Recovery of the metals contained in spent catalysts using a thermal treatment followed by a selective chlorination

Abstract

An experimental procedure for the recovery of the metallic values contained in spent catalysts, such as cobalt, chromium, copper, nickel, molybdenum, titanium, vanadium, tungsten, etc. is described. The procedure is based both on a thermal treatment carried out prior to another one performed at 600 °C and on the selective chlorination of the samples, using different gaseous mixtures, at a temperature between 300 and 600 °C. From the chlorination residues, and as chlorides, it is possible to recover up to 98 % nickel, cobalt molybdenum, titanium and tungsten and 80 % of the vanadium compounds contained in the condensation products. The oxygen partial pressure in the gaseous mixture seems to be a determining factor in the chlorination selectivity.