CN108706604A - A kind of wet method prepares method for preparation of modified bentonite - Google Patents

Abstract

The invention belongs to environment conscious material preparing technical fields more particularly to a kind of wet method to prepare method for preparation of modified bentonite.Bentonite material is sorted, remove impurity removing, then it crushes, be sieved, be dissolved in water and suspension is made, modifying agent is added and is sufficiently stirred mixing, then the pH of adjustment mixed liquor is 5~10, modified material is obtained, modified material is washed, filtering, is dehydrated, is dry, is then suppressed in grinding tool, sintering, molding, cooling obtain finished product, wherein carrying out supercharging-decompression operation several times using gas boosting pump while sintering.Present invention process flow is short, production efficiency is high, and raw material is easy to get, is of low cost, and easy to operate, material property is stablized.Finished product itself is nontoxic, harmless, environmentally friendly, suitable for water, the disposition of heavy metal pollution of soil object and solid waste, realizes the target of environmental protection.

Description

A kind of wet method prepares the method for modified bentonite

technical field

The invention belongs to the technical field of preparation of environmental protection materials, in particular to a method for wet preparation of modified bentonite.

Background technique

Bentonite is a natural mineral with montmorillonite as the main component. It has a large specific surface area and has certain adsorption properties. It is also rich in domestic mineral resources and low in price. There are magnesium, potassium, sodium, copper and other cations in the layered structure formed by the montmorillonite unit cell, and the interaction between these cations and the montmorillonite unit cell is not strong, and it is easily replaced by other cations, so it has good ion exchange performance. Bentonite has strong hygroscopicity and can absorb water less than 20 times its own volume and expand to more than 30 times. In water medium, it can be dispersed into a colloidal suspension with certain lubricity, thixotropy and viscosity. It is a natural adsorbent and can be used for the purification of gasoline and kerosene, the removal of edible oil toxins and the treatment of industrial wastewater. Due to the presence of highly hydrophilic and oleophobic groups on the surface of natural bentonite and the hydrolysis of a large number of exchangeable cations between layers, its surface is usually covered by a thin water film, making it unable to effectively adsorb Pollutant molecules in wastewater or soil. If it is directly used in the field of environmental protection such as waste water or solid waste pollutant treatment, the adsorption performance of heavy metal ion exchange adsorption and organic pollutants is relatively poor. Therefore, in order to expand the exchange range of its heavy metal pollution ions and improve the adsorption performance of organic matter, it is necessary to modify the natural bentonite.

Modified bentonite is widely used in chemical industry, electric power, metallurgy, petroleum, electronic devices, mechanical processing and environmental protection. Especially for the treatment of heavy metal pollutants and organic pollutants exceeding the standard of sewage, soil, industrial and agricultural production, and domestic solid waste pollutants, it has attracted more and more people's attention.

In recent years, there have been many patents (authorized patents or published patents) and academic literature on bentonite modification. Modification, Organic Modification, Inorganic Modification, Inorganic/Organic Composite Modification (Research Progress on Modification of Bentonite, Applied Chemical Industry, 2017, 46(4)775-779). Patent Application No. 2014100705591 has disclosed a calcium-based bentonite sodium modification method. Application No. 2014102861109 discloses a filter medium, a filter element and a preparation method for removing phenol in water. Application No. 2015101911891 discloses a compound improver for vanadium-contaminated soil and its preparation method and improvement method. Application No. 2013104435347 discloses a porous material containing NaY zeolite with a high silicon-aluminum ratio and a preparation method thereof. Application No. 2015106353887 discloses a preparation method of bentonite composite material for repairing farmland soil with excessive zinc ions. Application No. 2015101940945 has disclosed a chromium-containing wastewater treatment method and application No. 2006100330702 has disclosed a preparation method and application of a platinum-doped organic nano-titanium pillared clay. The modification methods mentioned in the above literature mainly adopt two ways: dry method modification and wet method modification. No matter which modification method is used, the first purpose is to increase the specific surface area of the material and improve its adsorption capacity; the second is to increase its ion exchange capacity, especially the adsorption and exchange capacity of heavy metal ions.

