JP6860211B2 - Resin waste treatment method and resin waste treatment system - Google Patents

Description

The present invention relates to a method for treating resin waste containing carbon fibers and a system for treating resin waste containing carbon fibers.

In recent years, cement manufacturing facilities have been using these as raw materials and fuels in order to effectively utilize wastes such as construction-generated soil, sludge, soot, food-based wastes, and waste plastics. In particular, a large amount of scrapped automobile shredder dust (ASR: Automobile Shredder Residue) is generated year by year, and the need for efficient treatment is increasing.

Waste car shredder dust is a residue obtained by cutting waste cars with a large cutter at a recycling factory and then separating and recovering valuable resources such as iron through a magnetic separator, etc., mainly organic synthetic polymer substances such as plastics, rubber, and sponges. It is mainly composed of combustible materials and inorganic substances such as glass. In recent years, from the viewpoint of improving the strength and weight reduction of vehicles, carbon fiber reinforced plastics (CFRP: Carbon Fiber Reinforced Plastics) containing carbon fibers as these constituents, fiber reinforced plastics (FRP: Fiber Reinforced Plastics), and carbon Fiber-reinforced thermosetting resins (CFRTS: Carbon Fiber Reinforced Thermosets) and carbon fiber-reinforced thermoplastic resins (CFRTP: Carbon Fiber Reinforced Thermoplastics) have come to be used (see, for example, Patent Document 1).

Normally, when treating waste automobile shredder dust with a cement manufacturing facility, generally, like other industrial wastes, these combustible wastes such as calciners and kilns are used as fuel at about 700 to 1300 ° C. It is put into the combustion field. Conventionally, a detailed study of the charging position (see, for example, Patent Document 2) and a study of the combustion atmosphere (see, for example, Patent Document 3) have been carried out.
However, in recent years, when processing resin members using carbon fiber for these scrapped automobile shredder dust, the carbon fiber causes an electric discharge in the electrostatic precipitator of the exhaust gas treatment equipment, and the electrostatic precipitator stops, which hinders the operation of cement manufacturing. Turned out to cause. Although general resin members are heat-treated in a combustion field, some carbon fibers do not burn in the above temperature range, and the non-combustible carbon fibers pass through the preheater together with the exhaust gas. Since carbon fibers are fibrous, they may be entangled in various devices or pipes and cause problems that hinder the operation of cement equipment. In particular, stopping the electrostatic precipitator will lead to a serious accident.

Japanese Unexamined Patent Publication No. 2013-212730 Japanese Patent No. 5112141 Japanese Patent No. 4948429

Therefore, in the present invention, even if the resin waste containing carbon fiber is used as a fuel, the resin waste can be treated efficiently without hindering the operation of the cement facility, and the resin waste. The purpose is to provide a processing system for goods.

As a result of diligent research to solve the above problems, the present inventors have found that the problems can be solved by filtering the scattered substances containing carbon fibers generated after the heat treatment and collecting the scattered substances. The heading has completed the present invention. That is, the present invention is as follows.

[1] A method for treating resin waste containing carbon fibers, wherein the resin portion of the resin waste is heated to separate the carbon fibers, and the heating / separation step is generated. Including a recovery step of filtering the scattered matter containing carbon fibers and recovering the scattered matter.
A method for treating resin waste in which the resin waste containing carbon fibers is heated to 800 to 1300 ° C. in the heating / separation step.
[2] The method for treating resin waste according to [1], wherein the heating in the heating / separation step is performed by at least one of a preheater, a calcining furnace, a kiln butt, and a rotary kiln of a cement manufacturing apparatus.
[3] The method for treating resin waste according to [1] or [2], wherein the filter treatment in the recovery step is a treatment by a bag filter.
[4] The method for treating resin waste according to any one of [1] to [3], wherein an electrostatic precipitator treatment is performed after the filter treatment.
[5] The method for treating resin waste according to any one of [1] to [4], wherein the resin waste containing carbon fibers is automobile shredder dust.
[6] A treatment system for treating resin waste containing carbon fibers, in which a heating means for heating the resin portion of the resin waste by heating and a scattering substance containing the carbon fibers generated after the heating are filtered. A resin waste treatment system comprising a recovery means for recovering the scattered matter, wherein the heating means heats the resin waste containing carbon fibers to 800 to 1300 ° C.
[7] The resin waste treatment system according to [6], wherein the collection means is a bag filter.
[8] The resin waste treatment system according to [6] or [7], further comprising an exhaust chimney and an electrostatic precipitator, wherein the electrostatic precipitator is located between the exhaust chimney and the collection means.

