摘要
采用氢氧化钠碱浸、硫酸酸化分步沉淀法从废催化剂中回收Mo,Al,Bi,Co,Ni等有色金属。首先对废催化剂进行氢氧化钠一、二次碱浸,使氧化钼和氧化铝生成可溶性的盐与氧化铋、氧化钴、氧化镍分离,然后通过分段沉淀使钼和铝分离,制备钼酸铵和硫酸铝。其次对碱浸富集氧化铋、氧化钴和氧化镍渣,利用氢氧化物溶度积不同,采用分步沉淀―酸溶萃取法使钴、铋、镍得到有效分离。试验结果表明:球磨时间30 min、催化剂粒度小于74μm、氢氧化钠的加量为金属Mo和Al理论耗量的1.2倍、液固比选取4∶1、浸出温度90℃时,一次碱浸钼的浸出率可达96.25%,一次碱浸渣再次碱浸率可达99.50%。碱浸富集金属混合渣采用加热酸浸、氧化除铁,将滤液的pH控制在2左右使铋以氢氧化铋沉淀分离,控制pH为9.5,使镍、钴以氢氧化物形式沉淀,然后酸溶、萃取使钴镍分离。整个回收工艺中,钼和铝的总回收率分别为94.56%和96.89%。
Fractional precipitation method of NaOH-leaching and then H2 SO4-acidification were utilized for the recovery of non-fer- rous 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 A1 soluble salt, fractional precipita- tion 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. Experi- ments indicated that when the milling time was 30 min, the particles size of the catalyst was less than 74 txm, the additive amount of NaOH was 1.2 times of theory consumption of Mo and A1, the liquid-solid ratio was 4：1 and the leaching temperature was set at 90 ℃, the first leaching yield of Mo was as high as 96.25%, and it was 99.50% in the secondary leaching process. Bismuth hydroxide precipi- tate 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 A1 was 94.56% and 96.89%, respectively.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2014年第2期270-276,共7页
Chinese Journal of Rare Metals
基金
国家自然科学基金项目(21176145)资助
关键词
钼
铝
氢氧化钠
废催化剂
回收
molybdenum
aluminum
sodium hydroxide
spent catalyst
recovery
