CN114316632A - Preparation method of polymer-coated phosphogypsum composite master batch - Google Patents

Abstract

The invention provides a preparation method of polymer-coated phosphogypsum composite masterbatch, which relates to the technical fields of hydrophobic modification of inorganic fillers and composite material preparation. The method comprises the following steps: using phosphogypsum waste residue as raw material, calcining in a gradient furnace, grinding and sieving to obtain anhydrous phosphogypsum, and treating the anhydrous phosphogypsum with sodium hydroxide and anhydrous sodium sulfate to obtain hydroxylated phosphorus gypsum Gypsum, surface modification of hydroxylated phosphogypsum with modifier to obtain modified phosphogypsum, hydrophobic polymer-coated phosphogypsum composite obtained by in-situ suspension polymerization of modified phosphogypsum, vinyl monomers and reaction assistants masterbatch. Polymer-coated phosphogypsum composite masterbatch can be used as filler in polymer materials such as plastic or rubber, which can significantly enhance the molecular entanglement and interface between phosphogypsum and polymer matrix, and significantly improve the comprehensive performance of polymer composite materials. . At the same time, the invention has great significance for the resource utilization of phosphogypsum, and can broaden the application range of phosphogypsum.

Description

A kind of preparation method of polymer-coated phosphogypsum composite masterbatch

technical field

The invention relates to the technical field of inorganic filler modification and composite material preparation, in particular to a preparation method of polymer-coated phosphogypsum composite masterbatch.

Background technique

Phosphogypsum is the main solid waste residue produced in the phosphoric acid wet process. For every 1t of phosphoric _acid produced, about 5t of phosphogypsum slag will be produced as a by _- product. Impurities such as phosphoric acid, organic matter, acid insoluble matter. The comprehensive utilization rate of phosphogypsum is low. The annual output of phosphogypsum in China is 70 million tons, and the comprehensive utilization rate is about 40%. As a result, the storage of phosphogypsum has caused huge pressure on the ecological environment. Every 10,000 tons of phosphogypsum accumulated in the open air occupies about ^4,000m2 of land, and after weathering over time, it is easy to cause dusty weather, pollute the atmosphere, and affect people's breathing health. Among them, soluble phosphorus, fluorine, and organic matter are immersed under the scouring of rainwater. Soil and groundwater have seriously restricted the sustainable strategy of China's phosphorus chemical industry. Therefore, it is urgent to improve the comprehensive utilization rate of phosphogypsum.

Phosphogypsum crystals are mostly flake-like, with a small amount of fibrous and spherical crystals. When used in plastic products, it can improve the stability, rigidity and hardness of materials, so it can replace some light calcium carbonate and heavy carbonic acid. Calcium is used as a filler for polymer materials such as plastic or rubber. However, the interfacial properties of phosphogypsum and polymers are very different. They are directly blended and easily agglomerated with each other. They are not uniformly dispersed in the matrix of the polymer material, and the material is easy to peel off and agglomerate from the matrix during the stress process. Therefore, pretreatment and surface modification of phosphogypsum are required. Usually, coupling agents such as silane, phthalate, and stearic acid are used to react with hydroxyl groups on the surface of inorganic particles for modification, but the molecular chains of these modifiers are short and cannot penetrate into the polymer matrix, and the coating layer is thin. The mechanical properties of polymer materials are limited.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a method for preparing polymer-coated phosphogypsum composite masterbatch, so as to solve the problems raised in the above-mentioned background technology.

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

A method for preparing a polymer-coated phosphogypsum composite masterbatch, comprising the following steps:

Step (1) put the phosphogypsum waste residue into a gradient furnace for calcination, then grind and sieve to obtain anhydrous phosphogypsum, and treat the anhydrous phosphogypsum with sodium hydroxide and anhydrous sodium sulfate to obtain hydroxylated phosphogypsum;

Step (2) Under a nitrogen atmosphere, the hydroxylated phosphogypsum, modifier, and ethanol aqueous solution are stirred at 30-70° C., and mixed to obtain a mixed solution, which is filtered, washed and dried in sequence to obtain modified phosphogypsum ;

Step (3) Under nitrogen atmosphere, disperse the mixture of modified phosphogypsum, deionized water, dispersant, vinyl monomer and initiator for 30-60min, and heat up to 50-75°C for suspension polymerization to obtain a reaction mixture , followed by filtration, washing and drying to obtain a hydrophobic polymer-coated phosphogypsum composite masterbatch.

