JPH1060452A - Treatment of chlorine-containing plastic waste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for treating chlorine-containing plastic wastes, enabling to surely immobilize chlorine contained in the wastes, effectively utilize dry distillation residues by the use of a refiner and use the recovered dry distillation oil and the recovered dry distillation gas as fuels by adding a calcium compound to the wastes, and subsequently subjecting the mixture to two step dry distillation processes. SOLUTION: This method for treating chlorine-containing plastic wastes comprises adding a calcium compound (B) such as slaked lime or quick lime to the chlorine- containing plastic wastes (A), subjecting the mixture to a low temperature dry distillation process in a non-oxidizing atmosphere at a temperature of 300-350 deg.C, recovering the dry distillation gas, reacting the chlorine generated by the pyrolysis reaction with B and mixed metal scraps to produce the calcium. dichloride and the metal chlorides nonvolatile at the temperature, immobilizing the chlorine on the low temperature dry distillation residues (C) to separate the dry distillation gas, washing C with an alkali solution, etc., to remove chlorine, subjecting the washing residues to a high temperature dry distillation process in a non-oxidizing atmosphere at a temperature of 450-600 deg.C to recover the dry distillation gas, introducing the high temperature dry distillation residues (D) into a refiner, utilizing D as a flux in a refining process and subsequently recovering the metals except the calcium.

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 a chlorine-containing plastic waste material, and more particularly, to a method for disposing of chlorine-containing plastics such as vinyl chloride when disposing harmful chlorine compounds such as dioxins. The present invention relates to a method of performing a dry distillation treatment without generating waste, which is a method of converting a plastic component in waste into a fuel for reuse and further processing the dry distillation residue using a smelting furnace. This is an effective treatment method for not only shredder dust in which metal is mixed but also plastic waste in which metal waste is not mixed, such as vinyl chloride coated waste.

[0002]

2. Description of the Related Art In recent years, urban garbage and industrial waste have rapidly increased,
Landfill and incineration have become social issues. Especially,
Shredder dust and household electrical waste generated by the crushing of automobile waste are increasing rapidly, and countermeasures are urgently required. This shredder dust is a mixture of plastic waste such as vinyl chloride as a coating material for wiring and metal scrap, and most of the shredder dust is currently landfilled. On the other hand, for plastic waste contained in industrial waste, from the viewpoint of resource recycling,
The use of fuel (solid fuel, oil, gasification) has been attempted, and a typical method is known in which plastic waste and rubber waste are carbonized to recover oil and gas (Japanese Patent Application Laid-Open (JP-A) no. No. 48-67, No. 49-90773, No. 50-4168, No. 50
-85573).

However, when chlorine-containing plastics such as vinyl chloride are directly thermally decomposed, chlorine generated during the pyrolysis becomes hydrogen chloride gas, which causes corrosion of the apparatus, and hydrocarbons generated by the thermal decomposition of the plastics. Since it is mixed with gas, there is a problem in recovering and using it as fuel. Further, the method of incineration in the presence of air has a problem that harmful chlorine compounds such as dioxin are generated. In view of the above, chlorine-containing plastic waste is subjected to low-temperature dry distillation by adding high-temperature steam, separating chlorine as hydrogen chloride, and then incineration (Japanese Patent Laid-Open No.
-60466) or by adding iron or iron oxide to vinyl chloride resin and subjecting it to heat treatment to react chlorine with iron.
After the valence of iron chloride FeCl _3, a method of the iron chloride be separated gasified (Japanese Patent Publication No. 50-32264) are known.

[0004]

However, the former method does not solve the problem of corrosion due to hydrogen chloride, and the latter method converts the chlorine into iron (III) chloride, which has high sublimability, so that it can be heated at a low heating temperature. Decomposition treatment is the same as the conventional method in that chlorine is gasified and separated, and a step of separating product gas and iron chloride after thermal decomposition is necessary, so the treatment process is complicated. The efficiency of fuel conversion and recycling is low. In addition, in any of the above methods, shredder dust containing a large amount of metal dust remains in a large amount as incinerated ash without being collected, and this incinerated ash is solidified with cement to prevent elution of heavy metals and generation of dust. Slag must be landfilled or melted into a stable slag, leaving problems in recycling.

