High-temperature-resistant flocculant as well as preparation method and application thereof

Abstract

The invention discloses a high-temperature-resistant flocculant as well as a preparation method and application thereof.According to the high-temperature-resistant flocculant, coal gasification slag is adopted for preparing the flocculant, so that the agent cost in the wastewater treatment stage of a coal gasification process is reduced; by introducing the intelligent polymer, the structure and performance of the flocculant can be automatically adjusted according to the reaction temperature, the reaction pH and the ion concentration so as to adapt to complex and changeable wastewater treatment requirements, so that the dependence on reaction conditions is reduced, and the complexity of wastewater treatment procedures and the environmental condition control cost are further reduced; the flocculating agent is subjected to surface activity treatment, so that the heavy metal ion capturing capacity of the flocculating agent is improved, and the wastewater treatment effect is improved.

Description

Technical Field

[0001] The invention relates to the technical field of coal gasification, in particular to a high temperature resistant flocculant and a preparation method thereof, and application thereof in a coal gasification process. Background Art

[0002] The coal gasification process is a chemical technology that converts coal into combustible gas. The commonly used coal gasification technology is the water-coal slurry pressurized gasification technology. Since this technology consumes a large amount of water, in order to save water, a wastewater recycling process is generally added to the coal gasification process. That is, the dehydrated filtrate after flash evaporation of the gasifier discharge water and the washing tower discharge water is reused as the make-up water for the preparation of water-coal slurry, and part of the ash water is used as the washing tower supplementary circulating water after heat exchange, and part of it is cooled and discharged as sewage to the biochemical sewage treatment system, and discharged or reused after treatment meets the standards.

[0003] In the process of coal gasification wastewater recovery, flocculants are needed to make impurities such as suspended matter and colloidal particles in the wastewater condense and flocculate to form larger particles, thereby accelerating their sedimentation, so as to achieve the purpose of reducing suspended matter and turbidity in the water body. However, the existing coal gasification process has the following defects in the flocculant wastewater treatment process: First, the coal gasification wastewater treatment process needs to consume a large amount of flocculants, resulting in a high cost of the wastewater treatment process; second, in order to achieve the best capture ability of the flocculant, the environmental conditions of the reaction need to be strictly controlled, which will increase the complexity of the wastewater treatment process and further increase the cost; third, the flocculants used in the existing wastewater treatment process have poor capture ability for heavy metal ions, resulting in a high concentration of heavy metal ions in the treated wastewater, affecting the subsequent treatment of the wastewater. Summary of the invention

[0004] In view of the above problems existing in the prior art, the object of the present invention is to provide a high temperature resistant flocculant and a preparation method thereof.

[0005] The present invention also aims to provide the use of the high temperature resistant flocculant in the treatment of coal gasification process wastewater, which has the advantages of low cost, strong adaptability, high efficiency, etc.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides a method for preparing a high temperature resistant flocculant, comprising the following steps:

[0008] 1) Mixing coal gasification slag with an acid solution, stirring the mixture to react, and separating the liquid phase to obtain a coal gasification slag acid leaching solution;

[0009] 2) adding calcium aluminate to the acid leaching filtrate of the coal gasification slag in step 1) and stirring the mixture thoroughly to react;

[0010] 3) adding 3-mercaptopropyltrimethoxysilane to the reaction solution of step 2) and stirring the mixture thoroughly to react;

[0011] 4) adding ethylenediamine to the reaction solution of step 3) and stirring the reaction thoroughly;

[0012] 5) adding the temperature-responsive polymer, the pH-responsive polymer and the ion concentration-responsive polymer to the reaction solution of step 4) and stirring the mixture to react;

[0013] 6) The reaction solution of step 5) is filtered, dried and ground to obtain the high temperature resistant flocculant.

[0014] In a specific embodiment, the coal gasification slag in step 1) needs to be crushed and sieved, and the particle size after sieving is 150-300 μm;

[0015] The coal gasification slag refers to the solid waste produced after the coal undergoes a chemical reaction with a gasifying agent (such as oxygen, water vapor, etc.) under high temperature and high pressure in a gasifier. Its main components include ash (including silicon oxide, aluminum oxide, iron oxide, etc.), unreacted carbon, metal compounds, sulfides or sulfates, and other trace components;

[0016] The coal gasification slag has no special requirements on its source, for example, bituminous coal, anthracite, lignite, etc. are solid wastes generated after coal gasification.

