Papers by Keyword: Clinker

Abstract: Mortar is another construction medium made of cement, which is mixed with sands and water, and lime is applied to increase the product's longevity. The gypsum renders workability to make mortar or concrete by keeping the cement in plastic state at early age of hydration. The gypsum is called the retarding agent of cement because the gypsum which is mainly used for regulating the setting time of cement. To get the optimal setting time for optimum compressive strength, gypsum in the cement needs to be control. Cement setting time when it hydrates and renders cement paste when combined with water. The objective of this research is to analyze the effect of different amount in Ordinary Portland Cement (OPC). Vicat apparatus was used to analyze the initial setting time of cement paste. Gypsum and clinker were used in production of mortar with the size 50 mm x 50 mm x 50 mm. This research deals with observation of the cement setting time to point out some differences that would effect to strength of mortar. The results reveal that control gypsum with 4% of gypsum has the highest strength as compared to 0% of gypsum and 8% of gypsum. The setting time of cement paste are discussed with respect to their influence on the strength of mortar.

Abstract: Red mud (RM) is an industrial waste obtained from the Bayer process which is usually discharged into marine or disposed into a landfill causing pollution for the surrounding water, air, and soils. Thus, disposal of RM is an environmental concern, and it should be recycled effectively. Because RM consists of iron- and aluminum-rich phases, it is possible to be processed into cementitious material and utilized for construction purposes. This research fabricated a type of cement from the mixture of RM and limestone. The mixture was sintered at temperature of 1180 °C to obtain the clinker of the novel hydraulic cement with C₂S, C₃A, and C₄AF minerals. In which, C₂S, C₃A, and C₄AF are respectively belite, alite, and tetra-calcium aluminoferrite compounds that are characteristic hydraulic minerals of Portland cement clinker. The specifications of this cement were tested and evaluated in this study such as chemical and mineralogical compositions, fineness, specific surface area, mechanical strength after 3, 7, and 28 days.

Abstract: Grinding aids to increase grinding efficiency in cement production are materials that can produce large amounts of high-quality cement in a short time by reducing surface energy by preventing particle agglomeration and improving fluidity. In the paper, a grinding aid using glycerol-waste antifreeze(GAP) is prepared and its effect on the grinding properties of clinker is investigated in contrast to that without the grinding aid. The results are as follows: The angle of repose of the cement powder added with GAP decreases as the grinding time increases (decreases by 3.8° when the grinding time is 60 minutes), indicating that it increases the flowability of the powder. On the contrary, the residual amount of 45µm sieve is also significantly reduced (4.6% decrease) and the specific surface area increases (30.5m²/kg), which results in an increase in the grinding efficiency. In the size range of 3 to 32µm, it increases the particle content, makes the particle size distribution uniform, the 7d and 28d activity index of the powder is improved by 5% and 6%, respectively, and increases the compressive strength of the cement. In addition, it is confirmed that the performance of the TEA grinding aid and the grinding aid are similar, and are very effective in terms of economy.

Abstract: The aim of the work is to study the microfiller effect on the granulometric composition of the modified cement. A scanning electron microscope RМ-106 I was used for microscopic analysis. The survey was carried out in reflected electrons. The chemical analysis of the materials’ structure was investigated by energy dispersive spectroscopy (EDS). The distribution of particles of mineral components was evaluated with a Microsizer 201C laser particle analyzer with a range from 0.2 to 600 μm. Microscopic analysis of the samples of microsilica MK-85 shows that all particles are spherical with an average grain size of about 5 microns and consist of amorphous glass with a different set of particle fractions. The results of X-ray phase analysis of condensed microsilica grade MK-85 show that it consists mainly of silicon dioxide in an amorphous form. The introduction of mineral additives with a high specific surface in the composite Portland cements composition in an amount of more than 5% is not rational without the use of superplasticizers, since the water demand increases sharply, which reduces the cement stone strength. The introduction of a microfiller provides an increase in the compressive strength of a cement stone at the age of 28 days of normal hardening by an average of 37%.