The existing dry modification and wet modification have their own advantages and disadvantages. The advantages of dry modification are obvious, including that the modifier does not need to have good water solubility, no dehydration drying operation saves time, and the recovery rate is relatively high and nearly 100%. Therefore, the manufacturing cost of the material is lower. However, due to the dry modification operation, the ion adsorption and exchange capacity is relatively poor because the contact between bentonite and the modifier is not as sufficient as the wet modification operation.

Compared with dry modification, wet modification usually adopts aqueous solution to add various modifiers, and then performs operations such as stirring, pillar support and ion exchange, dehydration and drying. The advantage is that the modifier can fully contact with the bentonite, the performance of the bentonite is better modified, and the adsorption capacity and ion exchange capacity are improved. However, its specific surface area and ion exchange capacity increase are limited, the recovery rate of modified bentonite is low, and the manufacturing cost of materials is relatively high.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for wet preparation of modified bentonite. Further improve the specific surface area of the bentonite modified material, increase its adsorption capacity and ion exchange capacity, and reduce the use cost.

The present invention is achieved like this:

A method for preparing modified bentonite by a wet method, characterized in that: sorting bentonite raw materials, removing impurities, then pulverizing, sieving, adding water to dissolve to form a suspension, adding modifiers to fully stir and mix, and then adjusting The pH of the mixed liquid is 5-10, and the modified material is obtained. The modified material is washed, filtered, dehydrated, dried, and then pressed in a grinding tool, sintered, formed, and cooled to obtain a finished product. Gas pressurization is used during sintering The pump performs at least one pressurization-depressurization operation;

The modifying agent includes: sodiumizing agent, pillaring agent, surfactant, magnetic material, nano photocatalyst, pore forming agent and structure optimizing agent. After adding a modifying agent, mechanical stirring is required for 2 to 10 minutes. hours, mix well.

The gas used by the gas booster pump is nitrogen or argon.

further:

For the sintering, the temperature is raised to a sintering temperature of 400-550°C at a heating rate of 5°C/min. While the temperature is rising, a gas booster pump is used to pressurize to 2-20MPa, and then depressurize to 0.1-0.8MPa, and maintain The corresponding pressure is 5-20 minutes, and the pressurization-decompression operation is repeated 1-3 times. After the pressurization-decompression operation is completed, the sintering temperature is kept at 400-550° C. and the sintering time is 1-8 hours.

The bentonite raw material includes calcium-based or sodium-based bentonite, and also includes silicon-aluminum minerals.

The sodiumizing agent is added according to the weight percentage of 0.1% to 10%, including sodium carbonate, sodium bicarbonate, sodium chloride, sodium sulfate, sodium acetate, sodium phosphate, sodium monohydrogen phosphate, sodium dihydrogen phosphate One or a combination of two or more.

The propping agent is added at 1% to 30% by mass, and includes one or more combinations of polyaluminum-containing aluminum chlorohydrate, aluminum carbonate, aluminum sulfate hydrate, and aluminum phosphate.

The magnetic material is added according to 0.5%-5% by mass, including ferric chloride hydrate, ferric sulfate, and ferric carbonate.

The surfactant is added according to 0.01% to 5% by mass percentage, including one or more combinations of cationic surfactants, anionic surfactants, amphoteric surfactants and nonionic surfactants; the cationic Surfactant comprises short medium chain quaternary ammonium compound, described anionic surfactant comprises linear alkylbenzene sulfonate sodium, described amphoteric surfactant comprises lecithin, amino acid type or betaine type, and described nonionic surfactant Agents include alkyl glucoside APG, fatty acid glycerides, fatty acid sorbitan or polysorbate.

The pore forming agent is added according to 1% to 20% by mass, and includes one or more combinations of activated carbon, starch, sawdust, peat, lignite, weathered coal, humic acid and polychitosan.

The structure optimizer is added at a mass percentage of 0.5% to 5%, including polyvinyl alcohol and polyethyleneimine.

