Environment-friendly composite coal water slurry additive and preparation method thereof

Abstract

The invention discloses an environment-friendly composite coal water slurry additive and a preparation method thereof. The preparation method comprises the following steps: adding fatty alcohol-polyoxyethylene ether into water, stirring at the temperature of 40-50 DEG C, adding sodium gluconate, maintaining the pH value of a system to be 7-8, and stirring to obtain a prefabricated material; the method comprises the following steps: adjusting the pH value of papermaking waste liquid to 5-7, adding an initiator and FeSO4. 7H2O, uniformly mixing, carrying out microwave treatment, adding amino-terminated polyamidoamine, stirring under the protection of nitrogen, and desalting by adopting a bipolar membrane electrodialysis system to obtain pretreated waste liquid; and slowly adding the pretreatment waste liquid into the prefabricated material, fully stirring, and adjusting the solid content of the system with water to obtain the environment-friendly composite coal water slurry additive. The raw materials are simple and easy to obtain, the process is simple, the coal slurry has the characteristics of high concentration, fluidity and stability, the additive can replace the existing naphthalene-based coal water slurry additive, the cost is reduced, and the additive is suitable for large-scale popularization and application.

Description

Technical Field

[0001] The invention relates to the technical field of coal water slurry additives, and in particular to an environmentally friendly composite coal water slurry additive and a preparation method thereof. Background Art

[0002] Coal-water slurry is a coal-based fluid fuel and gasification raw material made from 60-65% coal, 40-35% water and about 0.1-0.2% additives through a certain processing technology. Its main utilization methods are combustion release and gasification synthesis of coal chemical raw materials.

[0003] Coal quality, coal powder particle size distribution, and additives are the three major factors that affect the preparation of water-coal slurry, among which coal quality determines the slurry effect of coal. Particle size distribution is the composition of particle sizes in water-coal slurry products, and is one of the key factors affecting slurrying. Grinding raw coal into water-coal slurry products requires that the particle size composition of the product has a high stacking efficiency, the stacking gap is minimal, the gaps between large particles are filled with smaller particles, and the gaps between small particles are filled with even smaller particles, thereby reducing the amount of water in the gaps, increasing the slurrying concentration, and improving the fluidity of coal slurry.

[0004] Additives are mainly used to improve the stability of coal slurry to facilitate long-distance transportation and storage. Since water-coal slurry is a coarse dispersion system of solid and liquid phases, coal particles can easily agglomerate with each other spontaneously, and precipitation can easily occur under the action of gravity or other external forces. In order to prevent precipitation or the formation of irreversible hard precipitation, additives are added to the water-coal slurry to make the coarse particle suspension of the water-coal slurry form a thixotropic body. That is, the water-coal slurry becomes structured when it is left to stand, and has high shear stress. When used, once an external force is applied, the viscosity can be rapidly reduced, and it has good fluidity, and it can restore its original structural state when left to stand.

[0005] Among the properties of high-concentration water-coal slurry, the most important are low viscosity, good stability and fluidity. However, coal is a hydrophobic substance and a particle suspension. Even if the coal is easy to slurry and has a high-pile particle distribution, it is impossible to make the desired high-concentration water-coal slurry without chemical additives. The main function of the additive is to change the surface properties of the coal particles, promote the dispersion of the particles in water, and make the slurry have good rheological properties and stability.

[0006] There are many additive manufacturers on the market, but the quality of their products varies. Although traditional naphthalene sulfonate additives can improve slurry performance, they have significant defects: first, the introduction of excessive sulfate leads to scaling of the slag water system; second, the accompanying chlorine and phosphorus ions increase the difficulty of sewage treatment and environmental protection costs; third, the synthesis process of naphthalene raw materials is complex and expensive. In addition, the existing additives have limited adaptability to coal types, and it is difficult to take into account the low viscosity and long-term stability of high-concentration slurries. Therefore, the development of environmentally friendly, low-cost and widely applicable alternative additives has become an urgent need in the industry. Summary of the invention

[0007] The purpose of the present invention is to solve the shortcomings of the prior art and to propose an environmentally friendly composite water-coal slurry additive and a preparation method thereof.

