecuentemente aislado (68,3%, representando entre el 7 y el 31,8% de las muestras realizadas cada año, con tasas de incidencias oscilando entre el 6,3 y 37,2 por cada 100 pacientes ingresados. Las tasas de incidencia mensuales se mantuvieron predominantemente en zonas de alerta y de seguridad durante los años 2011 y también en el seguimiento en 2012, sin que se produjeran picos epidémicos, mostrando una ligera tendencia al decremento con respecto al comportamiento de los 3 últimos años. Comprobamos después que la tasa de aislamiento para el siguiente año, 2012 fue de 9,5 por cada 100 ingresos, dentro de los límites del intervalo pronosticado según los estudios recogidos hasta 2011 (0 y 46,7 por cada 100 ingresos.

  5. Tendencias de infecciones intrahospitalarias en un centro oncológico, 1986-1996

    Directory of Open Access Journals (Sweden)

    Volkow Patricia

    2000-01-01

    Full Text Available OBJETIVO: Describir los resultados de diez años de vigilancia de infecciones intrahospitalarias (II en un centro oncológico. MATERIAL Y MÉTODOS: Es un estudio descriptivo, retrospectivo, del programa de vigilancia del Comité de Vigilancia y Control de Infecciones Intrahospitalarias del Instituto Nacional de Cancerología, realizado en 1997. Se utilizaron los criterios de infección intrahospitalaria por sitio propuestos por el Centro para la Prevención y el Control de Enfermedades de Atlanta, Georgia, de Estados Unidos de América, en 1972. De junio de 1986 a diciembre de 1996, se estudiaron 62 733 egresos. La vigilancia se realizó mediante la revisión de los expedientes de pacientes con fiebre, de aquellos que reciben antibióticos y de posoperados en los pisos de hospitalización y revisión de cultivos. Se calcularon las tasas de II por episodios/100 egresos. RESULTADOS: La tasa de infecciones intrahospitalarias por 100 egresos fue de 4.4 en 1986; 7.7, en 1987; 8.1, en 1988; 5.9, en 1989; 4.6, en 1990; 5.1, en 1991; 4.3, en 1992; 5.4, en 1993; 7.6, en 1994; 7.1, en 1995, y 8.5, en 1996. El germen más frecuentemente aislado en las II fue Escherichia coli. Los aislamientos de hongos y los de enterococo se incrementaron en casi siete veces desde 1987. CONCLUSIONES: Se observó un incremento en la tasa de infecciones hospitalarias en los últimos cuatro años. Al menos dos factores contribuyeron a esta tendencia: la aplicación de un sistema de vigilancia más experimentado, el cual hizo que disminuyera el subregistro, y el aumento real en la frecuencia de tales infecciones.

  6. El "boom" de la ciencia política en Chile: escuelas, mercado y tendencias

    Directory of Open Access Journals (Sweden)

    Claudio Fuentes

    2005-01-01

    Full Text Available Resumen La ciencia política en Chile ha estado tradicionalmente marcada por su eclecticismo teórico y la limitada cantidad de escuelas de formación. Sin embargo, a comienzos de esta década, se dio un giro relevante en la disciplina a partir de la apertura de un gran número de departamentos que imparten dicha carrera, particularmente a nivel de pregrado. En este artículo se da cuenta de este reciente desarrollo a partir del estudio analítico descriptivo de las mallas curriculares y de los perfiles de los profesionales que enseñan en dichas carreras. Se concluye que, aunque existe una importante transición disciplinaria con tendencias a la profesionalización, todavía se advierten un sinnúmero de precariedades en el ejercicio de la disciplina. Se advierte que gran parte del cambio se debe a las fuerzas del mercado y que es relevante una reflexión sobre qué tipo de profesionales se están formando y para qué.Abstract The development of political science in Chile has traditionally been defined by its eclecticism and the relatively small number of schools on this field. However, at the beginning of this decade, an important twist was taken after the opening of a great number of schools of political science in several universities within the country. This article describes this new development, studying the curricula and professional profiles of the professors who are teaching in such schools. The authors address that, even though it is possible to observe a relevant transition in the discipline in this country particularly concerning the professionalization of the field, there still several weaknesses to be solved. It is argued that market forces have driven such process and that it is crucial to think about the type of professionals are being instructed.

