Abstract:The method of refining platinum by acid pickling ammonium chloroplatinate to remove impurities was proposed for the first time. The effects of acid pickling reagents, acid concentration, solid-liquid ratio of system, and temperature on impurities removal efficiency by acid pickling were studied. More than 90% of Na, Al, Fe, and Si are removed under the optimum conditions, while the loss rate of Pt is less than 0.3%. The content of impurities except Sn in the sponge platinum prepared by pickling ammonium chloroplatinate reaches the SM-Pt 99.95 standard. The behavior of Sn in the acid pickling process was studied. The results show that either acid pickling or calcination of ammonium chloroplatinate could remove Sn in the form of (NH4)2SnCl6 to achieve the same effect of Sn removal, but could not remove Sn in the form of SnO2.