Press filtrate ion removal and conversion recycling slurry preparation method

Abstract

The invention belongs to the field of oil and gas field drilling environment protection, and particularly relates to a pressure filtrate ion removal and conversion recycling slurry preparation method which comprises the following steps: collecting pressure filtrate after chemical gel breaking of water-based slurry; adding an ion remover, and stirring for a certain time to adjust the pH value to 9-10; a filtrate conversion agent is added into the pressure filtrate after ion removal, stirring is conducted for a certain time, the filtrate conversion agent is completely dissolved in the pressure filtrate to form recycling slurry preparation liquid, and the adding amount of the filtrate conversion agent accounts for 0.2%-0.5% of the mass of the pressure filtrate. The negative effect ions mainly including Ca < 2 + >, Mg < 2 + >, Cl <->, SO4 < 2-> and the like can be removed, the rheological parameters and the filtrate reduction performance of drilling base slurry prepared from the pressure filtrate are improved, the involved ion remover and the filtrate conversion agent are good in flocculation effect, stable in flocculation solidification phase, free of removal and capable of being reused for slurry preparation along with the water-based slurry pressure filtrate, and the cost is reduced. And after being converted, the water-based mud press filtrate can completely replace clear water to prepare the drilling base mud, so that the drilling waste is recycled, and the water resource is greatly saved.

Description

Technical Field

[0001] The invention belongs to the field of oil and gas field drilling environment protection, and particularly relates to a slurry preparation method for removing ions from a filtrate and converting and recycling it. Background Art

[0002] The large amount of waste mud generated during drilling construction is one of the main sources of pollution in the oil and gas industry. If it is not treated scientifically and effectively, it will inevitably bring risks to the local environment. At present, the methods for treating waste mud include chemical degelation-solid-liquid separation, component recovery and recycling, chemical solidification treatment, biological treatment, etc. Among them, the chemical degelation-solid-liquid separation method is widely used at drilling construction sites because of its simple construction and simple equipment required.

[0003] The chemical degelling-solid-liquid separation method achieves solid-liquid separation of waste mud. The separated solid phase can be further recycled for the preparation of unburned bricks, road paving soil, etc.; the filtrate has a high mineralization degree, and a large amount of metal ions such as calcium, magnesium, aluminum, iron, as well as chloride ions and sulfate ions will weaken the hydration and dispersion of clay and cannot be reused for slurry preparation. It can only be handed over to a third-party company for treatment and discharge after meeting the standards.

[0004] Due to the huge demand for water at the drilling site, the outsourcing of filtrate treatment has caused a certain degree of waste of water resources. Therefore, removing the negative effect ions in the water-based mud filtrate, reducing the mineralization of the filtrate, and converting the filtrate into a glue with a certain viscosity for back-mixing drilling base mud can not only reduce the drilling construction cost and environmental risks, but also alleviate the current situation of water shortage in the well site. It is a circular development, green and clean technical path. Summary of the invention

[0005] In view of the above problems, the present invention proposes a method for removing ions from a filtrate and converting it for reuse in pulping, the method comprising:

[0006] Collect the filtrate after chemical degelling of water-based mud;

[0007] Add ion remover, stir for a while and adjust pH value to 9-10;

[0008] Add a filtrate converter to the filtrate after deionization, stir for a certain period of time, and make the filtrate converter completely dissolved in the filtrate to form a reuse slurry, wherein the filtrate converter is added in an amount of 0.2%-0.5% of the mass of the filtrate.

[0009] Furthermore, the ion remover and the filtrate are fully stirred at a stirring speed of 50-100 r / min and a stirring time of 15-30 minutes.

[0010] Furthermore, the stirring speed of the filtrate after the ions are fully stirred and the filtrate conversion agent is 50-100 r / min, and the stirring time is 2-4 hours.

[0011] Furthermore, the ion remover includes one of sodium carbonate, sodium hydroxide, sodium nitrilotriacetate, pentasodium diethylenetriaminepentaacetate, or any combination thereof.

