Using dilute sulfuric acid to directly leach ruthenium distillation residue, the leaching rates of base metals and platinum are low, which leads to difficulty in platinum recovery. After roasting, grinding and reduction pretreatment, the base metals are easily leached. Platinum enriched in the sulfuric acid leaching residue can easily be dissolved in aqua regia, and the dissolution rate is 99%. Ruthenium is also enriched in aqua regia leaching residue. The obtained platinum-containing solution is precipitated by ammonium chloride and then calcined to obtain crude platinum. After the crude platinum is dissolved, it is purified by repeated oxidation hydrolysis and ammonium chloride precipitation refining to obtain a sponge platinum product with a purity of 99.99%, and the platinum recovery rate reaches 98.07%. |