Preparation method of anhydrous boron oxide

Abstract

The invention discloses a method for preparing anhydrous boron oxide. The steps are as follows: (1) boric acid is subjected to vacuum dehydration treatment to obtain boron oxide; (2) boron oxide is placed in a crucible and heated to 400-500°C Keep it for 30 minutes; (3) Dehydrate the boron oxide by microwave heating, the dehydration time is 10-40 minutes; (4) Cool to room temperature under normal temperature and pressure conditions with a water content of less than 1ppm to obtain anhydrous boron oxide. The production process of the invention is simple, the production cost is low, the water content of the obtained product is below 150ppm, and the purity is as high as 99.999%.

Description

technical field [0001] The invention relates to the field of boron oxide, in particular to a preparation method of anhydrous high-purity boron oxide. Background technique [0002] Boron oxide generally exists in the form of colorless glassy crystals or powders. It is the most important oxide of boron. It is widely used as a cosolvent in the decomposition of silicate, a dopant in the preparation of semiconductor materials, and an acid in organic synthesis. Catalysts, refractory additives in the process of paint preparation and preparation of boron elements and various borides, etc. However, as such additives, they have higher requirements on the water content and impurity content of boron oxide, such as in In the crystal preparation process of III-V compound semiconductors such as gallium arsenide, indium phosphide, gallium nitride, etc., anhydrous high-purity boron oxide needs to be used as a liquid sealing agent, and the purity of boron oxide is required to be ≥99.999% and ...

AI Technical Summary

Problems solved by technology

[0003] Usually people use normal pressure method or reduced pressure method to prepare boron oxide, but the water content of boron oxide prepared by this method is relatively high, and there are many impurities, and its water content and impurities are not up to the requirements.

At present, there is also a preparation method of anhydrous boron oxide, such as the Chinese patent whose patent number is 200810155689.X, and the patent name is a preparation method of high-temperature covering agent grade boron oxide. The principle of this invention patent is to first heat boron oxide in the air, Then put the boron oxide into a platinum crucible, place it in a medium-frequency induction heating vacuum furnace at 1500°C, and use a two-stage dehydration process for dehydration to obtain boron oxide with a water content below 200ppm. High temperature requires a lot of energy consumption. Due to the high temperature and high requirements for appliances, platinum crucibles are required to hold boron oxide, so the manufacturing cost is high, which is not conducive to large-scale production of enterprises.