Image Number 5 for United States Patent #4462879.
A simplified, safe, fast and economical method of refining gold and a versatile apparatus for practicing the method are disclosed. The process and the apparatus are ideally suited for reclaiming substantially pure gold from gold jewelry and gold alloy scrap. Gold alloy to be refined is inquarted with a non-ferrous metal or metal alloy and the resulting gold alloy is cast into slab anodes which are suspended in an electrolytic cell containing a nitric acid solution as the electrolyte. The cell includes a stainless steel container cathode to retain gold mud or slime precipitated from the slab anode during the electrolytic process. If platinum and/or palladium are present in the gold alloy to be refined, inquartation with silver is carried out, and these platinum metals are dissolved in the electrolyte solution. If iridium or any other platinum metals are present in the gold alloy to be refined, they will remain in the resulting gold mud and subsequent treatment with aqua regia is necessary.