[0005] In addition, a treatment method for steaming vinyl chloride-containing dust in a non-oxidizing atmosphere (JP-A-7-80433)
), And a treatment method in which an alkali or alkaline earth salt is added to vinyl chloride-containing dust and steamed in a non-oxidizing atmosphere (Japanese Patent Application Laid-Open No. 7-150150). According to these methods, chlorine produced by the thermal decomposition of vinyl chloride reacts with mixed metal scraps or alkaline earth compounds to form chlorides, which has the advantage of being fixed in the carbonization residue,
Since all of the carbonization temperatures are single-stage carbonization at 350 to 500 ° C., the desorption of chlorine and the generation of hydrocarbon gas due to the thermal decomposition of vinyl chloride proceed simultaneously, and chlorine is mixed into the hydrocarbon gas. There is a problem of insufficient fixation.

An object of the present invention is to provide a processing method for solving the above-mentioned problems in a conventional method for processing chlorine-containing plastic waste material.

[0007]

According to the present invention, by performing two-stage carbonization of low-temperature carbonization at 350 ° C. or less and high-temperature carbonization at 450 ° C. or more, fixation of chlorine released from plastic by thermal decomposition and recovery of hydrocarbon gas are performed. By adding a calcium compound, chlorine can be fixed and carbonized even for plastic waste that does not contain metal scraps, such as vinyl chloride-coated waste, and this dry distillation can be performed. The residue is easily used in a smelting furnace. Further, the recovered carbonized oil and carbonized gas can be used as fuel.

That is, according to the present invention, there is provided a method for treating chlorine-containing plastic waste having the following constitution. (1) A calcium compound is added to chlorine-containing plastic waste material, and low-temperature carbonization is performed at a temperature of 300 to 350 ° C. in a non-oxidizing atmosphere to recover a carbonized gas, while chlorine generated by thermal decomposition of the chlorine-containing plastic waste material is removed. The chlorine is fixed in the low-temperature carbonization residue by reacting with the calcium compound and the mixed metal dust to generate calcium chloride and metal chloride which are not volatilized at the carbonization temperature, and separated from the carbonization gas, thereby removing the chlorine. After washing and dechlorination, the washing residue is removed in a non-oxidizing atmosphere at 450-6.
While high-temperature carbonization at a temperature of 00 ° C. recovers carbonization gas,
A method for treating chlorine-containing plastic waste material, comprising introducing a high-temperature carbonized residue into a smelting furnace, using the high-temperature carbonized residue as a flux in the smelting process, and collecting metals other than calcium. (2) The treatment method according to the above (1), wherein slaked lime, quicklime or calcium carbonate is used as the calcium compound. (3) Chlorine-containing plastic waste is vinyl chloride-coated waste,
The treatment method according to the above (1) or (2), which is household waste material. (4) The treatment method according to any one of (1) to (3), wherein the chlorine-containing plastic waste material is shredder dust, and the low-temperature carbonization is performed in the presence of a mixture of shredder dust metal dust and a calcium compound. (5) The above-mentioned (1) to (4), wherein the low-temperature distillation residue is washed with alkali and the metal chloride in the low-temperature distillation residue is recovered as a hydroxide.
The processing method according to any one of the above. (6) The treatment method according to any one of (1) to (5) above, wherein the carbide is separated from the high-temperature dry distillation residue and the high-temperature dry distillation residue is introduced into a smelting furnace. (7) The treatment method according to any one of (1) to (5) above, wherein the high-temperature dry distillation residue is pulverized, magnetically separated to collect and collect iron waste, and then introduced into a smelting furnace.

The treatment method of the present invention comprises the steps of (a) adding a calcium compound to chlorine-containing plastic waste material, (b) low-temperature carbonizing at a temperature of 300 to 350 ° C. in a non-oxidizing atmosphere, and removing chlorine by thermal decomposition. Is reacted in the calcium compound and fixed in the low-temperature distillation residue, and (c) while collecting the low-temperature distillation gas, washing and dechlorinating the low-temperature distillation residue,
(D) The cleaning residue is subjected to 450-600 in a non-oxidizing atmosphere.
High-temperature carbonization at a temperature of ° C., and (e) a method comprising separating and recovering a carbide from a high-temperature carbonization residue while recovering the high-temperature carbonized gas. This is a method in which the carbonization residue is introduced into a smelting furnace, and in the smelting process, the calcium content contained in the high-temperature carbonization residue is used as a flux and metals other than calcium are recovered.

