Method and device for recovering and purifying argon in monocrystalline silicon production

Abstract

Provided is a method and a device for recovering and purifying argon in monocrystalline silicon production. The method comprises firstly conducting coarse oil removal on argon recovered from a single crystal furnace, compressing, cooling and conducting high-precision oil removal and dedusting; secondly enabling hydrocarbon such as methane and carbon monoxide to be reacted with oxygen to generate water and carbon dioxide through a high temperature catalytic reaction and guaranteeing the oxygen to be excessive in the catalytic reaction; thirdly enabling excessive oxygen to be reacted with added hydrogen to generate the water under effects of a catalytic agent after cooling and enabling argon after two catalytic reactions to penetrate through a normal temperature adsorption unit to absorb the water and the carbon dioxide; cooling the argon, sending a low temperature rectifying tower, enabling the argon, the nitrogen and the hydrogen to produce rectification separation, obtaining pure liquid argon, and conducting repeated heating to obtain pure argon products. The device mainly comprises an oil filter, a catalytic reactor of the hydrocarbon of high temperature catalytic oxidation carbon monoxide and methane and the like, a normal temperature hydrogenation deoxygenization catalytic reactor, a normal temperature adsorption unit for absorbing the carbon dioxide and the water at the normal temperature and the low temperature rectifying tower for rectifying and separating the hydrogen and the nitrogen at the low temperature. The device has the advantages of being high in argon recovery rate, high in purity of recovered argon, low in oxygen content, low in energy consumption for recovery and purification and the like.

Description

technical field [0001] The invention relates to a method and device for recovering and purifying argon in the production of single crystal silicon. Background technique [0002] The Czochralski method (Czochralski method) is the main method for producing monocrystalline silicon, and 70% to 80% of the world's monocrystalline silicon is produced by the Czochralski method. The most commonly used Czochralski process for producing single crystal silicon is a decompression crystal pulling process, which is similar to a vacuum process and a flowing atmosphere process; High-purity argon is introduced into the furnace, and the vacuum pump continuously pumps argon from the furnace to keep the vacuum in the furnace stable at about 20 torr. This process has both the characteristics of vacuum technology and the characteristics of flow atmosphere technology. Vacuum pumps for decompression crystal pulling process generally use slide valve pumps, which are mechanical vacuum pumps that use ...

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Problems solved by technology

The disadvantage of the method in this patent literature is the need to use alkaline solution, the low-temperature rectification adopts a double-tower structure coupling control complex, the normal temperature adsorption regeneration needs to use nitrogen, the low temperature adsorption regeneration needs to use argon, and the recovery rate of argon is low

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