Pressure Leaching Kinetics of Microwave-activated Copper Sulfide Concentrate

The pressure leaching kinetics of microwave-activated copper sulfide concentrate is studied and further compared with that of the pretreated concentrate in the following conditions:the leaching temperature is from 408 K to 453 K; the initial sulfuric acid concentration is 1.23 mol/L; the ratio of liquid to solid as 30/1(mL/g); the oxygen partial pressure is 0.6 MPa; the agitation speed is 500 r/min.The results show that the leaching behaviors of both copper and zinc are similar to those of the pretreated concentrate.The leaching rate of copper is also approximate to that of the pretreated concentrate in the range of leaching temperature from 408 K to 438 K.When the leaching temperature is heated to 453 K, the leaching rate of copper is slightly higher than that of the pretreated concentrate. When the leaching temperature is lower than 423 K, the leaching rate of zinc is slightly higher than that of the pretreated concentrate.However, the leaching of zinc is slowed while the leaching temperature is higher than 438 K. The apparent activation energy is determined as 56.33 kJ/mol and 49.77 kJ/mol for the leaching of copper and zinc respectively.The leaching of both copper and zinc for microwave-activated concentrate follows the shrinking core model with surface reaction control.The leaching of both copper and zinc is promoted after the copper concentrate is pretreated by microwave activation.