A kind of preparation method of low-iron ultra-white fused silica ceramic crucible

Abstract

The invention discloses a method for preparing a low-iron ultra-white fused silica ceramic crucible. The high-moisture grinding slurry with a water content of 19-21% and a median particle size of 9-11um is obtained by directly grinding quartz sand with a large diameter to replace the original There is fine powder in quartz sand directly added, which can increase the proportion and dosage of coarse sand in directly added quartz sand, and improve the fluidity of slurry; use small particle size abrasive slurry + large span particle size fused silica sand as the crucible body The basic raw material for forming avoids the main source of iron impurities in silicon ingots, and at the same time improves the whiteness and light transmittance of the crucible; reduces the introduction of iron impurities from multiple links, and indirectly increases the whiteness and light transmittance of the crucible body. On the one hand, it can improve the accuracy of crucible appearance and defect detection, facilitate the promotion of mechanical inspection, and improve production efficiency; efficiency and service life.

Description

technical field [0001] The invention relates to the industry of polycrystalline ingots, in particular to a preparation method for reducing the iron content of a quartz crucible for polycrystalline ingots and improving the light transmittance and whiteness of finished crucibles. Background technique [0002] Traditional polysilicon ingots use fused silica crucible as the main container, and undergo heating, melting, crystal growth, annealing, cooling and other steps under harsh conditions of 1500-1600 °C. The preparation methods of quartz crucible are mainly divided into grouting and coagulation. Both of them need to add fused silica sand to the grinding slurry, or lose water in the plaster mold, or use monomers, initiators, etc. to achieve in-situ solidification. According to the principle of close packing of particles, the existing process ratio adopts the abrasive slurry with small median diameter, the particle size of coarse sand ranges from 10 mesh coarse sand to 40um fi...

AI Technical Summary

Problems solved by technology

[0003] The technical problem to be solved by the present invention is to overcome the grinding slurry with a small median diameter that is often used in the preparation of quartz crucibles in the prior art. The quality of the grinding slurry is not uniform, and it is easy to affect the final quartz due to impurities introduced in the production of the grinding slurry. The quality defect of the crucible provides a way to adjust the existing grinding slurry and directly add quartz sand, improve the process ratio, reduce the introduction of iron impurities from multiple links, and indirectly increase the whiteness and light transmission of the crucible body degree of preparation