CN104163534B - Method and system of processing chlorosilane waste liquid - Google Patents
Method and system of processing chlorosilane waste liquid Download PDFInfo
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- CN104163534B CN104163534B CN201410369315.3A CN201410369315A CN104163534B CN 104163534 B CN104163534 B CN 104163534B CN 201410369315 A CN201410369315 A CN 201410369315A CN 104163534 B CN104163534 B CN 104163534B
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Abstract
The invention discloses a method and a system of processing a chlorosilane waste liquid. The chlorosilane waste liquid comprises at least one of trichlorosilane, tetrachlorosilane, a silicon powder, polymers and metal chlorides. The method comprises: (1) performing evaporation processing on the chlorosilane waste liquid, so as to obtain gaseous-state light compositions and a post-evaporation solution, wherein the gaseous-state light compositions comprise trichlorosilane and tetrachlorosilane, and the post-evaporation solution comprises the silicon powder, the polymers and the metal chlorides; (2) performing condensation processing on the gaseous-state light compositions, so as to obtain liquid-state light compositions; (3) performing rectification processing on the liquid-state light compositions, so as to obtain a tower-top gas and tower bottoms, wherein the tower-top gas comprises trichlorosilane, and the tower bottoms comprise tetrachlorosilane; (4) employing the silicon powder and hydrogen to perform cold hydrogenation processing on the tower bottoms, so as to obtain trichlorosilane; and (5) employing limewater to perform neutralization processing on the post-evaporation solution, so as to obtain a residue solution. The method is capable of realizing continuous processing on the chlorosilane waste liquid and effectively avoiding obstruction of pipelines.
Description
Technical field
The invention belongs to technical field of polysilicon production, specifically, the present invention relates to a kind of method processing chlorosilane waste liquid
And system.
Background technology
In production of polysilicon, rectification needs intermittent discharge except discharging continuously at the bottom of weight tower tower bottom waste liquid, cold hydrogenation quencher
Waste liquid, the main component of waste liquid is: trichlorosilane, Silicon chloride., the most a small amount of silica flour, metal chloride, polymer,
Wherein, metal chloride is aluminum chloride and/or calcium chloride, and polymer is polymer and/or the polymerization of boron chloride of Phosphorous chloride.
Thing, these chlorosilane waste liquids are poisonous and harmful liquid and easily block system pipeline, the equipment with severe corrosive, to safety
The biggest with environmental hazard.
Tradition rectification directly removes three wastes elution device except the chlorosilane waste liquid of discharge and the waste liquid of cold hydrogenation intermittent discharge at the bottom of weight tower tower
Process, cause elution device treating capacity to increase, eluting column blocking is serious, drip washing alkali charge increases, the filter pressing quantity of slag is big,
Waste water circulation treating capacity increases etc., produce to three waste-removing devices, safe and environment-friendly cause enormous pressure.
Application No. 201210412287.X, entitled " a kind of clearance-type reclaims the method for chlorosilane waste liquid in production of polysilicon
And equipment " patent of invention in disclose a kind of clearance-type and recycle in production of polysilicon chlorosilane in scrubbing tower discharge waste liquid
Method, the steps include: it is that the chlorosilane waste liquid batch (-type) produced from production of polysilicon is entered vaporising device with dividing, logical
Cross control evaporator temperature 120-180 DEG C, during pressure 0.1-0.6MPa, trichlorosilane relatively low for boiling point, Silicon chloride. are steamed
Send out into gaseous state, be then fed into recycling after rectifying column purified treatment.But the shortcoming that the program exists: (1) is because of waste liquid
In containing substantial amounts of metal chloride, wherein obvious with aluminum chloride, the vaporising device of this liquid waste processing uses batch (-type)
Charging, can block feeding line, affect vaporising device and dispose waste liquid, and strengthens labor cleaning's amount simultaneously；(2) this liquid waste processing
Vaporising device batch type, vaporising device top does not has material pipeline to clean in time, evaporation plant equipment can be caused internal and
Agitator blocking frequently, causes vaporising device not dispose waste liquid in time, increases this evaporation plant equipment service work, increases
Drip washing treating capacity, affects polysilicon system and produces.
Application No. 201110221007.2, entitled " negative pressure reclaims waste chlorsilane in polysilicon produced through modified Simens Method
Method " patent of invention in disclose negative pressure reclaim waste chlorsilane in polysilicon produced through modified Simens Method method, its
Step is: collecting discarded chlorosilane and be transported to waste tank, waste tank Stress control is in gauge pressure 20-900KPa；Waste liquid stores up
Chlorosilane waste liquid in tank relies on self pressure reduction to enter the vacuum evaporator of below absolute pressure 20KPa, in vacuum evaporator
Chlorosilane direct gasification under negative pressure becomes chlorosilane gas；By air exhauster by the chlorosilane gas suction chlorine in vacuum evaporator
Silane reclaims storage tank, and liquefaction forms chlorosilane liquid produced；The slag of the residual in vacuum evaporator is hydrolyzed, the most innoxious place
Reason.But the shortcoming that the program exists: it is incomplete that (1) uses negative pressure to reclaim chlorosilane, reclaims chlorosilane the most completely and goes hydrolysis,
Cause material waste；(2) the blocking at inwall containing a large amount of high-boiling components of the residual in vacuum evaporator, labor cleaning's difficulty
Greatly；(3) remaining slag viscosity in vacuum evaporator very big, in going hydrolytic process, pipeline can be caused to be frequently occluded, impact is raw
Produce.
Therefore so that the safe and stable process technique that reclaims continuously of chlorosilane waste liquid has become anxious in whole polysilicon industry
One of bottleneck that need to solve.
Summary of the invention
It is contemplated that one of technical problem solved the most to a certain extent in correlation technique.To this end, the one of the present invention
Purpose is to propose a kind of method and system processing chlorosilane waste liquid, and the method can realize the continuous place to chlorosilane waste liquid
Reason, and the blocking of pipeline can be prevented effectively from.