Hereinafter, each processing step will be described in detail. (I) Chlorine-containing plastic waste material In the present invention, the chlorine-containing plastic waste material refers to a waste mainly composed of a chlorine-containing resin represented by vinyl chloride or the like. Vinyl chloride is used in large quantities as a covering material for electric wires, and theoretically contains about 56% by weight (hereinafter referred to as "%") of chlorine, and its combustion with other polyolefin resins and polystyrene resins. The thermal decomposition behavior is different, and the thermal decomposition proceeds at a relatively low temperature (about 200 ° C. or higher) and chlorine is released. A representative chlorine-containing plastic waste is shredder dust. Shredder dust generally contains 10 to 30% by weight of metal dust, but the remainder is mainly a resin component such as vinyl chloride. In addition to these, there are vinyl chloride-coated waste materials such as wire scraps, household electrical appliance waste materials, and chlorine-containing plastic waste materials contained in municipal waste discharged from ordinary households.

(II) Addition of Calcium Compound In the present treatment method, when the chlorine-containing plastic waste material is thermally decomposed, the chlorine-containing plastic waste material is added to the chlorine-containing plastic waste material in order to avoid gasification. And dry-distilled at a low temperature of 300 to 350 ° C. in a non-oxidizing atmosphere. The chlorine released from the plastic by the thermal decomposition reacts with the added calcium compound to form calcium chloride, and the calcium chloride does not evaporate at the above-mentioned carbonization temperature and is fixed in the carbonization residue. Therefore, almost no chlorine gas or hydrogen chloride gas is generated during thermal decomposition. On the other hand, when the coating waste material containing vinyl chloride as a main component, such as wire scraps, is carbonized in a nitrogen gas atmosphere without a calcium compound, more than 80% of the chlorine contained by 300 ° C is converted to hydrogen chloride gas or chlorine gas. Vaporize.

[0012] The calcium compound may be added to the mixture of metal scraps. A typical chlorine-containing plastic waste containing metal scrap is shredder dust. Shredder dust usually contains 10 to 30% by weight of metal scraps, which can be further treated with a calcium compound.

The calcium compound used in the present invention is, for example, slaked lime, quicklime or calcium carbonate. The addition amount of the calcium compound is theoretically sufficient as long as it is sufficient to convert the total amount of chlorine released from the plastic into metal chloride and immobilize it, but it is excessive than the reaction equivalent in terms of reaction efficiency and the like. Is preferred. In addition, when added to a mixture of metal scraps, the total amount of the metal scraps and the calcium compound may be an amount sufficient to immobilize the chlorine, but is excessive in terms of reaction efficiency and the like. Is preferred.

(III) Low-Temperature Dry Distillation The treatment method of the present invention is characterized in that a chlorine-containing plastic waste material is mixed with a calcium compound in a non-oxidizing atmosphere at 300 to 35%.
Low-temperature dry distillation at a heating temperature of 0 ° C. In this low-temperature carbonization, the chlorine-containing plastic waste material is thermally decomposed, and the elimination of chlorine mainly proceeds. In the heating range of about 300 ° C or less, vinyl chloride is released along with the generation of hydrocarbon gas due to the thermal decomposition of plastics. At about 250 ° C, the weight is reduced by less than 40%, and the weight decreases with increasing heating temperature. And the weight loss reaches about 60% at about 300 ° C. In a temperature range of about 300 to 350 ° C., most of the chlorine contained in the plastic component is released at this stage, so that the weight loss amount remains as small as about 60%. When the heating temperature rises to a temperature range exceeding about 350 ° C., thermal decomposition of the hydrocarbon group itself proceeds and the weight decreases again, the amount of generated hydrocarbon gas increases, and at 600 ° C., about 95% of the weight is reduced. Lost.

The dry distillation treatment of the present invention corresponds to the progress of the above-mentioned pyrolysis, and the temperature of 300 to 350 ° C. where the release of chlorine by the pyrolysis of plastics proceeds to the maximum while the generation of hydrocarbon gas is small. Perform low-temperature carbonization in the range, remove most of the contained chlorine, react with calcium compounds and metal scraps, and generate calcium chloride and metal chloride that do not volatilize at low-temperature carbonization temperatures and fix them in the carbonization residue . As mentioned earlier, 300-35
The temperature range of 0 ° C is a temperature range in which almost all of the chlorine contained is released by this stage, and the thermal decomposition of hydrocarbon compounds in plastics does not proceed so much. Therefore, the released chlorine is separated from the carbonized gas to form a carbonized residue. It is convenient to fix.
If the carbonization temperature is lower than 300 ° C., the desorption of chlorine is insufficient, and if it exceeds 350 ° C., the amount of generated hydrocarbon gas increases rapidly, which is not preferable.

