某矿区高纯石英化学深度提纯技术研究

Research on Chemical Deep Purification Technology of High-purity Quartz in a Mining Area

高纯石英具有耐高温、耐腐蚀、低热膨胀性、高度绝缘性和透光性等优异的物理化学性质,是诸多尖端领域的关键性基础材料。以河南某脉石英经物理提纯后的石英砂精矿为研究对象,开展了化学深度提纯试验研究,并考察了浸出前处理工艺对浸出效果的影响;基于不同用途对高纯石英粒度要求的差异,进一步探讨了石英粒度对化学提纯的影响。研究结果表明,在HF-HCl-HNO3混酸体系中,浸出剂与石英液固比3∶1、浸出时间6 h、浸出温度60℃的条件下,得到了最好的浸出效果,高纯石英中杂质总量从400.67μg/g降低至248.87μg/g,高纯石英纯度达99.975%;试验确定了磨矿分级—色选—重选—磁选—浮选—煅烧—水淬—化学浸出工艺为该脉石英矿的最佳处理工艺;−0.42 mm和−0.25 mm石英砂精矿浸出后,平均粒径分别减少0.09 mm和0.05 mm。高纯石英砂粒度越细,提纯效果越好,化学提纯前后粒度的分析能够有效地为前期磨矿提供指导性意义;由于矿物本身存在缺陷,其中的气液包裹体较多且存在于矿物晶格中的Al、Ti杂质元素含量较高,该矿仅适合用于制备低端高纯石英砂,制备高端高纯石英砂需需寻找低气液包裹体和晶格杂质的高纯石英资源。

High-purity quartz has excellent physicochemical properties such as high temperature resistance,corrosion resistance,low thermal expansion,high insulation and light transmission,and is a key basic material for many cutting-edge fields.The experimental study of chemical depth purification was carried out on quartz sand concentrate after physical purification of a vein quartz in Henan Province,and the effect of leaching pretreatment process on the leaching effect was investigated;based on the difference of particle size requirements of high-purity quartz for different applications,the effect of chemical purification on quartz particle size was further explored.The results showed that under the optimal leaching conditions of HF-HCl-HNO3 mixed acid system,liquid-solid ratio of 3∶1,leaching time of 6h and leaching temperature of 60℃,the impurity content in high-purity quartz was reduced from 359.67μg/g to 248.87μg/g,and the purity of highpurity quartz reached 99.975%;the grinding classification-reconcentration-magnetic separation-flotation-calcination-water quenching-leaching process was determined The finer the particle size of high-purity quartz sand,the better the purification effect,and the analysis of the particle size before and after chemical purification can effectively provide guidance for the pre-grinding;due to the defects of the mineral itself,its gas-liquid inclusions are more and exist in the lattice.The mineral is only suitable for the preparation of low end high purity quartz sand due to the defects of the mineral,which has more gasliquid inclusions and high content of Al and Ti impurities in the lattice.