CN115340100A - Method for preparing silicon dioxide by using dust recovered from silicon production - Google Patents
Method for preparing silicon dioxide by using dust recovered from silicon production Download PDFInfo
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- CN115340100A CN115340100A CN202111499567.4A CN202111499567A CN115340100A CN 115340100 A CN115340100 A CN 115340100A CN 202111499567 A CN202111499567 A CN 202111499567A CN 115340100 A CN115340100 A CN 115340100A
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/113—Silicon oxides; Hydrates thereof
- C01B33/12—Silica; Hydrates thereof, e.g. lepidoic silicic acid
- C01B33/18—Preparation of finely divided silica neither in sol nor in gel form; After-treatment thereof
- C01B33/181—Preparation of finely divided silica neither in sol nor in gel form; After-treatment thereof by a dry process
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/01—Particle morphology depicted by an image
- C01P2004/03—Particle morphology depicted by an image obtained by SEM
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/12—Surface area
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Abstract
The invention relates to the technical field of C01B chemical production, and particularly provides a method for preparing silicon dioxide by using dust recovered in silicon production. A method for preparing silicon dioxide by using dust recycled from silicon production comprises the following steps: (1) preparation of dust: preparing dust obtained by silicon production and recovery; (2) high-temperature preparation of silica: and putting the prepared dust into a high-temperature furnace, then inputting oxygen into the high-temperature furnace, and carrying out high-temperature oxidation on the dust in the high-temperature furnace to obtain silicon dioxide. The method uses the waste material produced by silicon as the raw material, has the characteristic of environmental protection, really realizes the recycling of the raw material and the product, has complete gas-solid reaction in the preparation process, does not need to add some extra liquid phase components, and effectively avoids the corrosion of equipment and the post-treatment problem of waste liquid.
Description
Technical Field
The invention relates to the technical field of C01B chemical production, and particularly provides a method for preparing silicon dioxide by using dust recovered in silicon production.
Technical Field
Silica is a non-toxic, light, porous, fine powder, has good dispersibility, and is widely used in the fields of rubber, organosilicon materials, adhesives, papermaking, medicine and the like.
The prior art for preparing silica usually uses chemical synthesis methods, but the methods are poor in environmental protection, so that some researches usually use some recycled dust or liquid to prepare silica. Patent CN103342366A provides a method for purifying silica from hot residue of industrial glue, but the reaction requires the use of acid to treat the residue, and these acids not only generate a large amount of waste acid liquid, but also may affect the surface properties of silica during calcination, so that when silica is used in glass glue, the surface of glass glue is easily sticky; patent CN111252779B uses electromagnetic waves to react oxygen with dust suspended in oxygen to obtain silica, but the silica is prepared in the form of spheres with a relatively single particle size, and cannot be used in glass cement well due to the limited amount of the silica added.
Disclosure of Invention
In order to solve the above technical problems, a first aspect of the present invention provides a method for preparing silica using dust recovered from silicon production, comprising the steps of:
(1) Preparation of dust: preparing dust obtained by silicon production and recovery;
(2) Preparing silicon dioxide at high temperature: and (3) putting the prepared dust into a high-temperature furnace, then inputting oxygen into the high-temperature furnace, and oxidizing the dust at high temperature in the high-temperature furnace to obtain silicon dioxide.
For step (1)
In the production process of the silicon powder, the silicon powder is prepared by reducing silicon dioxide with carbon at 870-1728 ℃ under the high temperature condition. Under the condition of 1500-1710 ℃, the silicon dioxide is easy to evaporate to form SiO, dust such as SiO, carbon powder, silicon powder and the like is obtained in the dust recovery device, the silicon dioxide is prepared by utilizing the dust obtained by silicon production recovery, and the process takes the waste material of silicon production as the raw material and has the characteristic of environmental protection.
