CN102398906B - Method for producing SiF4 from Na2SiF6 through pyrolysis - Google Patents
Method for producing SiF4 from Na2SiF6 through pyrolysis Download PDFInfo
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- CN102398906B CN102398906B CN201110207003.9A CN201110207003A CN102398906B CN 102398906 B CN102398906 B CN 102398906B CN 201110207003 A CN201110207003 A CN 201110207003A CN 102398906 B CN102398906 B CN 102398906B
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Abstract
The invention discloses a method for producing SiF4 from a phosphorus fertilizer industry by-product Na2SiF6 through pyrolysis. The method comprises steps that: Na2SiF6 is dried in a vacuum dryer, and is delivered into a fixed-quantity feeder through a material guiding groove; Na2SiF6 is mixed with NaF in the fixed-quantity feeder, and the mixture is delivered into a high-temperature reaction vessel or a high-temperature circulating fluidized bed; the mixture is subject to pyrolysis for 1-3 hours under a temperature of 600-750 DEG C, wherein the pressure in the high-temperature reaction vessel or the high-temperature circulating fluidized bed is controlled at 10-50mmH2O, such that NaF and SiF4 gases are produced through pyrolysis; NaF is delivered back into the fixed-quantity feeder and is reused; the SiF4 gas is condensed in a condenser, processed though a dust-removing treatment, and purified by using two stages of activated carbon adsorbing columns; the SiF4 gas is then processed through refrigeration compression; the SiF4 gas is delivered into a cylinder, and is stored in the cylinder. The production method provided by the invention is advantaged in low production cost. No waste is generated during the production process, such that clean production is realized. The quality of the produced silicon tetrafluoride gas is stable, and the purity of the silicon tetrafluoride gas reaches 99.9%.
Description
Technical field
The present invention relates to technical field of fluorine chemical industry, be specifically related to a kind of Na
2siF
6siF is produced in pyrolysis
4method.
Background technology
SiF
4be the important source material in electronics processing industry, be widely used in semi-conductor and field fiber.In semicon industry, SiF
4be mainly used in the etching agent of silicon nitride, tantalum silicide etc., P-type dopant, epitaxial deposition diffuse si source etc., can also for the preparation of electronic-grade silane and polysilicon.In addition, SiF
4also be used as the raw materials for production and production material for building etc. of photoconductive fiber pure quartz glass.Along with SiF
4for the exploitation of the polysilicon production process of intermediate product is with ripe, SiF
4wide application prospect will be shown at semicon industry.Current SiF
4production method mainly contain two kinds, namely traditional sulfuric acid process and Si-HF direct synthesis technique.All there is following shortcoming in these two kinds of production methods: production cost is high, the low conversion rate from starting material to silicon tetrafluoride, and by product is more, and impurity is difficult to remove.Develop that a kind of abundant raw materials, production cost are low, the production SiF of environment-protecting clean
4method be current urgent problem.
Summary of the invention
The object of the present invention is to provide a kind of Na
2siF
6siF is produced in pyrolysis
4method.
In order to realize above object, the technical solution adopted in the present invention is: a kind of Na
2siF
6siF is produced in pyrolysis
4method, comprise the following steps:
(1) by Phosphate Fertilizer Industry by product Na
2siF
6vacuum drier is sent into, Na through feeder
2siF
6in 200 ~ 350 DEG C of vacuum-dryings 1 ~ 3 hour in vacuum drier;
(2) enter doser by deflector chute after vacuum-drying, in doser with NaF by weight being Na
2siF
6: NaF=10:(1 ~ 5) mix rear feeding pyroreaction still or high-temp recirculating fluidized bed, 600 ~ 750 DEG C of pyrolysis 1 ~ 3 hour, pyroreaction still or high-temp recirculating fluidized bed internal pressure controlled to be 10 ~ 50mmH
2o, pyrolysis produces NaF and SiF
4gas;
(3) NaF that pyrolysis produces returns doser and uses, the SiF that pyrolysis produces
4gas is derived by dry vacuum pump, enters condenser condenses, and then removes Na through fly-ash separator
2siF
6micro mist, afterwards successively through primary activity charcoal adsorption column and second order activity charcoal adsorption column two-step purification, and then under-80 ~-30 DEG C of temperature condition after the freezing compression of 2 ~ 5MPa, imports the steel cylinder storage that pressure is 2 ~ 5MPa.
