Abstract: A method for comminuting spent, catalyst-coated PEM membranes from PEM fuel cells and/or PEM electrolysis cells by means of a cutting mill.

Abstract: A method for recovering precious metal from an acidic aqueous solution containing dissolved precious metal and free chlorine, comprising the following successive steps: (1) combining a salt of a non-precious metal present in a low oxidation state as a solid or as an aqueous solution with the acidic aqueous solution to consume the free chlorine and form an acidic aqueous mixture, and (2) adding non-precious metal to the acidic aqueous mixture formed in step (1) to precipitate elementary precious metal.

Abstract: A method for recovering precious metal from an acidic aqueous solution containing dissolved precious metal and free chlorine, comprising the following successive steps: (1) combining a salt of a non-precious metal present in a low oxidation state as a solid or as an aqueous solution with the acidic aqueous solution to consume the free chlorine and form an acidic aqueous mixture, and (2) adding non-precious metal to the acidic aqueous mixture formed in step (1) to precipitate elementary precious metal.

Abstract: Process for the production of particulate ruthenium with a purity of ?99.99 wt. % and a specific surface area of 0.2-0.5 m2/g, comprising: (1) providing a hydrochloric solution prepared by dissolving RuO4 in hydrochloric acid and has a content of ruthenium in the form of dissolved ruthenium species of 15-22 wt. %; (2) providing an aqueous solution with an ammonium chloride content of 200-600 g/litre; (3) forming a reaction mixture by dosing the hydrochloric solution provided in step (1) to the aqueous solution provided in step (2) at a molar ratio of 1 mol ruthenium: 3-6 mol ammonium chloride, at a temperature of 55-90° C. over the course of 0.2-5 hours and while adjusting and maintaining a pH of ?0.6 to 0; (4) separating solid material formed during step (3) from the hydrochloric reaction mixture; and (5) calcinating the solid material separated in step (4) at an object temperature of 350-1,000° C.

Abstract: Process for the production of particulate ruthenium with a purity of ?99.99 wt. % and a specific surface area of 0.2-0.5 m2/g, comprising: (1) providing a hydrochloric solution prepared by dissolving RuO4 in hydrochloric acid and has a content of ruthenium in the form of dissolved ruthenium species of 15-22 wt. %; (2) providing an aqueous solution with an ammonium chloride content of 200-600 g/litre; (3) forming a reaction mixture by dosing the hydrochloric solution provided in step (1) to the aqueous solution provided in step (2) at a molar ratio of 1 mol ruthenium:3-6 mol ammonium chloride, at a temperature of 55-90° C. over the course of 0.2-5 hours and while adjusting and maintaining a pH of ?0.6 to 0; (4) separating solid material formed during step (3) from the hydrochloric reaction mixture; and (5) calcinating the solid material separated in step (4) at an object temperature of 350-1,000° C.