In one aspect of the invention, the present invention proposes a kind of method processing chlorosilane waste liquid, and described chlorosilane waste liquid contains
Have in trichlorosilane, Silicon chloride., silica flour, polymer and metal chloride at least one, described method includes:
(1) it is evaporated described chlorosilane waste liquid processing, in order to obtain liquid after gaseous light component and evaporation, wherein, described
Gaseous light component contains trichlorosilane and Silicon chloride., and after described evaporation, liquid contains silica flour, polymer and metal chloride；
(2) described gaseous light component is carried out condensation process, in order to obtain the light component of liquid；
(3) light for described liquid component is carried out rectification process, in order to obtain tower overhead gas and tower bottoms, wherein, described tower overhead gas
Containing trichlorosilane, described tower bottoms contains Silicon chloride.；
(4) use silica flour and hydrogen that described tower bottoms is carried out cold hydrogenation treatment, in order to obtain trichlorosilane；And
(5) use lime water that liquid after described evaporation is neutralized process, in order to obtain slag liquid.
The method processing chlorosilane waste liquid according to embodiments of the present invention can realize the continuous processing to chlorosilane waste liquid, thus
Decrease the discharge capacity of waste liquid, and by liquid after the evaporation obtained by evaporation process is neutralized process, can be by strong rotten
The harmful liquid of erosion property is converted into the slag liquid of environment-friendly type, can be prevented effectively from the blocking of pipeline and equipment simultaneously, additionally will evaporation
Process the Silicon chloride. in the light component obtained and carry out separating and being converted into by cold hydrogenation treatment the trichlorosilane of high added value,
Such that it is able to realize recycling of material, thus realize the recovery of chlorosilane 90%.
It addition, the method for process chlorosilane waste liquid according to the above embodiment of the present invention can also have following additional technology spy
Levy:
In some embodiments of the invention, in step (1), in step (1), described evaporation process be temperature be 85～95
Degree Celsius and pressure be to carry out under conditions of 0.15～0.25MPa.Thus, it is possible to significantly improve evaporation efficiency.
In some embodiments of the invention, described evaporation process is carried out in evaporation withdrawer, described evaporation withdrawer
Including body, described internal limits evaporating space, is suitable to be evaporated described chlorosilane waste liquid processing；Chlorosilane
Waste liquid entrance, described chlorosilane waste liquid entrance is arranged at the top of described body；Nitrogen inlet, described nitrogen inlet is arranged at
The top of described body；Silicon chloride. entrance, described Silicon chloride. entrance is arranged on the top of described body；Gaseous light component
Outlet, described gaseous state light fraction outlet is arranged on the top of described body；Steam inlet, described steam inlet is arranged at described
On the sidewall of body；Steam (vapor) outlet, described steam (vapor) outlet is arranged at the bottom of described body；And liquid exports after evaporation, institute
After stating evaporation, liquid outlet is arranged at the bottom of described body.Thus, it is possible to improve evaporation efficiency further.
In some embodiments of the invention, in described evaporation withdrawer, liquid level is 30～75v%.Thus, it is possible to it is notable
Improve the purity of gaseous light component.
In some embodiments of the invention, in step (2), the temperature of the light component of described liquid is 30 degrees Celsius.
In some embodiments of the invention, in step (3), described rectification process is to be 55～58 degrees Celsius in tower top temperature
It is to carry out under the conditions of 0.23～0.28MPa with pressure.Thus, it is possible to significantly improve rectification process efficiency.
In some embodiments of the invention, in step (5), the mass concentration of described lime water is 10%.Thus, it is possible to
Significantly improve neutralisation treatment efficiency.
In some embodiments of the invention, the method for described process chlorosilane waste liquid further includes at and carries out at described neutralization
Before reason, in described evaporation withdrawer, it is passed through nitrogen and Silicon chloride. in advance, in order to liquid after described evaporation is discharged described steaming
Send out space.Thus, it is possible to be prevented effectively from evaporation withdrawer inwall and the blocking of bottom pipe.
In some embodiments of the invention, described neutralisation treatment be when in described evaporation withdrawer liquid level less than 30v% time enter
Row.
In another aspect of the present invention, the present invention proposes a kind of system processing chlorosilane waste liquid, and this system includes:
Vaporising device, described vaporising device is suitable to be evaporated described chlorosilane waste liquid processing, in order to obtain gaseous light component
With liquid after evaporation, wherein, described gaseous light component contains trichlorosilane, Silicon chloride. and metal chloride, after described evaporation
Liquid contains silica flour, metal chloride and polymer；
Condensing unit, described condensing unit is connected with described vaporising device, and is suitable to carry out at condensation described gaseous light component
Reason, in order to obtain the light component of liquid；
Rectifier unit, described rectifier unit is connected with described condensing unit, and is suitable to component light to described liquid and carries out at rectification
Reason, in order to obtaining tower overhead gas and tower bottoms, wherein, described tower overhead gas contains trichlorosilane, and described tower bottoms contains four chlorinations
Silicon；
Cold hydrogenation apparatus, described cold hydrogenation apparatus is connected with described rectifier unit, and is suitable for use with silica flour and hydrogen to described tower
Still liquid carries out cold hydrogenation treatment, in order to obtain trichlorosilane；And
Neutralizing device, described neutralization device is connected with described vaporising device, and is suitable for use with lime water and enters liquid after described evaporation
Row neutralisation treatment, in order to obtain slag liquid.
