METHOD FOR PREPARING CONCENTRATED RHODIUM ELECTROLYTE Russian patent published in 2022 - IPC C25D3/50 C25D21/18 

FIELD: electroplating.

SUBSTANCE: invention relates to the field of electroplating and can be used for coating the surfaces of parts of sliding contacts operating under harsh conditions while maintaining a stable contact resistance. The method includes obtaining a concentrated solution of rhodium sulfate and sulfuric acid by precipitating rhodium hydroxide from its chloride solution dissolved in water and adding to it a solution of potassium hydroxide heated to a temperature of 60 to 80°C with constant stirring until complete precipitation of rhodium in the form of yellow hydroxide , while the pH of the mother liquor has a value of 7.5-8.0, the resulting precipitate of rhodium hydroxide is washed from chloride ions and dissolved by cooling to a temperature of 12 to 15°С and adding sulfuric acid at a molar ratio of Rh:H₂SO₄=(1:3.5)-(1:4.5), and to increase the dissolution rate of rhodium hydroxide, a 35% hydrogen peroxide solution is added to the reaction mixture in a molar ratio of Rh:H₂O₂=(1:3)-(1:4) to obtain a concentrated solution of rhodium sulfate and sulfuric acid.

EFFECT: obtaining components intended for the preparation, correction and regeneration of the rhodium plating electrolyte used to improve the quality of coatings on the surfaces of parts operating in rotational mechanisms in compliance with electrical parameters.

1 cl