[0008] A method for preparing an environmentally friendly composite coal water slurry additive comprises the following steps:

[0009] S1. Add fatty alcohol polyoxyethylene ether to water, stir at a temperature of 40-50° C., add sodium gluconate, maintain the pH value of the system at 7-8, stir, and obtain a prefabricated material;

[0010] S2, adjust the pH value of papermaking waste liquid to 5-7, add initiator, FeSO 4 7H 2 O are mixed evenly, subjected to microwave treatment, the microwave temperature is 60-80°C, the microwave power is 400-500W, amino-terminated polyamidoamine is added, and under nitrogen protection, the temperature is stirred at 40-50°C, the temperature is increased to 70-80°C and the stirring is continued, and a bipolar membrane electrodialysis system is used for desalination to obtain a pretreated waste liquid with a conductivity of ≤500μS / cm;

[0011] S3. Slowly add the pretreated waste liquid to the prefabricated material, control the temperature to ≤50°C, stir fully, and use water to adjust the solid content of the system to 30-42% to obtain an environmentally friendly composite water-coal slurry additive.

[0012] Preferably, in S1, the weight ratio of fatty alcohol polyoxyethylene ether to sodium gluconate is 1-5:1.5-2.

[0013] Fatty alcohol polyoxyethylene ether is the most important type of nonionic surfactant. The ether bond in the molecule is not easily destroyed by acid or alkali, so it has high stability, good water solubility, good electrolyte resistance, easy biodegradation, and small foam.

[0014] Fatty alcohol polyoxyethylene ether, general formula RO(CH 2 CH 2 O) n H, where R is C 12 -C 18 A straight-chain or branched fatty alcohol group, n is the addition number of ethylene oxide (EO); preferably, the fatty alcohol polyoxyethylene ether is AEO-7 fatty alcohol polyoxyethylene ether.

[0015] Preferably, in S2, papermaking waste liquid, amino-terminated polyamidoamine, initiator, FeSO 4 7H 2 The weight ratio of O is 7-15:1-3:0.1-0.2:0.01-0.05.

[0016] Preferably, in S2, the papermaking waste liquor is sulfite chemical pulping waste liquor, wherein the concentration of sodium lignin sulfonate is 10-30 g / L, and the concentration of hemicellulose decomposition products is 20-40 g / L.

[0017] Preferably, in S2, the initiator is ammonium persulfate.

[0018] Preferably, in S2, the amino-terminated polyamidoamine has a generation number of 3.0.

[0019] Preferably, in S2, a bipolar membrane electrodialysis system is used for desalination, wherein the operating voltage is 3-5V and the current density is 10-15mA / cm 2 .

[0020] An environmentally friendly composite water-coal slurry additive is prepared by adopting the preparation method of the environmentally friendly composite water-coal slurry additive.

[0021] Beneficial effects:

[0022] In the present invention, an initiator is added to the papermaking waste liquid, and microwave-assisted initiation is used to cross-link lignin sulfonate with terminal amino polyamide amine to form a three-dimensional network structure. The terminal amino group is combined with oxygen-containing functional groups (such as carboxyl and hydroxyl) on the surface of coal through electrostatic adsorption. At the same time, hyperbranched molecules are embedded in the cracks of coal particles, and lignin sulfonate wraps the particle surface to form a double stable layer. Even with high-concentration coal slurry, the low viscosity and long-term stability of the slurry can be guaranteed.

[0023] Fatty alcohol polyoxyethylene ether is a type of nonionic surfactant, the ether bonds in its molecules are not easily destroyed by acids and alkalis, and have high stability. The present invention adopts sodium gluconate and fatty alcohol polyoxyethylene ether to compound, which not only reduces the entry of sulfate, chloride and phosphorus ions, but also effectively increases the adaptability of coal through the ratio of fatty alcohol polyoxyethylene ether and sodium gluconate in process control, and the slurrying performance of coal is good.

