GB372958A - Improvements relating to the treatment of nickel-copper solutions to remove iron present therein - Google Patents

Abstract

A process for the removal of iron from nickel salt solutions by hydrolysis in which the solution is first neutralized and then blown with air is characterized in that neutralization is effected by a strongly reactive metallic nickel product obtained by gas reduction of nickel compounds at low temperatures, preferably from 350-450 DEG C. Hydrogen or water gas are specified for the reduction. The nickel serves also to cement copper present. The process, which is effected below 60 DEG C., is of general application, but a special application is described, wherein nickel-copper matte is ground, roasted to remove sulphur and leached with acid for the partial removal of copper. Part of the leached residue is reduced under the specified conditions to obtain a nickeliferous metallic powder. The remainder is converted to metal and cast into anodes for use in an electrolytic cell, which is divided into cathode and anode compartments by a filter diaphragm, through which the electrolyte at about 50 DEG C. flows from the former to the latter. The solution escaping from the anode compartment is purified by the present process employing the nickeliferous powder obtained as above, and is returned to the cathode compartment. The exhausted nickeliferous material is mixed with the ground matte and re-used. The metals may be present as sulphate or chloride, and the electrolyte preferably contains a buffer, such as boric acid. Specification 185,859, [Class 1 (iii), Oxides &c., Metallic], is referred to.ALSO:A strongly reactive metallic nickel product, obtained by gas reduction, for example with hydrogen or water gas, of nickel compounds at low temperatures, preferably from 350 to 450 DEG C., is used to neutralize the acidity and to cement the copper present in nickel salt solutions below 60 DEG C. from which iron is subsequently removed by oxidation with air. In an application of the process, nickel-copper matte is ground, roasted to remove sulphur and leached with acid for the partial removal of copper. Part of the leached residue is reduced under the specified conditions to obtain a nickeliferous metallic powder. The remainder is converted to metal and cast into anodes for purification in an electrolytic cell. The electrolyte is purified employing the nickeliferous powder obtained as above. The exhausted nickeliferous material is mixed with the ground matte and reused. Specification 185,859, [Class 82 (i), Metals, Extracting &c.], is referred to.