[0012] Furthermore, the preparation of the filtrate conversion agent comprises:

[0013] Add deionized water into the reaction vessel and heat the water bath to 80-90°C;

[0014] Add acrylamide, hydrophobic monomer and acrylic acid in the deionized water in sequence, and adjust the pH value to 7-8 with sodium hydroxide solution;

[0015] The water bath temperature is adjusted to 50-60° C., an initiator and a complexing agent are sequentially added to the adjusted weakly alkaline solution, argon is introduced, and the reaction is carried out for 8-12 hours to obtain a filtrate conversion agent.

[0016] Furthermore, the volume mass ratio of the deionized water, acrylamide, hydrophobic monomer and acrylic acid is 300-500 mL: 31.2-46.8 g: 0.8-1.2 g: 21.6-32.4 g.

[0017] Furthermore, the volume mass ratio of the deionized water, the initiator and the complexing agent is 300-500 mL: 0.09-0.15 g: 0.03-0.05 g.

[0018] Furthermore, the initiator includes one of potassium persulfate, sodium persulfate, ammonium persulfate, or any combination thereof.

[0019] Furthermore, the complexing agent includes one or a combination of any of disodium ethylenediaminetetraacetate, tartaric acid or citric acid.

[0020] Furthermore, the preparation of the hydrophobic monomer comprises:

[0021] Dissolve dodecyl tert-amine and allyl chloride in acetone, stir and heat to 50-60° C., reflux for 10-12 hours, and dry to obtain a hydrophobic monomer.

[0022] Furthermore, the volume mass ratio of the acetone, dodecanederylamine and allyl chloride is 100-120 mL: 110-130 g: 45-55 g.

[0023] Aiming at the problems of high mineralization of water-based mud filter press and poor performance of back-matching drilling base mud, the present invention proposes a method for removing ions from filter press and converting it for back-matching, removing Ca 2+ Mg2+ , Cl - 、SO 4 2- The negative effect ions mainly including the above are improved, and the rheological parameters and filtration loss reduction performance of the filtrate for mixing with the drilling base slurry are improved. The ion removal agent and filtrate converter involved have good flocculation effect, and the flocculation solid phase is stable and does not need to be removed. It can be mixed with the water-based mud filtrate for mixing with the drilling base slurry, so that the water-based mud filtrate can completely replace clean water for mixing with the drilling base slurry after conversion, so as to realize the recycling of drilling waste and greatly save water resources. The method for removing ions and converting the water-based mud filtrate for mixing with the drilling base slurry of the present invention is simple and does not increase the equipment cost. The ion removal agent and filtrate converter involved are safe and non-toxic, and will not cause secondary pollution to the environment.

[0024] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 The schematic diagram of the process of removing ions from the filtrate and converting it for reuse in pulping in an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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.

[0028] The present invention provides a method for removing ions from a filtrate and converting it for reuse in pulping. Figure 1 The schematic diagram of the process of removing ions from the filtrate and converting it for reuse in pulping in an embodiment of the present invention is shown. Figure 1The method comprises collecting the filtrate after chemical degelling of water-based mud; adding an ion remover, stirring for a certain time to adjust the pH value to 9-10; adding a filtrate converter to the filtrate after ion removal, stirring for a certain time, so that the filtrate converter is completely dissolved in the filtrate to form a reuse slurry, wherein the filtrate converter is added in an amount of 0.2%-0.5% of the mass of the filtrate.

[0029] Specifically, in the embodiment of the present invention, the stirring speed for fully stirring the ion remover and the filtrate is 50-100 r / min, and the stirring time is 15-30 minutes.

[0030] Specifically, in the embodiment of the present invention, the stirring speed of the filtrate after the ions are fully stirred and the filtrate converter is 50-100 r / min, and the stirring time is 2-4 hours.

