CN220166329U - Silica powder pulverizing system and silica treatment system - Google Patents
Silica powder pulverizing system and silica treatment system Download PDFInfo
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- CN220166329U CN220166329U CN202320375897.0U CN202320375897U CN220166329U CN 220166329 U CN220166329 U CN 220166329U CN 202320375897 U CN202320375897 U CN 202320375897U CN 220166329 U CN220166329 U CN 220166329U
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- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 title claims abstract description 178
- 239000000843 powder Substances 0.000 title claims abstract description 128
- 239000000377 silicon dioxide Substances 0.000 title claims abstract description 87
- 238000010298 pulverizing process Methods 0.000 title claims abstract description 38
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims abstract description 132
- 239000000428 dust Substances 0.000 claims abstract description 93
- 239000011863 silicon-based powder Substances 0.000 claims abstract description 86
- 238000000926 separation method Methods 0.000 claims abstract description 60
- 238000001035 drying Methods 0.000 claims abstract description 13
- 238000005660 chlorination reaction Methods 0.000 claims description 25
- 229910052799 carbon Inorganic materials 0.000 claims description 21
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 20
- 229910021487 silica fume Inorganic materials 0.000 claims description 20
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 claims description 19
- 239000000460 chlorine Substances 0.000 claims description 19
- 229910052801 chlorine Inorganic materials 0.000 claims description 19
- 239000002245 particle Substances 0.000 claims description 10
- 238000007599 discharging Methods 0.000 claims description 2
- 238000007780 powder milling Methods 0.000 claims 1
- 229910052710 silicon Inorganic materials 0.000 abstract description 43
- 239000010703 silicon Substances 0.000 abstract description 43
- 239000007789 gas Substances 0.000 description 139
- FDNAPBUWERUEDA-UHFFFAOYSA-N silicon tetrachloride Chemical compound Cl[Si](Cl)(Cl)Cl FDNAPBUWERUEDA-UHFFFAOYSA-N 0.000 description 114
- 239000007788 liquid Substances 0.000 description 113
- 238000004519 manufacturing process Methods 0.000 description 83
- VSCWAEJMTAWNJL-UHFFFAOYSA-K aluminium trichloride Chemical compound Cl[Al](Cl)Cl VSCWAEJMTAWNJL-UHFFFAOYSA-K 0.000 description 58
- 229910021420 polycrystalline silicon Inorganic materials 0.000 description 56
- 239000000126 substance Substances 0.000 description 54
- 230000006872 improvement Effects 0.000 description 52
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 42
- 239000003546 flue gas Substances 0.000 description 41
- 238000000034 method Methods 0.000 description 41
- 229910052725 zinc Inorganic materials 0.000 description 36
- 239000011701 zinc Substances 0.000 description 36
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 35
- 239000002994 raw material Substances 0.000 description 34
- 239000008247 solid mixture Substances 0.000 description 34
- 229920005591 polysilicon Polymers 0.000 description 33
- 238000003860 storage Methods 0.000 description 30
- 230000007246 mechanism Effects 0.000 description 27
- 238000010992 reflux Methods 0.000 description 26
- 239000007787 solid Substances 0.000 description 26
- XJDNKRIXUMDJCW-UHFFFAOYSA-J titanium tetrachloride Chemical compound Cl[Ti](Cl)(Cl)Cl XJDNKRIXUMDJCW-UHFFFAOYSA-J 0.000 description 23
- 229910021578 Iron(III) chloride Inorganic materials 0.000 description 22
- RBTARNINKXHZNM-UHFFFAOYSA-K iron trichloride Chemical compound Cl[Fe](Cl)Cl RBTARNINKXHZNM-UHFFFAOYSA-K 0.000 description 22
- JIAARYAFYJHUJI-UHFFFAOYSA-L zinc dichloride Chemical compound [Cl-].[Cl-].[Zn+2] JIAARYAFYJHUJI-UHFFFAOYSA-L 0.000 description 22
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 20
- 238000006477 desulfuration reaction Methods 0.000 description 16
- 230000023556 desulfurization Effects 0.000 description 16
- 229910000519 Ferrosilicon Inorganic materials 0.000 description 15
- 238000001914 filtration Methods 0.000 description 13
- 238000005868 electrolysis reaction Methods 0.000 description 12
- 238000006722 reduction reaction Methods 0.000 description 12
- KZBUYRJDOAKODT-UHFFFAOYSA-N Chlorine Chemical compound ClCl KZBUYRJDOAKODT-UHFFFAOYSA-N 0.000 description 11
- 235000005074 zinc chloride Nutrition 0.000 description 11
- 239000011592 zinc chloride Substances 0.000 description 11
- 230000009467 reduction Effects 0.000 description 10
- 238000003723 Smelting Methods 0.000 description 9
- 229910052751 metal Inorganic materials 0.000 description 9
- 239000002184 metal Substances 0.000 description 9
- 238000000859 sublimation Methods 0.000 description 9
- 238000006243 chemical reaction Methods 0.000 description 8
- 229910052757 nitrogen Inorganic materials 0.000 description 8
- 230000008022 sublimation Effects 0.000 description 8
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 7
- 239000002918 waste heat Substances 0.000 description 7
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 6
- 238000010438 heat treatment Methods 0.000 description 6
- 238000002844 melting Methods 0.000 description 6
- 230000008569 process Effects 0.000 description 6
- 238000000746 purification Methods 0.000 description 6
- 239000003054 catalyst Substances 0.000 description 5
- 229910001873 dinitrogen Inorganic materials 0.000 description 5
- 230000008018 melting Effects 0.000 description 5
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 description 4
- 239000013078 crystal Substances 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 238000002156 mixing Methods 0.000 description 4
- 229910000077 silane Inorganic materials 0.000 description 4
- 229910021529 ammonia Inorganic materials 0.000 description 3
- 239000003638 chemical reducing agent Substances 0.000 description 3
- 239000000571 coke Substances 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- 230000007613 environmental effect Effects 0.000 description 3
- 239000000945 filler Substances 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 238000005507 spraying Methods 0.000 description 3
- 239000004408 titanium dioxide Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 238000004321 preservation Methods 0.000 description 2
- 230000003134 recirculating effect Effects 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- 235000012239 silicon dioxide Nutrition 0.000 description 2
- 239000002210 silicon-based material Substances 0.000 description 2
- 239000000779 smoke Substances 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- 239000006004 Quartz sand Substances 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 235000011114 ammonium hydroxide Nutrition 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 239000003610 charcoal Substances 0.000 description 1
- 239000003245 coal Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 230000003009 desulfurizing effect Effects 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 238000005189 flocculation Methods 0.000 description 1
- 230000016615 flocculation Effects 0.000 description 1
- 239000003517 fume Substances 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000002386 leaching Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
- 239000002006 petroleum coke Substances 0.000 description 1
- 238000009700 powder processing Methods 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- 239000002023 wood Substances 0.000 description 1
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- Silicon Compounds (AREA)
Abstract
The utility model discloses a silica powder pulverizing system and a silica treatment system. The silica powder pulverizing system comprises: the first crushing equipment is used for crushing raw ore silica into first powder with the granularity less than or equal to 100 mm; the second crushing equipment is used for crushing the first powder into second powder with the granularity less than or equal to 50 mm; the third crushing equipment is used for crushing the second powder into third powder with the granularity less than or equal to 5 mm; a drying device for drying the third powder; the separation equipment is used for separating fine silicon powder with the granularity less than or equal to 1mm from the third powder, and outputting coarse silicon powder and dust-containing gas carrying the fine silicon powder; and the collecting device is used for collecting the fine silicon powder in the dust-containing gas. The utilization rate of silicon resources can be remarkably improved by carrying out special pulverizing treatment on raw ore silica. The pulverizing system has simple structure, low equipment investment cost and extremely strong practicability.
