Gold-plating electrolyte and process for preparing same

A gold-plating electrolyte which has the following composition, g/l: -hexapotassium-m-ethylenediamine-tetraacetobis- 10.5-210 -(aurous sulphite) -alkali metal salts of ethylenediamine- 17.8-140 -tetraacetic acid -distilled water the balance. - The electrolyte can also incorporate additives-ethylenediaminetetraacetocopper (II)-bis(2-aminoethylammonium) or ethylenediamine tetraacetocadmium-bis-(2-aminoethylammonium) in an amount of from 0.01 to 15 g/l. The process for preparing the gold-plating electrolyte comprises interaction of the reagents-chloroauric acid, salts of alkali metals of ethylenediamineteteraacetic acid, an alkali metal sulphite, caustic potash and ammonium chloride; this process is effected in one stage in distilled water at a temperature of 80 DEG -90 DEG C., the components being present in the following proportions, g/l: -chloroauric acid 12.6-250 -alkali metal salt of ethylenediamine- 39-1,000 -tetraacetic acid -alkali metal sulphite 6-190 -caustic potash 32-800 -ammonium chloride 6.6-132; - As a result of this interaction, a gold-plating electrolyte is obtained along with the precipitate of chlorides and sulphates of alkali metals, which precipitate is separated from the electrolyte by filtration. The electrolyte according to the present invention has a high content of hexapotassium-m-ethylenediaminetetraacetatobis(aurous sulphite) and contains no impurities affecting the progress of the gold-plating process. The process for the preparation of the electrolyte is simple and makes it possible to substantially fully eliminate irrevocable mechanical losses of gold.