The nano photocatalyst is TiO ₂ , and the mass percentage added is 0.1%-5%.

Using spray technology, the finished product is sprayed with a complexing agent, then dried and cooled to obtain the final product; the complexing agent includes ethylenediaminetetraacetic acid EDTA, cyclohexanediaminetetraacetic acid CyDTA, ethylene glycol diethyl ether diethyl ether EGTA, or a salt thereof. The mass percentage added is 0.01%-1%.

The invention has the advantages that: the process flow of the method is simple and convenient to operate, and the conditions are easy to control. The finished product itself is non-toxic, harmless and environmentally friendly. The finished product is recycled and reused by magnetic separation, and the use cost is low. The disposal of pollutants in water or soil is easy to operate, the treatment effect is good, and the goal of environmental protection is achieved.

details as follows:

(1) Add appropriate amount of modifiers such as sodium agent, propping agent, pore forming agent, etc. The purpose is to further increase its specific surface area, increase its adsorption capacity and ion exchange capacity. (2) Add an appropriate amount of nano-photocatalyst to make it have photocatalytic redox characteristics, and expand its treatment range for organic matter and reducing pollutants; (3) Gas booster pump pressurization-decompression operation to further improve the bentonite modified material Specific surface area, increase its adsorption capacity and ion exchange capacity; (4) Use the spray method to spray complexing agents such as EDTA to improve the selectivity of its adsorption of heavy metal pollutants; (5) Add magnetic materials, and the modified materials are recovered by magnetic separation , Sintering regeneration treatment, reuse, prolong the service life, reduce the cost of use, and reduce the secondary pollution caused to the natural environment.

Description of drawings

The present invention will be further described below in conjunction with the embodiments with reference to the accompanying drawings.

Fig. 1 is a flow chart of the execution of the method of the present invention.

Detailed ways

A method for wet preparation of modified bentonite, specifically comprising the steps of:

Step 1: Preparation of bentonite raw material A: The mined raw material is simply manually selected, stones and other mechanical impurities are removed, crushed by a jaw crusher or a ball mill, and the particle size is 100 mesh to 200 mesh, and the bentonite raw material A is obtained.

Step 2: Preparation of bentonite raw material slurry B: Add raw material A according to 10% to 30% by mass percentage in 500mL water to obtain slurry B.

Step 3: In slurry B, add modifier and mix evenly under 10-80°C, 200-400r/min stirring conditions. Add each modifier in the modifier order listed below. (1) Sodium-based modifier. The sodium-based modifier for industrial use is added according to the mass percentage wt of 0.1% to 10%. (2) 1% to 30% propping agent. (3) 0.01% to 5% surfactant. (4) 0.5% to 5% magnetic material. (5) 5% to 10% nanometer photocatalyst TiO2. (6) 1% to 20% pore forming agent. (7) 0.5% to 5% structure optimizer. After each modifier is added, mechanical stirring is required for 2 to 10 hours to mix evenly.

Step 4: Use hydrochloric acid (1+1, volume ratio) and sodium hydroxide (20%, mass percent) to adjust the pH of the suspension to 5-10, stir evenly, and obtain modified slurry C.

Step 5: After slurry C is washed, vacuum filtered, dehydrated and dried, powder modified dry material D is obtained.

Step 6: At a heating rate of 5°C/min, the high-temperature furnace is heated from room temperature to a sintering temperature of 400-550°C. At the same time as the temperature rises, use the pneumatic booster pump pressurization-decompression technology to carry out nitrogen/argon pressurization (2-20MPa)-decompression (0.1-0.8MPa) hole expansion operation and maintain the corresponding high pressure and low pressure 5 ~20min, repeat pressurization-decompression operation to increase its porosity and increase its specific surface area. Keep the sintering temperature at 400-550° C. and the sintering time for 1-8 hours, and cool naturally to room temperature to obtain the finished product E.

Step 7: Mechanically crush the finished product E to obtain powder modified finished product F (100-300 meshes); the following different finished products are obtained from different molding abrasives: granulated finished product G (particle size < 1 mm), rod-shaped finished product H (size <1mm×5cm) and block finished product I size<5cm×5cm).

