Development of the New Method for Oxidized Nickel Ore Processing

In modern conditions of sharp fluctuations in nickel prices on world markets, the problem of profitability of processing Russian poor oxidized nickel ores (ONO) has arisen. As an alternative to the previously existing in Russia, a sulphidation-reducing smelting on a matte, a hydro-pyrometallurgical method has been proposed for the preparation of complex nickel-, chromium-, manganese-containing ferroalloys. At the first stage, hydrolytic precipitation (with sodium hydroxide) is considered as a method of processing production solutions from heap leaching of ONO. It is established that at pH = 5.5, Al is completely removed in the precipitate as hydroxide. After washing from impurities and calcining, a concentrate containing 50 wt.% Al was obtained. At the second stage, at pH = 9.5, more than 99% of nickel and cobalt oxides, as well as 92% oxide concentrate contains, by weight. %: 67 NiO; 3 CoO; 20 MnO; 9 MgO; 0,2 S. At the third stage, a pyrometallurgical method for smelting complex ferroalloys of the Fe-Ni-Cr- Mn-Si system using refractory ferrosilicochrome as a reducing agent is proposed for the processing of nickel-containing concentrate. The scheme of hydro pyrometallurgical method of ONO processing includes: crushing, heap leaching, hydrolytic precipitation to obtain an aluminum-cobalt and nickel concentrates, silicothermic smelting to obtain complex nickel, chromium, manganese ferroalloys, for smelting of suitable stainless steels. Keywords: oxidized nickel ores, nickel, cobalt, manganese, leaching, precipitation, roasting, metallotherm