[0017] In a specific embodiment, the acid solution in step 1) is an acid aqueous solution with a concentration of 100-500 g / L; preferably, the acid is any one or more of hydrochloric acid, sulfuric acid, nitric acid, and hydrofluoric acid.

[0018] In a specific embodiment, the mass ratio of the acid solution to the coal gasification slag in step 1) is 3-7:1.

[0019] In a specific embodiment, the stirring reaction in step 1) is carried out at a temperature of 70-110°C, a stirring speed of 300-500 n / min, and a stirring reaction time of 60-300 min. In this step, an acid solution (such as hydrochloric acid, sulfuric acid or nitric acid, etc.) is used to chemically react with metal oxides and other components in the coal gasification slag to achieve the dissolution and extraction of valuable metals.

[0020] In a specific application, in order to fully extract the effective components in the coal gasification slag, the pickling operation in step 1) can be repeated, for example, the stirring reaction is repeated 1-4 times; after the reaction is completed, the liquid phase can be separated by conventional methods such as filtration.

[0021] In a specific embodiment, in step 2), the mass ratio of the coal gasification slag acid leaching solution to calcium aluminate is 3-6:1.

[0022] In a specific embodiment, in step 2), the stirring reaction is carried out at a temperature of 60-90° C., a stirring speed of 200-300 n / min, and a stirring reaction time of 60-180 min.

[0023] In a specific embodiment, the molar ratio of the 3-mercaptopropyltrimethoxysilane in step 3) to the aluminum ion in the reaction solution of step 2) is 0.5-3:1.

[0024] In a specific embodiment, in step 3), the stirring reaction is carried out at a temperature of 30-60°C, a stirring speed of 150-200 n / min, and a stirring reaction time of 90-150 min.

[0025] In a specific embodiment, the molar ratio of the ethylenediamine in step 4) to the aluminum ions in the reaction solution of step 3) is 0.4-1:1.

[0026] In a specific embodiment, in step 4), the stirring reaction is carried out at a temperature of 30-60°C, a stirring speed of 150-200 n / min, and a stirring reaction time of 50-90 min.

[0027] In a specific embodiment, the temperature-responsive polymer in step 5) is selected from one or more of polyoxyethylene-polyoxypropylene copolymer, poly-N-isopropylacrylamide, poly-N,N-dimethylacrylamide, and polyethylene glycol, preferably poly-N-isopropylacrylamide, with a degree of polymerization of 10,000-25,000; the temperature-responsive polymer can enhance the flocculation effect, provide intelligent regulation capability, improve dispersibility and stability, and can expand the application range of the flocculant by controlling the release behavior;

[0028] Preferably, the mass ratio of the temperature responsive polymer to the reaction solution of step 4) is 1-10%.

[0029] In a specific embodiment, the pH-responsive polymer in step 5) is selected from one or more of polymethacrylic acid, poly(2-vinylpyridine), and poly(4-vinylphenol), preferably polyacrylic acid; the pH-responsive polymer can enhance the flocculation effect, adjust the solubility and dispersibility, improve the flocculent properties and stability, and improve the overall performance through synergistic effect;

[0030] Preferably, the mass ratio of the pH responsive polymer to the reaction solution of step 4) is 1-10%.

[0031] In a specific embodiment, the ion concentration responsive polymer in step 5) is selected from one or more of sodium polyacrylate, sodium polystyrene sulfonate, and polyethyleneimine, preferably sodium polystyrene sulfonate; the ion concentration responsive polymer utilizes the anionic charge provided by it to enhance the flocculation effect, improve the floc characteristics and stability, and adjust the solution properties;

[0032] Preferably, the mass ratio of the ion concentration responsive polymer to the reaction solution of step 4) is 0.1-0.5%.

[0033] In a specific embodiment, in step 5), the stirring reaction is carried out at a temperature of 20-60° C., a stirring speed of 100-200 n / min, and a stirring reaction time of 30-90 min.

[0034] In a specific embodiment, the filtering, drying and grinding in step 6) are conventional operations in the field. Preferably, the drying treatment is: drying in an oven at 80-100°C for 7-10h; preferably, the flocculant particle size obtained by the grinding treatment is 70-100μm.

[0035] In a second aspect, the present invention provides a high temperature resistant flocculant prepared by the above method;

[0036] The flocculant has the advantages of low cost, strong adaptability, high efficiency, etc., and can withstand high temperatures above 150°C.

