US Patent 7582136 Recovery of gold from potassium iodide-iodine etching solution

A process for the recovery of gold from a potassium iodide-iodine solution is provided. The gold is precipitated from the solution using a weak acid, (e.g. ascorbic acid), a buffer, (e.g. sodium bicarbonate), and a dye. The precipitate is then removed from the solution resulting in the recovery the gold precipitate and the potassium iodide-iodine solution.