铜捕集法回收铂族金属的理论及实验研究

Theory and practice on recovery of platinum group metals from spent auto catalysts by reduction-smelting copper trapping method

对还原熔炼铜捕集法从失效汽车催化剂中回收铂族金属的基础理论进行研究并进行实验验证。计算整个过程可能发生的反应ΔGTΘ-T方程式。分析表明,铂族金属氧化物优先于氧化铜被还原为金属态,实际还原熔炼温度应低于1500℃;计算含MgO的CaO-Al2O3-SiO2熔炼渣体系相图及黏度,熔炼过程应控制CaO、SiO2的量来实现渣型的选择;结合从铜-铂族金属相图,铜能与铂、钯、铑连续固溶形成合金;从理论上证实铜捕集法从失效汽车催化剂中回收铂族金属的可行性;通过实验验证,结果表明在适宜的条件下,铂、钯、铑回收率分别为98.2%、99.2%、97.6%。

The basic theory on recovery of platinum group metals from spent auto catalyst by reduction smelting copper trapping method was studied and the experimental verification was carried out.The △GTΘ-T equations of possible reactions in the whole process were obtained through theoretical calculation,and the analysis shows that the platinum group metals oxides are reduced to metallic state in preference to copper oxide,and the actual reduction smelting temperature should be lower than 1500℃.The phase diagram and viscosity of CaO-Al2 O3-SiO2 smelting slag containing MgO system were calculated,and the amount of CaO and SiO2 should be controlled in the smelting process to implement choice of slag type.It can be seen from the copper-platinum group metals phase diagrams that copper can form the continuous solid solution with platinum palladium and rhodium.The feasibility of recovering platinum group metals from spent auto catalyst by copper trapping method is proved theoretically.The recoveries of platinum,palladium and rhodium are 98.2%,99.2% and 97.6%,respectively,under the appropriate conditions by practical experimental verification.