High Pressure Chemical Reactor For Granular Polycrystalline Silicon

Shaanxi Nonferrous Tianhong Ruike Silicon Materials Co., Ltd. (hereinafter referred to as "Tianrui Silicon Materials") is a Sino foreign joint venture high-tech enterprise that integrates the manufacturing, sales, service, and research and development of ultra-pure silicon materials. It has the world's leading production technology for electronic grade silane gas, granular polysilicon, and ultra-pure polysilicon. The first phase has completed an annual production of 18000 tons of granular polysilicon, 300 tons of ultra-pure polysilicon The industrialization project of electronic and photovoltaic new materials with a loading capacity of 2000 tons of high-purity silane gas, which produces ultra-pure polycrystalline silicon and high-purity silane gas, fills the domestic gap and significantly improves the supporting level of upstream and downstream industries in Shaanxi Province.

The Tianrui Silicon Materials Phase I project has significant features such as continuous production, closed circuit circulation, clean production, energy conservation and consumption reduction. Since the construction of the project, Tianrui Silicon Materials has always made technology implementation, absorption, and independent research and development a top priority for the company. In August 2020, a number of technicians were organized to go to the United States for process operation training, and the exploration and research and development of new processes and technologies were continuously deepened. On the basis of the first generation silane fluidized bed technology of REC silicon materials, a development model combining imported technology and independent research and development has been adopted to successfully achieve the first comprehensive iteration and upgrading of silane fluidized bed process technology. The FBR-B (second generation silane fluidized bed process) production process technology, which has been developed and put into operation, has a longer actual operating time, higher product quality, and faster purification rate compared to the design value, Its core advantages include reducing the reduction power consumption to 1/10 of the Siemens method, reducing the comprehensive power consumption to 1/3, shortening the purification time of the fluidized bed reactor unit to about 7 days, breaking through the continuous operation time of a single chemical reactor equipment by 800 days, reaching 4 times the design time, and having a single production line feed rate exceeding the design value by 30%. At the same time, it has achieved a 60% equipment localization rate, improving the level of independent and controllable industry. At the same time, Tianrui Silicon Materials is also strengthening independent research and development on core equipment and key spare parts, overcoming the "bottleneck" issues such as domestic ceramic lining, filling the domestic gap, and reducing production and operation costs.

The iterative upgrading of technology has driven a significant leap in the production and quality of granular polycrystalline silicon products. The production capacity has been increased from 10000 tons/year in the first generation technology to 20000 tons/year in the second generation technology, with the quality reaching the photovoltaic special level. Among them, more than 30% of the products have reached the electronic level, and it is the first in the industry to achieve efficient single crystal direct mass application with a product proportion of up to 95%, Establish a remarkable industry strategic position and market influence of Tianhong Ruike brand for granular polysilicon products.

Entering the "14th Five Year Plan" period, Tianrui Silicon Materials closely follows the "dual carbon" goal, seizes development strategic opportunities, and timely plans and organizes the implementation of an 80000 ton electronic grade granular polycrystalline silicon industry upgrade project. It is reported that the project has achieved a comprehensive iterative upgrade of the overall operating system through the second iteration of process technology, forming a 100000 ton production and operation system. The equipment localization rate has reached 80%, the reactor purification time has solidified to less than 7 days, and the product quality has all reached electronic level, with some reaching electronic level 2 to 1. After the new project is put into operation, the reduction in unit consumption and the effect of scale efficiency are evident. Under the condition of a production capacity of 100000 tons, the manufacturing cost has significantly decreased by 33% compared to the current production capacity of 18000 tons/year, reaching a global leading level.

As one of the main products of Tianrui silicon materials, granular polysilicon products have application advantages such as low Carbon footprint, no need of crushing, good fluidity, and strong filling ability, and are ideal for downstream RCZ (Recharged Czochralski multi loading and crystal pulling technology) and CCZ (Continuous Czochalski continuous direct drawing technology) re feeding. With the continuous improvement of the quality and stability of the company's products, the proportion of high-quality plasmid like polycrystalline silicon used in the single crystal field by Tianrui Silicon Materials has increased from 5% in initial testing to 20% in current batch applications, and has passed 30% of the crystal pulling test. With the increase in production and supply, it will bring higher gains to the industrial chain in the future. At the same time, Tianrui Silicon actively expanded the application field of granular polysilicon, reached a cooperative relationship with ACHIEVE CHEM, and took the lead in realizing the diversified application of a full range of granular polysilicon products by silane fluidized bed method.

The preparation of granular polysilicon products usually involves the following chemical machinery equipment:

Reactor: A container used for chemical reaction, which can be a high pressure stainless steel reactor vessel or a jacketed glass reactor.

Heating equipment: Such as electric furnace, heating plate, heating mantle, heating circulator, etc., used to provide the temperature required for the reaction.

Mixing device: Such as digital electric stirrer or magnetic stirring, used to mix and stir reactants.

Filtration equipment: Used to separate solid and liquid phases, such as vacuum filter funnel, filter paper, filter membrane, etc.

Drying equipment: Such as vacuum drying oven, or blast drying oven, etc., used to remove solvent or moisture.

Centrifuge: Used to separate solid from liquid and collect solid products.

The purity of Tianrui silicon material high-purity silane gas products is 99.9999%, and the quality has reached the international advanced level. In addition to being widely recognized in the fields of photovoltaic cells, flat panel displays, and semiconductor manufacturing, breakthroughs have been made in the application of new energy battery materials. The purity of ultra pure zone melting polycrystalline silicon reaches 13N, and the impurity content is as low as ppt (ppt part per trillion) level. It is widely used in new energy vehicles, new energy power generation, industrial automation, rail transit, 5G and other fields.

In recent years, Tianrui Silicon Materials has fully implemented the new development concept, promoted the deep integration of industry chain, talent chain, and innovation chain, fully utilized Qinchuang's original new driving platform, combined with the company's own talent advantages, and collaborated with domestic and foreign research institutes to target cutting-edge fields and forward-looking technologies in the industry. Through technological innovation, Tianrui Silicon Materials has empowered the company to develop high-quality, and has won 5 scientific and technological awards, There are 4 awards for the "Three New and Three Small" (new technology, new process, new materials and small inventions, small creations, and small transformations) innovation competition, 10 technology patents have been applied for, 7 science and technology projects have been successfully applied for, and 5 standards have been included in the national industry standard plan for 2022. Currently, there are 72 technology patents. It has been successively awarded the titles of "National High tech Enterprise", "National Intellectual Property Enterprise", "Shaanxi Province Intellectual Property Advantage Enterprise", "Shaanxi Province Gazelle Enterprise", "Shaanxi Province 2021 Famous Brand Enterprise", and "Third Batch of Intelligent Photovoltaic Pilot Demonstration Enterprises". The produced granular polysilicon, ultra-pure electronic grade silane gas, and electronic grade polysilicon products have been recognized as key new products in Shaanxi Province.