CN102633266A - Preparation method of nano SiO2 - Google Patents

Preparation method of nano SiO2 Download PDF

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Publication number
CN102633266A
CN102633266A CN2012101218438A CN201210121843A CN102633266A CN 102633266 A CN102633266 A CN 102633266A CN 2012101218438 A CN2012101218438 A CN 2012101218438A CN 201210121843 A CN201210121843 A CN 201210121843A CN 102633266 A CN102633266 A CN 102633266A
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preparation
hco
nano silicon
reaction
mhco
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章浩龙
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ZHEJIANG YUDA CHEMICAL INDUSTRY Co Ltd
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ZHEJIANG YUDA CHEMICAL INDUSTRY Co Ltd
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
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  • Silicates, Zeolites, And Molecular Sieves (AREA)

Abstract

The invention discloses a preparation method of nano SiO2. The preparation method is characterized by taking soluble silicate M2O.nSiO2 and NH4HCO3 as raw materials to react to obtain hydrate SiO2 through precipitation, separating out filtrate through filtration, then washing the filter cake, displacing the filter cake with an organic solvent and drying the product to obtain the nano SiO2 product, wherein the filtrate mainly contains carbonate M2CO3 and NH3 and also contains little NH4HCO3; and M is an alkali metal Na or K. The preparation method has the following beneficial effects: the filtrate mainly contains M2CO3 and NH3 which can generate MHCO3 and NH4HCO3 through reaction with CO2, and MHCO3 can react with M2O.nSiO2 to obtain the hydrate SiO2 through precipitation, i.e. several components in the filtrate can regenerate the required reaction raw materials through reaction with CO2, so the materials can be recycled, thus the preparation cost of precipitated SiO2 is reduced, simultaneously fewer resources are consumed and emission is reduced.

