Scale inhibitor for wet-process phosphoric acid production device as well as preparation method and application of scale inhibitor
By using carbon point scale inhibitors prepared from sugarcane bagasse, combined with AMPS and MPEG-MA, a multi-level scale inhibitor structure was constructed, which solved the problem of scale inhibitor failure in strong acid environment in wet phosphoric acid production. It achieved efficient inhibition of calcium sulfate and fluorosilicate scale, and improved the stability and economic benefits of the production unit.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUIZHOU LIUWEI NEW ENERGY CO LTD
- Filing Date
- 2026-01-14
- Publication Date
- 2026-04-10
AI Technical Summary
Existing scale inhibitors fail in the strong acid environment during wet phosphoric acid production, failing to effectively inhibit calcium sulfate and fluorosilicate scale. Furthermore, their insufficient physical stability leads to severe scaling on equipment, affecting production efficiency and equipment lifespan.
A carbon point scale inhibitor was prepared using sugarcane bagasse as a carbon source. By introducing AMPS, a functional monomer containing sulfonic acid groups, and grafting long-chain polyethylene glycol MPEG-MA, a multi-level scale inhibitor was constructed. Combined with ammonium citrate and sodium alkylbenzene sulfonate, a scale inhibitor with high ionization and steric hindrance effect was formed under strong acid environment.
It significantly improved the scale inhibition rate to 96%, effectively inhibited calcium sulfate and fluorosilicate scale, extended the cleaning cycle of heat exchangers and pipelines, achieved long-term stable operation, and utilized biomass resources to reduce raw material costs.
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Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of water treatment, in particular to a scale inhibitor for a wet-process phosphoric acid production device, a preparation method and application thereof. BACKGROUND
[0002] Wet-process phosphoric acid is the core process for the industrial production of phosphate fertilizer, phosphate and refined phosphoric acid. In the production, heating and concentration and pipeline transportation process of wet-process phosphoric acid, due to the complex composition of raw material phosphate rock, the acid system is rich in high-concentration P2O5, SO4 2- , F - , Ca 2+ , Mg 2+ , Fe 3+ , Al 3+ and other ions. This highly supersaturated complex electrolyte system is prone to form a hard scale layer on the heat exchange pipe, evaporation tank wall and inner wall of the conveying pipeline when heated and concentrated. The scale components in the wet-process phosphoric acid system are extremely diverse, not only including common calcium sulfate (gypsum), but also containing a large amount of sodium fluorosilicate, potassium fluorosilicate and complex phosphate scale. The rapid accumulation of these scales will have multiple negative effects: energy efficiency is greatly reduced: scale causes heat resistance to increase, and heat transfer efficiency decreases significantly, thereby causing energy consumption to surge. Equipment wear is intensified: the presence of scale layer easily causes pipeline blockage and intensifies local corrosion of equipment. Production continuity is blocked: severe scaling forces the production line to frequently stop for chemical or mechanical cleaning, which seriously restricts the long-period stable operation of the production device. At present, adding a chemical scale inhibitor is the main means to prevent and control scaling, but the existing technology still faces the following key challenges in actual application: failure in a strong acid environment: the pH value of the wet-process phosphoric acid system is usually less than 1, and the carboxyl group of the traditional polycarboxylic acid scale inhibitor (such as polyacrylic acid) is prone to protonation in a strong acid, resulting in loss of charge repulsion and chelation ability, and a significant decline in scale inhibition efficiency. Single component response: existing scale inhibitors are mostly designed for calcium ion scale, while the unique fluorosilicate scale (silicon-fluorine scale) in wet-process phosphoric acid is often difficult to effectively inhibit. Insufficient physical stability: the concentration process is accompanied by high temperature (above 80℃) and high shear force, and ordinary linear polymers are prone to thermal degradation or chain curling, and cannot maintain a stable protective layer at the heat exchange interface. Although carbon dots (CQDs) as a kind of nanomaterial with rich surface functional groups and excellent chemical stability show potential in the field of scale inhibition, how to use cheap biomass resources to prepare high-performance carbon dots at low cost, and how to build a multi-level structure composite material that can not only resist strong acid corrosion, but also specifically inhibit complex silicon-fluorine scale, are still key technical problems to be solved in the current wet-process phosphoric acid scale inhibition field. SUMMARY
[0003] In order to solve the problems in the prior art, the present application provides a scale inhibitor for a wet-process phosphoric acid production device, a preparation method and application thereof.
