process for the electrodeposition of gold for deposits of gold, and electrolyte for the implementation of this process

摘要

939,007. Electro-plating with gold. SELREX CORPORATION. Dec. 15, 1961 [Jan. 24, 1961], No. 45060/61. Class 41. A solution for electro-plating gold contains potassium auricyanide, an alkali metal salt as conductor, and 25 mg. to 500 mg. per litre of silver ion, the solution containing substantially no free cyanide, except that developed in use. Preferably, a chelating agent is added to keep the free silver ion concentration low, e.g. E.D.T.A., pyridine diethyl ethanolamine, triethyltetramine, and eutidine. As conducting salts alkali metal phosphates, nitrates, sulphates, sulphamates, citrate, tartrate, lactate, may be used, or salts of benzene or naphthalene sulphonic acid. The pH value of the solution is maintained at 6.5 to 10. Small amounts of potassium-nickel (or cobalt) cyanide may be present.