JP2000285756A - Dechlorination method of coating waste of vinyl chloride coated wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To recycle a vinyl chloride coated wire waste as fuel by removing calcium and lead as sediment from a solution of the vinyl chloride coating wire waste dissolved in a solvent by centrifugal separation, and heating the vinyl chloride resin component separated from the solvent by distillation of the solution in a thermal decomposing furnace of a specified temperature to remove chlorine. SOLUTION: The coating waste of a vinyl chloride coated wire is dissolved in a 10 times the quantity of THF, calcium and lead are settled by use of a centrifuge, and the solvent of the supernatant after removing the sediment is made to evaporate. The resulting solid containing 0.5% or less of calcium and 0.1% or less of lead (vinyl chloride resin component) is pulverized and put into a rotary kiln type thermal decomposing furnace A, using a ceramic ball 2 through a hopper 1. The solid is thermally decomposed in the thermal decomposing furnace A at 300-450 deg.C for 90 minutes, hydrochloric acid is recovered in a recovery tank 4 by the use of the water of an injection tank 3 and a cooler 5, and a carbon component having low chlorine quantity of 1% is recovered in a receiving tray 6 as fuel. According to this, waste can be efficiently disposed of.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating of a vinyl chloride-coated electric wire for efficiently removing chlorine from the waste, by recovering the used PVC-coated electric wire and reusing the dismantled electric wire covering waste material as fuel. The present invention relates to a dechlorination treatment method for removing chlorine from waste materials.

[0002]

2. Description of the Related Art Electric wires, particularly electric wires wired outdoors, are replaced after a certain period of use in consideration of their safety. The replaced waste wire is separated into a conductor (mainly copper) and a covering material (mainly resin). Of the separated coating materials, the coating waste materials consisting of petroleum-based materials are converted to fuel and reused as alternative energy to petroleum (recycling)
However, the reuse (recycling) of coating waste mainly composed of vinyl chloride resin has been delayed, and since chlorine is contained, it is hoped that an effective recycling method including environmental issues will be developed. It is rare. The coating resin composition of the polyvinyl chloride-coated electric wire is polyvinyl chloride 1 which is a chlorine-based chemical substance.
1 to 8 parts of a lead stabilizer, 30 to 70 parts of a plasticizer (phthalic ester), and 20 to
About 60 parts are included. Combustion treatment of such a waste material composed of a vinyl chloride resin composition generates hydrogen chloride (sometimes dioxin) and lead oxide, and cannot be burned as fuel at present because of environmental harm. They cannot be used as fuel, and they are all landfilled.

[0003]

For this reason, various studies and proposals have been made on methods for removing chlorine from vinyl chloride resin waste material in order to effectively recycle the coating waste material of the vinyl chloride coated electric wire. For example, a method in which waste materials coated with vinyl chloride-coated electric wires are put into a rotary kiln-type pyrolysis furnace and heated with stirring to dechlorinate (JP-A-10-11093)
Several methods such as 1) have been proposed. However, when such a thermal decomposition method was tested on waste materials of vinyl chloride-coated electric wires, it was extremely difficult to reduce the amount of chlorine in the thermal decomposition residue to 10% or less. The inventors of the present invention have conducted intensive studies on the cause, and found that calcium carbonate and a lead stabilizer contained in the vinyl chloride-coated electric wire covering material supplement chlorine released by thermal decomposition of the vinyl chloride resin, and as a result, after heat treatment. It was found that the total chlorine content in the residue could not be reduced to 10% or less. Since PVC chloride-coated electric wires have been laid in large quantities since the high-growth period, it is expected that the number of waste wires will increase rapidly in the future, and it is urgently necessary to develop a method for dechlorinating coated waste materials from waste wires. It is becoming.

[0004]

