Coal water slurry additive and method for preparing coal water slurry

Abstract

This invention discloses a coal-water slurry additive and a method for preparing coal-water slurry. The method for preparing the coal-water slurry additive includes the following steps: (1) styrene oxide waste liquid undergoes ring-opening polymerization under the action of an initiator, and its degree of polymerization is controlled by an electrode; (2) organic matter with a certain degree of polymerization is separated from water by a high-efficiency extractant, and high-purity polymer is obtained by distillation; (3) the obtained high-purity polymer is subjected to sulfonation and hydrolysis treatment, and its pH value is finally adjusted to obtain a coal-water slurry additive solution. Compared with traditional additives such as lignin sulfonate and naphthalene, the obtained coal-water slurry additive has better dispersion and better fluidity, can prepare high-concentration coal-water slurry, realize resource recycling, turn waste into treasure, reduce carbon emissions, and reduce environmental pollution.

Description

Technical Field

[0001] This invention relates to the fields of resource recycling and coal-water slurry preparation, and specifically to a method for preparing and applying a coal-water slurry additive. Background Technology

[0002] Coal-water slurry gasification is a clean coal technology that emerged in the 1980s. It involves preparing a coal-water slurry with coal, water, and a small amount of chemical additives, which is then fed into a gasifier to produce CO and H2 for industrial use. A high-performance coal-water slurry should possess characteristics such as high concentration, low viscosity, good fluidity, and long stability time. Under the same conditions, the lower the viscosity of the coal-water slurry, the better its fluidity, the higher the slurry concentration that can be formed, and the lower the gasification unit consumption.

[0003] Styrene oxide waste liquid is the waste liquid after purification of styrene oxide products. It contains 15-25% styrene oxide, 20-30% PGTB, and more than 50% polymers. Due to environmental protection laws and regulations, it is currently sent for incineration, resulting in extremely low utilization.

[0004] Patent CN105695001A discloses a tar-type coal-water slurry additive, proposing to use wash oil, naphthalene oil, anthracene oil, and papermaking waste liquid as the main raw materials, and to use sulfonation, condensation and other methods. However, it has limited effect on improving the slurry properties of coal slurry and cannot give full play to its advantages.

[0005] Patent CN106118764A discloses a lignosulfonate brine coal slurry additive, whose main components are naphthalene-based water-reducing agent, sodium silicate, lignosulfonate, etc., which is still a traditional lignosulfonate-naphthalene-based additive.

[0006] Although the aforementioned patents used different waste liquids and methods to prepare coal-water slurry additives, none of them effectively improved the performance of coal-water slurry. There are also schemes using styrene sulfonation reactions, but due to the large molecular weight of the polymers, most of these reactions result in unusable solid substances, hindering their effective use and utilization. Summary of the Invention

[0007] The main objective of this invention is to provide a coal-water slurry additive and a method for preparing coal-water slurry. The method utilizes sulfuric acid to pretreat styrene oxide waste liquid through ring-opening polymerization, followed by sulfonation, to obtain a highly efficient coal-water slurry additive. This improvement transforms waste into valuable resources, effectively integrating industrial park waste liquid to produce high-value-added coal-water slurry additives. It can effectively increase the concentration of coal-water slurry, reduce the operating energy consumption of the gasifier, improve the performance of the coal-water slurry, reduce environmental pollution, and lower production costs.

[0008] To achieve the above technical objectives, the present invention adopts the following technical solution.

[0009] In one aspect of the present invention, a method for preparing a coal-water slurry additive solution from styrene oxide waste liquid is provided, comprising the following steps:

[0010] 1) Add a ring-opening polymerization initiator to the styrene oxide waste liquid, and adjust the degree of polymerization of styrene oxide by adjusting the electrode strength to obtain the styrene oxide waste liquid polymer;

[0011] 2) The styrene oxide waste liquid polymer in step 1) is extracted with an extractant and purified by distillation;

[0012] 3) The polymer obtained in step 2) is subjected to sulfonation reaction with a sulfonating agent, followed by hydrolysis reaction. The pH of the hydrolyzed solution is then adjusted to 8-11 to obtain the coal-water slurry additive solution.

