JPS5818327B2 - crystalline silica - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention generally relates to novel crystalline silicas and methods of making the same.

More particularly, the present invention provides a novel crystalline silica which exhibits the molecular sieve properties of many crystalline aluminosilicates, but which does not contain the ion exchange essential for this type of salt, commonly referred to as zeolite molecular sieves. This relates to the above-mentioned silica, which does not exhibit any properties.

Although crystalline form of silica is found in nature, it also exists as a synthetic form that has no apparent natural counterpart.

Crystalline forms of silica found in nature include quartz, alinite, and cristobalite, each of which has homogeneous polymorphisms that are stable over various humidity ranges.

At normal temperatures, the stable form is α-quartz.

At 573°C, it transforms into β-quartz, which is stable up to 867°C.

Thus, at this humidity level, phosphorite becomes a stable phase and maintains this state up to 1470°C.

Above 1470°C, cristobalite is a stable phase and remains in this state up to about 1713°C.

The first true silica polymorph to be synthesized was conisite (coes 1te) silica.

Details of the definition of this crystalline composition and its manufacturing method were published here on March 3, 1959, and by Coes.
s), Jr., U.S. Pat. No. 2,876,072.

Also, molecular sieve type. It has been proposed to produce crystalline polysilicates by treating crystalline aluminosilicates with steam, strong acids or organic chelating agents to extract aluminum from the tetrahedral framework structure of the silicates. There is.

The product after precursor composition is a pseudoimage. For detailed methods of this kind, please refer to the page published on April 14, 1970.
,Eberly\Jr.

No. 3,506,400.

Thus, although the composition of the latter is assumed to consist solely of silica, it appears to persist as a defective structure with the same amount of silica per unit cell as its aluminosilicate precursor.

In at least some instances of extracting aluminum from the zeolite framework structure, the extraction is reversible so that similar elements such as germanium can be inserted into the tetrahedral structure.

Regarding this, please refer to P. published on February 8, 1972.
E. Pickert U.S. Patent No. 3,64
See No. 0,681.

Below [Silicalite]
The crystalline silica polymorph of the present invention, designated as j, has a specific gravity of
It has a specific gravity of 1.99±0.05 g/CC at 5°C.

In the form after smoldering (1 hour at 600° C. in air), the silicalite has a specific gravity of L70 g ± 0.059/cc.

When measuring the average refractive index of the as-synthesized and after-smoking (600°C in air for 1 hour) silicalite crystals, the average refractive index is 1.48±0.01 and 1.39±, respectively. A value of 0.01 is obtained.

The above values are listed in Table 1 together with values for refractive index and density of other forms of crystalline silica for comparison.
oscopic determination of
theNonopaque Minerals) J,
2nd edition (Geological 5urvey Bull
ietin 848, E. S., Larsen and.
H. Berman, 1934) and [Dana mineralogy (
DaJs System of Mineralology)
J, 7th edition (C1ifford Frondel, 1
Data from 962).

X- of Silicalite (smoked at 600°C for 1 hour in the atmosphere)
The line powder diffraction pattern consists of its six strongest lines (i.e., layer line spacing, 1nterpFnar spacin-gs
) has the values shown in Table A below.

In this table, "S" = strong, l'-VSj-very strong.

Table A d-A Relative intensity 11.1±0.2 VSlo, 0±〇, 2 VS 3.85±0.07 VS 3.82±0.07 8 3.76±0.05 8 3.72± 0.05 8 51.9 moles of 8 per 201 moles of (TPA) produced according to the method of the present invention (calcination at 600° C. for 1 hour in air)
Data showing the X-ray powder diffraction patterns of representative silicalite compositions containing 102 are presented in Table B below: Table B d-A Relative Intensity d-A Relative Intensity 11.
1 100 4.35 5
10.02 64 4.25
79.73 16 4.08
38.99 1 4.00
38.04 0.5 3.85
597.42 1 3.
82 327.06 0.5
3.74 246.68 5
3.71 276.35 9
3.64 125.98 1
4 3.59 0.5d-A Relative intensity d-A Relative intensity 5.70
7 3.48 35.57
8 3.44 55.36
2 3.34 115.11
2 3.30 75.01
4 3.25 34.98
5 3.17 0.54
．． 86 0.5 3.13
0.54.60 3 3.05
54.44 0.5 2.9
8 10 Silicalite crystals are synthesized with N
It is an orthorhombic system in both the morphology and the morphology of burnout, and exhibits the following unit cell parameters: a-
20.05 people, Dan = 20.0 people, Dan - 13.4 people.