  7. ENFOQUE POR COMPETENCIAS Y MERCADO DE TRABAJO. NUEVAS TENDENCIAS PARA LA EDUCACIÓN UNIVERSITARIA

    Directory of Open Access Journals (Sweden)

    Luis Muñoz Varela

    2012-01-01

    Full Text Available En este ensayo se realiza un análisis acerca de las principales y nuevas tendencias que hoy caracterizan la organización del mercado de trabajo y la demanda de nuevos perfiles profesionales, en el marco de la globalización económica y de la sociedad de la información y el conocimiento. Se analiza, a tal efecto, la propuesta pedagógica del enfoque por competencias que, desde hace al menos dos décadas, ha sido impulsada y promovida por parte de autoridades de gobierno, las instituciones del mercado de trabajo, algunas instituciones de educación superior y, también, de manera especial por organismos multilaterales tales como el Banco Mundial y la Unión Europea. Con base en los estudios publicados por dos reconocidos especialistas en el campo del currículum, el análisis procura identificar la naturaleza del enfoque por competencias, su heurística y teleología pedagógica, así como las repercusiones que acarrea para el proyecto de formación profesional en una institución de educación superior. El ensayo se ocupa, asimismo, en indicar la relación que existe entre el enfoque por competencias y los cambios de perspectiva que la globalización económica y la sociedad de la información y el conocimiento involucran, a propósito de la concepción del conocimiento y de la relación e implicaciones que esta tiene para la educación, en materia de organización curricular y de perspectivas pedagógicas.

  8. Métodos de control en sistemas domóticos: últimas tendencias en sistemas distribuidos

    Directory of Open Access Journals (Sweden)

    Moreno Navarro, I.

    1999-02-01

    Full Text Available Control systems lie amongst the most difficult issues to be tackled when it comes to designing home automation systems. Two classical tendencies may be considered to solve this problem. The first one consists of a centralised control system, whereas the second option advocates for a distributed network, where piece would take up certain responsibilities in the control of the whole system. In this paper we analyse some of the latest developments as regards programming distributed networks, focusing on home automation, specially Java and the latest Jini environments have dramatically improved the potential of such kind of distributed systems, thanks to them, it is possible to build a heterogeneous network including devices from different brands which work in collaborative systems, thus avoiding complex configurations.

    Uno de los aspectos más delicados a la hora de diseñar un sistema domótico es el que se refiere al modelo de control que deseamos establecer. Podemos considerar dos tendencias clásicas: la que trata de establecer un control centralizado del sistema y la que propone un control mucho más descentralizado, donde cada aparato seria responsable de cierta parte de la gestión del control ejercido sobre toda la red. En este articulo tratamos de profundizar en las últimas novedades aparecidas en el campo de la programación de los controladores asociados a una red domótica, en particular Java y el más reciente Jini, que aportan una serie de soluciones que facilitan la compatibilidad entre dispositivos de distintos fabricantes y apuestan claramente por una arquitectura de tipo distribuido, dotando a las redes domóticas de una flexibilidad y un potencial de crecimiento inusitados.

  9. Implications of WTO Accession for Selected Domestic Industries of Laos

    OpenAIRE

    Lord, Montague J.

    2010-01-01

    The study examines the implications of Lao PDR’s WTO accessions on the domestic cement, steel bar and brewery industries with a view to developing recommendations on how to concurrently manage the Government’s domestic strategic objectives with the country’s effective involvement in the global economy. Calculations of total protection (TE) to the industries shows that beer receives the highest level of protection (110%), followed by steel bars (17%) and cement (16%). The actual level of effec...

  10. Immobilization of Radioactive Waste in Different Fly Ash Zeolite Cement Blends

    International Nuclear Information System (INIS)

    The problem of radioactive waste management has been raised from the beginning use of nuclear energy for different purposes. The rad waste streams produced were sufficient to cause dangerous effects to man and its environment. The ordinary portland cement is the material more extensively used in the technologies of solidification and immobilization of the toxic wastes, low and medium level radioactive wastes. The production of portland cement is one of the most energy-intensive and polluting. The use of high energy in the production causes high emission due to the nature and processes of raw materials. The cement industry is responsible for 7% of the total CO2 emission. Thus, the cement industry has a crucial role in the global warming. The formation of alite (Ca3SiO5), which is the main component of the Portland cement clinker, produces a greater amount of CO2 emission than the formation of belite (Ca2SiO4). The proportion of alite to belite is about 3 in ordinary Portland clinker. Therefore, by decreasing this proportion less CO2 would be emitted. Furthermore, if industrial byproducts such as fly ash from thermal power station or from incineration of municipal solid wastes have the potential to reduce CO2 used as raw materials and alternative hydrothermal calcination routes are employed for belite clinker production, CO2 emission can be strongly reduced or even totally avoided. The availability of fly ash will help in reducing the CO2 emissions and will also help in resolving, to a great extent, the fly ash disposal problem. This thesis is based on focusing on the possibility of using fly ash as raw materials to prepare low cost innovation matrices for immobilization of radioactive wastes by synthesizing new kind of cement of low consuming energy. The synthesis process is based on the hydrothermal-calcination route of the fly ash without extra additions.