DISCLOSURE OF THE INVENTION The present invention solves the problems associated with the dechlorination of coated waste materials of discarded vinyl chloride-coated electric wires, effectively reuses the coated waste materials as fuel, and is environmentally friendly. An object of the present invention is to provide an excellent dechlorination treatment method. The present invention dissolves vinyl chloride-coated electric wire coating waste material in a solvent, removes calcium and lead from the solution by centrifugation as a precipitate, and distills the solution from which the precipitate has been removed to remove the solvent and the vinyl chloride resin component. And removing the chlorine by heating the vinyl chloride resin component in a pyrolysis furnace at 300 ° C. to 450 ° C. to remove chlorine. In particular, the present invention removes calcium by centrifugation to 0.5% or less from the solution in which the vinyl chloride-coated electric wire coating waste material is dissolved, or removes lead by centrifugation to 0.1% or less, or removes calcium by 0.1% or less. Remove 5% or less and lead to 0.1% or less,
By distilling and pyrolyzing the solution from which calcium and lead have been removed in the next step, chlorine can be efficiently removed from the coating waste material. In the method for dechlorinating vinyl chloride-coated electric wire covering waste material of the above invention, when the vinyl chloride-coated electric wire covering waste material is dissolved in a solvent having an amount of 4 to 30 times the amount of the waste material, the waste material consists of calcium and lead efficiently by centrifugation. Sediment can be removed. Further, by using a rotary kiln type pyrolysis furnace containing ceramic balls as the pyrolysis furnace used in the present invention, the pyrolysis efficiency can be further improved and chlorine can be removed efficiently.

In the present invention, as described above, first, sediment composed of calcium and lead is removed from the polyvinyl chloride-coated electric wire covering waste material by centrifugation. Next, the solution obtained by separating and removing these components is distilled to separate into a solvent and a vinyl chloride resin component. The separated vinyl chloride resin is then subjected to a thermal decomposition treatment. The pyrolysis residue obtained by pyrolysis is reused as alternative energy to petroleum. According to the present invention, the chlorine concentration can be reduced to such an extent that the pyrolysis residue (carbon content) can be used as a petroleum alternative energy (fuel). In particular, in order to reduce chlorine as much as possible from vinyl chloride resin waste material, the vinyl chloride resin waste material is added to the waste material by 4 to 30 minutes.
After dissolving in a double amount of a solvent (for example, tetrahydrofuran), the solution is centrifuged, and calcium and lead are removed by precipitation using a specific gravity difference. In this way, the calcium content is reduced to 0.5% or less by the centrifugal separator, and the amount of lead is also reduced to 0.5%.
By removing it to 1% or less, chlorine that has been captured in calcium or lead as CaCl ₂ or PbCl ₂ generated in the next pyrolysis step is not captured, and the chlorine concentration in the residue after the pyrolysis treatment becomes extremely low. Environmental conditions for reusing the residue for fuel can be cleared.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. First, a waste electric wire is separated into a copper conductor and a vinyl chloride resin coating material. In the separation work, make a vertical cut in the coating resin with a blade,
The conductor and the covering can be separated easily by tearing along the cut. The separated conductor is regenerated into a new copper product by melting treatment. On the other hand, the coating waste material made of vinyl chloride resin is finely cut and dissolved with a solvent. As a solvent for dissolving the coating waste material made of vinyl chloride resin, tetrahydrofuran (hereinafter referred to as THF)
Dimethylsulfoxide, ethylene chloride, methylene chloride, tetralin and the like. The dissolution depends on the amount of the resin, but it depends on the amount of the resin so as to obtain a concentration (viscosity) suitable for removing calcium and lead by centrifugation in the next step.
It is preferable to dissolve in 0 times the amount of the solvent. Concentration (viscosity)
If the concentration is too high, calcium and lead are difficult to settle in the centrifugation step, making removal difficult.If the concentration is too small, calcium and lead become easy to remove, but the consumption of solvent increases, and energy is also required for solvent removal. And wasting time is not economical.

[0007] The solution from which the precipitate consisting of calcium and lead has been separated by the centrifugal separator is separated into a solvent and a vinyl chloride resin which has become solid in the next step. For the separation, the solution is put into an evaporator, the solvent is evaporated and recovered, and the vinyl chloride resin component is taken out as a solid. To remove chlorine from the residue to a chlorine level that does not cause a problem even if the residue after the pyrolysis treatment is reused as a solid fuel, that is, a chlorine content that has almost no environmental problem, put it in a pyrolysis furnace. It is necessary to reduce the content of calcium or lead in the solid matter (vinyl chloride resin component). This is because calcium and lead contained in the solid matter increase chlorine concentration in the pyrolysis residue by capturing chlorine generated in the pyrolysis step as CaCl ₂ and PbCl ₂ . For this reason, in order to keep the chlorine concentration in the residue within a range in which the residue can be reused, the residual amount of calcium contained in the solid material fed into the pyrolysis furnace is 0.5% or less and lead is 0.1% or less.
%. If the residual amounts of calcium and lead are 0.5% and 0.1% or more, respectively, the amount of chlorine contained in the residue after pyrolysis is undesirably large. The ratio of solvent to waste material to properly remove calcium and lead is
The most preferable range is to dissolve the solvent in an amount of 4 to 30 times the amount of the waste material. The solids removed from the solvent are thermally decomposed in a heat treatment furnace and separated and recovered as carbon, hydrochloric acid and some oil. The recovered carbon is used as blast furnace fuel or solid fuel, and hydrochloric acid is a chemical. The oil is reused as a liquid fuel. Pyrolysis furnace temperature is 3
The range of 00 ° C to 450 ° C is preferred. Temperature 300
If the temperature is lower than ° C, dechlorination is not sufficient, and organic chlorine remains in the residue (carbon), so that it cannot be converted into a solid fuel,
On the other hand, if the temperature is higher than 450 ° C., the proportion of carbon useful as an alternative energy to petroleum decreases.

