CN1155514A - Manufacture of high purity, high concentration and high granularity large granular silicon dioxide gel - Google Patents

Abstract

An improved process based on an existing technology for preparing high-purity, high-concentration, high-uniformity greate-particle SiO2 sol features making use of ammonia-type strong acid is cationic exchange resin for metal ion exchange to stabilize ammonia, and making use of millipore ultrafiltration film to filter out particles less than 20 nm. Its advantages include small particle content less than 2%, easy operation and low cost of apparatus and energy consumption.

Description

The manufacture method of the large granular silicon dioxide gel that high purity, high density, high single-size distribute

The invention belongs to the compound goods class of chemical field.It relates to a kind of method of manufacturing technology of high-purity silicon dioxide colloidal sol.

Highly purified silicon dioxide gel has purposes widely, and it can be used as the carrier of high purity catalyst, can make the tackiness agent of high purity silicon hydrochlorate, also is very necessary to the manufacturing of semi-conductor silicon sheet polish.The existence, particularly Na, K, Al, Fe, the Mg that in the high-purity silicon dioxide colloidal sol of prior art, all also have a certain amount of metal ion, promptly or have trace-metal to exist or the bad technical requirements that all can not satisfy above-mentioned field product of uniform particles degree.Relevant high-purity silicon dioxide colloidal sol preparation method's patent is a lot, obtains some relevant patented technologies through the individual with the retrieval of Patent Office of the People's Republic of China, now is summarized as follows.1. CN1036547A " stable silica sol and method for making thereof ", it is to add foreign ion calcium, magnesium etc. in silicate solutions, generates the slender type colloidal particle, characteristics are that adhesion property is good, can be used in the plastic coating, and are different with the application's theme and method; 2. WO91/07351,3. WO91/07350 " production method of silicon dioxide gel and uses thereof ", these two pieces is same author's identical patent, it is that to make high specific area be short grained colloidal sol with adding high-content basic metal, be used on the additive or cation high molecular wedding agent of paper industry, content obvious and this patent is also inequality; 4. EP0504467A1,5. EP0537375A, 6. three pieces of EP0557740A2 all are patents of preparation high-purity silicasol, identical substantially on manufacture method, something in common is:

1, dilute silicate solution obtains acidic silicasol with resin cation exchange;

2, add ageing, i.e. ionization after strong acid H2SO4, HNO3, oxalic acid or the salt;

3, again through the zwitterion resins exchange, further remove ion;

4, get part with the stable end liquid of making of K, Na alkali;

5, end liquid heating adds active colloidal sol down in that alkali is stable, makes particle growth, and the activity gel amount that evaporates the water yield and adding under boiling equates;

6,, remove the stable metal ion of introducing of alkali again through the zwitterion exchange;

7, stir ammonification down and carry out stabilization.These three pieces of patents and this patent also have points of resemblance; 7. in the EP0464289A3 patent, the 4th step by above method is stable with ammonia, therefore in the 5th step, can not be heated to and boil, this strengthens reaction volume and makes troubles, but can remove the 6th operation from, the danger of frozen glue is arranged in the 7I preface, because silicon sol is least stable when pH value is 5-6, then all scrap if frozen glue takes place, do not have the possibility that reverses; 8. JP61-158810 " method for making of high-purity silicasol ", it adopts the cationic exchange sodium silicate solution to generate silicic acid sol, use membrane concentration after adding mineral acid, add NH3 or organic amine then, the heating back drips part colloidal sol and makes its particle growth, does not add complex compound here and handles, with ammonia or amine stabilized, for preventing that NH3 overflows in the colloidal sol, with membrane concentration small-particle colloidal sol, over-burden for film earlier; 9. US.4356107, it proposes a kind of manufacture method of single-size distribution macrobead silicon sol, it uses the raw materials of silica sol of wide size distribution to react 5 hours under 280 ° of-345 conditions as 8-10.5, temperature at PH, and small particle silicas is dissolved in alkaline aqueous phase.The particulate uniformity coefficient is improved, make short grained number average drop to 5% from 50%, this manufacturing processed need heat, pressurizing device, and fouling easily, and energy consumption is bigger.

The object of the present invention is to provide a kind of improved production method, make technology easier, effective, advanced, and directly prepare the macrobead silicon sol of high purity, high evenness.