[0013] According to the preparation method provided by the present invention, in some examples, the concentration of the coal-water slurry additive solution is 10-50 wt% (e.g., 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%), which can be obtained by diluting with water or concentrating by heating in the reaction system.

[0014] The styrene oxide waste liquid described in this invention is generated during the process of preparing styrene oxide by styrene oxidation.

[0015] According to the preparation method provided by the present invention, preferably, the styrene oxide waste liquid contains styrene oxide: 15-25 wt%, 2,4-dicumylphenol (PGTB): 20-30 wt%, and polymers with C15 or higher: 50-60 wt%.

[0016] According to the preparation method provided by the present invention, preferably, in step 1), the initiator is one or more of sodium hydroxide, potassium hydroxide, and sulfuric acid, preferably 98wt% sulfuric acid (concentrated sulfuric acid).

[0017] According to the preparation method provided by the present invention, preferably, in step 1), the mass of concentrated sulfuric acid added is 1-5 wt% (e.g., 2 wt%, 3 wt%, 4 wt%) of the mass of the styrene oxide waste liquid.

[0018] According to the preparation method provided by the present invention, preferably, in step 1), the reaction temperature is controlled at 20-60℃ (e.g., 30℃, 40℃, 50℃), and the polymerization time is 1-4h (e.g., 2h, 2.5h, 3h); before the polymerization reaction, the power supply of the opposite and parallel electrode plates in the reactor is turned on, and the electrode voltage is stabilized at 1000-3000V (e.g., 1000V, 2500V) by adjusting the transformer, and finally the polymer is obtained.

[0019] In some examples, according to GPC testing, the average molecular weight of the polymer obtained in step 1) is between 2,000 and 30,000, preferably between 5,000 and 20,000.

[0020] According to the preparation method provided by the present invention, preferably, in step 2), the extractant is one or more of dichloromethane, tetrahydrofuran, and acetone, with dichloromethane being preferred.

[0021] According to the preparation method provided by the present invention, preferably, in step 2), the mass of the extractant added is 10-50 wt% (e.g., 20 wt%, 30 wt%, 40 wt%) of the mass of the styrene oxide waste liquid, and the extraction time is controlled to be 2-5 h (e.g., 3 h, 4 h).

[0022] According to the preparation method provided by the present invention, preferably, in step 2), the organic phase is removed, and the extractant is recovered by distillation to obtain purified styrene oxide waste liquid polymer.

[0023] According to the preparation method provided by the present invention, preferably, in step 3), the sulfonating agent comprises 98 wt% sulfuric acid and / or sulfur trioxide, preferably 98 wt% sulfuric acid.

[0024] According to the preparation method provided by the present invention, preferably, in step 3), the mass of the sulfonating agent added is 120-150 wt% (e.g., 130 wt% or 140 wt%) of the mass of the styrene oxide waste liquid.

[0025] According to the preparation method provided by the present invention, preferably, in step 3), the sulfonation reaction temperature is 120-160℃ (e.g., 130℃, 140℃, 150℃).

[0026] According to the preparation method provided by the present invention, preferably, in step 3), the sulfonation reaction time is 1-6h (e.g., 2h, 3h, 4h, 5h) to obtain the sulfonated polymer.

[0027] According to the preparation method provided by the present invention, preferably, in step 3), the water generated in the reaction is removed by distillation during the sulfonation process to promote the sulfonation reaction.

[0028] According to the preparation method provided by the present invention, preferably, in step 3), the hydrolysis reaction is carried out by adding 80-120 wt% (90 wt%, 100 wt%, 110 wt%) of water (based on the mass of styrene oxide waste liquid) to the sulfonation reaction product, controlling the hydrolysis temperature at 80-120℃ (e.g., 90℃, 100℃, 110℃), and the hydrolysis time at 0.5-2h (e.g., 1h, 1.5h) to hydrolyze and remove the unstable sulfonic acid groups.

