CN203498094U

CN203498094U - Equipment for preparing polycrystalline silicon

Info

Publication number: CN203498094U
Application number: CN201320520589.9U
Authority: CN
Inventors: 万烨; 张升学; 严大洲; 毋克力; 肖荣辉; 汤传斌; 杨永亮
Original assignee: China ENFI Engineering Corp
Current assignee: China ENFI Engineering Corp
Priority date: 2013-08-23
Filing date: 2013-08-23
Publication date: 2014-03-26
Anticipated expiration: 2023-08-23

Abstract

The utility model discloses equipment for preparing polycrystalline silicon. The equipment comprises a hydrochlorinated synthetic reaction device, a first rectifying and purifying device, a disproportionated reaction device, a second rectifying and purifying device and a pyrolytic reaction device, wherein the first rectifying and purifying device is connected with the hydrochlorinated synthetic reaction device; the disproportionated reaction device is connected with the first rectifying and purifying device; the second rectifying and purifying device is connected with the disproportionated reaction device; and the pyrolytic reaction device is connected with the second rectifying and purifying device. The equipment disclosed by the utility model has the advantages that the electronic-grade polycrystalline silicon can be effectively prepared and obtained; the process is simple, safe, energy-saving, environment-friendly and low in cost; and the purity of produced polycrystalline silicon is high, the generated tail gas and waste residue can meet the environment-friendly requirement, and the process is a clean production process for the electronic-grade polycrystalline silicon.

Description

The equipment of preparing polysilicon

Technical field

The utility model relates to photovoltaic industry technical field, particularly, relates to the equipment of preparing polysilicon.

Background technology

Sun power has been subject to global attention as a kind of renewable and clean energy resource, utilizes the technology that solar energy resources generates electricity to be considered to the most promising new energy technology in the current whole world.Thereby the photovoltaic industry that the solar energy generation technology of take is core has obtained swift and violent development at the beginning of 21 century.Polysilicon is as the main raw material(s) of photovoltaic industry, and along with the fast development of photovoltaic industry, its demand significantly increases.

Yet, present stage preparation technology and the equipment of polysilicon still have much room for improvement.

Utility model content

The following discovery of the utility model based on utility model people completes:

The production of polysilicon technique of having reported is at present more, mainly contains the production technique such as improved Siemens, silane thermal decomposition process, metallurgy method.Wherein, improved Siemens production of polysilicon technique is the main flow technique of producing at present polysilicon, and global 80% left and right all adopts this technique.This technique be take trichlorosilane as main raw material, under the high temperature action of 1000-1100 ℃, in CVD reduction furnace with hydrogen generation reduction reaction, the high purity polycrystalline silicon generating is deposited on silicon wicking surface, output rod-like polycrystal silicon, the required minimum reduction power consumption of this explained hereafter polysilicon is 40KWh/kgSi, and production cost is 15 dollars/kgSi.Yet along with the expansion of polysilicon production capacity, industry competition is fierce, polysilicon price-slashing, the production cost decline limited space of improved Siemens.Silane thermal decomposition process production of polysilicon technique developed comparatively fast in recent years, it mainly comes from the new silane thermal decomposition process of U.S. UCC company, the method has advantages of that a lot of improved Siemens are incomparable,, little power consumption lower such as thermal decomposition of silane temperature, silane are easily purified, product purity is high, raw material consumption is low etc., is a kind of promising novel process.Yet in new silane thermal decomposition process production technique, trichlorosilane two step disproportionations produce silane gas, disproportionation efficiency is lower, and generation intermediate product dichloro-dihydro silicon needs further to purify separated, and separating difficulty is larger.Thereby, seek a kind of cost electronic-grade polycrystalline silicon production method low, that consume energy few imperative.

The utility model is intended at least solve one of technical problem existing in prior art.For this reason, an object of the present utility model is to propose a kind of equipment of producing electronic-grade polycrystalline silicon for the preparation of low-cost energy-saving type.

According to an aspect of the present utility model, the utility model proposes a kind of equipment for the preparation of polysilicon.According to embodiment of the present utility model, this equipment comprises: for making silica flour, hydrogen and being selected from hydrogenchloride and at least one generation chlorine hydrogenation building-up reactions of silicon tetrachloride, to obtain the chlorine hydrogenation synthetic reaction device of the chlorine hydrogenation building-up reactions product that comprises trichlorosilane; For the described chlorine hydrogenation building-up reactions product that comprises trichlorosilane is carried out to the first rectifying purification process, to obtain the first rectifying purification devices of trichlorosilane and the first distillation residual liquid, described the first rectifying purification devices is connected with described chlorine hydrogenation synthetic reaction device; Be used for making described trichlorosilane generation disproportionation reaction, to obtain the disproportionation reaction device of the disproportionation reaction product that comprises silicon tetrachloride and silane, described disproportionation reaction device is connected with described the first rectifying purification devices; For described disproportionation reaction product is carried out to the second rectifying purification process, to obtain the second rectifying purification devices of silane gas and silicon tetrachloride, described the second rectifying purification devices is connected with described disproportionation reaction device; And for making described silane gas generation pyrolytic reaction, to obtain the pyrolytic reaction device of polysilicon, described pyrolytic reaction device is connected with described the second rectifying purification devices.

Utility model people is surprised to find, utilize this equipment can effectively prepare electronic-grade polycrystalline silicon, and the technique that this equipment relates to is simple, safety, energy-conserving and environment-protective, cost are low, and the polysilicon purity of producing is high, the tail gas producing and waste residue can meet the requirement of environmental protections, are electronic-grade polycrystalline silicon process for cleanly preparing.

In addition, according to the equipment for the preparation of polysilicon of the utility model above-described embodiment, can also there is following additional technical characterictic:

According to embodiment of the present utility model, described the second rectifying purification devices is connected with described chlorine hydrogenation synthesizer, so as by the silicon tetrachloride obtaining in described the second rectifying purification devices for described chlorine hydrogenation building-up reactions.Thus, the silicon tetrachloride in the second rectifying purification devices product has been carried out to recycle, thereby can realize energy-conserving and environment-protective, the object reducing costs.

According to embodiment of the present utility model, further comprise: for silicon tetrachloride liquid is mixed with hydrogen, obtain the Liqiud-gas mixing device of gas-liquid mixture; Be used for utilizing described chlorine hydrogenation building-up reactions product to carry out heat exchange process to described gas-liquid mixture, to obtain through the gas-liquid mixture of preheating with through the heat exchanger of overcooled chlorine hydrogenation building-up reactions product, described heat exchanger is connected with described chlorine hydrogenation synthetic reaction device with described Liqiud-gas mixing device respectively; And heat for the gas-liquid mixture to through preheating, to obtain the gaseous mixture that comprises silicon tetrachloride and hydrogen, and the described gaseous mixture that comprises silicon tetrachloride and hydrogen being supplied to the resistance heater of described chlorine hydrogenation synthetic reaction device, described resistance heater is connected with described chlorine hydrogenation synthetic reaction device with described heat exchanger respectively.Thus, can in the situation that power consumption be minimum, realize the cooling of chlorine hydrogenation building-up reactions product simultaneously and gas-liquid mixture is carried out to preheating, and can effectively obtain the gaseous mixture that comprises silicon tetrachloride and hydrogen, for chlorine hydrogenation building-up reactions in follow-up circulation is supplied raw materials, thereby can effectively realize energy-conserving and environment-protective, the object reducing costs.

According to embodiment of the present utility model, further comprise: for by the described cleaning apparatus that carries out dust removal process through overcooled chlorine hydrogenation building-up reactions product, described cleaning apparatus is connected with described heat exchanger; And for the chlorine hydrogenation building-up reactions product through dust removal process is carried out to condensation, so that difference recover hydrogen and chlorosilane liquid produced, and described chlorosilane liquid produced is supplied to described the first rectifying purification devices for the first condensing works of described the first rectifying purification process, described the first condensing works is connected with the first rectifying purification devices with described cleaning apparatus respectively.Thus, after overcooled chlorine hydrogenation building-up reactions product is by above-mentioned processing, can obtain chlorosilane liquid produced and hydrogen, and chlorosilane liquid produced and hydrogen can be supplied to respectively the related device of equipment of the present utility model, carry out recycle again, thereby can effectively realize energy-conserving and environment-protective, the object reducing costs.

According to embodiment of the present utility model, described the first condensing works is connected with described chlorine hydrogenation synthetic reaction device, for described hydrogen being supplied to described chlorine hydrogenation synthetic reaction device.Thus, hydrogen can be recycled, for the chlorine hydrogenation building-up reactions of carrying out in chlorine hydrogenation synthetic reaction device is supplied raw materials, energy-conserving and environment-protective, and can reduce production costs.