[0004] The present application is realized by the following technical solutions:
[0005] A scale inhibitor for a wet-process phosphoric acid production device, comprising the following components in parts by weight: ammonium citrate 40 parts; sodium alkyl benzene sulfonate 2 parts; and carbon dot scale inhibitor 5-15 parts.
[0006] Further, the preparation method of the carbon dot scale inhibitor comprises the following steps:
[0007] 1) Preparation of sugarcane carbon dots: weigh sugarcane residue powder, disperse it in deionized water, and perform pyrolysis reaction at 200°C for 10 hours. After the reaction is completed, cool, centrifuge, and take the supernatant. After filtration, place it in a dialysis bag with a molecular weight cut-off of 1000 Da for dialysis for 48 hours, and freeze-dry to obtain the sugarcane carbon dots.
[0008] 2) Vinyl modification: take the sugarcane carbon dot solution, add sodium carbonate to adjust the pH to 9.0, add hydroquinone polymerization inhibitor and glycidyl methacrylate (GMA), and react at 45°C in the dark for 12 hours. The product is washed with anhydrous ethanol and then redispersed in water for use.
[0009] 3) Core copolymerization: dissolve N-isopropyl acrylamide (NIPAM), 2-acrylamido-2-methylpropanesulfonic acid (AMPS), and crosslinking agent N,N'-methylenebisacrylamide (MBA) in deionized water, add the modified carbon dot dispersion prepared in step 2), and remove dissolved oxygen by passing nitrogen gas.
[0010] 4) Initiation and grafting: add ammonium persulfate and tetramethyl ethylenediamine, initiate polymerization at 30°C for 2 hours, then slowly drop in polyethylene glycol methyl ether methacrylate (MPEG-MA), and continue to react at 50°C for 8 hours.
[0011] 5) Purification: heat the reaction solution to 70°C, filter while hot and wash with 70°C hot water to remove free polyethylene glycol, redisperse and freeze-dry to obtain the carbon dot scale inhibitor.
[0012] Further, in step 1), the ratio of the amount of sugarcane residue powder to deionized water is 2.0g:60mL.
[0013] Further, in step 2), the amount of hydroquinone is 1.5mg, and the amount of glycidyl methacrylate is 0.71g.
[0014] Further, in step 3), the amounts of the components are as follows: NIPAM 2.26g, AMPS 1.04g, and MBA 0.06g.
[0015] Further, in step 4), the molecular weight Mn of the polyethylene glycol methyl ether methacrylate is about 950, and the dropwise addition amount is 1.5 g.
[0016] Further, when the content of the carbon dot scale inhibitor in the whole formula is 15 parts, the scale inhibition rate thereof in the simulated wet-process phosphoric acid mixed acid solution reaches 96%.
[0017] The application further provides a preparation method of the scale inhibitor for a wet-process phosphoric acid production device.
[0018] The application further provides application of the scale inhibitor for a wet-process phosphoric acid production device in inhibiting calcium sulfate scale and fluorosilicate scale in a wet-process phosphoric acid concentration process.
[0019] Compared with the prior art, the application has the following advantages and beneficial effects: by introducing a functional monomer (AMPS) containing a sulfonic acid group, the application solves the technical problem of deactivation of a traditional polycarboxylic acid scale inhibitor due to protonation of a carboxyl group by using the characteristic that a sulfonic acid group can remain highly ionized in an extremely low pH (<1) environment. A three-dimensional protective layer with high solvation is constructed by grafting a long-chain polyethylene glycol (MPEG-MA) on the surface of carbon dots. This multi-level structure not only inhibits nucleation through charge repulsion, but also blocks the growth and adhesion of crystal nuclei through a strong steric hindrance effect, so that the scale inhibition rate is increased from less than 50% of a traditional material to 96%. The application not only has excellent inhibiting effect on calcium sulfate scale, but also has excellent broad-spectrum inhibiting ability for specific sodium fluorosilicate, potassium fluorosilicate and other silicon-fluorine scale in wet-process phosphoric acid, thereby significantly prolonging the cleaning cycle of a heat exchanger and a pipeline. The application uses waste sugarcane residue as a carbon source, realizes high-value utilization of biomass resources, and has a mild preparation process, low raw material cost, good environmental benefits and economic feasibility. Through scientific compounding with ammonium citrate and sodium alkylbenzenesulfonate, the scale inhibitor has excellent dispersibility and permeability in a complex and supersaturated phosphoric acid mixed acid system, can effectively prevent scale deposition on the surface of equipment, and ensures long-period stable operation of a device. DETAILED DESCRIPTION
[0020] In order to make the purpose, technical scheme and advantages of the application clearer, further detailed description of the application is made below in combination with examples, and the illustrative embodiments of the application and the description thereof are only used to explain the application, and do not limit the application.
