Abstract: 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 359.67 μg/g to 248.87 μg/g, and the purity of high-purity 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 gas-liquid inclusions and high content of Al and Ti impurities in the lattice.