JPH07241352A - Treatment for making polychlorobiphenyl (pcb) attached article harmless - Google Patents

Abstract

PURPOSE:To provide the treatment for making harmless a polychlorobiphenyl (PCB) attached article and a substance containing PCB that is harmful for the human body and is difficult of decomposing in the natural world. CONSTITUTION:A substance such as an insulating oil containing PCB is extracted from a PCB attached article, cleaned, and dried or decomposed at a temperature of 500 deg.C or more, and is added into a metal-refining melting furnace for refining metal at a high temperature exceeding 1100 deg.C separatedly or together with the substances containing PCB, so that the PCB is subjected to thermal decomposion and is made harmless. The ink, pressure sensitive paper, or the like for a copying machine containing PCB may be added into the metal-refining melting furnace as it is. As to the metal-refining melting furnace, a converter or the like for refining steel is preferable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detoxifying used or un-used PCB deposits that are industrial waste. Here, the PCB deposits include a transformer using a substance such as insulating oil containing PCB, a capacitor using a substance such as insulating oil containing PCB, and various electric parts using a substance such as insulating oil containing PCB. Say

[0002]

2. Description of the Related Art Polychlorinated Biphenyl (PCB) is
Chloride is a general term for Biphenyl and chloride is 2, 3, 4,
It is a mixture of 5 and 6. PCB is physically and chemically stable, has excellent heat resistance and electrical insulation, and is used alone or mixed with other mineral oils or insulating oils to produce insulating oil, heat carrier, lubricating oil, and Has been widely used in industrial products in inks containing PCBs, copying materials containing PCBs such as pressure-sensitive copying paper, and the like.

However, since it has been found that these PCB-containing substances are harmful to the human body and are environmental pollutants which are difficult to decompose in the natural world, the production of PCB has been stopped and, on the other hand, used A product containing PCB from which the PCB has been collected or stored is desired to be detoxified. Although many researches and developments have been conducted so far on the technology for detoxifying PCB deposits, the technology actually practiced on an industrial scale today is the high temperature pyrolysis method. .

Regarding the detoxification treatment of liquid PCBs, the US Environmental Protection Agency has instructed that the residence time at 1200 ° C. be kept for 2 seconds or more, and that the spray combustion be performed. DSDuvall, WAR
According to the paper by ubey et al. (1977), PCB is 600 ℃
Pyrolysis begins with 1 second exposure, and at 800 ℃ or higher, 99.9% of the pyrolysis will occur in 1 second. Here made from carbon, hydrogen and chlorine as PCB, molecular formula is a compound represented by _{C 12 H (10-N)} Cln (n is 2-6). The detailed physical and chemical properties of these substances have already been clarified, and as mentioned above, they are known to almost completely decompose in a time of 1 second or less in a high temperature oxidizing atmosphere of 600 ° C or higher. There is. Therefore, 11
At high temperature of 00 ℃ or more, for example, 99.999 in 0.3 seconds or less.
It is known to decompose up to 9 (6-nine).

Therefore, Japanese Patent Application Laid-Open No. 2-232073 proposes a method for detoxifying a transformer having polychlorinated biphenyl attached thereto. In this method, the PCB is removed from the transformer, etc., and the transformer main body to which the PCB is attached is left as it is, or after separating the container and internal components, they are placed in a solid heating furnace and heated to a temperature of less than 1100 ° C. ,
In this method, PCBs adhering to these solids are vaporized and separated, and further ignited to decompose them at high temperature to render them harmless.
Japanese Unexamined Patent Publication (Kokai) No. 2-241586 proposes a method for detoxifying a capacitor having polychlorinated biphenyl attached thereto. In this method, liquid PCB is extracted from the condenser in advance, a part of the condenser is separated into a container part and an internal part, and these are used in the same or different incinerator, and the temperature is 1100 ° C or higher or 1400 ° C or lower. PC discharged from the incinerator while keeping the temperature and incinerating
It proposes a method of detoxifying the B vapor and combustion gas by using them in a pyrolysis furnace maintained at a high temperature of 1200 ° C. or more and 1500 ° C. or less for further pyrolysis.