The system processing chlorosilane waste liquid according to embodiments of the present invention can realize the continuous processing to chlorosilane waste liquid, thus
Decrease the discharge capacity of waste liquid, and by liquid after the evaporation obtained by evaporation process is neutralized process, can be by strong rotten
The harmful liquid of erosion property is converted into the slag liquid of environment-friendly type, can be prevented effectively from the blocking of pipeline and equipment simultaneously, additionally will evaporation
Process the Silicon chloride. in the light component obtained and carry out separating and being converted into by cold hydrogenation treatment the trichlorosilane of high added value,
Such that it is able to realize recycling of material, thus realize the recovery of chlorosilane 90%.
It addition, the system of process chlorosilane waste liquid according to the above embodiment of the present invention can also have following additional technology spy
Levy:
In some embodiments of the invention, described vaporising device is evaporation withdrawer, and described evaporation withdrawer includes: body,
Described internal limits evaporating space, is suitable to be evaporated described chlorosilane waste liquid processing；Chlorosilane waste liquid entrance, institute
State chlorosilane waste liquid entrance and be arranged at the top of described body；Nitrogen inlet, described nitrogen inlet is arranged at the top of described body
Portion；Silicon chloride. entrance, described Silicon chloride. entrance is arranged on the top of described body；Gaseous state light fraction outlet, described gas
State light fraction outlet is arranged on the top of described body；Steam inlet, described steam inlet is arranged on the sidewall of described body；
Steam (vapor) outlet, described steam (vapor) outlet is arranged at the bottom of described body；And liquid outlet after evaporation, liquid outlet after described evaporation
It is arranged at the bottom of described body.Thus, it is possible to significantly improve evaporation efficiency.
In some embodiments of the invention, described evaporation withdrawer farther includes level monitoring device, described level monitoring
Device is arranged on the sidewall of described body, and is suitable to monitor described internal liquid level.Thus, it is possible to be prevented effectively from steaming
Send out withdrawer inwall and the blocking of bottom pipe.
In some embodiments of the invention, described evaporation withdrawer farther includes device for detecting temperature, described temperature monitoring
Device is arranged on the sidewall of described body.
In some embodiments of the invention, the system of described process chlorosilane waste liquid farther includes to control device, described control
Device processed is connected with described level monitoring device and described neutralization device respectively, in order to the liquid level in described vaporising device is less than
Described neutralization device is started during 30v%.
Accompanying drawing explanation
Fig. 1 is the method flow schematic diagram processing chlorosilane waste liquid according to an embodiment of the invention；
Fig. 2 is that the structure processing the evaporation withdrawer used in the method for chlorosilane waste liquid according to an embodiment of the invention is shown
It is intended to；
Fig. 3 is the system structure schematic diagram processing chlorosilane waste liquid according to an embodiment of the invention；
Fig. 4 is the system structure schematic diagram processing chlorosilane waste liquid according to another embodiment of the present invention；
Fig. 5 is the system structure schematic diagram processing chlorosilane waste liquid according to further embodiment of the present invention.
Detailed description of the invention
Embodiments of the invention are described below in detail, and the example of described embodiment is shown in the drawings, the most identical
Or similar label represents same or similar element or has the element of same or like function.Retouch below with reference to accompanying drawing
The embodiment stated is exemplary, it is intended to is used for explaining the present invention, and is not considered as limiting the invention.
In describing the invention, it is to be understood that term " " center ", " longitudinally ", " laterally ", " length ", " width ",
" thickness ", " on ", D score, "front", "rear", "left", "right", " vertically ", " level ", " top ", " end " " interior ", " outward ",
Orientation or the position relationship of the instruction such as " clockwise ", " counterclockwise ", " axially ", " radially ", " circumferential " are based on shown in the drawings
Orientation or position relationship, be for only for ease of describe the present invention and simplify describe rather than instruction or hint indication device or
Element must have specific orientation, with specific azimuth configuration and operation, be therefore not considered as limiting the invention.
In the present invention, unless otherwise clearly defined and limited, term " install ", " being connected ", " connection ", the art such as " fixing "
Language should be interpreted broadly, and connects for example, it may be fixing, it is also possible to be to removably connect, or integral；Can be machinery
Connect, it is also possible to be electrical connection；Can be to be joined directly together, it is also possible to be indirectly connected to by intermediary, can be two units
Connection within part or the interaction relationship of two elements, unless otherwise clear and definite restriction.Ordinary skill for this area
For personnel, above-mentioned term concrete meaning in the present invention can be understood as the case may be.
In the present invention, unless otherwise clearly defined and limited, fisrt feature second feature " on " or D score can be
One directly contacts with second feature, or the first and second features are by intermediary mediate contact.And, fisrt feature
Second feature " on ", " top " and " above " but fisrt feature directly over second feature or oblique upper, or only
Represent that fisrt feature level height is higher than second feature.Fisrt feature second feature " under ", " lower section " and " below "
Can be fisrt feature immediately below second feature or obliquely downward, or be merely representative of fisrt feature level height less than second
Feature.
In one aspect of the invention, the present invention proposes a kind of method processing chlorosilane waste liquid.Reality according to the present invention
Execute example, chlorosilane waste liquid can contain in trichlorosilane, Silicon chloride., silica flour, polymer and metal chloride at least it
One.It should be noted that if no special instructions, herein " polymer " is polymer and the boron chloride of Phosphorous chloride.
Polymer, " metal chloride " is aluminum chloride and calcium chloride.Below with reference to the Fig. 1-2 process chlorine silicon to the embodiment of the present invention
The method of alkane waste liquid is described in detail.According to embodiments of the invention, the method includes:
S100: evaporation process
According to embodiments of the invention, it is evaporated chlorosilane waste liquid processing, such that it is able to obtain liquid after light component and evaporation.
