CN111573686A - Preparation method of vermiculite ultrafine powder - Google Patents
Preparation method of vermiculite ultrafine powder Download PDFInfo
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- CN111573686A CN111573686A CN202010424343.6A CN202010424343A CN111573686A CN 111573686 A CN111573686 A CN 111573686A CN 202010424343 A CN202010424343 A CN 202010424343A CN 111573686 A CN111573686 A CN 111573686A
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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
- C01B33/20—Silicates
- C01B33/36—Silicates having base-exchange properties but not having molecular sieve properties
- C01B33/38—Layered base-exchange silicates, e.g. clays, micas or alkali metal silicates of kenyaite or magadiite type
- C01B33/42—Micas ; Interstratified clay-mica products
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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
- C01P2004/00—Particle morphology
- C01P2004/60—Particles characterised by their size
- C01P2004/61—Micrometer sized, i.e. from 1-100 micrometer
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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
Abstract
A process for preparing superfine vermiculite powder includes such steps as proportionally dispersing vermiculite clay and magnesium ions in hydrogen peroxide solution, stirring while immersing for a certain time, calcining at a certain temp in muffle furnace for a certain time, cooling, dispersing the sample in aqueous solution, and microwave irradiation. The vermiculite superfine powder prepared by the method is a flaky micron material with the particle size of less than 10 microns, and the preparation method has the advantages of high efficiency, no secondary pollution, strong stability, large-scale production and the like.
Description
Technical Field
The invention relates to the technical field of preparation of micro-nano materials by stripping layered clay minerals, in particular to a preparation method of vermiculite ultrafine powder.
Background
Vermiculite is a clay mineral similar to montmorillonite, is a silicate with a layered structure, and is generally formed by hydrothermally altering or weathering biotite. It sometimes appears as coarse biotite (which is the biotite artifact of vermiculite) and sometimes becomes fine to soil. When vermiculite is heated to 300 ℃, it can expand 20 times and bend. Vermiculite is generally brown, yellow, dark green, has the same gloss as oil, and turns gray after being heated. The vermiculite can be used as building materials, adsorbents, fireproof insulating materials, mechanical lubricants, soil conditioners and the like, and has wide application. The total output of vermiculite in the world in 2000 is over 50 million tons, and the most important producing countries are China, south Africa and the like.
Vermiculite is a complex chemical composition natural water-containing aluminosilicate mineral with the chemical formula of Mgx(H2O){Mg3- x[AlSi O3O10](OH)2}. It is one kind of clay, and its structure can be 3 octahedrons, also can be 2 octahedrons. Typical vermiculite is a 3 octahedral phyllosilicate of type 2:1, i.e. consisting of 2 silicon tetrahedra sandwiching 1 aluminoxy octahedra.
Vermiculite has the characteristics of good interlayer cation exchange capacity, expansion capacity, adsorption capacity, sound insulation, heat insulation, fire resistance, freezing resistance and the like, is stable in chemical property, is insoluble in water, is non-toxic and tasteless, has no side effect, and is mainly used for treating wastewater containing heavy metals and organic cations by utilizing good adsorption performance and ion exchange performance in industry, preparing antibacterial materials and heat insulation materials, vermiculite filter aid, purifying agent, organic vermiculite and the like.
Vermiculite is a layered material, and is expanded to obtain the layered material before practical application. In general, vermiculite is capable of expanding at high temperatures and undergoes swelling in industry. The expanded vermiculite has obvious advantages in wastewater treatment, and is widely applied to water treatment. However, the prepared expanded vermiculite has large particles, small specific surface area, low reaction speed, low regeneration rate and severely limited industrial application. Therefore, the method has important research significance for peeling the expanded vermiculite into the superfine nano-scale powder.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention aims to provide a preparation method of vermiculite ultrafine powder, which can realize effective stripping of vermiculite clay without producing a large amount of unstripped expanded vermiculite and has the advantages of high efficiency, strong stability, clean production process, large-scale industrial production and the like.
In order to achieve the purpose, the invention adopts the technical scheme that:
a preparation method of vermiculite ultrafine powder comprises the following steps:
step 1:
mixing vermiculite clay and magnesium salt according to a mass ratio of 1: (0.1-0.5) adding to 30% H2O2Soaking and stirring (hydrogen peroxide) solution;
step 2:
placing the sample obtained in the step 1 in a muffle furnace for high-temperature calcination, and calcining to obtain a sample;
and step 3:
transferring the sample obtained in the step 2 into a round-bottom flask, adding a certain amount of distilled water with a solid-liquid ratio of 0.1-0.5g/mL, placing the sample into a microwave chemical reactor, cooling and refluxing the sample under a certain microwave power for a certain time, after the reaction is cooled, centrifuging the sample, washing the sample with distilled water, and drying the sample to obtain vermiculite ultrafine powder.
In the step 1, the purity of the vermiculite clay is over 80 percent.
The magnesium salt in the step 1 is one of magnesium chloride, magnesium sulfate and magnesium nitrate.