[0006] By the way, regarding the PCB itself, a liquid PCB is used by using an incineration treatment apparatus of organic chlorine compound waste liquid.
An apparatus for thermally decomposing and treating methane at a high temperature has also been developed (environmental chemistry vol. 19, No. 12 (1990)). In such a thermal decomposition treatment furnace or treatment device, a spray nozzle is devised to complete the thermal decomposition of PCB, and the combustion temperature is set to about 1800.
The temperature is set to ℃, and the temperature at the outlet of the decomposition furnace is maintained at 1450 ℃. Furthermore, the residence time in the high temperature gas was set to 2 seconds or more in this furnace, and the generated HCl was absorbed in water without being recovered.
The method of directly neutralizing the absorbed water is adopted. In addition, undecomposed PCBs in exhaust gas and wastewater and dioxin (PCDD _S ) and dibenzofuran (PCDF _S ), which are harmful substances that may be by-produced, pose a problem, but even if these components are discharged, they will be discarded. Both gas and wastewater are passed through an activated carbon adsorption tank to absorb and remove them.

[0007]

However, in any of the above-mentioned methods for treating PCB deposits, first, a low-temperature incinerator is used for incineration, and then PCB vapor and combustion gas discharged from this oven are further separated. This is a method of introducing it to a pyrolysis furnace to perform high-temperature pyrolysis. Therefore, specially designed incinerators and pyrolysis furnaces are required and the operation of the equipment is expensive. Today these equipment and operating costs cannot be ignored. Therefore, the current situation is that the discarded PCB is stored in a container and left to stand. However, during long-term storage, the stored PCB may leak from these containers and become a source of pollution. Therefore, these P
It is desired to develop a method for economically detoxifying CB deposits.

[0008]

[Means for Solving the Problems] As a result of diligent research on such a problem, the inventors have found that if an existing metal refining / melting furnace is used, new equipment is not required, and metal refining / melting
Based on the idea that PCBs can be rendered harmless while melting, without requiring special equipment costs and without extra operating costs therefor, the inventors have made the following inventions.

(1) The invention of claim 1 is a method for detoxifying a polychlorinated biphenyl (hereinafter referred to as PCB) deposit, which comprises the following steps. (A) PCB to PC
Metal refining for refining at a high temperature of 1100 ° C. or higher in a step of extracting a substance containing B, and (b) a PCB deposit obtained by extracting the substance containing PCB alone or together with a substance containing the extracted PCB.・ Add to melting furnace
The process of thermally decomposing CB to render it harmless.

(2) The invention of claim 2 is a method for detoxifying a polychlorinated biphenyl (hereinafter referred to as PCB) deposit, which comprises the following steps. (A) PCB to PC
A step of removing the substance containing B, and (b) cleaning the PCB deposit from which the substance containing the PCB has been extracted, or
A treatment step of drying at a temperature of not less than ℃, or a temperature of not less than 500 ℃ after washing, and (c) the treated PCB deposit alone,
Or, together with the substance containing the extracted PCB, 11
A step of adding to a metal refining / melting furnace for refining at a high temperature of 00 ° C. or higher to thermally decompose the PCB to render it harmless.

(3) The invention of claim 3 is a method for detoxifying a polychlorinated biphenyl (hereinafter referred to as PCB) deposit, which comprises the following steps. (A) PCB to PC
Extracting a substance containing B, (b) decomposing the PCB adhering substance from which the substance containing PCB is extracted into a container, an iron part and a copper part, and (c) washing the decomposed container and part, Or a treatment step of drying at 500 ° C. or higher, or after washing and drying at 500 ° C. or higher, and (d) the treated container or part alone or the extracted P
A step of adding a substance containing CB together to a metal refining / melting furnace for refining at a high temperature of 1100 ° C. or higher to thermally decompose the PCB to render it harmless.

(4) The invention of claim 4 is a method for detoxifying a polychlorinated biphenyl (hereinafter referred to as PCB) deposit, which comprises the following steps. (A) PCB to PC
A step of removing the substance containing B, and (b) cleaning the PCB deposit from which the substance containing the PCB has been extracted, or
A treatment step of drying at or above ℃ or drying after washing at 500 ℃ or above, (c) a step of decomposing the treated PCB deposit into a container, an iron part and a copper part, and (d) the dried container, The parts alone or the extracted P
A step of adding a substance containing CB together to a metal refining / melting furnace for refining at a high temperature of 1100 ° C. or higher to thermally decompose the PCB to render it harmless.

(5) According to the invention of claim 5, the copying material containing PCB is used alone or in combination with other PCB deposits.
This is a method of adding to a metal refining / melting furnace for refining at a high temperature of ℃ or higher to thermally decompose the PCB to render it harmless.

(6) The invention of claim 6 is a method for detoxifying polychlorinated biphenyl (hereinafter referred to as PCB) deposits according to any one of claims 1 to 5, wherein the metal refining / melting furnace is a converter. is there.

Here, as the metal refining / melting furnace, at least 11 in terms of completely decomposing the PCB as described above.
It is a metal refining / melting furnace operated at 00 ° C or higher,
Also, it is necessary to have a source of oxygen into the furnace, which is convenient for pyrolyzing the PCB. As such a refining / melting furnace, for example, a converter in a steel mill, an electric furnace for refining using oxygen, an open furnace, or a converter in copper refining is suitable.

