| 摘要 |
<p>A cyanide-free bath for the electrodeposition of gold includes a conductive salt such as the ammonium or alkali metal salt of an inorganic or weak organic acid, e.g., sulphuric, sulphurous, carbonic, boric, sulphamic, acetic or citric acid; and gold in the form of a thiosulphato-complex in a concentration of 3 to 30 g/litre, the complex being sodium dithiosulphatoaurate (I) or sodium heptathiosulphato-aurate (I). The bath may also contain, as a reducing agent, an alkali metal nitrite or sulphite, and, as a buffer or pH regulator, sodium borate, potassium metabisulphite or a mixture of boric acid and ethylene glycol.</p> |