Description

A kind of preparation method of nano silicon dioxide
Technical field
The present invention relates to a kind of method of producing nano silicon, belong to the new chemical materials technical field.
Background technology
Nano silicon (nm-SiO 2) to be particle size (be generally 1～100nm) soft silica product at nano level; Outward appearance is a white powder; It is a kind of nontoxic, tasteless, free of contamination nonmetal oxide material; Microstructure is three-dimensional netted accurate particle globosity, because of its small size that has, bigger serface, high surface energy, the interface that contacts with polymkeric substance can high characteristics, and superior stability, reinforcement property, thickening property and thixotropy; Have in a lot of fields very and use widely, particularly all more and more manifest the effect that it is not replaced in Application Areass such as rubber, speciality coating, textile industry, polymer matrix composites modifications.
Produce nm-SiO at present 2Method mainly contain two kinds of dry method and wet methods, dry method mainly refers to vapor phase process and arc process, wet method can be divided into the precipitator method and solution-gel method.Use dry method and with tetraethyl silicate as the solution-gel method of presoma owing to there are drawbacks such as the prices of raw and semifnished materials are expensive, preparation cycle is long, with cheap raw material preparing nm-SiO 2The increasing attention that causes people of method.
The 25th the 2nd phase of volume of University Of Nanchang's journal (industry science version) of publishing in June, 2003 has been delivered the article of Zheng Dianmo, Su Xuejun, and " chemical precipitation method prepares nanometer SiO 2Research ", water glass and the sulfuric acid introduced with cheapness are raw material, through the pH value of control solution, adopt the method for chemical precipitation to produce nanometer SiO 2The method of micro mist, the precipitin reaction of this technology is:
Na 2O·nSiO 2+H 2SO 4+(nx-1)H 2O→nSiO 2·xH 2O↓+Na 2SO 4
Remove and generate SiO 2Outward, reaction has also generated Na 2SO 4, at washing SiO 2Can produce a large amount of saliferous (Na during deposition 2SO 4) contain acid (remaining H 2SO 4) waste water, because the factor of aspects such as the concentration and the cost of technology, the cost recovery of these saliferous acid-bearing wastewaters is higher, regenerant is worth little again, therefore inevitably can discharge great amount of wastewater.
Therefore, though above-mentioned technology has solved the problem that substitutes expensive raw materials with cheap material, having brought needs to consume a large amount of mineral acids, and producing a large amount of saliferous acid-bearing wastewaters can't circulate or recycle, and causes problems such as environmental pollution simultaneously.
Summary of the invention
To the problems referred to above; The problem that quasi-solution of the present invention is determined provides outside a kind of silica removal source (soluble silicate); The method of producing nano silicon that other chemical can recycle with the manufacturing cost of further reduction nano silicon, is lacked consumption of natural resource simultaneously; Reduce discharging, reduce infringement as far as possible environment.
For achieving the above object, the present invention adopts following technical scheme: a kind of preparation method of nano silicon dioxide, it is with soluble silicate M 2OnSiO 2And NH 4HCO 3Be raw material, with M 2OnSiO 2And NH 4HCO 3Mol ratio be 1: 1.0～1.15 to react, be settled out hydration SiO 2, warp filters to divide and goes filtrating, and filter cake is again through washing, obtaining the nano silicon product with organic solvent displacement, drying; Mainly contain carbonate M in the said filtrating 2CO 3, NH 3, also have minor N H 4HCO 3Said soluble silicate M 2OnSiO 2, carbonate M 2CO 3In M be alkali metal Na or K, said soluble silicate M 2OnSiO 2In n be its modulus, the n value is 2.2～3.7.
Also pulverize after the said drying.Said filtration is to adopt vacuum filtration or pressure filter to filter.Described washing is the water washing leaching cake, to remove electrolyte ion contained in the filter cake.Described organic solvent displacement is with the filter cake of organic solvent washing after water washing, or removes the contained water of filter cake with the organic solvent azeotropic distillation.
Feed CO in the said filtrating 2, make the carbonate M in the filtrating 2CO 3Reaction generates supercarbonate MHCO 3, NH 3Reaction generates NH 4HCO 3, MHCO 3And NH 4HCO 3Mixing solutions circulation as the reaction raw materials of preparation nano silicon.
Said logical CO 2The mixing solutions that obtains after the reaction also through concentrating, is separated out recovery part MHCO 3, NH 4HCO 3With remainder MHCO 3Mixing solutions circulation as the reaction raw materials of preparation nano silicon.The said MHCO that separates out 3The control of amount is to make NH in the mixing solutions 4HCO 3With remainder MHCO 3Amount can satisfy the requirement of circulating reaction, in promptly enough next circulations with M 2OnSiO 2The amount of reaction.