Step 8: Spray complexing agent EDTA etc. (mass percentage 0.01%-1%) on the powder finished product F/granule finished product G/rod-shaped finished product H/block-shaped finished product I by spraying technology.

Step Nine: Dry the finished product. Dry each of the above-mentioned finished products for 1-5 hours, and cool to room temperature to obtain the final product: powder product K/granule product L/rod product M/block product N.

After using the final finished product to dispose of pollutants, sort and recycle the bentonite waste, then crush (no more than 200 mesh), magnetically separate, and then repeat the above steps 4 to 7 to regenerate and reuse the bentonite waste.

further:

In addition to calcium-based or sodium-based bentonite, the raw materials also include silicon-aluminum minerals such as kaolin, bauxite, and diatomaceous earth.

The sodium-based modifier can be one kind or a combination of two or more sodium-based modifiers. Including sodium carbonate, sodium bicarbonate, sodium chloride, sodium sulfate, sodium acetate, sodium phosphate, sodium monohydrogen phosphate, sodium dihydrogen phosphate, etc.

The proppant can be one kind or a combination of two or more kinds of proppant. Such as aluminum chlorohydrate [containing polyaluminum, Al ₂ (OH) nCl _6-n ], aluminum carbonate, aluminum sulfate hydrate, aluminum phosphate.

The magnetic material includes ferric chloride hydrate, ferric sulfate, ferric carbonate and the like.

The nano photocatalyst TiO ₂ is prepared by applying the method of patent application number 200910111090.0 to prepare the nano material. The mass percentage added is 0.1%-5%.

The surfactant includes one or more combinations of cationic surfactants, anionic surfactants, amphoteric surfactants and nonionic surfactants. The total amount of surfactant added is 0.01%-5% by mass. Cationic surfactants include short and medium chain quaternary ammonium compounds, anionic surfactants include sodium linear alkylbenzene sulfonate, amphoteric surfactants include lecithin, amino acid type and betaine type and nonionic surfactants include alkyl glucose Glycosides (APG), fatty acid glycerides, fatty acid sorbitan (Span) and polysorbate (Tween).

Cationic surfactants are mainly used for cationic inorganic pollutants or organic substances with positive charges; anionic surfactants are mainly used for anionic inorganic pollutants or organic substances with negative charges; amphoteric surfactants are used for cationic inorganic pollutants Pollutants or positively charged organics are used in turn for anionic inorganic pollutants or negatively charged organics.

The pore forming agent can be one type or a combination of two or more pore forming agents. Including activated carbon powder, activated carbon granules, starch, sawdust, peat, lignite, weathered coal, humic acid, polychitosan. According to the strength, porosity, density, adsorption capacity, specific surface area and other indicators of the modified bentonite material, add the corresponding pore-forming agent. The amount of each pore-forming agent is controlled to be no more than 1% to 20% by mass.

The structure optimizer includes polyvinyl alcohol, polyethyleneimine and the like.

The complexing agent includes ethylenediaminetetraacetic acid (EDTA), cyclohexanediaminetetraacetic acid (CyDTA), ethylene glycol diethyl ether diaminetetraacetic acid (EGTA) and their salts.

Implementation Mode 1

Step 1: The mined raw materials are simply manually selected, stones and other mechanical impurities are removed, crushed by a jaw crusher or a ball mill, and the particle size is 100 mesh to 200 mesh, and the raw material A of bentonite is obtained.

Step 2: preparation of bentonite slurry B. 500mL of water, according to the mass percentage of 10% to 30%, add the raw material A to obtain the slurry B.

Step 3: In the slurry B, mix evenly at 10-80°C and 200-400r/min stirring conditions. Add each modifier in the following modifier order:

Sodium carbonate is selected as the sodium-based modifier for industrial use, and is added according to the mass percentage wt of 0.1% to 10%.

1% to 30% of the propping agent is selected from aluminum chloride hydrate [containing polyaluminum, Al ₂ (OH)nCl _6-n ].