[0024] Sodium gluconate can chelate Ca in coal 2+ Mg 2+ Plasma reduces hard precipitation; through hydrogen bonds and lignin sulfonate, it forms a three-dimensional network structure, giving the slurry thixotropy, and cooperates with the pre-treatment waste liquid to ensure high coal slurry concentration and significantly enhance the stability and fluidity of the system.

[0025] The invention reduces the entry of sulfate radicals, chloride ions and phosphorus ions, and at the same time fully utilizes papermaking waste liquid in the papermaking industry. The additive has adaptability to multiple types of coal, a wide range of use, and can be widely used in the fields of raw material water-coal slurry and fuel water-coal slurry, and can be used to replace the water reducer commonly used in construction.

[0026] The raw materials of the invention are simple and easy to obtain, the process is simple, the operation is easy, and the requirements for production equipment are not high. The obtained water-coal slurry additive can significantly improve the performance of the coal slurry, and has high coal slurry concentration, excellent fluidity and stability. It can replace the existing naphthalene-based water-coal slurry additive, reduce costs, and is suitable for large-scale promotion and use. DETAILED DESCRIPTION

[0027] The present invention will be further explained below in conjunction with specific embodiments.

[0028] The following examples and comparative examples use Hengli Petrochemical Shenyou 2# coal as raw material, and according to the particle size requirements of the water-coal slurry for gasification, the coal powder of the required particle size is prepared. The particle size distribution is closer to actual production. The particle size distribution of the experimental coal powder is shown in the following table:

[0029] Mesh range >14 14～40 40～200 200～325 <325 Proportion(%) 0.00 10.00 45.00 15.00 30.00

[0030] Example 1

[0031] A method for preparing an environmentally friendly composite coal water slurry additive comprises the following steps:

[0032] S1. Add 1 part of fatty alcohol polyoxyethylene ether to 15 parts of water by weight, stir at 40°C for 20 min at a stirring speed of 200 r / min, add 1.5 parts of sodium gluconate, maintain the pH value of the system at 7, stir for 10 min at a stirring speed of 1000 r / min, and obtain a prefabricated material;

[0033] S2, adjust the pH value of 7 parts of papermaking waste liquid to 5, add 0.1 parts of ammonium persulfate, 0.01 parts of FeSO 4 7H 2 O was mixed evenly, microwaved for 10 min, the microwave temperature was 60 ° C, the microwave power was 400 W, 1 part of 3.0 generation amino-terminated polyamidoamine was added, and under nitrogen protection, the temperature was stirred at 40 ° C for 10 min, the temperature was raised to 70 ° C and stirred for 1 h, and a bipolar membrane electrodialysis system was used for desalination, wherein the operating voltage was 3 V and the current density was 10 mA / cm 2 , obtaining a pretreated waste liquid with a conductivity of ≤500 μS / cm;

[0034] The papermaking waste liquid is sulfite process chemical pulping waste liquid, wherein the concentration of sodium lignin sulfonate is 10 g / L, and the concentration of hemicellulose decomposition products is 20 g / L;

[0035] S3. Slowly add the pretreated waste liquid to the prefabricated material, control the temperature ≤50°C, fully stir for 30 minutes, the stirring speed is 800r / min, and use water to adjust the solid content of the system to 42% to obtain an environmentally friendly composite water-coal slurry additive.

[0036] In order to test the performance of the coal water slurry additive, Hengli Petrochemical Shenyou 2# coal was used as raw material, and pulping was performed after drying at a temperature of 120°C. The highest pulping concentration could reach 62.47%, and no hard precipitation was produced in 15 days. The amount of additive (converted to solid) was 2.35% of the mass of coal (dry basis). The coal water slurry additive of this embodiment not only has good dispersibility, but also has good stability.