  11. Application of Neutron imaging in pore structure of hydrated wellbore cement: comparison of hydration of H20 with D2O based Portland cements

    Science.gov (United States)

    Dussenova, D.; Bilheux, H.; Radonjic, M.

    2012-12-01

    Wellbore Cement studies have been ongoing for decades. The studies vary from efforts to reduce permeability and resistance to corrosive environment to issues with gas migration also known as Sustained Casing Pressure (SCP). These practical issues often lead to health and safety problems as well as huge economic loss in oil and gas industry. Several techniques have been employed to reduce the impact of gas leakage. In this study we purely focus on expandable liners, which are introduced as part of oil well reconstruction and work-overs and as well abandonment procedures that help in prevention of SCP. Expandable liner is a tube that after application of a certain tool can increase its diameter. The increase in diameter creates extra force on hydrated cement that results in reducing width of interface fractures and cement-tube de-bonding. Moreover, this also causes cement to change its microstructure and other porous medium properties, primarily hydraulic conductivity. In order to examine changes before and after operations, cement pore structure must be well characterized and correlated to cement slurry design as well as chemical and physical environmental conditions. As modern oil well pipes and tubes contain iron, it is difficult to perform X-ray tomography of a bulk measurement of the cement in its wellbore conditions, which are tube wall-cement-tube wall. Neutron imaging is a complementary technique to x-ray imaging and is well suited for detection of light elements imbedded in metallic containers. Thus, Neutron Imaging (NI) is investigated as a tool for the detection of pore structure of hydrated wellbore cement. Recent measurements were conducted at the Oak Ridge National Laboratory (ORNL) High Flux Isotope Reactor (HFIR) neutron imaging facility. NI is is highly sensitive to light elements such as Hydrogen (H). Oil well cements that have undergone a full hydration contain on average 30%-40% of free water in its pore structure. The unreacted water is the main

  12. Sulfate attack of Algerian cement-based material with crushed limestone filler cured at different temperatures

    OpenAIRE

    SENHADJI, Yassine; Mouli, Mohamed; KHELAFI, Hamid

    2010-01-01

    The cement production industry is one of the main consumers of energy and raw materials. Over the last years, a great effort has been made in order to substitute clinker for less energy demanding materials. In many countries, it is popular to use limestone as admixture material to improve the consistency of concrete. Nevertheless, the construction industry needs durable materials with improved properties. Following this objective, this work is a part of an ongoing project developed ...

  13. Tendencias de mortalidad por cánceres atribuibles al tabaco en México

    Directory of Open Access Journals (Sweden)

    Víctor José Tovar-Guzmán

    2002-01-01

    Full Text Available Objetivo. Describir la tendencia de la mortalidad por cáncer atribuible al consumo de tabaco, particularmente neoplasias del pulmón, en México, durante el periodo 1980-1997. Material y métodos. Se hizo un análisis de tendencias de mortalidad para cada tipo de cáncer asociado con el tabaco, según la Clasificación Internacional de Enfermedades. Las tasas cruda y ajustada de mortalidad fueron estimadas en términos de edad, género, causa básica de la muerte y año, entre 1980 y 1997. Se estimó la razón de género y proporción relativa para los casos que estaban en el grupo de edad entre 35 y 64 años y para toda la población estudiada. Como denominador se utilizaron las proyecciones por edad calculadas por el Consejo Nacional de Población (1970-2010. Resultados. La razón de género para las tasas de mortalidad por cáncer de laringe, esófago, cavidad oral y faringe fue de 2.10:1.00 (hombre: mujer. La razón de género para el cáncer de laringe es enorme: 4.21: 1.00, probablemente debida a la mayor prevalencia de hombres fumadores de tabaco. La proporción relativa estimada, usando la mortalidad total debida a tumores malignos, entre 1980 y 1997 fue la siguiente: cáncer de pulmón 12.31%, laringe 1.71%, esófago 1.55% y cavidad oral/faringe 1.49%. El antecedente de tabaquismo tiene correlación con la tendencia de la tasa de mortalidad por cáncer del pulmón (Beta: 0.910, IC 95%: 1.097-1.797; R² 0.827. Para los grupos sociales mas pobres, por entidad federativa, la correlación está invertida (Beta: -0.510, IC 95%: -0.170, -0.039, R²: 0.260. Conclusiones. En México, la mejoría en el diagnóstico, la transición demográfica y el incremento del consumo de tabaco son, probablemente, los principales factores a los que se atribuye la tasa de mortalidad por cáncer. No obstante, otras variables asociadas con el estilo de vida, como urbanización, actividad física, ingesta de carotenoides y otros componentes dietéticos y t