[0037] In a third aspect, the present invention provides the application of the above-mentioned high temperature resistant flocculant, which can be used in the fields of industrial wastewater treatment, oil fields and oil production operations, electric power industry, etc., and is particularly suitable for coal gasification wastewater treatment.

[0038] Specifically, one application is to use the flocculant of the present invention to treat coal gasification wastewater during the wastewater treatment stage of the coal gasification process.

[0039] The coal gasification wastewater treated with the flocculant of the present invention can achieve a turbidity removal rate of 93.36% and a heavy metal removal rate of 67%.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] The present invention adopts coal gasification slag to prepare flocculant, thus reducing the cost of reagents in the coal gasification process wastewater treatment stage;

[0042] The present invention introduces intelligent polymers composed of temperature-responsive polymers, pH-responsive polymers and ion concentration-responsive polymers, so that the flocculant can automatically adjust its structure and performance according to the reaction temperature, reaction pH and ion concentration to adapt to the complex and changeable wastewater treatment needs, thereby reducing the dependence on reaction conditions, and then reducing the complexity of the wastewater treatment process and the cost of environmental condition control;

[0043] The present invention performs surface activity treatment on the flocculant to improve the ability of the flocculant to capture heavy metal ions, thereby improving the wastewater treatment effect. DETAILED DESCRIPTION

[0044] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] In the embodiments and comparative examples of the present invention, the sources of the main raw materials used are as follows. Unless otherwise specified, other raw materials and reagents were purchased from commercial sources:

[0046] name factory hydrochloric acid Sinopharm Chemical Reagent Co., Ltd. sulfuric acid Sinopharm Chemical Reagent Co., Ltd. Nitric acid Sinopharm Chemical Reagent Co., Ltd. Calcium Aluminate Sinopharm Chemical Reagent Co., Ltd. 3-Mercaptopropyltrimethoxysilane Sinopharm Chemical Reagent Co., Ltd. Ethylenediamine Sinopharm Chemical Reagent Co., Ltd. Polyoxyethylene-polyoxypropylene copolymer Sinopharm Chemical Reagent Co., Ltd. Poly (N-isopropylacrylamide) Sinopharm Chemical Reagent Co., Ltd. Poly (N,N-dimethylacrylamide) Polymer Source Polyethylene glycol Sinopharm Chemical Reagent Co., Ltd. Polymethacrylic acid Sinopharm Chemical Reagent Co., Ltd. Poly(2-vinylpyridine) Sigma Poly (4-vinylphenol) Sigma Sodium polyacrylate Sigma Sodium polystyrene sulfonate Sinopharm Chemical Reagent Co., Ltd. Polyethyleneimine Sinopharm Chemical Reagent Co., Ltd.

[0047] Coal gasification slag: It comes from the solid waste generated by coal gasification in Baling Petrochemical Company. The specific composition is shown in Table 1:

[0048] Table 1 Composition of coal gasification slag

[0049]

[0050] The main analytical methods used in the examples and comparative examples of the present invention are as follows:

[0051] (1) Turbidity test standard method refers to GB 13200-1991;

[0052] (2) The heavy metal content detection method shall refer to GB / T 38596-2020.

[0053] Example 1

[0054] Preparation of high temperature resistant flocculant:

[0055] 1) Mix the coal gasification slag with a 100 g / L hydrochloric acid aqueous solution in a mass ratio of 1:3, and stir the mixture thoroughly. The stirring temperature is 70°C, the stirring speed is 300 n / min, the stirring time is 60 min, and the liquid phase is separated. Repeat the operation 4 times to obtain the coal gasification slag acid leaching solution.

[0056] 2) adding calcium aluminate to the coal gasification slag acid leaching solution of step 1), the mass ratio of the coal gasification slag acid leaching solution to calcium aluminate is 3:1, and stirring the mixture to react. The stirring reaction temperature is 60° C., the stirring speed is 200 n / min, and the stirring reaction time is 60 min.

