有机酸溶浸深部杂卤石工艺及机理

采用草酸、甲酸对四川块状杂卤石进行溶浸试验,研究杂卤石矿在有机酸中的溶出机理,指导深部杂卤石的溶采开发。考察了溶浸时间对K+、Mg2+、Ca2+浓度与溶出率的影响,并对比了溶浸前后杂卤石的物相及形貌变化。结果表明:有机酸溶浸剂有利于K+、Mg2+溶出,不利于Ca2+溶出;有机酸溶浸液经加热浓缩后用无水乙醇洗涤,得到的产物主要为钾、镁硫酸盐,产物成分简单,有利于后期硫酸钾产品的提纯。有机酸溶浸杂卤石矿主要通过酸解反应分解菱镁矿,生成的CO2对矿石有崩解作用,二者作用促进内部杂卤石的暴露与溶解。

Process and Mechanism of Leaching Deep-seated Polyhalite with Organic Acid

The leaching experiment of blocky polyhalite from Sichuan was conducted by using oxal-ic acid and formic acid .This paper mainly study the mechanism of dissolution of polyhalite in or-ganic acid, and to guide the industrialization of mining deep -seated polyhalite .The influence of dissolution time on the concentration and recovery of K +, Mg2+, Ca2+as well as the phase and morphology of polyhalite were investigated .The results indicated that organic acids were in favor of dissolution of K +, Mg2+, but adverse to dissolution of Ca 2+.Organic acid leaching solution was firstly concentrated by heating and then washed by ethanol .The product mainly included potassi-um, magnesium sulfate , which was simple and conducive to the purification of potassium sulfate . The dissolution occurred mainly through acid hydrolysis reaction of magnesite and the disintegration effect of CO 2 on the internal structure of polyhalite , both of which could promote internal exposure and dissolution of polyhalite .