A high-viscosity and easily dispersible inorganic gel and preparation method thereof

Abstract

The present application discloses a highly viscous and easily dispersible inorganic gel and a preparation method thereof, and relates to the technical field of inorganic material preparation. The preparation method comprises: taking a purified bentonite slurry, adjusting its pH value to weak acidity, and then performing filter pressing dehydration, and controlling the moisture content of the filter cake after dehydration to be 45% to 50%; adding a modifier to the filter cake for modification and mixing; adding dry powder to the modified material for compounding, and mixing the two uniformly to obtain a compound material; first drying the compound material, and then crushing and sieving, and controlling the product particle size to be 150 mesh to 30 mesh, to obtain a highly viscous and easily dispersible inorganic gel; wherein the dry powder is formed by mixing fine powder less than 150 mesh after sieving with an auxiliary agent. The highly viscous and easily dispersible inorganic gel is made by the preparation method. The preparation method of the highly viscous and easily dispersible inorganic gel of the present application combines the purification of bentonite with the improvement of dispersibility, and the production process is simpler and easier to control and implement.

Description

Technical Field

[0001] The invention relates to the technical field of inorganic material preparation, and in particular to a high-viscosity and easily dispersible inorganic gel and a preparation method thereof. Background Art

[0002] Inorganic gel is a product produced with bentonite or other minerals as the main raw materials. It has good plasticity, adhesion, suspension properties and other characteristics. It is widely used in pesticides, coatings, daily chemicals and other fields.

[0003] The current bentonite inorganic gel products are all in powder form (<100 mesh). Due to the high content of montmorillonite, it is very susceptible to moisture. After being prepared into hydrogel, the viscosity of the slurry is usually high (>1200mPa·s). In addition, when preparing hydrogel, when the powder is put into water, it is very easy to form a mass. The outer layer of the mass is saturated with water and forms a barrier to prevent water from penetrating into the inside, making it difficult for the powder to disperse quickly in water. The mass floats on the water surface due to the large number of gaps inside. Even with high-speed mechanical stirring, it is difficult to disperse it completely. Summary of the invention

[0004] In view of the above-mentioned defects of the prior art, the present invention provides a highly viscous and easily dispersible inorganic gel and a preparation method thereof. By purifying bentonite and then improving its dispersibility, a highly viscous and easily dispersible bentonite inorganic gel can be obtained.

[0005] The technical solution of the present invention is as follows:

[0006] The present application provides a method for preparing a highly viscous and easily dispersible inorganic gel, comprising the following steps:

[0007] Step S1: taking the purified bentonite slurry, adjusting its pH value to weak acidity, and then performing filter pressing to dehydrate, and controlling the moisture content of the filter cake after dehydration to be 45% to 50%;

[0008] Step S2: adding a modifier to the filter cake of step S1 for modification, mixing, and obtaining a modified material;

[0009] Step S3: adding dry powder to the modified material for compounding, and mixing the two evenly to obtain a compound material;

[0010] Step S4: drying the composite material obtained in step S3, crushing and screening the composite material to control the particle size of the product to be 150 mesh to 30 mesh, and finally obtaining the highly viscous and easily dispersible inorganic gel;

[0011] The dry powder in step S3 is formed by mixing the fine powder with a mesh size less than 150 after sieving in step S4 with an auxiliary agent.

[0012] Optionally, the purified bentonite slurry is prepared by the following steps:

[0013] Add bentonite raw materials into water and stir to make slurry, so that the bentonite is fully dispersed and the solid content of the slurry is controlled at 10-20%;

[0014] The dispersed slurry is first screened by a vibrating screener, and the slurry under the screen is then classified by a cyclone, and the overflow is the purified bentonite slurry.

[0015] Optionally, in step S1, the pH value of the purified bentonite slurry is adjusted to 5-6 by using citric acid.

[0016] Optionally, the modifier in step S2 is a mixture of sodium carbonate and sodium bicarbonate in a mass ratio of 1:1.

[0017] Optionally, the amount of the modifier added is 1 wt% to 5 wt% of the filter cake.