Abstract: Several parameters affect the properties of Portland cement and one of these parameters is the cooling rate of the clinker. If the effectiveness of the cooling method of the clinker increases, a good enhancement in the properties of Portland cement will be found. Depending on the new cooling method suggestion by Nasr et. al. [20], the counter pattern of air clinker flow was studied using (FLUENT 6.3.26). The dimensions of the cooling room in grate cooler, the constant mass flow rate of both clinker and air, different height ratios, and different clinker porosity were considered in this numerical work. The results show that the heat transfers in the first half of the cooling room (0 < X < 0.9 m) is larger than that in the second half (0.9 < X < 1.8 m), and this leads to an increase in the temperature of outlet air so can benefits from it in the heating of furnace. When the clinker and air are flowing in the counter direction, the cooling method is more beneficial when compared with that of parallel flow because the exiting clinker has a great rate of cooler and the air exits from the grate cooler is loaded with large thermal energy. Finally, it can design the best length of gate according to the required clinker temperature at the outlet side, and this results to reduce the cost of the cooling process according to the temperature distribution results at (0 < X > 1.8m) for different porosity and H.R values.

Abstract: The carbonate components effect of raw materials - chalk and limestone on the clinker properties has been determined. Studies have been carried out on the raw mix these components partial replacement with the Oskol electrometallurgical plant slag in the amount of 10 and 20%. The maximum decrease in the carbonate component amount was 10%. The grinding clinker individual stages, characterized by the material destruction certain processes have been analyzed. It has been established that by reducing the chalk content in the raw mix and replacing it with the Oskol electrometallurgical plant slag, the clinker grindability is improved. The duration of grinding of such clinker is reduced by 22%. A decrease in the limestone amount in the raw mix and an increase in the Oskol electrometallurgical plant slag content does not affect the synthesized clinkers grindability.

Abstract: The study of the influence of selected temperature regime and potassium ions on the process of synthesis of belite (2CaO·SiO₂, C₂S) was carried out. The basic raw material was calcium carbonate (CaCO₃) and amorphous silica (SiO₂). The dosage of both components was based on the stoichiometric ratio of CaO:SiO₂ in belite. The modification of the raw meal was carried out in the form of potash, K₂O. Potash was dosed in the form of potassium carbonate, K₂CO₃, and potassium sulfate, K₂SO₄. The firing process was performed in a superkanthal furnace with two temperature modes, firing temperature: 1150 °C / 3 hours soaking and 1450 °C / 5 hours soaking. The evaluation performed by the experiment was based on mineralogical analysis by XRD analysis.

Abstract: Portland cement is the result of the calcination of a properly raw mix of limestone and clay, at high temperatures, and its manufacturing process is responsible for high environmental impacts, such as the exploitation of the deposits of these raw materials. In this context, the search for alternative raw materials becomes necessary. Thus, the present work analyzed the feasibility of the use of granite rock fines (GRF), waste generated in the process of production of aggregates for civil construction (gravel), aiming at the manufacture of Portland clinker. Firstly, the raw materials were characterized physically, chemically and mineralogically and, from these results, different raw mixes were prepared with different weight substitution of clay by the GRF (0%, 25%, 50%, 75% and 100%). Clinkers were produced from the calcination of the raw materials, and these were characterized mineralogically, in order to verify the optimal incorporation content of the GRF. Thus, it was possible to observe that the substitution of clay by GRF is technically viable and does not significantly interfere in the formation of mineralogical phases of Portland clinker.

Abstract: In this article the results of research to develop energy - and resource-saving technologies of production on local raw material base of the Ural Federal district of the white portland cement with high performance are represented. An x-ray phase analysis of the obtained building material is performed. The possibility of obtaining white portland cement-based pyrophillite mining waste,the composition of the raw mix for high-temperature synthesis of clinker white portland cement at low temperatures was studied. This reduces the costs for grinding of the mixture, and firing the clinker. The result of this work was the experimental batch of cement and studied all of its construction and technical characteristics.

Abstract: Pulp and paper mills have a process that generates waste with high levels of CaO and SiO₂, which can be valued as an alternative mineral source in the cement industry. In this work the lime mud, biomass ashes and WWTP sludge are used in the production of clinker. Analysis of X-ray diffraction (XRD) confirmed the crystalline phases calcite and quartz. Chemical analysis by X-ray fluorescence (XRF) identified Al₂O₃, CaO and SiO₂, providing support for the calculation of theoretical stages by applying the Bogue equations. Five formulations and three processing temperatures (1350, 1400, 1455 °C) were studied. The products obtained and an ordinary Portland cement (OPC) were characterized by XRD with quantification by the Rietveld method. The results showed that the processing conditions used produced belíticos (higher content of C₂S) and Portland (C₃S content greater) ecoclinker.