Research results of gold-copper concentrate cyanidation with additional introduction of ammonium hydroxide cyanidation in process for combining in a difficult complex of copper, which is harmful impurity at cyanidation are presented. It is shown, that process carrying out at automatic stabilization of cyanide concentration allows to increase gold extraction by 14,7 % in comparison with fractional cyanide delivery and reduces the cyanide expense in 5 times. The action mechanism of ammonium hydroxide is offered.