METHOD OF PRODUCING NICKEL SULPHATE Russian patent published in 2025 - IPC C01G53/10 C22B7/00 C22C1/08 

FIELD: metallurgy.

SUBSTANCE: invention relates to non-ferrous metallurgy, particularly to production of nickel sulphate from nickel metal. Method involves electrochemical dissolution of cathode scrap formed during production of primary nickel in anode baskets at current density of 50 to 1,000 A/m² in electrolyte, which is a solution of sulphuric acid in water with concentration of 50 to 400 g/dm³ in electrolysis bath. Crystalline nickel sulphate is deposited from the electrolyte by evaporation and crystallisation and the return electrolyte is returned to the head electrolysis operation simultaneously with replenishment with sulphuric acid to the initial concentration. Electrolyte is removed from the electrolysis bath at a residual concentration of sulphuric acid of not less than 10 g/dm³ to increase the extraction of nickel sulphate and reduce the solubility of nickel sulphate. Gaseous hydrogen released on cathodes is forcibly diluted by inflow of fresh air to safe concentration of not more than 0.4 % of volume.

EFFECT: recycling of substandard primary nickel with production of pure crystalline nickel sulphate with no harmful emissions into atmospheric air, discharges into industrial sewage system and natural water bodies, formation of hazardous wastes.

3 cl, 7 dwg