CN115536026B - Multi-compensation multi-row polysilicon impurity removing process - Google Patents
Multi-compensation multi-row polysilicon impurity removing process Download PDFInfo
- Publication number
- CN115536026B CN115536026B CN202211166069.2A CN202211166069A CN115536026B CN 115536026 B CN115536026 B CN 115536026B CN 202211166069 A CN202211166069 A CN 202211166069A CN 115536026 B CN115536026 B CN 115536026B
- Authority
- CN
- China
- Prior art keywords
- trichlorosilane
- tower
- purity
- impurities
- temperature
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 239000012535 impurity Substances 0.000 title claims abstract description 56
- 229910021420 polycrystalline silicon Inorganic materials 0.000 title claims abstract description 43
- 229920005591 polysilicon Polymers 0.000 title claims abstract description 41
- 238000000034 method Methods 0.000 title claims abstract description 38
- ZDHXKXAHOVTTAH-UHFFFAOYSA-N trichlorosilane Chemical compound Cl[SiH](Cl)Cl ZDHXKXAHOVTTAH-UHFFFAOYSA-N 0.000 claims abstract description 101
- 239000005052 trichlorosilane Substances 0.000 claims abstract description 100
- 238000009835 boiling Methods 0.000 claims abstract description 17
- 238000006722 reduction reaction Methods 0.000 claims description 37
- 229910052739 hydrogen Inorganic materials 0.000 claims description 32
- 239000001257 hydrogen Substances 0.000 claims description 32
- 238000000746 purification Methods 0.000 claims description 32
- 239000000463 material Substances 0.000 claims description 30
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 28
- 238000000926 separation method Methods 0.000 claims description 21
- 238000006243 chemical reaction Methods 0.000 claims description 17
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 9
- 239000011863 silicon-based powder Substances 0.000 claims description 8
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 6
- 229910000041 hydrogen chloride Inorganic materials 0.000 claims description 6
- IXCSERBJSXMMFS-UHFFFAOYSA-N hydrogen chloride Substances Cl.Cl IXCSERBJSXMMFS-UHFFFAOYSA-N 0.000 claims description 6
- 230000035484 reaction time Effects 0.000 claims description 6
- 238000004821 distillation Methods 0.000 claims description 4
- 229910052796 boron Inorganic materials 0.000 claims description 3
- 229910052698 phosphorus Inorganic materials 0.000 claims description 3
- 239000000047 product Substances 0.000 abstract description 10
- 238000012946 outsourcing Methods 0.000 abstract description 7
- 239000013589 supplement Substances 0.000 abstract description 6
- 238000009776 industrial production Methods 0.000 abstract description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 16
- 239000007789 gas Substances 0.000 description 10
- 230000015572 biosynthetic process Effects 0.000 description 8
- 238000003786 synthesis reaction Methods 0.000 description 8
- 239000000428 dust Substances 0.000 description 6
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 4
- 150000002431 hydrogen Chemical class 0.000 description 4
- 239000007788 liquid Substances 0.000 description 4
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 3
- 239000010949 copper Substances 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 238000009833 condensation Methods 0.000 description 2
- 230000005494 condensation Effects 0.000 description 2
- 239000002826 coolant Substances 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 238000002386 leaching Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000012528 membrane Substances 0.000 description 2
- 229910052763 palladium Inorganic materials 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 239000000377 silicon dioxide Substances 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 239000002912 waste gas Substances 0.000 description 2
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- YGZSVWMBUCGDCV-UHFFFAOYSA-N chloro(methyl)silane Chemical group C[SiH2]Cl YGZSVWMBUCGDCV-UHFFFAOYSA-N 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000006298 dechlorination reaction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000005984 hydrogenation reaction Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- RLOWWWKZYUNIDI-UHFFFAOYSA-N phosphinic chloride Chemical compound ClP=O RLOWWWKZYUNIDI-UHFFFAOYSA-N 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 238000004062 sedimentation Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/02—Silicon
- C01B33/037—Purification
- C01B33/039—Purification by conversion of the silicon into a compound, optional purification of the compound, and reconversion into silicon
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/10—Process efficiency
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Silicon Compounds (AREA)
Abstract
The invention provides a process for removing polysilicon impurities by multiple supplements and multiple rows, which belongs to the technical field of polysilicon industrial production, and particularly replaces trichlorosilane with low content of the supplemented impurities with high and low boiling towers to recycle the trichlorosilane in the system, and then discharges the trichlorosilane containing impurities such as P and the like which are not returned in the system from the high and low boiling towers to the system for selling the photovoltaic grade trichlorosilane, thereby fundamentally solving the problem that the impurities such as P and the like in products cannot be removed, and simultaneously making up the outsourcing cost of the trichlorosilane which needs outsourcing during the operation of polysilicon enterprises.
