ABSTRACT

Disposal of spent catalyst in an economical and green way has become a great concern for industrial production. We developed a process including acid leaching, solvent extraction and stripping in order to recycle spent catalyst. In this study, we conducted selective recovery of molybdenum through focus on finding an optimized extraction and stripping process by comparing different extractants and stripping agents. To separate molybdenum from other metals efficiently and figure out the mechanism of extraction process, the five different extractants of methyl trioctyl ammonium chloride, tri-n-octylamine, tris (2-ethylhexyl) amine, bis (2-ethylhexyl) phosphate, and tributyl phosphate with different functional groups were examined; the extraction ability and extraction mechanism of these five extractants were systematically studied under the same system for the first time. It was found that more than 98% of the molybdenum could be extracted with an organic phase consisting of tri-n-octylamine or methyl trioctyl ammonium chloride under the optimal conditions. The result indicated that the tri-n-octylamine and methyl trioctyl ammonium chloride possess excellent molybdenum extraction ability, the extraction capacity of the rest extractants was in the order of bis (2-ethylhexyl) phosphate > tris (2-ethylhexyl) amine > tributyl phosphate. In the stripping process, NH₄OH, NaOH, and H₂SO₄ were chosen as stripping agent to strip the molybdenum from the loaded tri-n-octylamine organic phase. The stripping ability of the three studied stripping agents was in the order NaOH > NH₄OH > H₂SO₄. The Fourier transform infrared (FTIR) spectra showed that the structure of the tri-n-octylamine organic phase was stable during the extraction and stripping process. Results showed that molybdenum could be highly and efficiently recovered by optimized extraction and stripping process.

Implications: A series of different extractants and stripping agent have been systematically studied in order to compare their extraction and stripping ability under the same system. Based on the obtained results, an optimized extraction and stripping process was proposed to recycle molybdenum from spent catalyst efficiently. It is possible to dispose spent catalysts in an economic and environmental way by this developed metal recovery process.

摘要

以经济和绿色的方式处理废催化剂已经成为工业生产中的重要问题。我们开发了一种工艺，包括酸浸，溶剂萃取和汽提，以回收废催化剂。在这项研究中，我们通过比较不同的萃取剂和剥离剂，着重于寻找最佳的萃取和剥离工艺，从而进行了钼的选择性回收。为了有效地将钼与其他金属分离并找出萃取过程的机理，可以使用五种不同的萃取剂，分别是甲基三辛基氯化铵，三正辛胺，三（2-乙基己基）胺，双（2-乙基己基）磷酸酯和三丁基检查了具有不同官能团的磷酸盐；首次在同一系统下系统地研究了这五种萃取剂的萃取能力和萃取机理。发现在最佳条件下，可以用由三正辛胺或甲基三辛基氯化铵组成的有机相萃取98％以上的钼。结果表明，三正辛胺和甲基三辛基氯化铵具有优异的钼萃取能力，其余萃取剂的萃取能力依次为磷酸二（2-乙基己基）胺>三（2-乙基己基）胺>三丁基。磷酸盐。在汽提过程中，NH 结果表明，三正辛胺和甲基三辛基氯化铵具有优异的钼萃取能力，其余萃取剂的萃取能力依次为磷酸二（2-乙基己基）胺>三（2-乙基己基）胺>三丁基。磷酸盐。在汽提过程中，NH 结果表明，三正辛胺和甲基三辛基氯化铵具有优异的钼萃取能力，其余萃取剂的萃取能力依次为磷酸二（2-乙基己基）胺>三（2-乙基己基）胺>三丁基。磷酸盐。在汽提过程中，NH_选择4 OH，NaOH和H ₂ SO ₄作为汽提剂，从负载的三正辛胺有机相中汽提钼。三种研究的汽提剂的汽提能力依次为NaOH> NH ₄ OH> H ₂ SO ₄。傅立叶变换红外光谱（FTIR）表明，三正辛胺有机相的结构在萃取和汽提过程中是稳定的。结果表明，通过优化的萃取和汽提工艺可以高效率地回收钼。

启示：已经对一系列不同的萃取剂和剥离剂进行了系统的研究，以比较它们在同一系统下的萃取和剥离能力。基于获得的结果，提出了一种优化的萃取和汽提工艺，以有效地从废催化剂中回收钼。通过这种发达的金属回收方法，可以经济和环保的方式处理废催化剂。