The gold is recovered from the gold - platinum (or gold- palladium ) alloy scrap according to the characteristics that gold and platinum or palladium are insoluble in nitric acid and sulfuric acid, and can be dissolved in aqua regia, and dissolved in aqua regia and separated by ammonium chloride. The platinum is recovered and the gold is recovered from the solution. High Efficiency Slurry Pump,Centrifugal Low Abrasive Slurry Pump,Hydraulic Pump,Lime Grinding Slurry Pump Shijiazhuang Zhongjia Slurry Pump Co.,Ltd. , https://www.zjoemparts.com
Method of operation: The alloy waste is reacted with aqua regia, and concentrated by evaporation to drive off the nitrogen dioxide gas, and the solution is cooled and filtered. The filtrate and the washing solution were combined and mixed, and solid chlorinated to remove colorless. The filter residue is calcined together with the filter paper into an off-white sponge platinum, which is then melted into a metal platinum ingot by a high temperature acetylene flame.
In the filtrate after separation of platinum, gold is in the state of gold trichloride, and gold can be reduced by precipitation with sulfur dioxide gas. The gold powder is washed, dried, and smelted.