Use of Ash and Slag Waste from Thermal Power Plants as an Active Component of Building Materials

Abstract

This paper presents the use of ash and slag waste generated from the combustion of coal at thermal power plants as a secondary raw material in various areas of industry. The process of separation of ash and slag is considered into the following components: coal, magnetic concentrate, and aluminum silicate concentrates. The possibility of using aluminum silicate concentrate in the building industry for the production of mineral binders and premixes is investigated. Mineral binding compositions based on gypsum were studied by thermogravimetric methods (differential scanning calorimeter DSC Q2000, thermogravimetric analyzer TG 209 F1). The influence of aluminosilicate microspheres on the quality of the building material was evaluated. The introduction of aluminosilicate concentrate into the building composition reduces the moisture content by 1 %, but the weight loss profile does not change. This indicates the redistribution of microspheres in the volume of the mineral binder composition and the formation of a new physical phase. When using a superplasticizer (Melflux 1641F1), the mechanism of water loss (additional peak) changes. There is a change in the formation of phase contact in the condensed system.