GB1045630A - Method of producing pure nickel by electrolytic refining and product thus obtained - Google Patents

Abstract

<PICT:1045630/C6-C7/1> In a method of producing high-purity electrolytic nickel by electrolytic refining of ferro-nickel anodes 1, the anodes are electrolytically corroded in a nickel-chloride electrolyte 3 contained in the anodic compartment of a divided electrolytic cell 2 to form a high-nickel content anolyte containing impurities, which anolyte is then chemically treated outside the cell to yield a purified electrolyte which is fed into the cathodic compartment 7 of the electrolytic cell, which cathodic compartment comprises walls 10 of pervious cloth, nickel being electro-deposited from said catholyte on to the cathode 6, and the thus impoverished catholyte maintained at a higher level than the anolyte, flows through the pervious cloth walls 10 of the cathodic compartment back into the anodic compartment. The impure anodes used contain at least 80% nickel by weight. The nickel chloride anolyte contains 70-85 gr/1 of nickel, 30-60 gr/1 of calcium and 15-20 gr/1 of sodium, has a pH of about 4 and a temperature of 45-60 DEG C, whilst the catholyte from which iron, cobalt, copper, arsenic &c. have been removed during passage through purification cells 4, has a pH of 4 to 5 and a temperature of 50-60 DEG C. Stirring of the catholyte is effected by circulation thereof through the passages 8 and 12, and may be heated during circulation. The cathode may comprise a stainless steel mother plate, commercial nickel cathodes of thickness 1/4 " to 5/16 " being formed on either side, and later stripped therefrom; or may comprise a nickel mother plate 0.02" to 0.04" thick which forms an integral part of the commercial cathode which may then be 0.35-0.47" thick. The anodes may have a surface area from 2.15-13 square feet. The current density of electrolysis may range from 1500 to 4500 Amp/sq.ft.