With the gold production industry developing, it is most important to develop and utilities the gold ore containing copper, which is an important part of the refractory gold ore in our country. The majority of copper minerals are easily dissolved in cyanide solution. But few research is focused on the dissolving properties of copper minerals in gold ore. Malachite, a representative copper mineral, was used to study the dissolving properties of copper mineral in the cyanide solution in the subject.Based on the reaction thermodynamics of malachite leached in cyanide solution, it is indicated that malachite was almost never dissolved without cyanide at a alkaline environment, while malachite can occur spontaneously dissolves in the cyanide solution. And a higher coordination number in copper cyanide complex is easily to be obtained by increasing the cyanide concentration. Cyanogens could be oxidized by oxygen with pH increasing.The results of the leaching test show that malachite was inevitable to leaching in cyanide solution. Malachite leaching rate increases with a larger concentration of sodium cyanide, a higher temperature and a longer leaching time. The consumption of cyanide cannot decrease by changing oxygen content.The kinetics of malachite leaching in a cyanide solution shows that malachite leaching process can be divided into two stages. The activation energy was 25.472 J·mol-1 at the first stage, the activation energy was 15.522 J·mol-1 at the second stage. The two stages are controlled by the mixed control. The results of the leaching test of gold piece shows that the gold can be dissolved in the copper cyanide complexes with the oxygen. |