Method for extracting platinum and rhodium in platinum and rhodium mixed liquid

The invention relates to a method for extracting platinum and rhodium in platinum and rhodium mixed liquid. The method comprises the following steps of: extracting the platinum the mixed liquid by taking n-octane as a diluting agent and N-butyl valnoctamide as an extracting agent prepared from solutes and adopting a first-stage extraction method; removing impurities from the rhodium and the impurities contained in raffinate through a cation exchange column to obtain a rhodium solution. According to the method, the platinum is extracted and separated by adopting the first-stage extraction method, and the extraction ratio E of the platinum is more than or equal to 99.5%; the rhodium is extracted by adopting a cation exchange column method. The method disclosed by the invention can be used for efficiently separating the platinum contained in the platinum and rhodium mixed liquid and ensures the extraction purity of the platinum and the rhodium.