Preparation method of raw material sand for quartz crucible

Abstract

The invention discloses a preparation method of raw material sand for a quartz crucible. The method comprises the following steps: adopting cocoamine acetate, sodium petroleum sulfonate and pine oil to perform targeted mica flotation, iron flotation and feldspar flotation against feldspar, mica, iron oxides and the like in quartz sand so as to remove the mica, the feldspar, and iron impurities in ore, then performing acid treatment by applying hydrofluoric acid to further remove the mica, the feldspar and the iron impurities in the ore, and finally using a 20000 Gauss magnetic field to perform separation so as to remove iron and other magnetic foreign and miscellaneous matters; introducing oxygen and nitrogen for calcination under high-temperature conditions, performing high-temperature purification with hydrogen chloride gas and performing further refining to improve the purity of the quartz sand and further improve the viscosity of the quartz crucible. The raw material sand for the quartz crucible, prepared according to the invention, can be comparable to high-purity quartz sand of U.S. UNIMIN Company in the aspects of purity and viscosity, the price is just 1 / 2 of the high-purity quartz sand, and the localization of the high-purity quartz sand is further realized.

Description

Technical field [0001] The invention relates to a process for preparing high-purity quartz sand, in particular to a method for preparing raw material sand for quartz crucibles. Background technique [0002] Quartz crucible is a consumable vessel for drawing single crystal silicon. One quartz crucible is used every time a furnace of single crystal silicon is produced. Because single crystal silicon is the main raw material for the production of large-scale integrated circuits and solar cells, the use of quartz crucibles The requirements are very demanding. The geometric size and appearance of the quartz crucible are determined by the production process, and the purity is determined by the raw materials. The raw materials used in quartz crucibles require high purity, good consistency, and uniform particle size distribution. High harmful components will affect the melting of the crucible and affect its temperature resistance. There will also be bubbles, stains, peeling, etc., which...

AI Technical Summary

Problems solved by technology

The raw materials used in quartz crucibles require high purity, good consistency, and uniform particle size distribution. When the harmful components are high, it will affect the melting of the crucible and affect its temperature resistance. There will also be phenomena such as bubbles, stains, and peeling, which seriously affect the quartz crucible. the quality of

[0003] The production of high-quality quartz crucible requires not only advanced technology, but also high purity of raw materials. At present, the quartz sand produced by continuous flotation, mixed acid treatment, water quenching, magnetic separation and other processes in China has the appearance of quartz crucible due to poor purity. Bubbles, black spots, white spots and other undesirable phenomena, as well as low viscosity of the crucible lead to short service life of the crucible

At present, the domestic high-purity quartz sand cannot meet the requirements of high-purity and high-quality quartz crucibles; in order to produce high-quality products, the raw materials for the production of high-purity quartz crucibles in my country are basically all imported from the United States UNIMIN (Unimin) company. Pure quartz sand, although its raw material quality is good, but the price is very high