CN110819402A

CN110819402A - Starch modified comb-type coal water slurry dispersing agent and preparation method thereof

Info

Publication number: CN110819402A
Application number: CN201911135395.5A
Authority: CN
Inventors: 董翠平; 马丽涛; 彭城; 尤健健; 杨道顺
Original assignee: Anhui Xin Solid Environmental Co Ltd
Current assignee: Anhui Xin Solid Environmental Co Ltd
Priority date: 2019-11-19
Filing date: 2019-11-19
Publication date: 2020-02-21

Abstract

The invention provides a starch modified comb-type coal water slurry dispersing agent and a preparation method thereof, wherein the coal water slurry dispersing agent is prepared from the following raw materials in parts by weight: 20-80 parts of starch; 15-35 parts of 32% sodium hydroxide solution; 5-25 parts of sodium sulfite; 5-15 parts of acetic acid; 2-7 parts of 27% hydrogen peroxide; 470 portions of deionized water and 550 portions; 0.5-1.5 parts of 3-mercaptopropionic acid; polyethylene glycol monomethyl ether 200-800180-300 parts; 0.5-2 parts of VC; 20-35 parts of acrylic acid; 5-10 parts of hydroxyethyl ester. The coal water slurry dispersing agent prepared by the invention has low production cost and wide raw material sources, can act on the coal water slurry alone to play a good dispersing effect, and can greatly improve the dispersing effect, the adaptability and the stability of the product when being used after being compounded with other dispersing agents, sodium carbonate and the like according to a certain proportion compared with the single use.

Description

Starch modified comb-type coal water slurry dispersing agent and preparation method thereof

Technical Field

The invention relates to the technical field of coal water slurry dispersing agents, and particularly relates to a starch modified comb-type coal water slurry dispersing agent and a preparation method thereof.

Background

In the petroleum crisis in the world, new energy substitutes are researched, and coal water slurry is one of the substitutes. The coal water slurry is produced in the international oil crisis period at the end of the 70 s in the 21 st century, is a high and new technology product for planning to replace petroleum and utilizing coal, and mainly comprises about 60-70% of coal, about 30-40% of water and a small amount of water coal slurry additive, has good fluidity and stability, and has an appearance similar to that of heavy oil. The coal water slurry technology is characterized in that solid coal is converted into liquid coal-based fuel through a physical process, and the liquid coal-based fuel has good combustion characteristics and partial advantages of heavy oil, so that the solid coal-based fuel can be applied to industries such as power generation and the like instead of the heavy oil, and the coal water slurry is a novel clean fuel for replacing oil, which is simple in preparation process, easy to transport and store, safe and reliable in general.

Since the advent, coal water slurries have found widespread use in western developed countries. In recent years, many researches are made on coal water slurry additives at home and abroad, and a series of competitive products are produced. The research and application of the coal water slurry dispersing agent are prominent in foreign Nippon grease company, Kao corporation, and Across corporation. A series of good dispersants such as sodium polystyrene sulfonate (PSS), naphthalene sulfonate polymer (NSF), etc. have been developed by japanese researchers and have been used in industrial production. The national brewing company of America synthesizes a nonionic dispersant as the water-coal-slurry dispersant, which can lead the concentration of the prepared water-coal-slurry to reach 70 percent and has ideal stability and fluidity. The coal water slurry NDF dispersant developed by Nanjing university at home is suitable for wide coal types and has good performance. The water coal slurry additive synthesized by Kunzhan fine chemical company of Kunzhan city, Jiangsu province has certain performance even exceeding that of similar Japanese products. HNF developed by Huainan mining group synthetic material Limited liability company can simultaneously give consideration to the dispersibility and stability of the coal water slurry. The total amount of coal resources in China is rich, the resource reserves of coal in China are 15663.1 hundred million tons, and the low-rank coal accounts for more than 50 percent. In the existing pulping technology, low-rank coal is difficult to prepare high-concentration coal water slurry. And the dispersant used for the coal water slurry mainly comprises naphthalene series, lignin series, humic acid series, sulfonated acetone-formaldehyde condensate, nonionic dispersant and the like. However, most of these dispersants are produced from petroleum products, which are expensive and easily cause environmental pollution. And the pulp concentration of the coal is not high, and the pulp concentration of the coal is between 59 and 61 by using low-rank coal and immature coal generally.

The research of the coal water slurry additive as one of the important raw materials of the coal water slurry technology is bound to become the research and development direction of China, and the production and use cost of the coal water slurry additive is higher at present, so that the search and development of a synthetic method of a novel coal water slurry dispersant and a synthetic raw material of the novel coal water slurry dispersant have positive significance for promoting the leap-type development of the coal water slurry technology of China.

The starch is a nontoxic, pollution-free, non-irritant and renewable surfactant, contains more active groups such as hydroxyl groups and the like, and has high yield and low price in China. Therefore, the modified graft is grafted to the main chain of the comb type coal water slurry dispersant to replace partial monomer ether, so that the use amount of the monomer can be reduced, a large number of active groups are introduced, and the good surface activity effect is achieved, thereby not only providing sufficient new raw materials for synthesizing the comb type coal water slurry dispersant, but also exploring a new method for synthesizing the coal water slurry dispersant.