Description
Technical Field
The utility model relates to the technical field of silica, micro silicon powder, ferrosilicon, silicon chloride and polysilicon, in particular to a silica powder pulverizing system and a silica treatment system.
Background
The chemical formula of the silicon dioxide is SiO 2 There are crystalline and amorphous forms. Silica such as quartz, quartz sand and the like existing in nature is collectively referred to as silica. Silica is the main raw material for the production of industrial silicon (i.e. metal silicon powder) and ferrosilicon (i.e. ferrosilicon, also called ferrosilicon). The industrial silicon is prepared by using raw ore silica as raw material, petroleum coke, metallurgical coke, charcoal, wood chip, low ash coal, etc. as reducer, and smelting at high temperature (1800 deg.c) in ore-smelting electric furnace to reduce metal silicon from silica, which is a slag-free buried arc high temperature smelting process. The ferrosilicon is prepared mainly by a carbothermic method, namely raw ore silica, steel scraps and a reducing agent (metallurgical coke is mostly used) are used as raw materials, and silicon subjected to high-temperature reduction at 1500-1800 ℃ is melted in molten iron to form the ferrosilicon, so that the ferrosilicon is an important alloy variety in the smelting industry.
Silica fume is spherical submicron amorphous silica particles with the particle diameter of about 0.3 mu m, which are produced by the reaction of silica in a high temperature area in an ore-smelting electric furnace with a carbonaceous reducing agent in a reducing atmosphere and are quickly oxidized and condensed after SiO, CO and a small amount of metal gas escape. The carbothermic process has low utilization rate of raw ore silica, and the low-value micro silicon powder produced by the carbothermic process accounts for about 40 percent of the weight of the raw ore silica, so that the overall utilization rate of silicon resources is low. In addition, the quality of the micro silicon powder produced by some enterprises in China is poor at present, so that the use amount of the micro silicon powder is not more than 60% of the actual recovery amount, and the national export amount is lower than 20 ten thousand tons, so that the micro silicon powder is accumulated in a large amount, the waste of land resources is caused, and meanwhile, the human health is also harmed to a certain extent.
In order to realize the conversion from spherical silica fume to high-purity spherical silica fume, the purification of silica fume is regarded as the hot spot and the technical difficulty of the current research. The purity of the micro silicon powder is improved, so that the economic additional value of the micro silicon powder can be obviously improved, and the micro silicon powder can be also used in the fields of agriculture, medical treatment and even higher end. In recent years, the application and purification of the silica fume are studied at home and abroad. At present, the silica fume is mainly purified by methods of calcination, acid leaching, alkali dissolution, flocculation and the like. However, the purification research of the micro silicon powder is only a method for expanding the application direction of the micro silicon powder, and the application value of the micro silicon powder is not really exerted.
The flue gas generated in the production of industrial silicon and ferrosilicon by a carbothermic method can meet the requirements of environmental protection emission only by carrying out a series of treatment measures such as collection of micro silicon powder, waste heat recovery, desulfurization and denitrification, but because the denitration is carried out at a low temperature, the catalyst cost is higher and the denitration effect is poorer, no green and efficient treatment means exist at present, and a great number of environmental pollution problems to be solved urgently exist.
The purity of industrial silicon produced by a carbothermic method is generally within 99.9%, and if solar grade polysilicon (purity of 99.9999% and above) is to be prepared, a series of chemical reactions are required to be carried out, such as Siemens method, silane method, metallurgical method and the like, so that the production cost of the polysilicon is relatively high and the production period is relatively long.
Disclosure of Invention
In a first aspect, the present utility model is directed to a method and a system for producing polycrystalline silicon, so as to solve the technical problems of high production cost, long production period and low utilization value of micro silicon powder in the prior art.
In order to achieve the above object of the first aspect, the technical solution of the method for producing polycrystalline silicon provided by the present utility model is as follows:
the production method of the polysilicon comprises the following steps: reacting a silicon raw material, a carbon simple substance and chlorine gas to generate flue gas containing dust, gaseous ferric chloride, gaseous aluminum chloride and gaseous silicon chloride, wherein the silicon raw material is silica powder and/or micro silica powder; carrying out heat exchange treatment on the flue gas; removing dust in the flue gas, and outputting first powder and first dust-free gas; condensing gaseous ferric chloride in the first dust-free gas into solid ferric chloride, and outputting a first gas-solid mixture; carrying out gas-solid separation treatment on the first gas-solid mixture, and outputting second powder and second dust-free gas; condensing gaseous aluminum chloride in the second dust-free gas into solid aluminum chloride, and outputting a second gas-solid mixture; carrying out gas-solid separation treatment on the second gas-solid mixture, and outputting third powder and third dust-free gas; condensing gaseous silicon chloride in the third dust-free gas into liquid silicon chloride, and outputting a first condensate and a first non-condensable gas; liquid silicon chloride is reduced to polysilicon.
As a further improvement of the above-described production method of polycrystalline silicon: reacting silica powder, carbon simple substance and chlorine gas at 1723-2230 ℃ to generate the flue gas; or silica powder, silica fume, carbon simple substance and chlorine react at 1723-2000 deg.c to produce the fume.
As a further improvement of the above-described production method of polycrystalline silicon: the flue gas also contains gaseous titanium chloride, and the production method further comprises the following steps: synchronously condensing gaseous silicon chloride and gaseous titanium chloride in the third dust-free gas, namely, the first condensate liquid also contains liquid titanium chloride; or, firstly condensing gaseous titanium chloride in the third dust-free gas, and outputting a second condensate and a second non-condensable gas; and then condensing the gaseous silicon chloride in the second noncondensable gas into liquid silicon chloride, and outputting the first condensate and the first noncondensable gas.
As a further improvement of the above-described production method of polycrystalline silicon: the temperature of the first dust-free gas is 350-600 ℃; the temperature of the first gas-solid mixture is 230-300 ℃; the temperature of the first non-condensable gas is 0-30 ℃; when the gaseous titanium chloride and the gaseous silicon chloride are synchronously condensed, the temperature of the second gas-solid mixture is 120-165 ℃, preferably 140-165 ℃; when the gaseous titanium chloride and the gaseous silicon chloride are condensed step by step, the temperature of the second gas-solid mixture is 140-165 ℃, and the temperature of the second non-condensable gas is 70-120 ℃.
As a further improvement of the above-described production method of polycrystalline silicon: reacting the micro silicon powder, the carbon simple substance and chlorine gas at 1000-2000 ℃ to generate the flue gas.
As a further improvement of the above-described production method of polycrystalline silicon: the temperature of the first dust-free gas is 350-600 ℃; the temperature of the first gas-solid mixture is 230-300 ℃; the temperature of the second gas-solid mixture is 100-165 ℃; the temperature of the first non-condensable gas is 0-30 ℃.
As a further improvement of the above-described production method of polycrystalline silicon: the method also comprises the steps of carrying out gas-liquid separation treatment on the first non-condensable gas, and outputting a separation liquid and separation gas; the separation gas is refluxed to react with the silicon raw material and the carbon simple substance; the method also comprises the steps of rectifying the first condensate and the separating liquid to purify the liquid silicon chloride; the method further comprises the step of sublimating the second powder to purify aluminum chloride; and further comprises the step of condensing the third dust-free gas when the pressure of the third dust-free gas is 0.08-1.2 MPa.
As a further improvement of the above-described production method of polycrystalline silicon: liquid zinc simple substance is adopted to reduce liquid silicon chloride into polysilicon and zinc chloride.