Note that the accuracy regarding each value is ±0.1 person.

The pore diameter of silicalite is about 6λ units, and when its pore capacity is measured by adsorption method, it is 0.18 CC/
It is g.

Silicalite is produced by neopentane (dynamic diameter 6.5 mm) at ambient room temperature.
2 people) will be slowly absorbed.

Due to its uniform pore structure, the silicalite composition has size-selective molecular sieve properties and its pore size allows it to separate p-xylene from o-xylene, m-xylene and ethylbenzene.

Also, when using silicalite as a dimensionally selective adsorbent, compounds with quaternary carbon atoms can be
It can be separated from compounds with carbon bonds.

This adsorbent also has very useful hydrophobic/organophilic properties.

This allows the use of the adsorbent in the selective adsorption of organic substances from water in the liquid or gas phase.

However, neither silicalite nor its silicate precursor exhibits ion exchange properties.

The lack of said ion exchange capacity in the silica compositions of the present invention is highly advantageous.

Thus, certain aluminosilicate zeolites can be treated to promote hydrophobic properties and to render the zeolite capable of selectively removing organic matter from wastewater.

However, if a hydrophobic aluminosilicate adsorbent has residual cation exchange capacity, this can be detrimental to the adsorbent when it comes into contact with a wastewater stream containing a source of cations.

Thus, the hydrophobic properties and/or pore size of such aluminosilicate adsorbents change rapidly upon immobilization of cations on the adsorbent.

However, silicalite is not affected by the presence of cations in wastewater streams.

The separation process contemplated herein generally involves contacting an aqueous solution, such as a wastewater influent, containing organic compounds with a silicalite, adsorbing at least a portion of the organic compound onto the internal adsorption surface of the silicalite, and then treating optionally recovering the aqueous solution as an effluent stream.

The production of silicalite consists of hydrothermal crystallization of a reaction mixture consisting of water, a silica source, and an alkylonium compound at a pH of 10 to 14 to form an ice-containing quality precursor, which is then smoldered to form a This includes decomposing the alkylonium moiety.

The exact structure of the precursor is not known. Since the precursor does not exhibit any ion exchange capacity and it does not contain the A104-tetrahedron as an essential framework structural component, the alkylonium compound has no ion exchange capacity, such as that found in aluminosilicate zeolites to balance its negative valence. No need to provide cations.

However, the main function of alkylonium compounds is S
It can be theorized that the arrangement of r 04 tetrahedra provides a template-like material that facilitates the specific lattice shapes that characterize the silicalite compositions of the present invention.

Although we do not wish to be bound by this theory, the observable properties of the precursor indicate that the alkylonium moiety is Si
This indicates that it is more appropriate to consider it as only an occluded element in the frame structure of 04, rather than as a constituent component of that structure.

The alkylonium cation is preferably a compound soluble in the reaction mixture of the general formula: where R is an alkyl group containing 2 to 6 carbon atoms and X represents either phosphorus or nitrogen. .

Preferably, the reaction mixture is optionally fed with a compound as described above containing a quaternary cation represented by R is ethyl, propyl or n-butyl, in particular propyl, and X is nitrogen.

Examples of such compounds include tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, tetrabutylphosphonium hydroxide and corresponding salts of these hydroxides, especially chlorides, etc. and bromide salts such as tetrapropylammonium bromide.

Such a quaternary compound can be fed as such to the reaction mixture or can be formed in situ, such as by reaction of a tertiary amine; with an alkyl halide or sulfate.

When the quaternary cation is supplied in the form of hydroxide in an amount sufficient to establish basicity equal to pH 10-14, the reaction mixture need only contain water and the reactive form silica as additional components. shall be.

If it is necessary to raise the pH above 10, ammonium hydroxide or alkali metal hydroxides, in particular lithium, sodium or potassium hydroxides, can be suitably used for that purpose.

Thus, even if the quaternary cation is not supplied in the form of its hydroxide, the amount of alkali metal oxide required for the above purpose is 6.5 per mole of quaternary cation.
It turned out to be less than a mole.

The source of silica in the reaction mixture can be wholly or partially an alkali metal silicate, but the source should be used in an amount greater than the amount that changes the molar ratio of alkali metal to quaternary cation described above. Not.

Other sources of silica include reactive amorphous silica solids such as fumed silica, silica sols and silica gels.

Since the nature of the reaction system favors alumina contamination in the crystalline silica product, care should be taken in selecting a silica source from the standpoint of its alumina content as an impurity.

