JPH11114517A - Method for decomposing pcb - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently decompose PCB at a low cost by mixing the PCB in an aluminum-iron oxide mixture, thereafter igniting the resultant mixture and decomposing the PCB by the heat of reaction generated at the time when the iron oxide is reduced by the aluminum. SOLUTION: A mixture prepd. by mixing powdery aluminum with iron oxide at a ratio of about 1:3 is mixed with crushed PCB and a binder and the resultant lump mixture are formed and successively, charged in a melting furnace and ignited by the heat in the melting furnace. Then, the aluminum and the iron oxide cause a ther mitereaction, the iron oxide is reduced by the aluminum and the PCB is instantaneously decomposed into gaseous carbon dioxide and water by the heat of reaction (about 2,000 deg.C) generated at the time of the reduction. Since the PCB is easily decomposed under an atmospheric pressure further, without vaporizing it, no a noxious material is generated and this method is also excellent in safety.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for disassembling a PCB.

[0002]

2. Description of the Related Art PCB (short for polychlorinated biphenyl) is
Depending on how chlorine enters biphenyl, several compounds are known, but all are chemically stable, and combined with other excellent physical properties, are widely used as insulating oils, heat carriers, etc. However, because it is toxic to the human body and caused pollution, it is currently not produced,
Rather, because of its chemical stability, its decomposition treatment has become a social problem.

Conventionally, as a method for decomposing PCBs, for example, a method of first decomposing by ultraviolet irradiation and then a second decomposition by microorganisms, or a method of converting water into critical water at about 200 atm and at about 400 ° C. in such critical water A method of decomposing PCB into hydrochloric acid, carbon dioxide gas and water has been used.

[0004]

However, in the above-mentioned conventional method for decomposing PCBs using microorganisms, a long time is required for the decomposition process, and a large amount of PCB is decomposed in a short period of time and efficiently. I couldn't.

[0005] In addition, a PCB using the above-mentioned conventional critical water is used.
In the method of decomposing water, it was necessary to apply a high pressure of 200 atm to water, and thus there was a disadvantage that an expensive and large-scale apparatus was required.

[0006] Therefore, in the above-mentioned conventional method for decomposing a PCB, it was not possible to decompose the PCB at low cost and efficiently.

[0007]

Therefore, according to the present invention, PCB is mixed into a mixture of aluminum and iron oxide, then ignited, and the PCB is decomposed by heat of reaction generated when the iron oxide is reduced by aluminum. It was decided to.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION In the method for decomposing a PCB according to the present invention, first, powdery aluminum and iron oxide are substantially
The crushed PCB is mixed with the binder into the mixture mixed in the ratio of 3 to form a bulk mixture. Incidentally, magnesium may be mixed as a ketalizer.

Next, the mass mixture is sequentially charged into a melting furnace, and the mass mixture is ignited by heat in the melting furnace.

Then, a thermite reaction occurs between the aluminum and the iron oxide, and the iron oxide is reduced by the aluminum.

That is, Fe ₂ O ₃ + 2Al → Al ₂ O ₃ + 2Fe + 200 Kcal PCB is instantaneously decomposed into carbon dioxide gas and water by the heat of reaction generated at about 2000 ° C.

As described above, according to the present invention, the PCB can be easily decomposed under normal pressure, and the decomposition process of the PCB, which has become a social problem, can be performed.

Further, no special device for disassembling the PCB is required, and no special material is required.

Further, since PCB is instantaneously decomposed into carbon dioxide gas and water, it can be decomposed without vaporizing the PCB, and no toxic substances are generated when decomposing the PCB. It is also excellent in terms of.

[0015]

[Example] First, powdered aluminum 1Kg and iron oxide 3K
The mixture was mixed with 10 kg of crushed PCB together with a binder into 4 kg of a mixture obtained by mixing with 10 g of magnesium and 10 mg of magnesium as a ketalizer to form a bulk mixture.

Next, the mass mixture is sequentially charged into a melting furnace, the mass mixture is ignited by the heat in the melting furnace, and the reaction heat generated when the iron oxide is reduced by aluminum is about 2000 ° C.
Thereby instantaneously decomposed the PCB into carbon dioxide and water.

[0017]

The present invention is embodied in the form described above, and has the following effects.

That is, according to the present invention, PCB can be easily decomposed under normal pressure, and PC which has become a social problem
B can be decomposed.

Moreover, no special device is required, and
The PCB can be disassembled without the need for special materials.

Further, since PCB is instantaneously decomposed into carbon dioxide gas and water, it can be decomposed without vaporizing the PCB, and no toxic substances are generated when decomposing the PCB. It is also excellent in terms of.

Claims (1)

[Claims] 1. A mixture of aluminum and iron oxide with PC
A method for decomposing a PCB, comprising mixing B, igniting, and decomposing the PCB by reaction heat generated when iron oxide is reduced by aluminum.