Processing mineral raw materials in Siberia: ores of molybdenum, tungsten, lead and gold

Problems related to the processing of mineral raw materials from Siberia (i.e. molybdenum-, tungsten-, lead- and gold-containing ores and concentrates) are reviewed. It is shown that hydrometallurgical methods for processing such raw materials are more advantageous than pyrometallurgical ones. For example, hydrometallurgical treatment of molybdenum and tungsten concentrates can be used industrially. Studies have shown that the recovery and concentration of molybdenum and tungsten from leach solutions can be effectively carried out using macroporous anion exchangers. Other studies show that nitric acid/iron(III) solutions are most efficient for leaching lead from lead sulfide concentrates. Metallic lead as well as lead-containing compounds can be produced by electrolysis of lead nitrate leach solutions. These solutions also provide a hydrometallurgical method for the oxidation of pyrite and arsenopyrite in gold-containing raw materials prior to the recovery of gold by complex-forming reactants. Salt decomposition of sulfides and dissolution of gold by non-cyanide complex-forming reagents can be used also for the recovery of gold from refractory arsenopyrite concentrates. Hydrometallurgical technologies recover about 93–98% of metals. Moreover, it is quite easy to improve production efficiency by modifying the design of the industrial equipment and by preventing the formation of environmentally harmful products.