KR20230166632A - Method for recovering of high purity mma from waste artificial marble - Google Patents

Abstract

The present invention relates to a method for recovering high purity MMA from waste artificial marble, and involves extracting crushed waste artificial marble with a solvent to separate solid inorganic substances and obtaining a liquid extract containing acrylic resin (S10). ) and a PMMA acquisition step (S20) in which PMMA is obtained by reacting the liquid extract obtained in the liquid phase separation step (S10) with a tetrahydrofuran solvent, and the PMMA obtained in the PMMA acquisition step (S20) is subjected to a vacuum depolymerization reaction. A regenerated MMA obtaining step (S30) of purifying and obtaining regenerated MMA, and a polymer self-processing aid manufacturing step (S40) of producing an acrylic polymer processing aid by performing an emulsion polymerization reaction on the regenerated MMA obtained in the regenerated MMA obtaining step (S30). It is characterized by being able to separate high-purity MMA and recycle it for the manufacture of polymer processing aids.

Description

Method for recovering high purity MMA from waste artificial marble {METHOD FOR RECOVERING OF HIGH PURITY MMA FROM WASTE ARTIFICIAL MARBLE}

The present invention relates to a method for recovering high-purity MMA from waste artificial marble, and more specifically, to separate high-purity MMA from components contained in waste artificial marble generated in the manufacturing process of artificial marble and recycle it for the production of polymer processing aids. It's about how to do it.

In general, artificial marble is manufactured by using natural ore powder or synthetic inorganic material powder as a filler, hardening it with resin, and then using a compression press. Since a dense structure with inorganic pores is obtained through pressure molding, it is widely used to form color shades and shapes that cannot be found in natural marble.

Materials used as fillers in the manufacturing process of artificial marble include aluminum hydroxide, barium sulfate, barium carbonate, calcium carbonate, silica (silica sand), granite, and stone dust. Resin materials include thermosetting unsaturated polyester and Thermoplastic methyl methacrylic resin (hereinafter MMA) is used.

Briefly looking at the manufacturing process of artificial marble, it includes the steps of mixing raw materials such as aluminum oxide, methyl methacrylate, crosslinking agent, initiator, and colorant; heating and pressurizing the mixed raw materials to compress them into the desired size and shape; It consists of a cutting stage according to the size standard for each product, a sanding stage to polish the surface, and a processing stage to create an appearance according to the customer's specifications. A large amount of waste is generated during each stage.

For example, in the process of cleaning the inside of the reactor with MMA raw materials when replacing products in the mixing stage, MMA in the form of a sludge or solution containing MMA is generated, and the entire amount of the sludge is disposed of.

In addition, marble that has various defects in the compression stage or is cut during cutting is manufactured into particles of a certain size through crushing and pulverization and is partially reused as pattern beads, but most of the unused portion or semi-shaped and fine particles are discarded. Waste generated in the form of wet sludge and dry fine powder during sanding and brushing for surface gloss, as well as waste generated in the form of stick-shaped pieces during the processing of the appearance of each product, are all being disposed of. am.

Due to the problem of disposing of artificial marble waste, attempts have recently been made to develop various technologies to effectively dispose of waste artificial marble.

As an example, Korean Patent No. 10-0891378 describes a process of crushing scraps of artificial marble made of MMA and aluminum hydroxide through a crusher, and sending the crushed material and artificial marble dust into a pyrolysis furnace heated by electricity by a screw feeder. A horizontal transfer pyrolysis process that pyrolyzes by supplying a fixed amount, and an MMA recovery process in which the gas components generated in the horizontal transfer pyrolysis process are supplied, condensed in a condenser, liquefied, and separated with a centrifuge and an oil-water separator to receive MMA components with water and impurities removed. MMA and alumina from waste artificial marble, including a calcination process of completely burning and removing organic substances by heating the residues of the horizontal transfer pyrolysis process in a calcination furnace, and an alumina recovery process of collecting the alumina, which is the residue of the predetermined process, by cooling it with a cooler. Configure the recovery method.

As another example, Korean Patent No. 10-1466011 discloses the steps of recovering acrylic resin and amorphous pseudo-boehmite from waste artificial marble using aerobic low-temperature pyrolysis, and dissolving the amorphous pseudo-boehmite in caustic soda. Preparing a sodium aluminate solution, removing impurities from the sodium aluminate solution and then precipitating it to produce white-colored aluminum hydroxide, and calcining the white-colored aluminum hydroxide at a high temperature to obtain high-purity alumina. A method for producing acrylic resin and alumina from waste artificial marble is provided.

