Currently, roasting-leaching is the main treatment process of spent hydrodesulfurization (HDS) catalyst , but it will produce impurities, such as nickel molybdate and cobalt molybdate (NiMoO₄ or CoMoO₄), which is adverse to recover valuable metals. In this paper, a combined ultrasonic-microwave method was developed to remove oil and recover molybdenum (Mo) from the spent HDS catalyst. Firstly, ethanol was used to extract the surface oil of the spent MoNiCo/Al₂O₃ catalyst with ultrasonic assistance. Effects of temperature, ultrasonic time, liquid-solid ratio and ultrasonic power on the oil removal rate were investigated systematically and the process conditions were optimized using response surface methodology (RSM). The results showed that the oil removal rate was over 99% under the optimum conditions of temperature 55 ^oC, ultrosonic time 2 h, liquid to solid ratio 5: 1, and ultrasonic power 600 W. After oil removal, the sample was roasted in microwave field at 500 ^oC for 15 min. The generation of toxic gas could be effectively avoided and no hardest-to-recycle impurity CoMoO₄ was found. At last, the roasted sample was subjected to ultrasonic leaching with sodium carbonate (Na₂CO₃) solution for recovering Mo. Extraction of Mo of the deoiled sample after microwave roasting reached 94.3%, which is about 7% higher than that of oily sample. Moreover, microwave roasting method resulted in a much higher Mo extraction than traditional method for both the oily and deoiled spent catalyst. It was concluded that the ultrasonic-microwave assisted method could remarkably improve the recovery of Mo and greatly shorten the processing time.

目前，焙烧浸出是废加氢脱硫（HDS）催化剂的主要处理工艺，但会产生杂质，如钼酸镍和钼酸钴（NiMoO ₄或CoMoO ₄），这不利于回收有价值的金属。在本文中，开发了一种组合的超声波-微波方法以去除油并从废HDS催化剂中回收钼（Mo）。首先，用乙醇提取废的MoNiCo / Al ₂ O ₃的表面油。超声辅助催化剂。系统地研究了温度，超声时间，液固比和超声功率对除油率的影响，并采用响应面法（RSM）对工艺条件进行了优化。结果表明，该油除去率为99％以上的温度55的最佳条件下^ø C，ultrosonic时间2小时，液固比5：1，和超声功率600除油W.后，将样品在烤微波场在500 ^o C持续15分钟。可以有效避免有毒气体的产生，并且没有发现最难回收的杂质CoMoO ₄。最后，用碳酸钠（Na ₂ CO₃）用于回收钼的溶液。微波烘烤后，去油样品中钼的提取率达到94.3％，比油性样品高约7％。而且，对于油性和脱油的废催化剂，微波焙烧方法导致的钼提取量比传统方法高得多。结论是，超声-微波辅助法可显着提高Mo的回收率，并大大缩短了处理时间。