Abstract
This paper examines energy-efficient and environmentally friendly methods of processing technogenic gold-bearing raw materials. The main focus is on studying the kinetics of the thiourea leaching process after the preliminary oxidative roasting of gold-bearing materials obtained from technogenic waste from a gold extraction plant. This study compares traditional roasting in an electric furnace with roasting in a chemical reactor with microwave treatment. Preliminary oxidative microwave roasting was found to achieve a higher thiourea leaching reaction rate due to better exposure of refractory gold. Compared to traditional oxidative heating, roasting in a microwave-assisted chemical reactor reduces processing time and energy consumption while improving the degree of preparation of the raw materials for subsequent gold leaching and increasing gold recovery by 17.8%. This reduction in activation energy is due to preliminary oxidative roasting with microwave treatment (P 1.1 kW, frequency 2.45 GHz, 700 °C for 10 min), which results in an energy reduction of 14.716 kJ/mol versus 22.630 kJ/mol for traditional oxidative roasting in an electric furnace (750 °C for 60 min).