Raw Material Firing Research Articles

Concrete manufacturing with a low CO2 footprint

The object of the research is the current state of the climate action strategy for cement and concrete production, including possible levers for reducing CO2 emissions. It has been determined that the main source of carbon dioxide emissions per tonne of Portland cement, and subsequently per cubic metre of concrete, is the decarbonization of calcium carbonate, the main raw material component of Portland cement clinker. It also involves the combustion of fossil fuels, which are necessary for the decarbonization and firing of raw materials. Therefore, Portland cement with a reduced content of Portland cement clinker is considered as a solution for concrete manufacturing with a low CO2 footprint. Additionally, the potential of Ukraine in the development of a sustainable Portland cement clinker production approach based on using alternative fuels and alternative raw materials, which will positively affect the total amount of CO2 per ton of clinker, was evaluated. Improved quality performance of cement has been identified as a key direction in product portfolio management to promote cements with a lower clinker factor by increasing the content of active mineral additives. It is shown that the production of concrete with increased strength and durability requirements based on cements saturated with active mineral additives is an important task. Since active mineral additives have different origins, not all of them available for use in cement production exhibit hydraulic properties inherent in Portland cement clinker. Was investigated that «Complex Performance Testing System» (CPTS) as the main test method for evaluating the quality parameters of Portland cement with a reduced clinker factor in accordance with specific applications. This customer-oriented approach opens up the possibility of producing low-CO2 concrete. It has been shown that using the CPTS method, a reduction in the total amount of cement per cubic meter of concrete can be achieved, given the specified parameters of the concrete mix, which has a direct impact on the total amount of CO2/m3.

Quantitative Estimation of Mullite in Alumina Based Porcelain Insulators Samples

Although porcelain insulators in power lines have been in use for decades, several undergo catastrophic failures while early in service. A study addressing the materials aspects has been conducted on alumina based porcelain insulators. Apart from their electro mechanical stability characteristics, material aspects like composition, phase and microstructure play a very important role in their performance. The qualitative phase analyses on the insulator samples give an idea about the different major and minor phases present. Attempts have already been made to estimate α alumina and α quartz content in porcelain body. Mullite is another important phase present in the porcelain body, which gets formed during firing of raw materials during insulator manufacture and which has not been estimated quantitatively. An attempt has been made here to assess the mullite content in the alumina based insulator samples by X-Ray diffraction quantitative analysis. Internal standard method of quantification has been adopted successfully for the analysis. This article describes the quantification of mullite phase by the internal standard method based on X-Ray diffraction principle.

Rehydroxyiation of clay minerals and hydration in ancient pottery from the ‘Land of Geshur’

Rehydroxylation of clay minerals and hydration in Bronze and Iron Age pottery from the ‘Land of Geshur’ (east of the Sea of Galilee), were investigated by IR thermospectrometry. A weak OH band, which resembles those in smectite or illite, exists in most samples, but it is masked by the water bands at lower temperature. Two types of transformation of clay minerals occur during firing of raw materials, reversible and nonreversible dehydroxylation, taking place at a relatively low and high firing temperatures, respectively.Clay minerals rehydroxylate and reconstruct after relatively higher firing temperatures in noncalcareous raw materials than in calcareous ones. These processes take place after higher temperatures in cooking pots made from the former type of raw material as compared with storage and table-ware vessels made from the latter.The absorbed water in the pottery is mainly connected with the dominant X-ray amorphous matter formed by the firing process.