According to embodiment of the present utility model, described the first rectifying purification devices comprises a plurality of rectifying tower of series connection, and wherein, each rectifying tower all arranges respectively opening for feed and discharge port from bottom to top along the axial direction due of described rectifying tower.Thus, can effectively improve the efficiency of rectifying purification process in the first rectifying purification devices, be conducive to the carrying out of subsequent step.

According to embodiment of the present utility model, described the first rectifying purification devices comprises the first rectifying tower, Second distillation column and the 3rd rectifying tower of series connection.Thus, can guarantee suitable production cost and higher rectifying purification efficiency simultaneously, be conducive to the carrying out of subsequent step.

According to embodiment of the present utility model, described disproportionation reaction device is disproportionation reactor, described disproportionation reactor further comprises: disproportionation reactor body, limits disproportionation reaction space in described disproportionation reactor body, and be provided with catalyst layer in described disproportionation reaction space; For supply with the trichlorosilane opening for feed of trichlorosilane to described disproportionation reaction space, described trichlorosilane opening for feed is arranged on the below of described catalyst layer; And for the formed disproportionation reaction product that comprises silicon tetrachloride and silane being discharged to the disproportionation reaction product discharge port of described disproportionation reactor, described disproportionation reaction product discharge port is arranged on the top of described catalyst layer.Thus, disproportionation reaction efficiency is high, effective, and production safety, power consumption less, cost is low, the carrying out that be conducive to subsequent step.

According to embodiment of the present utility model, described the second rectifying purification devices is low-temperature fractionating tower.Thus, production safety, and power consumption less, production cost is low, rectifying purification efficiency is high, effective, is conducive to the carrying out of subsequent step.

According to embodiment of the present utility model, further comprise for before pyrolytic reaction, in advance the silane gas storing with liquid form is carried out to the vaporization process device of vaporization process, described vaporization process device is connected with described pyrolytic reaction device with described the second rectifying purification devices respectively.Thus, be conducive to the carrying out of pyrolytic reaction in pyrolytic reaction device, thereby can effectively prepare polysilicon, and cost is low, needing can be few, energy-conserving and environment-protective, and pyrolytic reaction efficiency is high.

According to embodiment of the present utility model, described pyrolytic reaction device is reduction furnace, is provided with silicon core as the carrier of crystal deposition in described reduction furnace.Thus, pyrolytic reaction efficiency is high, effective, and the electronic-grade polycrystalline silicon purity preparing is high.

According to embodiment of the present utility model, described reduction furnace is bell-jar reduction furnace.Thus, pyrolytic reaction efficiency is high, effective.

According to embodiment of the present utility model, in described reduction furnace, be provided with 12,24 or 36 pairs of silicon rods.Thus, adopt silicon core as carrier.Further, according to embodiment of the present utility model, in reduction furnace, be also provided with the cooling jacket consistent with silicon core logarithm.Thereby, be conducive to silane gas checking solution deposition, prepare high-purity electronic-grade polycrystalline silicon.

According to embodiment of the present utility model, further comprise: for described the first distillation residual liquid is carried out to flash distillation processing, to obtain the flash distillation treatment unit of silicon tetrachloride gas and solid residue, described flash distillation treatment unit is connected with described the first rectifying purification devices; For described silicon tetrachloride gas is carried out to condensation process, so that acquisition silicon tetrachloride liquid, and described silicon tetrachloride liquid is supplied to described Liqiud-gas mixing device for the second condensing works of described chlorine hydrogenation building-up reactions, described the second condensing works is connected with described Liqiud-gas mixing device with described flash distillation treatment unit respectively; And the residue treatment device of processing for described solid residue being carried out successively to alkali lye hydrolysis neutralizing treatment and press filtration, described residue treatment device is connected with described flash distillation treatment unit.Thus, can effectively realize the cycling and reutilization of the first distillation residual liquid, thereby reach energy-conserving and environment-protective, the object reducing costs.

According to embodiment of the present utility model, further comprise: for the reduction tail gas of pyrolytic reaction being compressed to the first compression set that pressure is 6.0～10.0MPa, described the first compression set is connected with described pyrolytic reaction device; And for being-100～-120 degrees Celsius by the reduction tail gas condensing through overdraft to temperature, to silane gas is condensed into silane liquid and obtains hydrogen, and by described silane liquid supply to described vaporization process device, described hydrogen is supplied to described Liqiud-gas mixing device for the 3rd condensing works of described chlorine hydrogenation building-up reactions, and described the 3rd condensing works is connected with described the first compression set, described Liqiud-gas mixing device and described vaporization process device respectively.Thus, can effectively to the reduction tail gas producing in pyrolytic reaction device, process, realize non-pollution discharge, guarantee cleaner production, and realize the cycling and reutilization of reduction tail gas, thereby reach energy-conserving and environment-protective, the object reducing costs.

According to embodiment of the present utility model, further comprise: for what each device was produced, contain chlorosilane but containing the tail gas of silane, be not compressed to the second compression set that pressure is 0.25～0.50MPa; For by through overdraft to contain chlorosilane but containing the tail gas of silane, be not cooled to temperature be-15～-30 degrees Celsius, to obtain chlorosilane liquid produced and residual gas, and described chlorosilane liquid produced is supplied to described the first rectifying purification devices for the 4th condensing works of described the first rectifying purification process, described the 4th condensing works is connected with described the first rectifying purification devices with described the second compression set respectively; For described residual gas is carried out to drip washing, to obtain through the gas of drip washing and the elution device of washing water, described elution device is connected with described the 4th condensing works; And for utilizing alkali lye to neutralize described washing water, and carry out press filtration to neutralizing rear liquid, so that in obtaining and the washing water treatment unit of water and filter residue, described washing water treatment unit is connected with described elution device.Thus, can effectively to what produce in each device, contain chlorosilane but containing the tail gas of silane, not process, realize non-pollution discharge, guarantee cleaner production, and realize the cycling and reutilization of tail gas, thereby reach energy-conserving and environment-protective, the object reducing costs.

According to embodiment of the present utility model, further comprise for by described and water supply to described elution device, to described residual gas is carried out to the transport pipe of drip washing.Thus, can by and water carry out recycle, thereby reduce production costs, and realize non-pollution discharge, guarantee cleaner production.

It should be noted that, with respect to prior art, the equipment for the preparation of polysilicon of the present utility model has the following advantages:

1, the equipment for the preparation of polysilicon of the present utility model, the whole process system safety and stability relating to, technique is simple, can realize;

2, the equipment for the preparation of polysilicon of the present utility model can be silane gas by trichlorosilane one stage disproportionation;

3, in the product producing for the preparation of the equipment of polysilicon of the present utility model, silane gas and chlorosilane are easily separated, and after purifying, purity is high, more than can reaching 9N;

4, in the equipment for the preparation of polysilicon of the present utility model, the silane gas cracking temperature of acquisition is lower, and energy consumption is lower, and then the cost of production polysilicon is lower;

5, utilizing polysilicon prepared by equipment of the present utility model is electronic-grade polycrystalline silicon, and purity is high, can reach 9N-11N;

6, the tail gas of equipment exhausting of the present utility model and waste residue all meet environmental requirement, are polysilicon cleaner production equipment.

Additional aspect of the present utility model and advantage in the following description part provide, and part will become obviously from the following description, or recognize by practice of the present utility model.

Accompanying drawing explanation

Above-mentioned and/or additional aspect of the present utility model and advantage accompanying drawing below combination obviously and is easily understood becoming the description of embodiment, wherein:

Fig. 1 has shown according to embodiment of the utility model, for the preparation of the schematic flow sheet of the applicable method of the equipment of polysilicon;

Fig. 2 has shown according to embodiment of the utility model, for the preparation of the schematic flow sheet of the applicable method of the equipment of polysilicon;

Fig. 3 has shown according to the structural representation of the equipment for the preparation of polysilicon of an embodiment of the utility model;

Fig. 4-Figure 11 has shown respectively the local structure schematic diagram according to the equipment for the preparation of polysilicon of an embodiment of the utility model.

Embodiment

Describe embodiment of the present utility model below in detail, the example of described embodiment is shown in the drawings, and wherein same or similar label represents same or similar element or has the element of identical or similar functions from start to finish.Below by the embodiment being described with reference to the drawings, be exemplary, only for explaining the utility model, and can not be interpreted as restriction of the present utility model.

In description of the present utility model, term " axially ", " on ", orientation or the position relationship of the indication such as D score, " top ", " end " be based on orientation shown in the drawings or position relationship, it is only the utility model rather than require the utility model with specific orientation structure and operation, therefore can not be interpreted as restriction of the present utility model for convenience of description.