  14. Conditioning of radioactive waste solutions by cementation

    International Nuclear Information System (INIS)

    For the cementation of the low and intermediate level evaporator concentrates resulting from the reprocessing of spent fuel numerous experiments were performed to optimize the waste form composition and to characterize the final waste form. Concerning the cementation process, properties of the waste/cement suspension were investigated. These investigations include the dependence of viscosity, bleeding, setting time and hydration heat from the waste cement slurry composition. For the characterization of the waste forms, the mechanical, thermal and chemical stability were determined. For special cases detailed investigations were performed to determine the activity release from waste packages under defined mechanical and thermal stresses. The investigations of the interaction of the waste forms with aqueous solutions include the determination of the Cs/Sr release, the corrosion resistance and the release of actinides. The Cs/Sr release was determined in dependence of the cement type, additives, setting time and sample size. (orig./DG)

  15. 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.

  16. Pack cementation coatings for alloys

    Energy Technology Data Exchange (ETDEWEB)

    He, Yi-Rong; Zheng, Minhui; Rapp, R.A. [Ohio State Univ., Columbus, OH (United States)

    1996-08-01

    The halide-activated pack cementation process was modified to produce a Ge-doped silicide diffusion coating on a Cr-Cr{sub 2}Nb alloy in a single processing step. The morphology and composition of the coating depended both on the composition of the pack and on the composition and microstructure of the substrate. Higher Ge content in the pack suppressed the formation of CrSi{sub 2} and reduced the growth kinetics of the coating. Ge was not homogeneously distributed in the coatings. In cyclic and isothermal oxidation in air at 700 and 1050{degrees}C, the Ge-doped silicide coating protected the Cr-Nb alloys from significant oxidation by the formation of a Ge-doped silica film. The codeposition and diffusion of aluminum and chromium into low alloy steel have been achieved using elemental Al and Cr powders and a two-step pack cementation process. Sequential process treatments at 925{degrees}C and 1150{degrees}C yield dense and uniform ferrite coatings, whose compositions are close to either Fe{sub 3}Al or else FeAl plus a lower Cr content, when processed under different conditions. The higher content of Al in the coatings was predicted by thermodynamic calculations of equilibrium in the gas phase. The effect of the particle size of the metal powders on the surface composition of the coating has been studied for various combinations of Al and Cr powders.

  17. ROTARY SCREW SYSTEMS IN CEMENT

    Directory of Open Access Journals (Sweden)

    Taratuta V. D.

    2016-01-01

    Full Text Available 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 geometrical shapes with form inside the screw breaks or smooth edges, screw surfaces and screw grooves. It is shown that the housing of the rotary kiln is expedient to produce helical surfaces whose centers of curvature are located within the housing. Using the proposed constructions rotary kiln during the firing when preparing cement wedge can increase the speed of rotation of the housing, furnaces 5-10 times due to changes in the rotary-screw systems increase efficiency and reduce the size of furnaces

  18. 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 (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.

  19. Uniaxial tensile test on a new cement composite having a hardening behaviour

    OpenAIRE

    BOULAY, C; Rossi, P; TAILHAN, JL

    2004-01-01

    The LCPC patented a new cement composite (CEMTEC multiscale), which have been developed to be stress hardening in tension and to have an ultra-high tensile strength. It is a multi-scale cement composite. One of the industrial applications aimed is related to thin slabs. Consequently, the research objective is to characterize the tensile behaviour of this material used is a thin bended slab. To achieve that, this tensile behaviour is measured from a bending test (easier to perform than an unia...

  20. 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

  1. 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

  2. Extraoral Cementation Technique to Minimize Cement-Associated Peri-implant Marginal Bone Loss: Can a Thin Layer of Zinc Oxide Cement Provide Sufficient Retention?