[0057] 3) adding 3-mercaptopropyltrimethoxysilane to the reaction solution of step 2), wherein the molar ratio of 3-mercaptopropyltrimethoxysilane to aluminum ions in the reaction solution of step 2) is 0.5:1, and stirring the reaction thoroughly. The stirring reaction temperature is 30° C., the stirring speed is 150 n / min, and the stirring reaction time is 90 min;

[0058] 4) adding ethylenediamine to the reaction solution of step 3), wherein the molar ratio of ethylenediamine to aluminum ions in the reaction solution of step 3) is 0.4:1, and stirring the mixture thoroughly. The stirring temperature is 30° C., the stirring speed is 150 n / min, and the stirring time is 50 min;

[0059] 5) adding poly (N-isopropylacrylamide) (temperature responsive polymer), polyacrylic acid (pH responsive polymer) and sodium polystyrene sulfonate (ion concentration responsive polymer) to the reaction solution of step 4), and stirring the mixture to react;

[0060] The mass ratios of poly(N-isopropylacrylamide), poly(acrylic acid) and sodium polystyrene sulfonate to the reaction solution of step 4) are 1%, 1% and 0.1% respectively; the stirring reaction temperature is 50°C, the stirring speed is 100n / min, and the stirring reaction time is 90min;

[0061] 6) The reaction solution of step 5) is filtered, dried in an oven at 80-100° C. for 7 h, and ground into particles with a particle size of 70-100 μm to obtain a high temperature resistant flocculant.

[0062] Example 2

[0063] Preparation of high temperature resistant flocculant:

[0064] 1) Mix the coal gasification slag with a 200 g / L hydrochloric acid aqueous solution in a mass ratio of 1:4, and stir the mixture thoroughly for reaction. The stirring temperature is 80°C, the stirring speed is 350 n / min, the stirring time is 120 min, and the liquid phase is separated. The operation is repeated 4 times to obtain the coal gasification slag acid leaching solution.

[0065] 2) adding calcium aluminate to the coal gasification slag acid leaching solution of step 1), the mass ratio of the coal gasification slag acid leaching solution to calcium aluminate is 4:1, and stirring is fully carried out for reaction, the stirring reaction temperature is 70° C., the stirring speed is 200 n / min, and the stirring reaction time is 90 min.

[0066] 3) adding 3-mercaptopropyltrimethoxysilane to the reaction solution of step 2), wherein the molar ratio of 3-mercaptopropyltrimethoxysilane to the aluminum ion in the reaction solution of step 2) is 1:1, and stirring the reaction thoroughly. The stirring reaction temperature is 40° C., the stirring speed is 180 n / min, and the stirring reaction time is 120 min;

[0067] 4) adding ethylenediamine to the reaction solution of step 3), wherein the molar ratio of ethylenediamine to aluminum ions in the reaction solution of step 3) is 0.6:1, and stirring the mixture thoroughly. The stirring temperature is 40° C., the stirring speed is 180 n / min, and the stirring time is 60 min;

[0068] 5) adding polyethylene glycol, polymethacrylic acid and polyethyleneimine to the reaction solution of step 4) and stirring the mixture to react;

[0069] The mass ratios of polyethylene glycol, polymethacrylic acid and polyethyleneimine to the reaction solution of step 4) are 5%, 5% and 0.2% respectively; the stirring reaction temperature is 60°C, the stirring speed is 100n / min, and the stirring reaction time is 60min;

[0070] 6) The reaction solution of step 5) is filtered, dried in an oven at 80-100° C. for 8 h, and ground into particles with a particle size of 70-100 μm to obtain a high temperature resistant flocculant.

[0071] Example 3

[0072] Preparation of high temperature resistant flocculant:

[0073] 1) Mix the coal gasification slag with a 500 g / L hydrochloric acid aqueous solution in a mass ratio of 1:5, and stir the mixture thoroughly for reaction. The stirring temperature is 80°C, the stirring speed is 400 n / min, the stirring time is 240 min, and the liquid phase is separated. The operation is repeated 4 times to obtain the coal gasification slag acid leaching solution.

[0074] 2) adding calcium aluminate to the coal gasification slag acid leaching solution of step 1), the mass ratio of the coal gasification slag acid leaching solution to calcium aluminate is 4:1, and stirring the mixture to react at a temperature of 80° C., a stirring speed of 250 n / min, and a stirring reaction time of 180 min.

[0075] 3) adding 3-mercaptopropyltrimethoxysilane to the reaction solution of step 2), wherein the molar ratio of 3-mercaptopropyltrimethoxysilane to the aluminum ion in the reaction solution of step 2) is 2:1, and stirring the mixture to react. The stirring temperature is 40° C., the stirring speed is 200 n / min, and the stirring time is 120 min.

