Research on the recycling of valuable metals in spent Al_2O_3-based catalyst

摘要

A new technology was developed to recover multiple valuable elements in the spent Al_2O_3-based catalyst by X-ray phase analysis and exploratory experiments. The experiment results showed: In the condition of roasting temperature of 750 deg C and roasting time of 30 min, mol ratio of Na_2O: Al_2O_3 1.2, the leaching rate of alumina, vanadium and molybdenum in the spent catalyst is 97.2 percent, 95.8 percent and 98.9 percent, respectively. Vanadium and molybdenum in sodium aluminate solution can be recovered by barium hydroxide and barium aluminate, the precipitation rate of vanadium and molybdenum is 94.8 percent and 92.6 percent. Al(OH)_3 is prepared from sodium aluminate solution with carbonation decomposition process, and the purity of Al_2O_3 is 99.9 percent after calcinations, the recovery of alumina can reach 90.6 percent in the whole process. The Ni-Co concentrate was leached by sulfuric acid, a nickel recovery of 98.2 percent and over 98.5 percent cobalt recovery was obtained respectively under the experimental condition of 30 percent (w/w) H_2SO_4, 80 deg C, reaction time 4 h, liquid:solid ratio (8:1) by weight, stirring rate of 800 rpm.