According to the present invention, a resin waste treatment method capable of efficiently treating the resin waste without disturbing the operation of the cement facility even if the resin waste containing carbon fiber is used as a fuel, and the resin waste. A processing system for goods can be provided.

It is a schematic diagram which shows one form of the resin waste treatment system containing carbon fiber.

[1. Method for treating resin waste containing carbon fiber]
First, as a composite material using carbon fiber, there are carbon fiber reinforced plastic, carbon fiber reinforced carbon composite material and the like. Carbon fiber is rarely used as a single material, and is mainly used as a composite material in combination with a base material such as synthetic resin.
The method for treating resin waste containing carbon fibers of the present invention includes a heating step of heating the resin portion to melt or burn it, and specifically, a preheater of a cement manufacturing apparatus, a calciner, a kiln, and a kiln. It is put into at least one of the heating field or the combustion field of the rotary kiln, and the resin component of the resin waste containing carbon fibers is melted or burned to separate the carbon fibers.

As for the conditions of combustion treatment, the conditions performed in the cement manufacturing facility are applied. For example, the processing temperature is about 750 to 1050 ° C. (preferably 850 to 950 ° C.) in the calcining furnace, and about 950 to 1250 ° C. (preferably 1000 to 1200 ° C., more preferably 1000 to 100 ° C.) in the kiln butt. Is.

It is preferable that the resin waste containing carbon fibers is divided into predetermined sizes in advance. In the treatment method according to the present invention, when the resin component is heated, the resin component is melted or burned, and the carbon fiber portion is separated from the resin component without burning. The carbon fiber separated from the resin part flows to the preheater along with the gas flow. The treatment method according to the present invention includes a recovery step of filtering the scattered matter containing carbon fibers and recovering the scattered matter. Specifically, the step is a step of recovering the carbon fibers scattered from the preheater with a filter.

By such treatment, the flammable resin component of the resin waste containing carbon fibers will eventually burn as a part of the fuel. That is, the resin component is used as fuel. There are various types of carbon fibers, some of which burn at 600 ° C or lower and some of which do not burn at 1450 ° C. However, almost all carbon fibers do not melt at about 1450 ° C. There are PAN-based (Polyacrylonitrile) made by carbonizing acrylic fiber at high temperature and pitch-based (PITCH) made from pitch (a by-product of petroleum, coal, coal tar, etc.), but all of them have a melting point. -There are high temperature decomposition points of 2000 to 3500 ° C.
Therefore, after the combustion treatment, scattered matter containing carbon fibers will be generated. This scattered material scatters together with the exhaust gas, and if it is mixed in the electrostatic precipitator, for example, there may be a problem that electricity is supplied via carbon fibers, and the operation may have to be stopped. In addition, a large amount of the scattered material may be scattered and stay in other equipment or piping, causing various problems.
The present invention is particularly effective for resin waste containing PAN-based or pitch-based carbon fibers.

In the present invention, a scattered matter recovery treatment is performed in which the scattered matter containing the carbon fibers generated after the combustion treatment is filtered and the scattered matter is recovered. As a result, the scattered matter can be removed from the exhaust gas, so that the operation of the cement equipment is not hindered, and the subsequent exhaust gas treatment process is not hindered or the efficiency is not lowered.

The scattering material recovery treatment includes treatment with a bag filter, water washing treatment of exhaust gas with a scrubber, treatment with a large sedimentation chamber, etc., but treatment with a bag filter is preferable in consideration of capital investment and treatment cost.