For step (2)
Preferably, the high-temperature oxidation is three-stage heating; the temperature of the first-stage high-temperature oxidation is 100-400 ℃ (preferably 200-300 ℃, and more preferably 250 ℃); the temperature of the second-stage high-temperature oxidation is 500-800 ℃ (preferably 650-750 ℃, and more preferably 700 ℃); the temperature of the third-stage high-temperature oxidation is 900-1300 ℃ (preferably 1100-1250 ℃, and more preferably 1200 ℃)
The inventors have found that the higher purity of the silica produced using the particular three-stage temperature increase in the system of the present invention may be due to the fact that some of the competing relationships of the oxidation and reduction reactions in the system can be effectively controlled during the reaction, making the oxidation reactions more likely to occur.
Meanwhile, the silicon dioxide with higher purity can be obtained by controlling three-stage reaction, and the application performance of the silicon dioxide is better, probably because the silicon dioxide is not subjected to reduction reaction with carbon in the first stage when the temperature is lower, but is better subjected to full oxidation with oxygen, so that the silicon dioxide can be fully formed, and the carbon can be fully oxidized into carbon dioxide instead of carbon monoxide in the second stage, so that the reduction reaction in a high-temperature furnace is reduced; at the reaction temperature of the third stage, the defect that silicon can not be fully reacted due to the deposition of silicon dioxide can be effectively avoided; meanwhile, in the second stage, because the dust contains carbon dust which has a porous structure, the carbon dust can be easily adsorbed and reacted with oxygen, the reduction reaction of silicon dioxide can be effectively avoided, and the purity of the silicon dioxide is effectively increased.
Preferably, the temperature increase rate is 20 to 50 ℃/min (preferably 30 to 45 ℃/min, more preferably 35 ℃/min). The temperature rise rate in the present invention refers to a rate of raising the temperature from room temperature to the temperature of the first-stage high-temperature oxidation, a rate of raising the temperature from the temperature of the first-stage high-temperature oxidation to the temperature of the second-stage high-temperature oxidation, and a rate of raising the temperature from the temperature of the second-stage high-temperature oxidation to the temperature of the third-stage high-temperature oxidation.
Preferably, the residence reaction time of the first-stage high-temperature oxidation is 30-70 min (preferably 40-60 min; further preferably 50 min); the residence reaction time of the second-stage high-temperature oxidation is 20-60 min (preferably 30-50 min); the residence reaction time of the third-stage high-temperature oxidation is 60-120 min (preferably 70-90 min); here, the residence time means the time from reaching the reaction temperature.
Through extensive research and development experiments, it is found that the reaction time needs to be strictly controlled, and the forward progress of the oxidation reaction can be influenced by too long or too short reaction time.
The pressure of the oxygen gas fed is preferably 0.5 to 2MPa (preferably 0.8 to 1.2MPa; more preferably 1 MPa). Wherein the pressure of the input oxygen refers to the pressure at which the amount of the input oxygen is such that the high temperature furnace reaches.
Preferably, the concentration of dust suspended in oxygen is greater than 0.5g/m 3 (ii) a It is further preferred that the concentration of the dust suspended in oxygen is 60 to 80g/m 3 (preferably 70 g/m) 3 )。
In the prior art, in order to enable the oxidation reaction to be fully generated, an extremely excessive amount of oxygen is often used, but researches show that the higher the pressure of oxygen is, the better the system of the invention is, when the pressure of oxygen is too high, the performance of the prepared silica is not so good, probably because the oxygen content is too high and the pressure in the system is too large, some reactions with increased volume are easier to reversely perform, so that the silica is easier to be reduced, meanwhile, in the process of reacting silicon monoxide and carbon to generate silicon and carbon dioxide, the pressure has less influence on the reactions, and the reactions can be continuously performed.
A second aspect of the present invention provides a silica prepared by any one of the above-described methods for preparing silica using dust recovered from silicon production.
In a third aspect, the present invention provides the use of silica as a filler for polymers, such as polymer paint, polymer adhesive, polymer glass cement, etc.
Compared with the prior art, the invention at least comprises the following beneficial effects:
1. the invention uses the waste material produced by silicon as the raw material, has the characteristic of environmental protection, really realizes the recycling between the raw material and the product, has complete gas-solid reaction in the preparation process, does not need to add some extra liquid phase components, and effectively avoids the corrosion of equipment and the post-treatment problem of waste liquid.