Disclosure of Invention

The invention aims to provide a starch modified comb-type coal water slurry dispersing agent and a preparation method thereof, the prepared coal water slurry dispersing agent has low production cost and wide raw material sources, can act on coal water slurry alone to play a good dispersing effect, and can greatly improve the dispersing effect, the adaptability and the stability of products when being used after being compounded with other dispersing agents, sodium carbonate and the like according to a certain proportion compared with the single use.

In order to achieve the purpose, the invention is realized by the following technical scheme:

a starch modified comb-type coal water slurry dispersing agent is prepared from the following raw materials in parts by weight: 20-80 parts of starch; 15-35 parts of 32% sodium hydroxide solution; 5-25 parts of sodium sulfite; 5-15 parts of acetic acid; 2-7 parts of 27% hydrogen peroxide; 470 portions of deionized water and 550 portions; 0.5-1.5 parts of 3-mercaptopropionic acid; polyethylene glycol monomethyl ether 200-800180-300 parts; 0.5-2 parts of VC; 20-35 parts of acrylic acid; 5-10 parts of hydroxyethyl ester. Wherein the 32% sodium hydroxide solution is 32% sodium hydroxide solution, and the 27% hydrogen peroxide solution is 27% hydrogen peroxide solution.

Preferably, the starch modified comb-type coal water slurry dispersing agent is prepared from the following raw materials in parts by weight: 40 parts of starch; 18 parts of 32% sodium hydroxide solution; 10 parts of sodium sulfite; 8 parts of acetic acid; 3.7 parts of 27% hydrogen peroxide; 530 parts of deionized water; 0.9 part of 3-mercaptopropionic acid; 200 portions of methoxypolyethylene glycol 800280 portions; VC is 0.7 parts; 28 parts of acrylic acid; 6.9 parts of hydroxyethyl ester.

Preferably, the starch modified comb-type coal water slurry dispersing agent is prepared from the following raw materials in parts by weight: 80 parts of starch; 25 parts of 32% sodium hydroxide solution; 12 parts of sodium sulfite; 13 parts of acetic acid; 5.2 parts of 27% hydrogen peroxide; 510 parts of deionized water; 1.1 parts of 3-mercaptopropionic acid; 800230 parts of methoxypolyethylene glycol 200; VC is 0.6 part; 21 parts of acrylic acid; 5.8 parts of hydroxyethyl ester.

In the invention, the purity of the sodium sulfite is 60-98%.

The preparation method of the starch modified comb-type coal water slurry dispersing agent comprises the following steps:

1) starch modification: adding 30-120 parts of water and the starch with the formula amount into a reaction tank, stirring and mixing to obtain uniform starch paste, adding 32% of liquid sodium hydroxide with the formula amount, adding 1-4 parts of 27% hydrogen peroxide as an oxidant at 25-55 ℃, oxidizing at constant temperature for 1-4h, adding acetic acid with the formula amount and sodium sulfite with the formula amount to terminate the reaction, filtering, washing and drying to obtain modified starch for later use;

2) preparing a material A and a material B: the material A is obtained by uniformly mixing 160 portions of deionized water and 200 portions of 3-mercaptopropionic acid according to the formula amount and VC according to the formula amount; the material B is obtained by uniformly mixing 90-100 parts of deionized water, acrylic acid and hydroxyethyl ester according to the formula amount;

3) adding 800 parts of polyethylene glycol monomethyl ether 200-one, 200 parts of modified starch and 200 parts of deionized water 160-one into another reaction tank, stirring and mixing uniformly, adding the rest 27% hydrogen peroxide in the formula amount, stirring and mixing uniformly; after 10min, simultaneously dripping the material A and the material B into the reaction tank, wherein the dripping of the material A is finished after 2-4 hours, and the dripping of the material B is finished after 1.5-3.5 hours;

4) and continuously reacting for 2-3h after the dripping is finished, and supplementing the residual deionized water with the formula amount to obtain the product.

The starch modified comb-type coal water slurry dispersing agent has a good application effect in coal water slurry. When the starch modified comb-type coal water slurry is specifically applied, the mixed coal water slurry dispersing agent obtained by dispersing the starch modified comb-type coal water slurry or compounding the starch modified comb-type coal water slurry with other dispersing agents is added into water and coal in the form of aqueous solution; the mixing amount is 0.1-0.5% of the coal.

Preferably, the other dispersant is one or more of naphthalene sulfonic acid formaldehyde condensate, sulfamic acid formaldehyde condensate and sodium lignosulfonate.

The invention has the beneficial effects that:

1. the invention adopts the starch modified comb-type water-coal-slurry dispersing agent, so that the prepared water-coal-slurry dispersing agent contains more hydroxyl, carboxyl, carbonyl, ester group, polyoxyethylene group and other active groups, and various active groups act on water-coal-slurry particles, thereby effectively improving the dispersing effect of the water-coal-slurry.

2. The invention uses the modified starch to replace part of polyether monomers, and the proportion of the modified starch and the polyether monomers is reasonable, so that the prepared comb-type coal water slurry dispersant has good performance, and a new raw material source is found for the preparation of the comb-type coal water slurry dispersant.

3. The raw materials are reasonable in proportion, parameters in the preparation method are reasonably controlled, and the prepared starch modified comb-type coal water slurry dispersant is stable in performance.