Here, as the material used for the filter cloth of the bag filter, polypropylene, nylon, acrylic, polyester, cotton, wool, heat-resistant nylon, polyamide / polyimide, PPS (polyphenylene sulfide), glass fiber, PTFE (polytetrafluoroethylene). ), Etc., and examples of the functional filter cloth include a catalyst-supporting filter and an electrostatic filter. Among them, suitable filter cloths are heat-resistant nylon, polyamide / polyimide, PPS (polyphenylene sulfide), glass fiber, and PTFE (polytetrafluoroethylene), and more preferably heat-resistant nylon, PPS (polyphenylene sulfide), and PTFE (polytetrafluoroethylene). Fluoroethylene).
Further, examples of the pay-off method include a pulsating reverse pressure method and a pulse jet method, and among them, the pulse jet method is a preferable pay-off method.

After the filter treatment, it is preferable to perform an electrostatic precipitator treatment. By performing the electrostatic precipitator treatment, it is possible to recover the fine dust from the treated exhaust gas and prevent the fine dust from diffusing from the smoke exhaust equipment.
Since the electrostatic precipitator treatment is performed after the carbon fibers are separated and recovered by the filter treatment, no failure due to the carbon fibers occurs.

Examples of resin waste containing carbon fibers include waste automobile shredder dust, boats, floor tubs, fishing rods, golf clubs and other wastes, molds, wash basins, bathtubs, interior materials, etc., and resin components as fuel. Considering the large amount of processability of the waste automobile shredder dust, the waste automobile shredder dust is preferable.
Further, the carbon fibers in the waste automobile shredder dust remain without being burned by the heating applied to cement production, but in the present invention, the carbon fibers are used while preventing problems caused by the carbon fibers in such a case. Can be separated and collected. Considering this viewpoint, scrapped automobile shredder dust is preferable.

Here, scrapped automobile shredder dust is crushed to a size of about 100 mm with a large crusher (shredder) after removing reusable parts and parts from the scrapped automobile, and valuable metals are sorted by magnetic force sorting or hand sorting. It is crushed waste that remains after recovery.

When the scrap car shredder dust is charged into at least one of the preheater and the rotary kiln, it is preferable to adjust the particle size of the waste vehicle shredder dust according to the respective charging locations.

When charged into a preheater (particularly a calcining furnace), the particle size (maximum particle size) of the scrap car shredder dust is preferably 15 mm or less, more preferably 10 mm or less. When thrown into a rotary kiln, it is preferably thrown into the kiln butt, and the particle size (maximum particle size) of the waste automobile shredder dust at that time is preferably 40 mm or less, more preferably 30 mm or less.
As a method for dividing by particle size, a known method such as using a sieve can be applied.

Waste automobile shredder dust often contains chlorine-containing resin components such as polyvinyl chloride and other chlorine-containing plastics; chloroprene rubber used as automobile window frames (weather strips); Therefore, if this is directly burned, dioxin may be generated, and corrosion of equipment due to hydrogen chloride may become a problem. In addition, the chlorine content of the product cement increases. Therefore, in the present invention, it is preferable to appropriately perform desalination treatment.
Examples of the desalting treatment include washing of chlorine-containing waste with water. Alternatively, there is a desalination treatment in which chlorine-containing dust and chlorine gas are discharged from the cement equipment to the outside of the system by extracting high-temperature gas between the kiln bottom of the cement equipment and the lowermost cyclone of the preheater. By adopting these desalting treatments, the amount of waste automobile shredder dust treated can be increased.

According to the resin waste treatment method of the present invention, the cement equipment can be operated stably even if the resin waste containing carbon fibers that can hinder the operation of the cement equipment is used as fuel.
Further, since the scattered matter separated and recovered by filtering the scattered matter contains carbon fibers, it can be reused as a reinforcing fiber used for fiber reinforced concrete or the like. Alternatively, the recovered fiber can be mixed with cement and used as a fiber premix cement used for fiber reinforced concrete or the like.