As a further technical solution of the present invention, the phosphogypsum is the solid waste residue of the phosphoric acid wet process.

As a further technical solution of the present invention, the calcination temperature of the phosphogypsum is 450-800° C., and the calcination time is 0.5-3 h.

As a further technical solution of the present invention, the modifier is preferably one of titanate, stearic acid, calcium stearate, sodium oleate, aluminate, and silane coupling agent.

As a further technical solution of the present invention, the mass ratio of the hydroxylated phosphogypsum to the modifier ranges from 9:1 to 40:1.

As a further technical solution of the present invention, the dispersant is one or more of hydroxypropyl methylcellulose, methylcellulose, polyvinyl alcohol, and polyvinylpyrrolidone.

As a further technical solution of the present invention, the vinyl monomer is one or more of methyl methacrylate, ethyl methacrylate, isobornyl methacrylate, methyl acrylate, and styrene.

As a further technical solution of the present invention, the initiator is an organic peroxide or an azo compound, preferably dibenzoyl peroxide, dodecanoyl peroxide, diddecanoic acid peroxide, tert-butyl peracetate , one of tert-butyl perlaurate or azobisisobutyronitrile and 2,2'-bisazo-(2,4-dimethylvaleronitrile).

As a further technical solution of the present invention, the mass ratio of the vinyl monomer to the modified phosphogypsum ranges from 2.5:1 to 25:1; the mass ratio of the vinyl monomer to the initiator ranges from 30: 1 to 100:1; the mass ratio of the vinyl monomer to the dispersant ranges from 30:1 to 75:1.

A filler of polymer material, which adopts the above-mentioned polymer to coat phosphogypsum composite master batch.

Compared with the prior art, the present invention has the beneficial effects that: the present invention selects phosphogypsum solid waste as raw material, and after pretreatment to obtain anhydrous phosphogypsum, first carries out hydroxylation treatment on the anhydrous phosphogypsum to improve the surface quality of phosphogypsum. The number of hydroxyl groups, and then modified by modifiers, is polymerized with vinyl monomers in situ to prepare long-chain polymer-coated phosphogypsum composite masterbatches, which can be used as fillers for polymer materials and can significantly improve the performance of phosphogypsum in polymers. The dispersibility in the matrix enhances the interface effect and compatibility between the phosphogypsum and the polymer matrix, thereby significantly improving the comprehensive performance of the polymer composite material. At the same time, the invention has great significance for the resource utilization of phosphogypsum, and can broaden the application range of phosphogypsum.

Description of drawings

Fig. 1 is the composite master batch product diagram of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Embodiment 1:

A preparation method of polymer-coated phosphogypsum composite masterbatch, comprising the following steps:

S1. Put the phosphogypsum waste residue into a gradient furnace, calcine it at 600° C. for 2 hours, put it into a ball mill for ball milling, the ball mill rotates at 500 rpm, ball mill for 60 min, and sieve to obtain anhydrous phosphogypsum. Under a nitrogen atmosphere, anhydrous phosphogypsum is stirred and mixed with an aqueous solution of sodium hydroxide and sodium sulfate to obtain a mixed solution, which is sequentially filtered, washed and dried to obtain hydroxylated phosphogypsum.

S2. 2.0 g of neoalkoxy tris (dioctyl pyrophosphate acyloxy) titanate (TCA-L38) and 7.5 mL of deionized water were added to 150 mL of absolute ethanol for ultrasonic treatment for 8 min to obtain a mixture, The mixture was placed in a four-necked flask with a condensing reflux device, a thermometer, a stirrer, and a nitrogen-passing device, nitrogen was introduced, and the mixture was stirred at a speed of 300 rpm. , and the mixture was obtained after the reaction was incubated for 3 h. The above mixed solution is filtered, the solid matter is taken, and the solid matter is washed several times with ethanol, and then dried to obtain TCA-L38 modified phosphogypsum.

