PROCESS FOR REGAINING WITH SEPARATION OF PALIADIUM AND RUTHENIUM FROM INACTIVE CATHALIZATORS WITH SOLID MEDIUM

摘要

Recovery comprises dissolving the metals in an oxidising acid medium contg. pref. 15-380 g per litre hydrochloric-and/or sulphuric-acid and 2-25 g per litre hydrogen-peroxide. Metals are sepd. from the soln. in great purity by a two-step process. In the first step palladium is pptd. by electrolysis using a current density of 1-5 mA per square cm. In the second step ruthenium is sepd. either by electrolysis with a current density of 5.5-40 mA per square cm, or by reduction with a less noble metal like pref. zinc, iron or copper. - Electrolysis is carried out with inert electrodes like graphite, platinum or platinised titanium. Process is made more efficient by pref. concentrating the metal soln. before electrolysis by evapn..