[0031] Specifically, in order to prevent the use of degumming agents and inorganic salts in the formation itself during the treatment of drilling waste fluid, resulting in a high content of cations such as calcium, magnesium, aluminum, and iron in the filtrate, which weakens the hydration and dispersion of the liquid and clay, and the filtrate cannot be reused to prepare new slurry. The ion remover in the embodiment of the present invention includes one or a combination of any of sodium carbonate, sodium hydroxide, sodium nitrilotriacetate, and pentasodium diethylenetriamine pentaacetate. The selected reagents can better remove calcium, magnesium, aluminum, and iron ions, and will not affect the reuse of the filtrate.

[0032] In the embodiment of the present invention, the preparation of the filtrate conversion agent is also specifically described:

[0033] Add deionized water into the reaction vessel and heat the water bath to 80-90°C;

[0034] Add acrylamide, hydrophobic monomer and acrylic acid in the deionized water in sequence, and adjust the pH value to 7-8 with sodium hydroxide solution;

[0035] The water bath temperature is adjusted to 50-60° C., an initiator and a complexing agent are sequentially added to the adjusted weakly alkaline solution, argon is introduced, and the reaction is carried out for 8-12 hours to obtain a filtrate conversion agent.

[0036] Specifically, in the embodiment of the present invention, in order to increase the relative molecular weight of the obtained copolymer and improve the slurry preparation effect of the filtrate, the volume mass ratio of the deionized water, acrylamide, hydrophobic monomer and acrylic acid is 300-500 mL: 31.2-46.8 g: 0.8-1.2 g: 21.6-32.4 g.

[0037] Preferably, in the embodiment of the present invention, the mass ratio of acrylamide, hydrophobic monomer and acrylic acid is 39:1:27, the ratio of initiator is 0.18% of the total monomer amount, and the amount of complexing agent added is 0.01% of the amount of deionized water.

[0038] Specifically, the volume mass ratio of the deionized water, the initiator, and the complexing agent is 300-500 mL: 0.09-0.15 g: 0.03-0.05 g.

[0039] Specifically, the complexing agent includes one or a combination of any of disodium ethylenediaminetetraacetate, tartaric acid or citric acid.

[0040] Specifically, the initiator includes one of potassium persulfate, sodium persulfate, ammonium persulfate, or any combination thereof.

[0041] In the embodiment of the present invention, the preparation of the hydrophobic monomer is also specifically described. Dodecyl tertiary amine and allyl chloride are dissolved in acetone, stirred and heated to 50-60° C., refluxed for 10-12 hours, and dried to obtain the hydrophobic monomer.

[0042] Specifically, in the embodiment of the present invention, in order to avoid reaction reflux cycle and facilitate the subsequent drying of the hydrophobic monomer, the volume mass ratio of the acetone, dodecyl tert-amine and allyl chloride is 100-120 mL: 110-130 g: 45-55 g.

[0043] Preferably, in order to increase the yield of the prepared hydrophobic monomer, the molar ratio of allyl chloride to dodecyl tertiary amine is in the range of 1.15:1 to 1.4:1.

[0044] The present invention also specifically describes the method for removing ions from the filtrate and converting the filtrate for reuse and the performance of the reused slurry through multiple embodiments.

[0045] Embodiment 1

[0046] In Example 1 of the present invention, 1000 mL of water-based mud filtrate is selected, the ion remover is selected from sodium carbonate, the initiator is selected from potassium persulfate, and the complexing agent is selected from tartaric acid.

[0047] The specific steps include:

[0048] Collect 1000 mL of water-based mud filtrate and add it into a beaker. Add ion remover into the beaker to adjust the pH of the filtrate to 9, and stir at 50 rpm for 15 minutes.

[0049] Add filtrate conversion agent into the beaker in an amount of 0.2% of the mass of the filtrate, and stir at a speed of 50 rpm for 2 hours to form a reuse slurry.