Korean Patent No. 10 - 0891378 (2009.04.02) Korean Patent No. 10 - 1466011 (2014.11.27) Korea Public Utility Model No. 20 - 2015 - 0003122 (2015.08.19) Korean Patent Publication No. 10 - 2008 - 0078241 (2008.08.27)

The method of recovering MMA from waste artificial marble using the above-described prior art involves recovering acrylic resin through thermal decomposition technology and heat-treating the residue to produce alumina.

However, since the thermal decomposition technology of waste artificial marble according to the prior art is performed without the introduction of air, recovery of MMA is possible only when the pyrolysis temperature is maintained above 500°C. In the process of thermal decomposition of waste artificial marble above 500°C, gas is released. There is a problem that flames occur inside the kiln due to ignition and loss of the acrylic resin to be recovered occurs.

In addition, when thermal decomposition proceeds above 500℃, the thermal decomposition of aluminum hydroxide used as a mixture filler progresses rapidly, causing a phase transition from gibbsite to gamma-alumina (γ-Al2O3), which ultimately significantly reduces the yield. There is a problem that acts as a factor.

In particular, PMMA and MMA recovered from waste artificial marble by thermal decomposition method according to the prior art contain a significant amount of impurities, so a separate purification process is inevitable in order to be reused as a high-purity raw material, and there are limits to the commercialization of the process itself. This is the situation.

In addition, in another example of a method of producing acrylic resin and alumina from waste artificial marble using aerobic low-temperature pyrolysis according to the prior art, aerobic low-temperature pyrolysis capable of pyrolysis at 350 to 450°C is achieved by injecting an appropriate amount of air into the continuous rotary kiln section. It is configured to recover acrylic resin and amorphous pseudo-boehmite from waste artificial marble.

However, the above-described prior art also does not provide a way to fundamentally solve the problem of a large amount of impurities existing in PMMA and MMA recovered from waste artificial marble, and excessive energy costs are incurred as high temperatures are maintained in the rotary kiln for pyrolysis. There is a problem with consumption.

Accordingly, the present invention was invented to solve the problems of the prior art as described above.

A liquid phase separation step (S10) of extracting the pulverized waste artificial marble with a solvent to separate solid inorganic substances and obtain a liquid extract containing acrylic resin;

A PMMA obtaining step (S20) in which PMMA is obtained by reacting the liquid extract obtained in the liquid phase separation step (S10) with a tetrahydrofuran solvent,

It includes a regenerated MMA obtaining step (S30) of purifying the PMMA obtained in the PMMA obtaining step (S20) by vacuum depolymerization to obtain regenerated MMA,

By further comprising a polymer self-processing aid manufacturing step (S40) of producing an acrylic polymer processing aid by emulsion polymerizing the recycled MMA obtained in the recycled MMA obtaining step (S30), high purity MMA is separated and used for the production of a polymer processing aid. It is possible to achieve the purpose of recycling.

The present invention provides a method for separating high-purity MMA from components contained in waste artificial marble generated in the manufacturing process of artificial marble and recycling it for the production of polymer processing aids.

In particular, the present invention has the advantage of overcoming the problems of lower purity and yield due to side reactions, which are problems that occur in the existing high-temperature heat treatment process, because the treatment is performed at a very low temperature compared to the prior art.

In addition, the present invention has the effect of significantly saving energy and contributing to improved productivity by pyrolyzing only the acrylic resin recovered through solvent extraction at low temperature compared to the conventional method of pyrolyzing 100% of the entire waste artificial marble by weight at high temperature.

In addition, the present invention can produce polymer processing aids or acrylic resins through emulsion polymerization of recovered high-purity acrylic monomer (MMA), so it not only has the effect of replacing the existing import of polymer processing aids, but also creates a technology-intensive high value-added industry. There is an effect that can be created.

Figures 1 and 2 are process flow diagrams of a method for recovering high purity MMA from waste artificial marble according to the present invention.
Figure 3 is a schematic process diagram of the PMMA acquisition step to the recycled MMA acquisition step of the method for recovering high purity MMA from waste artificial marble according to the present invention.
Figure 4 is a schematic process diagram of the polymer self-processing manufacturing step of the method for recovering high purity MMA from waste artificial marble according to the present invention.
Figure 5 is a molecular weight test graph of a polymer processing aid by the method for recovering high purity MMA from waste artificial marble according to the present invention.