Description
Technical Field
The invention belongs to the technical field of polysilicon industrial production, and particularly relates to a process for removing polysilicon impurities in multiple-supplementing multiple rows.
Background
Raw material metallic silicon and impurity such as B, P, C carried by outsourced trichlorosilane react at high temperature of cold hydrogenation to generate BCl 3 ，PCl 3 ，PCl 5 ，POCl 3 Methyl chlorosilane and other impurity forms. Impurities are discharged into a high-low boiling tower through five-stage rectification and purification, and high-purity trichlorosilane enters a reducing furnace to be reduced at 1050 ℃ to produce high-purity polysilicon.
However, the trichlorosilane entering the high-low boiling tower contains impurities such as P and the like, the impurities are continuously enriched in the high-low boiling tower of the system, and the part of the material is recycled as much as possible in order to reduce the loss of the material in a common polysilicon enterprise, so that the part of the trichlorosilane containing the enriched P impurities is easily returned to the high-purity material, the instability of impurity fluctuation is caused, and the quality of the product is finally influenced. Therefore, the multi-supplement multi-row process is adopted, on one hand, the outsourcing cost of the trichlorosilane which needs outsourcing during the operation of a polysilicon enterprise is reduced, on the other hand, the trichlorosilane with the few impurity contents which is added more is used for effectively replacing the trichlorosilane which is recycled to the system in the high-low boiling tower, the trichlorosilane which does not recycle to the system in the high-low boiling tower and contains the P and other impurities is discharged out of the system for the outsourcing of the photovoltaic grade trichlorosilane, and the problem that the P and other impurities in the product cannot be removed is fundamentally solved.
Chinese patent application 201410260437.9 discloses a system and method for preparing polycrystalline silicon and a method and system for purifying trichlorosilane. Wherein, the method for preparing the polysilicon comprises the following steps: (1) Heating hydrogen and trichlorosilane respectively by using hot water so as to obtain cooled hot water and heat-treated hydrogen and trichlorosilane, (2) carrying out reduction reaction on the heat-treated hydrogen and the heat-treated trichlorosilane in a reduction furnace so as to obtain polycrystalline silicon and reduction tail gas, and carrying out water cooling on the reduction furnace so as to obtain first hot water; (3) Heating the cooled hot water by utilizing the reduction tail gas to obtain second hot water; mixing the first hot water and the second hot water to obtain hot water of a reduction working section, and using the hot water of the reduction working section as a heat source of a rectifying tower for purifying trichlorosilane so as to obtain return water of the purification working section; wherein, the first hot water and the second hot water are both 145-155 ℃. By utilizing the method, the water resource and the heat energy can be recycled, so that the energy consumption is remarkably saved. However, the above patent only has hot water for reaction heat and heat recycling, and the technology similar to flash evaporation, heat pump and the like in production utilizes the reduced hot water, so that the purity is not greatly improved.
Chinese patent application 201110200460.5 discloses a method for purifying and treating polysilicon by reducing trichlorosilane. Two groups of metal palladium composite membrane hydrogen purifiers connected in series are adopted to purify the trichlorosilane reduction recycle hydrogen, wherein the first group of metal palladium composite membrane hydrogen purifiers are relatively large, and the purified ultrapure hydrogen (H) 2 Purity > 99.999%) is returned to the reduction furnace for the feed gas for trichlorosilane reduction, while the second set of hydrogen purifiers is relatively small, purifying the treated high purity hydrogen (H) 2 Purity-99.999%) as feed gas. The method can purify and process the recovery rate of the recycle hydrogenUp to 99%. When the hydrogen chloride content in the recycled hydrogen is high, the necessary dechlorination measures are needed to reduce the HCl content to below 0.5 ppm. The hydrogen purified by the method is used for producing the polysilicon, so that the purity and quality of the polysilicon product can be obviously improved, and the method has obvious energy-saving and emission-reducing effects. The reaction is high-temperature reduction of trichlorosilane and hydrogen, and the mass ratio of the trichlorosilane is large, so that the purification of the trichlorosilane is a main purification means.