By as above design, the technological process of the manufacture method of the large granular silicon dioxide gel that the high purity that this programme provided, high density, high single-size distribute comprises:

1, the preparation silicate solutions removes metal ion through Zeo-karb and gets acidic silicasol;

2, add oxalic acid, mineral acid treatment in acidic silicasol, ageing is after anionresin and cationic exchange get acidic sol;

3, in the part acidic sol, add potassium or sodium salt stabilization, and the acidic sol that adds low-metal content with boiling process obtains alkaline colloidal sol to increase particle;

4, remove metal ion with Zeo-karb;

5, under agitation add ammonia with membrane concentration, obtain the stable silicon dioxide gel of ammonia, it is characterized in that in the 4th step, alkaline colloidal sol being added deionized water, with the metal ion that the step forms when operation adds basic metal before removing, obtain the stable alkaline silica sol of macrobead ammonia by ammonia type storng-acid cation exchange resin; Adopted the micropore ultra-filtration membrane to sieve before the membrane concentration in the 5th step, the aperture of filter membrane is 25-65nm, and the particle that elimination 20nm is following gets oarse-grained silicon dioxide gel.

Ammonia type strong acidic ion resin is to make through renovation process on the resin cation (R.C.) of H type with 5%NH4OH liquid in this programme.Its screening micropore ultra-filtration membrane is the micropore filtering film of vinyl fluoride, selects for use polyethers, carbon fibre and vinylidene material to make, and that its membrane module can make is flat, the shape of roll type or tubular type.

Adopt this programme can embody following superiority: 1. in the 4th of technological process goes on foot use ammonia type storng-acid cation exchange resin can with potassium ion and other metal ion exchanged in the colloidal sol, and directly obtain low-metal content, the alkaline colloidal sol that high purity ammonia is stable, easy to operate, prior art is carried out ammonia with NH4OH or organic amine adding acidic sol and is stablized, the bad grasp of this kind technology, easily produce frozen glue when the stage of colloidal sol experience pH value 5-6, can cause falling flat, moreover carry out alkali with NH4OH and stablize, heating back NH3 overflows serious, therefore can not use boiling process, the particle packing process of growth volume of a container of colloidal sol increases greatly like this, and is expensive big on the equipment and the energy; 2. using KOH to carry out alkali in the 3rd step in technological process stablizes, and without NH4OH, no NH3 effusion problem can be heated to boils, add active acidic sol and make particle growth, and then remove potassium ion with ammonia type resin cation (R.C.), make finished product purity height, method is effectively advanced, is easy to realize suitability for industrialized production; 3. sieve with the micropore ultra-filtration membrane earlier after making alkaline ammonia stable sol, remove the following small-particle of 20nm, contract through film is molten again, obtain 30% or oarse-grained, the high-purity high dense colloidal sol of 50%SiO2 concentration, the quality product of the digital proof this programme production that detects through Electronic Speculum repeatedly occupy international most advanced level.

Describe two embodiment of this programme below in detail.

Embodiment one, lab scenario:

1, with commercially available water glass SiO2: Na2O=3: 1, be diluted to SiO2 content 4-5% with pure water, allow it pass through storng-acid cation exchange resin, this resin is vinylbenzene and benzene divinyl crosslinking sulfonic acid H type resin, obtains acidic sol, PH=3.

2, get the acidic sol of 25Kg, add oxalic acid 25g, stir dissolving down, add 10ml 98% dense H2SO4 again, PH=1, solution colour are yellow-green colour, after the ageing 18 hours, by strongly basic anion exchange resin, resin is vinylbenzene and benzene divinyl interpolymer three methylamino-s (OH) type, and it is standby that it collects liquid PH=4;

3, in 10 liters there-necked flask, adorn agitator, condenser and thermometer, add 3000ml deionized water and 1000ml acidic sol, with the pure KOH liquid of 20% reagent, pH value is transferred to 10-11, be heated to and boil, add above-mentioned acidic silicasol with certain speed, keep the constant evaporation down of liquid level, growth response 10 hours, PH=8.5-9.5;