[2. Resin waste treatment system containing carbon fiber]
FIG. 1 shows an outline of an embodiment of a resin waste treatment system containing carbon fibers of the present invention. The system is suitable for carrying out the above-mentioned method for treating resin waste of the present invention. Therefore, the various conditions described below are also applicable to the resin waste treatment method of the present invention.

In the resin waste treatment system 10 shown in FIG. 1, resin waste containing carbon fibers is charged into at least one of the preheater 12, the rotary kiln 14, the preheater 12, the calciner 12A, the kiln tail 13, and the rotary kiln 14. The resin waste input means 16 is included. In FIG. 1, the resin waste is charged into the kiln tail 13 of the rotary kiln by the resin waste input means 16, but this is an example, and the present invention is not limited to this aspect.
Hereinafter, an example of the treatment outline of the resin waste treatment system of the present invention will be described with reference to the drawings. In FIG. 1, the solid arrow indicates the flow of the raw material, and the dotted arrow indicates the flow of the exhaust gas.

First, the cement raw material stored in the cement raw material storage 18 is dried and crushed by the raw material mill (cement raw material drying and crushing machine) 20, passed through the cyclone (cement raw material powder separating machine) 22, and then stored in the raw material silo 23. , Is charged into the preheater (suspension preheater) 12. While being heated by the preheater (suspension preheater) 12, it passes through the preheater 12 and is sent to the calcination furnace 12A.
In the preheater 12, the raw material is heated at about 300 to 900 ° C., and then in the calcining furnace 12A, the raw material is heated at about 800 to 1300 ° C. The raw material heated in the calcining furnace 12A is further heat-treated in the rotary kiln 14. The resulting clinker is transported to the clinker cooler 26, which is then pulverized and subjected to a known cement production process.

Here, the resin waste input means 16 inputs the resin waste containing carbon fibers to at least one of the preheater 12, the calcining furnace 12A, the kiln tail 13, and the rotary kiln 14, so that the resin waste is contained in the resin waste. The resin component is heated and melted, and part or all of it is burned and consumed as fuel. Further, since the resin component is melted or burned by heating, the carbon fiber and the resin component are separated.

When the resin waste is charged into the calcining furnace 12A by the resin waste charging means 16, the maximum particle size of the resin waste is 15 mm or less in the range from the ceiling to the bottom of the calcining furnace 12A up to 40% from the ceiling. Is preferable. Further, it is preferable to charge resin waste having a maximum particle size of 40 mm or less in the range from 40% or more to the bottom of the calcining furnace 12A.

Since carbon fiber in resin waste is incombustible, it is not used as fuel, and because it is light, it scatters in the direction opposite to the raw material supply direction along with the flow of exhaust gas generated during combustion (dotted line in the figure). See arrow).

When the scattered matter containing carbon fibers generated after the combustion treatment is mixed into the electrostatic precipitator, for example, there is a problem that the air is energized through the carbon fibers, and the operation may have to be stopped. In addition, when a large amount of the scattered material is scattered, it may adhere to or stay in other equipment or piping, causing various problems.

Therefore, in FIG. 1, in the flow direction of the exhaust gas, a scattered matter collecting means 28 is provided on the upstream side of the electrostatic precipitator 30, and the scattered matter containing carbon fibers generated after the combustion treatment is filtered to recover the scattered matter. ing.
As a result, only the exhaust gas containing no carbon fiber is sent to the electrostatic precipitator 30, where the dust is further recovered, and finally the exhaust gas is discharged from the exhaust chimney 32.

As the scattered material collecting means 28, it is preferable to use a bag filter, and a filter made of a heat-resistant material is particularly preferable. With the bag filter, it is possible to remove not only carbon fiber but also unburned carbon that was not burned out by coal as fuel without any trouble even if it scatters, and suppresses operational interruption due to unburned carbon in the electrostatic precipitator. can do. If the dust collection performance of the bug filter is good, the electrostatic precipitator 30 can be stopped or removed.
Here, as the electrostatic precipitator 30, a type in which the rectification method is a silicon type and the dust collector chamber is three chambers can be used. The gas flow velocity passing through the dust collecting chamber of this electrostatic precipitator can be operated at about 0.5 to 1.5 m / s.

