JPH11188335A - Method for treating waste copper wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To establish a treatment method for plastic-coated waste copper wire which improves investment efficiency. SOLUTION: Plastic-coated waste copper wire is subjected to dry distillation treatment at 300-45 deg.C in a non-oxidative atmosphere in a heating furnace, an exhaust gas containing hydrogen chloride gas is discharged, hydrochloric acid is recovered from the exhaust gas, the copper wire with the adherent unmelted residue containing carbon is recovered, finally the copper wire is cut, and the copper wire from which the residue containing carbon is removed is obtained. The investment efficiency of recycling waste carbon wire improves. Hydrochloric acid, copper, and a reducing agent/fuel are recovered mainly from vinyl chloride resin-coated copper wire.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of treating a waste copper wire having a plastic coating, and more particularly to a method of treating a waste copper wire mainly having a vinyl chloride coating by dry distillation (smoking).

[0002]

2. Description of the Related Art Among waste copper wires, thick wires are recycled by nugget, but thin wires and waste copper wires with oil are treated by open burning and the like, leading to environmental destruction. Also, even if the incinerator is properly treated, the hydrogen chloride gas generated causes corrosion, and the equipment, including the combustion chamber and gas treatment equipment, is damaged in a short period of time due to corrosion, and is not optimal from the viewpoint of global environmental protection. At present, it has not been recycled effectively and has not been practically used. Furthermore, the generated hydrogen chloride and / or chlorine gas is not recycled at all. Coatings, especially vinyl chloride or rubber or mixtures thereof, also contain significant amounts of fillers, and oiling studies have been performed, but due to reasons such as hydrochloric acid generation and low oiling rates. At present, they are hardly collected and used and are sent to managed landfills. There are many types and a large number of fine wires that are difficult to make into nuggets, such as wires for automobiles, wires for electronic and communication equipment, and wires for windings. In particular, the volume of discarded vinyl chloride-coated copper wires related to the printed circuit boards of electronic devices is rapidly increasing, and the fact is that it is difficult to take measures against such disposal.

[0003] Such waste treatment generally has poor investment efficiency, requires too much capital investment compared to the profit obtained by recycling, and is a major barrier to practical use. In the case of recycling general waste copper material, the copper recovered by waste treatment must eventually pass through a purification treatment and an electrolytic treatment, and the investment efficiency is poor at present. In particular, waste copper wire has a high plastic coating / copper ratio, and its treatment is more difficult.

Several techniques for treating polyvinyl chloride pyrolysis gas have been proposed for the purpose of reducing the volume and recycling of polyvinyl chloride plastic. For example, a vinyl chloride pyrolysis gas and absorption water are introduced simultaneously through a processing pipe, the introduced vinyl chloride pyrolysis gas is dissolved in the absorption water, and a mixed solution containing hydrochloric acid and phthalic anhydride is generated. There has been proposed a method in which phthalic anhydride in the mixed solution is precipitated as crystals in an internal tank, and hydrochloric acid overflowing is collected in a liquid receiving tank surrounding the internal tank. However, here, waste copper wire is not involved and only the purpose of reducing the volume and recycling of polyvinyl chloride plastic alone is required.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a waste copper wire having a coating of plastics to reduce the value of the waste copper wire so that the investment efficiency can be improved and the global environment can be protected. The purpose is to establish a processing method for thorough use.

[0006]

In order to improve the investment efficiency of waste copper wire and to protect the global environment, if the copper wire inside plastic coating can be recovered in a solid state without melting, the recovered copper The wire can be used, for example, as a copper alloy additive, which is very convenient. Therefore, the present inventor has conceived of decomposing only the plastic coating without melting the copper wire by the dry distillation treatment to obtain a vinyl chloride pyrolysis gas. Vinyl chloride starts volatilizing at 270 ° C. By subjecting waste copper wire having a plastics coating to dry distillation in a non-oxidizing atmosphere at a temperature of 300 to 450 ° C. in a heating furnace, exhaust gas containing hydrogen chloride gas is discharged, and hydrochloric acid is recovered from the exhaust gas. It has been found that the copper wire with the residue containing carbon can be recovered in an unmelted state. The residue containing copper after carbonization was chopped, and it was also found that the residue was brittle and could be easily separated from copper.

Thus, the present invention provides: (1) a waste copper wire having a plastics coating is subjected to dry distillation in a non-oxidizing atmosphere at a temperature of 300 to 450 ° C. in a heating furnace to remove exhaust gas containing hydrogen chloride gas; Discharging, recovering hydrochloric acid from the exhaust gas, and recovering the copper wire to which carbon-containing residue has adhered in an unmelted state, and (2) waste copper having a plastic coating The wire is subjected to dry distillation in a non-oxidizing atmosphere at a temperature of 300 to 450 ° C. in a heating furnace to discharge exhaust gas containing hydrogen chloride gas, recover hydrochloric acid from the exhaust gas, and attach a copper wire to which a residue containing carbon has adhered. , In a non-molten state, cutting the copper wire, and removing a residue containing carbon to obtain a high-grade secondary copper raw material, thereby providing a method for treating a waste copper wire. A representative example of the waste copper wire is a vinyl chloride-coated copper fine wire associated with a printed circuit board of an electronic device. The present invention is the first attempt to recover hydrochloric acid, copper, and a reducing agent / fuel mainly from a vinyl chloride-coated copper wire, and to thoroughly utilize the value of the waste copper wire.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is directed to waste copper wire having a chloride-based plastic coating such as vinyl chloride and vinylidene chloride. Among them, a thick wire is recycled by nugget, and particularly a thin wire. Copper wires with oil or oil, typically wires for automobiles, wires for electronic and communication equipment, wires for winding, etc., which are difficult to make into nuggets, especially vinyl chloride-coated copper wires related to printed circuit boards for electronic devices. set to target.