[0050] In Example 1 of the present invention, the preparation method of the filtrate converter is as follows: 300 mL of deionized water is added to the reactor, and the water bath is heated to 80° C.; 31.2 g of acrylamide, 0.8 g of a hydrophobic monomer, and 21.6 g of acrylic acid are added in sequence, and sodium hydroxide is slowly added to adjust the pH value of the solution to 7; the water bath temperature is adjusted to 50° C., and 0.09 g of potassium persulfate and 0.03 g of tartaric acid are added to the solution in sequence, argon is introduced, and the reaction is performed for 8 hours to obtain a filtrate converter.

[0051] In Example 1 of the present invention, the preparation method of the hydrophobic monomer is as follows: 110 g of dodecyl tert-amine and 45 g of allyl chloride are dissolved in 100 mL of acetone, the mixture is stirred and heated to 50° C., refluxed for 10 hours, and dried at 40° C.

[0052] Embodiment 2

[0053] In the second embodiment of the present invention, 1000 mL of water-based mud filtrate is selected, the ion remover is selected from sodium hydroxide, the initiator is selected from potassium persulfate, and the complexing agent is selected from citric acid.

[0054] The specific steps include:

[0055] Collect 1000 mL of water-based mud filtrate and add it into a beaker. Add ion remover into the beaker to adjust the pH of the filtrate to 9, and stir at 75 rpm for 20 minutes.

[0056] Add filtrate conversion agent into the beaker in an amount of 0.3% of the mass of the filtrate, and stir at a speed of 50 rpm for 3 hours to form a reuse slurry.

[0057] In Example 2 of the present invention, the preparation method of the filtrate converter is as follows: 350 mL of deionized water is added to the reactor, and the water bath is heated to 80 ° C; 39 g of acrylamide, 0.9 g of hydrophobic monomer, and 27 g of acrylic acid are added in sequence, and sodium hydroxide is slowly added to adjust the pH value of the solution to 7; the water bath temperature is adjusted to 55 ° C, and 0.12 g of potassium persulfate and 0.04 g of citric acid are added to the solution in sequence, argon is introduced, and the reaction is performed for 8 hours to obtain a filtrate converter.

[0058] In Example 2 of the present invention, the preparation method of the hydrophobic monomer is as follows: 120 g of dodecyl tert-amine and 50 g of allyl chloride are dissolved in 110 mL of acetone, the mixture is stirred and heated to 55° C., refluxed for 10 hours, and dried at 40° C.

[0059] Embodiment 3

[0060] In the third embodiment of the present invention, 1000 mL of water-based mud filtrate is selected, the ion remover is selected from sodium nitrilotriacetate, the initiator is selected from sodium persulfate, and the complexing agent is selected from disodium ethylenediaminetetraacetate.

[0061] The specific steps include:

[0062] Collect 1000 mL of water-based mud filtrate and add it into a beaker. Add ion remover into the beaker to adjust the pH of the filtrate to 10, and stir at 75 rpm for 25 minutes.

[0063] Add filtrate conversion agent into the beaker in an amount of 0.4% of the mass of the filtrate, and stir at a speed of 75 rpm for 3 hours to form a reuse slurry.

[0064] In Example 3 of the present invention, the preparation method of the filtrate converter is as follows: 400 mL of deionized water is added to the reactor, and the water bath is heated to 85 ° C; 39 g of acrylamide, 1 g of a hydrophobic monomer, and 27 g of acrylic acid are added in sequence, and sodium hydroxide is slowly added to adjust the pH value of the solution to 8; the water bath temperature is adjusted to 55 ° C, and 0.15 g of sodium persulfate and 0.03 g of disodium ethylenediaminetetraacetate are added to the solution in sequence, argon is introduced, and the reaction is performed for 10 hours to obtain a filtrate converter.

