A preparation method and device for sapphire-grade high-purity alumina block and polycrystalline ingot

Abstract

The invention relates to the technical field of inorganic high-purity powder blocks and polycrystalline ingots, and provides a preparation method for sapphire-grade high-purity alumina blocks and polycrystalline ingots. The preparation method comprises the process steps that hydrolysis synthetization is performed, and high-purity aluminum sheets, catalyst strong base hydroxyl ammonium hydroxide and high-purity water are subjected to hydrolysis reaction to obtain aluminum hydroxide and hydrogen; filtering is performed to obtain completely hydrolyzed aluminum hydroxide; filter-pressing, washing and filter-pressing are sequentially performed to obtain aluminum hydroxide filter cakes and mother liquor; drying is performed; middle-temperature calcination is performed; crushing is performed; and purity testing is performed on a-Al2O3 powder, cold static pressure molding and high-temperature calcination are performed to obtain the sapphire-grade high-purity alumina blocks if the purity reaches the 5N grade, and pelleting and high-temperature melting purification are performed to obtain the sapphire-grade high-purity alumina sintered polycrystalline ingots if the purity does not reach the 5N grade. The invention further provides a preparation device for the sapphire-grade high-purity alumina blocks and polycrystalline ingots. The preparation method and device for the sapphire-grade high-purity alumina blocks and polycrystalline ingots have the advantages of being simple and stable in process, low in cost, and capable of being widely applied to the field of high-purity alumina production.

Description

technical field [0001] The invention relates to the technical field of preparation of inorganic high-purity powder blocks and polycrystalline ingots, in particular to the preparation of high-purity α-Al from high-purity aluminum flakes with a purity >99.99% and above 2 o 3 A green preparation method and industrialized device for powder and polycrystalline block. Background technique [0002] Sapphire is an aluminum oxide (α-Al 2 o 3 ) single crystal has excellent optical properties, mechanical properties and chemical stability. Due to its unique lattice structure, excellent mechanical properties and good thermal properties, it is the most ideal substrate material for LEDs. According to McKinsey's data, the global LED lighting market share will increase from the current 7% to more than 40% in 2016. By 2020, the LED lighting market revenue will be close to 65 billion euros, accounting for nearly 60% of the global lighting market. At present, the scale of China's semicon...

AI Technical Summary

Problems solved by technology

[0007] The purpose of the invention is to overcome the existing high-purity alumina (α-Al 2 o 3 <99.996%) most of the raw materials in the raw material production process are not pure enough, high impurity content, high production cost and secondary pollution, etc., to provide a simple process, no environmental pollution, low cost, and make the main impurity content less than Preparation method and device for limit values ​​allowed for sapphire single crystal growth

Images