钾长石矿热分解过程的研究

Studies on the Thermal Dissociative Process of Microcline

研究了钾长石矿热分解过程的反应行为和动力学．对６种钾长石体系进行了热力学分析，计算了各反应在８００～１６００Ｋ的ΔＧ０Ｔ，并以此指导实验．研究了焙烧温度、停留时间和助剂配比对钾长石体系热分解为水溶性钾的影响，得出最佳操作条件．添加０．９％添加剂Ｉ能使适宜焙烧温度由１３２３Ｋ降至１２２３Ｋ，钾分解率可达８４％．不加与加入添加剂Ｉ的２种钾长石体系热分解过程皆符合克－金－布动力学方程，均受固膜扩散控制，表观活化能分别为１８４．８４ｋＪ／ｍｏｌ和１５８．９ｋＪ／ｍｏｌ，并给出相应的动力学方程．

The microcline CaSO 4 CaO system was determined to be used to obtain K 2SO 4 by thermodynamical analysing and computing lots of possible reactions of 6 microcline systems. The effects of roasting temperature, time and ratios of reactants on the potassium recovery of the microcline CaSO 4 CaCO 3 were studied and the favorable conditions were determined as follow: 1 323 K, 3.0 h, m (microcline)∶ m (CaSO 4\52H 2O)∶ m (CaCO 3)=1∶1∶3. In the presence of 0.9% additive I, the roasting temperature decreased from 1 323 K to 1 223 K and the potassium recovery was 84%. Kinetic experimental data of the two systems with or without additive I both fitted a diffusion through product layer reaction control model, and their kinetic equations were presented with apparent activation energies 184.4 kJ\5mol -1 and 158.9 kJ\5mol -1 respectively.