[0076] 4) adding ethylenediamine to the reaction solution of step 3), wherein the molar ratio of ethylenediamine to aluminum ions in the reaction solution of step 3) is 1:1, and stirring the mixture thoroughly for reaction at a temperature of 40° C., a stirring speed of 180 n / min, and a stirring reaction time of 80 min;

[0077] 5) adding polyethylene glycol, poly-2-vinylpyridine and sodium polyacrylate to the reaction solution of step 4) and stirring the mixture to react;

[0078] The mass ratios of polyethylene glycol, poly-2-vinylpyridine and sodium polyacrylate to the reaction solution of step 4) are 6%, 8% and 0.4% respectively; the stirring reaction temperature is 60°C, the stirring speed is 180n / min, and the stirring reaction time is 70min;

[0079] 6) The reaction solution of step 5) is filtered, dried in an oven at 80-100° C. for 9 hours, and ground into particles with a particle size of 70-100 μm to obtain a high temperature resistant flocculant.

[0080] Comparative Example 1

[0081] The preparation method was prepared by referring to Example 1, except that the addition of calcium aluminate in step 2) was omitted, the acid leaching filtrate of the coal gasification slag in step 1) was directly used in step 3), and other operations and raw materials remained unchanged to obtain a flocculant.

[0082] Comparative Example 2

[0083] The preparation method was referred to Example 1, except that step 3) of adding 3-mercaptopropyltrimethoxysilane was omitted, the reaction solution of step 2) was directly used in step 4), and other operations and raw materials remained unchanged to obtain a flocculant.

[0084] Comparative Example 3

[0085] The preparation method was carried out in accordance with Example 1, except that the step 4) of adding ethylenediamine was omitted, the reaction solution of step 3) was directly used in step 5), and the other operations and raw materials remained unchanged to obtain a flocculant.

[0086] Comparative Example 4

[0087] The preparation method was referred to Example 1, except that in step 5), poly (N-isopropylacrylamide) (temperature-responsive polymer) was not added, and other operations and raw materials remained unchanged to obtain a flocculant.

[0088] Comparative Example 5

[0089] The preparation method was referred to Example 1, except that no polyacrylic acid (pH responsive polymer) was added in step 5), and other operations and raw materials remained unchanged to obtain a flocculant.

[0090] Comparative Example 6

[0091] The preparation method was referred to Example 1, except that sodium polystyrene sulfonate (ion concentration responsive polymer) was not added in step 5), and other operations and raw materials remained unchanged to obtain a flocculant.

[0092] The flocculants prepared in Examples 1-3 and Comparative Examples 1-6 were used to treat coal gasification wastewater. The treatment method adopted was as follows:

[0093] (1) Take 0.1g of flocculant and dilute it to 100g with water, and stir for 1h;

[0094] (2) Take 200 mL of coal gasification wastewater into a 300 mL hydrothermal reactor and add 10 mL of diluted flocculant;

[0095] (3) hydrothermally treating the above solution at 180°C for 2 h;

[0096] (4) After the hydrothermal treatment, stir at 250 rpm for 2 min;

[0097] (5) Stirring at 250 rpm for 30 s;

[0098] (6) Slowly reduce the speed to 100 rpm and stir for 20 min;

[0099] (7) After standing for 10 min, take the supernatant and measure the turbidity and heavy metal content.

[0100] The test results are shown in Table 2 below.

[0101] Table 2 Comparison of the treatment effects of flocculants prepared in the examples and comparative examples on coal gasification wastewater (180°C)

[0102]

[0103] According to the above treatment method, the flocculant prepared in Example 1 was used to test the effect of different addition amounts on the treatment effect of coal gasification wastewater. The results are shown in Table 3.

[0104] Table 3 Comparison of treatment effects of different amounts of flocculant solution on coal gasification wastewater

[0105]

[0106] Based on the above, the advantages of the present invention are that, when the present invention is used, the present invention adopts coal gasification slag to prepare low-cost aluminum-containing composite flocculants, thereby reducing the flocculant cost in the wastewater treatment stage of the coal gasification process; the present invention introduces intelligent polymers so that the flocculant can automatically adjust its structure and performance according to the reaction temperature, reaction pH and ion concentration to adapt to the complex and changeable coal gasification wastewater treatment needs, thereby reducing the complexity of the wastewater treatment process and the cost increased by controlling environmental conditions; the present invention introduces thiol and amino groups, the thiol group can form a stable complex with heavy metal ions, and the amino group can enhance the electrostatic attraction between the flocculant and the negatively charged pollutant particles, thereby improving the flocculation effect, and can also enhance the solubility and dispersibility of the flocculant, thereby improving the wastewater treatment effect and reducing the amount of flocculant used.