Therefore, it is necessary to explore a simple and low-cost multi-supplement multi-row polysilicon impurity removal process.
Disclosure of Invention
Aiming at the problems existing in the prior art, the invention provides a process for removing polysilicon impurities in multiple-supplementing multiple-row mode, which discharges impurities such as P and the like which are repeatedly circulated and enriched in a high-low boiling tower out of the system, fundamentally solves the problems that P impurities of a polysilicon system are difficult to remove and the like, and finally improves the quality of polysilicon products.
In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:
firstly, a process for removing polysilicon impurities in multiple-supplementing multiple rows is provided, which comprises the following steps:
(1) Reacting hydrogen chloride with silicon powder to generate crude trichlorosilane;
(2) Coarse separation and multistage purification are carried out on the crude trichlorosilane obtained in the step (1) to obtain high-purity trichlorosilane and impurity-containing materials;
(3) Carrying out reduction reaction on the high-purity trichlorosilane obtained in the step (2) to obtain a high-purity polysilicon material;
(4) And (3) primarily purifying the impurity-containing material obtained in the step (2), and then performing the reduction reaction of the step (3) again on the high-purity trichlorosilane obtained after the multi-stage purification to prepare the high-purity polysilicon material.
Further, the reduction reaction in the step (3) is specifically: the high-purity trichlorosilane reacts at the high temperature of 1050 ℃ by a CVD sedimentation method to produce high-purity polysilicon material.
Further, the impurity in the crude trichlorosilane in the step (1) comprises one or more of B (boron), P (phosphorus), fe (iron), ni (nickel) and Cu (copper); wherein the mass fraction of B is 4.5-5.5ppm, the mass fraction of P is 2.5-3.5ppm, and the mass fraction of three metal impurities of Fe, ni and Cu is 6-8ppm.
Further, the mass percentage of trichlorosilane in the crude trichlorosilane in the step (1) is 85-95%, preferably 91%.
Further, the temperature of the reaction in step (1) is 280 to 300 ℃.
Further, the rough separation in the step (2) is specifically: the temperature of the feeding preheater of the rough separation tower is 65-105 ℃, the temperature of the reboiler of the tower bottom is 130-140 ℃, the temperature of the condenser at the top of the tower is 40-70 ℃, and the working pressure is 0.2-0.4Mpa.
Further, the multi-stage purification in the step (2) is five-stage distillation, and the five-stage distillation is specifically: a five-stage rectifying tower is divided into a heavy component removal tower and a light component removal tower, and single-component trichlorosilane is repeatedly removed under the pressure of 0.15-0.25Mpa. The column temperature is similar to that of the crude separation column.
Further, the mass percentage of trichlorosilane in the product obtained after the rough separation in the step (2) is more than 99 percent.
Further, the mass percentage of the trichlorosilane in the high-purity trichlorosilane in the step (2) is 99.999 percent.
Further, the specific process of the reduction reaction in the step (3) is as follows: introducing high-purity trichlorosilane into a reducing furnace, and simultaneously introducing hydrogen for reaction, wherein the molar ratio of the hydrogen to the trichlorosilane is 4-5:1.
further, the temperature of the reaction is 1000-1100 ℃, preferably 1080-1100 ℃; the reaction time is 70-90h.
Finally, an application of the process in polysilicon impurity removal is provided.
The technical solution of the present application may be briefly described as follows: all crude trichlorosilane produced by the trichlorosilane production device is introduced into a crude separation tower to separate purer trichlorosilane; the purer trichlorosilane is discharged into the high-low boiling tower through the five-stage rectifying system, so that the load of the five-stage rectifying tower and the load of the high-low boiling tower are kept unchanged, the trichlorosilane with more supplement and less impurity content effectively replaces the trichlorosilane which is recycled back into the system in the high-low boiling tower, and the trichlorosilane containing the P and other impurities which is not recycled into the system in the high-low boiling tower is discharged out of the system for selling the photovoltaic-grade trichlorosilane, thereby fundamentally solving the problems that the P and other impurities in products are enriched and cannot be discharged out of the system.