According to embodiments of the invention, chlorosilane waste liquid can be that rectification is at the bottom of except heavy continuous relief liquor at the bottom of tower tower and cold hydrogenation pole cooler
The intermittent discharge waste liquid in portion.According to embodiments of the invention, light component can contain trichlorosilane and Silicon chloride., after evaporation
Liquid can contain silica flour, metal chloride and polymer.According to embodiments of the invention, the condition of evaporation process is not by spy
Not limiting, according to a particular embodiment of the invention, evaporation process can be 85～95 degrees Celsius in temperature and with pressure be
Carry out under conditions of 0.15～0.25MPa.Inventor finds, can significantly improve chlorosilane waste liquid evaporation efficiency under the conditions of being somebody's turn to do,
Thus effectively trichlorosilane and Silicon chloride. are separated from chlorosilane waste liquid.
According to embodiments of the invention, evaporation process can be carried out in evaporation withdrawer.Concrete, with reference to Fig. 2, evaporation
Withdrawer 100 includes body 10, chlorosilane waste liquid entrance 11, nitrogen inlet 12, Silicon chloride. entrance 13, gaseous light group
Separate liquid outlet 17 after mouth 14, steam inlet 15, steam (vapor) outlet 16 and evaporation, according to a particular embodiment of the invention, originally
The internal evaporating space that limits, and be suitable to be evaporated chlorosilane waste liquid processing；Chlorosilane waste liquid entrance is arranged at body
Top, and be suitable in chlorosilane waste liquid supply to evaporating space；Nitrogen inlet is arranged at the top of body, and is suitable to nitrogen
Gas supplies to evaporating space；Silicon chloride. entrance is arranged on the top of body, and is suitable to supply to evaporating sky Silicon chloride.
In between；Gaseous state light fraction outlet is arranged on the top of body, and is suitable to gaseous light component is discharged evaporating space；Liquid after evaporation
Outlet is arranged at the bottom of body, and is suitable to liquid after evaporation is discharged evaporating space；Steam inlet is arranged on the sidewall of body,
And be suitable for use with steam evaporating space is heated；Steam (vapor) outlet is arranged at the bottom of body, and is suitable to the steam of cooling
Discharge heating jacket.According to embodiments of the invention, evaporation withdrawer may further include level monitoring device 18, temperature
Monitoring device 19 and magnetic stirring apparatus 20.According to a particular embodiment of the invention, level monitoring device is arranged at the side of body
On wall, and be suitable to monitor this internal liquid level；Device for detecting temperature is arranged on the sidewall of body.Reality according to the present invention
Executing example, in evaporation withdrawer, liquid level can be 30～75v%.Inventor finds, makes liquid level show after liquid level is too low
Show inaccurate, and be easily caused the condensation recovery process that beavy metal impurity entrance is follow-up, so that reclaim a huge sum of money in chlorosilane
Belong to contaminant overstandard, and if the chlorosilane that the too high solution of liquid level causes metal impurities enters condensation recovery work with liquid form
In sequence, condensing unit is caused to block.Thus, set liquid level a height of 30～75v% scope can ensure that entering smoothly of evaporation process
OK, metals content impurity is less and in obtained chlorosilane.
Concrete, level monitoring device can be liquidometer, when liquid level is higher than 75v% alarm less than 30v% or liquid level,
And increase baffle plate exceeding liquidometer 250mm height inwall, thus after preventing evaporation, liquid blocks；Liquid after the evaporation of bottom
Outlet has the lower insert port of liquidometer before installing valve, and valve；Magnetic stirring apparatus, with deceleration device, is used for
Controlling agitator speed, agitator is with stirring vane, and stirring vane and vaporising device inwall distance are 100～150 millis
Rice, separates the chlorosilane in chlorosilane waste liquid with gas phase by stirring, mixing and heat, then passes through
Chlorosilane is reclaimed in condensation；Gaseous light component outlet conduit has distance-transmission pressure gauge, is used for controlling pressure and exists
0.15～0.25MPa；Nitrogen inlet is forced into 0.35MPa for being passed through nitrogen in vaporising device, in order to will containing silica flour,
After the evaporation of metal chloride, polymer and a small amount of Silicon chloride., hydraulic pressure enters to neutralize in device and with mass concentration is
The lime water of 10% is neutralized reaction, is passed through clean Silicon chloride. for evaporation dress by Silicon chloride. entrance simultaneously
Put and be stirred rinsing, thus after just remaining in the evaporation of vaporising device inwall and bottom pipe, liquid is flushed in neutralizing tank.
S200: condensation process
According to embodiments of the invention, gaseous light component obtained above is carried out condensation process, such that it is able to obtain liquid
The light component of state.According to embodiments of the invention, gaseous light component is carried out condensation process and can use recirculated cooling water.
According to embodiments of the invention, the temperature of the light component of liquid can be 30 degrees Celsius.Thus, it is possible to realize following of material
Ring utilizes, thus avoids the waste of material.
S300: rectification process
According to embodiments of the invention, the light component of liquid derived above is carried out rectification process, such that it is able to obtain tower
Top gas and tower bottoms, according to a particular embodiment of the invention, tower overhead gas can have containing trichlorosilane, and tower bottoms can contain
There is Silicon chloride..According to embodiments of the invention, rectification process can be 55～58 degrees Celsius in tower top temperature and with pressure be
Carry out under the conditions of 0.23～0.28MPa.Inventor finds, the rectification process carried out under the conditions of being somebody's turn to do can significantly improve trichlorosilane
With Silicon chloride. separation efficiency.According to embodiments of the invention, rectification process can use high-efficiency guide sieve-plate tower, tower internal diameter
Being 1100～1300mm, the number of plates is 70～80 pieces, and charging aperture is the 32nd～55 block of column plate, and tower top operation pressure is
0.23～0.28MPaG, operation temperature is 55～58 DEG C, and tower reactor operation pressure is 0.27～0.35MPaG, and operation temperature is
77～79 DEG C, reflux ratio is 43～48.
