CN107445169A - A kind of system and method for preparing elementary silicon - Google Patents
A kind of system and method for preparing elementary silicon Download PDFInfo
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- CN107445169A CN107445169A CN201710683916.5A CN201710683916A CN107445169A CN 107445169 A CN107445169 A CN 107445169A CN 201710683916 A CN201710683916 A CN 201710683916A CN 107445169 A CN107445169 A CN 107445169A
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- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/02—Silicon
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- C01B33/023—Preparation by reduction of silica or free silica-containing material
- C01B33/025—Preparation by reduction of silica or free silica-containing material with carbon or a solid carbonaceous material, i.e. carbo-thermal process
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Abstract
The present invention relates to a kind of system and method for preparing elementary silicon.The system includes：Pyrolysis unit, dosing, elementary silicon production unit, elementary silicon refinery unit and generator unit.Wherein, pyrolysis unit includes pyrolysis installation and fluidized gasification device, and generator unit includes burner, steam generation device and TRT.Pyrolysis installation is connected with fluidized gasification device, dosing is connected with pyrolysis installation, fluidized gasification device, elementary silicon production unit respectively, elementary silicon refinery unit is connected with elementary silicon production unit, burner is connected with pyrolysis installation, steam generation device respectively, and TRT is connected with steam generation device.Whole technique realizes that electric energy is self-sustaining, fuel is self-sustaining, and the elementary silicon of output high-quality, has higher economic benefit.
Description
Technical field
The invention belongs to the preparation field of elementary silicon, in particular it relates to a kind of system and method for preparing elementary silicon.
Background technology
Tradition prepare the carbonaceous reducing agent of elementary silicon for charcoal, petroleum coke, bituminous coal, it is necessary to use of arranging in pairs or groups can be only achieved it is best
Reduction effect.Charcoal plays conclusive effect as one of most important carbonaceous reducing agent in the smelting of silica.But
It is that domestic charcoal is substantially earth kiln production, small scale, pyrolysis temperature by virtue of experience judges, makes charcoal and produces a large amount of flue gases, causes
Air pollution, thus production is severely limited, to shorten the stewing kiln time, the later stage injects substantial amounts of water reduction charcoal for part kiln factory
Temperature, cause charcoal water content extremely unstable, the result of laboratory test of charcoal shows that total moisture content is extremely unstable, average value 44%,
The fluctuation of dispensing is not only caused, have impact on product quality, while add energy consumption.
In recent years, because country implements ecological construction, control forest felling, protect forest resources, into everybody common recognition.
Some areas are expressly provided at present, forbid deforestation to make charcoal, some areas also specify the specific time for stopping using charcoal, charcoal
Source it is just more limited.
The big province of elementary silicon yield of China is followed successively by Xinjiang, Yunnan, Sichuan.In addition to Xinjiang, Yunnan and Sichuan are again simultaneously bamboos
The place of production of material (such as mao bamboon), reserves very abundant.Traditional big lake fishing and crop greenhouse need substantial amounts of mao bamboon, now
Big lake fishing is limited, and crop greenhouse is supported with steel construction instead of mao bamboon, other light industry products such as demand such as summer sleeping mat, bamboo chopsticks
Amount also reduces so that mao bamboon price drop range is serious, and withered bamboo of mao bamboon processing waste material, leftover pieces, intermountain etc. is difficult by, directly
It is discarded.
The content of the invention
In view of the shortcomings of the prior art, the invention provides a kind of system and method for preparing elementary silicon.This technique can solve
Certainly the problem of bamboo wood production capacity surplus, while bamboo wood is subjected to sufficient recycling, as the carbonaceous of elementary silicon production
Reducing agent, is greatly improved the product quality of elementary silicon, while realizes that the use of system can balance, and without outer energy supply source, reduces into
This.