Further, as the heat treatment furnace, a rotary kiln type pyrolysis furnace is preferable, and a furnace containing a ceramic ball which is less likely to be corroded by hydrochloric acid is particularly preferable. It is preferred that the inner wall surface of the furnace is also subjected to anticorrosion treatment by applying a ceramic paint. The solid matter (vinyl chloride resin component) charged into the rotary kiln-type pyrolysis furnace is heated in the furnace and beaten and crushed by rotating ceramic balls, and dispersed to promote the release of chlorine. The use of a rotary kiln pyrolysis furnace with ceramic balls
This is because the dechlorination operation can be completed in a short time. If the time for the thermal decomposition in the thermal decomposition furnace is too short, the vinyl chloride resin component is not sufficiently thermally decomposed, and the organic chlorine remains in the residue. Therefore, a thermal decomposition time of 30 minutes or more is required. However, care must be taken if the length is too long, since energy such as fuel is wasted. Since the pyrolyzed residue (carbon content) contains almost no chlorine, it is unlikely to cause pollution problems even when used as a solid fuel, so it can be used as a raw material for blast furnaces, wood chips, or other plastic chips. , Paper, etc. (for adjusting the calorific value) can be reused as a solid fuel.

[0009]

[Example 1] For testing electric wire covering waste materials, the same composition as the electric wire sheath material, vinyl chloride resin 51%, phthalic acid ester (plasticizer) 26%, tribasic lead sulfate (lead stabilizer)
2.6% (lead content 2.2%), calcium carbonate (filler)
A vinyl chloride resin composition blended with 21% (calcium content: 8.4%) was prepared and extruded by an extruder to prepare a sample for test (for wire covering waste material). This sample was finely ground and dissolved in THF 10 times the amount of the sample, and calcium and lead were precipitated by a 15,000 G centrifuge.

Next, the supernatant liquid from which the precipitate has been removed is placed in a solvent evaporation vessel at about 70 ° C. (the boiling point of THF is about 65 ° C.).
(° C), the solvent was recovered by distillation. As a result of analyzing the solid (vinyl chloride resin component) remaining after volatilization of the solvent, calcium was 0.33% and lead was 0.1%. The remaining solid matter (vinyl chloride resin component) from which the solvent was evaporated was finely crushed and put into a pyrolysis furnace, where it was pyrolyzed at 350 ° C. for 90 minutes. For the pyrolysis, a rotary kiln type pyrolysis furnace A using the ceramic balls 2 shown in FIG. 1 was used. The above-mentioned solvent was volatilized, and the finely crushed solid was put into the hopper 1, and the solid was put into the rotary kiln type pyrolysis furnace A from the hopper 1. The solid material is heated and softened in the furnace, and is beaten by the ceramic ball 2 rotating together with the solid material, whereby pulverization and dispersion progress, and dechlorination is promoted.

In the figure, reference numeral 3 denotes a water injection tank for injecting water into the furnace A to promote a hydrolysis reaction of a phthalate ester contained in a solid substance. Reference numeral 5 denotes a cooler for cooling hydrogen chloride and low-molecular-weight carbon compounds generated as a gas. The cooled hydrogen chloride is recovered as hydrochloric acid in the recovery tank 4, and the low-molecular-weight carbon compounds are converted into oil components on the hydrochloric acid. Since it floats, it can be separated and recovered as hydrochloric acid and oil. The pyrolysis reaction was completed in about 90 minutes, and the residue (carbon content) was discharged from the furnace A to the tray 6. As a result of analyzing the amount of chlorine contained in the residue, the amount of chlorine was extremely low as 1.0%, and it was possible to mix it properly with other fuels to form a solid fuel, and to obtain the latest chlorine-free fuel. The chlorine concentration was at a level that could be used as a fuel for a combustion furnace (an incinerator having a device that supplements some chlorine contained in the raw material and does not discharge it outside the furnace).