Further, the filler of primary activity charcoal adsorption column is under vacuum in 115 ~ 200 DEG C of activation gac of 2 ~ 4 hours.The filler of second order activity charcoal adsorption column is under vacuum in 300 ~ 500 DEG C of activation gac of 2 ~ 4 hours.
Na provided by the invention
2siF
6siF is produced in pyrolysis
4method adopt raw material Na
2siF
6it is Phosphate Fertilizer Industry by product.The Na of current Phosphate Fertilizer Industry by-product
2siF
6purposes is little, and added value is low, is therefore all that heap abandons process mostly, not only pollutes environment, but also cause the significant wastage of fluorine resource.The present invention utilizes Phosphate Fertilizer Industry by product Na
2siF
6produce silicon tetrafluoride, solve Na on the one hand
2siF
6random heap abandons the problem of environmental pollution and fluorine problem of resource waste that cause, also has abundant raw material source, cheap advantage on the other hand.SiF provided by the invention
4production method production cost low, also produce without any waste in process of production, accomplished real cleaner production, the steady quality of obtained silicon tetrafluoride gas product, purity all can reach 99.9%.Na provided by the invention
2siF
6siF is produced in pyrolysis
4method added value high, be applicable to applying.
Embodiment
Embodiment 1
The present embodiment SiF
4production method, step is as follows:
(1) Phosphate Fertilizer Industry by product Na is got
2siF
6about 3kg, sends into vacuum tray dryer through feeder, Na
2siF
6in 200 DEG C of vacuum-dryings 3 hours in vacuum tray dryer, the vacuum pressure in vacuum tray dryer controls at-0.095MPa;
(2) Na
2siF
6doser is entered by deflector chute, Na in doser after vacuum drying treatment
2siF
6with NaF by weight being Na
2siF
6: NaF=10:1 mixes, and sends into high-temp recirculating fluidized bed afterwards, and 750 DEG C of pyrolysis 1 hour, high-temp recirculating fluidized bed internal pressure controlled as 10mmH
2o, pyrolysis produces NaF and SiF
4gas;
(3) NaF that pyrolysis produces returns doser recycling, the SiF that pyrolysis produces after cooling
4gas is derived by dry vacuum pump, enters condenser condenses, and then removes Na through fly-ash separator
2siF
6micro mist, afterwards successively through primary activity charcoal adsorption column and second order activity charcoal adsorption column two-step purification, the filler of primary activity charcoal adsorption column is under vacuum in 115 DEG C of activation gac of 4 hours, the filler of second order activity charcoal adsorption column is under vacuum in 300 DEG C of activation gac of 4 hours, and then in-80 DEG C, under 2.5Mpa pressure condition after freezing compression, importing pressure is that the steel cylinder of 2.5MPa stores.The SiF that the present embodiment is obtained
4the purity of gas products is 99.91%.
Embodiment 2
The present embodiment SiF
4production method, step is as follows:
(1) Phosphate Fertilizer Industry by product Na is got
2siF
6about 3.5kg, sends into vacuum target formula moisture eliminator through feeder, Na
2siF
6in 300 DEG C of vacuum-dryings 2.5 hours in vacuum target formula moisture eliminator, the vacuum pressure in vacuum target formula moisture eliminator controls at-0.095MPa;
(2) Na
2siF
6doser is entered by deflector chute, Na in doser after vacuum drying treatment
2siF
6with NaF by weight being Na
2siF
6: NaF=10:3 mixes, and sends into high-temp recirculating fluidized bed afterwards, and 700 DEG C of pyrolysis 2 hours, high-temp recirculating fluidized bed internal pressure controlled as 30mmH
2o, pyrolysis produces NaF and SiF
4gas;
(3) NaF that pyrolysis produces returns doser recycling, the SiF that pyrolysis produces after cooling
4gas is derived by dry vacuum pump, enters condenser condenses, and then removes Na through fly-ash separator
2siF
6micro mist, afterwards successively through primary activity charcoal adsorption column and second order activity charcoal adsorption column two-step purification, the filler of primary activity charcoal adsorption column is under vacuum in 120 DEG C of activation gac of 4 hours, the filler of second order activity charcoal adsorption column is under vacuum in 400 DEG C of activation gac of 4 hours, and then in-60 DEG C, under 2.5Mpa pressure condition after freezing compression, importing pressure is that the steel cylinder of 2.5MPa stores.The SiF that the present embodiment is obtained
4the purity of gas products is 99.90%.
