Selective recovery of platinum and palladium from Asahi's PLS in chloride medium

金、银和包括铂和钯的铂族金属（PGM）被称为“贵金属”，它们非常昂贵，不仅被广泛用作传统的珠宝，而且还被广泛用作包括电子设备在内的各种众所周知的先进材料中的有用组分。朝日炼油加拿大有限公司，朝日控股（Asahi Holdings）的子公司，通过浸出来自采矿和回收行业的二次材料（包括电子废物）来生产贵金属（黄金和银）。浸提后，浸提母液（PLS）在氯化物介质中含有金、银、铂、钯和一些贱金属。目前，Asahi Refining仅通过从该浸提溶液中回收金属金和银来生产金属金和银，从而将所有其他昂贵的PGM留在PLS中，因为他们还没有合适的工艺来在该工艺条件下选择性地回收铂和钯。申请人（Alam博士）拥有使用湿法冶金技术从氯化物介质中回收不同种类贵金属（包括PGM）的丰富经验。在该项目中，将利用从农业、森林和海洋资源的生物质废弃物中提取的具有新型官能团的生物吸附剂，从朝日PLS中选择性地回收剩余的贵金属（铂和钯）。如果拟议的具有成本效益、可持续和环保的工艺获得成功，这将是朝日目前工艺流程中采用的一项创新技术，将产生额外利润，并推动朝日炼油的贵金属回收业务。

Gold, silver and platinum group metals (PGM) including platinum and palladium are named as "Precious Metals", which are very expensive and are widely used not only as traditional jewelries but also as useful components in a variety of well-known advanced materials including electronic devices. Asahi Refining Canada Ltd., a subsidiary of Asahi Holdings, produces precious metals (gold and silver) by leaching secondary materials coming from the mining and recycling industries including electronic wastes (e-wastes). After leaching, the pregnant leach solution (PLS) contains gold, silver, platinum, palladium and some base metals in a chloride medium. Currently, Asahi Refining only produces metallic gold and silver by recovering them from this leach solution leaving behind all other expensive PGM in the PLS, because they do not have a suitable process yet to selectively recover platinum and palladium in that process conditions. The applicant (Dr. Alam), has extensive experiences recovering different kinds of precious metals including PGM from chloride media using hydrometallurgical techniques. In this proposed project, he will selectively recover the remaining precious metals (platinum and palladium) from the Asahi's PLS using bioadsorbents with novel functional groups prepared from biomass wastes derived from agriculture, forest and marine resources. If the proposed cost-effective, sustainable and environmentally friendly process is successful, it would be an innovative technique to adopt in Asahi's current process flowsheet that will generate extra profit and boost the precious metals recycling business of Asahi Refining.