In the utility model, the terms such as unless otherwise clearly defined and limited, term " is connected ", " connection ", " fixing " should be interpreted broadly, and for example, can be to be fixedly connected with, and can be also to removably connect, or connect integratedly; Can be mechanical connection, can be to be also electrically connected to; Can be to be directly connected, also can indirectly be connected by intermediary, can be the connection of two element internals.For the ordinary skill in the art, can understand as the case may be the concrete meaning of above-mentioned term in the utility model.

In the utility model, unless otherwise clearly defined and limited, First Characteristic Second Characteristic it " on " or D score can comprise that the first and second features directly contact, also can comprise that the first and second features are not directly contacts but contact by the other feature between them.And, First Characteristic Second Characteristic " on ", " top " and " above " comprise First Characteristic directly over Second Characteristic and oblique upper, or only represent that First Characteristic level height is higher than Second Characteristic.First Characteristic Second Characteristic " under ", " below " and " below " comprise First Characteristic under Second Characteristic and tiltedly, or only represent that First Characteristic level height is less than Second Characteristic.

It should be noted that, term " first ", " second " be only for describing object, and can not be interpreted as indication or hint relative importance or the implicit quantity that indicates indicated technical characterictic.Thus, one or more these features can be expressed or impliedly be comprised to the feature that is limited with " first ", " second ".

According to an aspect of the present utility model, the utility model proposes a kind of equipment for the preparation of polysilicon.According to embodiment of the present utility model, with reference to Fig. 3, the equipment for the preparation of polysilicon of the present utility model comprises: chlorine hydrogenation synthetic reaction device 1, the first rectifying purification devices 2, disproportionation reaction device 3, the second rectifying purification devices 4 and pyrolytic reaction device 5.

According to some embodiment of the utility model, described chlorine hydrogenation synthetic reaction device 1 is for making silica flour, hydrogen and being selected from hydrogenchloride and at least one generation chlorine hydrogenation building-up reactions of silicon tetrachloride, to obtain the chlorine hydrogenation building-up reactions product that comprises trichlorosilane; Described the first rectifying purification devices 2 is connected with described chlorine hydrogenation synthetic reaction device 1, for the described chlorine hydrogenation building-up reactions product that comprises trichlorosilane is carried out to the first rectifying purification process, to obtain trichlorosilane and the first distillation residual liquid; Described disproportionation reaction device 3 is connected with described the first rectifying purification devices 2, for making described trichlorosilane generation disproportionation reaction, to obtain the disproportionation reaction product that comprises silicon tetrachloride and silane; Described the second rectifying purification devices 4 is connected with described disproportionation reaction device 3, for described disproportionation reaction product is carried out to the second rectifying purification process, to obtain silane gas and silicon tetrachloride; Described pyrolytic reaction device 5 is connected with described the second rectifying purification devices 4, for making described silane gas generation pyrolytic reaction, to obtain polysilicon.Utility model people is surprised to find, utilize this equipment can effectively prepare electronic-grade polycrystalline silicon, and the technique that this equipment relates to is simple, safety, energy-conserving and environment-protective, cost are low, and the polysilicon purity of producing is high, the tail gas producing and waste residue can meet the requirement of environmental protections, are electronic-grade polycrystalline silicon process for cleanly preparing.

In order to make those skilled in the art more easily understand the method for polysilicon and the applicable equipment thereof prepared of the present utility model, below in conjunction with Fig. 3-Figure 11, the Whole Equipment for the preparation of polysilicon of the present utility model and local structure and function thereof are described in detail.

Wherein, it should be noted that, each accompanying drawing and herein described " STC " refer to silicon tetrachloride, and " TCS " refers to trichlorosilane.

According to embodiment of the present utility model, in the chlorine hydrogenation synthetic reaction device 1 shown in Fig. 3, the condition of chlorine hydrogenation building-up reactions is not particularly limited.According to concrete examples more of the present utility model, in chlorine hydrogenation synthetic reaction device 1, be provided with nickel-base catalyst or copper-based catalysts, so that when there is nickel-base catalyst or copper-based catalysts, the gaseous mixture that comprises silicon tetrachloride and hydrogen is contacted with silica flour, described chlorine hydrogenation building-up reactions occurs.Wherein, the chemical reaction relating generally to is:

3SiCl ₄+2H ₂+Si——4SiHCl ₃。Thus, can effectively improve the efficiency of chlorine hydrogenation building-up reactions, be conducive to subsequent step and carry out.Wherein, in the gaseous mixture that comprises silicon tetrachloride and hydrogen, the ratio of silicon tetrachloride and hydrogen is not particularly limited.According to embodiment of the present utility model, described in comprise silicon tetrachloride and hydrogen gaseous mixture in, the mol ratio of silicon tetrachloride and hydrogen is 1:2～5.Thus, the efficiency of chlorine hydrogenation building-up reactions significantly improves, and is conducive to subsequent step and carries out.

According to embodiment of the present utility model, the temperature and pressure that carries out chlorine hydrogenation building-up reactions in chlorine hydrogenation synthetic reaction device 1 is not particularly limited, as long as can effectively react, obtains the chlorine hydrogenation building-up reactions product that comprises trichlorosilane.According to embodiment more of the present utility model, described chlorine hydrogenation building-up reactions is to carry out at the temperature of 500～550 degrees Celsius.According to other embodiment of the present utility model, described chlorine hydrogenation building-up reactions is at 500～550 degrees Celsius, under the condition of 1.5～3.5MPa, carries out.Thus, the efficiency of chlorine hydrogenation building-up reactions is high, is conducive to subsequent step and carries out.

In addition, the source of the silicon tetrachloride adopting in chlorine hydrogenation synthetic reaction device 1 is not particularly limited, and can directly provide, also can be from the reaction product of subsequent step or waste liquid separated acquisition.According to embodiment of the present utility model, at least a portion of described silicon tetrachloride derives from described disproportionation reaction device 3.Thus, the silicon tetrachloride being about in disproportionation reaction product has carried out recycle, thereby can realize energy-conserving and environment-protective, the object reducing costs.

According to embodiment of the present utility model, described the second rectifying purification devices 4 (not shown) that is connected with described chlorine hydrogenation synthesizer 1 so that by the silicon tetrachloride obtaining in described the second rectifying purification devices for described chlorine hydrogenation building-up reactions.Thus, the silicon tetrachloride producing in the second rectifying purification devices can be carried out to recycle, thereby can realize energy-conserving and environment-protective, the object reducing costs.

According to embodiment of the present utility model, with reference to Fig. 4, the equipment for the preparation of polysilicon of the present utility model may further include: Liqiud-gas mixing device 6, heat exchanger 7 and resistance heater 8.According to embodiment of the present utility model, described Liqiud-gas mixing device 6, for silicon tetrachloride liquid is mixed with hydrogen, obtains gas-liquid mixture; Described heat exchanger 7 is connected with described chlorine hydrogenation synthetic reaction device 1 with described Liqiud-gas mixing device 6 respectively, be used for utilizing described chlorine hydrogenation building-up reactions product to carry out heat exchange process to described gas-liquid mixture, to obtain through the gas-liquid mixture of preheating with through overcooled chlorine hydrogenation building-up reactions product; Described resistance heater 8 is connected with described chlorine hydrogenation synthetic reaction device 1 with described heat exchanger 7 respectively, for the gas-liquid mixture to through preheating, heat, so that the gaseous mixture that comprises silicon tetrachloride and hydrogen described in obtaining, and the described gaseous mixture that comprises silicon tetrachloride and hydrogen is supplied to described chlorine hydrogenation synthetic reaction device 1.Thus, can in the situation that power consumption be minimum, realize the cooling of chlorine hydrogenation building-up reactions product simultaneously and gas-liquid mixture is carried out to preheating, and can effectively obtain the gaseous mixture that comprises silicon tetrachloride and hydrogen, for chlorine hydrogenation building-up reactions in follow-up circulation is supplied raw materials, thereby can effectively realize energy-conserving and environment-protective, the object reducing costs.

According to embodiment of the present utility model, with reference to Fig. 4, the equipment for the preparation of polysilicon of the present utility model may further include: cleaning apparatus 9 and the first condensing works 10.According to embodiment of the present utility model, cleaning apparatus 9 is connected with heat exchanger 7, to carry out dust removal process by described through overcooled chlorine hydrogenation building-up reactions product; The first condensing works 10 is connected with the first rectifying purification devices 2 with cleaning apparatus 9 respectively, for the chlorine hydrogenation building-up reactions product through dust removal process is carried out to condensation, so that difference recover hydrogen and chlorosilane liquid produced, described chlorosilane liquid produced comprises trichlorosilane and silicon tetrachloride, and described chlorosilane liquid produced is supplied to described the first rectifying purification devices 2 for described the first rectifying purification process.Thus, after overcooled chlorine hydrogenation building-up reactions product is by above-mentioned processing, can obtain chlorosilane liquid produced and hydrogen, and chlorosilane liquid produced and hydrogen can be supplied to respectively the related device of equipment of the present utility model, carry out recycle again, thereby can effectively realize energy-conserving and environment-protective, the object reducing costs.