[0021] Example 1
[0022] A scale inhibitor for a wet-process phosphoric acid production device includes, by weight parts, 40 parts of ammonium citrate, 2 parts of sodium alkylbenzenesulfonate, and 5 parts of a carbon dot scale inhibitor.
[0023] The preparation method of the carbon dot scale inhibitor includes the following steps:
[0024] Step S1: 2.0 g of bagasse powder was weighed and dispersed in 60 mL of deionized water, and after stirring uniformly, it was transferred to a 100 mL polytetrafluoroethylene-lined high-pressure reaction kettle; the reaction kettle was placed in a constant-temperature air oven, and pyrolysis reaction was carried out at 200℃ for 10 hours; after the reaction was completed, it was naturally cooled to room temperature, and the obtained dark brown solution was centrifuged at 10,000 r / min for 15 minutes, and the supernatant was taken; the supernatant was filtered through a 0.22 μm microporous filter membrane in turn, and was placed in a dialysis bag with a molecular weight cut-off of 1000 Da for dialysis for 48 hours, and the deionized water was replaced every 6 hours; after freeze-drying, bagasse carbon dots were obtained;
[0025] Step S2: 20 mL of the bagasse carbon dot solution (5 mg / mL) prepared in step S1 was taken, 0.2 g of sodium carbonate was added to adjust the pH to 9.0; 1.5 mg of hydroquinone and 0.71 g of glycidyl methacrylate (GMA) were added; the reaction was carried out at 45℃ for 12 hours in the dark; the reaction product was precipitated with anhydrous ethanol, centrifuged and washed 3 times, and then dispersed in 10 mL of deionized water for standby.
[0026] Step S3: 2.26 g of NIPAM, 1.04 g of 2-acrylamido-2-methylpropanesulfonic acid (AMPS) and 0.06 g of crosslinking agent MBA were dissolved in 30 mL of deionized water; add all the modified carbon dot dispersion prepared in step S2, and pass nitrogen for 40 minutes; 22 mg of ammonium persulfate and 15 μL of tetramethyl ethylenediamine were added; the polymerization reaction was initiated at 30℃ for 2 hours;
[0027] Step S4: To the system being reacted in step S3, 1.5 g of polyethylene glycol methyl ether methacrylate (MPEG-MA, Mn≈950) was added at a uniform speed; the reaction kettle was heated to 50℃, and the reaction was continued for 8 hours; the reaction liquid was heated to 70℃, and then filtered and washed with 70℃ hot water 3 times; finally, the product was redispersed in cold water and freeze-dried to obtain a carbon dot scale inhibitor.
[0028] Example 2
[0029] A scale inhibitor for a wet-process phosphoric acid production device, by weight parts, includes: ammonium citrate 40 parts, sodium alkyl benzene sulfonate 2 parts, and carbon dot scale inhibitor 10 parts;
[0030] The preparation method of the carbon dot scale inhibitor comprises the following steps:
[0031] Step S1: 2.0 g of bagasse powder was weighed and dispersed in 60 mL of deionized water, and after stirring uniformly, it was transferred to a 100 mL polytetrafluoroethylene-lined high-pressure reaction kettle; the reaction kettle was placed in a constant-temperature air oven, and pyrolysis reaction was carried out at 200℃ for 10 hours; after the reaction was completed, it was naturally cooled to room temperature, and the obtained dark brown solution was centrifuged at 10,000 r / min for 15 minutes, and the supernatant was taken; the supernatant was filtered through a 0.22 μm microporous filter membrane in turn, and was placed in a dialysis bag with a molecular weight cut-off of 1000 Da for dialysis for 48 hours, and the deionized water was replaced every 6 hours; after freeze-drying, bagasse carbon dots were obtained;
[0032] Step S2: 20 mL of the bagasse carbon dot solution (5 mg / mL) prepared in step S1 was taken, 0.2 g of sodium carbonate was added to adjust the pH to 9.0; 1.5 mg of hydroquinone and 0.71 g of glycidyl methacrylate (GMA) were added; the reaction was carried out at 45℃ for 12 hours in the dark; the reaction product was precipitated with anhydrous ethanol, centrifuged and washed 3 times, and then dispersed in 10 mL of deionized water for standby.