[0037] Example 2

[0038] A method for preparing an environmentally friendly composite coal water slurry additive comprises the following steps:

[0039] S1. Add 5 parts of fatty alcohol polyoxyethylene ether by weight to 30 parts of water, stir at 50°C for 30 min at a stirring speed of 400 r / min, add 2 parts of sodium gluconate, maintain the pH value of the system at 8, stir for 30 min at a stirring speed of 1500 r / min, and obtain a prefabricated material;

[0040] S2, adjust the pH value of 15 parts of papermaking waste liquid to 6.9, add 0.2 parts of ammonium persulfate, 0.05 parts of FeSO 4 7H 2 O was mixed evenly, and microwave treatment was performed for 20 min at a microwave temperature of 80 ° C and a microwave power of 500 W. Three portions of 3.0 generation amino-terminated polyamidoamine were added. Under nitrogen protection, the mixture was stirred at 50 ° C for 20 min, and the temperature was raised to 80 ° C and stirred for 2 h. A bipolar membrane electrodialysis system was used for desalination, wherein the operating voltage was 5 V and the current density was 15 mA / cm 2 , obtaining a pretreated waste liquid with a conductivity of ≤500 μS / cm;

[0041] The papermaking waste liquid is sulfite process chemical pulping waste liquid, wherein the concentration of sodium lignin sulfonate is 30 g / L and the concentration of hemicellulose decomposition products is 40 g / L;

[0042] S3. Slowly add the pretreated waste liquid to the prefabricated material, control the temperature ≤50°C, fully stir for 40 minutes, the stirring speed is 1200r / min, and use water to adjust the solid content of the system to 42% to obtain an environmentally friendly composite water-coal slurry additive.

[0043] In order to test the performance of the coal water slurry additive, Hengli Petrochemical Shenyou 2# coal was used as raw material, and pulped after drying at a temperature of 120°C. The highest pulping concentration could reach 62.51%, and no hard precipitation was produced in 15 days. The amount of additive (converted to solid) was 2.35% of the mass of coal (dry basis). The coal water slurry additive of this embodiment not only has good dispersibility, but also has good stability.

[0044] Example 3

[0045] A method for preparing an environmentally friendly composite coal water slurry additive comprises the following steps:

[0046] S1. Add 2 parts of fatty alcohol polyoxyethylene ether by weight to 18 parts of water, stir at 42°C for 22 min at a stirring speed of 250 r / min, add 1.6 parts of sodium gluconate, maintain the pH value of the system at 7.2, stir for 12 min at a stirring speed of 1200 r / min, and obtain a prefabricated material;

[0047] S2, adjust the pH value of 8 parts of papermaking waste liquid to 5.5, add 0.12 parts of ammonium persulfate, 0.02 parts of FeSO 4 7H 2 O was mixed evenly, and microwave treatment was performed for 12 min at a microwave temperature of 65 ° C and a microwave power of 420 W. 1.5 parts of 3.0 generation amino-terminated polyamidoamine were added. Under nitrogen protection, the mixture was stirred at 41 ° C for 12 min, and the temperature was raised to 72 ° C and stirred for 1.2 h. A bipolar membrane electrodialysis system was used for desalination, wherein the operating voltage was 3.5 V and the current density was 12 mA / cm 2 , obtaining a pretreated waste liquid with a conductivity of ≤500 μS / cm;

[0048] The papermaking waste liquid is sulfite process chemical pulping waste liquid, wherein the concentration of sodium lignin sulfonate is 15 g / L and the concentration of hemicellulose decomposition products is 25 g / L;

[0049] S3. Slowly add the pretreated waste liquid to the prefabricated material, control the temperature ≤50°C, fully stir for 32 minutes, the stirring speed is 900r / min, and use water to adjust the solid content of the system to 42% to obtain an environmentally friendly composite water-coal slurry additive.

[0050] In order to test the performance of the coal water slurry additive, Hengli Petrochemical Shenyou 2# coal was used as raw material, and pulping was performed after drying at a temperature of 120°C. The highest pulping concentration could reach 62.53%, and no hard precipitation was produced in 15 days. The amount of additive (converted to solid) was 2.35% of the mass of coal (dry basis). The coal water slurry additive of this embodiment not only has good dispersibility, but also has good stability.