Hereinafter, the structure and operation of a preferred embodiment of the method for recovering high purity MMA from waste artificial marble of the present invention will be described in detail with reference to the accompanying drawings. In the following description, detailed descriptions of parts that can be easily implemented by those skilled in the art may be omitted. In addition, since the following description describes the present invention with preferred embodiments, the present invention is not limited by the following examples, and it is natural that various modifications may be made without departing from the scope of the present invention. will be.

Figures 1 and 2 are process flow charts of the method for recovering high-purity MMA from waste artificial marble according to the present invention, and Figure 3 is a PMMA obtaining step to the recycled MMA obtaining step of the method for recovering high-purity MMA from waste artificial marble according to the present invention. Figure 4 is a schematic process diagram of the polymer self-processing agent manufacturing step of the method for recovering high-purity MMA from waste artificial marble according to the present invention, and Figure 5 is a schematic process diagram of recovering high-purity MMA from waste artificial marble according to the present invention. This shows a graph of the molecular weight test of the polymer processing aid by the following method.

The method of recovering high-purity MMA from waste artificial marble to which the technology of the present invention is applied is a technology that separates high-purity MMA from components contained in waste artificial marble generated in the manufacturing process of artificial marble and recycles it for the production of polymer processing aids. Please note that it is about.

For this purpose, the method of recovering high purity MMA from waste artificial marble of the present invention largely includes a liquid phase separation step (S10), a PMMA acquisition step (S20), a recycled MMA acquisition step (S30), and a polymer self-processing preparation step (S40). It includes, and specifically, is as follows.

The liquid phase separation step (S10) is a step of extracting the pulverized waste artificial marble with a solvent to separate solid inorganic substances and obtain a liquid extract containing acrylic resin.

The PMMA obtaining step (S20) is a step of obtaining PMMA by reacting the liquid extract obtained in the liquid phase separation step (S10) with a tetrahydrofuran (THF) solvent.

THF used in the PMMA obtaining step (S20) is a saturated pentagonal heterocyclic organic compound (C ₄ H ₈ O) containing one oxygen, which is miscible with water and is used as an aprotic polar solvent during organic chemical reactions. It has a boiling point of 66°C and is used as a solvent to recover acrylic resin contained in waste artificial marble.

The PMMA acquisition step (S20) consists of a first dissolution step (S21), a second dissolution step (S22), and a PMMA recovery step (S23).

In the first dissolution step (S21), the acrylic resin is recovered by first reacting the liquid extract obtained in the liquid phase separation step (S10) with a tetrahydrofuran solvent.

In the first dissolution step (S21), the THF and the liquid extract are reacted to precipitate and separate aluminum hydroxide, an inorganic species with a specific gravity higher than THF, and recover the acrylic resin from the supernatant.

The secondary dissolution step (S22) is a step of dissolving low molecular weight organic compounds and recovering the undissolved acrylic resin by secondary reaction of tetrahydrofuran solvent to the acrylic resin recovered in the first dissolution step (S21).

In the second dissolution step (S22), low-molecular organic chemical species such as colorants contained in the waste artificial marble are dissolved to remove impurities.

In the first dissolution step (S21) and the second dissolution step (S22), the reaction temperature is raised to 66°C, which is the boiling point of the tetrahydrofuran solvent, and the solvent and acrylic resin that evaporate and condense to the top of the reactor are recovered. In the first dissolution step (S21) and the second dissolution step (S22), the evaporated THF gas is condensed using a reflux cooling device and returned to the reactor to maximize extraction efficiency.

The PMMA recovery step (S23) is a step of fractionating the acrylic resin recovered in the secondary dissolution step (S22) to separate impurities and recover PMMA.

In the PMMA recovery step (S23), distilled water, CaCl, and NaCl are added to the acrylic resin and subjected to fractional distillation at a temperature of 60 to 65° C. to phase separate water and aluminum hydroxide, the solvent, and PMMA, and recover PMMA. Since THF tends to partially dissolve in water during the phase separation process, a small amount of CaCl and NaCl are added to increase the polarity of water to prevent dissolution of THF.

The regenerated MMA obtaining step (S30) is a step of purifying the PMMA obtained in the PMMA obtaining step (S20) by vacuum depolymerization to obtain regenerated MMA.