[0029] According to the preparation method provided by the present invention, preferably, in step 3), the pH of the solution is adjusted to 8-11 by adding one or more of an alkaline solution and ammonia water, preferably a sodium hydroxide solution.

[0030] In another aspect of the present invention, an application of styrene oxide waste liquid in the preparation of coal-water slurry additive is provided, comprising the following steps: mixing the coal-water slurry additive solution prepared in the present invention with water and coal uniformly to obtain coal-water slurry.

[0031] In some examples, the dry basis mass of the coal-water slurry additive solution accounts for 0.2-1 wt% (e.g., 0.3 wt%, 0.5 wt%, 0.7 wt%, 0.9 wt%) of the dry basis mass of the coal in the coal-water slurry.

[0032] For example, the coal-water slurry additive obtained by the present invention is used according to the above application. Taking bituminous coal or sub-bituminous coal as an example, the coal-water slurry additive solution is mixed evenly with water and coal. When the coal-water slurry concentration reaches 65-70 wt%, the apparent viscosity of the coal slurry is 800 ± 100 mPa·s.

[0033] Styrene oxide undergoes polymerization under the action of a ring-opening initiator, and the degree of polymerization of the polymer is controlled by electrode strength. The product with the target degree of polymerization is then subjected to dehydration sulfonation, hydrolysis, and neutralization to form a coal-water slurry additive.

[0034] Compared with the prior art, the beneficial effects of the technical solution of the present invention are as follows:

[0035] (1) This invention utilizes the waste liquid from the styrene oxide production process for resource recycling and reuse. Through technological innovation, a high-efficiency coal-water slurry additive is developed to increase the added value of the styrene oxide waste liquid, realize resource recycling and reuse, and reduce carbon emissions.

[0036] (2) By adjusting the electrode strength, the molecular weight of styrene oxide polymers of different molecular weights can be controlled, avoiding the phenomenon of excessive polymerization and clumping in the industry, and improving the utilization rate and slurry formation effect.

[0037] (3) By adjusting the process parameters, the additives can be made to have efficient coal-water slurry preparation characteristics, improve the slurry-forming properties of raw coal, and reduce the unit consumption of gasifier operation. Detailed Implementation

[0038] To provide a detailed understanding of the technical features and content of this invention, preferred embodiments will be described in more detail below. While preferred embodiments of the invention are described in the examples, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0039] <Source of Raw Materials>

[0040] Styrene oxidation waste liquid, styrene oxidation unit of Wanhua Chemical Group Co., Ltd.;

[0041] 98% sulfuric acid, Sinopharm Chemical Reagents;

[0042] Sodium hydroxide, Sinopharm Chemical Reagent;

[0043] Dichloromethane, Sinopharm Chemical Reagent;

[0044] Powdered coal, Shenhua Group Shenyou No. 2 coal sample.

[0045] <Detection Method>

[0046] The following test methods are used in the various embodiments and comparative examples of this invention:

[0047] The concentration, viscosity, and fluidity of the coal-water slurry, as well as the testing methods, were all conducted in accordance with GB / T 18855-2008.

[0048] Viscometer: Model NXS-4C (National Coal-Water Slurry Engineering Technology Development Center).

[0049] Rapid Moisture Analyzer: Model M35M (Sartorius Scientific Instruments (Beijing) Co., Ltd.)

[0050] Molecular weight detection: Agilent 1260 Infinity II

[0051] Detection of sulfonic acid content: Wantong potentiometric titration 905, Wantong ion chromatography 930

[0052] Styrene oxide waste liquid: Styrene oxide: 21 wt%, 2,4-dicumylphenol (PGTB): 27 wt%, polymers with C15 or higher: 52 wt%.

[0053] Example 1

[0054] Styrene oxide waste liquid was placed in a reactor, and 98wt% sulfuric acid (1wt% of the waste liquid mass) was added. The reaction temperature was controlled at 20℃, and the polymerization time was 1 hour. The power supply for the parallel electrode plates in the reactor was turned on, and the electrode voltage was adjusted and stabilized at 1000V using a transformer, finally obtaining the polymer. GPC analysis showed that the molecular weight was around 2000.