[0016]

[ Operation ] Treatment of PCB deposits PCB deposits are roughly classified into two types: transformers and capacitors. Although there are some other electrical components, most of them can be treated by either a transformer or a capacitor. First, considering the treatment method for transformers, the transformer has 20
The core consists of about 28 wt% of silicon steel sheet which is an iron core and about 12 wt% of copper. The insulating oil containing PCB is composed of, for example, 60% of PCB and 40% of trichlorobenzene, and its weight is 36% of the whole transformer. In addition, paper and synthetic rubber account for 4%. In addition, small transformers have a capacity of 100 kvA or less, while large transformers have a capacity of 100 kvA or more. Looking at a 100 kvA transformer, the total weight of insulating oil is about 1250 kg and the amount of insulating oil is 290 kg.

Looking at the transformer of 500 kvA, the total weight reaches about 3800 kg and the capacity of insulating oil reaches 940 kg. Therefore, mild steel excluding copper, silicon steel sheet and the like can be used as scrap of steel materials. When copper is added to steel,
It is an undesirable element because it generally causes hot cracking.
Therefore, in the case of a large transformer, it is desirable to remove the insulating oil containing PCB, and then to remove copper when it is used as steel scrap. Insulating oil also reaches about 36% of the total weight of the transformer, so it is necessary to drain it in advance.

Next, focusing on the condenser, there are various sizes of condenser, but the container is mainly made of mild steel, and its weight reaches about 16 wt%. Also,
Insulating oil containing PCB is about 44 wt%, other insulating paper is 23 wt%, aluminum foil is 14 wt%, other metal 2
%, And the insulator is 1% by weight. Same 100 kvA
Compared to the transformer of the
The latter is relatively small at 68 kg, compared to 290 kg. Therefore, the capacitor after removing the insulating oil can be used as it is as scrap mainly composed of steel. Therefore, for the condenser, after removing the PCB,
It can be used as it is as steel scrap.

For the transformer, after removing the insulating oil,
Insulating oil that has penetrated into the gaps in the iron core is first washed with kerosene, dried in a drying oven at 500 ° C or higher, and if necessary decomposed to make scrap material. For large transformers (with a weight of 200 kg or more), first remove the insulating oil, then disassemble it into a container, iron core, and coil, individually wash the oil, and dry them in a drying oven at 500 ° C or above. Since the boiling point of PCB is 300 to 400 ° C, it can be evaporated by drying at a temperature of 500 ° C or higher.

A container mainly composed of steel and an iron core can be used as scrap for steel, and a coil-based product such as a coil can be used as a raw material for copper refining, for example. In addition,
At the time of the drying, care should be taken so that the PCB vapor generated is not polluted by being adsorbed on, for example, activated carbon. Besides this,
As mentioned above, PCB-containing substances include copier ink and pressure-sensitive copying paper, but since the PCB content is low, it can be easily pyrolyzed if added directly to the metal refining / melting furnace. Is.

Thermal decomposition treatment of PCB The thermal decomposition reaction of PCB is estimated to be, for example, according to the following formula. In the case of biphenyl trichloride, the following reaction formula is assumed and the calorific value is as follows. C ₁₂ H ₇ Cl ₃ + 13O ₂ = 12CO ₂ + 3HCl + 2
H ₂ O ΔH ₁ = 5540 kcal / kg C ₁₂ H ₇ Cl ₃ +7 O ₂ = 12CO + 3HCl + 2H ₂
O ΔH ₂ = 2382 kcal / kg The reaction proceeds according to the first equation when the oxygen partial pressure is sufficiently high, and according to the second equation when the oxygen partial pressure is low. In addition,
The reaction proceeds basically with similar chemical formulas for biphenyl tetrachloride and further for biphenyl pentachloride. That is, the oxygen amount and oxygen partial pressure required for the above reaction are required.

Further, it is known that the above-mentioned reaction takes place within 1 second at 1100 ° C. or higher as described above. Therefore, in order to proceed the reaction in the metal refining / melting furnace, the temperature in the furnace is at least 1100 ° C. or higher, and
Oxygen supply necessary for promoting the above reaction is required. Therefore, the above-mentioned reaction proceeds in the metal refining or melting furnace capable of causing the above reaction, or in the converter, or in the refining or melting requiring oxygen in the electric furnace or the open furnace. Below, it is examined whether or not the above reaction can be promoted in a converter.