The system provided by the invention for preparing elementary silicon, including：
Pyrolysis unit, including pyrolysis installation and fluidized gasification device,
The pyrolysis installation is provided with bamboo wood entrance, gasification gas entrance, bamboo charcoal outlet and pyrolysis oil gas vent；
The fluidized gasification device is provided with bamboo charcoal entrance and gasification gas exit, and the bamboo charcoal entrance fills with the pyrolysis
The bamboo charcoal outlet put is connected, and the gasification gas outlet is connected with the gasification gas entrance of the pyrolysis installation；
Dosing, exported provided with silica entrance, petroleum coke entrance, bituminous coal entrance, bamboo charcoal entrance and compound, the bamboo
Charcoal entrance is connected with the bamboo charcoal outlet of the pyrolysis installation；
Elementary silicon production unit, exported provided with compound entrance and liquid silicon, the compound entrance and the charger sheet
The compound outlet of member is connected；
Elementary silicon refinery unit, exported provided with gas access, liquid silicon entrance and ingot casting silicon, the liquid-state silicon entrance and institute
The liquid silicon outlet for stating elementary silicon production unit is connected；
Generator unit, including burner, steam generation device and TRT；
The burner is provided with pyrolysis oil gas entrance, air intake and high-temperature flue gas outlet, the pyrolysis oil gas vent
It is connected with the pyrolysis oil gas vent of the pyrolysis installation；
The steam generation device is provided with high-temperature flue gas entry, water inlet, steam (vapor) outlet and low-temperature flue gas outlet, the height
Warm smoke inlet is connected with the high-temperature flue gas outlet of the burner；
The TRT is provided with steam inlet, condensation-water drain and generating set, the steam inlet and the steam
The steam (vapor) outlet of generation device is connected.
In some embodiments of the invention, the elementary silicon production unit is additionally provided with cooling water inlet and backwater outlet,
The backwater outlet is connected with the water inlet of the steam generation device；The system also includes cooling water circulation unit, described
Cooling water circulation unit includes heat-exchanger rig and cooling device；
The heat-exchanger rig is provided with low-temperature flue gas entrance, combustion air inlet, preheated air outlet, exhanst gas outlet and condensation
Water out, the low-temperature flue gas entrance are connected with the low-temperature flue gas outlet of the steam generation device；The preheated air outlet
It is connected with the air intake of the burner；
The cooling device, which is provided with, condenses water inlet and coolant outlet, described to condense water inlet and the heat-exchanger rig
Water out is condensed to be connected；The coolant outlet is connected with the cooling water inlet of the elementary silicon production unit.
In some embodiments of the invention, the TRT is connected with the elementary silicon production unit, the silicon list
Electric energy needed for matter production unit comes from the TRT.
In some embodiments of the invention, the water of the condensation-water drain of the TRT and the steam generation device
Entrance is connected.
The method provided by the invention that elementary silicon is prepared using said system, is comprised the following steps：
Bamboo wood is sent into the pyrolysis installation to be pyrolyzed, obtains bamboo charcoal and pyrolysis oil gas；
The bamboo charcoal is respectively fed to fluidized gasification device and the dosing；
The bamboo charcoal is gasified in fluidized gasification device, obtains gasification gas；
The gasification gas is sent into the pyrolysis installation, is used to be pyrolyzed the bamboo wood as fuel；
Silica, petroleum coke, bituminous coal are sent into the dosing, dispensing is carried out with the bamboo charcoal, obtains compound；
The compound is sent into the elementary silicon production unit to be reacted, obtains liquid silicon；
The liquid silicon is sent into the elementary silicon refinery unit, and is passed through air or oxygen, carries out refinement oxide removing
Aluminium and calcium in the liquid silicon, obtain ingot casting silicon；
The pyrolysis oil pneumatic transmission is entered in the burner to be burnt, obtains high-temperature flue gas；
The high-temperature flue gas is sent into the steam generation device and exchanged heat with water, obtains steam and low-temperature flue gas；
The steam is sent into the TRT to be generated electricity, obtains electric energy and condensed water.
In some embodiments of the invention, also comprise the following steps：
The low-temperature flue gas and combustion air are exchanged heat, obtain preheated air and condensate；
The preheated air is sent into the burner, burnt with the pyrolysis oil gas；
The elementary silicon production unit will be sent into after the condensation water cooling, for cooling down the elementary silicon production unit,
Obtain backwater；
The backwater is sent into the steam generation device, is exchanged heat with the high-temperature flue gas, prepares the steam.
In some embodiments of the invention, electric energy caused by the TRT is used for for elementary silicon production list
Member power supply.
In some embodiments of the invention, the condensed water is sent into the steam generation device and prepares the steaming
Vapour.
In some embodiments of the invention, the petroleum coke, the bituminous coal, the weight ratio of the bamboo charcoal are (60-70)：
(5-10)：(20-40).
In some embodiments of the invention, the pyrolysis temperature of the bamboo wood is 500 DEG C -800 DEG C.
The present invention realizes the recycling of bamboo wood, realizes the self-sustaining with energy of elementary silicon production, reduces elementary silicon
Production cost.