[0016] The carbonization time is a time sufficient for chlorine to be almost completely eliminated by the thermal decomposition of the plastic. Although it depends on the type and temperature of the waste material, when about 200 g of shredder dust is carbonized at 300 ° C., it takes about one and a half hours.

Dry distillation is performed in a non-oxidizing atmosphere in which an inert gas such as nitrogen is introduced and air is exhausted. Here, the non-oxidizing atmosphere means that the oxygen concentration is 16 vol% or less, preferably the oxygen concentration is 4 vol% or less. Dry distillation in the air (oxidizing atmosphere) is not preferable because iron scraps and the like mixed in shredder dust and the like are oxidized during dry distillation to form volatile chlorides having a high oxidation number. For example, when iron is carbonized in the air, it reacts with chlorine released from plastic and reacts with it.
This produces monovalent iron chloride (FeCl ₃ ). This iron chloride (FeCl ₃ ) has a boiling point of about 317 ° C., and the boiling point of divalent iron chloride (FeCl ₂ ) (about 1 ° C.).
023 ° C.), so that it is vaporized at the time of dry distillation, and chlorine is not fixed in the dry distillation residue.

(IV) Recovery of dry distillation gas, washing of dry distillation residue By low-temperature dry distillation, almost all of chlorine contained in plastic is eliminated, and about 10% of plastic is pyrolyzed and gasified. This carbonization gas is led to a condenser,
The condensed liquid is recovered by cooling and condensing, and the dried liquid is separated into oil and water by centrifugation or the like. In addition, an uncondensed gas component is introduced into an alkaline solution, and a very small amount of chlorine component remaining in the gas is collected and separated by alkali washing, followed by recovery. This carbonization gas is mainly hydrocarbon and hydrogen and can be reused as fuel gas.

After the low-temperature carbonization, undecomposed plastics, unreacted calcium compounds, metal scraps and the like remain as carbonization residues in addition to metal chlorides and calcium chloride produced by reacting with chlorine. Most of the calcium chloride and metal chloride contained in the low-temperature dry distillation residue are water-soluble, so that the residue is washed to dissolve the metal chloride and dechlorinated. Since the low-temperature dry distillation residue is in a lump, it is preferable to pulverize the residue before washing to enhance the chlorine elution effect. Washing may be water washing,
Alternatively, alkali washing with caustic soda, lime, or the like may be used. By washing with caustic soda or lime,
The washing solution is neutralized, and the metal ions leached from the residue precipitate as hydroxides, which can be separated and collected. In this case, the amount of alkali in the cleaning solution is such that the leached metal content falls within a pH range where hydroxide precipitation occurs.
The optimum pH range varies depending on the type of metal and the like, and the amount of alkali may be determined according to each metal type and the like. In addition,
The metal chloride may be separated and recovered by a method such as electrodialysis or an ion exchange resin, or a method of boiling and crystallization of the washing solution.

If the pH value of the washing wastewater is out of the regulation value of the wastewater, the pH of the wastewater is adjusted again after collecting the metal hydroxide to fall within the regulation value of the wastewater. Specifically, the pH of wastewater is 5.8 to 8.
Since it is regulated to the range of 6, when the value deviates from the regulated value, the metal hydroxide is recovered and then the pH is adjusted again to adjust the pH to the above range.

(V) High-temperature dry distillation After washing the low- temperature dry distillation residue, the washed residue is subjected to high-temperature dry distillation.
Most of the undecomposed plastic contained in the washing residue by high-temperature dry distillation is thermally decomposed and gasified. The temperature of the high-temperature carbonization is suitably from 450 to 600 ° C. If the temperature is lower than 450 ° C, the thermal decomposition of the plastic is insufficient, and even if the temperature exceeds 600 ° C, the efficiency of the thermal decomposition does not substantially change.
High-temperature carbonization is performed in a non-oxidizing atmosphere similarly to low-temperature carbonization.
Since the metal chloride is washed and removed from the washing residue, chlorine gas and hydrogen chloride gas are scarcely contained in the high-temperature carbonized gas, and most of the carbonized gas is hydrogen and hydrocarbons. This is led to a cooling unit where it is condensed, and the dry distillate is recovered. Examples of gas components (wt%) after the recovery of the dry distillation liquid are shown below. H ₂ : 51%, CH ₄ : 17%, CO ₂ : 0.05%, CO: 7.6%, C ₂ H ₄ : 0.6%, C ₂ H ₆ : 2.6%, C ₃ H ₈ : 1.1%, nC ₄ H ₁₀ : 1.0% Water is removed from the above-mentioned dry distillation liquid by centrifugation or the like as in the case of low-temperature dry distillation gas, and the oil is recovered. The recovered carbonized gas and oil can be reused as fuel. On the other hand, the uncondensed gas component is led to an alkaline solution, and the chlorine component remaining in the gas in a very small amount by the alkali washing is collected and separated, followed by recovery.

