A process as claimed in claim 1, 3 or 4, wherein the acidic solution is a thiourea or thiocyanate solution and has a pH in a range of 1.5 to 3.0.ġ1. A process as claimed in claim 1, 3 or 4, wherein the acidic solution contains gold in a concentration range of 2 mg/L to about 2 g/L.ġ0. A process as claimed in claim 1, 3 or 4, wherein the treatment of the acidic solution with stabilized alkali metal borohydride is effected at ambient temperature and pressure.ĩ. A process as claimed in claim 1, 3 or 4, wherein the acidic solution is obtained in the final recovery step of either the extraction of cyanide leach liquor by an organic solvent followed by stripping of the organic phase by acidified thiourea or the treatment of cyanide leach with ion-exchange resin followed by elution of the resin by acidified thiourea or thiocyanate.Ĩ. A process as claimed in claim 1, 3 or 4, wherein the acidic solution is obtained as a result of the acidification of gold cyanide leach liquor by acidified thiourea which incorporates a cyanide gas recovery means.ħ. A process as claimed in claim 1, 3 or 4, wherein the acidic solution is a leach solution obtained in the final recovery step of the acidified thiourea leaching of gold ore or concentrate in the presence of carbon followed by elution of the carbon by thiosulfate or thiocyanate.Ħ. Recycling the barren solution to the upstream process, wherein the stabilized solution contains about 12% by weight of sodium borohydride and about 40% by weight of sodium hydroxide.ĥ. A process for recovering high purity metallic gold from an acidic solution of thiourea, thiosulphate, thiocyanate or thiourea leach liquor containing gold values, which comprises: Recycling the barren solution to the upstream process, wherein the stabilized alkali metal borohydride is sodium borohydride in the form of a stabilized aqueous sodium borohydride/sodium hydroxside solution.Ĥ. Separating by filtration the resultant metallic precipitate and, optionally, Treating the solution with stabilized alkali metal borohydride in an amount at least stoichiometrically equal to the amount of gold present in the solution A process as claimed in claim 1, wherein the stabilized alkali metal borohydride is stabilized potassium borohydride.ģ. Treating the solution with stabilized alkali metal borohydride in an amount at least stoichiometrically equal to the amount of gold present in solution separating by filtration the resultant metallic precipitate and, optionally, recycling the barren solution to the upstream process.Ģ. A process for recovering high purity metallic gold from an acidic solution of thiourea, thiosulfate, thiocyanate or thiourea leach liquor containing gold values, which comprises:

Precipitate gold powder