In the converter, pure oxygen is blown from above by a lance to refine an iron bath containing carbon, that is, pig iron, and a decarburization reaction is caused to produce steel.
The gas atmosphere in the converter furnace is 70% CO gas (others, CO ₂
15%, N ₂ 13%) and the temperature is 1600 ° C. or higher. Therefore, when PCB is added to this furnace, the reaction instantly proceeds based on the above reaction formula. The PCB-containing liquid can be added into the converter by, for example, a sublance. At this time, in order to accelerate the thermal decomposition reaction of PCB, the added PC
It is desirable to add extra oxygen gas according to the amount of B. The existing top blowing converter has a waste gas facility as shown in FIG. In order to accelerate the thermal decomposition of PCB, it is desirable to add it to the metal refining furnace in the form of a spray with an oxygen-containing gas such as air.

FIG. 1 is a diagram showing a facility equipped with a so-called LD gas recovery device. C generated by the refining reaction of the converter is shown.
The O 2 gas passes through the upper hood and the radiant part, and further takes the primary dust collector and the secondary dust collector, and is finally discharged through the gas holder or the chimney. As shown in the figure,
The upper hood of the converter and the radiant part are composed of water-cooled flues, the waste gas temperature is about 1450 ° C at the upper part of the converter, and the temperature just before the primary dust collector is 1000 ° C. Usually this first
The residence time of the waste gas passing through to the next dust collector is calculated to be about 1 second. Therefore, the PCB added to the converter furnace according to the above equation is completely decomposed in the converter furnace and in the flue including the upper hood and the radiation part.

Next, the waste gas of about 1000 ° C. is sprinkled with cooling water in the part of the primary dust collector, and is rapidly cooled to, for example, a temperature of about 75 ° C. That is, since it is cooled from 1000 ° C. to about 100 ° C. at once, it is possible to prevent the generation of dioxin. At this time, most of the hydrochloric acid (HCl) in the waste gas is dissolved and absorbed in water. Further, in the secondary dust collector, the cooling water is further sprinkled and the HCl completely generated is absorbed. The wastewater that has completely absorbed hydrochloric acid (HCl) is finally recovered by a thickener via a dust remover, and can be rendered harmless by neutralizing this hydrochloric acid.

Therefore, the transformers and capacitors treated by the above-mentioned method can be charged into the converter as scrap for steel. Insulating oil and other substances containing PCBs previously extracted from these can be added to the converter during refining and both can be pyrolyzed. The economy is extremely high in that the PCB can be processed in parallel with the production of steel in the converter. Scrap containing copper as a main component such as a coil may be added to a converter for copper refining. At this time, if the activated carbon to which PCB vapor is attached during drying of a transformer or the like is added to these converters, the adsorbed PCB can be completely thermally decomposed and rendered harmless.

[0027]

EXAMPLES In the following examples, assuming that a predetermined amount of PCB is added to the furnace in a 300 ton converter, PCB is added to the furnace in a laboratory scale converter (capacity: 50 kg). The result of the experiment is 300 t
It has been expanded and organized into a converter.

As shown in Table 1, while producing low carbon steel in a 300 ton converter, 1 to 6 ton of PCB was added per charge as shown in Table 1. In Table 1, the refining time per charge is about 30 minutes, so the amount added per hour is about twice that. The amount of hydrochloric acid (HCl) generated in this case is shown in the table. Further, it can be seen that there is a certain predetermined heat generation due to the combustion caused by the thermal decomposition of PCB.

At this time, the result of calculating the so-called HCl concentration in the LD gas is shown, which is 0.24 to 1.40%, and the hydrochloric acid concentration in the waste water is extremely low at 1% or less. PCB of this degree
It was shown that the addition did not hinder the operation. In addition,
Since the amount of LD gas generated is 35,000 Nm ³ / ch, the amount of gas generated by the thermal decomposition of PCB is 5.0% or less, which is extremely small relative to the amount of converter waste gas. The amount used as cooling water in the converter is 350
It is ton / ch, and as described above, the concentration of generated hydrochloric acid (HCl) can be reduced to 1% or less.

In this way, in the upper blowing converter, a maximum of 6 tons per charge, that is, 12 tons of PC per hour
It is shown that the addition of B does not hinder the overall operation. Although the above-mentioned example is an example of a small-scale experimental converter as described above, in order to show the possibility of actual operation, it was expanded and explained to the operating conditions of a 300 ton converter. However, the present invention is not limited to this embodiment.
For example, even in an electric furnace steelmaking or a converter for copper refining that uses oxygen, the present invention can be carried out in exactly the same manner when the waste gas treatment facility is usually provided.