As a further improvement of the above-described production method of polycrystalline silicon: the production method further comprises the steps of: carrying out electrolytic treatment on zinc chloride, and outputting chlorine and liquid zinc simple substance; reflux chlorine to react with silicon material and carbon simple substance; and refluxing the liquid zinc simple substance to react with the silicon chloride.
As a further improvement of the above-described production method of polycrystalline silicon: the silica powder is obtained by pulverizing raw ore silica, and the granularity of the silica powder is less than or equal to 1mm; the micro silicon powder is collected in flue gas generated when industrial silicon or ferrosilicon alloy is prepared by a carbothermic method, and the density of the micro silicon powder is 0.5-0.7 t/m 3 。
In order to achieve the above object of the first aspect, the present utility model provides a polysilicon production system, which has the following technical scheme:
a first polysilicon production system comprising: the chlorination metallurgical furnace is used for enabling a silicon raw material, a carbon simple substance and chlorine gas to react to generate flue gas containing dust, gaseous ferric chloride, gaseous aluminum chloride and gaseous silicon chloride, wherein the silicon raw material is silica powder and/or micro silicon powder; the first heat exchange equipment is used for carrying out heat exchange treatment on the flue gas; the first dust removing device is used for removing dust in the flue gas and outputting first powder and first dust-free gas; the second heat exchange device is used for condensing gaseous ferric chloride in the first dust-free gas into solid ferric chloride and outputting a first gas-solid mixture; the second dust removing equipment is used for carrying out gas-solid separation treatment on the first gas-solid mixture and outputting second powder and second dust-free gas; the third heat exchange device is used for condensing gaseous aluminum chloride in the second dust-free gas into solid aluminum chloride and outputting a second gas-solid mixture; the third dust removing device is used for carrying out gas-solid separation treatment on the second gas-solid mixture and outputting third powder and third dust-free gas; the fourth heat exchange device is used for condensing gaseous silicon chloride in the third dust-free gas into liquid silicon chloride and outputting first condensate and first non-condensable gas; the reducing furnace is used for enabling the liquid zinc simple substance and the liquid silicon chloride to react to generate polycrystalline silicon and zinc chloride.
As a further improvement of the first polysilicon production system described above: the first heat exchange equipment is a waste heat boiler; the second heat exchange equipment and the third heat exchange equipment adopt a baffling cooler with an ash bin, a part of solid particles generated when dust-free gas moves in a baffling way flow into corresponding dust removal equipment along with the gas-solid mixture, and the other part falls into the ash bin; the fourth heat exchange equipment adopts water cooling equipment; at least a first dust removing device in the first dust removing device, the second dust removing device and the third dust removing device adopts a metal filter element.
As a further improvement of the first polysilicon production system described above: the third heat exchange device is used for condensing the gaseous silicon chloride in the second non-condensable gas into liquid silicon chloride and outputting the first condensate and the first non-condensable gas.
As a further improvement of the first polysilicon production system described above: further comprises: the gas-liquid separation device is used for carrying out gas-liquid separation treatment on the first non-condensable gas and outputting a separation liquid and separation gas; the separated gas reflux mechanism is used for refluxing the separated gas to the chlorination metallurgical furnace; and the rectification equipment is used for rectifying the first condensate and the separation liquid to purify the liquid silicon chloride.
As a further improvement of the first polysilicon production system described above: the first condensate and the first noncondensable gas are jointly stored in a first storage tank, a liquid outlet is formed in the lower portion of the first storage tank, an air outlet is formed in the upper portion of the first storage tank, the air outlet is connected with gas-liquid separation equipment, and a separation liquid outlet of the gas-liquid separation equipment is connected with the first storage tank or connected with a rectifying equipment or a reducing furnace through a pipeline connected in parallel with the liquid outlet.
As a further improvement of the first polysilicon production system described above: further comprises: sublimation equipment for performing sublimation treatment on the third powder to purify aluminum chloride; and the pressurizing equipment is used for pressurizing the third dust-free gas to 0.08-1.2 MPa.
As a further improvement of the first polysilicon production system described above: the device comprises a first dust removing device, a second dust removing device, a third dust removing device, a nitrogen conveying mechanism, a gas flow pipeline and a gas flow pipeline, wherein the first dust removing device, the second dust removing device and the third dust removing device are respectively connected with the first dust removing device, the second dust removing device and the third dust removing device; the nitrogen conveying mechanism comprises a nitrogen buffer tank and heating equipment.
As a further improvement of the first polysilicon production system described above: further comprises: the electrolysis equipment is used for carrying out electrolysis treatment on the zinc chloride and outputting chlorine and liquid zinc simple substances; the chlorine reflux mechanism is used for refluxing chlorine into the chlorination metallurgical furnace; and the zinc simple substance reflux mechanism is used for refluxing the liquid zinc simple substance into the electrolysis equipment.
As a further improvement of the first polysilicon production system described above: the system also comprises a silica powder pulverizing system connected with the chlorination metallurgical furnace and used for pulverizing raw ore into fine silica powder.
As a further improvement of the first polysilicon production system described above: the system also comprises a micro silicon powder collecting system which is connected with the chlorination metallurgical furnace and is used for collecting the flue gas generated when preparing industrial silicon or ferrosilicon by the carbothermic method.
A second polysilicon production system comprising: a production system of silicon chloride for producing a raw material containing liquid silicon chloride; the reduction furnace is used for enabling the liquid zinc simple substance and the liquid silicon chloride to react to generate polycrystalline silicon and zinc chloride; the electrolysis equipment is used for carrying out electrolysis treatment on the zinc chloride and outputting chlorine and liquid zinc simple substances; the chlorine reflux mechanism is used for refluxing chlorine into the silicon chloride production system; and the zinc simple substance reflux mechanism is used for refluxing the liquid zinc simple substance into the electrolysis equipment.
As a further improvement of the production system of the second polysilicon described above: the zinc simple substance reflux mechanism comprises a zinc simple substance storage tank and a pump for drawing liquid zinc simple substance to flow.
As a further improvement of the production system of the second polysilicon described above: the zinc simple substance reflux mechanism further comprises a heat exchange structure for heat preservation or heating of the zinc simple substance storage tank.
As a further improvement of the production system of the second polysilicon described above: the device also comprises a silicon chloride storage tank for storing liquid silicon chloride and a pump for drawing the liquid silicon chloride to flow.
As a further improvement of the production system of the second polysilicon described above: the liquid silicon chloride and the liquid zinc simple substance are mixed in the liquid-liquid mixing device and then are input into the reduction furnace.
As a further improvement of the production system of the second polysilicon described above: and also comprises a melting device for melting the solid zinc raw material into liquid zinc simple substance.
As a further improvement of the production system of the second polysilicon described above: a crystal bed for bearing seed crystals is arranged in the reduction furnace.
As a further improvement of the production system of the second polysilicon described above: the silicon chloride production system comprises a chlorination metallurgical furnace, a reaction device and a reaction device, wherein the chlorination metallurgical furnace is used for enabling a silicon raw material, a carbon simple substance and chlorine gas to react to generate flue gas containing dust, gaseous ferric chloride, gaseous aluminum chloride and gaseous silicon chloride, and the silicon raw material is silica powder and/or micro silicon powder; and the separation and purification mechanism is used for treating the flue gas and outputting a first condensate liquid containing liquid silicon chloride and a first noncondensable gas.
As a further improvement of the production system of the second polysilicon described above: the silicon chloride production system further comprises: the gas-liquid separation device is used for carrying out gas-liquid separation treatment on the first non-condensable gas and outputting a separation liquid containing liquid silicon chloride and the separation gas; and the separation gas reflux mechanism is used for refluxing the separation gas to the chlorination metallurgical furnace.
