汽车废尾气净化催化剂一次水溶液氯化浸出渣的再浸出  

Re-leaching of leach slag of spent auto-catalyst by aqueous chlorination

作　　者：吴鑫昌 刘源 吴国元 魏晓蓉 束蒙蒙 WU Xin-chang, LIU Yuan, WU Guo-yuan, WEI Xiao-rong, SHU Meng-meng(School of Materials and Engineering, Yunnan University, Kunming 650091, China)

机构地区：[1]云南大学材料科学与工程学院,云南昆明650091

出　　处：《云南大学学报（自然科学版）》2018年第6期1201-1206,共6页Journal of Yunnan University(Natural Sciences Edition)

基　　金：国家自然科学基金(51264039;51764051)

摘　　要：汽车废尾气净化催化剂一次水溶液氯化浸出渣中铂族金属残留高达100~150 g/t,研究渣中残留过高的原因及二次浸出的工艺参数有较强的实际意义.采用正交实验法,开展了浸出渣的二次氯化浸出研究,考察了硫酸浓度、盐酸浓度、氯酸钠用量及温度对Pt、Pd、Rh浸出率的影响.得到了优化的浸出条件,即氯化浸出温度为70℃,硫酸浓度为5 mol/L、盐酸浓度为5.5 mol/L及氯酸钠用量为一次浸出渣量的35%.在此工艺参数条件下对汽车废催化剂进行二次氯化浸出时,铂、钯、铑的浸出率分别达到63.88%、16.92%和15.00%.一次浸出渣的再浸出表明:汽车尾气净化催化剂在催化净化过程及报废后的氯化浸出过程中,有较大比例的贵金属被氧化成难溶的金属氧化物,这是导致一次浸出渣中铂、钯、铑残留过高的重要原因.Platinum group metals in leach slag of spent auto- catalyst by aqueous chlorination residues up to 100-150 g/t,so it is of great practical significance to study the cause of excessive residue in the slag and the process parameters of secondary leaching.The secondary chlorination leaching study of the leaching slag was carried out through orthogonal experiment, and the effects of sulfuric acid concentration, hydrochloric acid concentration, sodium chlorate dosage and temperature on the leaching rate of Pt, Pd and Rh were investigated.The optimized leaching conditions were obtained, that is, the chlorination leaching temperature was 70 ℃, the sulfuric acid concentration was 5 mol/L, the hydrochloric acid concentration was 5.5 mol/L, the amount of sodium chlo- rate was 35% of the amount of leaching slag.Under the conditions of the process parameters,the leaching rates of platinum, palladium and rhodium were 63.88%, 16.92% and 15.00%, respectively.The re-leaching of the prima- ry leach residue indicates：a large proportion of precious metals are oxidized into insoluble metal oxides during catalytic purification process and the process of chlorination leaching of automobile exhaust purification catalyst, which is important reason for the excessive residue of platinum, palladium and rhodium in the primary leaching slag.

关 键 词：汽车废催化剂 水溶液氯化浸出渣 二次浸出 铂族金属 

分 类 号：TF11[冶金工程—冶金物理化学] TF83