[0031]

[Table 1]

Example 2 In order to confirm the degree of decomposition of the organic chlorine compound in the converter and the presence or absence of dioxin generation, commercially available cutting oil (chlorine content 7 to 8%) was used as the organic chlorine compound in a 300 ton converter through a sublance. Experiments were performed. This cutting oil is a water-insoluble cutting oil specified in JIS K2241.
The addition amount is shown in Table 2, and an experiment of two charges was performed for each level of the addition amount. At this time, the components of the transformer and the capacitor treated by the above-mentioned treatment method were properly inserted. The experimental results are shown in the same table, but no organic compounds or dioxins were found in the waste gas, converter dust, or the recovered cooling water. Further, when calculated from the amount of scraps of transformers and the like that could be added in excess of that in normal operation, 40% of the amount of heat generated due to the decomposition of the added organic chlorine compound was transferred to the molten steel.

[0033]

[Table 2]

[0034]

[Effects of the Invention] An existing metal refining / melting furnace, for example, a steelmaking converter is used, and transformers, capacitors, etc., from which insulating oil and other substances containing PCB have been removed are used as scraps, and during the refining process, PCBs are also used. PCB, which is hard to decompose and may cause pollution while performing the conventional refining work and at the same time, without adding extra cost, by adding and adding, and performing thermal decomposition at the same time as refining. It is an invention that can be relatively easily burnt and decomposed, and in that respect contributes significantly to society as an environmental measure.

[Brief description of drawings]

FIG. 1 is a diagram showing a waste gas treatment facility attached to a converter.

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] May 20, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0005

[Correction method] Change

[Correction content]

Therefore, Japanese Patent Application Laid-Open No. 2-232073 proposes a method for detoxifying a transformer having polychlorinated biphenyls attached thereto. In this method, the PCB is removed from the transformer, etc., and the transformer main body with the PCB attached is left as it is, or after separating the container and internal components, they are put in a solid heating furnace and heated to a temperature of less than 1100 ° C. In this method, PCBs adhering to these solid substances are vaporized and separated, and further ignited to be decomposed at high temperature to render them harmless. Japanese Unexamined Patent Publication No. 2-241586 proposes a method for detoxifying a capacitor having polychlorinated biphenyl attached thereto. In this method, a liquid PCB is extracted from the condenser in advance, a part of the condenser is separated into a container part and an internal part, and these are used in the same or different incinerators, and the temperature of 1100 ° C or higher or 1400 ° C or lower with incineration and held at a temperature, for detoxification by further high temperature pyrolysis using a pyrolysis furnace which is held the PCB steam and combustion gases at a high temperature of 1200 ° C. or higher 1500 ° C. or less is discharged from the incinerator Proposing a method.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction content]

[0007]

However, in any of the above-mentioned methods for treating PCB deposits, first, a low-temperature incinerator is used for incineration, and then PCB vapor and combustion gas discharged from this oven are further separated. This is a method of introducing it to a pyrolysis furnace to perform high-temperature pyrolysis. Therefore, specially designed incinerators and pyrolysis furnaces are required and the operation of the equipment is expensive. Today these equipment and operating costs cannot be ignored. Therefore, the current situation is that the discarded PCB is stored in a container and left to stand. However, during long-term storage, the stored PCB may leak from these containers and become a source of pollution. Therefore, these P
It is desired to develop a method for economically detoxifying CB deposits.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction content]

[0019] For a transformer, After removing the insulating oil, the insulating oil has penetrated into the gap or the like of the core, and washed first with kerosene, which was dried in a drying oven at above 500 ° C., if a result Is decomposed and used as a scrap material. For a large transformer (with a weight of 200 kg or more), first remove insulating oil, then decompose into a container, an iron core, and a coil, individually wash the oil, and dry these in a drying oven at 500 ° C or higher.
Since the boiling point of PCB is 300 to 400 ° C, it can be evaporated by drying at a temperature of 500 ° C or higher.

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] 0024

[Correction method] Change

[Correction content]

FIG. 1 is a diagram showing a facility equipped with a so-called LD gas recovery device. C generated by the refining reaction of the converter is shown.
O gases upper hood, through the radiant section, and is discharged further I Contact between the primary dust collector and secondary dust collector, through eventually gas holder or chimney. As shown in the figure, the converter upper hood and the radiant part consist of water-cooled flues, the waste gas temperature is about 1450 ° C at the converter upper part, and the temperature just before the primary dust collector is 1000 ° C. is there. Usually, the residence time of the waste gas passing through to the first dust collector is calculated to be about 1 second. Therefore, the PCB added to the converter furnace according to the above equation is completely decomposed in the converter furnace and in the flue including the upper hood and the radiation part.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Name of item to be corrected] 0025

