Purification method of high-purity quartz sand

The invention relates to a purification method of high-purity quartz sand, and belongs to the technical field of purification of high-purity quartz sand. The method comprises the following steps: by taking an acidic oxide B2O3 or SnO2 as a fluxing slag agent, determining the addition amount of the fluxing slag agent according to a B2O3-SiO2 or SnO-SiO2 binary phase diagram; quartz sand is crushed and ball-milled into quartz sand powder, and the quartz sand powder and the fluxing slag agent are uniformly mixed to obtain a mixture; under the inert gas atmosphere, the mixture is placed in a high-temperature furnace to be heated and melted, and heat preservation smelting is conducted to form a co-melt; and under the inert gas atmosphere, slowly cooling the co-melt to the eutectic point temperature of B2O3-SiO2 or SnO-SiO2 at a constant speed, carrying out heat preservation until the melt is completely solidified so that SiO2 is separated out and is separated from a slag phase, then cooling to the room temperature