Commercially available silica sol typically contains 500 to 7 Al2O3.
00p-, and fumed silica contains Al2O3
It may contain impurities from 80 to 2000 pI)m.

The small amount of Al2O3 present in the silicalite product never significantly changes the essential properties of the silicalite, so even if the silicalite contains alumina or other oxide impurities, the silicalite It is never correct in any sense to think of it as a metal silicate.

The amount of silica in the reaction system should be between 13 and 50 moles per mole of quaternary cation (S 102 ).

In addition, water is 150 to 1 mole of quaternary cation.
It should be present in an amount of 700 molar.

Therefore, when structuring the crystalline silicalite precursor,
present Q20, where Q is a quaternary cation having the formula R4X+, where each R represents hydrogen or an alkyl group containing from 2 to 6 carbon atoms and X is phosphorus or nitrogen; 1 mole converted to the number of moles of oxide
50-700 moles of water, 13-50 moles of amorphous 5i0
A reaction mixture with a pH of at least 10 is formed containing 2 and 0 to 6.5 moles of M2O, where M is an alkali metal.

The order of mixing the reagents is not a critical factor.

The reaction mixture is heated under an autogenous pressure of about 100 to 250°C until crystals of the silicalite precursor form, usually about 50 to 150 hours.
The temperature is kept at ℃.

Crystalline products are obtained by any convenient means such as filtration.

Advantageously, the product can be washed with water and dried at an atmospheric temperature of about 100°C.

When using alkali metal hydroxides in the reaction mixture, alkali metal moieties appear as impurities in the crystalline product.

The form of these impurities present in the crystalline product has not yet been determined, but it is not present as a cation undergoing reversible exchange.

The quaternary cationic moieties are quite easily pyrolyzed and removed by calcination in an oxidizing atmosphere (atmospheric air) or in an inert atmosphere at temperatures ranging from about 480 DEG C. to 1000 DEG C.

Thus, residual alkali metals in the product can be removed by washing with a solution of an alkali metal halide or an aqueous solution of a sufficiently strong acid such as hydrochloric acid.

The crystal structure of the product is not affected by contact with strong mineral acids even in the outer abyss due to the absence of acid-soluble components in its structure.

The method for producing silicalite and the characteristics of its chemical and physical properties are illustrated by the following example. Part 1 (a) Dissolve 1.4 g of sodium hydroxide in 10 g of water;
The solution thus formed was added to 44 g of an aqueous colloidal silica sol with a 5i02 content of 30% by weight to prepare a reaction mixture.

Then, tetrapropylammonium bromide 2.4
g in 1 liter of water to obtain 4.1 moles of Na20, 50.0 moles of SiO2, and 691 moles of H2 per mole of tetrapropylammonium hydroxide.
A total reaction mixture containing O was formed.

The above synthetic mix was placed in a pressure vessel lined with an inert plastic material (polytetrafluoroethylene) and heated at 200° C. for 72 hours.

The solid reaction product was collected by filtration, washed with water, and dried in air at 110°C.

Therefore, the X-ray powder diffraction pattern of this silicalite precursor and the pattern shown by a type of aluminosilicate zeolite composition usually called "ZSM-5 group" are different even though they are clearly different in composition. It was very similar though.

For the latter significant contour, see U.S. Patent No. 3,728,4.
It is written in No. 08.

Chemical analysis of the crystalline silica composition revealed that per mole of silica, 0.016 mole of tetrapropylammonium (TPA) ions as (TPA)20, Na2Oo,
The presence of 11 mol of O and 0.8 mol of H2O was indicated.

Alumina impurities were also present, approximately 650 pp by weight.

(b) A portion of the solid crystalline silica product obtained in (a) above was baked at an atmospheric width of about 600° C. for 1 hour.

After cooling to room temperature in ambient atmosphere, the adsorption properties of the produced silicalite were determined using McBainB.
It was measured using a gravity adsorption device.

In this apparatus, the samples were activated by heating to 350° C. for 16 hours under reduced pressure.

Subsequently, adsorption measurements on various adsorbates were carried out at a pressure of 750 Torr and at various temperatures, and the following data were obtained: Adsorption Dynamic diameter, A adsorption humidity 4'C adsorption rate, weight % oxygen 3. 46 -183 13.7 0-Butane 4.3 23 7.5SF6
5.5 23 18.7 Neopenkun
6.2 23 0.4 Example 2 Using essentially the same procedure as Example 1, 3 g of tetrapropylammonium bromide, 25 g of water, 44 g of aqueous colloidal silica sol (810230% by weight) and 2.3 g of KOH
(TPA)20.3.25 to 20.40.08iO2.
A reaction mixture was formed having an oxide molar ratio of 560H20.