[0018] Optionally, in step S3, the mass ratio of the modified material to the dry powder is 1:0.1-0.3.

[0019] Optionally, the auxiliary agent in the dry powder includes a first auxiliary agent and a second auxiliary agent, and the fine powder is first mixed with the first auxiliary agent and then mixed with the second auxiliary agent.

[0020] Optionally, the first auxiliary agent is a combination of one or more of tartaric acid, fumaric acid, and formic acid, and the second auxiliary agent is sodium polyacrylate or acrylamide.

[0021] Optionally, the added amount of the first auxiliary agent is 0.5wt% to 3.0wt% of the fine powder, and the added amount of the second auxiliary agent is 0.1wt% to 1.0wt% of the fine powder.

[0022] The present application also provides a high-viscosity and easily dispersible inorganic gel, which is prepared by the preparation method of the high-viscosity and easily dispersible inorganic gel.

[0023] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0024] (1) The method for preparing the highly viscous and easily dispersible inorganic gel of the present application combines the purification of bentonite with the improvement of dispersibility, making the production process simpler and easier to control and implement;

[0025] (2) The present application reduces the moisture content by adjusting the pH and then using filter pressing, thereby greatly reducing the drying cost; compared with the traditional production process of directly drying the slurry or drying after concentration, the proportion of drying cost in the total cost of the present application is greatly reduced.

[0026] (3) The highly viscous and easily dispersible inorganic gel of the present application has a 5% dispersion viscosity of >3000 mPa·s; it disintegrates rapidly in water without agglomeration, and can be completely dispersed in only 5-7 minutes at a rotation speed of 500 r / min.

[0027] (4) When preparing the dry powder in the present application, the first auxiliary agent and the second auxiliary agent are added separately to the modified material, so as to separate the first auxiliary agent from the modifier to avoid premature reaction between the two.

[0028] (5) In the process of preparing dry powder, the fine powder is first mixed evenly with the first auxiliary agent so that the first auxiliary agent is adsorbed inside the fine powder, and then mixed with the second auxiliary agent. The second auxiliary agent can form a thin film on the surface of the fine powder, which can avoid the reaction between the dry powder and the modified material when they are mixed, and ensure that the dry powder and the modified material react again when dissolved in water, which is conducive to the more uniform dispersion of the inorganic gel in water. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a process flow chart of the preparation method of the highly viscous and easily dispersible inorganic gel of the present application. DETAILED DESCRIPTION

[0030] The present invention will be further described with reference to the accompanying drawings and embodiments:

[0031] Example 1

[0032] Example 1 provides a method for preparing a highly viscous and easily dispersible inorganic gel, comprising the following steps:

[0033] (1) adding bentonite raw materials into water and stirring to make slurry, so that the bentonite is fully dispersed and the solid content of the slurry is controlled at 15%;

[0034] (2) The dispersed slurry is first screened by a vibrating screener with a screen aperture of 325 mesh. The slurry under the screen is then classified by a hydrocyclone. The hydrocyclone adopts the Neptune FX hydrocyclone with the specification of The overflow is the purified bentonite slurry;

[0035] (3) taking the purified bentonite slurry, adjusting its pH value to 5 with citric acid, and then dehydrating by filter pressing, and controlling the moisture content of the filter cake after dehydration to 45%;

[0036] (4) adding 5 wt % of a modifier to the filter cake for modification, and mixing it with a spiral mud mixer to obtain a modified material, wherein the modifier is a mixture of sodium carbonate and sodium bicarbonate in a mass ratio of 1:1;

[0037] (5) adding 0.5 wt % of tartaric acid to the modified material in a mixer while stirring, stirring for 5 min after the addition of tartaric acid, and then adding 0.1 wt % of sodium polyacrylate, and continuing to mix for 5 min to obtain a material;

[0038] (6) The material is first freeze-dried, then crushed and sieved to control the product particle size to 150 mesh to 30 mesh, and finally the highly viscous and easily dispersible inorganic gel is obtained, and fine powder less than 150 mesh is collected.