Adopt technique scheme, preparation method of nano silicon dioxide of the present invention, it is with soluble silicate M 2OnSiO 2With bicarbonate of ammonia NH 4HCO 3For raw material reacts, be settled out hydration SiO 2, obtain the nano silicon product through washing, organic solvent displacement, drying again.Owing to mainly contain carbonate M in the filtrating 2CO 3And NH 3, can through with CO 2Reaction generates MHCO 3And NH 4HCO 3, and MHCO 3Also can with M 2OnSiO 2Reaction makes and is settled out hydration SiO 2(MHCO at this moment, 3Reaction generates M 2CO 3, M 2CO 3With CO 2Circulate again after the reaction and generate MHCO 3), promptly in the filtrating several kinds of compositions through with CO 2Reaction all can regenerate required reaction raw materials.Therefore, by technique scheme, outside silica removal source (soluble silicate); Other chemical can recycle, and compared with prior art, adopt this technical scheme to reduce the manufacturing cost of precipitated silica; Lack consumption of natural resource simultaneously, reduce discharging, reduce infringement environment; Avoid prior art need consume a large amount of mineral acids, discharged a large amount of saliferous acid-bearing wastewaters, caused problems such as environmental pollution.
Do some concise and to the point analysis in the face of technique scheme down.
Make a point earlier, the M described in the technique scheme is sodium Na or potassium K, because Na and K are both alkali metal; The two many corresponding compounds performance is all very close; So mainly be to be that Na performs an analysis with M in following analysis, to M be K situation roughly and the like get final product, or can understand with reference to corresponding document; Like performance to potassium silicate, can be with reference to " production of silicon compound and application " (No. 015, (river) Xindeng word) of press of Chengdu Univ. of Science & Technology in May, 1994 distribution.
Briefly introduce down main raw material water glass below as the preparation nano silicon.
Water glass, popular name water glass, commodity are called sodium silicate, and molecular formula can be write: Na 2OnSiO 2, n is SiO 2With Na 2The mol ratio of O often is called modulus, and the modulus of general water glass product is 2.2～3.7.
Water glass very easily reacts with acid and separates out silicon-dioxide, and the front has been write Na 2OnSiO 2With H 2SO 4The equation of reaction, but in fact, Na 2OnSiO 2Even ability and NH 4 +Such weak acid (Lewis acid) reaction:
Na 2O·nSiO 2+2NH 4Cl+(nx-1)H 2O→nSiO 2·xH 2O↓+2NaCl+2NH 3
Here, NH 4 +Be as an acid:
PKa＝9.25
Similar, Na 2OnSiO 2Also can with HCO 3 -Reaction:
Na 2O·nSiO 2+NH 4HCO 3+(nx-1)H 2O→nSiO 2·xH 2O↓+Na 2CO 3+NH 3
Na 2O·nSiO 2+2NaHCO 3+(nx-1)H 2O→nSiO 2·xH 2O↓+2Na 2CO 3
PKa＝10.3
This is a reaction principle of the present invention.
When using NH 4HCO 3Or NaHCO 3(obtaining after the circulation) makes Na 2OnSiO 2Middle SiO 2After separating out, through washing, can obtaining the nano silicon product with organic solvent displacement, drying, these subsequent treatment process are equal to the production technique that existing water glass acid system is produced nano silicon basically.Replenish some in addition:
1, straining installation: existing straining installation such as pressure filter, vacuum filter all can use in principle, but considers washing effect, and factors such as water saving in the washing process particularly are so use the membrane pressure filter effect can be better.
2, bath water can be directly with tap water or deionized water, the also available little amount of N H that contains 4HCO 3Dilute solution, this is because hydration SiO 2There is adsorptivity on the surface, adsorbs a large amount of Na easily +Ion, simple water is difficult for cleaning.Utilize NH 4 +The ionic exchange interaction can improve the effect of washing.Also available a small amount of rare H 2SO 4Or rare HCl soaks, washing, afterwards again with tap water or deionized water wash, generally is washed till the wash water pH value and gets final product 6～7.Certainly, these processes all can be accomplished in filter.
3, filtrating also can be earlier through reclaiming most of NaHCO 3After, remaining solution carries out circulating reaction, and scheme is: first warp and CO filtrate 2Reaction, cooling makes NaHCO then 3Separate out recovery, NH 4HCO 3With remainder NaHCO 3Mixing solutions circulation as preparation deposition SiO 2Reaction raw materials.This is to have utilized NaHCO 3Solubleness in water is less, and the littler characteristic of its solubleness at low temperatures.
NaHCO 3Solubleness in water is (g/100g water) as follows:
Temperature 0℃ 10℃ 20℃ 30℃ 40℃
NaHCO 3 6.9 8.1 9.6 11.1 12.7
Utilize NaHCO 3Dissolubility property, make NaHCO through cooling 3From solution, separate out, can simplify like this and reclaim NaHCO 3Technological process.The NaHCO that obtains 3Can be used as product reclaims.
4, also recyclable NH in the washing filter cakes liquid 4HCO 3And NaHCO 3, particularly the washing lotion in early stage can further reduce the loss of recycle feed and the discharging of waste liquid like this.
5, certainly, this patent technology needs to use carbonic acid gas in addition, but carbonic acid gas can effectively utilize dioxide gas as a kind of main gas that causes global greenhouse effect, to the same positive effect of preserving the ecological environment.
6, the used organic solvent of replacement solvent can be by producing the recycling use of nano silicon current technology.
Can know that according to above explanation the present invention is only with Na 2OnSiO 2Be raw material, except that need replenished carbonic acid gas, other raw materials all can be recycled; Reduced the manufacturing cost of nano silicon; Also significantly reduced the discharging of waste water, and its concise production process, equipment and fixed capital less input, process advantage is fairly obvious.
Use K 2OnSiO 2, NH 4HCO 3And KHCO 3Circulation also basic identical.
Embodiment
Embodiment 1
Getting a kind of degree Beaume is the water glass of 37 ° of Be ' (20 ℃, down together), and the water that adds 4 times of amounts (weight, down together) dilutes, filters, and records diluent and contains SiO 2%=5.0%, Na 2O%=1.4%, its modulus n=3.7 takes by weighing this dilute solution 600g, under agitation with the NH of 600g 1.8% 4HCO 3Solution mixes (the reaction mol ratio is 1: 1.0), does not have SiO in the liquid phase basically to checking 2, continued stir about 15 minutes, filter, use the clear water washing precipitation, closely neutral to wash water, drain, with the washing with alcohol deposition, drain, dry in baking oven, pulverize again, can obtain the about 27.5g of nano silicon finished product.