In some specific embodiments, the multi-replenishment multi-row polysilicon impurity removal process comprises the following steps:
(1) The preparation process of the crude trichlorosilane comprises the following steps: the dried hydrogen chloride gas firstly passes through a buffer tank, then enters a synthesis furnace through a rotameter at a proper flow rate, and reacts with silicon powder dried by a dryer at a temperature of 280-300 ℃; in the reaction process, the temperature of the synthesis furnace can be regulated at any time. The silicon powder is continuously added into the synthesis furnace by a feeder to supplement the silicon powder consumed in the reaction process. The trichlorosilane gas generated by the reaction is discharged from the upper part of the synthesis furnace, and then the entrained dust is removed by a cyclone filter dust remover (the dust enters a silica powder dryer for use), and then enters a tube condenser for condensation into liquid, and the temperature of the coolant of the tube condenser is about 40 ℃ below zero; the condensate is put into a storage tank through a gauge, and the uncondensed gas is sent to a waste gas leaching tower through a liquid sealer for treatment and then is discharged into the atmosphere.
(2) Coarse separation and multistage purification are carried out on the crude trichlorosilane obtained in the step (1) to obtain high-purity trichlorosilane and impurity-containing materials; wherein the temperature of the feeding preheater of the rough separation tower is 65-105 ℃, the temperature of the reboiler of the tower kettle is 130-140 ℃, the temperature of the condenser at the top of the tower is 40-70 ℃, and the working pressure is 0.2-0.4Mpa; the multistage purification is specifically a five-stage rectifying tower which is divided into a heavy component removal tower and a light component removal tower, and the mild and coarse separation tower is similar, and the single-component trichlorosilane is repeatedly removed under the pressure of 0.2Mpa.
(3) The high-purity trichlorosilane obtained in the step (2) is subjected to reduction reaction to obtain high-purity polysilicon material, and the specific process of the reduction reaction is as follows: introducing high-purity trichlorosilane into a reducing furnace at a flow rate of 110-130t/h, wherein the reaction temperature of the reducing furnace is 1080-1100 ℃, the reaction time is 70-90h, the pressure is 4-5bar, meanwhile, hydrogen is introduced, the purity of the hydrogen is 99.99%, the flow rate of hydrogen is 5-6t/h, and the molar ratio of the hydrogen to the trichlorosilane is 4-5:1, a reducing furnace with the specification of 40 pairs of rod reducing furnaces;
(4) The impurity-containing material obtained in the step (2) is subjected to preliminary purification, and then the high-purity trichlorosilane obtained after multistage purification is subjected to the reduction reaction of the step (3) again to prepare a high-purity polysilicon material; the multi-stage purification step is the same as the step (2).
Compared with the prior art, the invention has the following beneficial effects:
(1) The process provided by the invention compensates for the reduced outsourcing cost of trichlorosilane which needs outsourcing during the operation of a polysilicon enterprise;
(2) The process provided by the invention can effectively reduce P and other impurities which are enriched in the high-low boiling tower kettle and cannot be carried out of the system, thus fundamentally solving the problem that P and other impurities cannot be removed, greatly improving the elasticity of the system for treating impurities and greatly improving the quality of polysilicon products;
(3) The process provided by the invention does not increase the load of system rectification on the whole, and the trichlorosilane containing P and other impurities which do not return to the system in the high-low boiling tower is discharged out of the system for selling photovoltaic grade trichlorosilane, so that the cost increase caused by the outside is reduced.
Drawings
Fig. 1 is a schematic diagram of a multi-replenishment multi-row polysilicon impurity removal process.
Detailed Description
It is to be noted that the raw materials used in the present invention are all common commercial products, and the sources thereof are not particularly limited.
The schematic structure of the process involved in the present application is shown in fig. 1.
Example 1
(1) The preparation process of the crude trichlorosilane comprises the following steps: the dried hydrogen chloride gas firstly passes through a buffer tank, then enters a synthesis furnace through a rotameter at a proper flow rate, and reacts with silicon powder dried by a dryer at a temperature of 280-300 ℃; in the reaction process, the temperature of the synthesis furnace can be regulated at any time. The silicon powder is continuously added into the synthesis furnace by a feeder to supplement the silicon powder consumed in the reaction process. The trichlorosilane gas generated by the reaction is discharged from the upper part of the synthesis furnace, and then the entrained dust is removed by a cyclone filter dust remover (the dust enters a silica powder dryer for use), and then enters a tube condenser for condensation into liquid, and the temperature of the coolant of the tube condenser is about 40 ℃ below zero; the condensate is put into a storage tank through a gauge, and the uncondensed gas is sent to a waste gas leaching tower through a liquid sealer for treatment and then is discharged into the atmosphere.
