Preparation
Industrially, rhodium can be produced from ores using a dry process; alternatively, it can be obtained from byproducts generated during the extraction of copper and nickel from sulfide ores using a hydrometallurgical process. In the hydrometallurgical process, the residual components after nickel and copper extraction are used as raw materials, extracted with aqua regia, filtered, and the filtrate is used to extract platinum and palladium. The residue is treated with nitric acid, filtered, and then ammonium nitrate is added to the filtrate to react and form ammonium rhodium nitrate precipitate. After refining and filtration, the ammonium rhodium nitrate is reduced with hydrogen to obtain approximately 99.99% pure rhodium.