At aforementioned filtration elimination hydration SiO 2Post precipitation, about 900g that obtains filtrating, logical CO 2Reaction verifies as NH 4HCO 3And NaHCO 3Mixing solutions, detect wherein NH 4HCO 3Content is 0.9%, NaHCO 3Content is 1.9%.And 1.9% NaHCO 3With the amount of water glass reaction and 0.9% NH 4HCO 3Solution is suitable, like this, the mixing solutions effective content that obtains basically with the NH of preceding preparation 4HCO 3Solution is consistent, and the weight also 600g than former adding is many, is enough to satisfy present embodiment and recycles requirement.
Embodiment 2
Get the water glass that a kind of degree Beaume is 40 ° of Be ', add water dilution, the filtration of 3 times of amounts, record diluent and contain SiO 2%=6.5%, Na 2O%=2.1%, its modulus n=3.2 takes by weighing this rare sodium silicate solution 600g, under agitation contains 2.4% NH with 700g 4HCO 3Solution mixes (the reaction mol ratio is 1: 1.05), does not have SiO in the liquid phase basically to checking 2, continued stir about 15 minutes, filter, with containing 0.5%NH 4HCO 3Tap water washing precipitation 3 times, wash to wash water closely neutrally again with clear water, drain, with washed with isopropyl alcohol deposition several times, drain again, dry in baking oven, pulverize again, can obtain the about 35g of nano silicon finished product.
At aforementioned filtration elimination hydration SiO 2Post precipitation, about 900g that obtains filtrating, logical CO 2Reaction verifies as NH 4HCO 3And NaHCO 3Mixing solutions, detect wherein NH 4HCO 3Content is 1.3%, NaHCO 3Content is 2.6%.And 2.6% NaHCO 3With the amount of water glass reaction and 1.2% NH 4HCO 3Solution is suitable, and like this, its content of the mixing solutions that obtains and amount are enough to the satisfied requirement that recycles.
Embodiment 3
Get the water glass that a kind of degree Beaume is 46 ° of Be ', add water dilution, the filtration of 3.5 times of amounts, record diluent and contain SiO 2%=5.8%, Na 2O%=2.2%, its modulus n=2.7 takes by weighing the rare sodium silicate solution 600g of this kind, under agitation contains 2.6% NH with 700g 4HCO 3Solution mixes (the reaction mol ratio is 1: 1.08), does not have SiO in the liquid phase basically to checking 2, continued stir about 15 minutes, filter, with containing 0.3%NH 4HCO 3Tap water washing precipitation 3 times, with rare H of 0.02M 2SO 4Washing precipitation 3 times is washed to wash water closely neutrally again with clear water, drain; Join in the propyl carbinol, remove the contained water of filter cake, stop heating after distillation is accomplished with component distillation; Use the B suction filtration after being cooled to normal temperature; It is dry that filter cake is put into baking oven, obtains the powder that loosens after the drying, grinds slightly and can obtain the about 31g of nano silicon finished product.
At aforementioned filtration elimination hydration SiO 2Post precipitation, about 1000g obtains filtrating.Collect again and use rare NH 4HCO 3The about 550g of the sedimentary wash water of solution washing.Logical CO 2Reaction checks two solution to be NH 4HCO 3And NaHCO 3Mixing solutions.The solution that detecting filtrates obtains is NH wherein 4HCO 3Content is 1.4%, NaHCO 3Content is 2.75%, and the solution that washings obtains is NH wherein 4HCO 3Content is 0.7%, NaHCO 3Content is 0.8%.
About 1000g solution that filtrating is obtained is depressed slowly careful heating evaporation and is concentrated shading, and to the heavily about 150g of liquid, stops heating, naturally cooling, and to about 20 ℃, filtration is blotted with filter paper, obtains about 15gNaHCO 3Crystal.About 150g that filtrates is with the logical CO of washings 2The 550g solution that obtains after the reaction mixes, and obtains 700g solution, detects wherein NH 4HCO 3Content is 2.3%, NaHCO 3Content is 2.5%, is enough to satisfy the requirement that present embodiment recycles.
Embodiment 4
Getting a kind of degree Beaume is the water glass product of 51 ° of Be ', adds water dissolution, the filtration of 5 times of amounts, records its SiO 2%=4.9%, Na 2O%=2.3%, its modulus n=2.2 takes by weighing this kind solution 500g, under agitation contains 2.4% NH with 700g 4HCO 3Solution mixes (the reaction mol ratio is 1: 1.15), does not have SiO in the liquid phase basically to checking 2, continued stir about 15 minutes, filter, with clear water washing precipitation 2 times; Rare HCl with 0.1M soaks, washing precipitation 3 times, washs to wash water closely neutrally again with clear water, drains, and joins in the propionic acid; Remove the contained water of filter cake with component distillation, stop heating after distillation is accomplished, use the B suction filtration after being cooled to normal temperature; It is dry that filter cake is put into baking oven, obtains the powder that loosens after the drying, grinds slightly and can obtain the about 27g of nano silicon finished product.
Handle filtrating and washings with embodiment 3 identical methods, can obtain about 13gNaHCO 3Solid, and can satisfy the NH that present embodiment recycles 4HCO 3And NaHCO 3Mixing solutions.
Embodiment 5
Press embodiment 1～4, the potassium silicate replacement water glass with close modulus by close amount and volumetric molar concentration, does not change other conditions and technological process, can obtain the nano silicon product of close weight equally, and the volumetric molar concentration of filtrating is basically identical also.