The present invention uses oil gas direct combustion technique, improves the thermal efficiency of system, and the pyrolysis oil for solving complicated component makes
With having prevented the generation of sewage.
In addition, the present invention gasifies a part of bamboo charcoal, obtained gasification gas is used to be pyrolyzed bamboo wood as fuel, fully profit
With bamboo charcoal, solves the personal energy of pyrolysis installation.
The additional aspect and advantage of the present invention will be set forth in part in the description, and will partly become from the following description
Obtain substantially, or recognized by the practice of the present invention.
Brief description of the drawings
Fig. 1 is a kind of structural representation of system for preparing elementary silicon in the embodiment of the present invention.
Fig. 2 is a kind of process chart for preparing elementary silicon in the embodiment of the present invention.
Embodiment
Below in conjunction with drawings and examples, the embodiment of the present invention is described in more details, so as to energy
The advantages of enough more fully understanding the solution of the present invention and its various aspects.However, specific embodiments described below and reality
Example is applied to be for illustrative purposes only, rather than limitation of the present invention.
The present invention uses cheap bamboo wood as raw material, after bamboo wood pyrolysis, obtained a bamboo charcoal part and petroleum coke, bituminous coal one
Rise and be used as carbonaceous reducing agent to prepare elementary silicon, another part vaporizing system gasification gas, obtained gasification of coal with alkali silica reaction
Gas is used to be pyrolyzed bamboo wood as fuel；Obtained pyrolysis oil gas is changed into steam after burning, exchanging heat, and steam is used to generate electricity.
The system provided by the invention for preparing elementary silicon, including：
Pyrolysis unit, including pyrolysis installation and fluidized gasification device,
Pyrolysis installation is provided with bamboo wood entrance, gasification gas entrance, bamboo charcoal outlet and pyrolysis oil gas vent；
Fluidized gasification device is provided with bamboo charcoal entrance and gasification gas exit, the bamboo charcoal outlet of bamboo charcoal entrance and pyrolysis installation
It is connected, gasification gas outlet is connected with the gasification gas entrance of pyrolysis installation；
Dosing, is exported provided with silica entrance, petroleum coke entrance, bituminous coal entrance, bamboo charcoal entrance and compound, and bamboo charcoal enters
Mouth is connected with the bamboo charcoal outlet of pyrolysis installation；
Elementary silicon production unit, exported provided with compound entrance and liquid silicon, the mixing of compound entrance and dosing
Material outlet is connected；
Elementary silicon refinery unit, exported provided with gas access, liquid silicon entrance and ingot casting silicon, liquid-state silicon entrance and elementary silicon
The liquid silicon outlet of production unit is connected；
Generator unit, including burner, steam generation device and TRT；
Burner is provided with pyrolysis oil gas entrance, air intake and high-temperature flue gas outlet, and pyrolysis oil gas vent fills with pyrolysis
The pyrolysis oil gas vent put is connected；
Steam generation device is provided with high-temperature flue gas entry, water inlet, steam (vapor) outlet and low-temperature flue gas outlet, high-temperature flue gas and entered
Mouth is connected with the high-temperature flue gas outlet of burner；
TRT is provided with steam inlet, condensation-water drain and generating set, the steaming of steam inlet and steam generation device
Vapor outlet is connected.
The present invention realizes the recycling of bamboo wood, realizes the self-sustaining with energy of elementary silicon production, reduces elementary silicon
Production cost.
The present invention uses oil gas direct combustion technique, improves the thermal efficiency of system, and the pyrolysis oil for solving complicated component makes
With having prevented the generation of sewage.
In addition, the present invention gasifies a part of bamboo charcoal, obtained gasification gas is used to be pyrolyzed bamboo wood as fuel, fully profit
With bamboo charcoal, solves the personal energy of pyrolysis installation.
In some embodiments of the invention, above-mentioned elementary silicon production unit is additionally provided with cooling water inlet and backwater outlet,
Backwater outlet is connected with the water inlet of steam generation device；Said system also includes cooling water circulation unit, cooling water circulation list
Member includes heat-exchanger rig and cooling device.
Heat-exchanger rig is provided with low-temperature flue gas entrance, combustion air inlet, preheated air outlet, exhanst gas outlet and condensate and gone out
Mouthful, low-temperature flue gas entrance is connected with the low-temperature flue gas outlet of steam generation device；Preheated air exports the air with burner
Entrance is connected.