According to embodiment of the present utility model, described the first condensing works 10 is connected with described chlorine hydrogenation synthetic reaction device 1, for described hydrogen being supplied to described chlorine hydrogenation synthetic reaction device 1.Thus, hydrogen can be recycled, for the chlorine hydrogenation building-up reactions of carrying out in chlorine hydrogenation synthetic reaction device is supplied raw materials, energy-conserving and environment-protective, and can reduce production costs.

According to embodiment of the present utility model, described the first rectifying purification devices 2 comprises a plurality of rectifying tower of series connection, and wherein, each rectifying tower all arranges respectively opening for feed and discharge port from bottom to top along the axial direction due of described rectifying tower.Thus, can be used in the material that carries out rectification process and be along the axial direction due of each rectifying tower and move from bottom to top, thereby can effectively improve the efficiency of rectifying purification process in the first rectifying purification devices, be conducive to the carrying out of subsequent step.

According to concrete examples more of the present utility model, with reference to Fig. 5, the first rectifying purification devices 2 comprises the first rectifying tower 21, Second distillation column 22 and the 3rd rectifying tower 23 of series connection.Thus, can guarantee suitable production cost and higher rectifying purification efficiency simultaneously, be conducive to the carrying out of subsequent step.Wherein, the condition of carrying out the first rectifying purification process in the first rectifying purification devices 2 is that the reaction conditions in each rectifying tower is not particularly limited, as long as can obtain trichlorosilane by effective purifying from the chlorine hydrogenation building-up reactions product that comprises trichlorosilane.According to embodiment of the present utility model, the rectification temperature of described the first rectifying tower 21 is 60～100 degrees Celsius, and pressure is 0.2MPa, and reflux ratio is 10～50:1; The rectification temperature of described Second distillation column 22 is 100～140 degrees Celsius, and pressure is 0.5MPa, and reflux ratio is 20～50:1; The rectification temperature of described the 3rd rectifying tower 23 is 60～80 degrees Celsius, and pressure is 0.2MPa, and reflux ratio is 20～50:1.Thus, can guarantee safety in production, and power consumption less, production cost is low, rectifying purification efficiency is high, effective, is conducive to the carrying out of subsequent step.

Wherein, the chemical reaction relating in disproportionation reaction device 3 is mainly: 4SiHCl ₃---SiH ₄+ 3SiCl ₄.And according to embodiment of the present utility model, the condition of carrying out disproportionation reaction in disproportionation reaction device 3 is not particularly limited, as long as the disproportionation reaction of trichlorosilane can be carried out safely, effectively obtain disproportionation reaction product.According to concrete examples more of the present utility model, in described disproportionation reaction device 3, described disproportionation reaction is at 50～80 degrees Celsius, under the condition of 0.2～0.6MPa, carries out.Thus, production safety, and power consumption less, production cost is low, disproportionation reaction efficiency is high, effective, is conducive to the carrying out of subsequent step.

According to embodiment of the present utility model, disproportionation reaction device 3 is disproportionation reactor, and with reference to Fig. 6, described disproportionation reactor further comprises: disproportionation reactor body 31, trichlorosilane opening for feed 34 and disproportionation reaction product discharge port 35.Wherein, according to embodiment of the present utility model, in described disproportionation reactor body 31, limit disproportionation reaction space 32, and be provided with catalyst layer 33 in described disproportionation reaction space 32; Described trichlorosilane opening for feed 34 is arranged on the below of described catalyst layer 33, for supplying with trichlorosilane to described disproportionation reaction space 32; Described disproportionation reaction product discharge port 35 is arranged on the top of described catalyst layer 33, for the formed disproportionation reaction product that comprises silicon tetrachloride and silane is discharged to described disproportionation reactor.Thus, disproportionation reaction efficiency is high, effective, and production safety, power consumption less, cost is low, the carrying out that be conducive to subsequent step.

According to embodiment of the present utility model, the type of the second rectifying purification devices 4 and the condition of wherein processing are not particularly limited.According to concrete examples more of the present utility model, with reference to Fig. 7, described the second rectifying purification devices 4 is low-temperature fractionating tower, and wherein, the temperature in described low-temperature fractionating tower is-60～-80 degrees Celsius, and pressure is 0.6～1.0MPa, and reflux ratio is 5～20:1.Thus, production safety, and power consumption less, production cost is low, rectifying purification efficiency is high, effective, is conducive to the carrying out of subsequent step.

According to embodiment of the present utility model, with reference to Fig. 8, equipment for the preparation of polysilicon of the present utility model may further include vaporization process device 11, described vaporization process device 11 is connected with described pyrolytic reaction device 5 with described the second rectifying purification devices 4 respectively, for before pyrolytic reaction, in advance the silane gas storing with liquid form is carried out to vaporization process.Thus, be conducive to the carrying out of pyrolytic reaction in pyrolytic reaction device, thereby can effectively prepare polysilicon, and cost is low, needing can be few, energy-conserving and environment-protective, and pyrolytic reaction efficiency is high.

According to embodiment of the present utility model, the type of pyrolytic reaction device is not particularly limited.According to concrete examples more of the present utility model, described pyrolytic reaction device 5 is reduction furnace, is provided with silicon core as the carrier of crystal deposition in described reduction furnace.Thus, pyrolytic reaction efficiency is high, effective, and the electronic-grade polycrystalline silicon purity preparing is high.According to other embodiment of the present utility model, with reference to Fig. 8, described reduction furnace is bell-jar reduction furnace.Thus, pyrolytic reaction efficiency is high, effective.In addition, in reduction furnace, the quantity of silicon rod and the temperature in reduction furnace, pressure condition are also not particularly limited, as long as be conducive to pyrolytic reaction.According to embodiment of the present utility model, in described reduction furnace, be provided with 12,24 or 36 pairs of silicon rods.Thus, can adopt silicon core as carrier.Further, according to embodiment of the present utility model, in reduction furnace, be also provided with the cooling jacket consistent with silicon core logarithm.Thereby, be conducive to silane gas checking solution deposition, prepare high-purity electronic-grade polycrystalline silicon.According to other embodiment of the present utility model, the temperature in described reduction furnace is 750～900 degrees Celsius, and pressure is 0.15～0.30MPa.Thus, pyrolytic reaction efficiency is high, effective, and reaction safety, and the electronic-grade polycrystalline silicon purity preparing is high.

According to embodiment of the present utility model, with reference to Fig. 9, the equipment for the preparation of polysilicon of the present utility model can further include: flash distillation treatment unit 12, the second condensing works 13 and residue treatment device 14.According to embodiment of the present utility model, as shown in Figure 9, described flash distillation treatment unit 12 is connected with described the first rectifying purification devices 2, for described the first distillation residual liquid is carried out to flash distillation processing, to obtain silicon tetrachloride gas and solid residue; Described the second condensing works 13 is connected with described Liqiud-gas mixing device 6 with described flash distillation treatment unit 12 respectively, for described silicon tetrachloride gas is carried out to condensation process, so that acquisition silicon tetrachloride liquid, and described silicon tetrachloride liquid is supplied to described Liqiud-gas mixing device 6, for described chlorine hydrogenation building-up reactions; Described residue treatment device 14 is connected with described flash distillation treatment unit 12, for described solid residue being carried out successively to alkali lye hydrolysis neutralizing treatment and press filtration, processes.Thus, can effectively realize the cycling and reutilization of the first distillation residual liquid, thereby reach energy-conserving and environment-protective, the object reducing costs.Wherein, it should be noted that, when the first rectifying purification devices 2 as shown in Figure 5, during for first rectifying tower, Second distillation column of series connection and the 3rd rectifying tower, the first distillation residual liquid is the raffinate that discharge Second distillation column bottom.

According to embodiment of the present utility model, with reference to Figure 10, equipment for the preparation of polysilicon of the present utility model may further include: the first compression set 15 and the 3rd condensing works 16, according to embodiment of the present utility model, described the first compression set 15 is connected with described pyrolytic reaction device 5, for the reduction tail gas of pyrolytic reaction is compressed to pressure, is 6.0～10.0MPa; Described the 3rd condensing works 16 is connected with described the first compression set 15, described Liqiud-gas mixing device 6 and described vaporization process device 11, being used for is-100～-120 degrees Celsius by the reduction tail gas condensing through overdraft to temperature, to silane gas is condensed into silane liquid and obtains hydrogen, and by described silane liquid supply to described vaporization process device 11, described hydrogen is supplied to described Liqiud-gas mixing device 6, for described chlorine hydrogenation building-up reactions.Thus, can effectively to the reduction tail gas producing in pyrolytic reaction device, process, realize non-pollution discharge, guarantee cleaner production, and realize the cycling and reutilization of reduction tail gas, thereby reach energy-conserving and environment-protective, the object reducing costs.