Embodiment 3
The present embodiment SiF
4production method, step is as follows:
(1) Phosphate Fertilizer Industry by product Na is got
2siF
6about 3kg, sends into vacuum target formula moisture eliminator through feeder, Na
2siF
6in 350 DEG C of vacuum-dryings 1 hour in vacuum target formula moisture eliminator, the vacuum pressure in vacuum target formula moisture eliminator controls at-0.095MPa;
(2) Na
2siF
6doser is entered by deflector chute, Na in doser after vacuum drying treatment
2siF
6with NaF by weight being Na
2siF
6: NaF=10:5 mixes, and sends into pyroreaction still afterwards, and 600 DEG C of pyrolysis 3 hours, pyroreaction still internal pressure controlled as 50mmH
2o, pyrolysis produces NaF and SiF
4gas;
(3) NaF that pyrolysis produces returns doser recycling, the SiF that pyrolysis produces after cooling
4gas is derived by dry vacuum pump, enters condenser condenses, and then removes Na through fly-ash separator
2siF
6micro mist, afterwards successively through primary activity charcoal adsorption column and second order activity charcoal adsorption column two-step purification, the filler of primary activity charcoal adsorption column is under vacuum in 200 DEG C of activation gac of 2 hours, the filler of second order activity charcoal adsorption column is under vacuum in 500 DEG C of activation gac of 2 hours, and then in-30 DEG C, under 5Mpa pressure condition after freezing compression, importing pressure is that the steel cylinder of 5MPa stores.The SiF that the present embodiment is obtained
4the purity of gas products is 99.93%.
Embodiment 4
The present embodiment SiF
4production method, step is as follows:
(1) Phosphate Fertilizer Industry by product Na is got
2siF
6about 3kg, sends into vacuum tray dryer through feeder, Na
2siF
6in 200 DEG C of vacuum-dryings 3 hours in vacuum tray dryer, the vacuum pressure in vacuum tray dryer controls at-0.095MPa;
(2) Na
2siF
6doser is entered by deflector chute, Na in doser after vacuum drying treatment
2siF
6with NaF by weight being Na
2siF
6: NaF=10:3 mixes, and sends into pyroreaction still afterwards, and 700 DEG C of pyrolysis 2 hours, pyroreaction still internal pressure controlled as 10mmH
2o, pyrolysis produces NaF and SiF
4gas;
(3) NaF that pyrolysis produces returns doser recycling, the SiF that pyrolysis produces after cooling
4gas is derived by dry vacuum pump, enters condenser condenses, and then removes Na through fly-ash separator
2siF
6micro mist, afterwards successively through primary activity charcoal adsorption column and second order activity charcoal adsorption column two-step purification, the filler of primary activity charcoal adsorption column is under vacuum in 200 DEG C of activation gac of 2 hours, the filler of second order activity charcoal adsorption column is under vacuum in 500 DEG C of activation gac of 2 hours, and then in-60 DEG C, under 2Mpa pressure condition after freezing compression, importing pressure is that the steel cylinder of 2MPa stores.The SiF that the present embodiment is obtained
4the purity of gas products is 99.91%.
Claims (3)
1. a Na
2siF
6siF is produced in pyrolysis
4method, it is characterized in that, comprise the following steps:
(1) Phosphate Fertilizer Industry by product Na
2siF
6vacuum drier is sent into, Na through feeder
2siF
6in 200 ~ 350 DEG C of vacuum-dryings 1 ~ 3 hour in vacuum drier;
(2) send into doser by deflector chute after vacuum-drying, in doser with NaF by weight being Na
2siF
6: NaF=10:(1 ~ 5) mix rear feeding pyroreaction still or high-temp recirculating fluidized bed, 600 ~ 750 DEG C of pyrolysis 1 ~ 3 hour, pyroreaction still or high-temp recirculating fluidized bed internal pressure controlled to be 10 ~ 50mmH
2o, pyrolysis produces NaF and SiF
4gas;
(3) NaF that pyrolysis produces returns doser and uses, the SiF that pyrolysis produces
4gas is derived by dry vacuum pump, enters condenser condenses, and then removes Na through fly-ash separator
2siF
6micro mist, afterwards successively through primary activity charcoal adsorption column and second order activity charcoal adsorption column two-step purification, and then under-80 ~-30 DEG C of temperature condition after the freezing compression of 2 ~ 5MPa, imports the steel cylinder storage that pressure is 2 ~ 5MPa.
