Mathematical Models for an Energy Intensive Multistage Roasting Process of Pelletized Industrial Waste from Apatite-Nepheline Ores

Abstract

In this article, we describe mathematical and computer models for the complex, energy-consuming, multistage, integrated chemical and power engineering processes of calcination and sintering of pelletized industrial waste from apatite-nepheline ores, accumulated in the dumps of mining and processing plants. The models take into account the negative effect of vitrification and the subsequent destruction of pellets in case the operating temperature condition in the high-temperature roasting zone of indurating conveyor furnaces is violated during the implementation of these thermally activated processes. Experimental and analytical methods have been developed for the analysis of integrated, thermally activated processes in a dense multilayer mass of pellets obtained from apatite-nepheline ores waste, taking place in indurating furnaces. The possibility of complex phenomena accounting for polymorphic transformations, chemical reactions in solid phases, reactions involving a liquid phase, as well as the formation of new phases and solid solutions as a result of reactions, must be considered when modeling these processes. This analysis makes it possible to increase the strength of pellets during sintering and the degree of calcination as a result of carbonates dissociation, as well as to detect and use the potential of increasing energy and resource efficiency in a complex, environmentally safe, chemical and power engineering system for the processing of industrial waste of apatite-nepheline ores from dumps of mining and industrial plants.