According to embodiment of the present utility model, with reference to Figure 11, the equipment for the preparation of polysilicon of the present utility model can further include: the second compression set 17, the 4th condensing works 18, elution device 19 and washing water treatment unit (not shown).Wherein, according to embodiment of the present utility model, described the second compression set 17 is 0.25～0.50MPa for each device is produced contain chlorosilane but be not compressed to pressure containing the tail gas of silane; Described the 4th condensing works 18 is connected with described the first rectifying purification devices 2 with described the second compression set 17 respectively, for by through overdraft to contain chlorosilane but containing the tail gas of silane, be not cooled to temperature be-15～-30 degrees Celsius, to obtain chlorosilane liquid produced and residual gas, and described chlorosilane liquid produced be supplied to described the first rectifying purification devices 2 for described the first rectifying purification process; Described elution device 19 is connected with described the 4th condensing works 18, for described residual gas is carried out to drip washing, to obtain gas and the washing water through drip washing; Described washing water treatment unit is connected with described elution device 19, for utilizing alkali lye to neutralize described washing water, and carries out press filtration to neutralizing rear liquid, so that in obtaining and water and filter residue.Thus, can effectively to what produce in each device, contain chlorosilane but containing the tail gas of silane, not process, realize non-pollution discharge, guarantee cleaner production, and realize the cycling and reutilization of tail gas, thereby reach energy-conserving and environment-protective, the object reducing costs.

According to embodiment of the present utility model, can also by pipeline by described and water supply to described elution device 19, for described residual gas is carried out to drip washing.Thus, can by and water carry out recycle, thereby reduce production costs, and realize non-pollution discharge, guarantee cleaner production.

Above part has been described the equipment for the preparation of polysilicon of the present utility model in detail, in order to understand better this equipment, below the applicable method of this equipment is described in detail again.

Thereby according to another aspect of the present utility model, the utility model has also proposed a kind of method of preparing polysilicon.According to embodiment of the present utility model, see figures.1.and.2, the method comprises the following steps:

S100: chlorine hydrogenation building-up reactions

First, make silica flour, hydrogen and be selected from hydrogenchloride and at least one generation chlorine hydrogenation building-up reactions of silicon tetrachloride, to obtain the chlorine hydrogenation building-up reactions product that comprises trichlorosilane.Wherein, the chemical reaction that this step relates generally to is:

3SiCl ₄+2H ₂+Si——4SiHCl ₃。

According to embodiment of the present utility model, the condition of chlorine hydrogenation building-up reactions is not particularly limited.According to concrete examples more of the present utility model, can when there is nickel-base catalyst or copper-based catalysts, the gaseous mixture that comprises silicon tetrachloride and hydrogen be contacted with silica flour, to there is described chlorine hydrogenation building-up reactions.Thus, can effectively improve the efficiency of chlorine hydrogenation building-up reactions, be conducive to subsequent step and carry out.Wherein, in the gaseous mixture that comprises silicon tetrachloride and hydrogen, the ratio of silicon tetrachloride and hydrogen is not particularly limited.According to embodiment of the present utility model, described in comprise silicon tetrachloride and hydrogen gaseous mixture in, the mol ratio of silicon tetrachloride and hydrogen is 1:2～5.Thus, the efficiency of chlorine hydrogenation building-up reactions significantly improves, and is conducive to subsequent step and carries out.

According to embodiment of the present utility model, the preparation method of the gaseous mixture that comprises silicon tetrachloride and hydrogen is not particularly limited.According to embodiment more of the present utility model, this gaseous mixture that comprises silicon tetrachloride and hydrogen can obtain through the following steps: silicon tetrachloride liquid is mixed with hydrogen, obtain gas-liquid mixture; Utilize described chlorine hydrogenation building-up reactions product to carry out heat exchange process to described gas-liquid mixture, to obtain through the gas-liquid mixture of preheating with through overcooled chlorine hydrogenation building-up reactions product; And utilize resistance heater, the gas-liquid mixture through preheating is heated, so that the gaseous mixture that comprises silicon tetrachloride and hydrogen described in obtaining.Thus, can in the situation that power consumption be minimum, realize the cooling of chlorine hydrogenation building-up reactions product simultaneously and gas-liquid mixture is carried out to preheating, and can effectively obtain the gaseous mixture that comprises silicon tetrachloride and hydrogen, for the chlorine hydrogenation building-up reactions in follow-up circulation is supplied raw materials, thereby can effectively realize energy-conserving and environment-protective, the object reducing costs.

In addition, for through overcooled chlorine hydrogenation building-up reactions product, can also be further processed.According to embodiment of the present utility model, above-mentioned method of the present utility model may further include: by described, through overcooled chlorine hydrogenation building-up reactions product, carry out dust removal process; Chlorine hydrogenation building-up reactions product through dust removal process is carried out to condensation, so that difference recover hydrogen and chlorosilane liquid produced, described chlorosilane liquid produced comprises trichlorosilane and silicon tetrachloride; And described chlorosilane liquid produced is used for to described the first rectifying purification process.Thus, after overcooled chlorine hydrogenation building-up reactions product is by above-mentioned processing, can obtain chlorosilane liquid produced and hydrogen, and chlorosilane liquid produced and hydrogen can be supplied to respectively the corresponding steps of method of the present utility model, carry out recycle again, thereby can effectively realize energy-conserving and environment-protective, the object reducing costs.And for reclaiming the hydrogen obtaining, according to embodiment of the present utility model, described hydrogen can be returned for carrying out described chlorine hydrogenation building-up reactions.Thus, hydrogen can be recycled, for chlorine hydrogenation building-up reactions is supplied raw materials, energy-conserving and environment-protective, and can reduce production costs.

According to embodiment of the present utility model, the temperature and pressure of chlorine hydrogenation building-up reactions is not particularly limited, as long as can effectively react, obtains the chlorine hydrogenation building-up reactions product that comprises trichlorosilane.According to embodiment more of the present utility model, described chlorine hydrogenation building-up reactions is to carry out at the temperature of 500～550 degrees Celsius.Thus, the efficiency of chlorine hydrogenation building-up reactions is high, is conducive to subsequent step and carries out.According to embodiment of the present utility model, described chlorine hydrogenation building-up reactions is at 500～550 degrees Celsius, under the condition of 1.5～3.5MPa, carries out.Thus, chlorine hydrogenation building-up reactions safety, efficiency are high, are conducive to subsequent step and carry out.

In addition, the source of the silicon tetrachloride that chlorine hydrogenation building-up reactions adopts is not particularly limited, and can directly provide, also can be from the reaction product of subsequent step or waste liquid separated acquisition.According to embodiment of the present utility model, at least a portion of described silicon tetrachloride obtains by trichlorosilane is carried out to disproportionation reaction.Thus, the silicon tetrachloride being about in the product of follow-up disproportionation reaction has carried out recycle, thereby can realize energy-conserving and environment-protective, the object reducing costs.According to other embodiment of the present utility model, separated acquisition in first distillation residual liquid that comprises silicon tetrachloride that can also produce from follow-up the first rectifying purification step.Thus, can effectively realize the cycling and reutilization of producing waste liquid, thereby reach energy-conserving and environment-protective, the object reducing costs.

S200: the first rectifying purification process

Secondly, the chlorine hydrogenation building-up reactions product that comprises trichlorosilane of above-mentioned acquisition is carried out to the first rectifying purification process, to obtain trichlorosilane and the first distillation residual liquid.

According to embodiment of the present utility model, the device that the first rectifying purification process adopts is not particularly limited, as long as can effectively realize the first rectifying purification process of the chlorine hydrogenation building-up reactions product to comprising trichlorosilane.According to embodiment more of the present utility model, described the first rectifying purification process is to utilize a plurality of rectifying tower of series connection to carry out, and wherein, in each rectifying tower, for carrying out the material of rectification process, is along the axial direction due of described rectifying tower and moves from bottom to top.Thus, can effectively improve the efficiency of rectifying purification process, be conducive to the carrying out of subsequent step.According to preferred embodiments more of the present utility model, described the first rectifying purification process is to utilize the first rectifying tower, Second distillation column and the 3rd rectifying tower of series connection to carry out.Thus, can guarantee suitable production cost and higher rectifying purification efficiency simultaneously, be conducive to the carrying out of subsequent step.Wherein, the condition of the first rectifying purification process is that the reaction conditions in each rectifying tower is not particularly limited, as long as can obtain trichlorosilane by effective purifying from the chlorine hydrogenation building-up reactions product that comprises trichlorosilane.According to embodiment of the present utility model, the rectification temperature of described the first rectifying tower is 60～100 degrees Celsius, and pressure is 0.2MPa, and reflux ratio is 10～50:1; The rectification temperature of described Second distillation column is 100～140 degrees Celsius, and pressure is 0.5MPa, and reflux ratio is 20～50:1; The rectification temperature of described the 3rd rectifying tower is 60～80 degrees Celsius, and pressure is 0.2MPa, and reflux ratio is 20～50:1.Thus, can guarantee safety in production, and power consumption less, production cost is low, rectifying purification efficiency is high, effective, can purify and obtain purity is more than 99% trichlorosilane, is conducive to the carrying out of subsequent step.