4. The coal water slurry dispersing agent prepared by the invention has low production cost and wide raw material sources, can act on the coal water slurry alone to play a good dispersing role, and can be used for greatly improving the dispersing effect, the adaptability and the stability of products when being used after being compounded with other dispersing agents (such as naphthalene sulfonic acid formaldehyde condensate, sulfamic acid formaldehyde condensate, sodium lignosulfonate and the like) and calcined soda and the like according to a certain proportion compared with the single use.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the following examples, sodium lignosulfonate, which is denoted by NX, and a naphthalenesulfonate formaldehyde condensate, which is produced by Anhuxin solid environmental protection science and technology Co., Ltd, sodium lignosulfonate, which is denoted by SL, were used in comparative tests.

The instrument and the detection method for detecting the characteristics of the coal water slurry are as follows:

1. the experimental apparatus is a Brookield Bohler fly DV1 viscometer, 150ml beaker, halogen moisture meter, USA.

2.① switching on the power supply of the experimental instrument, adjusting the level and automatically adjusting the zero, ② taking the same amount of sample and placing the sample in a 150ml beaker to ensure the temperature and the quality of the measured sample, placing the beaker below the instrument to enable a rotor to enter the sample until the scale mark on the rotor, pressing a start key to start the test, ③ measuring the viscosity of the sample by using a 62# rotor at the speed of a shearing speed position 20, and comparing the viscosity under the same instrument, rotor, speed, container, temperature and test time.

The experimental instrument and the detection method used for the fluidity experiment are as follows:

1. laboratory apparatus

a. Truncated cone circular die: the diameter of the upper opening is 36mm, the diameter of the lower opening is 60mm, the height is 60mm, and the inner wall is smooth and seamless.

b. Glass plate (400X 400mm, thickness 5mm)

c. Straightedge in steel (300mm)

d. Scraping knife

2.① placing the glass plate in horizontal position, wetting the glass plate, truncated cone round mould, stirrer and stirring pot with wet cloth to make its surface wet without water stain ② placing the truncated cone round mould in the center of the glass plate and covering with wet cloth for standby ③ quickly injecting the water-coal-slurry into the truncated cone round mould, scraping with scraper, lifting the truncated cone round mould vertically to make the water-coal-slurry flow on the glass plate until it does not flow, measuring the maximum diameter of the flowing part in two directions perpendicular to each other with a ruler, and taking the average value as the fluidity of the water-coal-slurry.

And (3) stability testing:

the stability is detected by adopting a rod dropping method, and the required experimental instrument and the detection method are as follows:

1. laboratory apparatus

150ml beaker, electronic balance, preservative film, 300mm ruler and timer.

2. The experimental steps are as follows:

150g of the coal water slurry was weighed into a 150ml beaker, completely sealed with a sealing film, left to stand at room temperature, and the depths (H1 and H2) of 10X 200mm glass rods at 10s for 5 minutes were measured within 24 hours while the actual depths (H) were measured to calculate the soft precipitation rate and the hard precipitation rate in accordance with the following equation. Soft precipitation rate (H-H1)/Hx100%, and hard precipitation rate (H-H2)/Hx100%

The following are specific examples:

example 1:

a starch modified comb-type coal water slurry dispersing agent is prepared from the following raw materials in parts by weight: 40 parts of starch, 18 parts of 32% sodium hydroxide solution, 10 parts of sodium sulfite (90%), 8 parts of acetic acid, 3.7 parts of 27% hydrogen peroxide, 530 parts of deionized water, 0.9 part of 3-mercaptopropionic acid, 280 parts of monomer (polyethylene glycol monomethyl ether 200), 0.7 part of VC, 28 parts of acrylic acid and 6.9 parts of hydroxyethyl ester.

The method for preparing the starch modified comb-type water-coal-slurry dispersing agent comprises the following steps:

1) starch modification: adding 60 parts of deionized water and the formula amount of starch into a four-neck flask, stirring and mixing to obtain uniform starch paste, adding 32% sodium hydroxide solution in the formula amount, adding 2 parts of 27% hydrogen peroxide in the formula amount at 40 ℃, oxidizing for 3 hours at constant temperature, adding acetic acid in the formula amount and sodium sulfite in the formula amount to terminate the reaction, and filtering, washing and drying to obtain modified starch for later use.

2) Preparing a material A and a material B: the material A is obtained by uniformly mixing 180 parts of deionized water, 3-mercaptopropionic acid in a formula amount and VC in a formula amount; the material B is obtained by uniformly mixing 100 parts of deionized water, acrylic acid with the formula amount and hydroxyethyl with the formula amount.

3) Adding 180 parts of monomer, modified starch and deionized water in the formula amount into the other four-neck flask, stirring and mixing uniformly, adding the rest 27% hydrogen peroxide in the formula amount, and stirring and mixing uniformly. After 10min, the material A and the material B are dropped into the four-neck flask at the same time, wherein the material A is dropped for 2 hours, and the material B is dropped for 2.5 hours.

4) And (5) continuously reacting for 3 hours after the dripping is finished, and supplementing the residual deionized water with the formula amount to obtain the product.