Cooling device, which is provided with, condenses water inlet and coolant outlet, condenses the condensation water out phase of water inlet and heat-exchanger rig
Even；Coolant outlet is connected with the cooling water inlet of elementary silicon production unit.
In other embodiments of the present invention, TRT is connected with elementary silicon production unit, elementary silicon production unit
Required electric energy carrys out self-generating device.
Caused electric energy is used to supply elementary silicon production unit, reduces the cost of whole technique.
The condensed water of TRT can also be used for preparing steam, in some embodiments of the invention, TRT it is cold
Condensate outlet is connected with the water inlet of steam generation device.
Fig. 1 show the preferred embodiment that the present invention prepares the system of elementary silicon, wherein, pyrolysis installation is revolving bed 1, is matched somebody with somebody
Material unit is batch bin 2, and elementary silicon production unit is burried arc furnace 3, and elementary silicon refinery unit is silicon bag 4, and burner is combustion
Room 5 is burnt, steam generation device is waste heat boiler 6, and TRT is steam turbine 7, and heat-exchanger rig is heat exchanger 8, cooling device
For cooling tower 9, fluidized gasification device is fluid bed 10.In addition, the system shown in Fig. 1 also includes being used into silicon bag 4 blow
Air compressor machine 11.
Whole system realizes that electric energy is self-sustaining, fuel is self-sustaining, and the elementary silicon of output high-quality, has higher economic effect
Benefit.
Revolving bed 1 is provided with bamboo wood entrance 101, bamboo charcoal outlet 102, pyrolysis oil gas vent 103 and gasification gas entry 104.
Batch bin 2 is provided with silica entrance 201, petroleum coke entrance 202, bituminous coal entrance 203, bamboo charcoal entrance 204 and compound
Outlet 205.Wherein, bamboo charcoal entrance 204 is connected with the bamboo charcoal outlet 102 of revolving bed 1.
Burried arc furnace 3 is provided with compound entrance 301, liquid silicon outlet 302, cooling water inlet 303,304 and of backwater outlet
Electric energy entrance 305.Wherein, compound entrance 301 is connected with the compound outlet 205 of batch bin 2.
Silicon bag 4 is provided with gas access 401, liquid silicon entrance 402 and ingot casting silicon outlet 403.Wherein, liquid silicon entrance 402
It is connected with the liquid silicon outlet 302 of burried arc furnace 3.
Combustion chamber 5 is provided with pyrolysis oil gas entrance 501, air intake 502 and high-temperature flue gas outlet 503.Wherein, it is pyrolyzed oil gas
Entrance 501 is connected with the pyrolysis oil gas vent 103 of revolving bed 1.
Waste heat boiler 6 is provided with high-temperature flue gas entry 601, water inlet 602, steam (vapor) outlet 603 and low-temperature flue gas outlet 604.
Wherein, high-temperature flue gas entry 601 is connected with the high-temperature flue gas outlet 503 of combustion chamber 5.
Steam turbine 7 is provided with steam inlet 701, condensation-water drain 702 and electrical power output 703.Wherein, steam inlet 701
It is connected with the steam (vapor) outlet 603 of waste heat boiler 6, condensation-water drain 702 is connected with the water inlet 602 of waste heat boiler 6, electrical power output
703 are connected (i.e. by electrical energy transportation caused by steam turbine 7 to burried arc furnace 3) with the electric energy entrance 305 of burried arc furnace 3.
Heat exchanger 8 is provided with low-temperature flue gas entrance 801, combustion air inlet 802, preheated air outlet 803, exhanst gas outlet
804 and condense water out 805.Wherein, low-temperature flue gas entrance 801 is connected with the low-temperature flue gas outlet 604 of waste heat boiler 6, preheats
Air outlet slit 803 is connected with the air intake 502 of combustion chamber 5.
Cooling tower 9, which is provided with, condenses water inlet 901 and coolant outlet 902.Wherein, water inlet 901 and heat exchanger 8 are condensed
Water out 805 is condensed to be connected.
Fluid bed 10 is provided with bamboo charcoal entrance 1001 and gasification gas exit 1002.Wherein, bamboo charcoal entrance 1001 and revolving bed 1
Bamboo charcoal outlet 102 be connected, gasification gas outlet 1002 is connected with the gasification gas entrance 104 of revolving bed 1.
Air compressor machine 11 is provided with gas access 1101 and gas vent 1102.Wherein, the gas of gas vent 1102 and silicon bag 4
Entrance 401 is connected.
