Decomposition of Magnesite-Sparing Waste in Sulfuric Acid with a High Concentration: Empirical Modeling and Determination of Optimal Conditions

This article describes the processes of decomposition of magnesite waste in sulfuric acid, which is formed during flotation enrichment of the Zinelbulak talc-magnesite deposit. As a result of the research, the influence of concentration and temperature of the reaction medium on the dissolution of magnesite in H₂SO₄ solution was investigated and melting degrees were determined. Based on the data obtained, a mathematical model of the process was formed: the melting kinetics were described by equations, and the parameters were calculated using regression analysis. The modelling results were based on the rate at which magnesite melts, mainly acid concentration, and temperature factors were studied. The value of the coefficient of determination of the constructed mathematical model justified the fact that this model was 97.2% accurate. Based on the reliability of the mathematical model, optimal conditions are determined through experimental and model analysis. The optimum conditions are a temperature of T = 81.45 °C and an acid concentration of C = 74.05%, resulting in a decomposition rate of Ymax = 93.57%. The results of this work establish a scientific foundation for treating waste products containing magnesium and producing products such as magnesium sulfate from them. Initially, the article describes the composition of raw materials and experimental methods, then the mathematical model and the results obtained are analysed, and conclusions and proposals are presented.