Efficiency of Ozone Application for Extraction of Metals from Mineral Raw Materials

Abstract

The results of studies on the use of ozone for the extraction of nonferrous, rare, and noble metals from ores, enrichment concentrates, and technogenic raw materials, identified from world scientific publications and in patent literature since the beginning of the 20th century, are summarized. Ozone is a strong oxidizing agent, the oxidation potential of which is 1.5 times higher than the potential of chlorine in an acidic environment. With the participation of ozone, even resistant metals and minerals are dissolved. The use of ozone for the extraction of metals from mineral raw materials is not accompanied by contamination of processed products and the formation of hazardous waste. A significant number of studies have been presented on the use of ozone to dissolve gold and other noble metals in mineral acids, showing an increase in the extraction of metals into solution. Cyanide and thiocarbamide leaching of gold from mineral raw materials by replacing oxygen with ozone have been studied. The results of vat and heap leaching of nonferrous and noble metals using ozone obtained by irradiation of air or oxygen with ultraviolet light, in particular, using photoelectrochemical treatment, are presented, on the basis of which new technologies are patented. An assessment of the effectiveness of ozone application for flotation enrichment of mineral raw materials, purification and detoxification of solutions and solid products of metallurgical processing, regeneration of other oxidizing agents, and extraction of metals from technological solutions is given. The results of studies on the use of ozone for vat leaching of metals from refractory sulfide ores and sulfide enrichment concentrates in acid solution, as well as the study of the kinetics of oxidation with the participation of ozone of sulfide minerals of copper, iron, zinc, and molybdenum, are summarized. The results of using a combination of ozone with other oxidizing agents—hydrogen peroxide and iron(III) ions—for the extraction of metals from sulfide mineral raw materials in a sulfuric acid solution are presented and analyzed. According to the results of most studies, it can be concluded that the use of ozone is effective for the extraction of metals from mineral raw materials: the technological parameters of the processes increase (extraction of metals into solution, selectivity of the extraction of metals from complex raw materials) and the duration of processing decreases.