Development of Technology for Applying Sludge from Thermal Power Plants in the Production of Dry Plaster Mixtures

The article presents the results of experimental studies of authors on the development of compositions and technology for the production of dry plaster mixtures on the basis of fly ash of thermal power plants. This technology includes the production of slag binder by mechanochemical activation of blast-furnace granular slag with hardening activators and preparation of dry mixtures with the introduction of mineral, polymeric, reinforcing and air-entraining additives into their composition. The problem of accumulation in Kazakhstan of a significant amount of ash-and-slag waste from thermal power plants and their negative impact on all natural environments is highlighted. The grain composition of TPP wastes is briefly described, as well as the process of their formation. The results of studies on the effect of the addition of mechanically activated ash on the properties of plaster solutions are presented. Standard methods of research were used in the work, including technological methods, X-ray diffraction and chemical analysis of substances. For particle size distribution, the laser granulometry method was used. The test was carried out on the device "Microsizer 201A". Described are the compositions of dry plaster mixtures of M35 and M50 grades developed by the authors, the mineral part of which consists entirely of production waste and local raw components. The economic efficiency of the developed compositions of dry plaster mixtures, which is caused by the replacement of Portland cement with cheaper slag binder, is revealed. As a base of comparison, mixtures were chosen for Portland cement, used in plants of dry construction mixtures. Also, the environmental benefits of using the proposed method for processing ash and slag wastes, which consist in a significant improvement of the environmental situation in and around the TPP.