Single-stage production of the nickel concentrate with processing of the rhenium-containing refractory alloy

Abstract

The results of electrochemical processing of the ZhS32-VI refractory alloy in nitric acid solutions are discussed. The main production idea involves the performance of an electrochemical process under the controlled value of the anodic potential. This procedure provides the preferential transfer of nickel, which is the alloy base, into the solution and the formation of the cathodic product or metallic nickel with a purity no lower than 95%. Experiments on the electrochemical dissolution of the mentioned alloy at various values of the anodic potential are performed. It is determined that the cathodic product contains at Ea = 1.05 V, %: Ni 94.9, Re 0.2, Co 4.7, and Cr 0.1. It is established that the incorporation of the chloride ion (20 g/L) into the nitric acid electrolyte exerts no substantial effect on process characteristics; notably, the amount of nickel in the anodic slime decreases from 2.4 to 1.6%, and no considerable increase in the nickel content in the cathodic product takes place. The exclusion is a considerable increase in the transfer rate of rhenium into the electrolyte; notably, the rhenium concentration in the nitric acid electrolyte after the 10-h production process is 1.26 g/L, and that in the nitric acid electrolyte with the addition of the chloride ion is 8.90 g/L. It is shown that the process performance of the electrochemical dissolution of Re-containing nickel-based refractory alloys under the controlled anodic potential Ea = 1.05 V in nitric acid electrolytes provides the formation of a nickel concentrate with a purity no lower than 95% in one stage and makes it possible to concentrate rhenium in the anodic slime.