As a further improvement of the production system of the second polysilicon described above: the device also comprises rectifying equipment for rectifying the first condensate and the separating liquid to purify the liquid silicon chloride.
In the technical solution of the first aspect, the following steps are: the polycrystalline silicon can be directly prepared from the silica powder and/or the micro silicon powder, the process route is obviously shortened and simplified compared with the combined route of a carbothermic method and a Siemens method/a silane method/a metallurgical method, and the production efficiency of the polycrystalline silicon is improved. The polysilicon prepared from the micro silicon powder can maximally improve the utilization value of the micro silicon powder, remarkably improve the utilization rate of silicon resources and remarkably reduce the pollution of the micro silicon powder. The gaseous ferric chloride and the gaseous aluminum chloride in the flue gas are also recycled step by step with higher purity, so that the comprehensive utilization effect of the flue gas is obviously improved.
In a second aspect, the present utility model is directed to a silica powder pulverizing system and a silica treatment system for improving the production efficiency of the method and system for producing polycrystalline silicon according to the first aspect.
In order to achieve the above object in the second aspect, the technical solution of the silica powder pulverizing system provided by the present utility model is as follows:
silica powder pulverizing system includes: the first crushing equipment is used for crushing raw ore silica into first powder with the granularity less than or equal to 100 mm; the second crushing equipment is used for crushing the first powder into second powder with the granularity less than or equal to 50 mm; the third crushing equipment is used for crushing the second powder into third powder with the granularity less than or equal to 5 mm; a drying device for drying the third powder; the separation equipment is used for separating fine silicon powder with the granularity less than or equal to 1mm from the third powder, and outputting coarse silicon powder and dust-containing gas carrying the fine silicon powder; and the collecting device is used for collecting the fine silicon powder in the dust-containing gas.
As a further improvement of the silica powder pulverizing system, the following is adopted: the first crushing apparatus employs a jaw crusher.
As a further improvement of the silica powder pulverizing system, the following is adopted: the second crushing equipment adopts a hammer crusher or a reaction crusher.
As a further improvement of the silica powder pulverizing system, the following is adopted: the third crushing device adopts a ball mill.
As a further improvement of the silica powder pulverizing system, the following is adopted: the drying device adopts a blower for inputting hot air into the third crushing device.
As a further improvement of the silica powder pulverizing system, the following is adopted: the collecting device adopts an explosion-proof bag type dust collector.
As a further improvement of the silica powder pulverizing system, the following is adopted: further comprising a vibratory feeder for conveying raw ore to the first crushing plant.
As a further improvement of the silica powder pulverizing system, the following is adopted: the device also comprises a dump truck, a loader, a bucket, a speed-regulating feeding belt conveyor and a bucket elevator which are used for conveying the second powder to the third crushing equipment.
As a further improvement of the silica powder pulverizing system, the following is adopted: the first powder bin is used for storing fine silicon powder; the device also comprises a pipeline for re-inputting the crude silicon powder into a third crushing device; the device also comprises an induced draft fan and a first chimney, wherein the induced draft fan and the first chimney are used for draft gas discharge and are sequentially connected with the gas outlet of the collecting device.
In order to achieve the above object of the second aspect, the present utility model provides a silica treatment system according to the following technical scheme:
the silica treatment system comprises a chlorination metallurgical furnace for treating silica and/or micro silicon powder, chlorine and carbon simple substance, and the chlorination metallurgical furnace is connected with the fine silicon powder output end of the silica powder pulverizing system.
In the technical scheme of the second aspect, the utilization rate of silicon resources can be remarkably improved by performing special pulverizing treatment on raw ore silica. The pulverizing system has simple structure, low equipment investment cost and extremely strong practicability.
In a third aspect, the utility model mainly aims to provide a micro silicon powder collecting system and a micro silicon powder processing system, so as to solve the technical problems that flue gas generated in the production of industrial silicon and ferrosilicon by a carbothermic method in the prior art is not effectively treated and micro silicon powder is difficult to effectively use.
In order to achieve the above object of the third aspect, the technical solution of the present utility model for a micro silicon powder collecting system is as follows:
the micro silicon powder collecting system is used for collecting micro silicon powder in flue gas generated when industrial silicon or ferrosilicon is prepared by a carbothermic method, and comprises the following components: the first heat exchange equipment is used for reducing the temperature of the flue gas to 260-400 ℃ and outputting first gas; the first heat exchange equipment is connected with a smoke exhaust pipe of the smelting furnace; the filter equipment is used for collecting the silica fume in the first gas and outputting a second gas and a dust body; the encryption equipment is used for carrying out encryption treatment on the dust body and outputting micro silicon powder; the denitration device is used for carrying out denitration treatment on the second gas and outputting third gas; the second heat exchange equipment is used for reducing the temperature of the third gas to 160-200 ℃ and outputting fourth gas; and the desulfurization device is used for carrying out desulfurization treatment on the fourth gas and outputting exhaust gas.
As a further improvement of the above-mentioned micro silicon powder collecting system: the first heat exchange equipment and the second heat exchange equipment both adopt waste heat boilers.
As a further improvement of the above-mentioned micro silicon powder collecting system: and naturally settled dust in the first heat exchange equipment is discharged into the encryption equipment.
As a further improvement of the above-mentioned micro silicon powder collecting system: filtration equipment and denitration equipment adopt filtration denitration integrated device, ash bucket, filter core and denitration catalyst packing layer in the device are distributed in the casing from bottom to top.
As a further improvement of the above-mentioned micro silicon powder collecting system: an ammonia spraying mechanism is arranged on an air inlet pipeline of the filtering and denitration integrated device or between the filter element and the denitration catalyst filler.
As a further improvement of the above-mentioned micro silicon powder collecting system: the filtering equipment adopts a metal filter element.
As a further improvement of the above-mentioned micro silicon powder collecting system: the desulfurization equipment comprises a dry desulfurization tower and a dust remover which are connected in sequence; or the desulfurization apparatus includes a spray tower.
As a further improvement of the above-mentioned micro silicon powder collecting system: the desulfurization device also comprises an induced draft fan and a second chimney, wherein the induced draft fan and the second chimney are used for draft gas discharge and are sequentially connected with the gas outlet of the desulfurization device.
As a further improvement of the above-mentioned micro silicon powder collecting system: the device also comprises a second powder bin for storing the micro silicon powder.
In order to achieve the above object of the third aspect, the technical solution of the present utility model for a micro silicon powder treatment system is as follows:
the micro silicon powder treatment system comprises a chlorination metallurgical furnace for treating silica and/or micro silicon powder, chlorine and carbon simple substance, and the chlorination metallurgical furnace is connected with the micro silicon powder output end of the micro silicon powder collecting system.
In the technical scheme of the third aspect, on one hand, the flue gas reaches the requirement of environmental protection emission through filtration and denitration at a higher temperature, on the other hand, the micro silicon powder is efficiently recovered, and the micro silicon powder is encrypted through encryption equipment, so that the transportation and the utilization of the micro silicon powder are facilitated. The collecting system has the advantages of simple structure, low equipment investment cost and extremely strong practicability.
In a fourth aspect, the present utility model is mainly aimed at providing a production system capable of obtaining silicon chloride with higher purity, so as to solve the technical problems of higher production cost, longer production period and low utilization value of micro silicon powder in the prior art.
