US EPA

4813741 

Journal Article 

Noble Metal Recovering by Electroless Displacement Deposition on Silicon Powder 

Fukuda, K; Yae, S; Fukumuro, N; Sakamoto, S; Matsuda, H 

2013 

Yes 

E C S Transactions
ISSN: 1938-5862 

ELECTROCHEMICAL SOC INC 

PENNINGTON 

ECS Transactions 

53 

19 

69-76 

10.1149/05319.0069ecst 

WOS:000339292700007 

We developed a low-cost, efficient method to recover all noble metals including gold, silver, palladium, rhodium, platinum, osmium, ruthenium, and iridium from aqueous solutions by simply adding hydrofluoric acid (HF) and silicon (Si) powder. The recovery rate depends on the specific surface area of Si, the HF concentration, and the solution temperature. Our method selectively recovers noble metals and copper from a mixture solution of noble and base metal ions, such as nickel, cobalt, and iron, and obtains pure noble metal powder by dissolving Si. The Si powder and the HF solution are expected to be supplied from semiconductor industries, such as the sawdust Si of wafering or dicing and the waste HF solution of wafer cleaning or etching. This new method recovers noble metals from waste (urban mines) using other waste; it also has green electroless deposition. 

Zangari, G; Yoshihara, S; Roy, S; 

978-1-62332-116-1 

Symposia on Green Electrodeposition held at the 223rd Electrochemical-Society (ECS) Meetings 

Toronto, CANADA