After holding the mixture at 200°C for 72 hours, the crystalline product was isolated by filtration, washed with water, and dried at 110°C.

A portion of the product was subjected to X-ray analysis and chemical analysis, and the product was identified as silicalite.

Its chemical composition, converted to the number of moles of oxide, is 1.0 (TPA), 20.0.63 and 20.52.7S.
It was iO2.9.5H20.

Alumina impurities were also present in an amount of 591 pI)m.

Example 3 In this example, 10 g of (C3H7)4NBr is added to 20 g of H2O.
Dissolve 8g and add this solution to silica sol (30% 5in2
) Silicalite was prepared by adding to 158.4 g of silicalite under stirring.

A solution of 10:1 NaOH in 20 g H2O was then added to the above synthesis mix under stirring.

The molar composition of the synthesized oxide was as follows: (TPA) 20 ・6.2 Na 20 ・38.4 S
102 ・413H20° The synthetic mix was placed in two glass jars lined with plastic.

Heat one mix at 100°C for 72 hours and heat the other mix at 100°C for 72 hours.
Heated at 00°C for 144 hours.

The solid reaction product was collected by filtration, washed with H2O, and dried at 1108C.

Both products were identified as silicalite by X-ray and chemical analysis.

The product crystallized in 72 hours had the following composition: 1.5% by weight Na2O, 7% by weight C, 7% by weight NO, 96% by weight; loss on heating 15.5% by weight.
, Al2O3 impurity 769 ppm.

A portion of the product was stored at 600°C with air purge for 72 hours.
Smoked for hours.

(1) 1 g of the calcined product was added to 107 nl of a 1.0% by volume n-butanol solution in H20 and shaken.

When this treated solution was analyzed by gas chromatography, the time-baked silicalite adsorbent selectively removed 98.8% of n-butanol from the solution.

In another test illustrating the selectivity of silicalite over H2O with respect to organics, one of the above smoldering products
g sample in a 0.1 wt.% phenol solution in H2010
Add to rrLl and shake.

Gas chromatography analysis of the solution brought into contact with this time-baked silicalite revealed that the silicalite adsorbent removed 81% of phenol from the solution.

In another test, this time illustrating the separation of aromatics, a 1 gram sample of the time-calcined product described above was contacted with 10 ml of a 1.0% by weight benzene solution in cyclohexane and shaken.

As analyzed by gas chromatography, the adsorbent removed 46.1% by weight of benzene from the solution.

Example 4 Dissolve (C3H7)4NBr 9.9 El in 25g of water, add Ag2O5, (Bi', and dissolve (C3H7)4NO
A H solution was prepared.

After heating to about 80°C, the precipitated AgBr (C3H
7) The 4NOH solution was separated by filtration and this solution was added to aqueous silica sol (30% SS102) 44 with manual stirring.

The molar composition of the synthesized oxide was as follows: (TPA)20.13.3Si02.184H20 The above synthesis mix was placed in a pressure vessel lined with polytetrafluoroethylene, and at about 72
heated for an hour.

The solid reaction product was collected by filtration, washed with H2O, and dried at 110°C.

A portion of the solid product was subjected to X-ray and chemical analysis.

The solid silicalite analyzed showed the characteristic physical properties described above.

The total solids were analyzed as 0.19% by weight Na20, 8.1% by weight C, 991% by weight N0, 287.4% by weight Sio and 1.5% by weight H2O.

The trace amount of N a 20 is attributed to the silica sol reagent.

Example 5 The silicalite of this example was prepared by adding (C3H7)4NB to 30g of water.
r9. Dissolve Og and add this solution to 100g of H2O.
It was prepared by adding 39.6 g of fume silica to a slurry.

Next, 4.2 g of NaOH was added to this synthesis mix with H2.
A solution in O3'l was added under stirring.

The synthetic oxide composition molar ratio was as follows: (TPA)20-3.25Na20-40Si02-5
52H20° The silicalite product obtained by crystallizing this synthesis mixture for 70 hours at 200° C. was found to contain only 155 pl]I[l of alumina as an occluded impurity.

Example 6 The silicalite of this example was prepared by adding (C4Ho)4PC to 50g of water.
110,1 and adding this solution to 44 g of an aqueous colloidal silica sol (30% by weight SiO□) under stirring.