In order to achieve the above object of the fourth aspect, the present utility model provides a silicon chloride production system, which has the following technical scheme:
A system for producing silicon chloride comprising: the chlorination metallurgical furnace is used for enabling a silicon raw material, a carbon simple substance and chlorine gas to react to generate flue gas containing dust, gaseous ferric chloride, gaseous aluminum chloride and gaseous silicon chloride, wherein the silicon raw material is silica powder and/or micro silicon powder; the first heat exchange equipment is used for carrying out heat exchange treatment on the flue gas; the first dust removing device is used for removing dust in the flue gas and outputting first powder and first dust-free gas; the second heat exchange device is used for condensing gaseous ferric chloride in the first dust-free gas into solid ferric chloride and outputting a first gas-solid mixture; the second dust removing equipment is used for carrying out gas-solid separation treatment on the first gas-solid mixture and outputting second powder and second dust-free gas; the third heat exchange device is used for condensing gaseous aluminum chloride in the second dust-free gas into solid aluminum chloride and outputting a second gas-solid mixture; the third dust removing device is used for carrying out gas-solid separation treatment on the second gas-solid mixture and outputting third powder and third dust-free gas; the fourth heat exchange device is used for condensing gaseous silicon chloride in the third dust-free gas into liquid silicon chloride and outputting first condensate and first non-condensable gas; the gas-liquid separation device is used for carrying out gas-liquid separation treatment on the first non-condensable gas and outputting a separation liquid and separation gas; the liquid silicon chloride is enriched in the first condensate and the separating liquid.
As a further improvement of the above-mentioned production system of silicon chloride: the first heat exchange equipment is a waste heat boiler; the second heat exchange equipment and the third heat exchange equipment adopt a baffling cooler with an ash bin, a part of solid particles generated when dust-free gas moves in a baffling way flow into corresponding dust removal equipment along with the gas-solid mixture, and the other part falls into the ash bin; the fourth heat exchange equipment adopts water cooling equipment; at least a first dust removing device in the first dust removing device, the second dust removing device and the third dust removing device adopts a metal filter element.
As a further improvement of the above-mentioned production system of silicon chloride: the third heat exchange device is used for condensing the gaseous silicon chloride in the second non-condensable gas into liquid silicon chloride and outputting the first condensate and the first non-condensable gas.
As a further improvement of the above-mentioned production system of silicon chloride: and a separated gas reflux mechanism for refluxing the separated gas to the chlorination metallurgical furnace.
As a further improvement of the above-mentioned production system of silicon chloride: the method also comprises rectifying equipment for rectifying the first condensate and the separating liquid to purify the liquid silicon chloride.
As a further improvement of the above-mentioned production system of silicon chloride: the first condensate and the first noncondensable gas are jointly stored in the first storage tank, a liquid outlet is formed in the lower portion of the first storage tank, an air outlet is formed in the upper portion of the first storage tank, the air outlet is connected with the gas-liquid separation equipment, and a separation liquid outlet of the gas-liquid separation equipment is connected with the first storage tank or connected with the rectification equipment through a pipeline connected in parallel with the liquid outlet.
As a further improvement of the above-mentioned production system of silicon chloride: further comprises: sublimation equipment for performing sublimation treatment on the third powder to purify aluminum chloride; and the pressurizing equipment is used for pressurizing the third dust-free gas to 0.08-1.2 MPa.
As a further improvement of the above-mentioned production system of silicon chloride: the device comprises a first dust removing device, a second dust removing device, a third dust removing device, a nitrogen conveying mechanism, a gas flow pipeline and a gas flow pipeline, wherein the first dust removing device, the second dust removing device and the third dust removing device are respectively connected with the first dust removing device, the second dust removing device and the third dust removing device; the nitrogen conveying mechanism comprises a nitrogen buffer tank and heating equipment.
As a further improvement of the above-mentioned production system of silicon chloride: the system also comprises a silica powder pulverizing system connected with the chlorination metallurgical furnace and used for pulverizing raw ore into fine silica powder.
As a further improvement of the above-mentioned production system of silicon chloride: the system also comprises a micro silicon powder collecting system which is connected with the chlorination metallurgical furnace and is used for collecting the flue gas generated when preparing industrial silicon or ferrosilicon by the carbothermic method.
In the fourth aspect, the following description is provided: the preparation of the silicon chloride by the micro silicon powder can maximally improve the utilization value of the micro silicon powder, remarkably improve the utilization rate of silicon resources and remarkably reduce the pollution of the micro silicon powder. The gaseous ferric chloride and the gaseous aluminum chloride in the flue gas are also recycled step by step with higher purity, so that the comprehensive utilization effect of the flue gas is obviously improved. The method can directly prepare the silicon chloride with higher purity by using the silica powder and/or the micro silicon powder, and solar grade polysilicon can be obtained by using the silicon chloride as a raw material, and the process route is obviously shortened and simplified compared with the combined route of a carbothermic method and a Siemens method/a silane method/a metallurgical method, thereby being beneficial to improving the production efficiency of the polysilicon.
The utility model is further described below with reference to the drawings and detailed description. Additional aspects and advantages of the utility model will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the utility model.
Drawings
The accompanying drawings, which form a part hereof, are shown by way of illustration and not of limitation, and in which are shown by way of illustration and description of the utility model.
In the drawings:
fig. 1 is a schematic structural view of an embodiment of the silica powder pulverizing system of the present utility model.
FIG. 2 is a schematic structural view of an embodiment of the microsilica collection system of the present utility model.
Fig. 3 is a schematic structural view of a first embodiment of the production system of silicon chloride according to the present utility model.
Fig. 4 is a schematic structural view of a second embodiment of the production system of silicon chloride according to the present utility model.
Fig. 5 is a schematic structural view of a third embodiment of the production system of silicon chloride according to the present utility model.
Fig. 6 is a schematic diagram of a structure of an embodiment of a system for producing polycrystalline silicon according to the present utility model.
The relevant marks in the drawings are as follows:
110-first crushing plant, 120-second crushing plant, 130-third crushing plant, 140-drying plant, 150-sorting plant, 160-collecting plant, 170-first dust bin, 180-first chimney, 190-vibratory feeder, 210-first heat exchange plant, 220-filtering plant, 230-encryption plant, 240-denitration plant, 250-second heat exchange plant, 261-dry desulfurization tower, 262-dust catcher, 270-second dust bin, 280-smelting furnace, 290-second chimney, 300-chlorinated metallurgical furnace, 411-first heat exchange plant, 412-first dust catcher, 413-first ash storage tank, 421-second heat exchange equipment, 422-second dust removal equipment, 423-second ash storage tank, 431-third heat exchange equipment, 432-third dust removal equipment, 433-third ash storage tank, 434-sublimation equipment, 450-fifth heat exchange equipment, 453-second storage tank, 460-pressurizing equipment, 441-fourth heat exchange equipment, 442-gas-liquid separation equipment, 443-first storage tank, 471-nitrogen buffer tank, 472-heating equipment, 480-first fan, 490-rectification equipment, 510-reduction furnace, 520-electrolysis equipment, 530-zinc simple substance storage tank, 540-second fan, 550-mixing equipment, 560-silicon chloride storage tank, 570-melting equipment.
Detailed Description
The present utility model will now be described more fully hereinafter with reference to the accompanying drawings. Those of ordinary skill in the art will be able to implement the utility model based on these descriptions. Before describing the present utility model with reference to the accompanying drawings, it should be noted in particular that:
the technical solutions and technical features provided in the sections including the following description in the present utility model may be combined with each other without conflict.
In addition, the embodiments of the present utility model referred to in the following description are typically only some, but not all, embodiments of the present utility model. Therefore, all other embodiments, which can be made by one of ordinary skill in the art without undue burden, are intended to be within the scope of the present utility model, based on the embodiments of the present utility model.
Terms and units in relation to the present utility model. The terms "comprising," "having," and any variations thereof in the description and claims of the utility model and in the relevant sections are intended to cover a non-exclusive inclusion.
Fig. 1 is a schematic structural view of an embodiment of the silica powder pulverizing system of the present utility model.