In the recycled MMA acquisition step (S30), the acrylic resin recovered in the PMMA acquisition step (S20) is pyrolyzed through vacuum depolymerization while maintaining a vacuum state to remove heterogeneous chemical species and to use it as a raw material monomer for a polymer processing aid. This is done to obtain high purity regenerated MMA, which is an acrylic monomer of a suitable purity of at least 97%.

The regenerated MMA acquisition step (S30) includes an MMA gas recovery step (S31), a condensed MMA recovery step (S32), and an MMA recovery step (S33).

The MMA gas recovery step (S31) is a step of recovering gaseous MMA by vacuum depolymerizing the PMMA obtained in the PMMA obtaining step (S20).

In the MMA gas recovery step (S31), PMMA is introduced into a vacuum chamber and decomposed at a temperature of 200 to 250°C in a vacuum of 0.1 Torr or less to recover gaseous MMA.

In the MMA gas recovery step (S31), the decomposition reaction proceeds under vacuum low-temperature depolymerization conditions, so that the thermal decomposition of aluminum hydroxide, which was previously used as a mixture filler for artificial marble during high-temperature pyrolysis above 500°C, progresses rapidly and gibbsite is formed. It is designed to eliminate the problem of significantly reducing the yield of acrylic resin due to phase transition to gamma-alumina (γ-Al2O3).

The condensed MMA recovery step (S32) is a step of recovering condensed MMA by heating and distilling the gaseous MMA recovered in the MMA gas recovery step (S31).

In the condensed MMA recovery step (S32), condensed MMA distilled together with water is recovered by heating at a temperature of 101° C., which is the boiling point of MMA, in a distillation device.

The MMA recovery step (S33) is a step of fractionating the condensed MMA recovered in the condensed MMA recovery step (S32) to separate the water layers and recovering the purified recycled MMA.

In the MMA recovery step (S33), the condensed MMA is fractionally distilled at a temperature of 95 to 100° C. to separate water and MMA, and the purified recycled MMA is recovered in the upper layer.

The regenerated MMA obtained in the regenerated MMA obtaining step (S30) further includes a polymer self-processing aid manufacturing step (S40) of producing an acrylic polymer processing aid by an emulsion polymerization reaction.

In the polymer processing aid manufacturing step (S40), acrylic polymer processing aid powder used in various building materials such as flooring, windows, and landscaping is manufactured using recycled MMA with a purity of 97% or higher obtained in the recycled MMA acquisition step (S30). do.

The polymer self-processing preparation step (S40) includes an emulsion composition step (S41), an emulsion polymerization step (S42), an aggregation step (S43), and a powdering step (S44).

The emulsion composition step (S41) is a step of forming an emulsion by adding water and regenerated MMA to the reactor at a weight ratio of 1:1 to 5, adding an emulsifier, and stirring.

In the emulsion composition step (S41), water and regenerated MMA are mixed and 0.5 to 5 parts by weight of a lipophilic emulsifier such as OLEIC, STEARIC, FATTY, LAURYL, and RESIN is added to form an emulsion.

Depending on the purity of the regenerated MMA, the molecular weight of the processing aid increases. As the water content increases compared to the regenerated MMA, it is easier to control the temperature in the emulsion polymerization step (S42), making it easier to increase the molecular weight of the processing aid, so it can be adjusted within the above range. You can.

The higher the content of the emulsifier, the smaller the particle size of the processing aid and the higher the molecular weight, so it can be adjusted within the above range.

The emulsion polymerization step (S42) is a step of forming a polymer emulsion through an emulsion polymerization reaction by adding an initiator to the emulsion and raising the temperature to 30 to 80°C.

In the emulsion polymerization step (S42), the polymerization temperature is 30 to 80°C, preferably 60 to 80°C.

The initiator uses potassium sulfate (KPS) and adds 0.01 to 1 part by weight. As the content of the initiator increases, the molecular weight of the processing aid decreases, so it can be adjusted within the above range.

The coagulation step (S43) is a step of coagulating the polymer processing aid by adding a coagulant to the polymer emulsion.

In the coagulation step (S43), a coagulant prepared by mixing 15% by weight of CaCl ₂ and 85% by weight of water is added to the polymer emulsion to separate water and polymer materials and form a slurry-like polymer processing aid.