[Correction method] Change

[Correction content]

Next, the waste gas at about 1000 ° C. is sprinkled with cooling water in the portion of the primary dust collector and rapidly cooled to, for example, a temperature of about 75 ° C. That is, from 1000 ° C to about 100
Since it is cooled all the way to ℃, it is possible to prevent the generation of dioxin. At this time, hydrochloric acid (H
Most of Cl) is dissolved and absorbed in water. Furthermore, the second
HCl generated by further spraying of cooling water in the next dust collector
Is completely absorbed. The wastewater that has completely absorbed hydrochloric acid (HCl) is finally collected by the thickener through the dust remover.
Here, the hydrochloric acid can be rendered harmless by neutralizing it.

[Procedure correction 6]

[Document name to be amended] Statement

[Name of item to be corrected] 0027

[Correction method] Change

[Correction content]

[0027]

EXAMPLES Example 1 In the following examples, a predetermined amount of P in a 300 ton converter was used.
Assuming that CB is added to the furnace, a commercially available JIS K2241 is used in a laboratory scale converter (capacity: 50 kg).
The water-insoluble cutting oil specified in 1 above is the result of the experiment conducted by adding it to the furnace, and the experimental result is expanded to the 300 ton converter and arranged.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0033

[Correction method] Change

[Correction content]

[0033]

[Table 2] ─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] June 1, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0015

[Correction method] Change

[Correction content]

Here, the metal refining / melting furnace has at least 1 in terms of completely decomposing the PCB as described above.
It is necessary that the furnace is a metal refining / melting furnace operated at 100 ° C. or higher, and has an oxygen supply source into the furnace, which is convenient for thermally decomposing PCB.
Examples of such refining / melting furnace include, for example, a converter in an iron mill or an electric furnace (arc) for refining using oxygen .
Electric furnace, high frequency electric furnace, and other refining using electricity
(Including a melting furnace) , or an open furnace, and further a converter in copper refining are suitable. ─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] October 20, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction content]

[0002]

2. Description of the Related Art Polychlorinated Biphenyl (PCB) is
It is a generic term for chlorides of biphenyl, and is a mixture of chlorides having 2, 3, 4, 5 or 6 chlorine atoms in one molecule . P
Since CB is physically and chemically stable and has excellent heat resistance and electrical insulation, it can be used alone or mixed with other mineral oils or insulating oils to produce insulating oil, heat carrier,
Lubricating oils, inks containing PCBs, and copying materials containing PCBs such as pressure-sensitive copying paper have been widely used for industrial products.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction content]

Regarding the detoxification treatment of liquid PCBs, the US Environmental Protection Agency has instructed that the residence time is kept at 1200 ° C. for 2 seconds or more, and that it is sprayed and burned. D. S. D
uval, W.A. A. Rubay et al. ( US Environmental Agency)
According to the report, 1977), PCB started thermal decomposition by exposure at 600 ° C for 1 second, and at 800 ° C or higher,
It is said that thermal decomposition of 99.9% is performed in a second. Here consisting of carbon, hydrogen and chlorine as PCB, molecular formula is a compound represented by _{C 12 H (10- n) Cl} n (n is 2-6). The detailed physical and chemical properties of these substances have already been clarified and, as mentioned above, 60
It is known that in a high temperature oxidizing atmosphere of 0 ° C. or higher, it decomposes almost completely in a time of 1 second or less.
Therefore, at a high temperature of 1100 ° C. or higher, for example, 0.
It is known to decompose to 99.9999 (6-nine) in 3 seconds or less.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

[0006] By the way, regarding the PCB itself, a liquid PCB is used by using an incineration treatment apparatus of organic chlorine compound waste liquid.
An apparatus for thermally decomposing and treating slag at a high temperature has also been developed (Environmental Vol. 19, No. 12 (1990)). In such a thermal decomposition treatment furnace or treatment device, a spray nozzle is devised to complete the thermal decomposition of PCB, and the combustion temperature is set to about 18
The temperature is set to 00 ° C, and 1450 ° C is maintained at the decomposition furnace outlet. Furthermore, in this furnace, the residence time in the high temperature gas is set to 2 seconds or more, and the generated HCl is absorbed into water without being recovered, and the absorbed water is directly neutralized. In addition, undecomposed PCB in exhaust gas and waste water and dioxins (PCDD _S ) and dibenzofuran (PCDF _S ), which are harmful substances that may be by-produced, pose a problem, but even if these components are discharged, they will be discarded. Both gas and wastewater are passed through an activated carbon adsorption tank to absorb and remove them.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction content]

[0016]