[0033] Step S3: 2.26 g of NIPAM, 1.04 g of 2-acrylamido-2-methylpropanesulfonic acid (AMPS) and 0.06 g of crosslinking agent MBA were dissolved in 30 mL of deionized water; add all the modified carbon dot dispersion prepared in step S2, and pass nitrogen for 40 minutes; 22 mg of ammonium persulfate and 15 μL of tetramethyl ethylenediamine were added; the polymerization reaction was initiated at 30℃ for 2 hours;
[0034] Step S4: To the system being reacted in step S3, 1.5 g of polyethylene glycol methyl ether methacrylate (MPEG-MA, Mn≈950) was added at a uniform speed; the reaction kettle was heated to 50℃, and the reaction was continued for 8 hours; the reaction liquid was heated to 70℃, and then filtered and washed with 70℃ hot water 3 times; finally, the product was redispersed in cold water and freeze-dried to obtain a carbon dot scale inhibitor.
[0035] Example 3
[0036] A scale inhibitor for a wet-process phosphoric acid production device, by weight, comprises: ammonium citrate 40 parts, sodium alkyl benzene sulfonate 2 parts, and carbon dot scale inhibitor 15 parts;
[0037] The preparation method of the carbon dot scale inhibitor comprises the following steps:
[0038] Step S1: Weigh 2.0g of sugarcane bagasse powder and disperse it in 60mL of deionized water. After stirring evenly, transfer it to a 100mL high-pressure reactor lined with polytetrafluoroethylene. Place the reactor in a constant temperature forced-air oven and pyrolyze it at 200℃ for 10 hours. After the reaction, allow it to cool naturally to room temperature. Centrifuge the resulting dark brown solution at 10,000r / min for 15 minutes and collect the supernatant. Filter the supernatant through a 0.22μm microporous membrane and dialyze it in a dialysis bag with a molecular weight cutoff of 1000Da for 48 hours, changing the deionized water every 6 hours. After freeze-drying, obtain sugarcane carbon dots.
[0039] Step S2: Take 20 mL of the sugarcane carbon dot solution (5 mg / mL) prepared in step S1, add 0.2 g sodium carbonate to adjust the pH to 9.0; add 1.5 mg hydroquinone and 0.71 g glycidyl methacrylate (GMA); react at 45 °C in the dark for 12 hours; precipitate the reaction product with anhydrous ethanol, centrifuge and wash 3 times, and redisperse it in 10 mL of deionized water for later use.
[0040] Step S3: Dissolve 2.26g NIPAM, 1.04g 2-acrylamido-2-methylpropanesulfonic acid (AMPS), and 0.06g crosslinking agent MBA in 30mL of deionized water; add all the modified carbon dot dispersion prepared in step S2, and purge with nitrogen for 40 minutes; add 22mg ammonium persulfate and 15μL tetramethylethylenediamine; initiate the polymerization reaction at 30℃ for 2 hours;
[0041] Step S4: Add 1.5g of polyethylene glycol methyl ether methacrylate (MPEG-MA, Mn≈950) dropwise to the system in the reaction process of step S3 at a uniform rate; heat the reactor to 50°C and continue the reaction for 8 hours; heat the reaction solution to 70°C, filter it while hot and wash it 3 times with 70°C hot water; finally, redisperse the product in cold water and freeze dry to obtain the carbon dot scale inhibitor.
[0042] Comparative Example 1
[0043] A scale inhibitor for a wet-process phosphoric acid production unit comprises, by weight: 40 parts ammonium citrate, 2 parts sodium alkylbenzene sulfonate, and 15 parts carbon point scale inhibitor.
[0044] The preparation method of the carbon point scale inhibitor includes the following steps:
[0045] Step S1: 2.0 g of sugarcane residue powder was dispersed in 60 mL of deionized water, stirred uniformly, and then transferred to a 100 mL polytetrafluoroethylene-lined high-pressure reaction kettle; the reaction kettle was placed in a constant-temperature air oven, and pyrolysis reaction was carried out at 200℃ for 10 hours; after the reaction was completed, it was naturally cooled to room temperature, the obtained dark brown solution was centrifuged at 10,000 r / min for 15 minutes, and the supernatant was taken; the supernatant was sequentially filtered through a 0.22 μm microporous filter membrane, and then placed in a dialysis bag with a molecular weight cut-off of 1000 Da for dialysis for 48 hours, and the deionized water was replaced every 6 hours; after freeze-drying, a carbon dot scale inhibitor was obtained.