The powdering step (S44) is a step of dehydrating and drying the aggregated polymer processing aid by vacuum and centrifugation to obtain a polymer processing aid powder of the desired particle size.

In the powdering step (S44), moisture is removed from the slurry-state polymer processing aid by vacuum drying and centrifugation, and a polymer processing aid powder with a moisture content of less than 1% is obtained through a hot air or spray dryer process.

Hereinafter, an embodiment including the present invention configured as described above will be constructed and the resulting effects will be closely examined.

<Test Example 1>

In order to determine the effect of the THF solvent used in the method of recovering high purity MMA from waste artificial marble according to the present invention, solvent candidates (THF, Toluen, MEK, Acetone) that can dissolve the acrylic resin in waste artificial marble were selected. And conduct a test to measure the PMMA dissolution reaction time for each solvent. The reaction temperature was tested at 60°C and a dissolution concentration of 20%, and the results showed that the solvent reaction time was fast in the order of THF > MEK > Acetone > Toluen, as shown in Table 1 below.

THF Toluen Mek Aceton 1st (reaction time) 105 150 128 132 2nd (reaction time) 110 152 117 129

<Test Example 2>

In the method of recovering high purity MMA from waste artificial marble according to the present invention, the viscosity of PMMA extracted by THA solvent was measured to confirm the estimated molecular weight. The viscosity was measured 1 to 5 times according to solubility by diluting the mixture of THA and PMMA to 1/10, and the results are shown in Table 2 below.

solubility Primary Secondary 3rd 4th 5th One% 12.27" 12.55" 12.34" 12.36" 12.46" 2% 16.94" 16.86" 16.37" 16.16" 16.15" 3% 25.31" 24.97" 24.74" 24.99" 24.81" 5% 39.13" 39.58" 39.98" 39.22" 39.44" 7% 69.34" 69.38" 71.88" 70.46" 39.35" 10% 166.51" 164.44" 167.77" 167.54" 166.49" 15% 507.58" 526.20" 480.08" 461.75" 479.72"

<Test Example 3>

In the polymer processing aid manufacturing step (S40) of the method for recovering high-purity MMA from waste artificial marble according to the present invention, the viscosity of the polymer processing aid is measured from the first to the sixth time according to reaction conditions and content of raw materials (Table 3). (Table 4) confirmed the molecular weight estimate.

Primary Secondary 3rd 4th 5th 6th Temperature (℃) 80 60 80 60 60 60 water (ml) 500 500 500 500 1000 1000 MMA(ml) 500 500 500 500 500 500 Initiator (g) 0.02 0.02 0.04 0.04 0.02 0.04 Coagulant (g) 10 10 10 10 10 10 Stirring speed 250 250 250 250 250 250

Primary Secondary 3rd 4th 5th 6th Viscosity 1 137.42 170.12 85.12 102.14 190.06 115.08 Viscosity 2 142.36 175.43 88.42 109.70 185.42 116.42 average 139.89 172.77 86.77 105.92 187.74 115.75 Molecular weight (estimated) 4 million 5 million 2.5 million 3 million 5.5 million 3.5 million

As shown in Tables 3 and 4, the higher the polymerization temperature and the larger the amount of initiator, the lower the molecular weight, and the higher the amount of water, the higher the molecular weight. Therefore, it can be seen that slowing down the overall reaction rate and conducting the polymerization reaction at an appropriate temperature is advantageous in obtaining a polymer processing aid.

In addition, Figure 5 shows the viscosity and relative viscosity of ready-made polymer processing aids (pa828, pa912, pa932, pa950, pa970) and the polymer processing aid according to the present invention over the first to fifth rounds based on a polymerization temperature of 40°C. As shown in the comparison graph, the average viscosity of the polymer processing aid according to the present invention was measured to be 68.594, and it can be confirmed that it is manufactured as a polymer processing aid of about 10 million when converted to the expected molecular weight.

<Test Example 4>

A yield (conversion rate) calculation test was conducted for polymer processing aids using the manufacturing process of acrylic resin and alumina from waste artificial marble according to the prior art and the method for recovering high purity MMA from waste artificial marble according to the present invention, and the results were reported. Compare.

1) The MMA recovery process according to the prior art largely consists of the following processes: waste artificial marble → aerobic low-temperature pyrolysis → amorphous pseudo-boehmite → dissolution → impurity removal → filtration → precipitation.