Claims (7)

1. a preparation method of nano silicon dioxide is characterized in that it is with soluble silicate M 2OnSiO 2And NH 4HCO 3Be raw material, with M 2OnSiO 2And NH 4HCO 3Mol ratio be 1: 1.0～1.15 to react, be settled out hydration SiO 2, warp filters to divide and goes filtrating, and filter cake is again through washing, obtaining the nano silicon product with organic solvent displacement, drying; Mainly contain carbonate M in the said filtrating 2CO 3, NH 3, also have minor N H 4HCO 3Said soluble silicate M 2OnSiO 2, carbonate M 2CO 3In M be alkali metal Na or K, said soluble silicate M 2OnSiO 2In n be its modulus, the n value is 2.2～3.7.
2. based on the described preparation method of nano silicon dioxide of claim 1, it is characterized in that also pulverizing after the said drying.
3. preparation method of nano silicon dioxide according to claim 1 is characterized in that said filtration is to adopt vacuum filtration or pressure filter to filter.
4. preparation method of nano silicon dioxide according to claim 1 is characterized in that described washing is the water washing leaching cake, to remove electrolyte ion contained in the filter cake.
5. preparation method of nano silicon dioxide according to claim 1 is characterized in that described organic solvent displacement is with the filter cake of organic solvent washing after water washing, or removes the contained water of filter cake with the organic solvent azeotropic distillation.
6. preparation method of nano silicon dioxide according to claim 1 is characterized in that feeding CO in the said filtrating 2, make the carbonate M in the filtrating 2CO 3Reaction generates supercarbonate MHCO 3, NH 3Reaction generates NH 4HCO 3, MHCO 3And NH 4HCO 3Mixing solutions circulation as the reaction raw materials of preparation nano silicon.
7. preparation method of nano silicon dioxide according to claim 6 is characterized in that said filtrating leads to CO 2After the reaction, the mixing solutions that obtains also through concentrating, is separated out recovery part MHCO 3, NH 4HCO 3With remainder MHCO 3Mixing solutions circulation as the reaction raw materials of preparation nano silicon; The said recovery part MHCO that separates out 3The control of amount is to make NH in the mixing solutions 4HCO 3With remainder MHCO 3Amount can satisfy the requirement of circulating reaction, in promptly enough next circulations with M 2OnSiO 2The amount of reaction.
CN2012101218438A 2012-04-19 2012-04-19 Preparation method of nano SiO2 Pending CN102633266A (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080199385A1 (en) * 2005-06-08 2008-08-21 Evonik Degussa Wellink Silica(Nanping) Co. Ltd. Process for Producing Silica and Sodium Sulfite with Sodium Sulfate
CN101323453A (en) * 2008-07-04 2008-12-17 武汉工程大学 Circulation novel process for preparing white carbon black
CN102092723A (en) * 2011-03-30 2011-06-15 廖险峰 Method for preparing high dispersing white carbon black with ammonia precipitation method

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080199385A1 (en) * 2005-06-08 2008-08-21 Evonik Degussa Wellink Silica(Nanping) Co. Ltd. Process for Producing Silica and Sodium Sulfite with Sodium Sulfate
CN101323453A (en) * 2008-07-04 2008-12-17 武汉工程大学 Circulation novel process for preparing white carbon black
CN102092723A (en) * 2011-03-30 2011-06-15 廖险峰 Method for preparing high dispersing white carbon black with ammonia precipitation method

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Application publication date: 20120815