Next, 1.4 g of NaOH was added to this synthesis mix.
A solution of 50 g of O was added.

The molar composition of the synthesized oxide was as follows.

(TBP)20・1.08Na20・13.3SiO2
・Pour the synthetic mix into a pressure vessel lined with 441H20゜polytetrafluoroethylene, and reduce the autogenous pressure to about 2
Heated at 00°C for 72 hours.

The solid reaction product was collected by filtration, washed with H2O, and dried at 110<0>C.

The crystalline product was identified as silicalite by its characteristic X-ray powder diffraction pattern and chemical analysis.

Therefore, this material showed the following composition: Na 200,
6% by weight, C6.5% by weight, P 1.1% by weight, S
i0288.0% by weight, H2O2, 4% by weight.

The oxide molar composition of the product was as follows: (TB
P)2()0.58Na2()87.3Sio2・7.
9H20°, 'A sample of the product was heated at an atmospheric width of about 600°C.
I wasted my time.

Next, this baked sample was placed in a matsukubain-vacuum type gravity adsorption device and activated at 350°C under reduced pressure for about 16 hours.

The active sample was 14.1% by weight at 750 Torr and -183°C.
adsorbs 0□ of □750 Torr and 7.
7% by weight n-butane, 21.1% by weight SF6 and 0.5% by weight neopentane were adsorbed.

Example 7 The silicalite of this example was prepared by adding (C2H5)4, N
It was prepared by dissolving 7.2 g of Br and adding this solution to an aqueous silica sol (30 wt% SS102) 44 under stirring.

Next, add 1.4 g of NaOH to 1 g of water to this synthetic mix.
A solution prepared by dissolving 0g of the solution was stirred at the bottom nD.

The molar composition of the synthesized oxide was as follows: (TEA)20 ・1.08Na20+13.3S10
2・■84H20゜Pour the synthetic mix into a pressure vessel lined with tetrafluoroethylene, and reduce the autogenous pressure to about 20℃.
Heated at 0°C for 72 hours.

The solid reaction product was collected by filtration, washed with H2O, and dried at 110°C.

This product was identified as silicalite.

Example 8 Dissolve (C3H7) and 13.5 g of NBr in 30 g of water, add Ag2O7,5& (C3H7), and NOH
A solution was prepared.

From AgBr (C3
H7) The 4NOH solution is separated by filtration and the solution is then slurried in 54 g of water [Cab-O-Sil (
Cab-0-8i l) J Huyum Silica 20.8g
mixed with.

The molar composition of the synthesized oxide was as follows: 2(TPA)20.13.3Si02.184H20° The synthesis mix was placed in a pressure vessel lined with tetrafluoroethylene and heated at about 200° C. under autogenous pressure for about 72 hours.

The solid reaction product was collected by filtration, washed with H2O, and dried at 110<0>C.

A portion of the product was subjected to X-ray analysis and had the d-values listed in Table A.

Chemical analysis of the product also showed the following composition: C8, 7% by weight, NO, 81% by weight, 5in28'7.
3% by weight, 1.0% by weight of H2O, A120390 (匍)
Sir and Na2O501) below PI.

The structural oxide molar composition of the product was as follows: (TPA)20.48.2Si02.1. ．． Although we did not intentionally add Na2O or Al2O3 to the 8H20° synthesis mix, the silica source contained trace amounts of Al2O.
3 and N a 20, which were incorporated into the product.

A sample of the product was smoked at about 600° C. for 1 hour.

The active sample adsorbed 18.2 wt% 02 at 750 Torr and -183 °C, 9.9 wt% n-butane, 26.6 wt% SF2 and 0.5 at 750 Torr and 23 °C.
% by weight of neopentane was adsorbed.

Example 9 (C3H7) 4 NB r 10-9 in 30 g of water
Dissolve g and add this to 100 g of H2O and NH40H35
slurry in a mixture of '[Ucar]
It was added to 49.4 g of J Huyum silica.

The molar composition of this synthesized oxide was as follows: (TPA) 20.1.3 (NH4) 20.40 S
102.365H20゜ Place the synthetic mix in a pressure vessel lined with tetrafluoroethylene, and add approximately 200
It was heated at ℃ for 95 hours.

The solid reaction product was collected by filtration, washed with H2O, and dried at 110°C.

When a portion of the product was subjected to X-ray analysis, the X-
The line diagrams were found to indicate the d-values listed in Table A.

