钾长石低温提钾工艺的机理探讨

使用化学试剂与钾长石反应模拟低温提钾过程,通过分析各组分对钾溶出率的影响,初步探讨钾长石低温提钾过程的机理,为该工艺的工业化提供理论依据。钾长石低温提钾过程为:首先是硫酸与磷矿反应产生HF,HF分解破坏钾长石的结构,在此基础上Mg2+,Ca2+与钾长石中的K+发生置换反应成为平衡电荷离子。随着钾长石与模拟磷矿配比的增加,钾溶出率先有所上升,在配比达到0.8∶1时达到最高。随着镁钙比的增加,钾的溶出率出现先增加,在1∶1时达到最高,然后呈现基本水平的趋势。在常见磷矿氟含量范围内,随着氟化钙量的增加,钾的溶出率呈现单调增长。实验表明,组分对钾溶出率影响从大到小为:氟化钙质量>氧化镁与氧化钙质量比>磷酸三钙质量。

Mechanism of low temperature potassium extraction process from potassium feldspar

The low temperature potassium extraction process was simulated by the reaction of potassium feldspar with chemical reagents,the influences of each component on the potassium dissolution rate were analysed,and the mechanism of the low temperature potassium extraction process was preliminarily discussed,which provides a theoretical basis for the industrialization of the process.The mechanism of which is as follows: firstly,hydrofluoric acid is generated by the reaction of sulfuric acid with phosphate rock,then the structure of potassium feldspar is dissolved and destroyed by the produced hydrofluoric acid,and on that basis,the potassium ion in potassium feldspar is displaced by magnesium and calcium ions(becoming the balanced ions).The potassium dissolution rate increases with the increase of the ratio of potassium feldspar and simulated phosphate rock at first,and reaches its highest point when the ratio is 0.8 ∶ 1.The potassium dissolution rate increases with the increase of the ratio of magnesium and calcium at first,and reaches its highest point when the ratio is 1 ∶ 1,and then is on the trend of the basic same level.In the common fluorine content range of the phosphate rock,the potassium dissolution rate monotonely increases with the increase of the mass of calcium fluoride.The experiment shows that the influencing sequence of the components on potassium dissolution rate is: the mass of calcium fluoride > the mass ratio of magnesium oxide and calcium oxide > the mass of tricalcium phosphate.