Behavior and Kinetics of Copper During Oxygen Pressure Leaching of Complex Chalcopyrite Without Acid

In this paper, a novel process leaching complex chalcopyrite without acid under oxygen pressure is proposed, and the leaching behavior and kinetic characteristics of copper in the complex chalcopyrite is studied. The results show that in the process of oxygen pressure leaching of complex chalcopyrite the oxidation dissolution of FeS2 occurs first, and then the sulfuric acid required by the reaction is generated, which destroys the embedded structure of various mineral phases in chalcopyrite and makes it dissolve into the leaching solution. The copper in the mineral reacts with sulfuric acid to form copper sulfate which enter into the leaching solution, and the iron in the mineral is mainly transformed to hematite and then remained in the leaching slag. Under the optimal leaching conditions (initial sulfuric acid concentration 0 g/L, reaction temperature 200 ? partial pressure of oxygen 1.2 MPa, mineral particle size - 48 + 38 mu m), the leaching efficiency of copper reached 99.86% after 120 min reaction. The analysis of the kinetic process of oxygen pressure leaching of complex chalcolite based on the "shrinkage core model " showed that the leaching process of chalcopyrite is mainly controlled by chemical reaction. The apparent activation energy of the reaction is 50.646 kJ/mol. In the process of chemical reaction control, the parameters of partial pressure of oxygen and initial radius of mineral particles are 4.040 and - 0.773, respectively. The kinetic equation can be expressed as 1 - (1 - X)(1/3) = 1.123 x 10(4) x P-O2(4.040) r(O)(-0.773) 3(-6092/r)t. [GRAPHICS]