Kinetics of Leaching RE from Panxi Mn-containing Mud with Hydrochloric Acid
攀西高锰稀土矿泥盐酸浸取稀土动力学

The kinetics of leaching RE from Panxi Mn-containing mud with hydrochloric acid was investigated. The effects of reaction temperature, particle size and HCl concentration on the leaching rate were determined. The apparent activation energy is 9.59 kJ/mol as calculated from the experimental data. The results show that the leaching process can be described by the shrinking core model as HCl concentration is below 2.0 mol/L and the leaching rate is controlled by diffusion of reacting reagents and leached products in the porous solid layer. An empirical rate constant of the leaching kinetics is determined to be: when r0 the ore radius is measured in the unit of mm. When HCl concentration is above 2.0 mol/L, the leaching mechanism changes from inner diffusion control to mixed control mechanism because the original ore structure is destroyed.