    Science.gov (United States)

    Frisch, Eberhard; Ratka-Krüger, Petra; Weigl, Paul; Woelber, Johan

    2016-01-01

    This report describes the use of laboratory-fabricated crown intaglio replicas for extraorally prepared cementation of fixed restorations to implants. This technique minimizes excess cement and may therefore reduce the risk of cement-related marginal peri-implant bone loss. It is unclear whether the remaining thin layer of luting agent provides sufficient retention if low-adhesive zinc oxide (ZnO) cement is used. In 85 consecutive patients, 113 single crowns were cemented to implants using extraoral cementation technique (ECT) and ZnO cement. All patients were followed for 6 months and investigated for decementation. Seven events of decementation (incidence: 6.19%) were found in 7 patients (8.24%). ECT may represent a viable cementation technique for implant-supported single crowns, even using low-adhesion cements. PMID:27479343

  3. Causas de muerte en la mujer y su tendencia en los últimos 23 años en la Argentina

    Directory of Open Access Journals (Sweden)

    María I. Sosa Liprandi

    2006-01-01

    Full Text Available Objetivo Analizar la tendencia de la mortalidad en la mujer y reconocer el impacto de la mortalidad cardiovascular en la Argentina en el período 1980-2003. Material y métodos Se analizó la base de datos de las Estadísticas Vitales del Ministerio de Salud y Medio Ambiente. Se utilizó el certificado de defunción basado en la Clasificación Internacional de Enfermedades (CIE 9ª y 10ª Revisión. Se calculó la tasa bruta de mortalidad anual por diagnóstico en la población general y la tasa específica corregida por edad y sexo por cien mil habitantes según el censo poblacional. Resultados La mortalidad cardiovascular presenta una reducción global de la tasa bruta de mortalidad anual del 34%. La tendencia descendente fue más manifiesta para los hombres (35% que para las mujeres (27%. En 2003, en la mujer, la mortalidad cardiovascular (33% superó a la mortalidad por cáncer (18%. El mayor impacto se observa a partir de los 75 años, con una duplicación de la tasa de mortalidad por insuficiencia cardíaca y accidente cerebrovascular con respecto al género masculino. Conclusiones La mortalidad cardiovascular es la primera causa de muerte en las mujeres. La frecuencia relativa de mortalidad cardiovascular en la mujer supera a la del hombre desde 1980 hasta la actualidad. Sin embargo, la tendencia descendente fue más significativa en los hombres en los últimos 23 años. A partir de los 65 años, las mujeres representan el grupo con mayor impacto en la mortalidad cardiovascular. Estas observaciones refuerzan la necesidad de implementar precozmente estrategias preventivas y de educación en la comunidad.

  4. Modelling Quartz Cementation of Quartzose Sandstones

    Energy Technology Data Exchange (ETDEWEB)

    Wangen, Magnus

    1999-10-01

    Porosity estimation in sandstones is an important part of oil reservoir quality estimations, as porosity is lost during burial because of mechanical compaction and quartz cementation. In this report, cementation of quartzose sandstones is modelled assuming that the main source of silica is quartz dissolved at stylolites. The cementation process is shown to operate in one of two different regimes depending on the Damkohler number for diffusion. The regime, where diffusion of silica from the stylolites is a faster process than precipitation, is characterized by a nearly constant supersaturation between the stylolites. This regime, which spans the depth interval of quartz cementation for close stylolites, allows approximate analytical expressions for the porosity evolution as a function of time and temperature. An expression is derived for the temperature where half the initial porosity is lost during constant burial along constant thermal gradient. This expression is used to study the sensitivity of all parameters which enter the cementation process. The cementation process is shown to be particularly sensitive to the activation energy for quartz dissolution. The expression for the porosity decrease under constant burial is generalized to any piecewise linear burial and temperature history. The influence of the burial histories on the cementation process is studied. 32 refs., 16 figs., 1 tab.

  5. Energy auditing and recovery for dry type cement rotary kiln systems - a case study

    Energy Technology Data Exchange (ETDEWEB)

    Engin, T.; Ari, V. [University of Sakarya (Turkey). Dept. of Mechanical Engineering

    2005-03-01

    Cement production has been one of the most energy intensive industries in the world. In order to produce clinker, rotary kilns are widely used in cement plants. This paper deals with the energy audit analysis of a dry type rotary kiln system working in a cement plant in Turkey. The kiln has a capacity of 600 ton-clinker per day. It was found that about 40% of the total input energy was being lost through hot flue gas (19.15%), cooler stack (5.61%) and kiln shell (15.11% convection plus radiation). Some possible ways to recover the heat losses are also introduced and discussed. Findings showed that approximately 15.6% of the total input energy (4 MW) could be recovered. (author)