[0055] Dichloromethane extractant, with a mass of 10 wt% of the styrene oxide waste liquid, was added to the reaction solution and extracted for 2 hours. After standing and separating the layers, the organic phase was removed and distilled at 80°C under normal pressure to obtain the purified styrene oxide waste liquid polymer.

[0056] The purified styrene oxide waste liquid polymer was placed in a reactor, and 98wt% concentrated sulfuric acid (120wt% of the styrene oxide waste liquid mass) was added. The reaction temperature was controlled at 120℃, and the sulfonation time was 1 hour. After the reaction, the temperature was lowered to 80℃, and water (80wt% of the styrene oxide waste liquid mass) was added for hydrolysis. The hydrolysis temperature was maintained at 80℃ for 0.5 hours. Sodium hydroxide solution was added to adjust the pH of the solution to 8. The sulfonic acid group content was analyzed to be 12.5wt%.

[0057] Preparation of coal-water slurry: Take 79.6g of coal powder and 0.2g (dry basis weight) of the coal-water slurry additive prepared above, dilute with water to 100g, stir evenly and then prepare a flowable coal-water slurry.

[0058] The fluidity was tested according to the standard method and was rated as B. The apparent viscosity of the coal-water slurry at 25°C was measured to be 867 mPa·s using a viscometer, and the concentration of the coal-water slurry was measured to be 67.7 wt% using a rapid moisture analyzer.

[0059] Example 2

[0060] Styrene oxide waste liquid was placed in a reactor, and 98wt% sulfuric acid (2wt% of the waste liquid mass) was added. The reaction temperature was controlled at 30℃, and the polymerization time was 2 hours. The power supply for the parallel electrode plates in the reactor was turned on, and the electrode voltage was stabilized at 2000V, finally yielding the polymer. GPC analysis showed that the molecular weight was around 20,000.

[0061] Dichloromethane extractant was added to the reaction solution at a mass of 50 wt% of the styrene oxide waste liquid. Extraction was carried out for 3 hours. After standing and separating the layers, the organic phase was removed and distilled at 80°C under normal pressure to obtain the purified styrene oxide waste liquid polymer.

[0062] The purified styrene oxide waste liquid polymer was placed in a reactor, and 98wt% concentrated sulfuric acid (130wt% of the styrene oxide waste liquid mass) was added. The reaction temperature was controlled at 160℃, and the sulfonation time was 3 hours. After the reaction, the temperature was lowered to 90℃, and water (100wt% of the styrene oxide waste liquid mass) was added for hydrolysis. The hydrolysis temperature was maintained at 90℃ for 1 hour. Sodium hydroxide solution was added to adjust the pH of the solution to 9. The sulfonic acid group content was analyzed to be 20.1%.

[0063] Preparation of coal-water slurry: Take 82.7g of coal powder and 0.2g (dry basis weight) of the coal-water slurry additive prepared above, dilute with water to 100g, stir evenly and then prepare a flowable coal-water slurry.

[0064] The fluidity was tested according to the standard method and was rated as A-. The apparent viscosity of the coal-water slurry at 25°C was measured to be 875 mPa·s using a viscometer, and the concentration of the coal-water slurry was measured to be 70.3 wt% using a rapid moisture analyzer.

[0065] Example 3

[0066] Styrene oxide waste liquid was placed in a reactor, and 98wt% sulfuric acid (3wt% of the waste liquid mass) was added. The reaction temperature was controlled at 40℃, and the polymerization time was 3 hours. The power supply for the parallel electrode plates in the reactor was turned on, and the electrode voltage was then controlled to stabilize at 1500V, finally yielding the polymer. GPC analysis showed that the molecular weight was around 5000.