As shown in fig. 1, the silica powder pulverizing system includes a first crushing apparatus 110, a second crushing apparatus 120, a third crushing apparatus 130, a drying apparatus 140, a sorting apparatus 150, and a collecting apparatus 160. The first crushing device 110 is used for crushing raw ore into first powder with the granularity less than or equal to 100mm, and the first crushing device 110 is preferably a jaw crusher. The second crushing device 120 is used for crushing the first powder into second powder with the particle size less than or equal to 50mm, and the second crushing device 120 is preferably a hammer crusher or a impact crusher. The third crushing device 130 is used for crushing the second powder into third powder with the particle size less than or equal to 5mm, and the third crushing device 130 is preferably a ball mill. The drying apparatus 140 is used for drying the third powder, and the drying apparatus 140 preferably employs a blower that inputs hot air into the third crushing apparatus 130. The separation device 150 is used for separating fine silica powder with the granularity less than or equal to 1mm from the third powder, outputting coarse silica powder and dust-containing gas carrying the fine silica powder, and the separation device 150 is preferably any one of a three-separation powder separator, a centrifugal powder separator and a cyclone powder separator. The collecting device 160 is used for collecting fine silicon powder in dust-containing gas, and the collecting device 160 is preferably an explosion-proof bag type dust collector.
The raw ore is fed into the first crushing plant 110 by a vibratory feeder 190.
The second powder is transferred to the third crushing apparatus 130 by a dump truck, a loader, a hopper, a speed-regulated feeding belt conveyor, and a bucket elevator.
The fine silicon powder is stored in a first powder bin 170.
The coarse silicon powder is re-fed into the third crushing plant 130 via a pipeline.
The gas discharged from the gas outlet of the collecting device 160 is discharged through the first chimney 180 under the traction of the induced draft fan.
FIG. 2 is a schematic structural view of an embodiment of the microsilica collection system of the present utility model.
As shown in fig. 2, the micro silicon powder collecting system is used for collecting micro silicon powder in flue gas generated when industrial silicon or ferrosilicon is prepared by a carbothermic method, and the micro silicon powder collecting system comprises a first heat exchange device 210, a filtering device 220, an encryption device 230, a denitration device 240, a second heat exchange device 250 and a desulfurization device. The first heatThe heat exchange device 210 is used for reducing the temperature of the flue gas to 260-400 ℃ and outputting first gas, the first heat exchange device 210 is connected with a smoke exhaust pipe of the smelting furnace 280, the first heat exchange device 210 preferably adopts a waste heat boiler, and naturally settled dust in the first heat exchange device 210 is discharged into the encryption device 230. The filtering device 220 is used for collecting the silica fume in the first gas and outputting the second gas and the dust, and the filtering device 220 adopts a metal filter element. The encryption device 230 is configured to encrypt the dust naturally settled in the first heat exchange device 210 and the dust intercepted by the filtering device 220 and output silica fume, and the encryption device 230 encrypts the silica fume to a density of 0.5-0.7 t/m 3 Is provided. The denitration device 240 is configured to perform denitration treatment on the second gas and output a third gas. The second heat exchange device 250 is used for reducing the temperature of the third gas to 160-200 ℃ and outputting the fourth gas, and the second heat exchange device 250 is preferably a waste heat boiler. The desulfurization device is used for desulfurizing the fourth gas and outputting exhaust gas.
The filtering device 220 and the denitration device 240 adopt a filtering and denitration integrated device, and an ash bucket, a filter element and a denitration catalyst filler layer in the device are distributed in the shell from bottom to top. An ammonia spraying mechanism is arranged on an air inlet pipeline of the filtering and denitration integrated device or between the filter element and the denitration catalyst filler, wherein the ammonia spraying mechanism is preferably arranged on the air inlet pipeline, so that ammonia water and first gas can be mixed more uniformly, and the denitration effect is remarkably improved.
The desulfurization device comprises a dry desulfurization tower 261 and a dust remover 262 which are connected in sequence; or the desulfurization apparatus includes a spray tower.
The gas discharged from the gas outlet of the desulfurization apparatus is discharged through the second chimney 290 under the traction of the induced draft fan.
The encrypted microsilica is stored in a second bin 270.
Fig. 3 is a schematic structural view of a first embodiment of the production system of silicon chloride according to the present utility model.
As shown in fig. 3, the production system of silicon chloride includes a chlorinated metallurgical furnace 300, a first heat exchange device 411, a first dust removal device 412, a second heat exchange device 421, a second dust removal device 422, a third heat exchange device 431, a third dust removal device 432, a pressurizing device 460, a fourth heat exchange device 441, and a nitrogen gas conveying mechanism. The chlorination metallurgical furnace 300 is used for reacting a silicon raw material, a carbon simple substance and chlorine gas to generate flue gas containing dust, gaseous ferric chloride, gaseous aluminum chloride and gaseous silicon chloride, wherein the silicon raw material is silica powder and/or micro silica powder. The first heat exchange device 411 is used for performing heat exchange treatment on the flue gas. The first dust removing device 412 is configured to remove dust in the flue gas and output a first powder and a first dust-free gas. The second heat exchange device 421 is configured to condense gaseous ferric chloride in the first dust-free gas into solid ferric chloride and output a first gas-solid mixture. The second dust removing device 422 is configured to perform a gas-solid separation process on the first gas-solid mixture and output a second powder and a second dust-free gas. The third heat exchange device 431 is used for condensing gaseous aluminum chloride in the second dust-free gas into solid aluminum chloride and outputting a second gas-solid mixture. The third dust removing device 432 is configured to perform a gas-solid separation process on the second gas-solid mixture and output a third powder and a third dust-free gas. The pressurizing device 460 is used for pressurizing the third dust-free gas to 0.08-1.2 MPa and then inputting the third dust-free gas into the fourth heat exchange device 441. The fourth heat exchange device 441 is configured to condense gaseous silicon chloride in the third dust-free gas into liquid silicon chloride, and output a first condensate and a first non-condensable gas, where the liquid silicon chloride is enriched in the first condensate. The nitrogen gas delivery mechanism is used for delivering nitrogen gas for back blowing ash removal to the first dust removing device 412, the second dust removing device 422 and the third dust removing device 432, for delivering nitrogen gas for balance ash discharging to the first dust removing device 412, the second dust removing device 422 and the third dust removing device 432 and for delivering nitrogen gas for replacement (used when the vehicle is started and stopped) into the gas flow pipeline, and comprises a nitrogen buffer tank 471 and a heating device 472.
The first heat exchanging device 411 is preferably a waste heat boiler.
The second heat exchange device 421 and the third heat exchange device 431 adopt a baffling cooler with an ash bin, and a part of solid particles generated by dust-free gas during baffling movement flow into corresponding dust removing devices along with the gas-solid mixture, and a part of the solid particles naturally subsides and falls into the ash bin.
The fourth heat exchange device 441 is preferably a water cooling device.
At least the first dust removing device 412 of the first dust removing device 412, the second dust removing device 422 and the third dust removing device 432 adopts a metal filter element.
The powder naturally settled in the heat exchange equipment and the powder intercepted in the corresponding dust removing equipment are stored in the ash storage tank in a concentrated manner, namely the production system also comprises a first ash storage tank 413, a second ash storage tank 423 and a third ash storage tank 433 for respectively storing the first powder, the second powder and the third powder.
The first heat exchange device 411, the first dust removal device 412, the second heat exchange device 421, the second dust removal device 422, the third heat exchange device 431, the third dust removal device 432 and the fourth heat exchange device 441 form a separation and purification mechanism of flue gas, and ferric chloride, aluminum chloride and silicon chloride with higher purity can be recovered step by step.