The waste liquid that can also produce the first rectifying purification process in addition, i.e. the first distillation residual liquid is further processed.According to embodiment of the present utility model, further comprise: described the first distillation residual liquid is carried out to flash distillation processing, to obtain silicon tetrachloride gas and solid residue; Described silicon tetrachloride gas is carried out to condensation process, to obtain silicon tetrachloride liquid; Described silicon tetrachloride liquid is used for to described chlorine hydrogenation building-up reactions; And described solid residue is carried out to alkali lye hydrolysis neutralizing treatment and press filtration processing successively.Thus, can effectively realize the cycling and reutilization of the first distillation residual liquid, thereby reach energy-conserving and environment-protective, the object reducing costs.Wherein, when the first rectifying purification process is while utilizing the first rectifying tower of series connection recited above, Second distillation column and the 3rd rectifying tower to carry out, the first distillation residual liquid is the raffinate that discharge Second distillation column bottom.

S300: disproportionation reaction

Then, make described trichlorosilane generation disproportionation reaction, to obtain the disproportionation reaction product that comprises silicon tetrachloride and silane.Wherein, the chemical reaction that this step relates generally to is: 4SiHCl ₃---SiH ₄+ 3SiCl ₄.

According to embodiment of the present utility model, the condition of disproportionation reaction is not particularly limited, as long as can carry out safely the disproportionation reaction of trichlorosilane, effectively obtains above-mentioned disproportionation reaction product.According to concrete examples more of the present utility model, described disproportionation reaction is at 50～80 degrees Celsius, under the condition of 0.2～0.6MPa, carries out.Thus, production safety, and power consumption less, production cost is low, disproportionation reaction efficiency is high, effective, is conducive to the carrying out of subsequent step.

In addition, the device that carries out disproportionation reaction is also not particularly limited, as long as can guarantee production safety, efficiently.According to embodiment of the present utility model, described disproportionation reaction is carried out in disproportionation reactor, and described disproportionation reactor may further include: disproportionation reactor body, trichlorosilane opening for feed and disproportionation reaction product discharge port.According to concrete examples more of the present utility model, in above-mentioned disproportionation reactor body, limit disproportionation reaction space, and be provided with catalyst layer in described disproportionation reaction space; Described trichlorosilane opening for feed is arranged on the below of described catalyst layer, for supplying with trichlorosilane to described disproportionation reaction space; Described disproportionation reaction product discharge port is arranged on the top of described catalyst layer, for the formed disproportionation reaction product that comprises silicon tetrachloride and silane is discharged to described disproportionation reactor.Thus, disproportionation reaction efficiency is high, effective, and production safety, power consumption less, cost is low, the carrying out that be conducive to subsequent step.

S400: the second rectifying purification process

Next, described disproportionation reaction product is carried out to the second rectifying purification process, to obtain silane gas and silicon tetrachloride.

According to embodiment of the present utility model, device and the required condition of carrying out the second rectifying purification process are not particularly limited.According to concrete examples more of the present utility model, described the second rectifying purification process is carried out in low-temperature fractionating tower, and wherein, the temperature in described low-temperature fractionating tower is-60～-80 degrees Celsius, and pressure is 0.6～1.0MPa, and reflux ratio is 5～20:1.Thus, can guarantee production safety, and power consumption less, production cost is low, rectifying purification efficiency is high, effective, is conducive to the carrying out of subsequent step.

Wherein, the silicon tetrachloride raffinate for producing in the second rectifying purification step, can be further processed.According to embodiment of the present utility model, silicon tetrachloride raffinate is by processing, and the silicon tetrachloride of acquisition is for described chlorine hydrogenation building-up reactions.Thus, effectively realize the recycle of silicon tetrachloride raffinate, and reduced the dispensing of chlorine hydrogenation building-up reactions raw material, thereby can realize energy-conserving and environment-protective, the object reducing costs.

S500: pyrolytic reaction

Then, make the silane gas of above-mentioned acquisition that pyrolytic reaction occur in reduction furnace, wherein, in described reduction furnace, be provided with silicon core as the carrier of crystal deposition, to obtain polysilicon.Wherein, the chemical reaction that this step relates generally to is: SiH ₄---Si+2H ₂.

According to embodiment of the present utility model, the described silane gas obtaining is stored with liquid form collection, and there is pyrolytic reaction in entering reduction furnace before, in advance the silane of described liquid form is carried out in vaporizer to vaporization process in previous step.Thus, be convenient to the transportation of silane gas, and be conducive to pyrolytic reaction and carry out, and then can effectively prepare polysilicon, and cost is low, need to lack, energy-conserving and environment-protective, and pyrolytic reaction efficiency is high.

According to embodiment of the present utility model, the type of the reduction furnace that pyrolytic reaction can adopt is not particularly limited.According to concrete examples more of the present utility model, described reduction furnace is bell-jar reduction furnace.Thus, pyrolytic reaction efficiency is high, effective, and the electronic-grade polycrystalline silicon purity preparing is high.

In addition, in reduction furnace, the quantity of silicon rod and the temperature in reduction furnace, pressure condition are also not particularly limited, as long as be conducive to pyrolytic reaction.According to embodiment of the present utility model, in described reduction furnace, be provided with 12,24 or 36 pairs of silicon rods.Thus, can adopt silicon core as carrier.Further, according to embodiment of the present utility model, in reduction furnace, be also provided with the cooling jacket consistent with silicon core logarithm.Thereby, be conducive to silane gas checking solution deposition, prepare high-purity electronic-grade polycrystalline silicon.According to other embodiment of the present utility model, the temperature in described reduction furnace is 750～900 degrees Celsius, and pressure is 0.15～0.30MPa.Thus, pyrolytic reaction efficiency is high, effective, and reaction safety, and the electronic-grade polycrystalline silicon purity preparing is high.

Wherein, the reduction tail gas producing can also be further processed in pyrolytic reaction, to carry out recycle, wherein, the method that reduction tail gas is processed is not particularly limited.According to embodiment of the present utility model, may further include: it is 6.0～10.0MPa that the reduction tail gas of pyrolytic reaction is compressed to pressure; By the reduction tail gas condensing through overdraft to temperature, be-100～-120 degrees Celsius, to silane gas is condensed into silane liquid, and obtain hydrogen; And described hydrogen is used for to described chlorine hydrogenation building-up reactions.Thus, can effectively to reduction tail gas, process, realize non-pollution discharge, guarantee cleaner production, and realize the cycling and reutilization of reduction tail gas, thereby reach energy-conserving and environment-protective, the object reducing costs.

In addition, to what produce in each step, contain chlorosilane but containing the tail gas of silane, also can not be further processed, to carry out cycling and reutilization, wherein, the method for processing is not particularly limited.According to embodiment of the present utility model, may further include: by each step, produce to contain chlorosilane but containing the tail gas of silane, be not compressed to pressure be 0.25～0.50MPa, and be further cooled to the temperature of-15～-30 degrees Celsius, to obtain chlorosilane liquid produced and residual gas; Described chlorosilane liquid produced is carried out to described the first rectifying purification process; Described residual gas is carried out to drip washing, to obtain gas and washing water through drip washing; And utilize alkali lye to neutralize described washing water, to neutralizing rear liquid, carry out press filtration, so that in obtaining and water and filter residue.Thus, can effectively to what produce in each step, contain chlorosilane but containing the tail gas of silane, not process, realize non-pollution discharge, guarantee cleaner production, and realize the cycling and reutilization of tail gas, thereby reach energy-conserving and environment-protective, the object reducing costs.Wherein, above-mentioned in and water also can recycle, according to embodiment of the present utility model, will be in described and water be used for described residual gas to carry out drip washing.Thus, can by and water carry out recycle, thereby reduce production costs, and realize non-pollution discharge, guarantee cleaner production.