0.01% to 5% surfactant, the cationic surfactant hexadecyltrimethylammonium bromide is selected.

0.5% to 5% magnetic material, ferric chloride hydrate.

5% to 10% nanometer photocatalyst TiO ₂ .

1% to 20% of the pore-forming agent is activated carbon powder.

0.5% to 5% structure optimizer uses polyvinyl alcohol.

After each modifier is added, mechanical stirring is required for 2 to 10 hours to mix evenly.

Step 4: Use hydrochloric acid (1+1, volume ratio) and sodium hydroxide (20%, mass percent) to adjust the pH of the suspension to 5-10, stir evenly, and obtain modified slurry C.

Step 5: After slurry C is washed, vacuum filtered, dehydrated and dried, powder modified dry material D is obtained.

Step 6: pressurization-decompression operation dry material D. With a heating rate of 5°C/min, the high-temperature furnace is heated from room temperature to a sintering temperature of 400-550°C.

At the same time as the temperature rises, use the pneumatic booster pump pressurization-decompression technology to carry out nitrogen/argon pressurization (2-20MPa)-decompression (0.1-0.8MPa) hole expansion operation and maintain the corresponding high pressure and low pressure 5 ~20min, repeat pressurization-decompression operation to increase its porosity and increase its specific surface area. Keep the sintering temperature at 400-550° C. and the sintering time for 1-8 hours, and cool naturally to room temperature to obtain the finished product E.

Step 7: Mechanically crush the finished product E to obtain powder modified finished product F (100-300 meshes); the following different finished products are obtained from different molding abrasives: granulated finished product G (particle size < 1 mm), rod-shaped finished product H (size <1mm×5cm) and block finished product I size<5cm×5cm).

Step 8: Spray complexing agent EDTA (0.01%-1% by mass) on the powder finished product F/granule finished product G/rod-shaped finished product H/block-shaped finished product I by spraying technology.

Step Nine: Dry the finished product. Dry each finished product in the above step 8 for 1-5 hours, and cool to room temperature to obtain the final product: powder product K/granule product L/rod product M/block product N.

Step 10: Sorting, recycling, crushing (no more than 200 meshes) and magnetic separation of the bentonite waste after disposal of pollutants, and then repeating the above steps 4 to 7 to regenerate and reuse the bentonite waste.

Implementation mode two

Step 1: The mined raw materials are simply manually selected, stones and other mechanical impurities are removed, crushed by a jaw crusher or a ball mill, and the particle size is 100 mesh to 200 mesh, and the raw material A of bentonite is obtained.

Step 2: preparation of bentonite slurry B. 500mL of water, according to the mass percentage of 10% to 30%, add the raw material A to obtain the slurry B.

Step 3: In the slurry B, mix evenly at 10-80°C and 200-400r/min stirring conditions. Add each modifier in the following modifier order:

Sodium chloride is selected as the sodium-based modifier for industrial use, and is added according to the weight percentage of 0.1% to 10%.

1% to 30% of the propping agent is selected from aluminum chloride hydrate [containing polyaluminum, Al ₂ (OH)nCl _6-n ].

The total amount of surfactant is controlled at 0.01% to 5%, and the cationic and anionic surfactant mixture cetyltrimethylammonium bromide and polyacrylamide (1:1) are selected.

0.5% to 5% magnetic material, ferric chloride hydrate.

5% to 10% nanometer photocatalyst TiO ₂ .

1% to 20% of the porosity agent is polychitosan.

0.5% to 5% structure optimizer uses polyvinyl alcohol.

After each modifier is added, mechanical stirring is required for 2 to 10 hours to mix evenly.

Step 4: Use hydrochloric acid (1+1, volume ratio) and sodium hydroxide (20%, mass percent) to adjust the pH of the suspension to 5-10, stir evenly, and obtain modified slurry C.

Step 5: After slurry C is washed, vacuum filtered, dehydrated and dried, powder modified dry material D is obtained.

Step 6: pressurization-decompression operation dry material D. With a heating rate of 5°C/min, the high-temperature furnace is heated from room temperature to a sintering temperature of 400-550°C.