In order to uniformly disperse the silicon raw material in the chlorination metallurgical furnace 300, the silicon raw material is preferably fed into the chlorination metallurgical furnace 300 in the form of a jet by a Roots blower.
Preferably, the silicon chloride production system further includes a gas-liquid separation device 442 and a separated gas reflux mechanism. The gas-liquid separation device 442 is configured to perform gas-liquid separation processing on the first non-condensable gas and output a separation liquid and a separation gas; the liquid silicon chloride is enriched in the first condensate and the separating liquid. The separated gas recirculation mechanism is for recirculating the separated gas into the chlorinated metallurgical furnace 300, and includes a first blower 480. Therefore, the silicon chloride in the first noncondensable gas can be efficiently recovered, and the maximum utilization of silicon resources is realized.
Fig. 4 is a schematic structural view of a second embodiment of the production system of silicon chloride according to the present utility model.
As shown in fig. 4, on the basis of the first embodiment, the production system of silicon chloride of the present embodiment further includes a fifth heat exchange device 450, where the fifth heat exchange device 450 is configured to condense gaseous titanium chloride in the third dust-free gas and output a second condensate, and a second non-condensable gas, where the second condensate is mainly titanium chloride and is stored in the second tank 453. The fourth heat exchange device 441 is configured to condense gaseous silicon chloride in the second non-condensable gas into liquid silicon chloride and output a first condensate and the first non-condensable gas. Thus, when the silicon raw material contains titanium oxide, by providing the fifth heat exchange device 450 before the fourth heat exchange device 441, gaseous titanium chloride and gaseous silicon chloride in the flue gas can be condensed step by step, thereby further improving the purity of the silicon chloride in the first condensate and the separation liquid. At this time, the separation and purification mechanism further includes a fifth heat exchange device 450 capable of recovering ferric chloride, aluminum chloride, titanium chloride and silicon chloride having higher purity step by step.
Preferably, the production system of silicon chloride further includes a sublimation device 434 for performing sublimation treatment on the third powder to purify aluminum chloride. Therefore, when a small amount of gaseous titanium chloride in the flue gas is condensed together with the gaseous aluminum chloride in advance due to temperature fluctuation and the like, the purity of the aluminum chloride can be improved and the aluminum chloride and the titanium chloride can be separated through sublimation treatment of the third powder. Of course, the purity of ferric chloride can be improved by sublimating the second powder.
Fig. 5 is a schematic structural view of a third embodiment of the production system of silicon chloride according to the present utility model.
As shown in fig. 5, the production system of silicon chloride of the present embodiment further includes a rectifying apparatus 490 for rectifying the first condensate and the separated liquid to purify the liquid silicon chloride, on the basis of the first embodiment or the second embodiment. The first condensate and the first non-condensable gas are stored together in the first storage tank 443, a liquid outlet is arranged below the first storage tank 443, an air outlet is arranged above the first storage tank 443, the air outlet is connected with the gas-liquid separation device 442, and a separation liquid outlet of the gas-liquid separation device 442 is connected with the first storage tank 443 or a separation liquid outlet of the gas-liquid separation device 442 is connected with the rectification device 490 through a pipeline connected in parallel with the liquid outlet. Thus, regardless of whether the gaseous titanium chloride and the gaseous silicon chloride are condensed stepwise or synchronously, the purity of the resulting silicon chloride can be ensured by the rectifying device 490. But when fractional condensation is employed, the efficiency of the rectification will be improved. Of course, the purity of the titanium chloride can also be improved by rectifying the second condensate.
Generally, raw ore contains a large amount of titanium dioxide, and the titanium dioxide contained in the fine silica powder is small after the treatment in the carbothermic smelting furnace 280, so that when the raw ore or the silica powder obtained by crushing the raw ore is contained in the silicon raw material, it is preferable to condense the gaseous titanium chloride and the gaseous silicon chloride stepwise, and when the raw ore is only the fine silica powder, it is preferable to condense the gaseous titanium chloride and the gaseous silicon chloride simultaneously, and then separate the titanium chloride and the silicon chloride by the rectification treatment.
In the three embodiments of the above-described silicon chloride production system, it is preferable, but not limited to, to obtain fine silicon powder and/or micro silicon powder as the silicon raw material using the system shown in fig. 1 and/or fig. 2. For example, the silica fume may be collected by an existing system (e.g., desulfurization followed by low temperature denitration).
Fig. 6 is a schematic diagram of a structure of an embodiment of a system for producing polycrystalline silicon according to the present utility model.
As shown in fig. 6, the production system of polycrystalline silicon includes a production system of silicon chloride, a reduction furnace 510, an electrolysis apparatus 520, a chlorine gas reflux mechanism, and a zinc simple substance reflux mechanism. The production system of silicon chloride is used for producing a raw material containing liquid silicon chloride, and can be, but not limited to, the production system of silicon chloride according to any one of the three embodiments, namely, the raw material can be any one of a first condensate, a mixture of the first condensate and a separating liquid, and liquid silicon chloride produced by rectification. The reduction furnace 510 is used for reacting a liquid zinc simple substance with liquid silicon chloride to generate polysilicon and zinc chloride, and a crystal bed for bearing crystal seeds is arranged in the reduction furnace 510. The electrolysis device 520 is used for carrying out electrolysis treatment on zinc chloride and outputting chlorine and liquid zinc simple substance. The chlorine gas recirculation mechanism is for recirculating chlorine gas into the silicon chloride production system, and includes a second fan 540. The zinc simple substance reflux mechanism is used for refluxing liquid zinc simple substance to the electrolysis equipment 520, and comprises a zinc simple substance storage tank 530, a pump for drawing the liquid zinc simple substance to flow and a heat exchange structure for carrying out heat preservation or heating on the zinc simple substance storage tank 530.
Preferably, a silicon chloride storage tank 560 storing liquid silicon chloride and a pump for drawing the flow of liquid silicon chloride are also included. When the rectifying apparatus 490 is employed, it is preferable to provide the silicon chloride tank 560 and the pump between the first tank 443 and the reduction furnace 510. When the rectifying apparatus 490 is not employed, the first tank 443 may be directly used as the silicon chloride tank 560.
Preferably, the device further comprises a mixing device 550 and a melting device 570, wherein the liquid silicon chloride and the liquid zinc simple substance are mixed in the mixing device 550 and then are input into the reduction furnace 510, and the melting device 570 is used for melting the solid zinc raw material into the liquid zinc simple substance and then is input into the zinc simple substance storage tank 530.
A first embodiment of the method for producing polycrystalline silicon of the present utility model comprises the steps of:
reacting a silicon raw material, a carbon simple substance and chlorine gas to generate flue gas containing dust, gaseous ferric chloride, gaseous aluminum chloride and gaseous silicon chloride, wherein the silicon raw material is silica powder and/or micro silicon powder, and the carbon simple substance is preferably but not limited to semi-coke;
carrying out heat exchange treatment on the flue gas;
removing dust in the flue gas, and outputting first powder and first dust-free gas; the temperature of the first dust-free gas is 350-600 ℃, preferably 420-600 ℃, and most preferably 480-550 ℃; the first powder is mainly unreacted dust and the like, and can be used as mixed sand of a building or re-input into the chlorination metallurgical furnace 300 for reaction;
Condensing gaseous ferric chloride in the first dust-free gas into solid ferric chloride, and outputting a first gas-solid mixture, wherein the temperature of the first gas-solid mixture is 230-300 ℃, preferably 250-280 ℃;
carrying out gas-solid separation treatment on the first gas-solid mixture, and outputting second powder and second dust-free gas; the second powder is mainly solidified ferric chloride;
condensing gaseous aluminum chloride in the second dust-free gas into solid aluminum chloride, and outputting a second gas-solid mixture;
carrying out gas-solid separation treatment on the second gas-solid mixture, and outputting third powder and third dust-free gas; the third powder is mainly solidified aluminum chloride;
pressurizing the third dust-free gas to 0.08-1.2 MPa, preferably 0.1MPa;
condensing gaseous silicon chloride in the third dust-free gas into liquid silicon chloride, and outputting a first condensate and a first non-condensable gas, wherein the temperature of the first non-condensable gas is 0-30 ℃, preferably 10-25 ℃ and most preferably 15-20 ℃;
carrying out gas-liquid separation treatment on the first non-condensable gas, and outputting a separation liquid and separation gas; the liquid silicon chloride is enriched in the separating liquid and the first condensate;
reflux the separation gas to react with the silicon raw material and the carbon simple substance; the mixture of carbon dioxide and carbon monoxide in the separated gas is input into the chlorination metallurgical furnace 300 again for reaction, so that heat can be supplied for the chlorination reaction combustion;
Liquid zinc simple substance is adopted to reduce liquid silicon chloride into polysilicon and zinc chloride.
