红土镍矿-硫酸铵焙烧熟料铁溶出动力学

Digestion Kinetics of Fe during Leaching from Roasting Materials of Laterite Nickel Ore and Ammonium Sulfate

以红土镍矿-硫酸铵混合焙烧后所得熟料为研究对象,采用水溶出的方法提取铁,系统地研究溶出温度、液固比、溶出时间、搅拌强度对铁溶出率的影响,并对铁的溶出动力学进行探讨。结果表明:在溶出温度60℃、溶出时间60 min、液固比2. 5∶1、搅拌强度400 r·min^(-1)的条件下溶出时,铁的溶出率可达到99%以上;动力学分析表明,铁的溶出反应受外扩散控制,根据阿伦尼乌斯经验方程计算得到反应的表观活化能为E=7. 23 kJ·mol^(-1),得到溶出过程动力学方程为1-(1-α)^(2/3)=0. 208 5 exp(-7 234/RT) t。

The roasting materials of laterite nickel ore and ammonium sulfate were used as the research object for Fe leaching by water dissolution method.The effects of dissolution temperature,liquid-solid ratio,dissolution time and stirring intensity on the dissolution rate of iron were systematically studied.The dissolution kinetics of Fe was also explored.The results show that the dissolution rate of iron can reach more than 99% when the dissolution temperature is 60℃,the dissolution time is 60min,the liquid-solid ratio is 2.5:1,and the stirring strength is 400r·min^-1.The kinetic analysis shows that the dissolution reaction of Fe is controlled by external diffusion.According to the Arrhenius empirical equation,the apparent activation energy of the reaction is E=7.23kJ·mol^-1,and the kinetic equation of dissolution process is1-(1-α)^2/3=0.2085exp(-7234/R T)t.