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: The present invention relates to a method for the production of palladium(0) powder in which a palladium(0) starting powder is subjected to a thermal treatment in a furnace at a temperature of no more than 370° C. in a hydrogen gas atmosphere.

Abstract: A process for digestion of fine iridium includes (a) alkaline oxidative digestion of 1 part by weight fine iridium and 3 to 20 parts by weight of a combination comprising 40 to 70 parts by weight sodium hydroxide, 15 to 30 parts by weight sodium nitrate, and 10 to 40 parts by weight sodium peroxide in the melt, whereby the sum of the weight fractions equals 100 parts by weight; (b) cooling the digestion material formed in step (a) to 20 to 70° C.; (c) dissolving the acid-soluble fractions of the cooled digestion material in water/halogen hydracid until an acidic aqueous solution with a pH value of ?1 to +1 is obtained; and (d) boiling the acidic aqueous solution obtained in step (c) until the formation of nitrous gases is completed. Insoluble ingredients can be separated from the acidic aqueous solution before or after step (d), if needed.

Abstract: Process for removing precious metal from precious metal-containing catalyst form bodies comprising form bodies and precious metal, whereby the precious metal to be removed is at least one precious metal selected from the group consisting of Au, Ag, Pd, Pt, Ir, Rh, Ru, Os, and Re, comprising the steps of: (a) producing a mixture of precious metal-containing catalyst form bodies in at least one mineral acid that is at least 1N; (b) supplying inert or oxidizing gas into the mixture containing noble metal-containing catalyst form bodies and mineral acid; (c) introducing at least one oxidation agent, in solid or liquid form, into the mixture containing noble metal-containing catalyst form body and mineral acid; and (d) separating the form bodies from the liquid.

Abstract: Method for producing elemental rhodium, comprising the steps of: (1) providing an aqueous suspension of diethylene triammonium hexahalogenorhodate adjusted with hydrohalic acid to a pH value of ?1 to +2; (2) adding a sufficient quantity of reducing agent for complete conversion of the diethylene triammonium hexahalogenorhodate to the suspension provided in step (1) and allowing the reaction to proceed until the formation of elemental rhodium is completed; and (3) separating the elemental rhodium formed in step (2) from the hydrohalic aqueous composition formed in step (2); whereby halogen is bromine and/or chlorine.

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 digestion of fine iridium, comprising the steps of: (a) alkaline oxidative digestion of 1 part by weight fine iridium and 3 to 20 parts by weight of a combination comprising 40 to 70 parts by weight sodium hydroxide, 15 to 30 parts by weight sodium nitrate, and 10 to 40 parts by weight sodium peroxide in the melt, whereby the sum of the weight fractions adds up to 100 parts by weight; (b) cooling the digestion material formed in step (a) to 20 to 70° C.; (c) dissolving the acid-soluble fractions of the cooled digestion material in water/halogen hydracid until an acidic aqueous solution with a pH value in the range of ?1 to +1 is obtained; and (d) boiling the acidic aqueous solution obtained in step (c) until the formation of nitrous gases is completed; whereby a step (e) of separating insoluble ingredients from the acidic aqueous solution can take place before or after step (d), if needed.

Abstract: Method for producing elemental rhodium, comprising the steps of: (1) providing an aqueous suspension of diethylene triammonium hexahalogenorhodate adjusted with hydrohalic acid to a pH value of ?1 to +2; (2) adding a sufficient quantity of reducing agent for complete conversion of the diethylene triammonium hexahalogenorhodate to the suspension provided in step (1) and allowing the reaction to proceed until the formation of elemental rhodium is completed; and (3) separating the elemental rhodium formed in step (2) from the hydrohalic aqueous composition formed in step (2); whereby halogen is bromine and/or chlorine.

Abstract: Process for removing precious metal from precious metal-containing catalyst form bodies comprising form bodies and precious metal, whereby the precious metal to be removed is at least one precious metal selected from the group consisting of Au, Ag, Pd, Pt, Ir, Rh, Ru, Os, and Re, comprising the steps of: (a) producing a mixture of precious metal-containing catalyst form bodies in at least one mineral acid that is at least 1N; (b) supplying inert or oxidising gas into the mixture containing noble metal-containing catalyst form bodies and mineral acid; (c) introducing at least one oxidation agent, in solid or liquid form, into the mixture containing noble metal-containing catalyst form body and mineral acid; and (d) separating the form bodies from the liquid.

Abstract: The present invention relates to a method for the production of palladium(0) powder in which a palladium(0) starting powder is subjected to a thermal treatment in a furnace at a temperature of no more than 370° C. in a hydrogen gas atmosphere.