[ Operation ] Treatment of PCB deposits PCB deposits are roughly classified into two types: transformers and capacitors. Although there are some other electrical components, most of them can be treated by either a transformer or a capacitor. Considering the treatment method for the transformer, the transformer has two
0% by weight, silicon steel plate which is the iron core is about 28% by weight,
About 12 wt% of copper mainly constitutes the winding. The insulating oil containing PCB is composed of, for example, 60 wt % of PCB and 40 wt % of trichlorobenzene, and the weight thereof is 36 wt % of the whole transformer. In addition, paper and synthetic rubber account for 4 wt %. In addition, there are transformers having a small capacity of 100 kVA or less, and large transformers having a capacity of 100 kVA or more. 100k
Looking at the vA transformer, the total weight of insulating oil is about 125.
0 kg, insulating oil is 290 kg.

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction content]

Looking at a 500 kvA transformer, the total weight is about 3800 kg, and the capacity of insulating oil is 940 kg.
Reach Therefore, mild steel excluding copper, silicon steel sheet and the like can be used as scrap of steel materials. Copper is an undesirable element because it generally causes hot cracking when added to steel. Therefore, in the case of a large transformer, it is desirable to remove the insulating oil containing PCB, and then to remove copper when it is used as steel scrap. Moreover, since the insulating oil reaches about 36 wt % of the total weight of the transformer, it is necessary to extract it in advance.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction content]

Next, focusing on the condenser, although there are various sizes of condenser, the container is mainly made of mild steel, and its weight reaches about 16 wt%. Insulating oil containing PCB is about 44 wt%, other insulating paper is 23 wt%, aluminum is 14 wt%, other metal is 2 wt %, and insulator is 1 wt %. Compared to the same 100 kvA transformer, the weight of the condenser is 290 kg for the former and 68 k for the latter.
g is relatively small. Therefore, the capacitor after removing the insulating oil can be used as it is as scrap mainly composed of steel. Therefore, the capacitor can be directly used as steel scrap after the PCB is removed.

[Procedure Amendment 8]

[Document name to be amended] Statement

[Name of item to be corrected] 0022

[Correction method] Change

[Correction content]

Further, it is known that the above-mentioned reaction occurs within 1 second at 1100 ° C. or higher as described above.
Therefore, in order to proceed the reaction in the metal refining / melting furnace, the temperature in the furnace is at least 1100 ° C. or higher, and oxygen supply necessary for promoting the reaction is required. Therefore, the above reaction proceeds in the metal refining and melting furnaces capable of causing the above reaction, or in the converter, or in the refining or melting using oxygen in the electric furnace or the open furnace. Below, it is examined whether or not the above reaction can be promoted in a converter.

[Procedure Amendment 9]

[Document name to be amended] Statement

[Name of item to be corrected] 0023

[Correction method] Change

[Correction content]

In the converter, pure oxygen is blown from above by a lance to refine an iron bath containing carbon, that is, pig iron, and a decarburization reaction is caused to produce steel.
The gas atmosphere in the converter furnace is at least 70 vol % CO gas (other than CO ₂ 15 vol %, N ₂ 13 vol %),
The temperature is over 1600 ° C, so the PCB in this furnace
When is added, the reaction instantly proceeds based on the above reaction formula. The PCB-containing liquid can be added into the converter by, for example, a sublance. At this time, in order to accelerate the thermal decomposition reaction of PCB, it is desirable to add an extra oxygen gas according to the amount of PCB added. The existing top blowing converter has a waste gas facility as shown in FIG. In order to accelerate the thermal decomposition of PCB, it is desirable to add it to the metal refining furnace in the form of a spray with an oxygen-containing gas such as air.

[Procedure Amendment 10]

[Document name to be amended] Statement

[Name of item to be corrected] 0024

[Correction method] Change

[Correction content]

FIG. 1 is a view showing equipment equipped with a so-called LD gas recovery device, and C generated by refining reaction of a converter is shown.
O 2 gas passes through the upper hood and the radiating section, and further passes through the primary dust collector and the secondary dust collector, and finally is discharged through the gas holder or the chimney. As shown in the figure,
The converter upper hood and the radiant section are composed of water-cooled flues, the waste gas temperature is about 1450 ° C. at the converter upper part, and the temperature just before the primary dust collector is 1000 ° C. Usually, the residence time of the waste gas passing through to the first dust collector is calculated to be about 1 second. Therefore, the PCB added to the converter furnace according to the above equation is completely decomposed in the converter furnace and in the flue including the upper hood and the radiation part.