2. Na according to claim 1
2siF
6siF is produced in pyrolysis
4method, it is characterized in that, the filler of described primary activity charcoal adsorption column is under vacuum in 115 ~ 200 DEG C of activation gac of 2 ~ 4 hours.
3. Na according to claim 1
2siF
6siF is produced in pyrolysis
4method, it is characterized in that, the filler of described second order activity charcoal adsorption column is under vacuum in 300 ~ 500 DEG C of activation gac of 2 ~ 4 hours.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110207003.9A CN102398906B (en) | 2011-07-22 | 2011-07-22 | Method for producing SiF4 from Na2SiF6 through pyrolysis |
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|---|---|---|---|
| CN201110207003.9A CN102398906B (en) | 2011-07-22 | 2011-07-22 | Method for producing SiF4 from Na2SiF6 through pyrolysis |
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| CN102398906B true CN102398906B (en) | 2014-12-17 |
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Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102701215A (en) * | 2012-05-10 | 2012-10-03 | 多氟多化工股份有限公司 | Method for preparing silicon tetrafluoride co-production with calcium fluoride by using fluosilicic acid and calcium carbide dust |
| CN102897769B (en) * | 2012-08-24 | 2014-10-29 | 山东瑞福锂业有限公司 | Production technology of silicon tetrafluoride |
| CN104498062B (en) * | 2014-09-01 | 2015-11-11 | 湖南启天环保科技有限公司 | A kind of vacuum pyrolysis technology |
| CN104843713B (en) * | 2015-06-04 | 2016-10-12 | 贵州省产品质量监督检验院 | A kind of pyrolytic prodan prepares method and the device thereof of Silicon fluoride. |
| CN110683548B (en) * | 2018-07-04 | 2021-08-17 | 中国科学院过程工程研究所 | Method for efficiently producing silicon tetrafluoride and sodium fluoride by using sodium fluosilicate |
| CN111039293B (en) * | 2018-10-15 | 2021-06-29 | 多氟多化工股份有限公司 | Production method of silicon tetrafluoride |
| CN110606490B (en) * | 2019-06-20 | 2022-09-09 | 绿菱电子材料（天津）有限公司 | Synthesis and purification method of high-purity silicon tetrafluoride |
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|---|---|---|---|---|
| CN101698482A (en) * | 2009-10-13 | 2010-04-28 | 西安三瑞实业有限公司 | Method for preparing silicon tetrafluoride through pyrolysis of sodium fluosilicate in rotary reaction furnace |
| CN101774588A (en) * | 2010-02-11 | 2010-07-14 | 浙江中宁硅业有限公司 | Purification method of silicon tetrafluoride prepared by using fluoride and silicon source power as raw materials |
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|---|---|---|---|---|
| JPS604126B2 (en) * | 1981-03-18 | 1985-02-01 | セントラル硝子株式会社 | Purification method of silicon tetrafluoride |
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|---|---|---|---|---|
| CN101698482A (en) * | 2009-10-13 | 2010-04-28 | 西安三瑞实业有限公司 | Method for preparing silicon tetrafluoride through pyrolysis of sodium fluosilicate in rotary reaction furnace |
| CN101774588A (en) * | 2010-02-11 | 2010-07-14 | 浙江中宁硅业有限公司 | Purification method of silicon tetrafluoride prepared by using fluoride and silicon source power as raw materials |
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Effective date of registration: 20200922 Address after: No.1 Jiaoke Road, Xuheng street, zhongzhan District, Jiaozuo City, Henan Province Patentee after: Henan fluorine based new material technology Co.,Ltd. Address before: 454191, Feng County, Henan Province, Jiaozuo Feng Feng Chemical Industry Zone Patentee before: DO-FLUORIDE CHEMICALS Co.,Ltd. |