The dispersant Mo-1 obtained in the example 1 is applied to coal water slurry of Qinghai salt lake, the starch modified comb-type coal water slurry dispersant Mo-1 or a mixed coal water slurry dispersant compounded with other dispersants is added into water and coal in the form of aqueous solution, the mixing amount of the dispersant is 0.1-0.5 percent of that of the coal, and various indexes such as the concentration, the viscosity, the expansion degree, the stability and the like of the coal water slurry are measured. And selecting commonly used dispersants NX (naphthalene sulfonate formaldehyde condensate) and SL (sodium lignosulfonate) on the market as a control group, and detecting various indexes such as concentration (%), viscosity (mPa.s), expansion degree (mm), stability and the like under the condition of consistent mixing amount. The results are shown in Table 1.

TABLE 1 Mo-1 comparison data of coal-water slurry concentration, viscosity, extension degree and stability at 90s coal grinding time and 0.3% dispersant addition

As can be seen from Table 1, under the condition of consistent experimental conditions and the same dispersant dosage, Mo-1 has obvious dispersibility which is slightly poorer than the dispersion effect of the commonly used NX and SL compound, but the prepared coal water slurry has poor stability. The effect of the Mo-1 compounded with SL, NX and SL + NX is better than that of Mo-1 used alone, the dispersing effect of the mixed dispersing agent Mo-1+ SL + NX obtained by the compounding ratio of the dispersing agent used in the experiment is more than that of Mo-1+ SL and more than that of Mo-1+ NX and more than that of NX + SL, and the stability of the water-coal-slurry prepared by compounding is better. However, the data table is only limited to the results obtained by the ratio of the compound mixing, and Mo-1 can be compounded and mixed with various dispersants, sodium carbonate and the like according to different ratios, so that the obtained dispersivity is different.

Example 2:

a starch modified comb-type coal water slurry dispersing agent is prepared from the following raw materials in parts by weight: 80 parts of starch, 25 parts of 32% sodium hydroxide solution, 12 parts of sodium sulfite (87%), 13 parts of acetic acid, 5.2 parts of 27% hydrogen peroxide, 540 parts of deionized water, 1.1 parts of 3-mercaptopropionic acid, 230 parts of monomer (polyethylene glycol monomethyl ether 400), 0.6 part of VC, 21 parts of acrylic acid and 5.8 parts of hydroxyethyl ester.

1) starch modification: adding 60 parts of deionized water and the formula amount of starch into a four-neck flask, stirring and mixing to obtain uniform starch paste, adding 32% sodium hydroxide solution in the formula amount, adding 3.6 parts of 27% hydrogen peroxide in the formula amount at 35 ℃, oxidizing at constant temperature for 2.5h, adding acetic acid in the formula amount and sodium sulfite in the formula amount to terminate the reaction, and filtering, washing and drying to obtain modified starch for later use.

2) Preparing a material A and a material B: the material A is obtained by uniformly mixing 170 parts of deionized water, 3-mercaptopropionic acid in a formula amount and VC in a formula amount; the material B is obtained by uniformly mixing 100 parts of deionized water, acrylic acid with the formula amount and hydroxyethyl with the formula amount.

3) Adding the monomer, the modified starch and 180 parts of deionized water in the formula amount into the other four-neck flask, stirring and mixing uniformly, adding the rest 27% hydrogen peroxide in the formula amount, and stirring and mixing uniformly. After 10min, the material A and the material B are dropped into the four-neck flask at the same time, wherein the material A is dropped for 3 hours, and the material B is dropped for 2.5 hours.

4) After the dripping is finished, the reaction is continued for 3 hours, and the residual deionized water with the formula amount is added.

The dispersant Mo-2 in the embodiment 2 is applied to coal water slurry of Qinghai salt lake, the starch modified comb-type coal water slurry dispersant Mo-2 or a mixed coal water slurry dispersant compounded with other dispersants is added into water and coal in the form of aqueous solution, the mixing amount of the dispersant is 0.1-0.5 percent of that of the coal, and various indexes such as the concentration, the viscosity, the expansion degree, the stability and the like of the coal water slurry are measured. And selecting commonly used dispersants NX (naphthalene sulfonate formaldehyde condensate) and SL (sodium lignosulfonate) on the market as a control group, and detecting various indexes such as concentration (%), viscosity (mPa.s), expansion degree (mm), stability and the like under the condition of consistent mixing amount. The results are shown in Table 2.

TABLE 2 comparison data of Mo-2 in coal milling time of 90s and 0.3% dispersant content for coal water slurry concentration, viscosity, extension degree and stability

As can be seen from Table 2, under the condition of consistent experimental conditions and the same dispersant dosage, Mo-2 has obvious dispersibility which is slightly poorer than the dispersion effect of the commonly used NX and SL compound, and the prepared coal water slurry has poor stability. The effect of the Mo-2 compounded with SL, NX and SL + NX is better than that of the Mo-2 used alone, the dispersing effect of the mixed dispersing agent Mo-2+ SL + NX obtained by the compounding ratio of the dispersing agent used in the experiment is more than that of the Mo-2+ NX and more than that of the Mo-2+ SL, and the stability of the water-coal-slurry prepared by compounding is better. However, the data table is only limited to the results obtained by the ratio of the compound mixing, and Mo-2 can be compounded and mixed with various dispersants, sodium carbonate and the like according to different ratios, so that the obtained dispersivity is different.