(2) Coarse separation and multistage purification are carried out on the crude trichlorosilane obtained in the step (1) to obtain high-purity trichlorosilane and impurity-containing materials; wherein the temperature of the feeding preheater of the rough separation tower is 80-90 ℃, the temperature of the reboiler of the tower kettle is 130-140 ℃, the temperature of the condenser at the top of the tower is 50-60 ℃, and the working pressure is 0.3Mpa; the multistage purification is specifically a five-stage rectifying tower which is divided into a heavy component removal tower and a light component removal tower, and the mild and coarse separation tower is similar, and the single-component trichlorosilane is repeatedly removed under the pressure of 0.2Mpa.
(3) The high-purity trichlorosilane obtained in the step (2) is subjected to reduction reaction to obtain high-purity polysilicon material, and the specific process of the reduction reaction is as follows: the high-purity trichlorosilane is introduced into a reducing furnace at a flow rate of 110-130t/h, the reaction temperature of the reducing furnace is 1080 ℃, the reaction time is 80h, the pressure is 4bar, meanwhile, hydrogen is introduced, the purity of the hydrogen is 99.99%, the flow rate of the hydrogen is 5-6t/h, and the molar ratio of the hydrogen to the trichlorosilane is 4:1, the specification of the reduction furnace is 40 pairs of rod reduction furnaces.
(4) The impurity-containing material obtained in the step (2) is subjected to preliminary purification, and then the high-purity trichlorosilane obtained after multistage purification is subjected to the reduction reaction of the step (3) again to prepare a high-purity polysilicon material; the multi-stage purification step is the same as the step (2).
Example 2
(1) Step (1) was performed as in example 1.
(2) Coarse separation and multistage purification are carried out on the crude trichlorosilane obtained in the step (1) to obtain high-purity trichlorosilane and impurity-containing materials; wherein the temperature of the feeding preheater of the rough separation tower is 65-75 ℃, the temperature of the reboiler of the tower bottom is 130-140 ℃, the temperature of the condenser at the top of the tower is 60-70 ℃, and the working pressure is 0.4Mpa; the multistage purification is specifically a five-stage rectifying tower which is divided into a heavy component removal tower and a light component removal tower, and the mild and coarse separation tower is similar, and the single-component trichlorosilane is repeatedly removed under the pressure of 0.2Mpa.
(3) The high-purity trichlorosilane obtained in the step (2) is subjected to reduction reaction to obtain high-purity polysilicon material, and the specific process of the reduction reaction is as follows: the high-purity trichlorosilane is introduced into a reducing furnace at a flow rate of 110-130t/h, the reaction temperature of the reducing furnace is 1100 ℃, the reaction time is 70h, the pressure is 5bar, meanwhile, hydrogen is introduced, the purity of the hydrogen is 99.99%, the flow rate of the hydrogen is 5-6t/h, and the molar ratio of the hydrogen to the trichlorosilane is 5:1, the specification of the reduction furnace is 40 pairs of rod reduction furnaces.
(4) The impurity-containing material obtained in the step (2) is subjected to preliminary purification, and then the high-purity trichlorosilane obtained after multistage purification is subjected to the reduction reaction of the step (3) again to prepare a high-purity polysilicon material; the multi-stage purification step is the same as the step (2).
Example 3
(1) Step (1) was performed as in example 1.
(2) Coarse separation and multistage purification are carried out on the crude trichlorosilane obtained in the step (1) to obtain high-purity trichlorosilane and impurity-containing materials; wherein the temperature of the feeding preheater of the rough separation tower is 95-105 ℃, the temperature of the reboiler of the tower bottom is 130-140 ℃, the temperature of the condenser at the top of the tower is 40-50 ℃, and the working pressure is 0.2Mpa; the multistage purification is specifically a five-stage rectifying tower which is divided into a heavy component removal tower and a light component removal tower, and the mild and coarse separation tower is similar, and the single-component trichlorosilane is repeatedly removed under the pressure of 0.2Mpa.
