Method for preparing alpha-alumina powder for liquid crystal substrate glass

Abstract

The invention discloses a method for preparing alpha-alumina powder for liquid crystal substrate glass, which is prepared from the following raw materials in part: 90 to 99 parts of first class industrial alumina or / and first class industrial aluminium hydroxide, 0.3 to 5 parts of boric acid, 0.2 to 5 parts of ammonium chloride and 0.2 to 2 parts of barium fluoride. The method comprises the following steps: firstly, mixing the raw materials uniformly, placing the mixture in a tunnel kiln, calcining the mixture at the calcination temperature of 1450 DEG C and keeping the temperature for 6 hours; secondly, sorting and grading the quality of a product of the first step, crushing, grinding and grading the product by placing the product in a continuous ball-grinding grading production line to obtain alumina powder with the required grain size distribution; and thirdly, putting a product of the second step into purified water, washing the product to make a pH value of the alumina powder between 7.5 and 8.5, and drying the product to obtain the alpha-alumina powder. The alpha-alumina powder for the liquid crystal substrate glass prepared by the method has the following specific indexes: Al2O3 content of more than or equal to 99.8 percent, alpha-phase transformation rate of more than or equal to 98 percent, SiO2 content of less than or equal to 0.03 percent, Fe2O3 content of less than or equal to 0.02 percent, Na2O content of less than or equal to 0.02 percent, C content of less than or equal to 0.01 percent, Cl<-> content of less than or equal to 0.001 percent, SO3 content of less than or equal to 0.01 percent, ignition loss of less than or equal to 0.01 percent and alpha-alumina grain size of between 30 and 75 micrometers.

Description

technical field [0001] The invention relates to a preparation method of alpha-alumina powder, in particular to a preparation method of alpha-alumina powder for liquid crystal substrate glass. Background technique [0002] In the 21st century, the electronic information industry has become an important driving force for China's economic giant to break through the waves. The new liquid crystal flat panel display industry is booming, and the demand for liquid crystal glass is increasing day by day. At present, α-alumina powder for liquid crystal substrate glass is mostly imported from abroad, and its price per ton is between 20,000 and 30,000 yuan, which makes the manufacturing cost of liquid crystal substrate glass remain high. Contents of the invention [0003] The purpose of the present invention is to provide a method for preparing α-alumina powder for liquid crystal substrate glass with high purity, reasonable particle size distribution, stable composition and performan...

AI Technical Summary

Problems solved by technology

At present, α-alumina powder for liquid crystal substrate glass is mostly imported from abroad, and its price per ton is between 20,000 and 30,000 yuan, which makes the manufacturing cost of liquid crystal substrate glass remain high.