Fig. 2 show a kind of method for preparing elementary silicon provided by the invention, comprises the following steps：
Bamboo wood feeding pyrolysis installation is pyrolyzed, obtains bamboo charcoal and pyrolysis oil gas；
Bamboo charcoal is respectively fed to fluidized gasification device and dosing；
Bamboo charcoal is gasified in fluidized gasification device, obtains gasification gas；
Gasification gas is sent into pyrolysis installation, is used to be pyrolyzed bamboo wood as fuel；
Silica, petroleum coke, bituminous coal are sent into dosing, dispensing is carried out with bamboo charcoal, obtains compound；
Feed the mixture into elementary silicon production unit to be reacted, obtain liquid silicon；
Liquid silicon is sent into elementary silicon refinery unit, and is passed through air or oxygen, refinement oxide is carried out and removes in liquid silicon
Aluminium and calcium, obtain ingot casting silicon (i.e. elementary silicon)；
Pyrolysis oil pneumatic transmission is entered in burner to be burnt, obtains high-temperature flue gas；
High-temperature flue gas is sent into steam generation device and exchanged heat with water, obtains steam and low-temperature flue gas；
Steam feeding TRT is generated electricity, obtains electric energy and condensed water.
The moisture content and size of bamboo wood influence the efficiency of pyrolysis, in the preferred embodiment of the invention, the moisture content of bamboo wood
In 10wt% (weight percentage) -15wt% or so, also, bamboo wood is first crushed to before pyrolysis 10mm-100mm block
Shape.
Pyrolysis temperature influences the pyrolysis effect of bamboo wood, and in the preferred embodiment of the invention, the pyrolysis temperature of bamboo wood is 500
DEG C -800 DEG C, at this temperature, the energy consumption of pyrolysis unit can be reduced.When being pyrolyzed using revolving bed 1, when the temperature of pyrolysis
Less than 600 DEG C, the Ω cm of ratio resistance >=2000, when pyrolysis temperature is more than 700 DEG C, the Ω cm of ratio resistance≤10, therefore, to ensure
Bamboo charcoal has higher ratio resistance, and optimal pyrolysis temperature is 600 DEG C -700 DEG C.Revolving bed 1 is oxygen-free environment in pyrolysis, heat
Methane content ＞ 10v/v% (volumn concentration), carbon monoxide content ＞ 30v/v% in pyrolysis oil gas caused by solution, other
Hydro carbons ＞ 10v/v%, calorific value reach 5000kcal/m3More than, it is seen then that pyrolysis oil gas has higher utilization caused by bamboo wood pyrolysis
Value.On pyrolysis installation top, the pyrolysis oil temperature degree of discharge is about 550 DEG C, and without cooling, directly hot sending is into burner
Burnt, substantially increase the heat utilization efficiency of system.
In elementary silicon production process, silica and carbonaceous reducing agent need to be matched, in order to ensure in fusion process not
SiC and SiO occurs2It is remaining, carbon containing very few to cause SiO2React incomplete and carbon containing excessive situations such as causing SiC largely to generate
Occur, need to strictly control the SiO in the C and silica in carbonaceous reducing agent2Molecular proportion is 2.
Carbonaceous reducing agent is selected in addition to investigating the content of fixed carbon and ash content, it is also desirable to have reactivity it is good, than electricity
Resistance is high, graphitization, granularity are not susceptible under high temperature suitably, has certain mechanical strength, the carbonaceous reducing agent that the present invention uses
Including petroleum coke, bituminous coal and bamboo charcoal, the performance of three kinds of carbonaceous reducing agents is shown in Table 1.
Carbonaceous reducing agent Character Comparison in the production of the elementary silicon of table 1
In order to ensure the quality of final obtained elementary silicon, in a preferred embodiment of the invention, petroleum coke, bituminous coal, bamboo charcoal
Weight ratio be (60-70)：(5-10)：(20-40).
Further, in order to obtain the preferable elementary silicon of quality, the composition and granularity of the particle diameter of petroleum coke, bituminous coal and bamboo charcoal
It is required that as shown in table 2.