S3, adding 0.65 g of dodecanoyl peroxide and 8 g of the above-mentioned TCA-L38 modified phosphogypsum to 40 g of methyl methacrylate solution for ultrasonic treatment for 5 min to obtain an oil phase. An aqueous phase was obtained by adding 0.6 g of hydroxypropyl methylcellulose to 160 g of deionized water. The oil phase and the water phase were placed in a four-necked flask with a condensing reflux device, a thermometer, a stirrer, and a nitrogen-passing device, nitrogen was introduced, and stirred at a speed of 400 rpm. After 6 hours, the reaction mixture was obtained, filtered, and the solid was collected, washed with ethanol and deionized water for several times, and then dried to obtain a polymer-coated phosphogypsum composite masterbatch.

Embodiment 2:

A preparation method of polymer-coated phosphogypsum composite masterbatch, comprising the following steps:

S1. Put the phosphogypsum waste residue into a gradient furnace, calcinate at 550° C. for 3 hours, put it into a ball mill for ball milling, and the ball mill rotates at 500 rpm for 60 minutes, and sieve to obtain anhydrous phosphogypsum. Under a nitrogen atmosphere, anhydrous phosphogypsum is stirred and mixed with an aqueous solution of sodium hydroxide and sodium sulfate to obtain a mixed solution, which is sequentially filtered, washed and dried to obtain hydroxylated phosphogypsum.

S2, add 3.0g TCA-L38 and 7.5mL deionized water to 150mL absolute ethanol and carry out ultrasonic treatment for 8min to obtain a mixture, and place the mixture in a condensing reflux device, a thermometer, a stirrer, and a nitrogen-passing device. In the four-necked flask, nitrogen was introduced, and the mixture was stirred at a speed of 400 rpm. After the temperature was raised to 50° C., 30 g of the above-mentioned hydroxylated phosphogypsum was added, and the reaction was maintained for 4 hours to obtain a mixed solution. The above mixed solution is filtered, the solid matter is taken, and the solid matter is washed several times with ethanol, and then dried to obtain TCA-L38 modified phosphogypsum.

S3, adding 0.9 g of azobisisobutyronitrile and 8 g of the above-mentioned TCA-L38 modified phosphogypsum to 50 g of styrene solution for ultrasonic treatment for 5 min to obtain an oil phase. 0.35 g of hydroxypropyl methylcellulose and 0.35 g of methyl cellulose were added to 220 g of deionized water to obtain an aqueous phase. The oil phase and the water phase were placed in a four-necked flask with a condensing reflux device, a thermometer, a stirrer, and a nitrogen-passing device, and nitrogen was introduced, while stirring at a speed of 420 rpm, dispersing for 30 min, warming up to 65 ° C, and maintaining the temperature. After reacting for 8 hours, a reaction mixture was obtained, filtered, and the solid was collected, washed with ethanol and deionized water for several times, and then dried to obtain a polymer-coated phosphogypsum composite masterbatch.

Embodiment 3:

A preparation method of polymer-coated phosphogypsum composite masterbatch, comprising the following steps:

S1. Put the phosphogypsum waste residue into a gradient furnace, calcine it at 600° C. for 2 hours, put it into a ball mill for ball milling, the ball mill rotates at 500 rpm, ball mill for 60 min, and sieve to obtain anhydrous phosphogypsum. Under a nitrogen atmosphere, anhydrous phosphogypsum is stirred and mixed with an aqueous solution of sodium hydroxide and sodium sulfate to obtain a mixed solution, which is sequentially filtered, washed and dried to obtain hydroxylated phosphogypsum.

S2. Add 2.5 g of TCA-L38 and 7.5 mL of deionized water to 200 mL of absolute ethanol for 8 min of ultrasonic treatment to obtain a mixture. The mixture was placed in a four-necked flask with a condensing reflux device, a thermometer, a stirrer, and a nitrogen-passing device, and nitrogen was introduced, and stirred at a speed of 320 rpm. , and the mixture was obtained after the reaction was incubated for 3 h. The above mixed solution is filtered, the solid matter is taken, and the solid matter is washed several times with ethanol, and then dried to obtain TCA-L38 modified phosphogypsum.

