Method for preparing high-purity quartz sand by using waste quartz crucible, high-temperature furnace, method for preparing high-purity quartz sand and high-purity quartz sand

The invention relates to a method for preparing high-purity quartz sand by using a waste quartz crucible, a high-temperature furnace, a method for preparing high-purity quartz sand and high-purity quartz sand, and the method comprises the following steps: pretreating the waste quartz crucible to obtain pretreated quartz sand; enabling the pretreated quartz sand to be in contact with chlorination gas in a high-temperature furnace, and carrying out chlorination treatment to obtain chlorinated quartz sand; carrying out first heating treatment on the chlorinated quartz sand in the high-temperature furnace in an inert treatment atmosphere, and controlling the pressure in the high-temperature furnace to be first in-furnace pressure; then carrying out second heating treatment, and controlling the pressure in the high-temperature furnace to be second furnace pressure, so as to obtain quartz sand subjected to dehydroxylation and bubble removal treatment; the temperature of the first heating ranges from 700 DEG C to 12