Example 10 A sample of calcined silicalite produced by the method of Example 1 (200°C synthesis, 6008°C firing) was stirred with an aqueous solution of HCI or NaCl as outlined below to remove residual alkali metals. The excellent stability of the silicalite was then illustrated by treating the essentially pure SiO□ product derived from sample number 2 with steam at 600° C. under 1 atmosphere for 6 hours.

Thus, the product still exhibited the unique and characteristic properties of silicalite.

Further illustrating the remarkable selectivity over water of the silicalite compositions of the present invention with respect to organic materials, Examples 11-
13 are listed in Table C.

The procedure used in these examples was the same as described in Example 3 above.

■1.0g sample of calcined (600℃) silicalite and an aqueous solution of the following organic compound 10. ON was placed in a serum bottle, capped, shaken, and allowed to equilibrate for at least 12 hours.

For comparison, a blank (an aqueous solution of the same organic compound but without the adsorbent) was always used.

The treated solution was analyzed by gas chromatography.

*bv - volume %, bw - weight %.

(a) Synthesized at 200°C (b) Synthesized at 100°C Example 14 1 g of silicalite synthesized at 200°C and calcined at 600°C by the same procedure as described in the last paragraph of Example 3 above. The sample was contacted with 10 Tnl of a 1.0% by weight benzene solution in cyclohexane.

As a result, gas chromatography analysis revealed that 23.8% of benzene was removed from this solution.

These data indicate that separation can be achieved by silicalite even though the size differences in the adsorbate molecules are very small.

The above information regarding the separation power of silicalite proves that various useful industrial processes can be realized using this adsorbent.

Examples of organic components often found in various industrial effluents or major sewage effluent streams include methanol, buknol, methyl cellosolve, phenol, and sulfur dioxide.
They are effectively separated from aqueous solutions containing these components.

The X-ray powder diffraction data described above were obtained by standard methods.

Thus, the radiation was a copper Ka double wire.

A Geiger counter spectrometer equipped with a strip-chart pen recorder was also used.

The height of the peak or line and its position (as a function of twice θ) were then read from this spectrometer chart.

From these readings, the relative intensities of the lines or peaks and dl, the interlayer spacing (A) corresponding to the recorded lines, were determined.

Claims (1)

[Claims] 1. A silica polymorph made of crystalline silica and smoked at a humidity of 480 to 1000°C, which
1) Annealing at 0°C for 1 hour. Said silica polymorph having the values shown in Table A below as the six strongest d-values of its X-ray powder diffraction pattern. Table A d-A Relative intensity 11.1±0.2 VS lo, 0±0.2 VS 3.85±0.07 VS 3.82±0.07 8 3.76±0.05 8 3. 72±0.05 8 ("S" in the table - strong, rVsl = very strong) 2 Furthermore, 1.39±0.
Average refractive index of 01 and 1,70±0 at 25°C
．． The silica polymorph according to claim 1 having a specific gravity of 0.05 ji/cc. 3. A method for producing a silica polymorph, the method comprising:
[Here, Q is a formula R, X'' (wherein each R is hydrogen or 2 to 6
150 to 700 mol of water, calculated in terms of the number of moles of oxide, per 1 mole of water, 13 to 50 Mol of amorphous 5102 and O~
6.5 moles of M2O (where M is an alkali metal)
and heating the reaction mixture thus prepared at a temperature of 100 to 250° C. until the formation of a crystalline hydration precursor; Isolate the substance and convert this material to 480
The manufacturing method includes smoking at a temperature of 1000°C to 1000°C. 4 M is sodium, R represents a propyl group,
4. The method of claim 3, wherein X represents nitrogen. 5. In separating organic molecules from a mixture with water, a silica polymorph consisting of crystalline silica and smoked at a humidity of 480 to 1000°C, subjected to baking at 600°C in air for 1 hour. The method of separation comprises contacting the mixture with the silica polymorph having the values shown in Table A below as the six strongest d-values of the extracted X-ray powder diffraction pattern. Table 8d-A Relative intensity 11.1±0.2 VS lo, 0±0.2 VS 3.85±0.07 VS 3.82±0.07 8 3.76±0.05 8 3.72 ±0.05 8 ("S" in the table - strong, IVSj - very strong)" 6 ・
The time-smoked silica polymorph has an average refractive index of 1.39 ± 0.01 and 25° after being smoked at 600°C in air for 1 hour.
6. The method according to claim 5, having a specific gravity of 1,70±0.05 g/cc in C.