Process for treating liquid containing Au-CN compound

摘要

This invention relates to a process for treating a liquid containing an Au-CN compound and optionally an Ag-CN compound to decompose the compound(s) and, at the same time, separate gold and optionally silver from the liquid with ease. When containing the Au-CN compound alone, the liquid is heated at a temperature of at least 170 DEG C. in the presence of at least 0.1 mole of a water-soluble metallic hydroxide per gram atom of the gold in the Au-CN compound. When containing the Au-CN compound and the Ag-CN compound, the liquid is heated at a temperature of at least 170 DEG C. in the presence of a water-soluble metallic hydroxide in a total amount of at least 0.1 mole per gram atom of the gold in the Au-CN compound and at least 0.05 mole per gram atom of the silver in the Ag-CN compound. The compound(s) in the liquid are fully decomposable, and at the same time, gold or both gold and silver can be separated out from the liquid singly as such and recovered with a high recovery rate(s).