[0039] Example 2

[0040] Example 2 provides a method for preparing a highly viscous and easily dispersible inorganic gel, comprising the following steps:

[0041] (1) adding bentonite raw materials into water and stirring to make slurry, so that the bentonite is fully dispersed and the solid content of the slurry is controlled at 10%;

[0042] (2) The dispersed slurry is first screened by a vibrating screener with a screen aperture of 325 mesh. The slurry under the screen is then classified by a hydrocyclone. The hydrocyclone adopts the Neptune FX hydrocyclone with the specification of The overflow is the purified bentonite slurry;

[0043] (3) taking the purified bentonite slurry, adjusting its pH value to 6 with citric acid, and then dehydrating by filter pressing, and controlling the moisture content of the filter cake after dehydration to 50%;

[0044] (4) adding 3 wt % of a modifier to the filter cake for modification, and mixing it with a spiral mud mixer to obtain a modified material, wherein the modifier is a mixture of sodium carbonate and sodium bicarbonate in a mass ratio of 1:1;

[0045] (5) adding dry powder to the modified material at a mass ratio of 1:0.2 for compounding, and mixing the two uniformly to obtain a compound material; wherein the dry powder preparation method is: adding 1wt% of fumaric acid to the fine powder less than 150 mesh after sieving in (6) of Example 1 in a high-speed mixer while stirring, stirring for 10 minutes after the addition of fumaric acid, and then adding 1wt% of acrylamide, and continuing to stir for 10 minutes to obtain a dry powder;

[0046] (6) The compounded material is first freeze-dried, then crushed and sieved to control the product particle size to 150 mesh to 30 mesh, and finally the highly viscous and easily dispersible inorganic gel is obtained, and fine powder less than 150 mesh is collected.

[0047] Example 3

[0048] Example 3 provides a method for preparing a highly viscous and easily dispersible inorganic gel, comprising the following steps:

[0049] (1) adding bentonite raw materials into water and stirring to make slurry, so that the bentonite is fully dispersed and the solid content of the slurry is controlled at 20%;

[0050] (2) The dispersed slurry is first screened by a vibrating screener with a screen aperture of 325 mesh. The slurry under the screen is then classified by a hydrocyclone. The hydrocyclone adopts the Neptune FX hydrocyclone with a specification of The overflow is the purified bentonite slurry;

[0051] (3) taking the purified bentonite slurry, adjusting its pH value to 6 with citric acid, and then dehydrating by filter pressing, and controlling the moisture content of the filter cake after dehydration to 48%;

[0052] (4) adding 1 wt % of a modifier to the filter cake for modification, and mixing it with a spiral mud mixer to obtain a modified material, wherein the modifier is a mixture of sodium carbonate and sodium bicarbonate in a mass ratio of 1:1;

[0053] (5) adding dry powder to the modified material at a mass ratio of 1:0.3 for compounding, and mixing the two uniformly to obtain a compound material; wherein the dry powder preparation method is: adding 3wt% of formic acid to the fine powder less than 150 mesh after sieving in (6) of Example 2 in a high-speed mixer while stirring, stirring for 8 minutes after the formic acid is added, and then adding 0.5wt% of sodium polyacrylate, and continuing to stir for 8 minutes to obtain a dry powder;

[0054] (6) The compounded material is first freeze-dried, then crushed and sieved to control the product particle size to 150 mesh to 30 mesh, and finally the highly viscous and easily dispersible inorganic gel is obtained, and fine powder less than 150 mesh is collected.

[0055] Example 4

[0056] Example 4 provides a method for preparing a highly viscous and easily dispersible inorganic gel, comprising the following steps:

[0057] (1) adding bentonite raw materials into water and stirring to make slurry, so that the bentonite is fully dispersed and the solid content of the slurry is controlled at 15%;

[0058] (2) The dispersed slurry is first screened by a vibrating screener with a screen aperture of 325 mesh. The slurry under the screen is then classified by a hydrocyclone. The hydrocyclone adopts the Neptune FX hydrocyclone with a specification of The overflow is the purified bentonite slurry;