According to the present invention, such a waste copper wire is subjected to dry distillation in a non-oxidizing atmosphere at a temperature of 300 to 450 ° C. in a heating furnace (drying furnace). FIG. 1 shows the flow of the method of the present invention. The waste copper wire is subjected to dry distillation (smoking) in a dry distillation furnace such as an externally heated electric furnace. As a heat source, a factory waste heat source can also be used. Dry distillation refers to decomposing only the chloride-based plastic coating without melting the copper wire inside the coating, leaving the copper wire unmelted, and discharging it as exhaust gas containing hydrogen chloride gas. Polyvinyl chloride starts volatilizing at 270 ° C. But 3
Below 00 ° C. Insufficient dry distillation treatment can be performed,
On the other hand, when the temperature exceeds 450 ° C., softening of the residue on the surface of the copper wire starts, and it becomes difficult to separate the subsequent copper wire from the coating residue. Due to the large energy required for carbonization, 500 ℃
It is desired to utilize more than a degree of waste heat or combustion heat of the recovered residue.

The generated hydrogen chloride or chlorine gas is used for recovering hydrochloric acid. The recovered hydrochloric acid has a quality of 20% or more and meets at least the provisions of JIS No. 2,
Can be usefully reused. The obtained hydrochloric acid can be used, for example, for regeneration of a chelating resin. The exhaust gas after the recovery of hydrochloric acid is subjected to gas treatment by combustion or the like, and is desirably used as a heat source for dry distillation as described above.

[0011] The copper wire to which the residue containing carbon in the heating furnace adheres is recovered in an unmelted state, and is subjected to a vibration / sieving / crushing step. The residue attached to the copper wire is brittle and can be easily removed from the copper. Deposits can also be washed off by washing with a washing machine equipped with a stirrer. The residue contains, in addition to carbon, lime added to the coating. If necessary, pickling may be performed. The separated residue is
It can be used as a reducing agent / fuel in a non-ferrous smelting process.

In this way, a copper wire having a metal color surface is obtained, which can be used as it is as an additive for alloying, and can be recycled as a repetition product in a copper smelting process such as a refining furnace or a converter / casting melting furnace. can do.

As described above, the present invention has succeeded in recovering hydrochloric acid, copper, and a reducing agent / fuel mainly from a vinyl chloride-coated copper wire, and makes full use of the value of the waste copper wire. .

[0014]

EXAMPLE A vinyl chloride-coated copper fine wire connected to a printed circuit board of an electronic device was carbonized at 380 ° C. for 3 hours in an argon atmosphere in an externally heated electric furnace. Exhaust gas containing hydrogen chloride gas discharged from the heating furnace was treated to obtain hydrochloric acid having a concentration of 20%. On the other hand, the copper wire recovered from the heating furnace was able to remove deposits such as carbon by vibrating, sieving, and crushing, and could be reused as it was. The copper wire collected from the heating furnace was able to wash off the deposits by washing.

[0015]

According to the present invention, the copper wire inside the chloride-based plastic coating is recovered in a solid state without melting, and the hydrochloric acid is recovered at the same time. Contributes to the
The investment efficiency of waste copper wire recycling can be greatly improved. The separated residue can be used as a reducing agent / fuel in the non-ferrous smelting process. Thus, the present invention succeeds in recovering hydrochloric acid, copper, and a reducing agent / fuel mainly from a vinyl chloride-coated copper wire, and greatly contributes to global environmental conservation through thorough use of the value of the waste copper wire.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a flow for implementing the method of the present invention.

Claims (3)

[Claims] 1. A waste copper wire having a plastic coating is subjected to dry distillation in a non-oxidizing atmosphere at a temperature of 300 to 450 ° C. in a heating furnace to discharge an exhaust gas containing hydrogen chloride gas. And recovering the copper wire to which carbon-containing residue has adhered in an unmelted state. 2. A waste copper wire having a plastic coating is subjected to dry distillation in a non-oxidizing atmosphere at a temperature of 300 to 450 ° C. in a heating furnace to discharge an exhaust gas containing hydrogen chloride gas. A copper wire to which carbon-containing residue is attached in an unmelted state, cutting the copper wire, and removing the carbon-containing residue to obtain a high-grade secondary copper raw material. Copper wire processing method. 3. The method for treating a waste copper wire according to claim 1, wherein the waste copper wire is a vinyl chloride-coated copper fine wire associated with a printed circuit board of an electronic device.