New technique of comprehensive utilization of spent Al₂O₃-based catalyst

Abstract

A new technology was developed to recover multiple valuable elements from the spent Al₂O₃-based catalyst by X-ray phase analysis and exploratory experiments. The experimental results show that in the condition of roasting temperature of 750 °C and roasting time of 30 min, molar ratio of Na₂O to Al₂O₃ of 1.2, the leaching rates of alumina, vanadium and molybdenum in the spent catalyst are 97.2%, 95.8% and 98.9%, respectively. Vanadium and molybdenum in sodium aluminate solution can be recovered by precipitators A and B, and the precipitation rates of vanadium and molybdenum are 94.8% and 92.6%. Al(OH)₃ was prepared from sodium aluminate solution in the carbonation decomposition process, and the purity of Al₂O₃ is 99.9% after calcination, the recovery of alumina reaches 90.6% in the whole process; the Ni-Co concentrate was leached by sulfuric acid, a nickel recovery of 98.2% and cobalt recovery over 98.5% can be obtained under the experimental condition of 30% H₂SO₄, 80°C, reaction time 4 h, mass ratio of liquid to solid 8, stirring rate 800 r/min.