The Research On Copper-nickel Alloy Oxygen Selective Leaching Process

The technology of copper-nickel alloy oxygen selective leaching has been used in industrial production in JinChuan Company. Because of lacking the understanding on reaction mechanism of process,there are some uncertain factors in production control. It is need to study on the uncertain factors,such as temperature of leaching process, the concentration of hydrogen ions in solution ,the time of leaching and so on. And then, to confirm the conditions in selective separation of copper-nickel process. There will be certain significance in industrial production.This subject studied on thermodynamic factors in copper-nickel alloy oxygen selective leaching process. According to the difference of the physical and chemical properties of Cu²⁺,Ni²⁺,theoretical analysis of dynamics and thermodynamics has been calculated. To make the copper of copper-nickel alloy remains in the slag with Ni leaches into solution in oxygen selective leaching process. The separation of copper from nickel can be achieved. From the aspects of dynamics and thermodynamics, the effect of temperature, the concentration of H⁺, the time of leaching on Cu-Ni separation has been studied. And the operation condition of Cu-Ni separation has been determined.The leaching behavior of Cu and Ni in copper-nickel alloy is studied in hydrochloric acid system ,sulfuric acid system and nitric acid system. The effect of temperature, leaching agent concentration and leaching time on leaching rate of Cu and Ni was investigated. Experimental results show that it is quick for Cu and Ni to be leached in HNO₃ solution, they can not be selectivity separated. In sulfuric acid system ,the leaching percentage is both 65% for Ni and Cu . It is not conducive to separate. In 6.0 mol/L HCl solution at 70℃, the leaching percentage is 90% for Ni and 3% for Cu, so they can be separated.