[0012]

Example 2 A dechlorination treatment was performed in the same manner as in Example 1 except that the sample was dissolved in THF 15 times. As a result, calcium was added to the solid (vinyl chloride resin content) remaining after volatilization of the solvent of the supernatant liquid after centrifugation.
02% and lead remained 0.06%, and the amount of chlorine contained in the residue after pyrolysis was 0.8%. As described above, by increasing the amount of the solvent, that is, by decreasing the solution concentration (viscosity), calcium and lead can be efficiently removed by the centrifugal separator, and the amount of chlorine contained in the residue also decreases. However, the time required to evaporate the solvent was about three times that of Example 1.

[0013]

[Comparative Example] A sample prepared in Example 1 was tripled with TH
F and calcium and lead were precipitated in a 15,000 G centrifuge. As a result of evaporating the solvent of the supernatant liquid from which the precipitate was removed and analyzing the remaining solid matter (vinyl chloride resin content), calcium was 7.2% and lead was 0.13%. Next, the solid was thermally decomposed under the same conditions as in Example 1 and the amount of chlorine contained in the residue was analyzed. As a result, the amount of chlorine was 13.2.
%, And had a slightly high chlorine content to be used as the latest incinerator fuel or as a raw material for solid fuel.

[0014]

Conventional Example The sample prepared in Example 1 was directly introduced into the pyrolysis furnace used in Example 1, subjected to pyrolysis under the same conditions as in Example 1, and the amount of chlorine contained in the residue after pyrolysis was analyzed. As a result, the chlorine content was extremely high at 21.3%, and the chlorine content was too large to be directly used as a raw material for a solid fuel or the like, which was inappropriate.

[0015]

As described in detail above, according to the method for dechlorination of vinyl chloride coated electric wire covering waste material, the chlorine concentration in the residue decomposed in the pyrolysis furnace is low, and the latest combustion equipment (dechlorination function Can be reused as fuel. In addition, the residue can be used as a raw material for solid fuel, and in the case of renewing a polyvinyl chloride-coated electric wire, which is expected to increase in the future, the coated waste can be efficiently treated in a recyclable state, and the process is simple. And the like.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a rotary kiln type pyrolysis furnace used in the present invention.

[Explanation of symbols]

 A rotary kiln type pyrolysis furnace 1 hopper 2 ceramic balls 3 water injection tank 4 collection tank 5 cooler 6 saucer

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4D004 AA08 AB06 AC05 BA03 CA13 CA24 CB09 CC04 DA02 DA06 4F301 AA17 CA08 CA09 CA12 CA42 CA52 CA53 CA72 4H015 AA02 AA17 AB01 BA01 BA08 BB03 BB12 CB01

Claims (5)

[Claims] 1. A method for dissolving waste coating material of a vinyl chloride-coated electric wire in a solvent, removing calcium and lead as sediment from the solution by centrifugation, and distilling the solution from which the sediment has been removed to obtain a solvent and a vinyl chloride resin. A method for dechlorinating vinyl chloride-coated electric wire covering waste material, comprising separating a vinyl chloride resin component by pyrolysis in a pyrolysis furnace at 300 ° C. to 450 ° C. to remove chlorine. 2. 0.5% (weight%, hereinafter the same) of calcium from a solution in which a coating waste material of a vinyl chloride coated electric wire is dissolved.
2. The method for dechlorination of vinyl chloride-coated electric wire covering waste material according to claim 1, wherein the waste material is removed by centrifugation until: 3. The method according to claim 1, wherein calcium is removed from the solution in which the coating waste material of the vinyl chloride-coated electric wire is dissolved to 0.5% or less and lead to 0.1% or less by centrifugation.
A method for dechlorination of a vinyl chloride-coated electric wire covering waste material as described above. 4. A waste material coated with a vinyl chloride-coated electric wire according to claim 1, wherein the waste material coated with the vinyl chloride-coated electric wire is dissolved in a solvent having an amount of 4 to 30 times the amount of the waste material. Dechlorination treatment method. 5. The coating according to claim 1, wherein the pyrolysis furnace according to claim 1 is a rotary kiln type pyrolysis furnace containing ceramic balls. How to dechlorinate waste materials.