钾长石焙烧熟料的浸出动力学

Leaching Kinetics of Potash Feldspar Roasted Clinker

以钾长石和Na2CO3焙烧熟料为原料,研究其在Na OH溶液中的浸出动力学.考察了在不同温度和搅拌强度条件下Si O2浸出率与时间的关系.结果表明,Si O2浸出的优化工艺条件为:浸出温度95℃、搅拌强度400 r/min、熟料粒度74?89?m、Na OH溶液浓度0.2 mol/L和浸出时间80 min.在该条件下,Si O2浸出率可达99%.熟料浸出过程受无固体膜生成的化学反应和外扩散混合控制.浸出过程分为两个阶段:0?10 min为反应前期,10?80 min为反应后期,表观活化能分别为15.24和29.94 k J/mol.前期和后期的浸出动力学方程分别为1?(1??)1/3?7.074exp[?15239/(RT)]t和1?(1??)1/3?45.85exp[?29940/(RT)]t.

The leaching kinetics of roasted clinker with Na OH, which was obtained by roasting potash feldspar with Na2CO3, was studied. The effects of temperature and stirring intensity on the leaching rate of Si O2 were examined. The results showed that under the optimal conditions of leaching temperature 95 ℃, stirring intensity 400 r/min, clinker granularity 74-89 -m, Na OH concentration 0.2 mol/L, and leaching time 80 min, the leaching rate of Si O2 reached up to 99%. The leaching process of roasted clinker was mixed controlled by the chemical reaction and external diffusion without the solid product layer. The leaching process included the earlier stage in 0-10 min and the later stage during 10-80 min. The apparent activation energy of two stages was 15.24 and 29.94 k J/mol, respectively. The kinetic equations could be expressed as 1-（1--）1/3-7.074exp[-15239/（RT）]t and 1-（1--）1/3- 45.85exp[-29940/（RT）]t, respectively.