A fan (not shown) is provided between the electrostatic precipitator 30 and the exhaust chimney 32 to provide a function of keeping the flow rate and flow velocity of the exhaust gas passing through the electrostatic precipitator 30 and the bag filter 28 constant by a control device. You may.

Further, as the cement raw material that can be used in this resin waste treatment system, for example, limestone, clay raw material, siliceous raw material such as silica stone, iron oxide and the like obtained by excavating and collecting naturally occurring ore are used. In addition to the finely pulverized and mixed cement raw materials, one or more kinds of wastes including inorganic wastes, organic wastes, inorganic wastes and organic wastes can be used.
As the inorganic waste, coal ash containing residual carbon, blast furnace slag, blast furnace dust, unburned ash and the like are used, and these inorganic wastes are suitable as substitutes for clay raw materials.

On the other hand, as the organic waste, for example, waste containing organic substances such as waste plastic, waste tire, and waste oil is used. These wastes are relatively easy to treat among the wastes treated in cement manufacturing facilities. For example, waste plastics, waste tires, etc. are cut or coarsely crushed and then used as a part of fuel. It is directly put into the rotary kiln 14 or the calcining furnace 12A and melted and burned.

According to the above-mentioned carbon fiber-containing resin waste treatment system, cement can be produced while effectively using the carbon fiber-containing resin waste as fuel. In addition, the operation of the cement facility due to carbon fiber is not hindered, and the resin waste can be treated efficiently.

10 ... Processing system 12 ... Preheater 12A ... Temporary firing furnace 13 ... Kiln butt 14 ... Rotary kiln 16 ... Resin waste input means 18 ... Cement raw material storage 23 ... Raw material Silo 28 ... Scattered material recovery means 32 ... Chimney

Claims (5)

A method for treating resin waste containing PAN-based carbon fiber or pitch-based carbon fiber in a cement manufacturing facility.
The cement manufacturing facility includes a heating means which is a calcining furnace and a recovery means provided on the downstream side in the flow direction of the exhaust gas generated by the heating means.
The resin waste is put into the heating means, the resin waste is heated to 800 to 1300 ° C. in the heating means, the resin component of the resin waste is melted , and a part or all of the resin component is melted. The heating process to burn and
A recovery step in which the scattered matter containing the carbon fibers generated through the heating step is conveyed to the recovery means together with the flow of the exhaust gas, and the scattered matter is recovered from the exhaust gas by treatment with a bag filter in the recovery means. including the door, the processing method of the resin waste. The method for treating resin waste according to claim 1, wherein an electrostatic precipitator treatment is performed after the filter treatment. The method for treating resin waste according to claim 1 or 2 , wherein the resin waste containing carbon fibers is automobile shredder dust. A treatment system that treats resin waste containing carbon fiber in cement manufacturing equipment.
A heating means that is a calcining furnace and a recovery means provided on the downstream side in the flow direction of the exhaust gas generated by the heating means are provided, and the recovery means is a bag filter.
The carbon fiber is a PAN-based carbon fiber or a pitch-based carbon fiber, and the carbon fiber is
Wherein the resin waste to the heating means is turned on, the heating means heats the resin waste 800 to 1300 ° C., the resin component of the resin waste is melted and burning some or all of the resin component Let me
Scattering comprising the carbon fibers produced by the heating means, with the flow of the exhaust gas conveyed to the collecting means, you recover the debris from the exhaust gas to filter in the collecting means, the resin waste system. Equipped with an exhaust chimney and an electrostatic precipitator,
The resin waste treatment system according to claim 4 , wherein the electrostatic precipitator is located between the exhaust chimney and the collection means.

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