  6. Characterization of different types of ceramic waste and its incorporation to the cement paste

    International Nuclear Information System (INIS)

    The porcelain tike is a product resulting from the technological development of ceramic plating industry. Its large acceptation by the consumer market is probably linked with certain properties, such as low porosity, high mechanical resistance, facility in maintenance, besides being a material of modern and versatile characteristics. The aim of this work was characterizing the different ceramic wastes (enameled and porcelain tike) and evaluating its influence on the mechanical behavior in cement pastes. The wastes were characterized through the determination of its chemical composition, size particle distribution and X-ray diffraction. Cement pastes + wastes were prepared in 25% and 50% proportions and glue time determination, water absorption and resistance to compression assays were taken. The results indicate that although the wastes don't show any variation in the elementary chemical composition, changes in the cement paste behavior related to the values of resistance to compression were observed. (author)

  7. Reactive transport modeling of interaction processes between clay stone and cement

    International Nuclear Information System (INIS)

    The disposal of radioactive wastes in clayey formations may require the use of large amounts of concrete and cement. The chemical interactions between these industrial materials and the host rock are modeled with the reactive transport code HYTEC for time scales and a geometry representative of disposal projects. The pH evolution, a key parameter in element mobility, is studied more specifically. It depends on several interdependent processes: i) diffusion of highly alkaline cement pore solution, ii) strong buffering related to important mineral transformations both in the cement and in the clay, and iii) cation exchange processes, beyond the zone of intense mineral transformations. In addition, precipitation of secondary minerals may lead to a partial or complete clogging of the pore space, almost stopping the propagation of the high pH plume. In a second step, preliminary results on the migration of strontium and uranium in these strongly coupled systems are presented as an example of transport parameter derivation. (authors)

  8. Energetic and exergetic assessment of a trass mill process in a cement plant

    International Nuclear Information System (INIS)

    Cement production has become one of the most intensive energy industries in the world. For producing it, addition materials have been widely used in cement factories. The main objective of this study is to assess the performance of a trass mill in a cement plant based on the actual operational data using energy and exergy analysis method. In this regard, the values for energy consumption and losses throughout the production process are described. In the process, the overall exergy efficiencies are found to be slightly less than the corresponding energy efficiencies; e.g. 74% and 10.68% for energy and exergy efficiency, respectively. Using energy recovery systems, waste heat energy may be captured, while energy and exergy efficiency values can be improved to 84% and 48%, respectively. It may also be concluded that the analyses reported here will provide the investigators with knowledge about how effectively and efficiently a sector uses its energy resources.

  9. On the Fresh/Hardened Properties of Cement Composites Incorporating Rubber Particles from Recycled Tires

    Directory of Open Access Journals (Sweden)

    Alessandra Fiore

    2014-01-01

    Full Text Available This study investigates the ameliorative effects on some properties of cement-based materials which can be obtained by incorporating rubber particles as part of the fine aggregates. The aim is to find out optimal cement composite/mortar mixtures, containing recycled-tyre rubber particles, suitable for specific engineering applications. Different percentages of rubber particles, from 0% to 75%, were used and, for each percentage, the suitable amount of sand was investigated in order to achieve the best fresh/hardened performances. In particular the following characteristics were examined: density, compressive strength, modulus of elasticity, shrinkage, weight loss, flexural behaviour, thermal conductivity, rapid freezing and thawing durability, and chloride permeability. The experimental results were compared with the ones of cement composite specimens without rubber aggregates. Test results show that the proposed rubberized mortar mixes are particularly suitable for some industrial and architectural applications, such as under-rail bearings, road constructions, paving slabs, false facades, and stone backing.

  10. The Specification of Cement Powders for Waste Encapsulation Processes at Sellafield site

    International Nuclear Information System (INIS)

    Requirements are described for Portland Cement (CEM I), Ground Granulated Blast-furnace Slag (GGBS) and Fly Ash (FA) powders used for the encapsulation of Intermediate Level Radioactive Waste (ILW) in UK, with particular reference to Sellafield site encapsulation processes. Differences between the powders used by the UK nuclear industry and the equivalent British and European cement standards are explained. Research over the last 20 years to respond to changes in the performance of these powders is summarised and options for dealing with potential future changes are discussed. These include the use of special blends of GGBS to achieve the desired flow properties or alternatively poly-carboxylate super-plasticizers to produce grouts with consistent performance using cement powders with a wide range of composition. (authors)