[0065] In Example 3 of the present invention, the preparation method of the hydrophobic monomer is as follows: 120 g of dodecyl amine and 55 g of allyl chloride are dissolved in 110 mL of acetone, the mixture is stirred and heated to 60° C., refluxed for 12 hours, and dried at 40° C.

[0066] Embodiment 4

[0067] In the fourth embodiment of the present invention, 1000 mL of water-based mud filtrate is selected, the ion remover is selected from pentasodium diethylenetriaminepentaacetate, the initiator is selected from ammonium persulfate, and the complexing agent is selected from disodium ethylenediaminetetraacetate.

[0068] The specific steps include:

[0069] Collect 1000 mL of water-based mud filtrate and add it into a beaker. Add ion remover into the beaker to adjust the pH of the filtrate to 10, and stir at 100 rpm for 30 minutes.

[0070] Add filtrate conversion agent into the beaker in an amount of 0.5% of the mass of the filtrate, and stir at a speed of 100 rpm for 3 hours to form a reuse slurry.

[0071] In Example 4 of the present invention, the preparation method of the filtrate converter is as follows: 450 mL of deionized water is added to the reactor, and the water bath is heated to 90 ° C; 39 g of acrylamide, 1.1 g of a hydrophobic monomer, and 27 g of acrylic acid are added in sequence, and sodium hydroxide is slowly added to adjust the pH value of the solution to 8; the water bath temperature is adjusted to 60 ° C, and 0.12 g of ammonium persulfate and 0.04 g of disodium ethylenediaminetetraacetate are added to the solution in sequence, argon is introduced, and the reaction is performed for 10 hours to obtain a filtrate converter.

[0072] In Example 4 of the present invention, the preparation method of the hydrophobic monomer is as follows: 130 g of dodecyl amine and 50 g of allyl chloride are dissolved in 120 mL of acetone, the mixture is stirred and heated to 50° C., refluxed for 12 hours, and dried at 40° C.

[0073] Embodiment 5

[0074] In Example 5 of the present invention, 1000 mL of water-based mud filtrate is selected, the ion remover is selected from a mixture of sodium carbonate and sodium nitrilotriacetate, the mass ratio of sodium carbonate to sodium nitrilotriacetate in the ion remover is 1:1, the initiator is selected from ammonium persulfate, and the complexing agent is selected from disodium ethylenediaminetetraacetate.

[0075] The specific steps include:

[0076] Collect 1000 mL of water-based mud filtrate and add it into a beaker. Add ion remover into the beaker to adjust the pH of the filtrate to 10, and stir at 100 rpm for 20 minutes.

[0077] Add filtrate conversion agent into the beaker in an amount of 0.2% of the mass of the filtrate, and stir at a speed of 100 rpm for 4 hours to form a reuse slurry.

[0078] In Example 5 of the present invention, the preparation method of the filtrate converter is as follows: 500 mL of deionized water is added to the reactor, and the water bath is heated to 90 ° C; 46.8 g of acrylamide, 1.2 g of a hydrophobic monomer, and 32.4 g of acrylic acid are added in sequence, and sodium hydroxide is slowly added to adjust the pH value of the solution to 8; the water bath temperature is adjusted to 60 ° C, and 0.15 g of ammonium persulfate and 0.05 g of disodium ethylenediaminetetraacetate are added to the solution in sequence, argon is introduced, and the reaction is performed for 12 hours to obtain a filtrate converter.

[0079] In Example 5 of the present invention, the preparation method of the hydrophobic monomer is as follows: 130 g of dodecyl amine and 55 g of allyl chloride are dissolved in 120 mL of acetone, the mixture is stirred and heated to 60° C., refluxed for 12 hours, and dried at 40° C.

