Papers by Keyword: Raw Material

Abstract: Geopolymer cement is an aluminosilicate material which activated by the alkaline solution. With appropriate heat curing regimes, geopolymer cement could achieve an excellent performance as construction material. Apart from that, geopolymer cement is one of the alternative cementitious materials for green construction as its raw starting materials could be any pozzolanic industrial by-products. Global carbon-dioxide emission from Portland cement consumption could be reduced with the replacement of that geopolymer cement. Therefore, the development of geopolymer cement is receiving much more attention. However, various kinds of materials have been used as geopolymer precursors. The main aim of this paper is, thus, to summarize current information on the usage of raw materials in geopolymer production by categorize its types and sources. The summarised details of chemical composition and compressive strength could provide a guide line for readers to evaluate possible reactions or outputs of their selected local raw materials as well as the prediction of material’s combination for the improvement of targeted strength of each possible prime material.

Abstract: The study presents the extraction of collagen, a product of high value, from fleshings form hides. After testing several collagen extraction procedures we have proposed the simple and effective method to extract collagen from collagen-containing wastes of the leather industry. The unified method is based on the extraction of collagen using acetic acid in the presence of EDTA and included two repeated extraction stages. Qualitative analysis of the collagen using the disk-electrophoresis method showed a different ratio of monomers, dimers and other proteins.

Abstract: The Santa Gertrudes ́ Ceramic Polo is the Brazilian region with national and international prominence in the manufacturing of ceramic tiles. Some raw materials used by ceramic industry and coatings industries in this region were characterized in terms of chemical-mineralogical and microscopic view, in order to promote the best technological characterization of them. For this, chemical analysis of major elements and trace X-ray diffraction and microscopic analysis by SEM, TEM and Electron microprobe were performed by ICP-MS. The results showed that the raw materials commonly referred to as "clays" are actually constituted by various mineral phases, which directly influence the properties of the same ceramics. Also showed that, by virtue of this constitution, different formulations can be developed, using the best raw materials found in the region of Santa Gertrudes, SP.

Abstract: Selection of reducing agents for the ferrosilicon smelting process requires consideration of several difficult to reconcile criteria. The carbon reducers are not only a source of carbon as a substrate of the silica reduction reaction, but also play an important role by acting as a gas filter at the upper zones in working space of the ferrosilicon furnace. Reactivity of carbon reducers to SiO and degree of conversion on the SiC carbide are directly affecting the silicon recovery as well as the efficiency of the ferrosilicon process. The simultaneous fulfillment all requirements are difficult to satisfy by using only one type the reducer in the charge for the ferrosilicon process. This requires the use of a mixture reducers, and the adoption of a compromise that all requirements are met in the best possible extent. To choose the composition of carbon reducers mixture has been used simple physico-chemical model of the ferrosilicon process with two reaction zones between which there is a mass transfer. It has been shown that in the charge for the ferrosilicon furnace about 30% mass of C_fix carbon resulting from the reaction stoichiometry of silica reduction process should be in the form of the reducer with increased to SiO reactivity.

Abstract: A process improvement of incoming inspection for the materials used by a steelmaking enterprise is explained in this paper. The applied methods were described with examples considering the need of the improved process. The process complexity is explained in turn by the existence of the involved actors that need to exchange information about the inspected materials. The results obtained by the improved process justify the action started in 2012 for the incoming inspection process by a more constant quality level of the materials, reduction of the overall process duration, better materials information exchange and a convenient method for supplier surveillance and evaluation.

Abstract: High alkali aluminosilicate glass batches were prepared by five different raw materials, reaction heat of which in melting process was studied by means of DSC thermal analysis method. The results show that reaction heat of batches in the heating process of 25-1600°C exists a significant difference, and which is among 4396.38 J/g-5311.14 J/g, moreover the least is the batches using petalite, while the most is spodumene. In the whole heating process, 380-800°C is carbonate decomposition stage, which accounts for 42-46% of the total absorbed heat; and 800-1200°C is silicate reaction stage, 40-50%; and 1200-1600°C is glass clarify and homogenization phase , 6%-16%. Therefore, carbonate decomposition and silicate reaction is the main part of batches heat consumption, the optimization scheme for materials has a significant effect on energy saving and emission reduction.

Abstract: The accumulation of garbage in urban centers is, undoubtedly, one of the major environmental problems of today. The high costs of implementation and maintenance of collection systems and garbagess treatment, have often,taken to failure of government attempts to resolve this issue.

Abstract: Cube crushing strength, resistivity and gas adsorption analysis of mineral admixture concrete are tested to analysis the effect of raw material on resistivity and its regression relationship with concrete microcosmic pore structure index. Test results show that concrete resistivity at different age increases with the increase of cementitious material and cement dosage, and both has a good nonlinear regression relationship. Concrete resistivity at different age decreases with the increase of 56d HK method cumulative pore volume, 7d and 14d resistivity has a good linear correlation relationship with 56d HK method cumulative pore volume. 28d and 56d resistivity has a good nonlinear regression relationship with 56d HK method cumulative pore volume. Concrete resistivity at different age decreases with the increase of 56d BJH method cumulative adsorption pore radius, and both has a good nonlinear regression relationship.

Abstract: Cube crushing strength, resistance to chloride penetration and gas adsorption analysis of mineral admixture concrete are tested to analyze the effect of raw material on chloride diffusion coefficient and its regression relationship with concrete microcosmic pore structure index. Test results show that chloride diffusion coefficient at different age increased with the increase of water-binding material ratio, decreased with the increase of cement dosage and both appeared a good nonlinear regression relationship. Chloride diffusion coefficient at different age increased with the increase of concrete microcosmic pore structure index. 56d chloride diffusion coefficient has a good linear correlation with microcosmic pore structure index, and 84d chloride diffusion coefficient has a good nonlinear regression relationship with microcosmic pore structure index.

Abstract: Attainment of accuracy in raw materials mix for production processes has been the major problem in many production organizations in developing countries. Effects of unequal proportions of material required for a production process are not fully considered in the past studies. This study modeled the raw material requirements in a production process using proportionality based mixed linear programming approach. The objective was to find optimal mix of raw materials for the production of a unit tonnage of a product. The performance of the model was tested by comparing it with alternatively formulated model based on conventional material mix. This model was tested using a cement production system from which blasted limestone, crushed limestone; raw meal, gypsum, red alluvium, clinker and coal were used as raw materials. The conventional method of mixing materials led to 50 % surplus and shortage of materials in the process as compared with the new scheme. The model would be a good tool for accurate prediction of quantity of the raw material required in the production process.Nomenclature, the proportion of material used per ton of the processed product, the quantity of material in processed product (ton), the material proportional per ton of the product, andthe total quantity of materials needed per ton of the product,..., the counter for material type,..., the counter for material proportionality variant