[0107] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

Claims

1. A method for preparing a high temperature resistant flocculant, characterized in that: The following steps are involved: 1) Mixing coal gasification slag with an acid solution, stirring the mixture to react, and separating the liquid phase to obtain a coal gasification slag acid leaching solution; 2) adding calcium aluminate to the acid leaching filtrate of the coal gasification slag in step 1) and stirring the mixture thoroughly to react; 3) adding 3-mercaptopropyltrimethoxysilane to the reaction solution of step 2) and stirring the mixture thoroughly to react; 4) adding ethylenediamine to the reaction solution of step 3) and stirring the reaction thoroughly; 5) adding the temperature-responsive polymer, the pH-responsive polymer and the ion concentration-responsive polymer to the reaction solution of step 4) and stirring the mixture to react; 6) The reaction solution of step 5) is filtered, dried and ground to obtain the high temperature resistant flocculant.

2. The preparation method according to claim 1, characterized in that: Step 1) The coal gasification slag needs to be crushed and sieved, and the particle size after sieving is 150-300 μm; and / or Step 1) The acid solution is an acid aqueous solution with a concentration of 100-500 g / L; Preferably, the acid is any one or more of hydrochloric acid, sulfuric acid, nitric acid, and hydrofluoric acid; and / or Step 1) The mass ratio of the acid solution to the coal gasification slag is 3-7:1; and / or In step 1), the stirring reaction is carried out at a temperature of 70-110° C., a stirring speed of 300-500 n / min, and a stirring reaction time of 60-300 min.

3. The preparation method according to claim 1, characterized in that: Step 2) the mass ratio of the coal gasification slag acid leaching solution to calcium aluminate is 3-6:1; and / or Step 2) The stirring reaction is carried out at a temperature of 60-90° C., a stirring speed of 200-300 n / min, and a stirring reaction time of 60-180 min.

4. The preparation method according to claim 1, characterized in that: The molar ratio of the 3-mercaptopropyltrimethoxysilane in step 3) to the aluminum ion in the reaction solution in step 2) is 0.5-3:1; and / or Step 3) The stirring reaction is carried out at a temperature of 30-60°C, a stirring speed of 150-200 n / min, and a stirring reaction time of 90-150 min.

5. The preparation method according to claim 1, characterized in that: The molar ratio of the ethylenediamine in step 4) to the aluminum ion in the reaction solution in step 3) is 0.4-1:1; and / or Step 4) The stirring reaction is carried out at a temperature of 30-60°C, a stirring speed of 150-200 n / min, and a stirring reaction time of 50-90 min.

6. The preparation method according to claim 1, characterized in that: Step 5) the temperature responsive polymer is selected from one or more of polyoxyethylene-polyoxypropylene copolymer, poly-N-isopropylacrylamide, poly-N,N-dimethylacrylamide, polyethylene glycol, preferably poly-N-isopropylacrylamide, with a degree of polymerization of 10000-25000; Preferably, the mass ratio of the temperature responsive polymer to the reaction solution of step 4) is 1-10%; and / or Step 5) the pH responsive polymer is selected from one or more of polymethacrylic acid, poly(2-vinylpyridine), poly(4-vinylphenol), preferably polyacrylic acid; Preferably, the mass ratio of the pH responsive polymer to the reaction solution of step 4) is 1-10%; and / or Step 5) the ion concentration responsive polymer is selected from one or more of sodium polyacrylate, sodium polystyrene sulfonate, and polyethyleneimine, preferably sodium polystyrene sulfonate; Preferably, the mass ratio of the ion concentration responsive polymer to the reaction solution of step 4) is 0.1-0.5%; and / or Step 5) The stirring reaction is carried out at a temperature of 20-60° C., a stirring speed of 100-200 n / min, and a stirring reaction time of 30-90 min.

7. The preparation method according to claim 1, characterized in that: Step 6) the drying is carried out at a temperature of 80-100°C for a period of 7-10 hours; and / or Step 6) The particle size of the flocculant obtained by the grinding treatment is 70-100 μm.

8. A high temperature resistant flocculant prepared by the method according to any one of claims 1 to 7.

9. Application of the high temperature resistant flocculant prepared by the method according to any one of claims 1 to 7 or the high temperature resistant flocculant according to claim 8 in industrial wastewater treatment, oil field and oil production operations, and electric power industry, especially suitable for coal gasification wastewater treatment.

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