Ultrasound-assisted oil removal of γ-Al2O3-based spent hydrodesulfurization catalyst and microwave roasting recovery of metal Mo.
Ultrasound-assisted oil removal of γ-Al2O3-based spent hydrodesulfurization catalyst and microwave roasting recovery of metal Mo.
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DOI：
10.1016/j.ultsonch.2018.05.023
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发表时间：
2018-12
影响因子：
8.4
通讯作者：
Lu Wang;Liu Chao;Wenwen Qu;Shengming Xu;Libo Zhang;Jinhui Peng;Xiaolei Ye
中科院分区：
文献类型：
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作者：
Lu Wang;Liu Chao;Wenwen Qu;Shengming Xu;Libo Zhang;Jinhui Peng;Xiaolei Ye
目前，加氢脱硫（HDS）废催化剂的主要处理工艺是焙烧-浸出，但焙烧-浸出过程中会产生镍钼钴（NiMoO 4或CoMoO 4）等杂质，不利于有价金属的回收。采用超声波-微波联合法对加氢脱硫废催化剂进行除油和回收钼的研究。首先，采用乙醇超声辅助提取MoNiCo/Al_2O_3催化剂的表面油。系统考察了温度、超声时间、液固比和超声功率对除油率的影响，并采用响应面法优化了工艺条件。结果表明，在温度55 °C、超声时间2 h、液固比5：1、超声功率600 W的最佳条件下，除油率可达99%以上。除油后，将样品在微波场中在500 °C下焙烧15分钟。最后采用碳酸钠（Na 2CO 3）溶液对焙烧后的样品进行超声浸出，回收钼。微波焙烧后脱油样品中钼的萃取率达到94.3%，比含油样品中钼的萃取率提高约7个百分点。此外，微波焙烧法对含油和脱油废催化剂的钼提取率均高于传统方法。结果表明，超声-微波辅助法可显著提高钼的回收率，并大大缩短处理时间。
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 (NiMoO4or 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/Al2O3catalyst 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 °C, ultrasonic 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 °C for 15 min. The generation of toxic gas could be effectively avoided and no hardest-to-recycle impurity CoMoO4was 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.