Method for selective extraction of palladium with respect to platinum and rhodium with solutions of dioctyl sulphide in toluene

Abstract

The subject of the application is a method for selective extraction of palladium with respect to platinum and rhodium carried out with solutions of dioctyl sulphide in toluene, which is characterized in that before the first extraction, the organic phase is subjected to preliminary preparation by homogenization for 5 - 10 minutes with a 10% - 15% aqueous ammonia solution in a phase ratio of 1:1, then the organic phase and the aqueous phase are separated and the ammonia solution is removed by known methods, and the remaining organic phase is washed 2 - 5 times with distilled water in the amount of 1 / 5 of the volume of the washed organic phase until the pH of the aqueous phase is <8, after the first extraction of palladium from the resulting extractant in the form of dioctyl sulphide in toluene, re-extraction is carried out using a 25% aqueous ammonia solution at a ratio of the organic phases to the aqueous phase of 1:2, after which the procedure of preparing the organic phase before the next extraction is repeated, i.e.is homogenized for 5 - 10 minutes with a 10% - 15% aqueous ammonia solution, the volumes of both solutions being equal, then the organic phase and the aqueous phase are separated and the ammonia solution is removed by known methods, and the remaining organic phase is washed 2 - 5 times with distilled water in the amount of 1 / 5 of the volume of the washed organic phase until the pH of the aqueous phase is <8.