ES321567A1 - Process of manufacture of pure nickel hydrate. (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Process for manufacturing pure nickel hydrate, characterized in that it comprises the steps of: anodic corrosion of nickel matte anodes having, by weight, a nickel content of 76% to 83%, of sulfur of 23% to 16% %, cobalt from 0.30% to 0.40%, iron from 0.04% to 0.08%, copper from 0.050% to 0.065%, by direct electrolytic action in the anodic compartments of an electrolysis cell compartmentalized containing as electrolyte an aqueous solution of a chloride or sulfate, soluble in water, of an alkali metal or alkaline earth metal, such as, particularly sodium, potassium, magnesium and calcium, to form an anolyte rich in nickel chloride or in nickel sulfate, in an acidic medium of pH from 2 to 4; a diffusion of the anolyte into the cathode compartments of the electrolysis cell through the fabrics separating the anodic and cathodic compartments; a precipitation of the nickel in the cathode compartments in the form of nickel hydrate, in a basic medium with a pH of 8 to 10; a continuous extraction, outside the electrolysis cell of the nickel hydrate suspension in the electrolyte; a decantation of this suspension in a static decanter which allows the suspension to be concentrated from 4 to 6 grams of nickel per liter to 25 to 30 grams of nickel per liter; and a series of filtrates of the concentrated suspension with washes with water of the nickel hydrate on filters and by agitation in repulping, comprising three stages of filtering, and washing with water on a filter and two intermediate repulping. (Machine-translation by Google Translate, not legally binding)