S400: cold hydrogenation treatment
According to embodiments of the invention, use silica flour and hydrogen that tower bottoms obtained above is carried out cold hydrogenation treatment, thus can
To obtain trichlorosilane.According to embodiments of the invention, cold hydrogenation can be 510～560 degrees Celsius in temperature and with pressure be
Carry out under conditions of 3.0～3.5MPa.In this step, specifically, the chemical equation of generation is: Si+2H2+3SiCl4→
4SiHCl3, from there through cold hydrogenation treatment, can be by trichlorine hydrogen that the converting silicon tetrachloride in chlorosilane waste liquid is high added value
Silicon, and then realize recycling of material.
S500: neutralisation treatment
According to embodiments of the invention, use lime water that liquid after evaporation obtained above is neutralized process, thus can
To obtain slag liquid.According to embodiments of the invention, slag liquid can contain silica flour, calcium silicates, calcium chloride.According to this
Bright embodiment, neutralisation treatment can be carried out in neutralizing tank, and the mass concentration of lime water can be 10%.Root
According to embodiments of the invention, underway and process before, can in advance to evaporation withdrawer in be passed through nitrogen and Silicon chloride.,
Such that it is able to liquid discharges evaporating space after evaporating.Inventor finds, after evaporation, the viscosity of liquid is high, is easily caused and evaporates back
Receive device inwall and bottom pipe blocks, therefore by periodically evaporation being reclaimed from evaporation withdrawer top access Silicon chloride.
Device is stirred rinsing, such that it is able to liquid after the evaporation withdrawer inwall of residual and the evaporation of bottom pipe is flushed to neutralizing tank
In.According to embodiments of the invention, neutralisation treatment can be when evaporating what liquid level in withdrawer was carried out when being less than 30v%.This step
In Zhou, neutralize reaction as follows:
SiHCl3+Ca(OH)2+2H2O→Si(OH)4+CaCl2+H2；
2SiHCl3+3H2O→(HSiO)2O+6HCl；
SiCl4+H2O→H2SiO3+4HCl；
H2SiO3+Ca(OH)2→CaSiO3+2H2O；
2HCl+Ca(OH)2→CaCl2+H2O。
Specifically, when evaporating withdrawer liquid level as little as 30%, by the nitrogen inlet supply nitrogen at evaporation withdrawer top,
Hydraulic pressure after evaporation containing silica flour, metal chloride and polymer can be entered in neutralizing tank during the lime water with 10wt% carries out
And reaction, waste gas eluting column is discharged and delivered to the waste gas obtained from neutralization tank top and processes, simultaneously by obtained slag
Liquid supplies to pressure filter after delivering to stirring pool stirring and carries out filter pressing, it addition, in order to avoid evaporation withdrawer inwall and lower tube
Road blocks, and accesses Silicon chloride. from evaporation withdrawer top and periodically is stirred rinsing to evaporation withdrawer, thus by residual
After the evaporation withdrawer inwall stayed and the evaporation of bottom pipe, liquid is flushed in neutralizing tank.Thus, by neutralisation treatment, permissible
The harmful liquid in chlorosilane waste liquid with severe corrosive is converted into environment-friendly type containing silica flour, calcium silicates and calcium chloride slag
Liquid.
The method processing chlorosilane waste liquid according to embodiments of the present invention can realize the continuous processing to chlorosilane waste liquid, thus
Decrease the discharge capacity of waste liquid, and by liquid after the evaporation obtained by evaporation process is neutralized process, can be by strong rotten
The harmful liquid of erosion property is converted into the slag liquid of environment-friendly type, can be prevented effectively from the blocking of pipeline and equipment simultaneously, additionally will evaporation
Process the Silicon chloride. in the light component obtained and carry out separating and being converted into by cold hydrogenation treatment the trichlorosilane of high added value,
Such that it is able to realize recycling of material, thus realize the recovery of chlorosilane 90%.
In another aspect of the present invention, the present invention proposes a kind of system processing chlorosilane waste liquid.Below with reference to figure
3-4 processes the system of chlorosilane waste liquid and is described in detail the embodiment of the present invention.According to embodiments of the invention, should
System includes:
Vaporising device 100: according to embodiments of the invention, vaporising device 100 is suitable to be evaporated chlorosilane waste liquid processing,
Such that it is able to obtain liquid after light component and evaporation.According to embodiments of the invention, chlorosilane waste liquid can be that rectification is except weight tower tower
Intermittent discharge waste liquid bottom the continuous relief liquor at the end and cold hydrogenation pole cooler.According to embodiments of the invention, light component is permissible
Containing trichlorosilane and Silicon chloride., after evaporation, liquid can contain silica flour, metal chloride and polymer.According to the present invention's
Embodiment, the condition of evaporation process is not particularly restricted, and according to a particular embodiment of the invention, evaporation process can be in temperature
Degree is 85～95 degrees Celsius and pressure is to carry out under conditions of 0.15～0.25MPa.Inventor finds, can be notable under the conditions of being somebody's turn to do
Improve chlorosilane waste liquid evaporation efficiency, thus effectively trichlorosilane and Silicon chloride. are separated from chlorosilane waste liquid.According to this
Inventive embodiment, evaporation process can be carried out in evaporation withdrawer.Concrete, evaporation withdrawer is as in figure 2 it is shown, steam
Send out withdrawer 100 and include body 10, chlorosilane waste liquid entrance 11, nitrogen inlet 12, Silicon chloride. entrance 13, gaseous light
Liquid outlet 17 after component outlet 14, steam inlet 15, steam (vapor) outlet 16 and evaporation, according to a particular embodiment of the invention,
This internal evaporating space that limits, and be suitable to be evaporated chlorosilane waste liquid processing；Chlorosilane waste liquid entrance is arranged at body
Top, and be suitable to the supply of chlorosilane waste liquid in evaporating space；Nitrogen inlet is arranged at the top of body, and be suitable to by
Nitrogen supplies to evaporating space；Silicon chloride. entrance is arranged on the top of body, and is suitable to Silicon chloride. supply to evaporation
In space；Gaseous state light fraction outlet is arranged on the top of body, and is suitable to gaseous light component is discharged evaporating space；After evaporation
Liquid outlet is arranged at the bottom of body, and is suitable to liquid after evaporation is discharged evaporating space；Steam inlet is arranged at the sidewall of body
On, and be suitable for use with steam evaporating space is heated；Steam (vapor) outlet is arranged at the bottom of body, and is suitable to cooling
Steam discharges heating jacket.According to embodiments of the invention, evaporation withdrawer may further include level monitoring device 18,
Device for detecting temperature 19 and magnetic stirring apparatus 20.According to a particular embodiment of the invention, monitoring device 18 is arranged at body
On sidewall, and be suitable to monitor this internal liquid level；Device for detecting temperature is arranged on the sidewall of body.According to the present invention's
Embodiment, in evaporation withdrawer, liquid level can be 30～75v%.Inventor finds, makes liquid level after liquid level is too low
Display is inaccurate, and is easily caused the condensation recovery process that beavy metal impurity entrance is follow-up, so that reclaim weight in chlorosilane
Metal impurities exceed standard, and if the chlorosilane that the too high solution of liquid level causes metal impurities enters condensation recovery with liquid form
In operation, condensing unit is caused to block.Thus, set liquid level a height of 30～75v% scope can ensure that the smooth of evaporation process
Carry out, and in obtained chlorosilane, metals content impurity is less.
