Leaching Kinetics of MnO_2 from Electrolytic Manganese Anode Slimes in the Presence of SO_2

摘要

The paper describes the kinetics of MnO_2 from electrolytic manganese (EM) anode slimes leached by SO_2.The effects of stirring speed,SO_2 concentration,temperature, and partical size on the leaching rate of manganese are discussed. Experimental results indicated that the leaching of MnO_2 by SO_2 is 0.86 order with respect to SO_2 concentration. The apparent activation energy values for reaction is 25.7KJ/mol,which is consist with the values of activation energy for diffusion control. The kinetic equation can be expressed as: l-(2/3)x-(1-x)2/3=(k_1/pr){[SO_2]~(0.86)exp(-25700/RT)}t. Meanw -hile, comparative experiments were operated, using analytical class MnO_2 and pyrolusite, the difference among the three MnO_2 simples reaction with SO_2 was identified.