Method for removing crystallization layer of waste quartz crucible, method for preparing fused quartz powder and fused quartz powder

The invention relates to a method for removing a crystallization layer of a waste quartz crucible, a method for preparing fused quartz powder and the fused quartz powder.The removing method comprises the following steps that at least one time of thermal shock treatment is conducted on the waste quartz crucible, and a waste quartz crucible body and the crystallization layer which are subjected to thermal shock treatment are obtained; the thermal shock treatment comprises the steps of heating the waste quartz crucible to a first temperature and then cooling the waste quartz crucible to a second temperature; the first temperature ranges from 150 DEG C to 1100 DEG C; the second temperature is below 50 DEG C; the average cooling rate is 100 DEG C/min or more; the separation ratio of the devitrification layer is more than 70%. According to the method provided by the invention, the crystallization layer on the inner surface and the outer surface of the waste quartz crucible can be separated from the crucible body, a