In high-temperature dry distillation, most of the undecomposed plastic is gasified and separated and recovered, and unreacted metal scraps, calcium compounds and carbides generated by thermal decomposition of the plastic remain as residues. Most of the chlorine is removed by low-temperature carbonization, so the amount of chlorine remaining in the high-temperature carbonization residue is very small.However, if necessary, the high-temperature carbonization residue is washed to remove a small amount of residual metal chlorides, and then dried and carbonized. Collect. The recovery of the carbide can be performed by removing iron by magnetic separation, using specific gravity separation, heavy liquid separation, or a method utilizing a difference in shape or particle size. The residue may be washed with water or with alkali.

(IV) Treatment by Smelting Furnace Since unreacted calcium compounds remain in the high-temperature dry distillation residue, they can be introduced into a smelting furnace and used as flux. In addition, unreacted metal scraps remain in the high-temperature carbonized residue together with the calcium compound in those obtained by dry-distilling shredder dust and the like, and the high-temperature carbonized residue is introduced into the smelting furnace and contained in the residue. The calcium compound can be used as a flux and the mixed metal can be recovered in the smelting mat.
In addition, when chlorine-containing plastic waste such as shredder dust is directly put into the smelting furnace without going through the above-mentioned dry distillation process,
As described above, chlorine gas and hydrogen chloride gas generated by decomposition of plastics cause corrosion of equipment such as a smelting furnace and a flue, and also impair the working environment. Such a problem does not occur if the residue that has been subjected to the dry distillation step in advance is introduced into the smelting step as in the present treatment method.

The type of smelting furnace into which the carbonization residue is charged is not limited, and various smelting furnaces used in a smelting process or a refining process for dissolving coarse ore ore, etc. A furnace, a reduction furnace, a reverberatory furnace, a converter, a refining furnace, or a melting furnace, a separation furnace, or a copper making furnace in continuous copper smelting can be used, and these are selected according to the properties of the dry distillation residue. The iron chips contained in the high-temperature residue are washed, dried and pulverized, and if necessary, separated and collected by magnetic separation or the like. This scrap iron can be reused as scrap. Further, the carbonized gas, carbonized oil or solid carbide collected in the low-temperature and high-temperature carbonization can be used as fuel for the smelting furnace.

As an example, a processing method utilizing a copper smelting process will be described. Copper concentrate is melted in a reverberatory furnace to produce siliceous slag and copper sulfide mat, which are led to a converter. Air is blown into the molten mat to oxidize the sulfur content of copper sulfide to blister copper and oxidize the iron content in the mat to drive it out to slag. The slag is returned to the reverberatory furnace, while the blister copper is sent to the refining furnace, where the impurities in the blister copper are oxidized and volatilized, or slag is removed, and then reduced to obtain purified copper. The residue generated by the high-temperature carbonization of the present invention is charged into the above-mentioned reverberatory furnace or converter depending on the properties thereof, and is melted together with copper concentrate and silicate ore. The iron and calcium contained in this high-temperature distillation residue are oxidized into slag,
This calcium plays a role in reducing the viscosity of the slag. Therefore, the high-temperature dry distillation residue can be used as a flux and can be used as a part of the flux in a general smelting furnace. Further, the copper and precious metal components contained in the high-temperature dry distillation residue are melted in the mat, contained in the blister copper, sent to a refining furnace, and finally recovered through an electrolytic process and the like. Lead, zinc, and the like contained in the residue are oxidized in a reverberatory furnace or converter to become smoke ash, which is recovered from exhaust gas. The slag separated in the converter is returned to the reverberatory furnace and reused, as well as used as a raw material for cement and aggregate.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention are shown below together with comparative examples. Note that this example does not limit the scope of the present invention. Example 1 A state in which 47 g of quicklime was added to 100 g of electric wire covering waste mainly composed of vinyl chloride, and the mixture was placed in a carbonization apparatus to shut off air.
(Oxygen concentration 1% or less), heat to 300 ° C and dry distillation for 1 hour
(Low-temperature carbonization), and 12 g of carbonized gas was recovered. The residue of this low-temperature carbonization was 135 g, and no chlorine was detected in the carbonization gas. Next, the residue was washed with water, then charged into the above-mentioned distillation apparatus, and heated to 550 ° C. in the same manner with the air being cut off (oxygen concentration 1% or less), and carbonized for 1 hour (high-temperature carbonization). 39 g of gas was recovered. The residue of this high-temperature carbonization was 36 g, and no chlorine was detected in the carbonization gas. 35 g of carbonized oil was obtained from the carbonized gas collected by the low-temperature and high-temperature carbonization. Further, the high-temperature carbonized residue was placed in a water tank to separate and remove the suspended carbides. Then, 28 g of the high-temperature carbonized residue was placed in a melting test furnace together with 205 g of copper concentrate and 20 g of silicate ore, and heated to 1350 ° C. to be melted.
26 g of slag and 117 g of mat were obtained. The viscosity of this slag was 4 poise, and the slag had low viscosity and good properties. The results are shown in Table 1.