At the same time as the temperature rises, use the pneumatic booster pump pressurization-decompression technology to carry out nitrogen/argon pressurization (2-20MPa)-decompression (0.1-0.8MPa) hole expansion operation and maintain the corresponding high pressure and low pressure 5 ~20min, repeat pressurization-decompression operation to increase its porosity and increase its specific surface area. Keep the sintering temperature at 400-550° C. and the sintering time for 1-8 hours, and cool naturally to room temperature to obtain the finished product E.

Step 7: Mechanically crush the finished product E to obtain powder modified finished product F (100-300 meshes); the following different finished products are obtained from different molding abrasives: granulated finished product G (particle size < 1 mm), rod-shaped finished product H (size <1mm×5cm) and block finished product I size<5cm×5cm).

Step 8: Spray complexing agent EDTA (0.01%-1% by mass) on the powder finished product F/granule finished product G/rod-shaped finished product H/block-shaped finished product I by spraying technology.

Step Nine: Dry the finished product. Dry each finished product in the above step 8 for 1-5 hours, and cool to room temperature to obtain the final product: powder product K/granule product L/rod product M/block product N.

Step 10: Sorting, recycling, crushing (no more than 200 meshes) and magnetic separation of the bentonite waste after disposal of pollutants, and then repeating the above steps 4 to 7 to regenerate and reuse the bentonite waste.

Implementation Mode Three

Step 1: The mined raw materials are simply manually selected, stones and other mechanical impurities are removed, crushed by a jaw crusher or a ball mill, and the particle size is 100 mesh to 200 mesh, and the raw material A of bentonite is obtained.

Step 2: preparation of bentonite slurry B. 500mL of water, according to the mass percentage of 10% to 30%, add the raw material A to obtain the slurry B.

Step 3: In the slurry B, mix evenly at 10-80°C and 200-400r/min stirring conditions. Add each modifier in the following modifier order:

Sodium carbonate and sodium bicarbonate are selected as the sodium-based modifier for industrial use, and are added according to the total mass percentage of 0.1% to 10%.

1% to 30% of the proppant is selected from aluminum chloride hydrate [containing polyaluminum, Al ₂ (OH)nCl _6-n ].

0.01% to 5% surfactant, choose hexadecyltrimethylammonium bromide and polyethyleneimine.

The total amount is controlled at 0.5% to 5% magnetic material, ferric chloride hydrate and ferrous chloride (1:1).

5% to 10% nanometer photocatalyst TiO ₂ .

The total amount is 1% to 20% pore forming agent, and activated carbon powder and polychitosan (2:1) are selected.

0.5% to 5% structure optimizer uses polyvinyl alcohol.

After each modifier is added, mechanical stirring is required for 2 to 10 hours to mix evenly.

Step 4: Use hydrochloric acid (1+1, volume ratio) and sodium hydroxide (20%, mass percent) to adjust the pH of the suspension to 5-10, stir evenly, and obtain modified slurry C.

Step 5: After slurry C is washed, vacuum filtered, dehydrated and dried, powder modified dry material D is obtained.

Step 6: pressurization-decompression operation dry material D. With a heating rate of 5°C/min, the high-temperature furnace is heated from room temperature to a sintering temperature of 400-550°C.

At the same time as the temperature rises, use the pneumatic booster pump pressurization-decompression technology to carry out nitrogen/argon pressurization (2-20MPa)-decompression (0.1-0.8MPa) hole expansion operation and maintain the corresponding high pressure and low pressure 5 ~20min, repeat pressurization-decompression operation to increase its porosity and increase its specific surface area. Keep the sintering temperature at 400-550° C. and the sintering time for 1-8 hours, and cool naturally to room temperature to obtain the finished product E.

Step 7: Mechanically crush the finished product E to obtain powder modified finished product F (100-300 meshes); the following different finished products are obtained from different molding abrasives: granulated finished product G (particle size < 1 mm), rod-shaped finished product H (size <1mm×5cm) and block finished product I size<5cm×5cm).