[0067] Dichloromethane extractant was added to the reaction solution at a mass of 30 wt% of the styrene oxide waste liquid. Extraction was carried out for 4 hours. After standing and separating the layers, the organic phase was removed and distilled at 80°C under normal pressure until the topless fraction was obtained, thus obtaining the purified styrene oxide waste liquid polymer.

[0068] The purified styrene oxide waste liquid polymer was placed in a reactor, and 98wt% concentrated sulfuric acid (140wt% of the styrene oxide waste liquid mass) was added. The reaction temperature was controlled at 140℃, and the sulfonation time was 1 hour. After the reaction, the temperature was lowered to 100℃, and water (90wt% of the styrene oxide waste liquid mass) was added for hydrolysis. The hydrolysis temperature was maintained at 100℃ for 1.5 hours. The pH of the solution was adjusted to 11 by adding sodium hydroxide solution. The sulfonic acid group content was analyzed to be 15.5%.

[0069] Preparation of coal-water slurry: Take 80.8g of coal powder and 0.2g (dry basis weight) of the coal-water slurry additive prepared above, dilute with water to 100g, stir evenly and then prepare a flowable coal-water slurry.

[0070] The fluidity was tested according to standard methods and was rated as B+. The apparent viscosity of the coal-water slurry at 25°C was measured to be 885 mPa·s using a viscometer, and the concentration of the coal-water slurry was measured to be 68.7 wt% using a rapid moisture analyzer.

[0071] Example 4

[0072] Styrene oxide waste liquid was placed in a reactor, and 98wt% sulfuric acid (4wt% of the waste liquid mass) was added. The reaction temperature was controlled at 50℃, and the polymerization time was 4 hours. The power supply for the parallel electrode plates in the reactor was turned on, and the electrode voltage was then controlled and stabilized at 3000V to obtain the polymer. GPC analysis showed that the molecular weight was approximately 16000.

[0073] Dichloromethane extractant was added to the reaction solution at a mass of 40 wt% of the styrene oxide waste liquid. Extraction was carried out for 5 hours. After standing and separation, the organic phase was removed and distilled at 80°C under normal pressure to obtain the purified styrene oxide waste liquid polymer.

[0074] The purified styrene oxide waste liquid polymer was placed in a reactor, and 98wt% concentrated sulfuric acid (150wt% of the styrene oxide waste liquid mass) was added. The reaction temperature was controlled at 150℃, and the sulfonation time was 5 hours. After the reaction, the temperature was lowered to 110℃, and water (110wt% of the styrene oxide waste liquid mass) was added for hydrolysis. The hydrolysis temperature was maintained at 110℃ for 2 hours. The pH of the solution was adjusted to 10 by adding sodium hydroxide solution. The sulfonic acid group content was analyzed to be 11.6%.

[0075] Preparation of coal-water slurry: Take 79.3g of coal powder and 0.2g (dry basis weight) of the coal-water slurry additive prepared above, dilute with water to 100g, stir evenly and then prepare a flowable coal-water slurry.

[0076] The fluidity was tested according to the standard method and was rated as B. The apparent viscosity of the coal-water slurry at 25°C was measured to be 891 mPa·s using a viscometer, and the concentration of the coal-water slurry was measured to be 67.4 wt% using a rapid moisture analyzer.

[0077] Example 5

[0078] Styrene oxide waste liquid was placed in a reactor, and 98wt% sulfuric acid (5wt% of the waste liquid mass) was added. The reaction temperature was controlled at 60℃, and the polymerization time was 1 hour. The power supply for the parallel electrode plates in the reactor was turned on, and the electrode voltage was then controlled and stabilized at 2500V to obtain the polymer. GPC analysis showed that the molecular weight was around 30,000.

[0079] Dichloromethane extractant was added to the reaction solution at a mass of 20 wt% of the styrene oxide waste liquid. Extraction was carried out for 3 hours. After standing and separation, the organic phase was removed and distilled at 80°C under normal pressure to obtain the purified styrene oxide waste liquid polymer.