The raw material consists of 162 kg of acrylic resin, which accounts for 45% of 360 kg of waste artificial marble, and 198 kg of aluminum hydroxide, which accounts for 55%.

In aerobic low-temperature pyrolysis, about 36 L and 6 L of gaseous acrylic resin are present in the main tank and outlet collection tank, respectively, so that a total of 42 L of gaseous acrylic resin is obtained. When converted to the specific gravity of the acrylic resin (0.956 g/L), the obtained acrylic resin is calculated to be 40 kg, which represents a yield of about 25% compared to the 162 kg of acrylic resin present in the waste artificial marble, which is the raw material.

When 2% acrylic resin (4L) is included in 183L of condensate obtained in the subsequent step, the yield can be calculated to be about 27%. Of the unobtained acrylic resin, 94 kg was released into the atmosphere during dust collection, and 24 kg was believed to have been contained in pipelines and raw materials.

Through an aerobic low-temperature pyrolysis reaction of waste artificial marble, amorphous pseudoboehmite with gaseous acrylic resin removed was dissolved → impurities removed → filtration → precipitation → white-colored aluminum hydroxide was obtained, and this aluminum hydroxide was subjected to a high-temperature sintering process. Approximately 125 kg of Al ₂ O ₃ powder was collected.

This corresponds to a yield of about 63% _, but among 198 kg of aluminum hydroxide present in the waste artificial marble, which is _the raw material, the moisture ( _{H 2 O} ) is at the level of 35%, and the calculated yield is about 95%, excluding 3.7 kg of Al ₂ O ₃ that escaped as pure dust. In addition, a total of 183L of condensate was collected throughout the process. Excluding about 60% of this, which corresponds to moisture absorbed from the external air, the actual moisture obtained from the raw materials was found to be about 71L, which is the total weight of waste artificial marble, which is the raw material. It can be seen that moisture was captured in an amount equivalent to about 19.5% of 360kg (2% of this includes acrylic resin).

In other words, when 360 kg of waste artificial marble is input, the final collected amount is 40 kg of acrylic resin, 125 kg of Al ₂ O ₃ powder, and 71 kg of condensate. As a result, a total of 165 kg of recycled raw materials (acrylic resin and Al ₂ O ₃ powder) was obtained, and the overall yield was calculated to be about 45.8%.

2) According to the method of recovering high purity MMA from waste artificial marble according to the present invention as described above, liquid phase separation step (S10) → PMMA acquisition step (S20) → recycled MMA acquisition step (S30) → polymer self-processing agent manufacturing step ( S40) is performed and the yield is calculated. The content of raw materials input in the polymer processing agent manufacturing step (S40) is 300 kg of water, 100 kg of MMA, 1 kg of initiator, and 2 kg of emulsifier.

The yield measurement method is Net Total (total input) × TSC (total solid content) - (emulsifier + initiator) = (water + initiator + emulsifier + MMA) × (initiator + emulsifier + PA) / (water + initiator + emulsifier + MMA ) - Same as (emulsifier + initiator). TSC is the solid content ratio when water and MMA monomer are blown away from the sample collected at 105°C and only the solid content remains.

Therefore, for example, when intermediate sample collection (A = 100g) and collected solids (B = 24g), TSC is B/A = 0.24, so yield (conversion rate) = 403Kg × 0.24 - (1+2) = 93.72%. Therefore, it was confirmed that the yield according to the present invention was significantly higher than that of the prior art.

The method for recovering high-purity MMA from waste artificial marble according to the present invention as described above provides a method for separating high-purity MMA from components contained in waste artificial marble and recycling it for the production of polymer processing aids.

Since the present invention is processed at a very low temperature compared to the prior art, it has the advantage of overcoming the problems of reduced purity and yield that occur in the existing high temperature heat treatment process.

In addition, the present invention has the effect of significantly saving energy and contributing to improved productivity by pyrolyzing only the acrylic resin recovered through solvent extraction at low temperature compared to the conventional method of pyrolyzing 100% of the entire waste artificial marble by weight at high temperature.

In addition, the present invention can produce polymer processing aids or acrylic resins through emulsion polymerization of recycled MMA, so it has various effects such as replacing the existing imports of polymer processing aids, so it is expected to have great industrial applicability. .