The carbonaceous reducing agent composition of table 2 and granularity requirements
| Title | Volatile matter/wt% | Ash content/wt% | Fixed carbon/wt% | Granularity/mm |
| Bamboo charcoal | 25-30 | <5 | ＞ 85 | 10-80 |
| Petroleum coke | 12-16 | <0.5 | 82-92 | 1-15 |
| Bituminous coal | <30 | <8 | -- | 1-13 |
SiO in silica2Content is higher, and obtained elementary silicon is better, SiO2Content should be greater than 98%, in the present invention more preferably
In embodiment, SiO in silica used2Content >=99wt%, Fe2O3≤ 0.015wt%, Al2O3≤ 0.03wt%, CaO≤
0.20wt%, P2O5≤ 0.02wt%, MgO≤0.20wt%, remaining≤0.535wt%.In addition, the particle diameter of silica also should not mistake
Big or too small, in the preferred embodiment of the invention, the particle diameter of silica is 8mm-80mm.
High-temperature flue gas is with after water heat exchange, obtaining steam and low-temperature flue gas, and the temperature of low-temperature flue gas is at 300 DEG C or so, at this
In invention preferred embodiment, low-temperature flue gas and combustion air are exchanged heat, obtain preheated air and condensate；Preheated air is sent
Enter in burner, burnt with pyrolysis oil gas；Elementary silicon production unit will be sent into after water cooling will be condensed, for cooling down silicon list
Matter production unit, obtain backwater；Backwater is sent into steam generation device, is exchanged heat with high-temperature flue gas, prepares steam.
Combustion air can be preheating to 200 DEG C or so by low-temperature flue gas, and the temperature of the flue gas finally discharged is less than 100 DEG C, fills
Divide the sensible heat for having reclaimed flue gas.
Through high temperature sintering, its organic principle has been decomposed condensate, and COD contents are almost nil.The temperature of condensate is about 70
DEG C, after cooling, use it for cooling down elementary silicon production unit, not only prevented the generation of sewage, and reduce system
Water requirement, reduce the production cost of elementary silicon.Preferably, condensate can be cooled to about 12 DEG C.From elementary silicon production unit
Return water temperature out is more than 80 DEG C, and steam can be prepared after being exchanged heat with high-temperature flue gas.Whole technique does not have sewage generation.
In technique shown in Fig. 2, electric energy caused by TRT is used to power for elementary silicon production unit.Unnecessary electricity
It is connected to the grid available for industrial park household electricity or according to biomass power generation.When producing elementary silicon using burried arc furnace 3, its
Energy consumption is about 10080 kilowatt hours/ton, and Billy produces the device saving energy 16% of elementary silicon with charcoal.Elementary silicon is in burried arc furnace 3
Inside be in a liquid state discharge, and air or oxygen is passed through in liquid silicon using air compressor machine 11, and refinement oxide can effectively remove elementary silicon
In major impurity aluminium and calcium, and technical process is simple.
It is changed into condensed water after steam-electric power, in the technique shown in Fig. 2, condensed water is admitted to steam generation together with backwater
In device, for preparing steam.
Elementary silicon quality produced by the present invention is good, and preparation process is simple, and silicon burn out rate is low.
Below with reference to specific embodiment, the present invention will be described.Institute's taking technique condition value is in following embodiments
Exemplary, its desirable number range, for especially not dated technological parameter, can refer to often as shown in foregoing summary
Rule technology is carried out.Detection method used in following embodiments is the conventional detection method of the industry.
Embodiment
The present embodiment prepares elementary silicon using the system shown in Fig. 1 and the technological process shown in Fig. 2, specific as follows：
Pyrolysis：Bamboo wood feeding revolving bed 1 is pyrolyzed, obtains bamboo charcoal and pyrolysis oil gas.
Wherein, bamboo wood used is mao bamboon, is broken into 10mm-100mm lump material first, in atmosphere natural air drying
20 days or so, moisture content was down to below 10wt%.
It is anoxybiotic environment in revolving bed 1, the temperature of burner hearth is 700 DEG C, and material pyrolysis temperature is 600 DEG C.
The Industrial Analysis and elementary analysis of obtained bamboo charcoal such as table 3, iodine number：400mg/g-500mg/g, 600 DEG C of pyrolysis temperature
Under degree, ratio resistance is 2155 Ω cm-2356 Ω cm.
The elementary analysis of the bamboo charcoal of table 3 and Industrial Analysis table
Gasification：A part of bamboo charcoal feeding fluid bed 10 is gasified, obtains gasification gas, gained gasification gas calorific value is big
In 2000kcal/m3.It send gasification gas as fuel into revolving bed 1.
Dispensing：Silica, petroleum coke, bituminous coal and a part of bamboo charcoal feeding batch bin 2 are subjected to dispensing, obtain compound.
