Technologies and Technical Means for Electrosorption Leaching of Gold From Flotation Tailings of Resisting Sulfide Raw Materials

Abstract

Relevance. The problem of expanding the raw material base of the gold mining industry is becoming more pressing due to the depletion of explored reserves, rising production costs and the costs of minimizing the man-made impact on the environment. With the depletion of oxidized gold-bearing ores, finely disseminated ores are increasingly being involved in processing. An increase in gold production volumes can be achieved by improving the beneficiation process. An alternative to traditional beneficiation technologies is electrotechnologies that use the phenomenon of energy impact on mineral raw materials. Among them, the range of application of the resin-in-pulp electrosorption leaching technology is expanding. Objective. Justification of technologies and technical means for electrosorption leaching of gold from flotation tailings of refractory sulfide raw materials. This will increase metal production and strengthen the mineral resource base of gold mining enterprises and reduce damage to the environment. Methodology. A comprehensive method was applied, including analytical studies using the fundamentals of system analysis and mathematical statistics, technological experimentation using mathematical planning of experiments, economic and mathematical modeling, technical and economic calculations and pilot industrial implementation. Laboratory studies were modeled on the tailings of flotation enrichment of gold from the flotation tailings of refractory sulfide raw materials. The application of electric fields was provided by two parallel electrodes. Scientific novelty. Theoretical and technological experimentation, substantiation of fundamentally new technologies and technical means of electrosorption leaching of gold from flotation tailings of refractory sulfide raw materials. Results. The efficiency of using technogenic resources is achieved by combining traditional enrichment technologies with the capabilities of hydrometallurgy and electrochemistry. Flotation tailings of ores with gold content from 1.0-1.5 g/t are leached according to the scheme: granulation to a size of 15-30 mm with the addition of 1 g/l of cyanide, sulfuric acid removal of metals, alkaline treatment to pH 10-11, cyanidation with an irrigation density of 20 l/m2 per hour, gold sorption on anion exchanger, anion exchanger regeneration and regenerate electrolysis. Gold leaching from refractory sulfide raw materials is possible after the destruction of sulfides upon reaching an oxidation potential of 1000 mV, it effectively proceeds in a solution of 20-30% sodium chloride upon application of direct electric current with a density of 800-1200 A/m2, pH of the medium 2.0-4.0 and a temperature of 60-800 C with the extraction of up to 70-80% of gold into the solution with an electric power consumption of 120-220 kW/t. The results of the experiment confirm the efficiency of the technology of electrosorption leaching of gold from gold-bearing pulps. The leaching rate increases by 25-30%, the sorption capacity of the anionite AM-2B increases by 2.5-3 times. An increase in the capacity of the sorbent and a decrease in the amount of gold in the liquid phase shifts the equilibrium of the system towards gold dissolution and intensifies the volume and completeness of its extraction. Implementation. The technologies of electrosorption and electrochemical leaching of gold from ore flotation tailings have been tested and recommended for industrial development at the Aksu, Bestobe, Zholymbet deposits and implemented in the practice of ABS-Balkhash, Kazakhaltyn JSC (Republic of Kazakhstan) and can be recommended for other developed mining and gold mining countries of the world.