[0080] In the embodiment of the present invention, clean water and filtrate are used as comparative examples to illustrate the performance of the filtrate ion removal and conversion and reuse slurry preparation method in the embodiment of the present invention. In the embodiment of the present invention, the performance of the slurry prepared by filtrate, clean water and Examples 1-5 is compared for reuse to prepare drilling base slurry, and the performance includes rheological parameters and filtration loss performance of filtrate reuse for drilling base slurry, and the rheological parameters are selected from AV-Apparent Viscosity-apparent viscosity (mPa·s), PV-Plastic Viscosity-plastic viscosity (mPa·s), YP-Yield Point-dynamic shear force (Pa), and the filtration loss performance is determined by low temperature and low pressure filtration loss (API Static Filtration Loss-API filtration loss (mL)).

[0081] In the embodiments of the present invention, 5% (mass fraction) of white clay for drilling site slurry preparation is added to the reuse slurry formed in Examples 1, 2, 3, 4, and 5 and the clean water, and 0.2% (mass fraction) of soda ash is added, and the mixture is stirred at a high speed of 11000 r / min for 20 minutes. After closed curing at 25±1°C for 24 hours, the rheological properties at room temperature and the low-temperature and low-pressure API filtration loss of the suspension are determined by a six-speed rotational viscometer and a medium-pressure filtration tester in accordance with the recommended method in the national standard GB / T16783.1-2020 "Field Test of Drilling Fluids in Petroleum and Natural Gas Industry Part 1: Water-Based Drilling Fluids". The experimental results are shown in Table 1.

[0082] Table 1 Comparison of the performance of the base slurry prepared by the filtrate, clean water and the slurry prepared in each embodiment for reuse in preparing the drilling slurry

[0083]

[0084] In the embodiments of the present invention, it can be seen from the two comparative examples of the filtrate and the clean water that when the filtrate is mixed with clay and soda ash to form a fluid, the apparent viscosity, plastic viscosity and dynamic shear force of the mixed fluid are all below 5, and when the filtrate is used for mixing, the low-temperature and low-pressure API filtration loss is the total filtration loss; when clean water is mixed with clay and soda ash to form a fluid, the apparent viscosity, plastic viscosity and dynamic shear force of the mixed fluid are 17.5mPa·s, 8mPa·s and 9.5Pa respectively, and the API filtration loss is 18ml; when the fluids of Examples 1-5 of the present invention are mixed with clay and soda ash, the apparent viscosities of Examples 1-5 are all greater than the apparent viscosity of clean water as the mixed fluid, When the fluid in Example 5 of the present invention is used for mixing, the apparent viscosity increases by more than 37%; the plastic viscosity of Examples 1-5 is greater than / equal to the plastic viscosity of clean water as the mixed fluid, and when the fluids in Examples 4 and 5 of the present invention are used for mixing, the plastic viscosity increases by 50%; the dynamic shear force of Examples 1-5 is greater than the dynamic shear force of clean water as the mixed fluid, and when the fluid in Example 3 of the present invention is used for mixing, the dynamic shear force increases by more than 42%; the API filtration loss of Examples 1-5 is less than the API filtration loss of clean water as the mixed fluid, and when the fluids in Examples 3, 4, and 5 of the present invention are used for mixing, the API filtration loss decreases by 22%. Therefore, the reused slurry obtained by the method for removing ions from the filtrate and converting the reused slurry can not only replace clean water to prepare drilling base slurry, realize the reuse of drilling waste, and greatly save water resources, but also when the reused slurry in the embodiment of the present invention is used to measure the room temperature rheological properties and low-temperature and low-pressure API filtration loss of the suspension using a six-speed rotary viscometer and a medium-pressure filtration loss meter, the rheological parameters and filtration loss performance of the filtrate reused in the drilling base slurry are greatly improved compared with the clean water configuration.