[0059] (3) taking the purified bentonite slurry, adjusting its pH value to 5 with citric acid, and then dehydrating by filter pressing, and controlling the moisture content of the filter cake after dehydration to 45%;

[0060] (4) adding 5 wt % of a modifier to the filter cake for modification, and mixing it with a spiral mud mixer to obtain a modified material, wherein the modifier is a mixture of sodium carbonate and sodium bicarbonate in a mass ratio of 1:1;

[0061] (5) adding dry powder to the modified material at a mass ratio of 1:0.1 for compounding, and mixing the two uniformly to obtain a compound material; wherein the dry powder preparation method is: adding 0.5wt% of tartaric acid to the fine powder less than 150 mesh after sieving in (6) of Example 1 in a high-speed mixer while stirring, stirring for 5 minutes after the addition of tartaric acid, and then adding 0.1wt% of acrylamide, and continuing to stir for 5 minutes to obtain a dry powder;

[0062] (6) The compounded material is first freeze-dried, then crushed and sieved to control the product particle size to 150 mesh to 30 mesh, and finally the highly viscous and easily dispersible inorganic gel is obtained, and fine powder less than 150 mesh is collected.

[0063] Example 5

[0064] Example 5 provides a method for preparing a highly viscous and easily dispersible inorganic gel, comprising the following steps:

[0065] (1) adding bentonite raw materials into water and stirring to make slurry, so that the bentonite is fully dispersed and the solid content of the slurry is controlled at 15%;

[0066] (2) The dispersed slurry is first screened by a vibrating screener with a screen aperture of 325 mesh. The slurry under the screen is then classified by a hydrocyclone. The hydrocyclone adopts the Neptune FX hydrocyclone with the specification of The overflow is the purified bentonite slurry;

[0067] (3) taking the purified bentonite slurry, adjusting its pH value to 5 with citric acid, and then dehydrating by filter pressing, and controlling the moisture content of the filter cake after dehydration to 45%;

[0068] (4) adding 5 wt % of a modifier to the filter cake for modification, and mixing it with a spiral mud mixer to obtain a modified material, wherein the modifier is a mixture of sodium carbonate and sodium bicarbonate in a mass ratio of 1:1;

[0069] (5) adding dry powder to the modified material at a mass ratio of 1:0.2 for compounding, and mixing the two uniformly to obtain a compound material; wherein the dry powder preparation method is: adding 0.5wt% of tartaric acid to the fine powder less than 150 mesh after sieving in (6) of Example 1 in a high-speed mixer while stirring, stirring for 5 minutes after the addition of tartaric acid, and then adding 0.1wt% of acrylamide, and continuing to stir for 5 minutes to obtain a dry powder;

[0070] (6) The compounded material is first freeze-dried, then crushed and sieved to control the product particle size to 150 mesh to 30 mesh, and finally the highly viscous and easily dispersible inorganic gel is obtained, and fine powder less than 150 mesh is collected.

[0071] Example 6

[0072] Example 6 provides a method for preparing a highly viscous and easily dispersible inorganic gel, comprising the following steps:

[0073] (1) adding bentonite raw materials into water and stirring to make slurry, so that the bentonite is fully dispersed and the solid content of the slurry is controlled at 15%;

[0074] (2) The dispersed slurry is first screened by a vibrating screener with a screen aperture of 325 mesh. The slurry under the screen is then classified by a hydrocyclone. The hydrocyclone adopts the Neptune FX hydrocyclone with the specification of The overflow is the purified bentonite slurry;

[0075] (3) taking the purified bentonite slurry, adjusting its pH value to 5 with citric acid, and then dehydrating by filter pressing, and controlling the moisture content of the filter cake after dehydration to 45%;

[0076] (4) adding 5 wt % of a modifier to the filter cake for modification, and mixing it with a spiral mud mixer to obtain a modified material, wherein the modifier is a mixture of sodium carbonate and sodium bicarbonate in a mass ratio of 1:1;

[0077] (5) adding dry powder to the modified material at a mass ratio of 1:0.3 for compounding, and mixing the two uniformly to obtain a compound material; wherein the dry powder preparation method is: adding 0.5wt% of tartaric acid to the fine powder less than 150 mesh after sieving in (6) of Example 1 in a high-speed mixer while stirring, stirring for 5 minutes after the addition of tartaric acid, and then adding 0.1wt% of acrylamide, and continuing to stir for 5 minutes to obtain a dry powder;

[0078] (6) The compounded material is first freeze-dried, then crushed and sieved to control the product particle size to 150 mesh to 30 mesh, and finally the highly viscous and easily dispersible inorganic gel is obtained, and fine powder less than 150 mesh is collected.