Example 3:

a starch modified comb-type coal water slurry dispersing agent is prepared from the following raw materials in parts by weight: 60 parts of starch, 19 parts of 32% sodium hydroxide solution, 10 parts of sodium sulfite (87%), 11 parts of acetic acid, 5.2 parts of 27% hydrogen peroxide, 510 parts of deionized water, 1.2 parts of 3-mercaptopropionic acid, 260 parts of monomer (polyethylene glycol monomethyl ether 600), 0.65 part of VC, 22 parts of acrylic acid and 6.1 parts of hydroxyethyl ester.

1) starch modification: adding 100 parts of deionized water and the starch with the formula amount into a four-neck flask, stirring and mixing to obtain uniform starch paste, adding 32% sodium hydroxide solution with the formula amount, adding 3.6 parts of 27% hydrogen peroxide with the formula amount as an oxidant at 25 ℃, oxidizing at constant temperature for 2.5h, adding acetic acid with the formula amount and sodium sulfite with the formula amount to terminate the reaction, and filtering, washing and drying to obtain the modified starch for later use.

2) Preparing a material A and a material B: the material A is obtained by uniformly mixing 110 parts of deionized water, 3-mercaptopropionic acid in a formula amount and VC in a formula amount; the material B is obtained by uniformly mixing 100 parts of deionized water, acrylic acid with the formula amount and hydroxyethyl with the formula amount.

The dispersant Mo-3 in example 3 is applied to coal water slurry of Qinghai salt lake, the coal water slurry dispersant Mo-3 obtained by the starch modified comb-type coal water slurry dispersant or a mixed coal water slurry dispersant compounded with other dispersants is added into water and coal in the form of aqueous solution, the mixing amount of the dispersant Mo-3 is 0.1-0.5 percent of that of the coal, and various indexes such as the concentration, the viscosity, the expansion degree, the stability and the like of the coal water slurry are measured. And selecting commonly used dispersants NX (naphthalene sulfonate formaldehyde condensate) and SL (sodium lignosulfonate) on the market as a control group, and detecting various indexes such as concentration (%), viscosity (mPa.s), expansion degree (mm), stability and the like under the condition of consistent mixing amount. The results are shown in Table 3.

Table 3 comparison data of concentration, viscosity, extension degree and stability of coal water slurry when the coal grinding time of Mo-3 is 90s and the mixing amount of dispersant is 0.3%

As can be seen from Table 3, under the condition of consistent experimental conditions and the same dispersant dosage, Mo-3 has obvious dispersibility which is slightly poorer than the dispersion effect of the commonly used NX and SL compound, and the prepared coal water slurry has poor stability. The effect of the Mo-3 compounded with SL, NX and SL + NX is better than that of Mo-3 used alone, the dispersing effect of the mixed dispersing agent Mo-3+ SL + NX obtained by the compounding ratio of the dispersing agent used in the experiment is more than that of Mo-3+ NX and more than that of Mo-3+ SL, and the stability of the water-coal-slurry prepared by compounding with NX, Mo-3+ NX and SL is better. However, the data table is only limited to the results obtained by the ratio of the compound mixing, and Mo-3 can be compounded and mixed with various dispersants, sodium carbonate and the like according to different ratios, and the obtained dispersivity is also different.

Example 4:

a starch modified comb-type coal water slurry dispersing agent is prepared from the following raw materials in parts by weight: 60 parts of starch, 19 parts of 32% sodium hydroxide solution, 10 parts of sodium sulfite (87%), 11 parts of acetic acid, 5.2 parts of 27% hydrogen peroxide, 510 parts of deionized water, 1.2 parts of 3-mercaptopropionic acid, 260 parts of monomer (polyethylene glycol monomethyl ether 800), 0.65 part of VC, 22 parts of acrylic acid and 6.1 parts of hydroxyethyl ester.

1) starch modification: adding 50 parts of deionized water and the formula amount of starch into a four-neck flask, stirring and mixing to obtain uniform starch paste, adding 32% sodium hydroxide solution in the formula amount, adding 3.6 parts of 27% hydrogen peroxide as an oxidant at 25 ℃, oxidizing at constant temperature for 1h, adding acetic acid in the formula amount and sodium sulfite in the formula amount to terminate the reaction, and filtering, washing and drying to obtain modified starch for later use.

2) Preparing a material A and a material B: the material A is obtained by uniformly mixing 100 parts of deionized water, 3-mercaptopropionic acid in a formula amount and VC in a formula amount; the material B is obtained by uniformly mixing 130 parts of deionized water, acrylic acid with the formula amount and hydroxyethyl with the formula amount.

3) And adding the monomer, the modified starch and 210 parts of deionized water according to the formula amount into the other four-neck flask, stirring and mixing uniformly, adding the rest 27% hydrogen peroxide according to the formula amount, and stirring and mixing uniformly. After 10min, the material A and the material B are simultaneously dropped into the four-neck flask, and the material A is dropped for 4 hours and the material B is dropped for 3 hours.

4) After the dripping is finished, the reaction is continued for 1h, and the residual deionized water with the formula amount is added.