Condensing unit 200: according to embodiments of the invention, condensing unit 200 is connected with vaporising device 100, and be suitable to by
Gaseous light component obtained above carries out condensation process, such that it is able to obtain the light component of liquid.Enforcement according to the present invention
Example, carries out condensation process to gaseous light component and can use recirculated cooling water.According to embodiments of the invention, liquid is light
The temperature of component can be 30 degrees Celsius.Thus, it is possible to realize recycling of material, thus avoid the wave of material
Take.
Rectifier unit 300: according to embodiments of the invention, rectifier unit 300 is connected with condensing unit 200, and is suitable to
The light component of liquid derived above is carried out rectification process, such that it is able to obtain tower overhead gas and tower bottoms, according to the present invention
Specific embodiment, tower overhead gas can have containing trichlorosilane, and tower bottoms can contain Silicon chloride..According to the present invention's
Embodiment, rectification process can be 55～58 degrees Celsius and pressure is to carry out under the conditions of 0.23～0.28MPa in tower top temperature.Send out
A person of good sense finds, the rectification process carried out under the conditions of being somebody's turn to do can significantly improve trichlorosilane and Silicon chloride. separation efficiency.According to this
Inventive embodiment, rectification process can use high-efficiency guide sieve-plate tower, tower internal diameter to be 1100～1300mm, and the number of plates is
70～80 pieces, charging aperture is the 32nd～55 block of column plate, and tower top operation pressure is 0.23～0.28MPaG, and operation temperature is 55～58 DEG C,
Tower reactor operation pressure is 0.27～0.35MPaG, and operation temperature is 77～79 DEG C, and reflux ratio is 43～48.
Cold hydrogenation apparatus 400: according to embodiments of the invention, cold hydrogenation apparatus 400 is connected with rectifier unit 300, and suitable
Tower bottoms obtained above is carried out cold hydrogenation treatment, such that it is able to obtain trichlorosilane in using silica flour and hydrogen.According to this
Inventive embodiment, cold hydrogenation can be 510～560 DEG C and pressure is to carry out under conditions of 3.0～3.5MPaG in temperature.Should
In step, specifically, the chemical equation of generation is: Si+2H2+3SiCl4→4SiHCl3, at cold hydrogenation
Reason, can be the trichlorosilane of high added value by the converting silicon tetrachloride in chlorosilane waste liquid, and then realizes the circulation profit of material
With.
Neutralize device 500: according to embodiments of the invention, neutralize device 500 and be connected with vaporising device 100, use stone
Buck is neutralized process to liquid after evaporation obtained above, such that it is able to obtain slag liquid.According to embodiments of the invention,
Underway and process before, can in advance to evaporation withdrawer in be passed through nitrogen and Silicon chloride., such that it is able to will evaporation after
Liquid discharges evaporating space.Inventor finds, after evaporation, the viscosity of liquid is high, is easily caused evaporation withdrawer inwall and lower tube
Road blocks, therefore by periodically being stirred rinsing to evaporation withdrawer from evaporation withdrawer top access Silicon chloride.,
Such that it is able to liquid after the evaporation withdrawer inwall of residual and the evaporation of bottom pipe is flushed in neutralizing tank.Specifically, pass through
The nitrogen inlet supply nitrogen at evaporation withdrawer top, can be by liquid after the evaporation containing silica flour, metal chloride and polymer
In press-in neutralizing tank, the lime water with 10wt% is neutralized reaction, discharges and deliver to give up from neutralizing tank top by the waste gas obtained
Gas eluting column processes, and supplies to pressure filter simultaneously and carry out filter pressing, separately after obtained slag liquid is delivered to stirring pool stirring
Outward, in order to avoid evaporation withdrawer inwall and bottom pipe block, access Silicon chloride. from evaporation withdrawer top regular
It is stirred rinsing to evaporation withdrawer, thus liquid after the evaporation withdrawer inwall of residual and the evaporation of bottom pipe is flushed to
In neutralizing tank.Thus, by neutralisation treatment, the harmful liquid in chlorosilane waste liquid with severe corrosive can be converted into ring
Guarantor's type containing silica flour, calcium silicates and calcium chloride slag liquid.
