Determination of thermodynamic characteristics of chlorination of natural raw materials

The thermodynamic analysis of chlorination of the mineral part of the overburden carbonaceous rock of the Ekibastuz deposit (a natural multicomponent raw material) is of theoretical and practical interest. The nature of the change in the Gibbs energy value under the given conditions makes it possible to establish the fundamental possibility of the reaction. The assessment of the feasibility of each reaction is determined not only by the thermodynamic factor, but also by the rate of reaching equilibrium and the reaction rate. The calculated Gibbs energy and equilibrium constants characterizing the yield of the final reaction products in the temperature range of 400–2000 K show that in the presence of a reducing agent, the equilibrium of reactions is shifted towards the formation of chlorides. The effect of the reducing agent in the process of chlorination of oxide compounds is reduced to the binding of oxygen to form oxygen compounds of carbon. Thermodynamic analysis of systems (I–VII) showed that at a certain ratio of the initial components of the chlorination reaction at temperatures of 1000–1200 K passes through to the end with the formation of compounds in the gas and condensed phases, this is confirmed by the conducted research. Thermodynamic analysis of systems (I–VII) showed that a model based on theoretical calculations of the equilibrium compositions of reactions of chlorine with oxides, which are part of the mineral part of the carbonaceous rock, in the presence of a reducing agent, can be used to approximate the chlorination of aluminum-containing raw materials. Differences in the thermodynamic characteristics of the compounds that make up the carbonaceous rock, from a theoretical point of view, determine the fundamental possibility of selective chlorination of multicomponent raw materials. Ideally, a high degree of chlorination of aluminum oxide should be achieved with a minimum degree of chlorination of the accompanying oxides. The results of laboratory studies have fully confirmed the possibility of thermodynamic modeling of the chlorination process of multicomponent raw materials.