标题：Synthetic recovery of spent Co-Mo catalyst by NaOH-leaching
作者：Lu, Guojian ;Ouyang, Chun ;Ran, Weixian ;Zhang, Qianqian ;Xin, Chunyu
作者机构：[Lu, Guojian ] Lianyungang Teachers College, Lianyungang 222006, China;[Ran, Weixian ;Zhang, Qianqian ] College of Chemical and Environmental Engineer 更多
来源：Xiyou Jinshu/Chinese Journal of Rare Metals
摘要：Fractional precipitation method of NaOH-leaching and then H2SO4-acidification were utilized for the recovery of non-ferrous metals, e.g. Mo, Al, Bi, Co, Ni, etc. The spent catalyst was leached with NaOH to transfer molybdenum oxide and aluminum oxide to the soluble salt so as to separate from Bi, Co and Ni oxides. As to the separation of Mo and Al soluble salt, fractional precipitation was introduced to prepare ammonium molybdate and aluminum sulfate. Co, Bi and Ni were effectively separated from the residue by means of fractional precipitation-acid solvent extraction method using their different solubility product properties in hydroxide. Experiments indicated that when the milling time was 30 min, the particles size of the catalyst was less than 74 μm, the additive amount of NaOH was 1.2 times of theory consumption of Mo and Al, the liquid-solid ratio was 4:1 and the leaching temperature was set at 90°C, the first leaching yield of Mo was as high as 96.25%, and it was 99.50% in the secondary leaching process. Bismuth hydroxide precipitate was separated from the residue with the pH value of around 2 by means of heated-acid leaching and oxidation for deironing method. When pH value was controlled at 9.5, Ni and Co was precipitated in the form of hydroxides, and then were separated by the acid-soluble extraction method. After the whole recovery process, the overall recovery of Mo and Al was 94.56% and 96.89%, respectively.