The SiO of silica2Content is 98.7wt%, particle diameter 8mm-80mm.Petroleum coke：Bamboo charcoal：Bituminous coal=7:5:5；Carbonaceous
The SiO in C and silica in reducing agent2Molecular proportion is 2；Oil, the composition of bamboo charcoal and bituminous coal and granularity requirements are as shown in table 2.
Prepare elementary silicon：Feed the mixture into burried arc furnace 3 to be reacted, obtain liquid silicon；
Liquid silicon is sent into silicon bag 4, and air or oxygen is passed through by air compressor machine 11, refinement oxide is carried out and removes in liquid silicon
Aluminium and calcium, obtain ingot casting silicon.
Bamboo charcoal price 3000 yuan/t, fixed carbon content 85wt%, 2800 yuan/t of charcoal price, fixed carbon content are
70wt%.1 ton of ingot casting silicon consumption 0.5t charcoal of production, in the case where meeting fixed carbon demand, 1 ton of ingot casting silicon of production only consumes
0.4t bamboo charcoals, then can be saved by often producing 1 ton of ingot casting silicon by 200 yuan.
The ingot casting silicon purity of the present embodiment production is 99.99%, has reached the level of chemical grade silicon simple substance, available for organic
The raw material of silicon product.
Generate electricity：Pyrolysis oil pneumatic transmission is entered into combustion chamber 5 to be burnt, obtains high-temperature flue gas；
High-temperature flue gas is sent into waste heat boiler 6 and exchanged heat with water, obtains steam and low-temperature flue gas；
Steam feeding steam turbine 7 is generated electricity, obtains electric energy and condensed water.
The electric energy of acquisition is used to power for burried arc furnace 3.Condensed water is sent into waste heat boiler 6, is changed with high-temperature flue gas
Heat, prepare steam.
The generating efficiency of steam turbine 7 is more than 25%.
Cooling water circulation：Low-temperature flue gas is sent into heat exchanger 8 to exchange heat with combustion air, obtains preheated air and condensate；
Preheated air is sent into combustion chamber 5, burnt with pyrolysis oil gas；
Condensate is sent into cooling tower 9 after cooling down and is sent into burried arc furnace 3, for cooling down burried arc furnace 3, obtain backwater；
Backwater is sent into waste heat boiler 6, is exchanged heat with high-temperature flue gas, prepares steam.
Condensate is cooled to 7 DEG C in cooling tower 9, and backwater is 85 DEG C.
1 ton of elementary silicon is produced, the energy consumption of burried arc furnace is 10080kwh, daily by 50 tons of elementary silicons of production, bamboo wood treating capacity
For 1000 ton days, bamboo wood per ton can generate electricity 500kwh or so, and bamboo wood pyrolysis charcoal yield is 35%, wherein often producing 1 ton of silicon list
Matter, there is 0.5 ton of bamboo charcoal as carbonaceous reducing agent, separately there are 6.5 tons of bamboo charcoals to deliver to fluidized gasification device and gasified.
Whole system realizes that electric energy is self-sustaining, fuel is self-sustaining, and the elementary silicon of output high-quality, has higher economic effect
Benefit.
Obviously, above-described embodiment is only intended to clearly illustrate example of the present invention, and not to embodiment
Limit.For those of ordinary skill in the field, other multi-forms can also be made on the basis of the above description
Change or variation.There is no necessity and possibility to exhaust all the enbodiments.And thus amplify out apparent
Change or change still in protection scope of the present invention among.
Claims (10)
- A kind of 1. system for preparing elementary silicon, it is characterised in that including：Pyrolysis unit, including pyrolysis installation and fluidized gasification device,The pyrolysis installation is provided with bamboo wood entrance, gasification gas entrance, bamboo charcoal outlet and pyrolysis oil gas vent；The fluidized gasification device is provided with bamboo charcoal entrance and gasification gas exit, the bamboo charcoal entrance and the pyrolysis installation Bamboo charcoal outlet is connected, and the gasification gas outlet is connected with the gasification gas entrance of the pyrolysis installation；Dosing, is exported provided with silica entrance, petroleum coke entrance, bituminous coal entrance, bamboo charcoal entrance and compound, and the bamboo charcoal enters Mouth is connected with the bamboo charcoal outlet of the pyrolysis installation；Elementary silicon production unit, exported provided with compound entrance and liquid silicon, the compound entrance and the dosing Compound outlet is connected；Elementary silicon refinery unit, exported provided with gas access, liquid silicon entrance and ingot casting silicon, the liquid-state silicon entrance and the silicon The liquid silicon outlet of simple substance production unit is connected；Generator unit, including burner, steam generation device and TRT；The burner is provided with pyrolysis oil gas entrance, air intake and high-temperature flue gas outlet, the pyrolysis oil gas vent and institute The pyrolysis oil gas vent for stating pyrolysis installation is connected；The steam generation device is provided with high-temperature flue gas entry, water inlet, steam (vapor) outlet and low-temperature flue gas outlet, the high temperature cigarette Gas entrance is connected with the high-temperature flue gas outlet of the burner；The TRT is provided with steam inlet, condensation-water drain and generating set, and the steam inlet produces with the steam The steam (vapor) outlet of device is connected.
