METHOD OF PURIFICATION OF SULPHATE SOLUTIONS OF NON-FERROUS METALS FROM IRON Russian patent published in 2009 - IPC C22B3/44 C22B15/00 C22B19/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to hydrometallurgy of non-ferrous metals, in particular to purification of sulphate solutions containing non-ferrous metals from iron. The method involves neutralisation of the acid with limestone or lime which is followed by oxidation and hydrolytic precipitations of iron by means of oxyhydrolysis in the autoclave at elevated temperatures and pressure of oxygen. At the same time the pulp obtained after neutralisation is subjected to oxyhydrolysis. This pulp contains crystals of gypsumserving as solidification centers and ensuring precipitation of iron as macrocrystalline well filtered sediment. The neutralisation is performed from the solution containing 15-20 g/l of sulfuric acid minimum till pH 0.5-2.5. The oxyhydrolysis is performed at the temperature of 160-200°C and the oxygen partial pressure of 0.3-1.0 MPa (3-10 atm).

EFFECT: minimum amount of the filter equipment and better extraction of the non-ferrous metals with iron-containing sediment because of the iron extracted as well filtered sediment.

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