4, getting above-mentioned basic solution is base fluid 1000ml, add deionized water 2500ml, PH=9-10, be heated to and boil, the permanent liquid evaporation of acidic sol that adds the above-mentioned low-metal content that makes continuously, the KOH solution pure with 20% reagent transfers to PH=9-10, joining day is 20 hours, adds acidic sol 16000ml, obtains silicon sol content 23.1% (in SiO2), PH=9.1, by ammonia type strong acidic ion resin exchange column, this resin is with the making of regenerating on H type strong acidic ion resin of NH4OH solution, its collection liquid PH=8.5 with above-mentioned alkaline colloidal sol, obtain colloidal sol 4000ml, concentration is 18.2%.Detecting average particle size through the TEM Electronic Speculum is 45nm, and metal ion content is

Na 41PPm records with atomic absorption spectrometry

K 80PPm ″

Fe 15PPm ″

Mg 5PPm ″

Al 50PPm gets with the colorimetry side

5, above-mentioned colloidal sol is sieved through the micropore ultrafiltration membrance filter, the bore of film is 25-60nm, three times of deionized waters filter three times in addition, getting average particle size is 51nm, detects through the TEM Electronic Speculum, and the following small-particle of 20nm drops to 2% from 50%, pass through membrane concentration again, filter membrane component is a roll type film post, is concentrated into for 50% (containing SiO2), finally obtains proportion and be 1.38 finished product colloidal sol.

Embodiment two, the suitability for industrialized production scheme

Its production process is identical with last example, cationic exchange coloum wherein, anion-exchange column, ammonia type highly acidic cation exchange column is respectively 4,2,2, column diameter is 800mm, high 2000mm, interior dress resin 600Kg, the particle growth retort is 400 liters, structure is that stainless steel has the steam-heated cal(l)andria chuck, have agitator and condenser, membrane module is two on a roll type post, and processing power is 200Kg/ hour, one on ultra-filtration membrane roll type post, processing power is 200Kg/ hour, single pot of acidic sol 4T that feeds intake during production, the reaction times is 24 hours, being characterized as of products obtained therefrom silicon sol:

Concentration 45～50% (SiO2 meter)

Proportion 1.37～1.39

PH 9.5～10.0

Average particle size 40～50nm

20nm particle＜2%

Metal ion content is in SiO2

Na＜50PPm

K?＜100PPm

Al＜100PPm

Fe＜15PPm

Mg＜5PPm。

Attached: the relevant technical data of made Ludox in the data searching (for contrast):

1, the metal ion content in the JP63-285112 patent gained Ludox

More than the Na 800PPm

Al  50PPm

Fe  30PPm

The decentralization of the granularity of this colloidal sol is wider.

2, the metal ion content of the obtained colloidal sol of EP0462289A2 patent

Na＜100PPm

Al＜30PPm

Fe＜25PPm, and granularity is disperseed broad.

Claims (3)

1, the manufacture method of the large granular silicon dioxide gel of a kind of high purity, high density, the distribution of high single-size, its technological process comprises

(1) the preparation sodium silicate solution removes metal ion through Zeo-karb and gets acidic silicasol;

(2) in acidic silicasol, add after oxalic acid, the mineral acid treatment ageing and get acidic sol through the moon from exchange and cationic exchange again;

(3) in the part acidic sol, add sylvite or sodium salt stabilization, and the acidic sol that adds low-metal content with boiling process obtains alkaline colloidal sol to increase particle;

(4) remove metal ion with Zeo-karb;

(5) use membrane concentration, ammonification under agitation, get the stable silicon dioxide gel of ammonia, it is characterized in that in the 4th step, colloidal sol being added deionized water by ammonia type storng-acid cation exchange resin, metal ion so that the step forms when operation adds basic metal before removing obtains oarse-grained ammonia and stablizes alkaline silica sol; Adopted the micropore ultra-filtration membrane to sieve before the 5th step membrane concentration, the filter membrane aperture is 25-65nm, and the particle that elimination 20nm is following gets large granular silicon dioxide gel.

2,, it is characterized in that ammonia type strong acidic ion resin is to make through regeneration on the resin cation (R.C.) of H type with 5%NH4OH liquid according to the manufacture method of the described silicon dioxide gel of claim 1.

3, according to the manufacture method of the described silicon dioxide gel of claim 1, the screening micropore ultra-filtration membrane that it is characterized in that it is the micropore filtering film of vinyl fluoride, select for use polyethers, carbon fibre and vinylidene material to make, that its membrane module can make is flat, the shape of roll type or tubular type.