According to other embodiment of the present utility model, the polysilicon method of preparing of the present utility model can further include: the separated silicon tetrachloride obtaining in intermediate steps is returned to S100(chlorine hydrogenation building-up reactions), make it participate in chlorine hydrogenation building-up reactions, and then enter in the processing step of the method for preparing polysilicon of the present utility model, carry out sequential loop.Thus, can realize the production object of economy, environmental protection.

Utility model people is surprised to find, utilize the polysilicon method of preparing of the present utility model can effectively prepare electronic-grade polycrystalline silicon, and the method technique is simple, safety, energy-conserving and environment-protective, cost are low, and the polysilicon purity of producing is high, the tail gas producing and waste residue can meet the requirement of environmental protections, are electronic-grade polycrystalline silicon process for cleanly preparing.

In addition,, according to embodiment more of the present utility model, with reference to Fig. 2, the polysilicon method of preparing of the present utility model can also comprise the following steps:

(a) chlorine hydrogenation synthesis step: adopting silica flour, hydrogen and supplementary silicon tetrachloride (or hydrogenchloride) is raw material with the silicon tetrachloride that comes from subsequent step (b), (c), control temperature 500～550 degree, pressure 1.5～3.5MPa, silicon tetrachloride and hydrogen proportioning 1:2～1:5, under Ni-based or copper-base catalyst effect, in fixed bed (or fluidized-bed) hydrogenation reactor, by converting silicon tetrachloride, be trichlorosilane, for step (c) provides trichlorosilane raw material.Main reaction is: 3SiCl ₄+ 2H ₂+ Si---4SiHCl ₃.

(b) trichlorosilane rectification and purification step: the chlorosilane mixed solution that comes from step (a) enters in three rectifying tower of series connection, controls 60～100 ℃ of the first rectifying tower temperature, pressure 0.2MPa, reflux ratio 10:1～50:1; Control 100～140 ℃ of Second distillation column temperature, pressure 0.5MPa, reflux ratio 20:1～50:1; Control 60～80 ℃ of the 3rd rectifying tower temperature, pressure 0.2MPa, reflux ratio 20:1～50:1.Obtaining purity is more than 99% trichlorosilane, and silicon tetrachloride returns to step (a).

(c) trichlorosilane disproportionation step: come from the trichlorosilane of step (b), pass in disproportionation reactor, under catalyst action, control 50～80 ℃ of reactor temperatures, pressure 0.2～0.6MPa, makes trichlorosilane be converted into silane gas.Principal reaction equation is: 4SiHCl ₃---SiH ₄+ 3SiCl ₄.

(d) silane gas low temperature fractionation step: come from the silane gas that contains impurity of step (c), enter in low-temperature fractionating tower, temperature-60～-80 ℃ in control tower, pressure 0.60～1.0MPa, reflux ratio 5:1～20:1.Thereby the silane purity of overhead extraction can reach 9N～11N, has mainly removed the impurity compounds such as B, P, Al, C.This part silane gas is with the extraction of liquid mode storage.

(e) silane gas Pintsch process is prepared polysilicon step: the silane gas from step (d) enters in bell-jar reduction furnace, control 750～900 ℃ of internal temperatures, 0.15MPa～0.30MPa, is deposited on silicon core silane gas cracking, and the hydrogen of generation is back to step (a) recycle.Cracking transformation efficiency of silane gas can reach more than 90%.Principal reaction equation is: SiH ₄---Si+2H ₂.

(f) raffinate recycling step: be that the raffinate that discharge Second distillation column bottom is mainly rich in silicon tetrachloride and a small amount of solid residue from the first distillation residual liquid producing in step (b), by it after flash distillation, dedusting and condensation etc. are processed, silicon tetrachloride is reclaimed, and solid residue drains into step (h) and processes.

(g) tail gas recycle step: mainly process two portions tail gas, the tail gas that is rich in chlorosilane that a part is discharged for step (a) and (b), (c), (f), after overdraft deep cooling, to after most of chlorosilane separation, reclaim to step (b), contain on a small quantity the tail gas of chlorosilane after tail gas eluting column hydrolysis treatment is qualified, be disposed in atmosphere, and hydrolysis residue to step (h) is processed; Another part is the reduction tail gas from step (e), this partial tail gas contains hydrogen and silane gas, after overdraft deep cooling, hydrogen is separated and is supplied to step (a) recycle, silane gas be condensed into liquid after overflash to step (e) recycle.

(h) residue neutralization procedure: by the aforementioned solid residue of step (f) and the hydrolysis residue of step (g) of coming from, interpolation neutralizing agent (calcium hydroxide alkali lye) neutralizes, press filtration is processed, then qualified solid slag is carried out to environment protection emission, and waste water is back to the described tail gas eluting column recycle of step (g).

Below by specific embodiment, the utility model is described, it should be noted that these embodiment are only used to illustration purpose, and can not be construed to by any way restriction of the present utility model.In addition, in the following example, if not otherwise specified, the equipment that adopted and material are commercially available.

Embodiment 1

Utilize the equipment for the preparation of polysilicon of the present utility model shown in Fig. 3-Figure 11, the flow process shown in seeing figures.1.and.2, according to following process, prepare polysilicon:

(1) chlorine hydrogenation synthesis step: from the silicon tetrachloride of following step (2), step (3) with hydrogen after gas liquid mixer proportioning is mixed, with the heat exchange of hydrogenation reactor exit gas process, enter resistive heater heats to certain temperature, this mixed gas directly enters in hydrogenation reactor, control temperature 500～550 degree, pressure 1.5～3.5MPa, silicon tetrachloride and hydrogen proportioning 1:2～1:5, under Ni-based or copper-base catalyst effect, react with silica flour.Reacted gas after efficient gas-solid fly-ash separator in gas-gas heat exchanger with from the gas converting heat of gas liquid mixer, reactant gases after cooling enters bubbling gas wash tower, to after the further dedusting of solid dust, enter integrated condenser, chlorosilane condensate enters liquid collection tank, and Hydrogen Separation out enters gas liquid mixer recycle through compressor.

(2) chlorosilane purification step: utilize the difference of trichlorosilane and silicon tetrachloride boiling point, have at the same temperature the principle of different volatility, adopt three towers (being rectifying tower) purify trichlorosilane.Raffinate is discharged from Second distillation column, and the TCS that process is purified is from the 3rd rectifying tower top extraction, and the STC of recovery discharges and is back to the gas liquid mixer step (1) from the 3rd rectifier bottoms.Obtaining purity is more than 99% trichlorosilane.

(3) trichlorosilane disproportionation step: 50～80 ℃ of the temperature of control disproportionation reactor, pressure 0.2～0.6MPa, under catalyst action, passes into the TCS of the 3rd rectifying tower top extraction in reactor, and disproportionation reaction occurs, and produces silane gas.

(4) silane gas low temperature fractionation step: utilize the difference of impurity, chlorosilane and the silane gas boiling points such as B, P, C, have at the same temperature the principle of different volatility, adopt low-temperature fractionating tower purification silane gas.The silane gas that comes from step (3) enters low-temperature fractionating tower, temperature-60～-80 ℃ in control tower, pressure 0.60～1.0MPa, reflux ratio 5:1～20:1.From the silane purity of overhead extraction, can reach 9N-11N, mainly remove the impurity compounds such as B, P, Al, C.From the high purity silane gas of overhead extraction, go step (5), impurity etc. are discharged at the bottom of tower.

(5) silane gas high temperature pyrolysis step: the high purity silane gas from step (4) enters vaporizer, is vaporizated into gas and enters bell-jar reduction furnace, and inside arranges silicon core as the carrier of crystal deposition, can be 12 pairs of rods, 24 pairs of rods or 36 pairs of excellent reduction furnaces.Control 750～900 ℃ of internal temperatures, under 0.15MPa～0.30MPa, silane gas cracking is deposited on silicon core, generates bar-shaped electronic-grade polycrystalline silicon.After the reduction tail gas recycle producing, being back to step (7) processes.Wherein, cracking transformation efficiency of silane gas can reach more than 90%.

(6) raffinate recycling step: the raffinate of discharging from step (2) the 3rd rectifier bottoms, is rich in silicon tetrachloride and a small amount of solid residue, through flash tank evaporation, flash tank is with whipping appts, axle and body adopt mechanical seal, and its outside is steam jacket, adopt steam heating.The silicon tetrachloride gas being evaporated from flash tank enters follow-up water cooler condensation, and silicon tetrachloride liquid is back to gas liquid mixer in step (1).Solid residue through with alkali lye hydrolysis neutralization by press filtration be harmless in and slag discharge.