2. In the prior art, when elemental silicon is used for high-temperature sintering, crushing, ball milling, acid washing, water washing and dehydration are needed, then high-temperature melting is carried out, and finally oxidation reaction is carried out, the process flow is complicated, a large amount of waste acid is generated, and during the oxidation process, gas generated by some acidic impurities possibly influences a reaction system.
3. In the prior art, templates such as surfactants are used for promoting the growth of silicon dioxide when the recycled micro silicon powder is used for preparing the silicon dioxide, but the dispersibility of the surfactants to the silicon dioxide is difficult to control.
4. Because the invention does not use some templates to control the particle size of the silica, the inventor unexpectedly finds in experiments that the specific three-stage high-temperature oxidation mode is arranged in the invention, so that the oxidation reaction in the system can be better promoted, the silicon monoxide and the silicon powder can be fully used for generating the silica, and the reduction reaction of the silica can be prevented, thus the prepared silica can be effectively generated and has higher purity.
5. By controlling the pressure of the oxygen, the forward reaction can be better promoted, so that the reaction rate and the purity of the silicon dioxide are better improved.
Drawings
FIG. 1 is a scanning electron micrograph of the silica prepared in example 1;
FIG. 2 is a scanning electron micrograph of silica prepared according to example 2;
FIG. 3 is a scanning electron micrograph of the silica prepared in example 3.
Detailed Description
The specific surface area of the silica in the examples was measured using an Autosorb IQ-XR full-automatic specific surface and porosity analyzer, congta instruments, USA.
Example 1
A first aspect of the present embodiment provides a method for preparing silica using dust recovered from silicon production, comprising the steps of:
(1) Preparation of dust: preparing dust obtained by silicon production and recovery;
(2) Preparing silicon dioxide at high temperature: the prepared dust was put into a high-temperature furnace, and then oxygen (the pressure of the input oxygen was 0.8MPa, and the concentration of the dust suspended in the oxygen was 60 g/m) was fed into the high-temperature furnace 3 ) Then heating to 200 ℃ at the speed of 30 ℃/min, carrying out high-temperature oxidation reaction at 200 ℃ for 40min, heating to 650 ℃ at the speed of 30 ℃/min, carrying out high-temperature oxidation reaction at 650 ℃ for 30min, heating to 1100 ℃ at the speed of 30 ℃/min, and carrying out high-temperature oxidation reaction at 1100 ℃ for 70min to obtain the silicon dioxide.
FIG. 1 is a scanning electron micrograph of the silica prepared;
the specific surface area of the silicon dioxide obtained by the test is 80.2m 2 /g。
Example 2
A first aspect of the present embodiment provides a method for preparing silica using recovered dust from silicon production, comprising the steps of:
(1) Preparation of dust: preparing dust obtained by silicon production and recovery;
(2) Preparing silicon dioxide at high temperature: the prepared dust was put into a high-temperature furnace, and then oxygen (the pressure of the input oxygen was 1.2MPa, and the concentration of the dust suspended in the oxygen was 80 g/m) was fed into the high-temperature furnace 3 ) Then heating to 300 ℃ at the speed of 40 ℃/min, carrying out high-temperature oxidation reaction at 300 ℃ for 60min, heating to 750 ℃ at the speed of 40 ℃/min, carrying out high-temperature oxidation reaction at 750 ℃ for 40min, heating to 1250 ℃ at the speed of 40 ℃/min, and carrying out high-temperature oxidation reaction at 1250 ℃ for 80min to obtain the silicon dioxide.