[0046] Comparative Example 2
[0047] A scale inhibitor for a wet-process phosphoric acid production device, comprising, by weight: ammonium citrate 40 parts, sodium alkyl benzene sulfonate 2 parts, and carbon dot scale inhibitor 15 parts.
[0048] The preparation method of the carbon dot scale inhibitor comprises the following steps:
[0049] Step S1: 2.0 g of sugarcane residue powder was dispersed in 60 mL of deionized water, stirred uniformly, and then transferred to a 100 mL polytetrafluoroethylene-lined high-pressure reaction kettle; the reaction kettle was placed in a constant-temperature air oven, and pyrolysis reaction was carried out at 200℃ for 10 hours; after the reaction was completed, it was naturally cooled to room temperature, the obtained dark brown solution was centrifuged at 10,000 r / min for 15 minutes, and the supernatant was taken; the supernatant was sequentially filtered through a 0.22 μm microporous filter membrane, and then placed in a dialysis bag with a molecular weight cut-off of 1000 Da for dialysis for 48 hours, and the deionized water was replaced every 6 hours; after freeze-drying, a carbon dot scale inhibitor was obtained.
[0050] Step S2: 20 mL of the sugarcane carbon dot solution (5 mg / mL) prepared in step S1 was taken, 0.2 g of sodium carbonate was added to adjust the pH to 9.0; 1.5 mg of hydroquinone and 0.71 g of glycidyl methacrylate (GMA) were added; the reaction was carried out at 45℃ for 12 hours in the dark; the reaction product was precipitated with anhydrous ethanol, centrifuged and washed 3 times, and then freeze-dried to obtain a carbon dot scale inhibitor.
[0051] Comparative Example 3
[0052] A scale inhibitor for a wet-process phosphoric acid production device, comprising, by weight: ammonium citrate 40 parts, sodium alkyl benzene sulfonate 2 parts, and carbon dot scale inhibitor 15 parts.
[0053] The preparation method of the carbon dot scale inhibitor comprises the following steps:
[0054] Step S1: 2.0 g of bagasse powder was dispersed in 60 mL of deionized water, stirred uniformly, and then transferred to a 100 mL polytetrafluoroethylene-lined high-pressure reaction kettle; the reaction kettle was placed in a constant-temperature air oven, and pyrolysis was carried out at 200℃ for 10 hours; after the reaction was completed, it was naturally cooled to room temperature, and the obtained dark brown solution was centrifuged at 10,000 r / min for 15 minutes, and the supernatant was taken; the supernatant was filtered through a 0.22 μm microporous filter in turn, and was placed in a dialysis bag with a molecular weight cut-off of 1000 Da for dialysis for 48 hours, and the deionized water was replaced every 6 hours; after freeze-drying, bagasse carbon dots were obtained;
[0055] Step S2: 20 mL of the bagasse carbon dot solution (5 mg / mL) prepared in step S1 was taken, 0.2 g of sodium carbonate was added to adjust the pH to 9.0; 1.5 mg of hydroquinone and 0.71 g of glycidyl methacrylate (GMA) were added; the reaction was carried out at 45℃ for 12 hours in the dark; the reaction product was precipitated with anhydrous ethanol, centrifuged and washed 3 times, and then redispersed in 10 mL of deionized water for standby.
[0056] Step S3: 2.26 g of NIPAM, 1.04 g of 2-acrylamido-2-methylpropanesulfonic acid (AMPS), and 0.06 g of crosslinking agent MBA were dissolved in 30 mL of deionized water; all the modified carbon dot dispersion liquid prepared in step S2 was added, and nitrogen was blown for 40 minutes; 22 mg of ammonium persulfate and 15 μL of tetramethyl ethylenediamine were added; the polymerization reaction was initiated at 30℃ for 2 hours, and then freeze-dried to obtain carbon dot scale inhibitor.
[0057] Test Example 1
[0058] The coupon was washed with water and acetone, then sanded with 800# sandpaper, then dehydrated with anhydrous ethanol, and dried. The prepared simulated wet-process phosphoric acid mixed acid solution was poured into a beaker, heated to 70℃, mixed uniformly, and then the coupon was placed in it, and stood for 24 hours, then the coupon was taken out and dried in an 80℃ oven for 2h, weighed, and the amount of scale on the coupon was calculated, wherein the area of the coupon was 14 cm 2 . The addition amount of the scale inhibitor for the wet-process phosphoric acid production device was 0.025 (wt)%, and the preparation method was to mix ammonium citrate, sodium alkyl benzene sulfonate and carbon dot scale inhibitor uniformly.