When the silicon raw material is only micro silicon powder, the carbon simple substance and chlorine react at 1000-2000 ℃ to generate the flue gas. Correspondingly, the temperature of the second gas-solid mixture is 100-165 ℃, and in order to ensure the purity of the second powder, the temperature of the second gas-solid mixture is preferably 140-165 ℃, or the second powder is preferably sublimated. At this time, the purity of the polysilicon prepared by reduction of the liquid silicon chloride in the obtained first condensate and the separating liquid is reached, and of course, the first condensate and the separating liquid can be further subjected to rectification treatment to purify the liquid silicon chloride.
When the silicon raw material is only silica powder, the carbon simple substance and chlorine react at 1723-2230 ℃ to generate the flue gas; when the silicon raw material is silica powder or a mixture of the silica powder and the silica fume, the silica powder, the silica fume, the carbon simple substance and chlorine react at 1723-2000 ℃ to generate the flue gas.
Because the titanium dioxide contained in the silica powder is converted into titanium chloride and continuously exists in the third dust-free gas in a gaseous form, when the gaseous silicon chloride and the gaseous titanium chloride in the third dust-free gas are synchronously condensed, the gaseous silicon chloride and the gaseous titanium chloride are synchronously condensed in the first condensate, and the first condensate and the separating liquid are subjected to rectification treatment to obtain liquid silicon chloride and liquid titanium chloride respectively. At this time, the temperature of the second gas-solid mixture is 120-165 ℃, and then the second powder is sublimated to improve the purity of aluminum chloride, or the temperature of the second gas-solid mixture is 140-165 ℃.
When the gaseous silicon chloride and the gaseous titanium chloride in the third dust-free gas are condensed step by step, firstly, the gaseous titanium chloride in the third dust-free gas is condensed, a second condensate and a second non-condensable gas are output, then the gaseous silicon chloride in the second non-condensable gas is condensed into liquid silicon chloride, and the first condensate and the first non-condensable gas are output. At this time, the temperature of the second gas-solid mixture is 140-165 ℃, and the temperature of the second non-condensable gas is 70-120 ℃. Sublimation treatment and rectification treatment may be employed to ensure purity.
The silica powder is obtained by pulverizing raw ore silica through a system shown in figure 1, and the granularity of the silica powder is less than or equal to 1mm, preferably 200-500 mu m; the micro silicon powder is collected by a system shown in fig. 2 to prepare flue gas generated when industrial silicon or ferrosilicon is prepared by a carbothermic method, and the density of the micro silicon powder is 0.5-0.7 t/m 3 Preferably 0.6t/m 3 。
A second embodiment of the method for producing polycrystalline silicon of the present utility model further comprises, on the basis of the first embodiment, the steps of:
carrying out electrolytic treatment on zinc chloride, and outputting chlorine and liquid zinc simple substance;
reflux chlorine to react with silicon material and carbon simple substance;
and refluxing the liquid zinc simple substance to react with the silicon chloride.
Therefore, the chlorine and the zinc simple substance can be recycled, the cost of investment required by recycling is low, and the raw material consumption is obviously reduced, so that the production cost is obviously reduced.
In summary, according to the utility model, through the efficient combination of the chlorination reaction of the silicon raw material, the reduction reaction of the silicon chloride and the electrolysis reaction of the zinc chloride, the solar-grade polycrystalline silicon with wide application range is obtained, so that the silicon resource is efficiently and deeply utilized, more valuable metals with higher purity are recovered, and compared with the traditional polycrystalline silicon preparation system and process (combination of carbothermic method and Siemens method/silane method/metallurgical method), the method has the advantages of low raw material input cost, low equipment input and energy consumption, short production period, environmental protection and profound economic value.
The content of the present utility model is described above. Those of ordinary skill in the art will be able to implement the utility model based on these descriptions. Based on the foregoing, all other embodiments that may be obtained by one of ordinary skill in the art without undue burden are within the scope of the present utility model.
Claims (9)
1. Silica powder pulverizing system, its characterized in that: comprising the following steps:
a first crushing device (110) for crushing raw ore silica into a first powder having a particle size of 100mm or less;
the second crushing equipment (120) is used for crushing the first powder into second powder with the granularity less than or equal to 50 mm;
a third crushing device (130) for crushing the second powder into a third powder having a particle size of 5mm or less;
drying means (140) for drying the third powder;
the separation equipment (150) is used for separating fine silicon powder with the granularity less than or equal to 1mm from the third powder, and outputting coarse silicon powder and dust-containing gas carrying the fine silicon powder;
a collection device (160) for collecting fine silicon powder in the dust-containing gas;
the first crushing equipment (110), the second crushing equipment (120), the third crushing equipment (130), the sorting equipment (150) and the collecting equipment (160) are sequentially connected, and the drying equipment (140) adopts a blower for inputting hot air into the third crushing equipment (130).
2. The silica powder pulverizing system of claim 1, wherein: the first crushing plant (110) employs a jaw crusher.
3. The silica powder pulverizing system of claim 1, wherein: the second crushing device (120) adopts a hammer crusher or a impact crusher.
4. The silica powder pulverizing system of claim 1, wherein: the third crushing device (130) adopts a ball mill.
5. The silica powder pulverizing system of claim 1, wherein: the collecting device (160) adopts an explosion-proof bag type dust collector.
6. The silica powder pulverizing system of claim 1, wherein: further comprising a vibratory feeder (190) for conveying raw ore to the first crushing plant (110).
7. The silica powder pulverizing system of claim 1, wherein: the device also comprises a dump truck, a loader, a bucket, a speed-regulating feeding belt conveyor and a bucket elevator which are used for conveying the second powder to the third crushing equipment (130).
8. The silica powder pulverizing system of claim 1, wherein: a first bin (170) for storing fine silicon powder; further comprising a conduit for re-feeding the coarse silicon powder to a third crushing plant (130); the device also comprises a draught fan and a first chimney (180), wherein the draught fan is used for discharging traction gas and is sequentially connected with the gas outlet of the collecting device (160).
9. A silica treatment system characterized by: a chlorination metallurgical furnace (300) comprising a treatment of silica and/or microsilica, chlorine and elemental carbon, said chlorination metallurgical furnace (300) being connected to the fine silicon powder output of a silica powder milling system according to any one of claims 1 to 8.
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| CN202320375897.0U CN220166329U (en) | 2023-03-03 | 2023-03-03 | Silica powder pulverizing system and silica treatment system |
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| CN202320375897.0U CN220166329U (en) | 2023-03-03 | 2023-03-03 | Silica powder pulverizing system and silica treatment system |
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