The system processing chlorosilane waste liquid according to embodiments of the present invention can realize the continuous processing to chlorosilane waste liquid, thus
Decrease the discharge capacity of waste liquid, and by liquid after the evaporation obtained by evaporation process is neutralized process, can be by strong rotten
The harmful liquid of erosion property is converted into the slag liquid of environment-friendly type, can be prevented effectively from the blocking of pipeline and equipment simultaneously, additionally will evaporation
Process the Silicon chloride. in the light component obtained and carry out separating and being converted into by cold hydrogenation treatment the trichlorosilane of high added value,
Such that it is able to realize recycling of material, thus realize the recovery of chlorosilane 90%.
As shown in Figure 4, the system of described process chlorosilane waste liquid farther includes:
Control device 600: according to embodiments of the invention, control device 600 and liquid level detection device 18 and neutralization dress
Put 500 to be connected, and be suitable to starting neutralization device 500 when the liquid level in vaporising device 100 is less than 30v%.
Below with reference to specific embodiment, present invention is described, it should be noted that these embodiments are the most descriptive
, and limit the present invention never in any form.
Embodiment
With reference to Fig. 5, rectification is supplied extremely except the continuous relief liquor at the bottom of weight tower tower and the intermittent discharge waste liquid bottom the cooler of cold hydrogenation pole
In first storage tank 700, then by pump p1 by chlorosilane waste liquid supply to vaporising device 100 is evaporated processing, obtain
Liquid after gaseous light component and evaporation, wherein gaseous light component is discharged into condensing unit 200 entering from vaporising device 100 top
Row condensation process, delivers to light for the liquid obtained component in the second storage tank 800, then uses light group of the liquid that pump p2 will obtain
Dispensing carries out rectification process to rectifier unit 300, obtains the tower overhead gas containing trichlorosilane and the tower reactor containing Silicon chloride.
Liquid, supplies the tower bottoms containing Silicon chloride. the coldest hydrogenation apparatus 400 and carries out cold hydrogenation with silica flour and hydrogen, thus
It is the trichlorosilane of high added value by converting silicon tetrachloride；Meanwhile, when vaporising device liquid level as little as 30%, filled by evaporation
The nitrogen inlet supply nitrogen in top set portion, enters to neutralize device by hydraulic pressure after the evaporation containing silica flour, metal chloride and polymer
In 500, the lime water with 10wt% is neutralized reaction, discharges and deliver to waste gas pouring by the waste gas obtained from neutralizing device top
Wash tower to process, supply to pressure filter after obtained slag liquid is delivered to stirring pool stirring simultaneously and carry out filter pressing, it addition,
In order to avoid evaporation withdrawer inwall and bottom pipe block, access four from the Silicon chloride. entrance at evaporation withdrawer top
Evaporation withdrawer periodically is stirred rinsing by silicon chloride, thus by the evaporation withdrawer inwall remained and the evaporation of bottom pipe
Rear liquid is flushed to neutralize in device.
The polycrystalline silicon production line of 5000t/a, cold hydrogenation unit quencher bottom discharge waste liquid is 0.9t/h, rectification cell heavy constituent
Discharge waste liquid is 0.55t/h, by chlorosilane devil liquor recovery equipment recyclable chlorosilane 1.21t/h, runs 8000 according to annual
Hour calculate, 1 year recyclable 9680 tons of chlorosilane, save Calx consume 9570 tons, save produce water 44695m3；
According to existing market price, trichlorosilane 5400 yuan/ton, Calx 600 yuan/ton, produce 4.5 yuan/m of water3Calculate:
Save trichlorosilane expense=9680 ton × 5400 yuan/ton=52272000 yuan；
Save Calx consumption costs=9570 ton × 600 yuan/ton=5742000 yuan；
Save and produce m3 × 4.5 yuan, water consumption expense=44695/m3=201127 unit；
Then save economic benefit=saving trichlorosilane expense+saving Calx consumption costs+saving and produce water consumption expense
=5821.51 ten thousand yuan.
In the description of this specification, reference term " embodiment ", " some embodiments ", " example ", " concrete example ",
Or specific features, structure, material or the feature bag that the description of " some examples " etc. means to combine this embodiment or example describes
It is contained at least one embodiment or the example of the present invention.In this manual, to the schematic representation of above-mentioned term necessarily
It is directed to identical embodiment or example.And, the specific features of description, structure, material or feature can be arbitrary
Individual or multiple embodiment or example combine in an appropriate manner.Additionally, in the case of the most conflicting, the skill of this area
The feature of the different embodiments described in this specification or example and different embodiment or example can be combined by art personnel
And combination.
Although above it has been shown and described that embodiments of the invention, it is to be understood that above-described embodiment is exemplary,
Being not considered as limiting the invention, those of ordinary skill in the art within the scope of the invention can be to above-described embodiment
It is changed, revises, replaces and modification.
