钾长石活化焙烧-酸浸新工艺的研究

对湘西某钾长石矿进行了活化焙烧-酸浸新工艺的研究。在焙烧过程中,通过添加低熔点的碳酸钾作助熔剂,使钾长石的熔解在助熔剂的液体状态下进行,在增加反应的接触面积的同时生成了一种在酸性介质下易溶的化合物,从而有效的提高了钾长石的分解能力。在浸出过程中,采用了先水浸后酸浸的方式。由于焙炒本身呈碱性,先水浸有利于降低其pH值,使得后续的酸浸可在保持酸度不变的情况下提高钾长石的分解率。本试验主要考察了焙烧过程中助熔剂与矿石的物料配比、焙烧温度、焙烧时间以及硫酸浸出过程中酸浸液固比、硫酸浓度、酸浸温度、酸浸时间等因素对钾长石分解率的影响。试验结果表明:焙烧过程中控制助熔剂碳酸钾与钾长石的质量比为0.7,在950℃下焙烧1.5h后所得的物料,用3mol/L硫酸在室温下浸出1h,控制液固比为3∶1,钾长石的分解率可达96%。

Research on the New Technology of Activated Roasting-Acid Leaching of Potash Feldspar

The new technology of activated roasting-acid leaching of potash feldspar in Xiangxi was researched in this paper.During the roasting process,by adding the low melting point potassium carbonate as flux,the potassium feldspar can be dissolved in the liquid state of the flux,which can increase the contact area and generate a compound soluble in the acid medium.This made the degrading ability of potassium feldspar effectively improved.During the leaching process,the way that water leaching was followed by acid leaching was adopted.Because the roasting itself is alkaline,the first water leaching could reduce the pH value,which can make subsequent leaching improve the degrading rate of potassium feldspar without the change of acidity.In this experiment,during the coasting course,such factors which influenced the degrading rate as the material ration of flux and ore,roasting temperature and roasting time were investigated.During the course of leach course,such factors as the ration of liquid to solid,the concentration of sulfuric acid,leaching temperature and leaching time were investigated.The results showed when the mass ration of flux and otash feldspar was 0.7,the potash feldspar ore was roasted at 950℃ about 1.5h,the achieved material was leached by 3mol/L about 1h at room temperature and the ration of liquid to solid was 3∶1,the degrading rate of potash feldspar could reach 96%.