NON-FERROUS AND RARE METALS EXTRACTION FROM CONCENTRATES AND SLAGS
The technology of heap and underground leaching of copper ores was developed and introduced. The kinetic studies of copper and zinc minerals dissolution preceded the technology development. Operating conditions were found and the intensification of mineral dissolution was defined. The optimum conditions of leaching different commercial-genetic types of ores were developed. Tens of thousands tons of copper were produced in the periods of test and commercialization. The optimum conditions of vat and heap leaching oxidized nickel ore (ONO) were developed. The present ONO shaft smelting is detrimental ecologically and economically ineffective. This leads to plants closure. The solutions of 1-3 Ni; 0.2 Со; 20-40 Mg g/dm <sup>3 </sup>were produced by heap leaching. Both Nickel as a product of increased purity and concentrates of Mn and Mg were extracted from solutions. The exploratory studies of ecologically clean technology of Mo and Re extraction from sulfide concentrates were performed. In the present technologies SO <sub>2</sub> is gassed during oxidized roasting, and Mo and Re are partially lost with gases and solid residues after cinder leaching. In the new technology the concentrate with CaO is roasted. The cinder with CaSO <sub>4</sub>, CaMoO <sub>4</sub>, Ca(ReO <sub>4</sub>) <sub>2 </sub>is produced without SO <sub>2 </sub>gassing and without Mo and Re losses. Mo and Re are extracted selectively with an end product in result. Vanadium pentoxide of improved purity, useful for alloying of titanium alloys, is not produced in Russia. The technology of V <sub>2</sub>O <sub>5 </sub>and Mn <sub>3</sub>O <sub>4</sub> produce from manganese vanadium slags is worked out. Slags are roasted with no addition of Ca and Na. The cinder contains Mn <sub>2</sub>V <sub>2</sub>O <sub>7</sub>, from which vanadium is selectively recovered in soda solution, and Mn is recovered in acid one. Vanadium pentoxide containing 99.6-99.8 mass % of basic substance is obtained. Solid residues are smelted and complex ligature is produced