[0080] The purified styrene oxide waste liquid polymer was placed in a reactor, and 98wt% concentrated sulfuric acid (130wt% of the styrene oxide waste liquid mass) was added. The reaction temperature was controlled at 130℃, and the sulfonation time was 6 hours. After the reaction, the temperature was lowered to 120℃, and water (120wt% of the styrene oxide waste liquid mass) was added for hydrolysis. The hydrolysis temperature was maintained at 120℃ for 1.5 hours. The pH of the solution was adjusted to 9 by adding sodium hydroxide solution. The sulfonic acid group content was analyzed to be 16.4%.

[0081] Preparation of coal-water slurry: Take 81.1g of coal powder and 0.2g (dry basis weight) of the coal-water slurry additive prepared above, dilute with water to 100g, stir evenly and then prepare a flowable coal-water slurry.

[0082] The fluidity was tested according to standard methods and was rated as B+. The apparent viscosity of the coal-water slurry at 25°C was measured to be 878 mPa·s using a viscometer, and the concentration of the coal-water slurry was measured to be 68.9 wt% using a rapid moisture analyzer.

[0083] Comparative Example 1

[0084] Styrene oxide waste liquid was placed in a reactor, and 98wt% sulfuric acid (2wt% of the waste liquid mass) was added. The reaction temperature was controlled at 30℃, and the polymerization time was 2 hours. The electrode voltage was set to 0V, and the polymer was obtained directly. GPC analysis showed that the molecular weight was around 50,000.

[0085] Dichloromethane extractant was added to the reaction solution at a mass of 50 wt% of the styrene oxide waste liquid. Extraction was carried out for 3 hours. After standing and separating the layers, the organic phase was removed and distilled at 80°C under normal pressure to obtain the purified styrene oxide waste liquid polymer.

[0086] The purified styrene oxide waste liquid polymer was placed in a reactor, and 98wt% concentrated sulfuric acid (130wt% of the styrene oxide waste liquid mass) was added. The reaction temperature was controlled at 160℃, and the sulfonation time was 3 hours. After the reaction, the temperature was lowered to 90℃, and water (100wt% of the styrene oxide waste liquid mass) was added for hydrolysis. The hydrolysis temperature was maintained at 90℃ for 1 hour. Sodium hydroxide solution was added to adjust the pH of the solution to 9. The sulfonic acid group content was analyzed to be 4.6%.

[0087] Preparation of coal-water slurry: Take 71.1g of coal powder and 0.2g (dry basis weight) of the coal-water slurry additive prepared above, dilute with water to 100g, stir evenly and then prepare a flowable coal-water slurry.

[0088] The fluidity was tested according to standard methods and was rated as C. The apparent viscosity of the coal-water slurry at 25°C was measured to be 896 mPa·s using a viscometer, and the concentration of the coal-water slurry was measured to be 60.4 wt% using a rapid moisture analyzer.

[0089] Comparative Example 2

[0090] Styrene oxide waste liquid was placed in a reactor, and 98wt% concentrated sulfuric acid (130wt% of the waste liquid mass) was added. The reaction temperature was controlled at 160℃, and the sulfonation time was 3 hours. After the reaction, the temperature was lowered to 90℃, and water (100wt% of the waste liquid mass) was added for hydrolysis. The hydrolysis temperature was maintained at 90℃ for 1 hour. Sodium hydroxide solution was added to adjust the pH of the solution to 9. The sulfonic acid group content was analyzed to be 6.1%.

[0091] Preparation of coal-water slurry: Take 73.3g of coal powder and 0.2g (dry basis weight) of the coal-water slurry additive prepared above, dilute with water to 100g, stir evenly to obtain a flowable coal-water slurry.

[0092] The fluidity was tested according to standard methods and was rated as C+. The apparent viscosity of the coal-water slurry at 25°C was measured to be 873 mPa·s using a viscometer, and the concentration of the coal-water slurry was measured to be 62.3 wt% using a rapid moisture analyzer.