  11. Development of construction specifications and quality assurance criteria for compacted fly ash-cement feedlot pads

    Energy Technology Data Exchange (ETDEWEB)

    Kalinski, M.E.; Bicudo, J.R.; Hippley, B.; Nanduri, S.R. [University of Kentucky, Lexington, KY (United States). Dept. of Civil Engineering

    2005-05-01

    Numerous industrial uses have been identified for fly ash that economically benefits both the fly ash producer and the fly ash user. One such use is the construction of compacted fly ash-cement pads for hay storage and for livestock heavy traffic areas, including traffic lanes, feeding areas, watering sites, loafing lots, and feedlots. The use of a variety of pads (e.g. soil-cement, fly ash, geotextile-gravel) in feedlots has been shown to improve daily gain and reduce hoof disease in cattle. However quality assurance methods for construction of such pads are lacking. Therefore, a laboratory study was performed to develop a quantitative approach to construction quality assurance (CQA) testing of compacted fly ash-cement pads.

  12. Tendencias en la distribución de probabilidades de lluvias y caudales en algunas cuencas Colombianas

    OpenAIRE

    Rave Herrera, Claudia Cristina; Mantilla Gutiérrez, Ricardo; Poveda Jaramillo, Germán

    2001-01-01

    Se examina la evolución temporal de los cuantíles de la función de distribución de probabilidad de registros de precipitación y caudal a nivel diario en Colombia, dentro de una búsqueda de señales de cambio climático. Se usan pruebas estadísticas de cambio en la media, en la varianza y de tendencias de las series de cuantíles. Las series de registros de lluvia y caudal corresponden a 10 departamentos de Colombia y se dividen en dos grupos según el periodo de registro. DISTRIBUCIONES...

  13. Tendencias del periodismo narrativo actual : Las nuevas formas de contar historias en revistas y cronistas latinoamericanos de hoy

    OpenAIRE

    Bonano, Mariana

    2014-01-01

    Las prácticas del periodismo narrativo, hoy ineludiblemente asociadas a la producción de revistas y medios digitales, integran un corpus heterogéneo de textos y de autores de procedencia diversa. El presente trabajo se propone esbozar un breve panorama de las tendencias que confluyen en la actualidad en este quehacer profesional, al tiempo que focaliza la crónica contemporánea como la forma discursiva que en sus diferentes registros, asume un modo de escritura alternativo al de la noticia y a...

  14. Condiciones, procesos y tendencias de la administración pública contemporánea

    OpenAIRE

    Ricardo Uvalle Berrones

    2009-01-01

    Analizar las tendencias contemporáneas de la administración pública con base en los procesos de cambio generados en la sociedad y el Estado, los cuales son influidos por factores que impulsan a la globalidad, las reformas institucionales, el rediseño de los sistemas de gestión, la importancia de fortalecer las capacidades directivas y el imperativo de valorar a la democratización como un medio que permite a las instituciones administrativas abordar nuevos y viejos problemas más allá de plante...

  15. Tendencias de largo plazo en cinco índices de estabilidad atmosférica en Colombia

    OpenAIRE

    Cantor Gómez, Diana; Ochoa Jaramillo, Andrés

    2011-01-01

    Se realizan pruebas estadísticas para evaluar la existencia de tendencias de largo plazo en series mensuales de valores máximos, medios y mínimos de cinco índices de estabilidad atmosférica calculados a partir de registros de radiosondeos. Los índices estudiados fueron el Lifted Index LI), el índice K, el índice de Total de Totales (TT), el índice de Energía Potencial Disponible Convectiva (CAPE) y el índice de Showalter (SWI).

  16. Tendencias en las tasas de incidencia de cáncer colorrectal en Navarra en el periodo 1990-2005

    OpenAIRE

    Etxeberria Andueza, Jaione; Ugarte Martínez, María Dolores; Barricarte Gurrea, Aurelio; Goicoa Mangado, Tomás; Moreno Iribas, C.; Azagra, M. J.; San Roman, E; Burgui, R.; Fernández Militino, Ana; E. Ardanaz

    2012-01-01

    Fundamento. En España, se ha observado un aumento de la incidencia de cáncer colorrectal (CCR) en ambos sexos en los últimos años, posiblemente debido a las mejoras diagnósticas, a la occidentalización de la dieta y al empeoramiento de los niveles de obesidad entre otros. En este trabajo se han estudiado las tendencias de la incidencia de CCR en las diferentes áreas de salud de Navarra (norte de España) durante el período 1990-2005. Métodos. Para cada sexo y área, se o...

