Abstract
The article is devoted to one of the urgent tasks for the gold mining industry. The dissolution of gold in cyanide solutions proceeds by an electrochemical mechanism, in which the ionization of gold atoms and the reduction of oxygen to hydrogen peroxide occurs not in one act, but as a result of two conjugate reactions. Anodic gold oxidation reaction and cathodic oxygen reduction reaction. In this regard, electrochemical studies are used to study the processes of gold dissolution by removing potentiodynamic polarization curves using modern potentiostats that allow to remove cyclic polarization curves at different polarization rates. In the literature there is information about electrochemical studies of gold dissolution in a mixture of sulfuric and hydrochloric acids, where it is shown that during anodic polarization of gold there is a zone of active dissolution of gold and a region of formation of a passive state, which leads to a decrease in the current strength, and hence the dissolution of gold when the passivation potential is reached, then complete passivation and passivation. Currently, this information is not available for the dissolution of gold in cyanide solutions at different oxygen concentrations. The conducted studies made it possible for the first time to determine the dependences of current changes and passivation potential on the concentration of cyanide and oxygen and to construct triple diagrams of current changes on the concentration of cyanide and oxygen and potential on the concentration of cyanide and oxygen. The obtained dependences make it possible to optimize the process of gold dissolution at gold recovery factories.
Keywords:
gold, cyanidation, electrochemical studies, potentiostat, passivation, current, potential.