Step 8: Spray complexing agent EDTA (0.01%-1% by mass) on the powder finished product F/granule finished product G/rod-shaped finished product H/block-shaped finished product I by spraying technology.

Step Nine: Dry the finished product. Dry each finished product in the above step 8 for 1-5 hours, and cool to room temperature to obtain the final product: powder product K/granule product L/rod product M/block product N.

Step 10: Sorting, recycling, crushing (no more than 200 meshes) and magnetic separation of the bentonite waste after disposal of pollutants, and then repeating the above steps 4 to 7 to regenerate and reuse the bentonite waste.

Implementation Mode Four

Step 1: The mined raw materials are simply manually selected, stones and other mechanical impurities are removed, crushed by a jaw crusher or a ball mill, and the particle size is 100 mesh to 200 mesh, and the raw material A of bentonite is obtained.

Step 2: preparation of bentonite slurry B. 500mL of water, according to the mass percentage of 10% to 30%, add the raw material A to obtain the slurry B.

Step 3: In the slurry B, mix evenly at 10-80°C and 200-400r/min stirring conditions. Add each modifier in the following modifier order:

The sodium-based modifier for industrial use is sodium chloride, which is added according to the total mass percentage of 0.1% to 10%.

1% to 30% of the proppant is selected from aluminum chloride hydrate [containing polyaluminum, Al ₂ (OH)nCl _6-n ].

0.01% to 5% surfactant, choose cetyltrimethylammonium bromide, polyethyleneimine and polysorbate.

The total amount is controlled at 0.5% to 5% magnetic material, ferric chloride hydrate and ferrous chloride (1:1).

5% to 10% nanometer photocatalyst TiO ₂ .

The total amount is 1% to 20% pore forming agent, and activated carbon powder and polychitosan (2:1) are selected.

0.5% to 5% structure optimizer uses polyvinyl alcohol.

After each modifier is added, mechanical stirring is required for 2 to 10 hours to mix evenly.

Step 4: Use hydrochloric acid (1+1, volume ratio) and sodium hydroxide (20%, mass percent) to adjust the pH of the suspension to 5-10, stir evenly, and obtain modified slurry C.

Step 5: After slurry C is washed, vacuum filtered, dehydrated and dried, powder modified dry material D is obtained.

Step 6: pressurization-decompression operation dry material D. With a heating rate of 5°C/min, the high-temperature furnace is heated from room temperature to a sintering temperature of 400-550°C.

At the same time as the temperature rises, use the pneumatic booster pump pressurization-decompression technology to carry out nitrogen/argon pressurization (2-20MPa)-decompression (0.1-0.8MPa) hole expansion operation and maintain the corresponding high pressure and low pressure 5 ~20min, repeat pressurization-decompression operation to increase its porosity and increase its specific surface area. Keep the sintering temperature at 400-550° C. and the sintering time for 1-8 hours, and cool naturally to room temperature to obtain the finished product E.

Step 7: Mechanically crush the finished product E to obtain powder modified finished product F (100-300 meshes); the following different finished products are obtained from different molding abrasives: granulated finished product G (particle size < 1 mm), rod-shaped finished product H (size <1mm×5cm) and block finished product I size<5cm×5cm).

Step 8: Spray complexing agent EDTA (0.01%-1% by mass) on the powder finished product F/granule finished product G/rod-shaped finished product H/block-shaped finished product I by spraying technology.

Step Nine: Dry the finished product. Dry each finished product in the above step 8 for 1-5 hours, and cool to room temperature to obtain the final product: powder product K/granule product L/rod product M/block product N.

Step 10: Sorting, recycling, crushing (no more than 200 meshes) and magnetic separation of the bentonite waste after disposal of pollutants, and then repeating the above steps 4 to 7 to regenerate and reuse the bentonite waste.

Although the specific embodiments of the present invention have been described above, those skilled in the art should understand that the specific embodiments we have described are only illustrative, rather than used to limit the scope of the present invention. Equivalent modifications and changes made by skilled personnel in accordance with the spirit of the present invention shall fall within the protection scope of the claims of the present invention.