[0059] The basic composition of the simulated wet-process phosphoric acid mixed acid solution is as follows.
[0060] Table 1 Composition of simulated wet-process phosphoric acid mixed acid solution
[0061] Component P2O5 H2SO4 Na2SiF6 K2SiF6 CaSO42H2O Content (wt%) 22 2.4 1.173 0.72 Saturation
[0062] The calculation formula of the scale inhibition rate is:
[0063]
[0064] wherein G1 is the fouling mass of the coupon without scale inhibitor, and G2 is the fouling mass of the coupon with scale inhibitor, in g. The test results are shown in Table 2.
[0065] Table 2 Performance Test Results
[0066] Antifouling rate Example 1 72% Example 2 85% Example 3 96% Comparative Example 1 28% Comparative Example 2 35% Comparative Example 3 42%
Claims
1. A scale inhibitor for a wet-process phosphoric acid production plant, characterized by comprising: The following components are included by weight parts: ammonium citrate: 40 parts; Sodium alkyl benzene sulfonate: 2 parts; Carbon dot scale inhibitor: 5-15 parts.
2. The scale inhibitor for a wet-process phosphoric acid production apparatus according to claim 1, characterized by The preparation method of the carbon dot scale inhibitor comprises the following steps: 1) Preparation of sugarcane carbon dots: weigh the sugarcane residue powder and disperse it in deionized water, and carry out pyrolysis reaction at 200℃ for 10 hours. After the reaction is completed, cool, centrifuge and take the supernatant, filter, and then put it into a dialysis bag with a molecular weight cut-off of 1000 Da for dialysis for 48 hours. Freeze-drying obtains the sugarcane carbon dots; 2) Vinyl modification: take the sugarcane carbon dot solution, add sodium carbonate to adjust the pH to 9.0, add hydroquinone polymerization inhibitor and glycidyl methacrylate, and react at 45℃ in the dark for 12 hours. The product is washed with anhydrous ethanol and then redispersed in water for use; 3) Core copolymerization: dissolve N-isopropyl acrylamide, 2-acrylamido-2-methylpropanesulfonic acid and crosslinking agent N,N'-methylene bisacrylamide in deionized water, and add the modified carbon dot dispersion prepared in step 2) and nitrogen to remove dissolved oxygen; 4) Initiation and grafting: add ammonium persulfate and tetramethyl ethylenediamine, and initiate polymerization reaction at 30℃ for 2 hours. Then, polyethylene glycol methyl ether methacrylate is added at a constant speed, and the temperature is raised to 50℃ for continuous reaction for 8 hours; 5) Purification: heat the reaction liquid to 70℃, filter while hot and wash with 70℃ hot water to remove free polyethylene glycol. After redispersion, freeze-drying obtains the carbon dot scale inhibitor.
3. The scale inhibitor for a wet-process phosphoric acid production apparatus according to claim 2, characterized by: In step 1), the ratio of the use amount of the sugarcane residue powder to deionized water is 2.0g:60mL.
4. The scale inhibitor for a wet-process phosphoric acid production apparatus according to claim 2, characterized by: In step 2), the amount of hydroquinone is 1.5mg, and the amount of glycidyl methacrylate is 0.71g.
5. The scale inhibitor for a wet-process phosphoric acid production apparatus according to claim 2, characterized by: In step 3), the amounts of each component are: N-isopropyl acrylamide 2.26g, 2-acrylamido-2-methylpropanesulfonic acid 1.04g, and N,N'-methylene bisacrylamide 0.06g.
6. A scale inhibitor for a wet-process phosphoric acid plant according to claim 2, characterized in that: In step 4), the molecular weight Mn of polyethylene glycol methyl ether methacrylate is about 950, and the dropwise addition amount is 1.5g.
7. A method for preparing the scale inhibitor for the wet-process phosphoric acid production apparatus according to claim 1, characterized by: Weigh each component in proportion, mix uniformly, and it is ready for use.
8. The use of a scale inhibitor for a wet-process phosphoric acid production device in claim 1 to inhibit calcium sulfate scale and fluorosilicate scale in the wet-process phosphoric acid concentration process.