The preparation method of β-citrate gold potassium composite gold salt for gold plating

Abstract

The invention discloses a preparation method of β-gold-potassium citrate composite gold salt for gold plating. The molecular formula of the β-gold-potassium citrate composite gold salt is KAu(CN)2 nK3C6H4O6OHCNH, n=(5.0× 10‑3)~(5.15×10‑3). The preparation method of the present invention is to detect and control the concentration of cyanide ions in the electrolyte during the process of complexing and forming potassium gold cyanide ion by electrolytic reaction, and stop the electrolysis when the concentration of cyanide ions is between 0.003% and 0.03% by weight. Then add a calculated amount of potassium citrate to the electrolyte to form a composite gold salt. The preparation method of the invention is simple and easy, is beneficial to large-scale production, and has the advantages of low product toxicity, high gold content, and the like.

Description

technical field [0001] The present invention relates to a kind of preparation method of β-gold potassium citrate complex gold salt for gold plating, especially the β-gold potassium citrate eutectic compound suitable for chemical gold plating, and further relates to its preparation method, the method can Reduce the use of potassium cyanide. Background technique [0002] There are mainly two commercial gold complexes in the electroplating industry, namely cyanide and sulfite. Since the instability constant of cyanide is much smaller than that of sulfite, cyanide is widely used in the electroplating industry. Salt system is used as the main salt for gold electroplating, especially potassium aurous cyanide is currently the most widely used. [0003] According to investigations, the annual consumption of potassium aurous cyanide in China is about 300 tons. The traditional preparation methods of potassium aurous cyanide are mostly chemical methods or electrolytic methods, and the...

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Problems solved by technology

[0005] According to the reaction formula, it is known that about 0.4513 kg of potassium cyanide (molecular weight: 65) is needed to produce 1 kg of potassium aurous cyanide (molecular weight: 288) in theory, but the actual amount used by producers is as high as 1.2 to 1.8 kg, and the actual amount is higher than the theoretical amount. A full 0.7487-1.3487 kg is added, so a considerable amount of potassium cyanide will be wasted for every 1 kg of potassium aurous cyanide produced. In conversion, at least 224.6-404.6 tons of potassium cyanide will be wasted every year, consuming environmental treatment costs

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