低品位钾盐助剂焙烧与水浸及结晶制备钾盐

Preparation of Potassium Salt from Low Grade Potassium Ore with Additive-assisted Roasting, Water Leaching and Crystallization

采用助剂焙烧-水洗浸出-钾盐结晶分离工艺从低品位钾长石中提取钾盐,分析了分解机理与浸出动力学.结果表明,加入复合助剂分解效果较好,在钾长石:氯化钙:碳酸钠=1:0.5:0.1(ω)、800℃焙烧4 h及液固比1 m L/g、80℃水洗2 h的条件下,钾提取率可达91.88%.使用CaCl_2-NaCO_3复合助剂能降低矿石分解温度,水洗浸出阶段主要受内扩散控制.

The technology of extracting potassium salt from low grade potash feldspar was studied by adopting the process of roasting-leaching-separation, and the decomposition mechanism and leaching kinetics were analyzed. The results showed that the decomposition efficiency of ores is better by adding mixed additive agents. The leaching rate of potassium reaches up to 91.88% under the optimum conditions of Ore：CaCl2：Na2CO3=1：0.5：0.1（ω）, roasting 4 h at 800℃, leaching 2 h at 80℃, ratio of liquid to solid of 1 m L/g. The CaCl2-Na2CO3 mixed additive could effectively decrease the decomposed temperature of ore. The stage of leaching potassium was controlled by internal diffusion process.