In the step 1, the solid-to-liquid ratio is 0.05-0.2g/mL, and the mixture is soaked and stirred for 24 hours.
In the step 2, the calcining temperature is 700-900 ℃ and the time is 3-5 h.
The frequency of the microwave chemical reactor in the step 3 is 2.45GHZ, the microwave power in the step 3 is 80-100%, and the microwave reaction time in the step 3 is 30-60 minutes.
The vermiculite ultrafine powder obtained in the step 3 is of a micron sheet structure, the average particle size is less than 10 microns, and the specific surface area exceeds 15m2/g。
The invention has the beneficial effects that:
the vermiculite in the invention is a natural hydrous aluminosilicate clay mineral with complex chemical components, and the typical vermiculite is 3 octahedral lamellar tectosilicate with 2:1 type, namely, the vermiculite is composed of 2 silicon-oxygen tetrahedrons and 1 aluminum-oxygen octahedron sandwiched between the two silicon-oxygen tetrahedrons. The high expansibility is a unique characteristic of vermiculite, and has a multi-stage layered structure, so that the application field of the vermiculite is wider. Before practical application, vermiculite needs to be subjected to stripping pretreatment to prepare expanded vermiculite, so that a multi-level structural material is formed. However, the expanded vermiculite has the disadvantages of large particle size, small specific surface area and the like, so that the application range of the expanded vermiculite is greatly limited, and further stripping and purification are required. The prepared exfoliated vermiculite can obviously increase the specific surface area, improve the utilization efficiency and make the application of the exfoliated vermiculite wider.
According to the invention, multistage stripping means such as hydrogen peroxide soaking, high-temperature calcination, microwave radiation and the like are adopted, so that the effective stripping of vermiculite clay is realized, and the scanning electron microscope photos of the stripped vermiculite show a micron-sized and flaky structure, and the particle size is below 10 microns. The method adopted in the process of peeling the vermiculite has the advantages of high efficiency, no secondary pollution, high peeling purity, large-scale production and the like. At present, although a plurality of methods for stripping vermiculite clay exist, the methods all have advantages and disadvantages, the effective stripping of the vermiculite clay cannot be realized by a single stripping method, and compared with the existing method for stripping vermiculite, the method for stripping vermiculite obviously changes large vermiculite particles into ultrafine powder, and realizes the effective stripping of the vermiculite.
Drawings
FIG. 1 is a Scanning Electron Microscope (SEM) image at low magnification (200 times) of exfoliated vermiculite in the examples.
FIG. 2 is a high magnification (10000 times) Scanning Electron Microscope (SEM) image of exfoliated vermiculite in the example.
Detailed Description
The present invention will be described in further detail with reference to examples.
Example 1:
step 1: 12.5g of vermiculite were weighed as such into a 500mL beaker, and 1.25g of MgCl was added2·6H2O, adding 250ml of 30% H2O2Covering the (hydrogen peroxide) solution with a preservative film, and soaking and stirring the solution on a magnetic stirrer for 24 hours.
Step 2: and (3) drying the sample obtained in the step (1), placing the dried sample in a muffle furnace for high-temperature calcination at 700 ℃ for 5h, and cooling to obtain the sample.
And step 3: transferring the calcined vermiculite sample into a 500mL round-bottom flask, adding 125mL of distilled water, and placing the mixture in a microwave chemical reactor to perform cooling reflux reaction for 30min under 80% microwave power. After the reaction was cooled, the sample was centrifuged, washed with distilled water and dried to obtain a product with a size of about 5 microns, see fig. 1 and 2.
Example 2:
step 1: 50.0g of vermiculite as such was weighed into a 500mL beaker, 25.0g of MgCl was added2·6H2O, adding 250mL of 30% H2O2Covering the (hydrogen peroxide) solution with a preservative film, and soaking and stirring the solution on a magnetic stirrer for 24 hours.
Step 2: and (3) drying the sample obtained in the step (1), placing the dried sample in a muffle furnace for high-temperature calcination at 900 ℃ for 3h, and cooling to obtain the sample.
And step 3: transferring the calcined vermiculite sample into a 500mL round-bottom flask, adding 100mL distilled water, and placing the mixture in a microwave chemical reactor to carry out cooling reflux reaction for 60min under the condition of 100% microwave power. After the reaction is cooled, the sample is centrifuged, washed by distilled water and dried to obtain the product.
Example 3
Step 1: 25.0g of vermiculite as such was weighed into a 500mL beaker, and 5.0g of MgCl was added2·6H2O, adding 250mL of 30% H2O2Covering the (hydrogen peroxide) solution with a preservative film, and soaking and stirring the solution on a magnetic stirrer for 24 hours.
Step 2: and (3) drying the sample obtained in the step (1), placing the dried sample in a muffle furnace for high-temperature calcination at 800 ℃ for 4h, and cooling to obtain the sample.