- 2. system according to claim 1, it is characterised in that the elementary silicon production unit be additionally provided with cooling water inlet and Backwater exports, and the backwater outlet is connected with the water inlet of the steam generation device；The system also includes cooling water circulation Unit, the cooling water circulation unit include heat-exchanger rig and cooling device；The heat-exchanger rig is provided with low-temperature flue gas entrance, combustion air inlet, preheated air outlet, exhanst gas outlet and condensate and gone out Mouthful, the low-temperature flue gas entrance is connected with the low-temperature flue gas outlet of the steam generation device；The preheated air outlet and institute The air intake for stating burner is connected；The cooling device, which is provided with, condenses water inlet and coolant outlet, the condensation for condensing water inlet and the heat-exchanger rig Water out is connected；The coolant outlet is connected with the cooling water inlet of the elementary silicon production unit.
- 3. system according to claim 1, it is characterised in that the TRT and the elementary silicon production unit phase Even, the electric energy needed for the elementary silicon production unit comes from the TRT.
- 4. system according to claim 1, it is characterised in that the condensation-water drain of the TRT produces with the steam The water inlet of generating apparatus is connected.
- 5. a kind of method that any described system prepares elementary silicon in 1-4 using claim, it is characterised in that including as follows Step：Bamboo wood is sent into the pyrolysis installation to be pyrolyzed, obtains bamboo charcoal and pyrolysis oil gas；The bamboo charcoal is respectively fed to fluidized gasification device and the dosing；The bamboo charcoal is gasified in fluidized gasification device, obtains gasification gas；The gasification gas is sent into the pyrolysis installation, is used to be pyrolyzed the bamboo wood as fuel；Silica, petroleum coke, bituminous coal are sent into the dosing, dispensing is carried out with the bamboo charcoal, obtains compound；The compound is sent into the elementary silicon production unit to be reacted, obtains liquid silicon；The liquid silicon is sent into the elementary silicon refinery unit, and is passed through air or oxygen, is carried out described in refinement oxide removing Aluminium and calcium in liquid silicon, obtain ingot casting silicon；The pyrolysis oil pneumatic transmission is entered in the burner to be burnt, obtains high-temperature flue gas；The high-temperature flue gas is sent into the steam generation device and exchanged heat with water, obtains steam and low-temperature flue gas；The steam is sent into the TRT to be generated electricity, obtains electric energy and condensed water.
- 6. according to the method for claim 5, it is characterised in that also comprise the following steps：The low-temperature flue gas and combustion air are exchanged heat, obtain preheated air and condensate；The preheated air is sent into the burner, burnt with the pyrolysis oil gas；The elementary silicon production unit will be sent into after the condensation water cooling, for cooling down the elementary silicon production unit, obtained Backwater；The backwater is sent into the steam generation device, is exchanged heat with the high-temperature flue gas, prepares the steam.
- 7. according to the method for claim 5, it is characterised in that it is the silicon to be used for electric energy caused by the TRT Simple substance production unit is powered.
- 8. according to the method for claim 5, it is characterised in that the condensed water is sent into the steam generation device and made The standby steam.
- 9. according to the method for claim 5, it is characterised in that the petroleum coke, the bituminous coal, the weight ratio of the bamboo charcoal For (60-70)：(5-10)：(20-40).
- 10. according to the method for claim 5, it is characterised in that the pyrolysis temperature of the bamboo wood is 500 DEG C -800 DEG C.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN114671438A (en) * | 2022-03-31 | 2022-06-28 | 新疆西部合盛硅业有限公司 | Method for automatically controlling oxygen blowing refining by interlocking weight and temperature |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114671438A (en) * | 2022-03-31 | 2022-06-28 | 新疆西部合盛硅业有限公司 | Method for automatically controlling oxygen blowing refining by interlocking weight and temperature |
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