PROCESS FOR PRODUCING NICKEL POWDERS FROM SPENT CATALYSTS

摘要

The invention relates to a process for producing nickel powders from spent catalysts. According to the invention, the process comprises the heat solubilization of the catalyst with HNO 3, the separation of acidic solution containing solubilized nickel and cooling the solution, then the precipitation at pH=4 ... 4.5 of the Al and Fe impurities with 10 % sodium carbonate, followed by the precipitation of the nickel carbonate at the pH=7 with 10 % sodium carbonate.The nickel powder is precipitated with hydrazine hydrate in excess of 20 ... 50 % in respect of the stoichiometrically necessary amount, after 3 ... 6 hours, being separated and treated with a 3 % HCl solution in a ratio of S/L=1/3 and then washed and dried. A product of a preponderantly polyhedral shape is obtained, said product having a density of 2.3 g/cm 3 and a minimum nickel content of 99.4 %, the process output ranging from 82 to 88 %.