Comparative Examples 1, 2, and 3 The vinyl chloride-coated waste was subjected to dry distillation in the same manner as in Example 1 except that quicklime was not added. The results are shown in Table 1 as Comparative Example 1. In this example, chlorine gas and hydrogen chloride gas were mixed in the carbonization gas in both the low-temperature and high-temperature carbonization, and chlorine could not be fixed to the carbonization residue.
Further, except that the low-temperature carbonization was omitted and the high-temperature carbonization at 500 ° C. (single-stage carbonization) was performed, the vinyl chloride-coated waste material was carbonized in the same manner as in Example 1. Table 1 shows the results as Comparative Example 2.
It was shown to. In this example, chlorine was fixed to the carbonization residue, but the concentrations of chlorine gas and hydrogen chloride gas in the carbonization gas were high, and the fixing of chlorine to the carbonization residue was insufficient. As described above, in Comparative Examples 1 and 2, since the chlorine concentration in the carbonized gas was high, the recovery of the carbonized oil and the fuel gas from the carbonized gas was not sufficient, and the utilization as a heat source in the smelting process was insufficient. On the other hand, as Comparative Example 3, in the same smelting process as in Example 1, copper concentrate was melted under the same conditions except that the high-temperature dry distillation residue obtained in Example 1 was not added. As a result, 104 g of mat and 112 g of slag were produced, and the viscosity of the slag was 6 pois.
e and highly viscous.

Examples 2, 3, 4 Shredder dust (plastic amount 30%, metal scrap amount 1)
3%) 100g, 4g quicklime, 5g slaked lime,
6 g of calcium carbonate was added, and the carbonization temperature was adjusted to 300 to 35.
The dry distillation was performed under the same conditions as in Example 1 except that the temperature was 0 ° C (low temperature dry distillation) and 450 to 600 ° C (high temperature dry distillation). The results are shown in Table 1. This high-temperature dry distillation residue (Fe: 9wt%, Cu: 5wt
%, Ca: 8 wt%) was melted together with copper concentrate and silicate ore under the same conditions as in Example 1 to obtain 142 g of slag and 132 g of mat. The composition of this slag is C
aO: 5.4wt%, FeO: 37.2wt %, SiO 2: a 20.2wt%, were those composed mainly of iron and calcium contained in the high-temperature carbonization residue. Further, it was confirmed that metals other than iron and calcium contained in the high-temperature dry distillation residue were hardly contained in the slag, and were recovered in the mat. The viscosity of this slag was 3 poise, and the slag had good properties with low viscosity.