(7) tail gas recycle step: whole system is divided into two strands of tail gas.The tail gas of tail gas 1 for containing chlorosilane, wherein containing silane gas.This partial tail gas is through compressor compresses to 0.25～0.50MPa, enter deep freezer, control cryogenic temperature-15～-30 ℃, chlorosilane condensate gets off to be back to step (2), the uncooled gas getting off enters tail gas eluting column, and the qualified gas emptying after drip washing, in washing water and alkali lye and rear press filtration, filter residue is arranged outward, and Zhong Heshui returns to eluting column recycle; Tail gas 2 is for being rich in the gas of hydrogen and a small amount of silane gas, from bell-jar reduction furnace reduction tail gas out, this portion gas is through compressor compresses to 6.0～10.0MPa, enter deep freezer and be condensed to-100～-120 ℃, silane gas is condensed into liquid and enters vaporizer, and Hydrogen Separation out enters chlorine hydrogenation synthetic reaction device.

In the description of this specification sheets, the description of reference term " embodiment ", " some embodiment ", " example ", " concrete example " or " some examples " etc. means to be contained at least one embodiment of the present utility model or example in conjunction with specific features, structure, material or the feature of this embodiment or example description.In this manual, the schematic statement of above-mentioned term is not necessarily referred to identical embodiment or example.And the specific features of description, structure, material or feature can be with suitable mode combinations in any one or more embodiment or example.

Although illustrated and described embodiment of the present utility model, those having ordinary skill in the art will appreciate that: in the situation that not departing from principle of the present utility model and aim, can carry out multiple variation, modification, replacement and modification to these embodiment, scope of the present utility model is limited by claim and equivalent thereof.

Claims

1. for the preparation of an equipment for polysilicon, it is characterized in that, comprising:

For making silica flour, hydrogen and being selected from hydrogenchloride and at least one generation chlorine hydrogenation building-up reactions of silicon tetrachloride, to obtain the chlorine hydrogenation synthetic reaction device of chlorine hydrogenation building-up reactions product;

For described chlorine hydrogenation building-up reactions product is carried out to the first rectifying purification process, to obtain the first rectifying purification devices of trichlorosilane and the first distillation residual liquid, described the first rectifying purification devices is connected with described chlorine hydrogenation synthetic reaction device;

Be used for making described trichlorosilane generation disproportionation reaction, to obtain the disproportionation reaction device of disproportionation reaction product, described disproportionation reaction device is connected with described the first rectifying purification devices;

For described disproportionation reaction product is carried out to the second rectifying purification process, to obtain the second rectifying purification devices of silane gas and silicon tetrachloride, described the second rectifying purification devices is connected with described disproportionation reaction device; And

Be used for making described silane gas generation pyrolytic reaction, to obtain the pyrolytic reaction device of polysilicon, described pyrolytic reaction device is connected with described the second rectifying purification devices.

2. equipment according to claim 1, is characterized in that, described the second rectifying purification devices is connected with described chlorine hydrogenation synthesizer, so as by the silicon tetrachloride obtaining in described the second rectifying purification devices for described chlorine hydrogenation building-up reactions.

3. equipment according to claim 1, is characterized in that, further comprises:

For silicon tetrachloride liquid is mixed with hydrogen, obtain the Liqiud-gas mixing device of gas-liquid mixture;

Be used for utilizing described chlorine hydrogenation building-up reactions product to carry out heat exchange process to described gas-liquid mixture, to obtain through the gas-liquid mixture of preheating with through the heat exchanger of overcooled chlorine hydrogenation building-up reactions product, described heat exchanger is connected with described chlorine hydrogenation synthetic reaction device with described Liqiud-gas mixing device respectively; And

For the gas-liquid mixture to through preheating, heat, so that acquisition gaseous mixture, and described gaseous mixture being supplied to the resistance heater of described chlorine hydrogenation synthetic reaction device, described resistance heater is connected with described chlorine hydrogenation synthetic reaction device with described heat exchanger respectively.

4. equipment according to claim 3, is characterized in that, further comprises:

Be used for the described cleaning apparatus that carries out dust removal process through overcooled chlorine hydrogenation building-up reactions product, described cleaning apparatus is connected with described heat exchanger; And

For the chlorine hydrogenation building-up reactions product through dust removal process is carried out to condensation, so that difference recover hydrogen and chlorosilane liquid produced, and described chlorosilane liquid produced is supplied to described the first rectifying purification devices for the first condensing works of described the first rectifying purification process, described the first condensing works is connected with the first rectifying purification devices with described cleaning apparatus respectively.

5. equipment according to claim 4, is characterized in that, described the first condensing works is connected with described chlorine hydrogenation synthetic reaction device, for described hydrogen being supplied to described chlorine hydrogenation synthetic reaction device.

6. equipment according to claim 1, is characterized in that, described the first rectifying purification devices comprises a plurality of rectifying tower of series connection, and wherein, each rectifying tower all arranges respectively opening for feed and discharge port from bottom to top along the axial direction due of described rectifying tower.

7. equipment according to claim 6, is characterized in that, described the first rectifying purification devices comprises the first rectifying tower, Second distillation column and the 3rd rectifying tower of series connection.

8. equipment according to claim 1, is characterized in that, described disproportionation reaction device is disproportionation reactor, and described disproportionation reactor further comprises:

Disproportionation reactor body, limits disproportionation reaction space in described disproportionation reactor body, and is provided with catalyst layer in described disproportionation reaction space;

For supply with the trichlorosilane opening for feed of trichlorosilane to described disproportionation reaction space, described trichlorosilane opening for feed is arranged on the below of described catalyst layer; And

For formed disproportionation reaction product being discharged to the disproportionation reaction product discharge port of described disproportionation reactor, described disproportionation reaction product discharge port is arranged on the top of described catalyst layer.

9. equipment according to claim 1, is characterized in that, described the second rectifying purification devices is low-temperature fractionating tower.

10. equipment according to claim 3, it is characterized in that, further comprise for before pyrolytic reaction, in advance the silane gas storing with liquid form is carried out to the vaporization process device of vaporization process, described vaporization process device is connected with described pyrolytic reaction device with described the second rectifying purification devices respectively.

11. equipment according to claim 1, is characterized in that, described pyrolytic reaction device is reduction furnace, are provided with silicon core as the carrier of crystal deposition in described reduction furnace.

12. equipment according to claim 11, is characterized in that, described reduction furnace is bell-jar reduction furnace.

13. equipment according to claim 12, is characterized in that, are provided with 12,24 or 36 pairs of silicon rods in described reduction furnace.

14. equipment according to claim 3, is characterized in that, further comprise:

For described the first distillation residual liquid is carried out to flash distillation processing, to obtain the flash distillation treatment unit of silicon tetrachloride gas and solid residue, described flash distillation treatment unit is connected with described the first rectifying purification devices;

For described silicon tetrachloride gas is carried out to condensation process, so that acquisition silicon tetrachloride liquid, and described silicon tetrachloride liquid is supplied to described Liqiud-gas mixing device for the second condensing works of described chlorine hydrogenation building-up reactions, described the second condensing works is connected with described Liqiud-gas mixing device with described flash distillation treatment unit respectively; And

The residue treatment device of processing for described solid residue being carried out successively to alkali lye hydrolysis neutralizing treatment and press filtration, described residue treatment device is connected with described flash distillation treatment unit.

15. equipment according to claim 10, is characterized in that, further comprise:

For the reduction tail gas of pyrolytic reaction is compressed to the first compression set that pressure is 6.0～10.0MPa, described the first compression set is connected with described pyrolytic reaction device; And

Being used for is-100～-120 degrees Celsius by the reduction tail gas condensing through overdraft to temperature, to silane gas is condensed into silane liquid and obtains hydrogen, and by described silane liquid supply to described vaporization process device, described hydrogen is supplied to described Liqiud-gas mixing device for the 3rd condensing works of described chlorine hydrogenation building-up reactions, and described the 3rd condensing works is connected with described the first compression set, described Liqiud-gas mixing device and described vaporization process device respectively.

16. equipment according to claim 1, is characterized in that, further comprise:

For the tail gas that each device is produced, be compressed to the second compression set that pressure is 0.25～0.50MPa;

For the tail gas through overdraft is cooled to temperature, it is-15～-30 degrees Celsius, to obtain chlorosilane liquid produced and residual gas, and described chlorosilane liquid produced is supplied to described the first rectifying purification devices for the 4th condensing works of described the first rectifying purification process, described the 4th condensing works is connected with described the first rectifying purification devices with described the second compression set respectively;

For described residual gas is carried out to drip washing, to obtain through the gas of drip washing and the elution device of washing water, described elution device is connected with described the 4th condensing works; And

Be used for utilizing alkali lye to neutralize described washing water, and carry out press filtration to neutralizing rear liquid, so that in obtaining and the washing water treatment unit of water and filter residue, described washing water treatment unit is connected with described elution device.

17. equipment according to claim 16, is characterized in that, further comprise for by described and water supply to described elution device, to described residual gas is carried out to the transport pipe of drip washing.