FIG. 2 is a scanning electron micrograph of the silica prepared;
the specific surface area of the silicon dioxide obtained by the test is 100.6m 2 /g。
Example 3
A first aspect of the present embodiment provides a method for preparing silica using dust recovered from silicon production, comprising the steps of:
(1) Preparation of dust: preparing dust obtained by silicon production and recovery;
(2) Preparing silicon dioxide at high temperature: the prepared dust was put into a high-temperature furnace, and then oxygen (the pressure of the input oxygen was 1MPa, and the concentration of the dust suspended in the oxygen was 70 g/m) was fed into the high-temperature furnace 3 ) Then heating to 250 ℃ at the speed of 35 ℃/min, carrying out high-temperature oxidation reaction at 250 ℃ for 50min, heating to 700 ℃ at the speed of 35 ℃/min, carrying out high-temperature oxidation reaction at 700 ℃ for 40min, heating to 1200 ℃ at the speed of 35 ℃/min, and carrying out high-temperature oxidation reaction at 1200 ℃ for 80min to obtain the silicon dioxide.
FIG. 3 is a scanning electron micrograph of the prepared silica;
the specific surface area of the silicon dioxide obtained by the test is 70.5m 2 /g。
Example 4
A first aspect of the present embodiment provides a method for preparing silica using recovered dust from silicon production, comprising the steps of:
(1) Preparation of dust: preparing dust obtained by silicon production and recovery;
(2) Preparing silicon dioxide at high temperature: the prepared dust was put into a high-temperature furnace, and oxygen (the pressure of the oxygen input was 1MPa, and the concentration of the dust suspended in oxygen was 70 g/m) was fed into the high-temperature furnace 3 ) Then raising the temperature to 1000 ℃ at the speed of 35 ℃/min, and carrying out high-temperature oxidation reaction at 1000 ℃ for 170min to obtain the silicon dioxide.
A first aspect of this example provides a silica prepared by the above method.
Example 5
A first aspect of the present embodiment provides a method for preparing silica using dust recovered from silicon production, comprising the steps of:
(1) Preparation of dust: preparing dust obtained by silicon production and recovery;
(2) Preparing silicon dioxide at high temperature: the prepared dust was put into a high-temperature furnace, and then oxygen (the pressure of the input oxygen was 5MPa, and the concentration of the dust suspended in the oxygen was 70 g/m) was fed into the high-temperature furnace 3 ) Then raising the temperature to 1000 ℃ at the speed of 35 ℃/min, and carrying out high-temperature oxidation reaction at 1000 ℃ for 300min to obtain the silicon dioxide.
A first aspect of this embodiment provides a silica prepared by the above method.
Performance test
The performance of the glass paste was measured by adding silica to glass paste of the same formulation (the formulation of the glass paste comprises 107 paste, dimethyl silicone oil, methyl mixed ketoxime type crosslinking agent, dibutyltin dilaurate, silane coupling agent, silica, prepared by mechanical stirring and mixing under vacuum) and then testing the performance, the results of which are shown in table 1:
TABLE 1
Claims (10)
1. A method for preparing silicon dioxide by using dust recovered from silicon production is characterized by comprising the following steps:
(1) Preparation of dust: preparing dust obtained by silicon production and recovery;
(2) Preparing silicon dioxide at high temperature: and (3) putting the prepared dust into a high-temperature furnace, then inputting oxygen into the high-temperature furnace, and oxidizing the dust at high temperature in the high-temperature furnace to obtain silicon dioxide.
2. The method for preparing silicon dioxide by using the dust recycled from the silicon production as claimed in claim 1, wherein the high-temperature oxidation is a three-stage temperature rise; the temperature of the first-stage high-temperature oxidation is 100-400 ℃; the temperature of the second-stage high-temperature oxidation is 500-800 ℃; the temperature of the third section high temperature oxidation is 900-1300 ℃.
3. The method for preparing silica using dust recovered from silicon production according to claim 2, wherein the temperature rising rate is 20 to 50 ℃/min.
4. The method for preparing silica by using the dust recovered from the silicon production according to claim 2 or 3, wherein the residence reaction time of the first stage high temperature oxidation is 30 to 70min.
5. The method for preparing silicon dioxide by using the dust recycled from the silicon production as claimed in claim 4, wherein the residence reaction time of the second stage high temperature oxidation is 20-60 min.