S3, adding 0.8 g of dodecanoyl peroxide and 6 g of the above-mentioned TCA-L38 modified phosphogypsum to the mixed solution of 25 g of methyl methacrylate and 15 g of methyl acrylate for ultrasonic treatment for 5 min to obtain an oil phase. An aqueous phase was obtained by adding 0.6 g of hydroxypropyl methylcellulose to 180 g of deionized water. The oil phase and the water phase were placed in a four-necked flask with a condensing reflux device, a thermometer, a stirrer, and a nitrogen-passing device, and nitrogen was introduced, while stirring at a speed of 450 rpm, dispersed for 30 min, and heated to 70 ° C. After holding the reaction for 6 hours, the reaction mixture was obtained, filtered, and the solid was collected, washed with ethanol and deionized water for several times, and then dried to obtain a polymer-coated phosphogypsum composite masterbatch.

Embodiment 4:

A preparation method of polymer-coated phosphogypsum composite masterbatch, comprising the following steps:

S1. Put the phosphogypsum waste residue into a ball mill for ball milling. The ball mill rotates at 500 rpm for 60 min, and then put it into a gradient furnace, calcined at 650° C. for 1.5 h, and sieved to obtain anhydrous phosphogypsum. Under a nitrogen atmosphere, anhydrous phosphogypsum is stirred and mixed with an aqueous solution of sodium hydroxide and sodium sulfate to obtain a mixed solution, which is sequentially filtered, washed and dried to obtain hydroxylated phosphogypsum.

S2, 2.0g stearic acid is added in 180mL absolute ethanol and carries out ultrasonic treatment after 8min, obtain mixture, and mixture is placed in the four-necked flask with condensation reflux device, thermometer, stirrer, logical nitrogen device, pass through Nitrogen was introduced, stirred at a speed of 300 rpm, heated to 60° C., and then 30 g of the above-mentioned hydroxylated phosphogypsum was added, and the mixture was obtained after the reaction was maintained for 3 hours. The mixed solution is filtered, the solid matter is taken, and the solid matter is washed with ethanol for several times, and then dried to obtain stearic acid-modified phosphogypsum.

S3, adding 0.6 g of dibenzoyl peroxide and 7 g of the above-mentioned stearic acid-modified phosphogypsum to 45 g of methyl methacrylate solution for ultrasonic treatment for 5 min to obtain an oil phase. 0.9 g of polyvinyl alcohol was added to 170 g of deionized water to obtain an aqueous phase. The oil phase and the water phase were placed in a four-necked flask with a condensing reflux device, a thermometer, a stirrer, and a nitrogen-passing device, and nitrogen was introduced, while stirring at a speed of 415 rpm, dispersed for 50 min, heated to 70 ° C, and kept warm. After reacting for 6 hours, a reaction mixture was obtained, filtered, and the solid was collected, washed with ethanol and deionized water for several times, and then dried to obtain a polymer-coated phosphogypsum composite masterbatch.

Embodiment 5:

A method for preparing a polymer-coated phosphogypsum composite masterbatch, comprising the following steps:

S1. Put the phosphogypsum waste residue into a ball mill for ball milling. The ball mill rotates at 500 rpm for 50 min, and then put it into a gradient furnace and calcined at 800° C. for 0.5 h to obtain anhydrous phosphogypsum. Under a nitrogen atmosphere, phosphogypsum is stirred and mixed with an aqueous solution of sodium hydroxide and sodium sulfate to obtain a mixed solution, which is sequentially filtered, washed and dried to obtain hydroxylated phosphogypsum.

S2, 2.5g stearic acid is added in 200mL absolute ethanol and carries out ultrasonic treatment after 8min, obtains mixture, and mixture is placed in the four-necked flask with condensation reflux device, thermometer, stirrer, and nitrogen-passing device, pass through Enter nitrogen, stir at a speed of 350 rpm, and at the same time raise the temperature to 60° C., add 30 g of the above-mentioned hydroxylated phosphogypsum, and keep the reaction for 3 hours to obtain a mixed solution. The above mixed solution is filtered, and the solid matter is collected, washed with ethanol for several times, and then dried to obtain stearic acid-modified phosphogypsum.

S3, adding 0.6 g of dodecanoyl peroxide and 8 g of the above-mentioned stearic acid-modified phosphogypsum to the mixed solution of 40 g of methyl methacrylate and 10 g of isobornyl methacrylate for ultrasonic treatment for 5 min to obtain an oil phase. 1 g of polyvinyl alcohol was added to 200 g of deionized water to obtain an aqueous phase. The oil phase and the water phase were placed in a four-necked flask with a condensing reflux device, a thermometer, a stirrer, and a nitrogen-passing device, and nitrogen was introduced, while stirring at a speed of 450 rpm, dispersed for 30 min, heated to 70 ° C, and kept warm. After reacting for 6 hours, a reaction mixture was obtained, filtered, and the solid was collected, washed with ethanol and deionized water for several times, and then dried to obtain a polymer-coated phosphogypsum composite masterbatch.