The dispersant Mo-4 in the embodiment 4 is applied to coal water slurry of Qinghai salt lake, the coal water slurry dispersant Mo-4 obtained by the starch modified comb-type coal water slurry dispersant or a mixed coal water slurry dispersant compounded with other dispersants is added into water and coal in the form of aqueous solution, the mixing amount of the dispersant Mo-4 is 0.1-0.5 percent of that of the coal, and various indexes such as the concentration, the viscosity, the expansion degree, the stability and the like of the coal water slurry are measured. And selecting commonly used dispersants NX (naphthalene sulfonate formaldehyde condensate) and SL (sodium lignosulfonate) on the market as a control group, and detecting various indexes such as concentration (%), viscosity (mPa.s), expansion degree (mm), stability and the like under the condition of consistent mixing amount. The results are shown in Table 4.

TABLE 4 comparison data of Mo-4 in coal milling time of 90s and 0.3% dispersant content for coal water slurry concentration, viscosity, extension degree and stability

As can be seen from Table 4, under the condition of consistent experimental conditions and the same dispersant dosage, Mo-4 has obvious dispersibility, the dispersibility is poorer than the dispersion effect of the commonly used NX and SL compound, and the prepared coal water slurry has poorer stability. The effect of the compound of Mo-4 and SL, NX and SL + NX is better than that of the single use of Mo-4, the dispersion effect of the mixed dispersant NX + SL obtained by the compound proportion of the dispersant used in the experiment is more than that of Mo-4+ SL + NX is more than that of Mo-4+ NX, and the dispersion effect of Mo-4+ SL is more than that of Mo-4+ SL, and the stability of the coal water slurry prepared by the modified dispersant and the compound product thereof acting on the coal water slurry is poorer. However, the data table is only limited to the results obtained by the proportion of the compound mixing, Mo-4 can be compounded and mixed with various dispersants, sodium carbonate and the like according to different proportions, and the obtained dispersivity is also different. As can be seen from Table 4, when more deionized water is added to the material B in the step 2) and slightly more deionized water is added in the step 3), the performance of the starch modified comb-type coal water slurry dispersant is affected to a certain extent.

Example 5:

a starch modified comb-type coal water slurry dispersing agent is prepared from the following raw materials in parts by weight: 40 parts of starch, 19 parts of 32% sodium hydroxide solution, 10 parts of sodium sulfite (87%), 11 parts of acetic acid, 5.2 parts of 27% hydrogen peroxide, 500 parts of deionized water, 1.2 parts of 3-mercaptopropionic acid, 260 parts of monomer (polyethylene glycol monomethyl ether 800), 0.32 part of VC, 19 parts of acrylic acid and 5.6 parts of hydroxyethyl ester.

1) starch modification: adding 60 parts of deionized water and the formula amount of starch into a four-neck flask, stirring and mixing to obtain uniform starch paste, adding 32% sodium hydroxide solution in the formula amount, adding 3.6 parts of 27% hydrogen peroxide in the formula amount at 40 ℃, oxidizing at constant temperature for 2.5h, adding acetic acid in the formula amount and sodium sulfite in the formula amount to terminate the reaction, and filtering, washing and drying to obtain modified starch for later use.

The dispersant Mo-5 in example 5 is applied to coal water slurry in Qinghai salt lake, the coal water slurry dispersant Mo-5 obtained by the starch modified comb-type coal water slurry dispersant or a mixed coal water slurry dispersant compounded with other dispersants is added into water and coal in the form of aqueous solution, the mixing amount of the dispersant Mo-5 is 0.1-0.5 percent of that of the coal, and various indexes such as the concentration, the viscosity, the expansion degree, the stability and the like of the coal water slurry are measured. And selecting commonly used dispersants NX (naphthalene sulfonate formaldehyde condensate) and SL (sodium lignosulfonate) on the market as a control group, and detecting various indexes such as concentration (%), viscosity (mPa.s), expansion degree (mm), stability and the like under the condition of consistent mixing amount. The results are shown in Table 5.

TABLE 5 comparison data of Mo-5 in coal milling time of 90s and 0.3% dispersant content for coal water slurry concentration, viscosity, extension degree and stability

As can be seen from Table 5, under the condition of consistent experimental conditions and the same dispersant dosage, Mo-5 has obvious dispersibility which is slightly poorer than the dispersion effect of the commonly used NX and SL compound, and the prepared coal water slurry has poor stability. The effect of the Mo-5 compounded with SL, NX and SL + NX is better than that of Mo-5 used alone, the dispersing effect of the mixed dispersing agent obtained by compounding the dispersing agent in proportion in the experiment is more than that of Mo-5+ NX and more than that of NX + SL, more than that of Mo-5+ SL, and better than that of Mo-5+ NX and SL, and the stability of the water-coal-slurry prepared by compounding the Mo-5+ NX + SL is better. However, the data table is only limited to the results obtained by the ratio of the compound mixing, and Mo-5 can be compounded and mixed with various dispersants, sodium carbonate and the like according to different ratios, so that the obtained dispersivity is different. It is also clear from Table 5 that when the amount of VC is too small, the quality of the starch-modified comb-type coal-water slurry dispersant is affected to some extent.

Example 6:

a starch modified comb-type coal water slurry dispersing agent is prepared from the following raw materials in parts by weight: 160 parts of starch, 25 parts of 32% sodium hydroxide solution, 15 parts of sodium sulfite (90%), 16 parts of acetic acid, 5 parts of 27% hydrogen peroxide, 500 parts of deionized water, 0.8 part of 3-mercaptopropionic acid, 160 parts of monomer (polyethylene glycol monomethyl ether 800), 0.32 part of VC, 13 parts of acrylic acid and 2.9 parts of hydroxyethyl ester.