Claims (7)
1. the method processing chlorosilane waste liquid, described chlorosilane waste liquid contains trichlorosilane, Silicon chloride., silica flour, gathers
At least one in compound and metal chloride, it is characterised in that described method includes:
(1) it is evaporated described chlorosilane waste liquid processing, in order to obtain liquid after gaseous light component and evaporation, wherein, described
Gaseous light component contains trichlorosilane and Silicon chloride., and after described evaporation, liquid contains silica flour, polymer and metal chloride；
(2) described gaseous light component is carried out condensation process, in order to obtain the light component of liquid；
(3) light for described liquid component is carried out rectification process, in order to obtain tower overhead gas and tower bottoms, wherein, described tower overhead gas
Containing trichlorosilane, described tower bottoms contains Silicon chloride.；
(4) use silica flour and hydrogen that described tower bottoms is carried out cold hydrogenation treatment, in order to obtain trichlorosilane；And
(5) use lime water that liquid after described evaporation is neutralized process, in order to obtain slag liquid,
Wherein, in step (1), described evaporation process is that temperature is 85～95 degrees Celsius and pressure is 0.15～0.25MPa
Under the conditions of carry out,
Described evaporation process is carried out in evaporation withdrawer, and described evaporation withdrawer includes:
Body, described internal limits evaporating space, is suitable to be evaporated described chlorosilane waste liquid processing；
Chlorosilane waste liquid entrance, described chlorosilane waste liquid entrance is arranged at the top of described body；
Nitrogen inlet, described nitrogen inlet is arranged at the top of described body；
Silicon chloride. entrance, described Silicon chloride. entrance is arranged on the top of described body；
Gaseous state light fraction outlet, described gaseous state light fraction outlet is arranged on the top of described body；
Steam inlet, described steam inlet is arranged on the sidewall of described body；
Steam (vapor) outlet, described steam (vapor) outlet is arranged at the bottom of described body；And
Liquid outlet after evaporation, after described evaporation, liquid outlet is arranged at the bottom of described body,
In described evaporation withdrawer, liquid level is 30～75v%,
Wherein, before carrying out described neutralisation treatment, in described evaporation withdrawer, it is passed through nitrogen and Silicon chloride. in advance, with
Just liquid after described evaporation is discharged described evaporating space.
The method of process chlorosilane waste liquid the most according to claim 1, it is characterised in that in step (2), described
The temperature of the light component of liquid is 30 degrees Celsius.
The method of process chlorosilane waste liquid the most according to claim 1, it is characterised in that in step (3), described
Rectification process is 55～58 degrees Celsius and pressure is to carry out under the conditions of 0.23～0.28MPa in tower top temperature.
The method of process chlorosilane waste liquid the most according to claim 1, it is characterised in that in step (5), described
The mass concentration of lime water is 10%.
The method of process chlorosilane waste liquid the most according to claim 1, it is characterised in that described neutralisation treatment is to work as
In described evaporation withdrawer, liquid level is carried out when being less than 30v%.
6. the system processing chlorosilane waste liquid, it is characterised in that including:
Vaporising device, described vaporising device is suitable to be evaporated described chlorosilane waste liquid processing, in order to obtain gaseous light component
With liquid after evaporation, wherein, described gaseous light component contains trichlorosilane, Silicon chloride. and metal chloride, after described evaporation
Liquid contains silica flour, metal chloride and polymer；
Condensing unit, described condensing unit is connected with described vaporising device, and is suitable to carry out at condensation described gaseous light component
Reason, in order to obtain the light component of liquid；
Rectifier unit, described rectifier unit is connected with described condensing unit, and is suitable to component light to described liquid and carries out at rectification
Reason, in order to obtaining tower overhead gas and tower bottoms, wherein, described tower overhead gas contains trichlorosilane, and described tower bottoms contains four chlorinations
Silicon；
Cold hydrogenation apparatus, described cold hydrogenation apparatus is connected with described rectifier unit, and is suitable for use with silica flour and hydrogen to described tower
Still liquid carries out cold hydrogenation treatment, in order to obtain trichlorosilane；And
Neutralizing device, described neutralization device is connected with described vaporising device, and is suitable for use with lime water and enters liquid after described evaporation
Row neutralisation treatment, in order to obtain slag liquid,
Wherein, described evaporation process is that temperature is 85～95 degrees Celsius and pressure is to carry out under conditions of 0.15～0.25MPa,
Described vaporising device is evaporation withdrawer, and described evaporation withdrawer includes:
Body, described internal limits evaporating space, is suitable to be evaporated described chlorosilane waste liquid processing；
Chlorosilane waste liquid entrance, described chlorosilane waste liquid entrance is arranged at the top of described body；
Nitrogen inlet, described nitrogen inlet is arranged at the top of described body；
Silicon chloride. entrance, described Silicon chloride. entrance is arranged on the top of described body；
Gaseous state light fraction outlet, described gaseous state light fraction outlet is arranged on the top of described body；
Steam inlet, described steam inlet is arranged on the sidewall of described body；
Steam (vapor) outlet, described steam (vapor) outlet is arranged at the bottom of described body；And
Liquid outlet after evaporation, after described evaporation, liquid outlet is arranged at the bottom of described body；
Wherein, described evaporation withdrawer farther includes level monitoring device, and described level monitoring device is arranged at described body
Sidewall on, and be suitable to monitor described internal liquid level,
The system of described process chlorosilane waste liquid farther include control device, described control device respectively with described level monitoring
Device is connected with described neutralization device, in order to start described neutralization device when the liquid level in described vaporising device is less than 30v%.
The system of process chlorosilane waste liquid the most according to claim 6, it is characterised in that described evaporation withdrawer enters one
Step includes that device for detecting temperature, described device for detecting temperature are arranged on the sidewall of described body.
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| CN106621757B (en) * | 2017-02-21 | 2022-09-16 | 德山化工（浙江）有限公司 | Chlorosilane analysis waste gas recovery treatment device and treatment method |
| CN109607548A (en) * | 2018-12-29 | 2019-04-12 | 内蒙古自治区浩森新材料开发有限公司 | A kind of method and device using polysilicon waste production silicon tetrachloride |
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| CN102234112B (en) * | 2010-09-30 | 2012-06-27 | 河南尚宇新能源股份有限公司 | Method for rectifying trichlorosilane |
| CN102849745B (en) * | 2012-09-24 | 2014-08-06 | 华陆工程科技有限责任公司 | Dust removal process and system for trichlorosilane production |
| CN102910633B (en) * | 2012-10-25 | 2015-01-14 | 新特能源股份有限公司 | Method and equipment for intermittently recycling waste liquid of chlorosilane during polycrystalline silicon production |
| CN103408023A (en) * | 2013-07-19 | 2013-11-27 | 中国恩菲工程技术有限公司 | Method and equipment for treatment of chlorosilane-containing waste liquid |
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