Example 5 (1) Dry distillation process Shredder dust having the composition shown in Table 2 was treated at a rate of 2 tons / hour and 5 w
After adding t% quicklime, the mixture was heated to 350 ° C. and continuously subjected to low-temperature carbonization. The resulting carbonized residue was washed with 5 m ³ of water per hour, dehydrated, dried on the sun, and dried in the above-mentioned carbonization furnace. And heated to 550 ° C. to continuously perform high-temperature dry distillation. The carbonized gas from the low-temperature and high-temperature carbonization was cooled and condensed to recover the carbonized liquid. Further, the uncondensed gas was recovered by washing it by introducing it into an alkaline solution. The carbonized oil was separated into oil and water by centrifugation, and the carbonized oil was recovered. The calorific value of the recovered carbonized oil was 8,800 kcal / kg, and the calorific value of the uncondensed gas was 1,100 kcal / kg. The results are shown in Table 1. Table 2 shows the composition of the washing residue after high-temperature distillation. (2) Smelting process 140 kg of the washing residue from the high-temperature dry distillation process is sent to the copper smelting process, which is added to a raw material consisting of 800 kg of copper concentrate and 80 kg of silicate ore, introduced into a melting furnace, and heated at 1350 ° C. for 1 hour. ,
470 kg of copper mat and 509 kg of slag were obtained. Table 2 also shows the composition of the raw material ore composed of copper concentrate and silicate ore and the composition of slag and mat. As shown in the results, when a high-temperature dry distillation residue in an amount of 1/3 with respect to the copper mat was added,
The amount of copper mat and slag increases in proportion to the amount of residue added, so that the metal components and non-metal components in the residue are absorbed by the copper mat and slag, respectively, and the viscosity of the slag decreases, resulting in good properties. It was confirmed that.

[0030]

[Table 1]

[0031]

[Table 2]

[0032]

According to the treatment method of the present invention, a calcium compound is added to a chlorine-containing plastic waste material and subjected to two-stage low-temperature and high-temperature carbonization treatment, whereby chlorine generated by thermal decomposition of the plastic is reacted with calcium to form a carbonized residue. By effectively fixing, the problem of chlorine damage caused by the thermal decomposition of plastics can be solved, and the high-temperature carbonized residue can be used as a substitute for flux in the smelting process, and metal can be recovered at low cost. it can. Further, heat recovery can be achieved by utilizing a carbonized gas, a carbonized gas and a carbonized oil generated by the thermal decomposition of plastic as a fuel. In addition, since slag generated in the smelting process can be used as a raw material for cement or the like, the final waste that must be landfilled as in the related art does not occur, and the problem of shredder dust disposal can be completely solved.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akihiko Sakonooka 1-297 Kitabukuro-cho, Omiya-shi, Saitama Mitsubishi Materials Research Institute (72) Inventor Hitoshi Takeuchi 1-3-25 Koishikawa, Bunkyo-ku, Tokyo Earth Mitsubishi Materials Corporation Earth Business Center

Claims (7)

[Claims] 1. A calcium compound is added to chlorine-containing plastic waste material, and low-temperature carbonization is performed at a temperature of 300 to 350 ° C. in a non-oxidizing atmosphere to recover a carbonized gas, while the chlorine-containing plastic waste material is thermally decomposed. The chlorine is reacted with the calcium compound and the mixed metal dust to generate calcium chloride and metal chloride which do not volatilize at the carbonization temperature, thereby fixing the chlorine in a low-temperature carbonization residue and separating the chlorine from the carbonization gas, After washing and dechlorination of the carbonized residue, the washed residue is treated under a non-oxidizing atmosphere for 4 hours.
While high-temperature carbonization is performed at a temperature of 50 to 600 ° C. to collect the carbonization gas, the high-temperature carbonization residue is introduced into a smelting furnace, and the high-temperature carbonization residue is used as a flux in the smelting process and metals other than calcium are recovered. A method for treating chlorine-containing plastic waste material. 2. The treatment method according to claim 1, wherein slaked lime, quicklime or calcium carbonate is used as the calcium compound. 3. The method according to claim 1, wherein the chlorine-containing plastic waste material is a vinyl chloride-coated waste material or a household electrical appliance waste material. 4. The treatment method according to claim 1, wherein the chlorine-containing plastic waste material is shredder dust, and the low-temperature dry distillation is performed in the presence of a mixture of shredder dust metal dust and a calcium compound. 5. The treatment method according to claim 1, wherein the low-temperature dry distillation residue is washed with an alkali, and the metal chloride in the low-temperature dry distillation residue is recovered as a hydroxide. 6. The processing method according to claim 1, wherein the high-temperature carbonized residue is introduced into a smelting furnace after separating the carbide from the high-temperature carbonized residue. 7. The processing method according to claim 1, wherein the high-temperature dry distillation residue is pulverized, magnetically separated to collect and collect iron waste, and then introduced into a smelting furnace.