[0051] Example 4

[0052] A method for preparing an environmentally friendly composite coal water slurry additive comprises the following steps:

[0053] S1. Add 3 parts of fatty alcohol polyoxyethylene ether by weight to 28 parts of water, stir at 48°C for 25 min at a stirring speed of 300 r / min, add 1.8 parts of sodium gluconate, maintain the pH value of the system at 7.5, stir for 25 min at a stirring speed of 1400 r / min, and obtain a prefabricated material;

[0054] S2, adjust the pH value of 12 parts of papermaking waste liquid to 6.8, add 0.18 parts of ammonium persulfate, 0.04 parts of FeSO 4 7H 2 O was mixed evenly, and microwave treatment was performed for 15 min at a microwave temperature of 78 ° C and a microwave power of 480 W. 2.5 parts of 3.0 generation amino-terminated polyamidoamine were added. Under nitrogen protection, the mixture was stirred at 48 ° C for 18 min, and the temperature was raised to 78 ° C and stirred for 1.5 h. A bipolar membrane electrodialysis system was used for desalination, wherein the operating voltage was 4.5 V and the current density was 14 mA / cm 2 , obtaining a pretreated waste liquid with a conductivity of ≤500 μS / cm;

[0055] The papermaking waste liquid is sulfite process chemical pulping waste liquid, wherein the concentration of sodium lignin sulfonate is 26 g / L, and the concentration of hemicellulose decomposition products is 38 g / L;

[0056] S3. Slowly add the pretreated waste liquid to the prefabricated material, control the temperature ≤50°C, fully stir for 38 minutes, the stirring speed is 1100r / min, and use water to adjust the solid content of the system to 42% to obtain an environmentally friendly composite water-coal slurry additive.

[0057] In order to test the performance of the water-coal slurry additive, Hengli Petrochemical Shenyou 2# coal was used as raw material, and pulping was performed after drying at a temperature of 120°C. The highest pulping concentration could reach 62.52%, and no hard precipitation was produced in 15 days. The amount of additive (converted to solid) was 2.35% of the mass of coal (dry basis). The water-coal slurry additive of this embodiment not only has good dispersibility, but also has good stability.

[0058] Example 5

[0059] A method for preparing an environmentally friendly composite coal water slurry additive comprises the following steps:

[0060] S1. Add 2 parts of fatty alcohol polyoxyethylene ether by weight to 25 parts of water, stir at 45°C for 25 min at a stirring speed of 300 r / min, add 1.8 parts of sodium gluconate, maintain the pH value of the system at 7.6, stir for 18 min at a stirring speed of 1200 r / min, and obtain a prefabricated material;

[0061] S2, adjust the pH value of 10 parts of papermaking waste liquid to 6, add 0.15 parts of ammonium persulfate, 0.03 parts of FeSO 4 7H 2 O was mixed evenly, microwaved for 15 min, the microwave temperature was 70 ° C, the microwave power was 450 W, 2 parts of 3.0 generation amino-terminated polyamidoamine were added, and under nitrogen protection, the temperature was stirred at 45 ° C for 15 min, the temperature was raised to 75 ° C and stirred for 1.5 h, and a bipolar membrane electrodialysis system was used for desalination, wherein the operating voltage was 4 V and the current density was 15 mA / cm2 , obtaining a pretreated waste liquid with a conductivity of ≤500 μS / cm;

[0062] The papermaking waste liquid is sulfite process chemical pulping waste liquid, wherein the concentration of sodium lignin sulfonate is 20 g / L, and the concentration of hemicellulose decomposition products is 30 g / L;

[0063] S3. Slowly add the pretreated waste liquid to the prefabricated material, control the temperature ≤50°C, fully stir for 35 minutes, the stirring speed is 1000r / min, and use water to adjust the solid content of the system to 42% to obtain an environmentally friendly composite water-coal slurry additive.

[0064] In order to test the performance of the coal water slurry additive, Hengli Petrochemical Shenyou 2# coal was used as raw material, and pulped after drying at a temperature of 120°C. The highest pulping concentration could reach 62.51%, and no hard precipitation was produced in 15 days. The amount of additive (converted to solid) was 2.35% of the mass of coal (dry basis). The coal water slurry additive of this embodiment not only has good dispersibility, but also has good stability.

