Polycrystalline silicon production process

Abstract

The invention provides a polycrystalline silicon production process capable of simplifying process, reducing energy consumption and saving production cost. A chlorine hydride technique is used to substitute a synthetic process and a cold hydrogenation process in a traditional production system. A condenser and a purifier are used in the invention to substitute a dry recovery system in a traditional production system. A general circulation established between a hydrochlorination process and a reduction process can utilize hydrogen produced in the reduction as a supplementary gas for hydrochlorination, so that the operation cost is reduced. As the hydrochlorination and hydrogen reduction general circulation are realized, only a set of hydrogen compressor needs to be configured after the condenser, so as to save energy; and because of the one-stage compression, the number of one-time configured compressors and standby machines thereof is greatly reduced, thereby reducing one-time investment and operating costs by more than 10%.

Description

technical field [0001] The invention relates to a polysilicon production process, in particular to a polysilicon production system which can simplify the process, reduce energy consumption and save costs. Background technique [0002] At present, more than 80% of polysilicon enterprises at home and abroad adopt the improved Siemens method, but due to the low conversion rate and high energy consumption of silicon tetrachloride in the thermal hydrogenation process, some polysilicon manufacturing enterprises have replaced the traditional one with cold hydrogenation process. The thermal hydrogenation of chlorosilane is used to realize the closed cycle of chlorosilane in the production system, and to achieve the purpose of saving energy and reducing consumption. [0003] Cold hydrogenation was originally a process used to prepare trichlorosilane in the early stage of the silane method, and it was directly introduced into the improved Siemens method. Although compared with the tra...

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Problems solved by technology

[0003] Cold hydrogenation was originally a process used to prepare trichlorosilane in the early stage of the silane method, and it was directly introduced into the improved Siemens method. Although compared with the traditional improved Siemens method, its energy consumption can be greatly reduced, but due to two different systems Integration between, so there is still room for further optimization

[0004] The invention patent with the notification number CN101372336 discloses a polysilicon production method, which recovers, purifies, and condenses the reduction tail gas in the production process, but still uses the dry recovery technology, which needs to be rinsed with liquid silicon tetrachloride In addition to impurities, processes such as absorbents, adsorbents, and adsorption and desorption are also required, so the equipment and process are relatively complicated

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