1) starch modification: adding 100 parts of deionized water and the formula amount of starch into a four-neck flask, stirring and mixing to obtain uniform starch paste, adding 32% sodium hydroxide solution in the formula amount, adding 4 parts of 27% hydrogen peroxide in the formula amount at 55 ℃, oxidizing for 3 hours at constant temperature, adding acetic acid in the formula amount and sodium sulfite in the formula amount to terminate the reaction, and filtering, washing and drying to obtain modified starch for later use.

2) Preparing a material A and a material B: the material A is obtained by uniformly mixing 80 parts of deionized water, 3-mercaptopropionic acid in a formula amount and VC in a formula amount; the material B is obtained by uniformly mixing 90 parts of deionized water, acrylic acid with the formula amount and hydroxyethyl with the formula amount.

3) Adding the monomer, the modified starch and 180 parts of deionized water in the formula amount into the other four-neck flask, stirring and mixing uniformly, adding the rest 27% hydrogen peroxide in the formula amount, and stirring and mixing uniformly. After 10min, the A/B material A is dropped into the four-neck flask for 2 hours, and the B material is dropped after 2 hours.

The dispersant Mo-6 in example 6 is applied to coal water slurry in Qinghai salt lake, the coal water slurry dispersant Mo-6 obtained by the starch modified comb-type coal water slurry dispersant or a mixed coal water slurry dispersant compounded with other dispersants is added into water and coal in the form of aqueous solution, the mixing amount of the dispersant Mo-6 is 0.1-0.5 percent of that of the coal, and various indexes such as the concentration, the viscosity, the expansion degree, the stability and the like of the coal water slurry are measured. And selecting commonly used dispersants NX (naphthalene sulfonate formaldehyde condensate) and SL (sodium lignosulfonate) on the market as a control group, and detecting various indexes such as concentration (%), viscosity (mPa.s), expansion degree (mm), stability and the like under the condition of consistent mixing amount. The results are shown in Table 6.

TABLE 6 comparison data of Mo-6 in coal milling time of 90s and 0.3% dispersant content for coal water slurry concentration, viscosity, extension degree and stability

As can be seen from Table 6, under the condition of consistent experimental conditions and the same dispersant dosage, Mo-6 has dispersibility which is slightly worse than the commonly used dispersion effect of the combination of NX and SL, and the prepared coal water slurry has poorer stability. The effect of the Mo-6 compounded with SL, NX and SL + NX is slightly better than that of the Mo-6 used alone, but the integral dispersing effect is poorer than that of a common dispersing agent, and the stability of the water-coal-slurry is poor. However, the data table is only limited to the results obtained by the ratio of the compound mixing, and Mo-6 can be compounded and mixed with various dispersants, sodium carbonate and the like according to different ratios, so that the obtained dispersivity is different. And as can be seen from table 6, when the amount of starch is large and the amounts of methoxypolyethylene glycol and acrylic acid are small, the quality of the obtained starch modified comb-type coal water slurry dispersant is obviously reduced, so that the addition amounts of starch, methoxypolyethylene glycol and acrylic acid need to be reasonably proportioned.

Example 7:

a starch modified comb-type coal water slurry dispersing agent is prepared from the following raw materials in parts by weight: 80 parts of starch, 20 parts of 32% sodium hydroxide solution, 13 parts of sodium sulfite (90%), 13 parts of acetic acid, 5.2 parts of 27% hydrogen peroxide, 520 parts of deionized water, 1.2 parts of 3-mercaptopropionic acid, 260 parts of monomer (polyethylene glycol monomethyl ether 1200), 0.7 part of VC, 23 parts of acrylic acid and 6.8 parts of hydroxyethyl ester.

1) starch modification: adding 50 parts of deionized water and the formula amount of starch into a four-neck flask, stirring and mixing to obtain uniform starch paste, adding 32% sodium hydroxide solution in the formula amount, adding 3.5 parts of 27% hydrogen peroxide in the formula amount at 55 ℃, oxidizing at constant temperature for 3 hours, adding acetic acid in the formula amount and sodium sulfite in the formula amount to terminate the reaction, and filtering, washing and drying to obtain modified starch for later use.

2) Preparing a material A and a material B: the material A is obtained by uniformly mixing 100 parts of deionized water, 3-mercaptopropionic acid in a formula amount and VC in a formula amount; the material B is obtained by uniformly mixing 100 parts of deionized water, acrylic acid with the formula amount and hydroxyethyl with the formula amount.

3) Adding the monomer, the modified starch and 180 parts of deionized water in the formula amount into the other four-neck flask, stirring and mixing uniformly, adding the rest 27% hydrogen peroxide in the formula amount, and stirring and mixing uniformly. After 10min, the material A and the material B are simultaneously dropped into the four-neck flask, and the material A is completely dropped for 3.5 hours, and the material B is completely dropped for 3 hours.

