| 摘要 |
<p>An efficient method is proposed for the recovery of gold value from a waste material containing scrap gold by utilizing a principle that metallic gold can be dissolved at elevated temperatures and specifically precipitated at low temperatures with good reversibility in and out of a specific unique liquid medium which is an organic solvent, e.g., acetonitrile, containing an ionic compound of a first halogen, e.g., quaternary ammonium halides, and an elementary form of a second halogen each in a specified concentration, of which at least either one of the first and second halogens is iodine. Namely, a gold-containing waste material is contacted at a high temperature with the liquid medium to have the gold value dissolved therein and the gold-containing solution is then cooled to a low temperature so that the gold value can be recovered in the form of precipitates in a high purity.</p> |
