Method for back extraction of platinum in tributyl phosphate

摘要

PURPOSE: To completely strip platinum with water by mixing a platinum ioncontaining tributyl phosphate with water and adding a reducing agent and an alkali thereto specify the pH and oxidation-reduction potential of the mixed solution. CONSTITUTION: Platinum dissolved in an acid in a non-ferrous metal refining process or a treating process of a platinum catalyst or the like is stripped with tributyl phosphate. The platinum ion-containing tributyl phosphate is mixed with water, and the reducing agent (sulfur dioxide or the like) and the alkali (sodium bicarbonate) are added thereto to adjust the pH and the oxidation- reduction potential of the solution respectively to -0.5 to +7 and -300 to +500mV (to Ag/AgCl electrode). As a result, platinum ion contained in tributyl phosphate is completely stripped.