The dispersant Mo-7 in example 7 is applied to coal water slurry in Qinghai salt lake, the coal water slurry dispersant Mo-7 obtained by the starch modified comb-type coal water slurry dispersant or a mixed coal water slurry dispersant compounded with other dispersants is added into water and coal in the form of aqueous solution, the mixing amount of the dispersant Mo-7 is 0.1-0.5% of that of the coal, and various indexes such as the concentration, the viscosity, the expansion degree, the stability and the like of the coal water slurry are measured. And selecting commonly used dispersants NX (naphthalene sulfonate formaldehyde condensate) and SL (sodium lignosulfonate) on the market as a control group, and detecting various indexes such as concentration (%), viscosity (mPa.s), expansion degree (mm), stability and the like under the condition of consistent mixing amount. The results are shown in Table 7.

TABLE 7 comparison data of Mo-7 in coal milling time of 90s and 0.3% dispersant content for coal water slurry concentration, viscosity, extension degree and stability

As can be seen from Table 7, under the condition of consistent experimental conditions and the same dispersant dosage, Mo-7 has dispersibility which is poorer than the dispersion effect of commonly used NX and SL compounding, and the prepared coal water slurry has poorer stability. The effect of the Mo-7 compounded with SL, NX and SL + NX is slightly better than that of the Mo-7 used alone, but the integral dispersion effect is still poorer than that of a common dispersant, and the stability of the water-coal-slurry is poor. However, the data table is only limited to the results obtained by the ratio of the compound mixing, and Mo-7 can be compounded and mixed with various dispersants, sodium carbonate and the like according to different ratios, and the obtained dispersivity is also different. And as can be seen from table 7, when the molecular weight of the monomer polyethylene glycol monomethyl ether used is relatively large, the quality of the starch modified comb-type coal water slurry dispersant is remarkably reduced, so that the selection of the monomer polyethylene glycol monomethyl ether with a proper molecular weight plays an important role in the quality of the product.

Example 8:

a starch modified comb-type coal water slurry dispersing agent is prepared from the following raw materials in parts by weight: 80 parts of starch, 20 parts of 32% sodium hydroxide solution, 13 parts of sodium sulfite (90%), 13 parts of acetic acid, 5.5 parts of 27% hydrogen peroxide, 520 parts of deionized water, 1.2 parts of 3-mercaptopropionic acid, 260 parts of monomer (polyethylene glycol monomethyl ether 800), 0.85 part of VC, 43 parts of acrylic acid and 6.8 parts of hydroxyethyl ester.

4) After the dripping is finished, the reaction is continued for 1h, and the gel begins to rapidly gel after about 10min of reaction.

From example 8, it is understood that when the amount of acrylic acid is too large, the starch-modified comb-type coal-water slurry dispersant cannot be obtained.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. The starch modified comb-type coal water slurry dispersing agent is characterized by being prepared from the following raw materials in parts by weight: 20-80 parts of starch; 15-35 parts of 32% sodium hydroxide solution; 5-25 parts of sodium sulfite; 5-15 parts of acetic acid; 2-7 parts of 27% hydrogen peroxide; 470 portions of deionized water and 550 portions; 0.5-1.5 parts of 3-mercaptopropionic acid; polyethylene glycol monomethyl ether 200-800180-300 parts; 0.5-2 parts of VC; 20-35 parts of acrylic acid; 5-10 parts of hydroxyethyl ester.

2. The starch modified comb-type coal water slurry dispersant according to claim 1, which is prepared from the following raw materials in parts by weight: 40 parts of starch; 18 parts of 32% sodium hydroxide solution; 10 parts of sodium sulfite; 8 parts of acetic acid; 3.7 parts of 27% hydrogen peroxide; 530 parts of deionized water; 0.9 part of 3-mercaptopropionic acid; 200 portions of methoxypolyethylene glycol 800280 portions; VC is 0.7 parts; 28 parts of acrylic acid; 6.9 parts of hydroxyethyl ester.

3. The starch modified comb-type coal water slurry dispersant according to claim 1, which is prepared from the following raw materials in parts by weight: 80 parts of starch; 25 parts of 32% sodium hydroxide solution; 12 parts of sodium sulfite; 13 parts of acetic acid; 5.2 parts of 27% hydrogen peroxide; 510 parts of deionized water; 1.1 parts of 3-mercaptopropionic acid; 800230 parts of methoxypolyethylene glycol 200; VC is 0.6 part; 21 parts of acrylic acid; 5.8 parts of hydroxyethyl ester.

4. The starch modified comb-type coal water slurry dispersant according to any of claims 1 to 3, wherein the sodium sulfite has a purity of 60% to 98%.

5. The preparation method of the starch modified comb-type coal water slurry dispersing agent according to any one of claims 1 to 3, characterized by comprising the following steps:

6. Use of the starch modified comb-type water-coal-slurry dispersant according to any one of claims 1 to 3 in water-coal-slurry.

7. The use according to claim 6, wherein the mixed coal water slurry dispersing agent obtained by dispersing the starch modified comb-type coal water slurry or compounding the starch modified comb-type coal water slurry with other dispersing agents is added into water and coal in the form of aqueous solution; the mixing amount is 0.1-0.5% of the coal.

8. The use according to claim 7, wherein the other dispersant is one or more of a naphthalene sulfonic acid formaldehyde condensate, an aminosulfonic acid formaldehyde condensate, and sodium lignosulfonate.