菱镁矿尾矿酸浸动力学研究

Acid Leaching Kinetics of Magnesite Tailings

为了优化菱镁矿尾矿酸浸提镁工艺,提高酸浸效率,对某菱镁矿尾矿中的镁进行了酸浸行为研究,考察了不同反应因素对菱镁矿尾矿中镁浸出率的影响,从动力学角度分析了菱镁矿尾矿中镁的浸出行为。研究结果表明:提高菱镁矿尾矿的细度、硫酸的浓度和浸出温度均有利于镁浸出率的提高,液固比变化对镁浸出率的影响不大。当试样的粒度为0.074~0 mm,硫酸的浓度为1.5 mol/L,浸出液固比为3 m L/g,浸出温度为80℃,浸出时间为2 h时,镁浸出率可达84%。镁的硫酸浸出过程符合液-固相非催化反应的缩芯模型,浸出过程受扩散和化学反应共同控制,浸出反应的表观活化能为21.02 k J/mol。

In order to optimize the process of acid leaching and magnesium extraction,improve the acid leaching efficiency of magnesite tailings,acid leaching behavior of magnesium for magnesite tailings is carried out to investigate the effects of different reaction factors on magnesium leaching rate of magnesite tailings.The leaching behavior of magnesium is analyzed from the perspective of dynamics.The results show that increasing the fineness of magnesite tailings,the concentration of sulfuric acid and the leaching temperature are beneficial to the increase of leaching rate of magnesium,and the variation of liquid solid ratio has little effect on the leaching rate of magnesium.When the particle size of the sample is 0.074 ~ 0 mm,the concentration of sulfuric acid is 1.5 mol/L,the leaching liquid solid ratio is 3 m L/g,the leaching temperature is 80 ℃ for 2 h,the leaching rate of magnesium can reach 84%.The sulfuric acid leaching process of magnesium accords with the shrinking core model of liquid solid non catalytic reaction.The leaching process is controlled jointly by diffusion and chemical reaction,with the apparent activation energy of 21.02 k J/mol.