铬渣NaCl浸出动力学

Kinetics of chromium-containing slag leached by NaCl

通过研究铬渣NaCl浸出过程中Cr(Ⅵ)浓度随时间的变化,建立该反应的动力学方程,确定初始pH值、振荡速度对反应速率常数的影响,并计算相应的反应表观活化能。结果表明,铬渣NaCl浸出过程为0.26级反应,反应速率常数为3.38×10-7 mol/(L.s);pH值和振荡速度增大,反应速率常数不断增大,CaCrO4溶解率增加,溶解速率加快;该反应的表观活化能为34.24 kJ/mol,Cr(Ⅵ)浸出速率受温度影响较大。

The effects of initial pH value and shaking speed on reaction rate constant were confirmed with the change of Cr（Ⅵ） concentrations in leaching chromium-containing slag process by NaCl. Kinetic equation was established and the corresponding apparent activation energy was calculated. The results indicate that the leaching process is a 0.26 order reaction, and the reaction rate constant is 3.38 × 10^-7 mol/（L·s）, The reaction rate constant increases with the increase of pH value and shaking speed, And dissolution rate of CaCrO4 increases too. The apparent activation energy is 34.24 kJ/mol and temperature has great influence on Cr（Ⅵ） leaching rate.