And step 3: transferring the calcined vermiculite sample into a 500mL round-bottom flask, adding 200mL distilled water, and placing the mixture in a microwave chemical reactor to perform cooling reflux reaction for 40min under 80% microwave power. After the reaction is cooled, the sample is centrifuged, washed by distilled water and dried to obtain the product.
Example 4
Step 1: 50.0g of vermiculite was weighed as such into a 500mL beaker and 10.0g MgSO was added4·7H2O, adding 250mL of 30% H2O2Covering the (hydrogen peroxide) solution with a preservative film, and soaking and stirring the solution on a magnetic stirrer for 24 hours.
Step 2: and (3) drying the sample obtained in the step (1), placing the dried sample in a muffle furnace for high-temperature calcination at 800 ℃ for 4h, and cooling to obtain the sample.
And step 3: transferring the calcined vermiculite sample into a 500mL round-bottom flask, adding 200mL distilled water, and placing the mixture in a microwave chemical reactor to carry out cooling reflux reaction for 30min under the condition of 100% microwave power. After the reaction is cooled, the sample is centrifuged, washed by distilled water and dried to obtain the product.
Example 5
Step 1: 50.0g of vermiculite as such was weighed into a 500mL beaker, 15.0g of Mg (NO) was added3)2·6H2O, adding 250mL of 30% H2O2Covering the (hydrogen peroxide) solution with a preservative film, and soaking and stirring the solution on a magnetic stirrer for 24 hours.
Step 2: and (3) drying the sample obtained in the step (1), placing the dried sample in a muffle furnace for high-temperature calcination at 800 ℃ for 4h, and cooling to obtain the sample.
And step 3: transferring the calcined vermiculite sample into a 500mL round-bottom flask, adding 200mL distilled water, and placing the mixture in a microwave chemical reactor to carry out cooling reflux reaction for 30min under the condition of 100% microwave power. After the reaction is cooled, the sample is centrifuged, washed by distilled water and dried to obtain the product.
The above description is only exemplary of the present invention and should not be taken as limiting, and any modifications, equivalents, improvements, etc. made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (7)
1. A preparation method of vermiculite ultrafine powder is characterized by comprising the following steps:
step 1:
mixing vermiculite clay and magnesium salt according to a mass ratio of 1: (0.1-0.5) adding to 30% H2O2Soaking and stirring (hydrogen peroxide) solution;
step 2:
placing the sample obtained in the step 1 in a muffle furnace for high-temperature calcination to obtain a sample;
and step 3:
transferring the sample obtained in the step 2 into a round-bottom flask, adding a certain amount of distilled water with a solid-liquid ratio of 0.1-0.5g/mL, placing the sample into a microwave chemical reactor, cooling and refluxing the sample under a certain microwave power for a certain time, after the reaction is cooled, centrifuging the sample, washing the sample with distilled water, and drying the sample to obtain vermiculite ultrafine powder.
2. The method for preparing vermiculite ultrafine powder according to claim 1, wherein the purity of vermiculite clay in step 1 is above 80%.
3. The method for preparing vermiculite micropowder according to claim 1, wherein magnesium salt in step 1 is one of magnesium chloride, magnesium sulfate and magnesium nitrate.
4. The method for preparing ultrafine vermiculite powder according to claim 1, wherein the solid-to-liquid ratio in step 1 is 0.05-0.2g/mL, and the mixture is soaked and stirred for 24 h.
5. The process for preparing ultrafine vermiculite powder according to claim 1, wherein the calcination temperature in step 2 is 700 ℃ to 900 ℃ for 3 to 5 hours.
6. The method for preparing vermiculite micropowder according to claim 1, wherein the microwave chemical reactor frequency of step 3 is 2.45GHZ, the microwave power of step 3 is 80% -100%, and the microwave reaction time of step 3 is 30-60 minutes.
7. The method for preparing vermiculite micropowder according to claim 1, wherein the vermiculite micropowder obtained in step 3 has a micron sheet structure, and is flatThe average particle diameter is less than 10 microns, and the specific surface area exceeds 15m2/g。
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115231582A (en) * | 2022-07-19 | 2022-10-25 | 西安交通大学 | Two-dimensional montmorillonite large-size nanosheet stripping method |
| CN117323958A (en) * | 2023-12-01 | 2024-01-02 | 水利部牧区水利科学研究所 | Nanometer adsorption material and preparation method and application thereof |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115231582A (en) * | 2022-07-19 | 2022-10-25 | 西安交通大学 | Two-dimensional montmorillonite large-size nanosheet stripping method |
| CN115231582B (en) * | 2022-07-19 | 2023-12-19 | 西安交通大学 | Two-dimensional montmorillonite large-scale-diameter nano sheet stripping method |
| CN117323958A (en) * | 2023-12-01 | 2024-01-02 | 水利部牧区水利科学研究所 | Nanometer adsorption material and preparation method and application thereof |
| CN117323958B (en) * | 2023-12-01 | 2024-02-13 | 水利部牧区水利科学研究所 | Nanometer adsorption material and preparation method and application thereof |
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