[0085] Aiming at the problems of high mineralization of water-based mud filter press and poor performance of back-matching drilling base mud, the present invention proposes a method for removing ions from filter press and converting it for back-matching, removing Ca 2+ Mg 2+ , Cl - 、SO 4 2- The negative effect ions mainly including the above are improved, and the rheological parameters and filtration loss reduction performance of the filtrate for mixing with the drilling base slurry are improved. The ion removal agent and filtrate converter involved have good flocculation effect, and the flocculation solid phase is stable and does not need to be removed. It can be mixed with the water-based mud filtrate for mixing with the drilling base slurry, so that the water-based mud filtrate can completely replace clean water for mixing with the drilling base slurry after conversion, so as to realize the recycling of drilling waste and greatly save water resources. The method for removing ions and converting the water-based mud filtrate for mixing with the drilling base slurry of the present invention is simple and does not increase the equipment cost. The ion removal agent and filtrate converter involved are safe and non-toxic, and will not cause secondary pollution to the environment.

[0086] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for removing ions from a filtrate and converting it for reuse, characterized in that: The method comprises: Collect the filtrate after chemical degelling of water-based mud; Add ion remover, stir for a while and adjust pH value to 9-10; Add a filtrate converter to the filtrate after deionization, stir for a certain period of time, and make the filtrate converter completely dissolved in the filtrate to form a reuse slurry, wherein the filtrate converter is added in an amount of 0.2%-0.5% of the mass of the filtrate.

2. The method for removing ions from press filtrate and converting it for reuse according to claim 1, characterized in that: The ion remover and the filtrate are fully stirred at a stirring speed of 50-100 r / min and a stirring time of 15-30 minutes.

3. The method for removing ions from press filtrate and converting it for reuse according to claim 1 or 2, characterized in that: The stirring speed of the filtrate and the filtrate converter after the ions are fully stirred is 50-100 r / min, and the stirring time is 2-4 hours.

4. The method for removing ions from press filtrate and converting it for reuse according to claim 1, characterized in that: The ion remover includes one of sodium carbonate, sodium hydroxide, sodium nitrilotriacetate, pentasodium diethylenetriaminepentaacetate, or any combination thereof.

5. The method for removing ions from press filtrate and converting it for reuse according to claim 1, characterized in that: The preparation of the filtrate conversion agent comprises: Add deionized water into the reaction vessel and heat the water bath to 80-90°C; Add acrylamide, hydrophobic monomer and acrylic acid to the deionized water in sequence, and adjust the pH value to 7-8 with a sodium hydroxide solution; The water bath temperature is adjusted to 50-60° C., an initiator and a complexing agent are sequentially added to the adjusted weakly alkaline solution, argon is introduced, and the reaction is carried out for 8-12 hours to obtain a filtrate conversion agent.

6. The method for removing ions from press filtrate and converting it for reuse according to claim 5, characterized in that: The volume mass ratio of the deionized water, acrylamide, hydrophobic monomer and acrylic acid is 300-500 mL: 31.2-46.8 g: 0.8-1.2 g: 21.6-32.4 g.

7. The method for removing ions from press filtrate and converting it for reuse according to claim 5, characterized in that: The volume mass ratio of the deionized water, the initiator and the complexing agent is 300-500 mL: 0.09-0.15 g: 0.03-0.05 g.

8. The method for removing ions from press filtrate and converting it for reuse according to claim 5, characterized in that: The initiator includes one of potassium persulfate, sodium persulfate, ammonium persulfate or any combination thereof.

9. The method for removing ions from press filtrate and converting it for reuse according to claim 5, characterized in that: The complexing agent includes one or a combination of any of disodium ethylenediaminetetraacetate, tartaric acid or citric acid.

10. The method for removing ions from press filtrate and converting it for reuse according to claim 5 or 6, characterized in that: The preparation of the hydrophobic monomer comprises: Dissolve dodecyl tertiary amine and allyl chloride in acetone, stir and heat to 50-60° C., reflux for 10-12 hours, and dry to obtain a hydrophobic monomer.

11. The method for removing ions from press filtrate and converting it for reuse according to claim 10, characterized in that: The volume mass ratio of the acetone, dodecanederylamine and allyl chloride is 100-120 mL: 110-130 g: 45-55 g.

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