[0065] Comparative Example 1

[0066] Naphthalene additives produced by Laiwu Shuangquan Building Materials Co., Ltd. were used, and Hengli Petrochemical Shenyou 2# coal was used as raw material. The pulp was made after drying at a temperature of 120°C. The highest pulping concentration was 62.43%, and hard precipitate was produced in 13 days. The amount of additives used (converted to solid) was 2.35% of the mass of the coal (dry basis).

[0067] Comparative Example 2

[0068] A method for preparing an environmentally friendly composite coal water slurry additive comprises the following steps:

[0069] S1. Add 2 parts of fatty alcohol polyoxyethylene ether by weight to 25 parts of water, stir at 45°C for 25 min at a stirring speed of 300 r / min, add 1.8 parts of sodium gluconate, maintain the pH value of the system at 7.6, stir for 18 min at a stirring speed of 1200 r / min, and obtain a prefabricated material;

[0070] S2. Adjust the pH value of 10 parts of papermaking wastewater to 6, then add 2 parts of 3.0 generation amino-terminated polyamide amine and mix evenly, and use bipolar membrane electrodialysis system for desalination, where the operating voltage is 4V and the current density is 15mA / cm 2 , obtaining a pretreated waste liquid with a conductivity of ≤500 μS / cm;

[0071] The papermaking waste liquid is sulfite process chemical pulping waste liquid, wherein the concentration of sodium lignin sulfonate is 20 g / L, and the concentration of hemicellulose decomposition products is 30 g / L;

[0072] S3. Slowly add the pretreated waste liquid to the prefabricated material, control the temperature ≤50°C, fully stir for 35 minutes, the stirring speed is 1000r / min, and use water to adjust the solid content of the system to 42% to obtain an environmentally friendly composite water-coal slurry additive.

[0073] Hengli Petrochemical Shenyou 2# coal was used as raw material, and pulping was performed after drying at 120°C. The highest pulping concentration was 60.65%, and hard precipitate was generated in 10 days. The amount of additives (solid basis) was 2.35% of the coal (dry basis) mass.

[0074] Comparative Example 3

[0075] A method for preparing an environmentally friendly composite coal water slurry additive comprises the following steps:

[0076] S1. Add 2 parts of fatty alcohol polyoxyethylene ether by weight to 25 parts of water, stir at 45°C for 25 min at a stirring speed of 300 r / min, add 1.8 parts of sodium gluconate, maintain the pH value of the system at 7.6, stir for 18 min at a stirring speed of 1200 r / min, and obtain a prefabricated material;

[0077] S2, adjust the pH value of 10 parts of papermaking waste liquid to 6, add 0.15 parts of ammonium persulfate, 0.03 parts of FeSO 4 7H 2 O was mixed evenly, and microwave treatment was performed for 15 min, the microwave temperature was 70 °C, the microwave power was 450 W, and the bipolar membrane electrodialysis system was used for desalination, wherein the operating voltage was 4 V and the current density was 15 mA / cm 2 , obtaining a pretreated waste liquid with a conductivity of ≤500 μS / cm;

[0078] The papermaking waste liquid is sulfite process chemical pulping waste liquid, wherein the concentration of sodium lignin sulfonate is 20 g / L, and the concentration of hemicellulose decomposition products is 30 g / L;

[0079] S3. Slowly add the pretreated waste liquid to the prefabricated material, control the temperature ≤50°C, fully stir for 35 minutes, and stir at a speed of 1000r / min. Add 2 parts of 3.0-generation amino-terminated polyamidoamine, and use water to adjust the solid content of the system to 42% to obtain an environmentally friendly composite water-coal slurry additive.

[0080] Hengli Petrochemical Shenyou 2# coal was used as raw material, and pulping was performed after drying at 120°C. The highest pulping concentration was 59.32%, and hard precipitate was generated in 10 days. The amount of additives (solid basis) was 2.35% of the coal (dry basis) mass.

[0081] The water-coal slurry additives of Example 5 and Comparative Examples 1-3 were tested with the additive dosage (solid basis) being 2.35% of the mass of coal (dry basis).

[0082] The concentration of coal slurry was determined by referring to GB / T 18856.2-2008 "Test method for coal-water slurry Part 2: Determination of concentration"; the viscosity of coal slurry was determined by referring to GB / T 18856.2-2008 "Test method for coal-water slurry Part 4: Determination of apparent viscosity".