  17. Tendencia de la tasa de mortalidad en una prisión española (1994-2004

    Directory of Open Access Journals (Sweden)

    Enrique Jesús Vera Remartínez

    2005-01-01

    Full Text Available Fundamento: Hay pocos trabajos sobre mortalidad en el ámbito penitenciario. El objetivo es describir las causas, tasas de mortalidad y su tendencia en una prisión española. Métodos: Estudio descriptivo, de los fallecimientos en una prisión entre 01-01-1994 y 31-12-2004. Se recogieron las variables edad, sexo, fecha del óbito, serología VIH, número de CD4+ en su caso, y causa de muerte según la clasificación: muerte por VIH, por enfermedad no VIH, suicidio, intoxicación por drogas, y accidentes. Previa estandarización indirecta de tasas, comparamos la mortalidad del Centro con la del resto de las prisiones españolas. Establecimos la tendencia de las tasas de mortalidad mediante un modelo de regresión lineal. Resultados: 42 muertes, 41 hombres, 1 mujer. Mediana de edad de 33,10 años (27,72 - 36,12; IQR: 8,40. 30 (71,4% VIH+, con mediana de 177 linfocitos CD4+/µl 20 pacientes (45,24% fallecieron por VIH, 15 (38,10% por enfermedades no VIH, 3 (7,14% suicidios, 3 (7,14% intoxicaciones por drogas y 1 (2,38% accidentalmente. Las tasas crudas de mortalidad estuvieron entre 12,605‰ internos/año en 1997 y 1,758‰ internos/año en 2003, con tendencia descendente a razón de 0,976 muertes‰ internos/año (IC95%: 0,399-1,552; p=0,004. Estandarizando tasas nos corresponderían 28,6 muertes esperadas en el período, con una SMR de 1,4679. Conclusiones: Aunque la tendencia es descendente, la tasa de mortalidad obtenida en el período estudiado fue mayor que la esperada. La principal causa de mortalidad fue el síndrome de inmunodeficiencia adquirida.

  18. Sistemas Integrados de Gestión Empresarial : Evolución histórica y tendencias de futuro

    OpenAIRE

    Oltra Badenes, Raúl Francisco

    2012-01-01

    En el presente libro se presenta una investigacion cientifica llevada a cabo por el autor en la que se estudia la posible evolucion que los sistemas de informacion para la gestion de empresas tendran en un futuro cercano, identificando para ello las principales las tendencias y lineas de desarrollo que estos sistemas van a seguir en los proximos años. Este es el punto de partida de diversas lineas de investigacion que se estan llevando a cabo en la actualidad, a traves de diferentes proyectos...

  19. 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.

  20. Thermal analysis of borogypsum and its effects on the physical properties of Portland cement

    International Nuclear Information System (INIS)

    Borogypsum, which consists mainly of gypsum crystals, B2O3 and some impurities, is formed during the production of boric acid from colemanite, which is an important borate ore. In this study, the effect of borogypsum and calcined borogypsum on the physical properties of ordinary Portland cement (OPC) has been investigated. The calcination temperature and transformations in the structures of borogypsum and natural gypsum were determined by differential thermal analysis (DTA), thermogravimetric analysis (TGA) and X-ray diffraction (XRD) techniques. Thermal experiments were carried out between ambient temperature and 500 deg. C in an air atmosphere at a heating rate of 10 deg. C min-1. After calculation of enthalpy and determination of conversion temperatures, borogypsum (5% and 7%), hemihydrate borogypsum (5%) and natural gypsum (5%) were added separately to Portland cement clinker and cements were ground in the laboratory. The final products were tested for chemical analysis, compressive strength, setting time, Le Chatelier expansion and fineness properties according to the European Standard (EN 196). The results show that increasing the borogypsum level in Portland cement from 5% to 7% caused an increase in setting time and a decrease in soundness expansion and compressive strength. The cement prepared with borogypsum (5%) was found to have similar strength properties to those obtained with natural gypsum, whereas a mixture containing 5% of hemihydrate borogypsum was found to develop 25% higher compressive strength than the OPC control mixtures at 28 days. For this reason, utilization of calcined borogypsum in cement applications is expected to give better results than untreated borogypsum. It is concluded that hemihydrate borogypsum could be used as a retarder for Portland cement as an industrial side. This would play an important role in reducing environmental pollution