Study of properties of dusty wastes from power generating plants of Ukraine

Abstract

Introduction. Disposal of recycled materials is targeted at saving the natural resources and reducing the volume of wastes that have to be disposed of in special landfills. Disposal is encouraged by many countries of the European Union. A key element in promoting of wastes recycling is the «polluter pays» principle, which has been included in all Community directives regarding management of safe and hazardous wastes. In order to encourage recycling, many Member States have adopted specific environmental legislation, in particular, the wastes disposal tax.Problem statement. Today, in Ukraine the issue of utilization of industrial wastes has not been solved, that is why a considerable part of them are in the dumps and pose a great risk for the environment; and only a small part of them is utilized in the construction projects [1], although there exists the «State Target Economic Program for the Development of Public Roads of National Significance for 2018–2022» [2] and the Order of the Cabinet of Ministers of Ukraine [3] which regulate the use of local materials, including industrial waste during the construction of motor roads. At the same time, millions of tons of dusty wastes are being produced at the Ukrainian power plants as a result of coal combustion — fly ash and ash from a tailings dam.Purpose. Carrying out of research of ash from a tailings dam and a mixture of limestone material with the ash from the tailings dam on conformity with the requirements to fillers.Materials and methods. The ash from a tailings dam, a mixture of limestone material with the ash from a tailings dam and commercially produced limestone filler have been selected for the study.Results. The results of the research on establishing the possibility of using the dusty waste products from power generating plants for the production of asphalt mixtures are presented. Experimental studies have been performed to determine the physical and mechanical properties of the ash from the tailings dam with partial replacement by limestone material. The conformity of the studied materials to the requirements of national standards was determined.Conclusions. Studies for determination of grading, porosity, swelling and structuring ability showed that the tested ash does not meet the requirements of Table No.5 of DSTU B V.2.7-121 for porosity in the case of compaction of 40 MPa; a mixture 80:20 — for swelling of samples of the filler with bitumen; and the mixture 50:50 meets the established requirements by defined indicators. A significant swelling increase of the samples from the mixture of filler with bitumen may be the result of high content of clay impurities in the test materials.Keywords: industrial wastes, limestone material, ash, filler. physical and mechanical properties.