[0079] The highly viscous and easily dispersible inorganic gels prepared in Examples 1 to 6 were respectively prepared into 5% aqueous suspensions, and the viscosity and dispersion time were tested respectively. The specific test results are shown in Table 1.

[0080] The viscosity test adopts the following method: add 190g of distilled water into a 500ml beaker and place it under a disperser, turn on the stirrer, adjust the speed to 1500r / min, weigh 10g±0.01g of the sample, slowly pour the sample, continue stirring for 7 minutes, and measure the viscosity with a viscometer. When measuring, use a 4﹟ rotor and a speed of 60r / min.

[0081] The dispersion time is tested by the following method: add 297g of distilled water to a 500ml transparent glass beaker, place it on a magnetic stirrer, rotate at 500r / min, weigh 3g±0.01g of the sample, quickly put it into the distilled water, and start timing with a stopwatch. Observe the dispersion until there are no obvious large particles in the beaker, press the stopwatch to record the time used, which is the dispersion time. In addition, move the dispersed suspension to a 100ml stoppered glass measuring cylinder to the 100ml mark, cover the stopper and let it stand for 24h to observe the suspension of the dispersion.

[0082] Table 1

[0083]

[0084] It can be seen from Examples 1-6 that the high-viscosity and easily dispersible inorganic gel prepared by the present application, when prepared into a 1% aqueous dispersion, can be dispersed in only 5-7 minutes at a low speed of 500r / min, indicating that the high-viscosity bentonite inorganic gel prepared by this process solves the problem of high dispersion difficulty. By comparing Example 1 with Examples 4-6, since Examples 4-6 all use the fine powder less than 150 mesh in Example 1 to be pre-dispersed evenly with the first auxiliary agent and the second auxiliary agent, and then compounded with the modified material, it can avoid the first auxiliary agent and the pre-modifier from excessively contacting and reacting; and when the high-viscosity and easily dispersible inorganic gel is prepared into an aqueous dispersion, the first auxiliary agent and the modifier are wetted by water and contacted to react and generate bubbles, which disperse the particles, so that the high-viscosity and easily dispersible inorganic gel is not easy to agglomerate in water and is easier to disperse quickly.

[0085] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a highly viscous and easily dispersible inorganic gel, comprising the following steps: (1) adding bentonite raw materials into water and stirring to make slurry, so that the bentonite is fully dispersed and the solid content of the slurry is controlled at 15%; (2) The dispersed slurry is first screened by a vibrating screening machine with a screen aperture of 325 meshes, and the slurry under the screen is then classified by a cyclone. The cyclone adopts a Neptune FX hydrocyclone, and its specification is that the overflow is the purified bentonite slurry; (3) taking the purified bentonite slurry, adjusting its pH value to 5 with citric acid, and then dehydrating by filter pressing, and controlling the moisture content of the filter cake after dehydration to 45%; (4) adding 5 wt % of a modifier to the filter cake for modification, and mixing it with a spiral mud mixer to obtain a modified material, wherein the modifier is a mixture of sodium carbonate and sodium bicarbonate in a mass ratio of 1:1; (5) adding 0.5 wt% of tartaric acid to the modified material in a mixer while stirring, stirring for 5 minutes after the addition of tartaric acid, and then adding 0.1 wt% of sodium polyacrylate, and continuing to mix for 5 minutes to obtain a material; (6) The material is first freeze-dried, then crushed and sieved to control the product particle size to 150 mesh to 30 mesh, and finally the highly viscous and easily dispersible inorganic gel is obtained, and fine powder less than 150 mesh is collected.

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