It will be apparent to those skilled in the art that the present invention is not limited to the details of the above-described exemplary embodiments, but that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments are to be regarded in all respects as illustrative and not restrictive, and the scope of the invention is to be defined by the appended claims rather than the foregoing description, which are therefore intended to fall within the scope of the claims. All changes within the meaning and scope of the equivalents of , are included in the present invention. Any reference signs in the claims shall not be construed as limiting the involved claim.

In addition, it should be understood that although this specification is described in terms of embodiments, not each embodiment only includes an independent technical solution, and this description in the specification is only for the sake of clarity, and those skilled in the art should take the specification as a whole , the technical solutions in each embodiment can also be appropriately combined to form other implementations that can be understood by those skilled in the art.

Claims (10)

1. The preparation method of the polymer-coated phosphogypsum composite master batch is characterized by comprising the following steps:

putting the phosphogypsum waste residue into a gradient furnace for calcination, then grinding and screening to obtain anhydrous phosphogypsum, and treating the anhydrous phosphogypsum by using sodium hydroxide and anhydrous sodium sulfate to obtain hydroxylated phosphogypsum;

stirring the hydroxylated phosphogypsum, the modifier and the ethanol aqueous solution at 30-70 ℃ in a nitrogen atmosphere, mixing to obtain a mixed solution, and sequentially filtering, washing and drying to obtain the modified phosphogypsum;

and (3) dispersing the mixture of the modified phosphogypsum, deionized water, a dispersing agent, a vinyl monomer and an initiator for 30-60min in a nitrogen atmosphere, heating to 50-75 ℃ for suspension polymerization reaction to obtain a reaction mixture, and sequentially filtering, washing and drying to obtain the hydrophobic polymer-coated phosphogypsum composite master batch.

2. The preparation method of the polymer-coated phosphogypsum composite masterbatch according to claim 1, wherein the phosphogypsum is solid waste residue in a phosphoric acid wet process.

3. The preparation method of the polymer-coated phosphogypsum composite master batch according to claim 1, which is characterized in that the calcination temperature of the phosphogypsum is 450-800 ℃, and the calcination time is 0.5-3 h.

4. The preparation method of the polymer-coated phosphogypsum composite master batch according to claim 1, wherein the modifier is preferably one of titanate, stearic acid, calcium stearate, sodium oleate, aluminate ester and silane coupling agent.

5. The preparation method of the polymer-coated phosphogypsum composite masterbatch according to claim 1, wherein the mass ratio of the hydroxylated phosphogypsum to the modifier is in the range of 9: 1 to 40: 1.

6. the preparation method of the polymer-coated phosphogypsum composite master batch according to claim 1, wherein the dispersing agent is one or more of hydroxypropyl methylcellulose, polyvinyl alcohol and polyvinylpyrrolidone.

7. The preparation method of the polymer-coated phosphogypsum composite masterbatch according to claim 1, wherein the vinyl monomer is one or more of methyl methacrylate, ethyl methacrylate, isobornyl methacrylate, methyl acrylate and styrene.

8. The method for preparing the polymer-coated phosphogypsum composite masterbatch according to claim 1, wherein the initiator is an organic peroxide or an azo compound, preferably one of dibenzoyl peroxide, lauroyl peroxide, didecanoic acid peroxide, tert-butyl peracetate, tert-butyl peraurate or azobisisobutyronitrile and 2, 2' -bisazo- (2, 4-dimethyl valeronitrile).

9. The preparation method of the polymer-coated phosphogypsum composite masterbatch according to claim 1, wherein the mass ratio of the vinyl monomer to the modified phosphogypsum is within the range of 2.5: 1 to 25: 1; the mass ratio of the vinyl monomer to the initiator is in the range of 30: 1 to 100: 1; the mass ratio of the vinyl monomer to the dispersant ranges from 30: 1 to 75: 1.

10. a filler of high molecular material, characterized in that the polymer according to any one of claims 1-9 is used to coat the phosphogypsum composite masterbatch.

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