S10: Liquid phase separation step
S20: PMMA acquisition step
S21: First dissolution step
S22: Secondary dissolution step
S23: PMMA recovery step
S30: Regenerative MMA acquisition stage
S31: MMA gas recovery step
S32: Condensed MMA recovery step
S33: MMA recovery stage
S40: Polymer self-processing manufacturing stage
S41: Emulsion composition step
S42: Emulsion polymerization step
S43: Aggregation step
S44: Powdering step

Claims (7)

A liquid phase separation step (S10) of extracting the pulverized waste artificial marble with a solvent to separate solid inorganic substances and obtain a liquid extract containing acrylic resin;
A PMMA obtaining step (S20) in which PMMA is obtained by reacting the liquid extract obtained in the liquid phase separation step (S10) with a tetrahydrofuran solvent,
A method for recovering high purity MMA from waste artificial marble, comprising a regenerated MMA obtaining step (S30) of purifying the PMMA obtained in the PMMA obtaining step (S20) by a vacuum depolymerization reaction to obtain recycled MMA. According to claim 1,
In the PMMA acquisition step (S20),
A primary dissolution step (S21) in which the acrylic resin is recovered by first reacting the liquid extract obtained in the liquid phase separation step (S10) with a tetrahydrofuran solvent,
A secondary dissolution step (S22) in which the acrylic resin recovered in the first dissolution step (S21) is subjected to a secondary reaction with a tetrahydrofuran solvent to dissolve low-molecular-weight organic compounds and recover the undissolved acrylic resin,
A method for recovering high-purity MMA from waste artificial marble, comprising a PMMA recovery step (S23) of fractionating the acrylic resin recovered in the secondary dissolution step (S22) to separate impurities and recovering PMMA. According to claim 2,
In the first dissolution step (S21) and the second dissolution step (S22),
The reaction temperature is raised to 66°C, which is the boiling point of the tetrahydrofuran solvent, and the solvent and acrylic resin that evaporate and condense to the top of the reactor are recovered.
In the PMMA recovery step (S23),
A process for recovering high-purity MMA from waste artificial marble, characterized in that distilled water, CaCl, and NaCl are added to acrylic resin and fractionated distillation is performed at a temperature of 60 ~ 65 ℃ to phase separate water and aluminum hydroxide, solvent, and PMMA and recover PMMA. method. According to claim 1,
In the regenerative MMA acquisition step (S30),
An MMA gas recovery step (S31) in which gaseous MMA is recovered by vacuum depolymerization of PMMA obtained in the PMMA acquisition step (S20),
A condensed MMA recovery step (S32) in which condensed MMA is recovered by heating and distilling the gaseous MMA recovered in the MMA gas recovery step (S31),
Recovering high-purity MMA from waste artificial marble, comprising an MMA recovery step (S33) of fractionating the condensed MMA recovered in the condensed MMA recovery step (S32) to separate the water layers and recovering purified recycled MMA. method. According to claim 4,
In the MMA gas recovery step (S31),
PMMA is put into a vacuum chamber and decomposed at a temperature of 200 to 250°C in a vacuum of 0.1 Torr or less to recover gaseous MMA.
In the condensed MMA recovery step (S32),
In the distillation device, the condensed MMA that is distilled together with water is recovered by heating at a temperature of 101°C, which is the boiling point of MMA,
In the MMA recovery step (S33),
A method for recovering high purity MMA from waste artificial marble, comprising the steps of fractionating condensed MMA at a temperature of 95 to 100°C to separate water and MMA and recovering purified recycled MMA in the upper layer. According to claim 1,
Recovering high purity MMA from waste artificial marble further comprising a polymer self-processing aid manufacturing step (S40) of producing an acrylic polymer processing aid by emulsion polymerizing the recycled MMA obtained in the recycled MMA obtaining step (S30). method. According to claim 6,
In the polymer self-processing preparation step (S40),
An emulsion composition step (S41) in which water and regenerated MMA are added to the reactor at a weight ratio of 1:1 to 5, an emulsifier is added, and then stirred to form an emulsion;
An emulsion polymerization step (S42) in which an initiator is added to the emulsion and the temperature is raised to 30 to 80° C. to form a polymer emulsion through an emulsion polymerization reaction;
A coagulation step (S43) in which a coagulant is added to the polymer emulsion to coagulate the polymer processing aid,
A method for recovering high purity MMA from waste artificial marble, comprising a powdering step (S44) of dehydrating and drying the aggregated polymer processing aid by vacuum and centrifugation to obtain polymer processing aid powder of the desired particle size. .