METHOD FOR PROCESSING OF OXIDISED NICKEL ORES Russian patent published in 2014 - IPC C22B23/00 C22B3/06 

FIELD: metallurgy.

SUBSTANCE: invention relates to a processing method of oxidised nickel ores. First, the prepared raw material is leached with nitric acid; the obtained pulp is filtered, thus separating it into a deposit and a filtrate. The deposit is subject to flushing and further magnetic separation with separation into silicone dioxide and an iron-containing fraction. The formed flushing waters are mixed with the filtrate and subject to two-stage neutralisation by water suspension of magnesium oxide so that iron hydroxide deposit is formed at the first stage, and metal hydroxide deposit and a solution of calcium nitrate and magnesium nitrate is formed at the second stage. The latter is subject to thermal hydrolysis so that nitric acid and magnesium oxide is formed. The deposit of metal hydroxides is treated with an alkali solution with release of a nickel-cobalt concentrate. Preliminary preparation of the initial raw material is performed by crushing and sieving, and when necessary, by enrichment as to nickel till content is at least 2.0 wt %.

EFFECT: effective extraction of nickel with a closed cycle of use of nitric acid and production of commercial products - a nickel-cobalt concentrate, magnesium oxide, silicon dioxide, an iron concentrate containing magnetite and iron-manganese spinels, iron-oxide pigments, calcium carbonate, a mixture of zinc, aluminium and chrome hydroxides.

5 cl, 1 dwg