[0083] The fluidity of coal slurry is determined by visual inspection, and the coal slurry is divided into three grades: A (continuous flow), B (intermittent flow), and C (almost no flow or no flow); Grade A is a thin fluid, which flows continuously, smoothly and uninterruptedly; Grade B is a thick fluid, which flows relatively continuously but has a rough surface; Grade C is a fluid that can only flow well with the help of external force or is muddy and cannot flow; "+" indicates better fluidity in a certain grade; "-" indicates poorer fluidity in a certain grade.

[0084] The water separation rate was determined with reference to GB / T18856.5-2008 "Test methods for coal-water slurry Part 5: Determination of stability", as follows: Pour the sample into a 100mL measuring cylinder, let it stand for 24 hours, read the scale value, and determine the water separation rate.

[0085] Refer to GB / T 8077-2012 "Test method for homogeneity of concrete admixtures" to determine the content of sodium sulfate and chloride ions.

[0086] The performance test results are shown in Table 1.

[0087] Table 1 Performance test results of coal water slurry additives obtained in Example 5 and Comparative Examples 1-3

[0088]

[0089] It can be seen from the above table that the environmentally friendly water-coal slurry additive obtained in Example 5 of the present invention has achieved similar effects as the common naphthalene additives on the market through laboratory simulation tests, but has reduced environmental pressure and is suitable for large-scale promotion and use.

[0090] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for preparing an environmentally friendly composite coal water slurry additive, characterized in that: The steps include: S1. Add fatty alcohol polyoxyethylene ether to water, stir at a temperature of 40-50° C., add sodium gluconate, maintain the pH value of the system at 7-8, stir, and obtain a prefabricated material; S2, adjusting the pH value of the papermaking waste liquid to 5-7, adding an initiator and FeSO4·7H2O and mixing evenly, subjecting to microwave treatment, with a microwave temperature of 60-80°C and a microwave power of 400-500W, adding amino-terminated polyamidoamine, stirring at a temperature of 40-50°C under nitrogen protection, raising the temperature to 70-80°C and continuing stirring, and using a bipolar membrane electrodialysis system for desalination to obtain a pretreated waste liquid with a conductivity of ≤500μS / cm; S3. Slowly add the pretreated waste liquid to the prefabricated material, control the temperature to ≤50°C, stir fully, and use water to adjust the solid content of the system to 30-42% to obtain an environmentally friendly composite water-coal slurry additive.

2. The method for preparing the environmentally friendly composite coal water slurry additive according to claim 1, characterized in that: In S1, the weight ratio of fatty alcohol polyoxyethylene ether to sodium gluconate is 1-5:1.5-2.

3. The method for preparing the environmentally friendly composite coal water slurry additive according to claim 1, characterized in that: In S2, the weight ratio of papermaking waste liquid, amino-terminated polyamidoamine, initiator and FeSO4·7H2O is 7-15:1-3:0.1-0.2:0.01-0.

05.

4. The method for preparing the environmentally friendly composite coal water slurry additive according to claim 1, characterized in that: In S2, the papermaking waste liquid is sulfite process chemical pulping waste liquid, wherein the concentration of sodium lignin sulfonate is 10-30 g / L, and the concentration of hemicellulose decomposition products is 20-40 g / L.

5. The method for preparing the environmentally friendly composite coal water slurry additive according to claim 1, characterized in that: In S2, the initiator is ammonium persulfate.

6. The method for preparing the environmentally friendly composite coal water slurry additive according to claim 1, characterized in that: In S2, the amino-terminated polyamidoamine has a generation number of 3.

0.

7. The method for preparing the environmentally friendly composite coal water slurry additive according to claim 1, characterized in that: In S2, a bipolar membrane electrodialysis system is used for desalination, with an operating voltage of 3-5 V and a current density of 10-15 mA / cm 2 .

8. An environmentally friendly composite coal water slurry additive, characterized in that: The environmentally friendly composite water-coal slurry additive is prepared by the preparation method of any one of claims 1 to 7.

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