6. The method for preparing silicon dioxide by using the dust recovered from the silicon production as claimed in claim 5, wherein the residence time of the third stage high temperature oxidation is 60-120 min.
7. The method for preparing silica using dust recovered from silicon production according to claim 4, wherein the pressure of the input oxygen is 0.5 to 2MPa.
8. A method for producing silica from silicon production recovery dust according to claim 1, characterized in that the concentration of dust suspended in oxygen is more than 0.5g/m 3 。
9. Silica produced by a process for producing silica from silicon production recycle dust according to any one of claims 1 to 8.
10. Use of a silica according to claim 9 in a glass cement.
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Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001354409A (en) * | 2000-06-07 | 2001-12-25 | Denki Kagaku Kogyo Kk | Method for manufacturing ultrafine powder silica |
| JP2006312583A (en) * | 2006-07-18 | 2006-11-16 | Denki Kagaku Kogyo Kk | Manufacturing method of superfine powder silica |
| WO2012153897A1 (en) * | 2011-05-12 | 2012-11-15 | 충남대학교 산학협력단 | Method for producing high-purity porous silica and silicon derived from rice husks |
| US20140030525A1 (en) * | 2011-04-27 | 2014-01-30 | Evonik Degussa Gmbh | Silicon dioxide powder having large pore length |
| CN109319800A (en) * | 2017-07-31 | 2019-02-12 | 李桂玉 | A kind of method that high-salt wastewater sulfating roasting two-step method prepares silicate |
| JP2020040861A (en) * | 2018-09-12 | 2020-03-19 | 株式会社クボタ | Method and apparatus for producing amorphous silica |
| CN111252779A (en) * | 2020-04-08 | 2020-06-09 | 汤姆逊新材料科技(嘉兴)有限公司 | Preparation method of spherical nano silicon dioxide |
| CN111268685A (en) * | 2020-03-09 | 2020-06-12 | 邓咏兰 | Synthesis process of fumed silica |
| CN111732108A (en) * | 2020-06-12 | 2020-10-02 | 安徽壹石通材料科技股份有限公司 | Porous amorphous silicon dioxide powder and preparation method and application thereof |
| CN212915406U (en) * | 2020-05-22 | 2021-04-09 | 福建创威新材料科技有限公司 | Mixing apparatus is used in fumed silica production |
-
2021
- 2021-12-09 CN CN202111499567.4A patent/CN115340100B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001354409A (en) * | 2000-06-07 | 2001-12-25 | Denki Kagaku Kogyo Kk | Method for manufacturing ultrafine powder silica |
| JP2006312583A (en) * | 2006-07-18 | 2006-11-16 | Denki Kagaku Kogyo Kk | Manufacturing method of superfine powder silica |
| US20140030525A1 (en) * | 2011-04-27 | 2014-01-30 | Evonik Degussa Gmbh | Silicon dioxide powder having large pore length |
| WO2012153897A1 (en) * | 2011-05-12 | 2012-11-15 | 충남대학교 산학협력단 | Method for producing high-purity porous silica and silicon derived from rice husks |
| CN109319800A (en) * | 2017-07-31 | 2019-02-12 | 李桂玉 | A kind of method that high-salt wastewater sulfating roasting two-step method prepares silicate |
| JP2020040861A (en) * | 2018-09-12 | 2020-03-19 | 株式会社クボタ | Method and apparatus for producing amorphous silica |
| CN111268685A (en) * | 2020-03-09 | 2020-06-12 | 邓咏兰 | Synthesis process of fumed silica |
| CN111252779A (en) * | 2020-04-08 | 2020-06-09 | 汤姆逊新材料科技(嘉兴)有限公司 | Preparation method of spherical nano silicon dioxide |
| CN212915406U (en) * | 2020-05-22 | 2021-04-09 | 福建创威新材料科技有限公司 | Mixing apparatus is used in fumed silica production |
| CN111732108A (en) * | 2020-06-12 | 2020-10-02 | 安徽壹石通材料科技股份有限公司 | Porous amorphous silicon dioxide powder and preparation method and application thereof |
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