[Procedure Amendment 11]

[Document name to be amended] Statement

[Name of item to be corrected] 0025

[Correction method] Change

[Correction content]

Next, the waste gas at about 1000 ° C. is sprinkled with cooling water in the portion of the primary dust collector and rapidly cooled to, for example, a temperature of about 75 ° C. That is, from 1000 ° C to about 100
Since it is cooled all the way to ℃, it is possible to prevent the generation of dioxin. At this time, hydrochloric acid (H
Most of Cl) is dissolved and absorbed in water. Furthermore, the second
HCl generated by further spraying of cooling water in the next dust collector
Is completely absorbed. The wastewater that has completely absorbed hydrochloric acid (HCl) is finally collected by the thickener through the dust remover.
Here, this hydrochloric acid can be rendered harmless by neutralizing it with a neutralization tank as shown in FIG .

[Procedure Amendment 12]

[Document name to be amended] Statement

[Name of item to be corrected] 0027

[Correction method] Change

[Correction content]

[0027]

EXAMPLE 1 The following examples 300 in ton converter assuming the case of adding a predetermined quantity of PCB in the furnace, the furnace of the PCB in a laboratory scale converter of (capacity 50 kg) Add
The result of the experiment was 300 tons.
It has been expanded and organized into n converters.

[Procedure Amendment 13]

[Document name to be amended] Statement

[Name of item to be corrected] 0029

[Correction method] Change

[Correction content]

At this time, the result of calculating the so-called HCl concentration in the LD gas is shown, which is 0.24 to 1.40%, and the hydrochloric acid concentration in the waste water is 1% or less, which is extremely low. It was shown that PCB addition to this extent does not hinder the operation. The amount of gas generated by the thermal decomposition of PCB is
Since the LD gas generation amount is 35,000 Nm ³ / ch, it is 5.0% or less, which is extremely small with respect to the converter waste gas amount. The amount of cooling water used in the converter is 390 ton / ch, and as described above, the concentration of generated hydrochloric acid (HCl) can be reduced to 1% or less.

Claims (6)

[Claims] 1. A method of detoxifying a polychlorinated biphenyl (hereinafter referred to as PCB) deposit, which comprises the following steps.
(A) a step of extracting a substance containing PCB from a PCB deposit, and (b) a PCB obtained by extracting a substance containing the PCB.
A step of adding the adhered substance alone or together with the extracted substance containing PCB to a metal refining / melting furnace for refining at a high temperature of 1100 ° C. or higher to thermally decompose the PCB to render it harmless. 2. A method for detoxifying a polychlorinated biphenyl (hereinafter referred to as PCB) deposit, which comprises the following steps.
(A) a step of extracting a substance containing PCB from a PCB deposit, and (b) a PCB obtained by extracting a substance containing the PCB.
A treatment step of washing the adhering material, or drying it at 500 ° C. or higher, or after washing, and drying it at 500 ° C. or higher;
A step of adding a substance containing CB together to a metal refining / melting furnace for refining at a high temperature of 1100 ° C. or higher to thermally decompose the PCB to render it harmless. 3. A method for detoxifying a polychlorinated biphenyl (hereinafter referred to as PCB) deposit, which comprises the following steps.
(A) a step of extracting a substance containing PCB from a PCB deposit, and (b) a PCB obtained by extracting a substance containing the PCB.
A step of decomposing the deposit into a container, an iron part and a copper part, and (c) washing the disassembled container and part, or 50
A treatment step of drying at 0 ° C. or higher, or after washing and drying at 500 ° C. or higher, and (d) the treated container or part alone,
Or, together with the substance containing the extracted PCB, 11
A step of adding to a metal refining / melting furnace for refining at a high temperature of 00 ° C. or higher to thermally decompose the PCB to render it harmless. 4. A method for detoxifying a polychlorinated biphenyl (hereinafter referred to as PCB) deposit, which comprises the following steps.
(A) a step of extracting a substance containing PCB from a PCB deposit, and (b) a PCB obtained by extracting a substance containing the PCB.
A step of washing the deposits, or drying at 500 ° C. or higher, or after washing, drying at 500 ° C. or higher; and (c) decomposing the treated PCB deposits into containers, iron parts and copper parts, (D) The dried container or part is added alone or in combination with the extracted substance containing PCB to a metal refining / melting furnace for refining at a high temperature of 1100 ° C. or higher to thermally decompose the PCB, Detoxifying process. 5. A copying material containing PCB is added alone or together with other PCB deposits to a metal refining / melting furnace for refining at a high temperature of 1100 ° C. or higher to thermally decompose the PCB to render it harmless. Method. 6. The method for detoxifying polychlorinated biphenyl (hereinafter referred to as PCB) deposits according to claim 1, wherein the metal refining / melting furnace is a converter.