(3) The high-purity trichlorosilane obtained in the step (2) is subjected to reduction reaction to obtain high-purity polysilicon material, and the specific process of the reduction reaction is as follows: the high-purity trichlorosilane is introduced into a reducing furnace at a flow rate of 110-130t/h, the reaction temperature of the reducing furnace is 1000 ℃, the reaction time is 90h, the pressure is 4bar, meanwhile, hydrogen is introduced, the purity of the hydrogen is 99.99%, the flow rate of the hydrogen is 5-6t/h, and the molar ratio of the hydrogen to the trichlorosilane is 4:1, the specification of the reduction furnace is 40 pairs of rod reduction furnaces.
(4) The impurity-containing material obtained in the step (2) is subjected to preliminary purification, and then the high-purity trichlorosilane obtained after multistage purification is subjected to the reduction reaction of the step (3) again to prepare a high-purity polysilicon material; the multi-stage purification step is the same as the step (2).
Experimental example
The high purity polysilicon material products obtained in examples 1 to 3 were subjected to a P impurity content test, and the test results are shown in table 1.
Table 1 test results table
Note that: p removal efficiency = [ (P impurity content of high purity trichlorosilane-P impurity content of high purity polysilicon material)/P impurity content of high purity trichlorosilane ] ×100%
Finally, it should be noted that the above description is only for illustrating the technical solution of the present invention, and not for limiting the scope of the present invention, and that the simple modification and equivalent substitution of the technical solution of the present invention can be made by those skilled in the art without departing from the spirit and scope of the technical solution of the present invention.
Claims (7)
1. The process for removing polysilicon impurities by multiple-supplementing multiple rows is characterized by comprising the following steps of:
(1) Reacting hydrogen chloride with silicon powder to generate crude trichlorosilane;
(2) Coarse separation and multistage purification are carried out on the crude trichlorosilane obtained in the step (1) to obtain high-purity trichlorosilane and impurity-containing materials;
(3) Carrying out reduction reaction on the high-purity trichlorosilane obtained in the step (2) to obtain a high-purity polysilicon material;
(4) The impurity-containing material obtained in the step (2) is subjected to preliminary purification, and then the high-purity trichlorosilane obtained after multistage purification is subjected to the reduction reaction of the step (3) again to prepare a high-purity polysilicon material;
the multi-stage purification in the step (2) is five-stage distillation, and the five-stage distillation is specifically: rectifying a total five-stage tower, which is divided into a heavy component removal and light component removal, wherein the pressure is 0.15-0.25MPa for single-component trichlorosilane;
step (2) the multistage purification: the trichlorosilane with the P impurities is discharged into a high-low boiling tower through a five-stage rectifying system, the trichlorosilane with the low content of the supplementary impurities is used for replacing the trichlorosilane in the high-low boiling tower, which is recycled back into the system, under the condition that the load of the five-stage rectifying tower and the load of the high-low boiling tower are kept unchanged, and the trichlorosilane with the P impurities, which is not recycled back into the system, is discharged out of the system;
the specific process of the reduction reaction in the step (3) is as follows: introducing high-purity trichlorosilane into a reducing furnace, and simultaneously introducing hydrogen for reaction, wherein the molar ratio of the hydrogen to the trichlorosilane is 4:1, the temperature of the reduction reaction is 1080 ℃, and the reaction time is 80h.
2. The process of claim 1, wherein the impurity in the crude trichlorosilane in step (1) comprises one or more of B, P, fe, ni, cu.
3. The process according to claim 1, wherein the mass percentage of trichlorosilane in the crude trichlorosilane in the step (1) is 85 to 95%.
4. The process according to claim 1, wherein the temperature of the reaction in step (1) is 280-300 ℃.
5. The process according to claim 1, wherein the coarse fraction in step (2) is specifically: the temperature of the feeding preheater of the rough separation tower is 65-105 ℃, the temperature of the reboiler of the tower bottom is 130-140 ℃, the temperature of the condenser at the top of the tower is 40-70 ℃, and the working pressure is 0.2-0.4MPa.
6. The process according to claim 1, wherein the mass percentage of trichlorosilane in the product obtained after the rough separation in the step (2) is 99% or more.