[0093] Comparative Example 3

[0094] Styrene oxide waste liquid was placed in a reactor, and sodium hydroxide was added at a mass of 4 wt% of the waste liquid. The reaction temperature was controlled at 50°C, and the polymerization time was 4 hours. Subsequently, the electrode voltage was controlled and stabilized at 3500V to obtain the final polymer. GPC analysis showed that the molecular weight was around 40,000.

[0095] Dichloromethane extractant was added to the reaction solution at a mass of 40 wt% of the styrene oxide waste liquid. Extraction was carried out for 5 hours. After standing and separation, the organic phase was removed and distilled at 80°C under normal pressure to obtain the purified styrene oxide waste liquid polymer.

[0096] The purified styrene oxide waste liquid polymer was placed in a reactor, and 98wt% concentrated sulfuric acid (100wt% of the styrene oxide waste liquid mass) was added. The reaction temperature was controlled at 150℃, and the sulfonation time was 5 hours. After the reaction, the temperature was lowered to 110℃, and water (110wt% of the styrene oxide waste liquid mass) was added for hydrolysis. The hydrolysis temperature was maintained at 110℃ for 2 hours. The pH of the solution was adjusted to 10 by adding sodium hydroxide solution. The sulfonic acid group content was analyzed to be 8.2%.

[0097] Preparation of coal-water slurry: Take 74.2g of coal powder and 0.2g (dry basis weight) of the coal-water slurry additive prepared above, dilute with water to 100g, stir evenly and then prepare a flowable coal-water slurry.

[0098] The fluidity was tested according to the standard method and was rated as B-. The apparent viscosity of the coal-water slurry at 25°C was measured to be 882 mPa·s using a viscometer, and the concentration of the coal-water slurry was measured to be 63.1 wt% using a rapid moisture analyzer.

[0099] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for preparing a coal-water slurry additive solution, comprising the following steps: 1) Add a ring-opening polymerization initiator to the styrene oxide waste liquid, and adjust the degree of polymerization of styrene oxide by adjusting the electrode strength to obtain the styrene oxide waste liquid polymer; 2) The styrene oxide waste liquid polymer in step 1) is extracted with an extractant and purified by distillation; 3) The polymer obtained in step 2) is subjected to sulfonation reaction with a sulfonating agent, followed by hydrolysis reaction. The pH of the hydrolyzed solution is then adjusted to 8-11 to obtain the coal-water slurry additive solution.

2. The method according to claim 1, characterized in that, The styrene oxide waste liquid contains the following components: 15-25 wt% styrene oxide 2,4-Dicumylphenol 20-30 wt%, 50-60 wt% of polymers with C15 or higher.

3. The method according to claim 1, characterized in that, In step 1), the initiator is one or more of sodium hydroxide, potassium hydroxide, and sulfuric acid.

4. The method according to claim 1, characterized in that, In step 1), the initiator is 98 wt% sulfuric acid.

5. The method according to claim 1, characterized in that, In step 1), the reaction temperature is controlled at 20-60℃ and the polymerization time is 1-4h.

6. The method according to claim 1, characterized in that, Before the polymerization reaction, turn on the power supply for the opposite and parallel electrode plates in the reactor, and stabilize the electrode voltage to 1000-3000V by adjusting the transformer.

7. The method according to claim 1, characterized in that, The average molecular weight of the polymer obtained in step 1) is between 2000 and 30000.

8. The method according to claim 1, characterized in that, The average molecular weight of the polymer obtained in step 1) is between 5,000 and 20,000.

9. The method according to claim 1, characterized in that, In step 3), the sulfonating agent contains 98 wt% sulfuric acid and / or sulfur trioxide.

10. The method according to claim 1, characterized in that, In step 3), the sulfonation reaction temperature is 120-160℃ and the sulfonation reaction time is 1-6h.

11. A method for preparing coal-water slurry, comprising the following steps: The water-coal slurry additive solution prepared by the method according to any one of claims 1-10 is mixed evenly with water and coal to obtain water-coal slurry.

12. The method according to claim 11, characterized in that, The dry basis mass of the coal-water slurry additive solution accounts for 0.2-1 wt% of the dry basis mass of the coal in the coal-water slurry.