Claims (10)

1. a kind of wet method prepares method for preparation of modified bentonite, it is characterised in that：Bentonite material is sorted, impurity removing is removed, Then it crushes, be sieved, be dissolved in water and suspension is made, modifying agent is added and is sufficiently stirred mixing, the pH for then adjusting mixed liquor is 5 ~10, modified material is obtained, modified material is washed, filtering, is dehydrated, is dry, is then suppressed in grinding tool, is sintered, is molded, is cold But finished product is obtained, wherein carrying out supercharging-decompression operation at least once using gas boosting pump while sintering；

The modifying agent includes：Sodium agent, column-supporting agent, surfactant, magnetic material, nano-photocatalyst, gas generation agent and Structure optimization agent is both needed to mechanical agitation 2~10 hours after a kind of modifying agent is often added, and is uniformly mixed.

2. wet method according to claim 1 prepares method for preparation of modified bentonite, it is characterised in that：The sintering, with 5 DEG C/ Min heating rates are warming up to 400~550 DEG C of sintering temperature, while heating, be pressurized to 2 using gas boosting pump~ 20MPa, is then decompressed to the operation of 0.1~0.8MPa, and keeps 5~20min of the relevant pressure, repeats supercharging-decompression operation 1 ~3 times, supercharging-decompression operation terminates, and keeps 400~550 DEG C of sintering temperature, 1~8h of sintering time.

3. wet method according to claim 1 prepares method for preparation of modified bentonite, it is characterised in that the bentonite material packet Calcium base or sodium bentonite are included, further includes siulica-alumina mineral.

4. wet method according to claim 1 prepares method for preparation of modified bentonite, it is characterised in that the sodium agent, according to Mass percent wt 0.1%~10% add, including sodium carbonate, sodium bicarbonate, sodium chloride, sodium sulphate, sodium acetate, sodium phosphate, One or more of disodium-hydrogen, sodium dihydrogen phosphate combine.

5. wet method according to claim 1 prepares method for preparation of modified bentonite, it is characterised in that the column-supporting agent, according to Mass percent 1%~30% is added, and includes one in aluminium chlorohydrate containing poly-aluminium, aluminium carbonate, hydrazine aluminum sulfate, aluminum phosphate Kind or two or more combinations.

6. wet method according to claim 1 prepares method for preparation of modified bentonite, it is characterised in that the magnetic material is pressed It is added according to mass percent 0.5%~5%, including Ferric Chloride Hydrated, ferric sulfate, ferric carbonate.

7. wet method according to claim 1 prepares method for preparation of modified bentonite, it is characterised in that the surfactant is pressed It is added according to mass percent 0.01%~5%, including cationic surfactant, anion surfactant, amphoteric surface's work Property one or more of agent and nonionic surfactant combination；The cationic surfactant includes brachymedial chain season Ammonium compound, the anion surfactant include sodium n-alkylbenzenesulfonate, the amphoteric surfactant include lecithin, Amino acid pattern or betaine type, the nonionic surfactant include alkyl-glucoside APG, fatty glyceride, fat Sour sorb is smooth or poly- sorb fat.

8. wet method according to claim 1 prepares method for preparation of modified bentonite, it is characterised in that the gas generation agent, according to Mass percent 1%~20% is added, including activated carbon, starch, saw dust, peat, lignite, weathered coal, humic acid, Chitosan One or more of combination.

9. wet method according to claim 1 prepares method for preparation of modified bentonite, it is characterised in that the structure optimization agent, It is added according to mass percent 0.5%~5%, including polyvinyl alcohol, polyethyleneimine.

10. wet method according to claim 1 prepares method for preparation of modified bentonite, it is characterised in that spray technique is used, it is right The finished product sprays complexing agent, then dry, cooling, obtains final products；The complexing agent include edta edta, Cyclohexanediamine tetraacetic acid CyDTA, ethylene glycol diethyl ether ethylenediamine tetraacetic acid (EDTA) EGTA or its salt.