7. Use of the process of any one of claims 1-6 for polysilicon impurity removal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211166069.2A CN115536026B (en) | 2022-09-23 | 2022-09-23 | Multi-compensation multi-row polysilicon impurity removing process |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211166069.2A CN115536026B (en) | 2022-09-23 | 2022-09-23 | Multi-compensation multi-row polysilicon impurity removing process |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115536026A CN115536026A (en) | 2022-12-30 |
| CN115536026B true CN115536026B (en) | 2024-01-12 |
Family
ID=84730576
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211166069.2A Active CN115536026B (en) | 2022-09-23 | 2022-09-23 | Multi-compensation multi-row polysilicon impurity removing process |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115536026B (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101538044A (en) * | 2009-04-21 | 2009-09-23 | 天津大学 | System for separating and purifying trichlorosilane in production process of polysilicon and operation method thereof |
| WO2012101052A1 (en) * | 2011-01-25 | 2012-08-02 | Wacker Chemie Ag | Cleaning dry residues of the direct synthesis of alkylchlorosilanes |
| CN114014324A (en) * | 2021-12-21 | 2022-02-08 | 新疆大全新能源股份有限公司 | Distillation process of trichlorosilane |
-
2022
- 2022-09-23 CN CN202211166069.2A patent/CN115536026B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101538044A (en) * | 2009-04-21 | 2009-09-23 | 天津大学 | System for separating and purifying trichlorosilane in production process of polysilicon and operation method thereof |
| WO2012101052A1 (en) * | 2011-01-25 | 2012-08-02 | Wacker Chemie Ag | Cleaning dry residues of the direct synthesis of alkylchlorosilanes |
| CN114014324A (en) * | 2021-12-21 | 2022-02-08 | 新疆大全新能源股份有限公司 | Distillation process of trichlorosilane |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115536026A (en) | 2022-12-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101704524B (en) | Production device and method of high purity trichlorosilane by using heat pump distillation | |
| CN101538044B (en) | System for separating and purifying trichlorosilane in production process of polysilicon and operation method thereof | |
| CN102642839B (en) | Processing process of industrial grade silicon tetrachloride | |
| CN101327912A (en) | Method for reclaiming hydrogen from tail gas from polysilicon production | |
| CN113247908B (en) | Separation method and separation device for chlorosilane in polysilicon production | |
| JP2012533515A (en) | Method and apparatus for purifying trichlorosilane | |
| CN101357286B (en) | Method for recovering dichloro-dihydro silicon from off-gas generated from the production of polycrystalline silicon | |
| CN115536026B (en) | Multi-compensation multi-row polysilicon impurity removing process | |
| CN219730550U (en) | Chlorosilane rectifying and impurity removing system in polysilicon production | |
| CN101372336B (en) | Method for preparing polysilicon | |
| CN102030335B (en) | Method and device for removing boron impurity in chlorosilane system by rectification through double-tower thermocouple reaction | |
| CN217458845U (en) | System for increasing reaction efficiency of polycrystalline silicon reduction furnace | |
| CN215822386U (en) | Process system for improving productivity of polysilicon rectification and reverse disproportionation | |
| CN114671405A (en) | Process for preparing high-purity hydrogen chloride from by-product hydrochloric acid in methane chloride process | |
| CN101372335B (en) | Method for preparing polysilicon | |
| CN211546377U (en) | Phosphate ester preparation equipment | |
| CN115557503B (en) | Method for producing polycrystalline silicon and silane coupling agent in multiple-compensation multiple rows | |
| CN112645976A (en) | Method for preparing methyl chlorosilane organic silicon by using tail gas FTrPSA (fluorine-doped polysilicon-fluoride) in growth process of chlorine-based CVD (chemical vapor deposition) crystal film | |
| CN101357287B (en) | Method for recovering hydrogen chloride from off-gas generated from the production of polycrystalline silicon | |
| CN219764529U (en) | Chlorosilane rectification system with four coupled towers | |
| CN220283634U (en) | Material comprehensive treatment system for polysilicon rectification process | |
| CN116173536B (en) | Polysilicon rectifying system and rectifying method | |
| CN112624194B (en) | Method for preparing high-purity hafnium tetrachloride by one-step method | |
| CN219603257U (en) | Sulfuric acid treatment system for hydrogen fluoride production | |
| CN220310400U (en) | Three-silicon reverse disproportionation supply system for polycrystalline silicon production |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |