Abstract: A process for extracting gold from a gold-bearing ore. The process includes, first, providing a leaching liquor with thiosulfate anion and ethylenediamine. Next, the leaching liquor is contacted with the gold-bearing ore to form a pregnant leach solution including gold dissolved from the gold-bearing ore. Finally, at least part of the gold in the pregnant leach solution is recovered.

Abstract: A method for recovering precious metals such as gold and silver from aqueous solution as solid is described The method includes mixing an aqueous solution (e.g, thiosulfate or thiocyanate lixiviant) containing precious metals with ferrous ions in the presence of an effective amount of hydroxide ions. The precious metal ions are reduced and co-precipitate with iron hydroxides and/or hydrated iron oxides The co-precipitate is collected and purified. De-oxygenation of the reaction solution is optional. The recover/method is fast, complete and clean.