汽车尾气催化剂中铂族金属回收工艺概述

Review on recycling PGMs in automobile exhaust-gas catalysts

我国铂族金属资源稀缺,从二次资源中回收铂族金属,对于实现可持续发展和环境保护都具有重要意义。综述了目前从报废汽车尾气净化催化剂中回收铂族金属的研究进展,包括预处理、富集和精炼与分离过程。预处理作用是打开废催化剂的包裹或增大与溶液的接触面积。富集是最回收废催化剂最为关键的步骤,湿法富集过程繁琐,周期较长、废水量较多,回收率不稳定。火法富集,以铁、铅、铜、锍的金属熔炼捕集为主,铅、锍熔炼过程会产生毒性物质,铜价格昂贵,而铁捕集具有经济廉价、且工艺流程短、无污染等特点,是未来处理汽车尾气催化剂的发展方向之一。精练与分离步骤包括沉淀、萃取、离子交换以及电解,其中电解法是未来的方向。

Platinum group metals(PGMs)resources are scarce in China, sorecovering PGMs from secondary resources is of great significance for sustainable development and environmental protection.The research progress of PGMs recovery inautomobile exhaust-gas catalystswas reviewed.The recovery processes includepretreatment, enrichment, refining and separation.Pretreatment is to open the wrapping of waste catalystsand increase the interface contact with solution. Enrichment is the most critical step for recovering waste catalysts. The wet enrichment process is cumbersome andhas disavatanges oflong cycle, generating large amount of wastewater andunstable recovery rate. Pyrometallurgical enrichment mainly focuses on the metal smelting and trapping of iron, lead, copper and matte. The smelting process of lead and matte produces toxic substances, whilethe cost of copper enrichment is expensive. However, iron trapping has the benefits of economy, low cost, short process flow and no pollution. It is one of the development directions for treating automobile exhaust catalysts in the future. The refining and separation steps include precipitation, extraction,ion exchange and electrolysis which is the future direction.