JPH11101417A - Hazardous gas generation preventing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove a hazardous gas sufficiently, by reacting a chlorinous gas and a sulfur oxide gas with a hazardous constituent treating agent so as to produce a harmless chloride and sulfite. SOLUTION: In a heat treatment furnace 2 a decomposition gas containing HCl and SOx constituents is produced, but the HCl and SOx constituents are immediately reacted with sodium hydrocarbonate so as to produce harmless sodium chloride (NaCl) and sulfite (Na2 SO3 ) so that HCl and SOx are separated from the combustion gas. Thus, detoxification of the HCl and SOx constituents and detoxification of residue are simultaneously carried out. The residue is taken out by a residue treatment means 4 and washed with water or other solutions, so as to separate and remove sodium chloride and sulfite from the residue. Thus, part of the remaining residue contains useful metals and effective recycling becomes possible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention includes harmful components such as harmful chlorine-based gas and sulfur oxide-based gas generated when a treated material such as waste is subjected to thermal treatment such as thermal decomposition. The present invention relates to a method for preventing generation of harmful gas, and more particularly to a method for preventing generation of harmful gas by reacting with harmful components such as chlorine-based gas and sulfur oxide-based gas to generate harmless chlorides and sulfites.

[0002]

2. Description of the Related Art Waste such as general waste such as municipal waste, industrial waste, shredder dust, and vinyl chloride contains a large amount of a chlorine component. Hydrogen chloride and chlorine) are generated in large quantities, causing the production of highly toxic dioxins.

[0003] In addition, incineration of waste materials such as old tires and styrene-containing wastes such as styrofoam has been performed, but waste rubber contains 5 to 10% by weight of a sulfide component. Therefore, when combusted, a large amount of sulfur oxide-based gas (SOx gas) is generated.

As a means for removing such harmful components, calcium-based alkaline substances such as lime (CaC
O ₃ ), slaked lime (Ca (OH) ₂ ) and the like are added and incinerated, or these substances are charged into a filter and SOx
It is possible to remove by passing gas,
No. 0341, JP-A-1-296007 and JP-A-59-159.
No. 12733, and the like.

The reaction formula when this lime or slaked lime is added and incinerated is as follows, and CaSO ₄ (calcium sulfate) is produced. That is, in the case of a chlorine-based gas (HCl), CaCO ₃ + 2HCl → CaCl ₂ + H ₂ O + CO ₂ Ca (OH) ₂ + 2HCl → CaCl ₂ + 2H ₂ O In the case of a sulfur oxide-based gas (SO ₂ ), CaCO ₃ → CaO + CO ₂ CaO + SO ₂ + 1 / 2O ₂ → CaSO ₄ Ca (OH) ₂ → CaO + H ₂ O CaO + SO ₂ + 1 / 2O ₂ → CaSO ₄

[0006]

When waste is incinerated, it is a chlorine component and a sulfur component contained in the material to be treated, and is decomposed and deposited in the incineration process to produce chlorine-based gas and sulfur oxide-based. Gas is generated.

[0007] These gases cause damages such as corrosion of the processing furnace and the flue, and in particular, chlorine-based gases generate highly toxic dioxins.

As a means for removing such harmful gases, if a calcium-based alkali substance is added and incinerated or removed by a bag filter or the like, a certain degree of removal is possible but not sufficient. is the current situation.

[0009] Further, when removed by a bag filter,
Since harmful substances such as dioxins are attached to the powder, post-treatment such as burying in a final treatment plant is required.

Further, CaO reacted with sulfur oxide-based gas
And the like become CaSO ₄ (calcium sulfate), which is commonly called gypsum, which solidifies when it absorbs moisture, making post-treatment extremely difficult.

[0011]

According to experiments by the inventors, when a calcium-based treating agent such as calcium carbonate is added, some effect can be expected as compared with the case where it is not added, but it is not sufficient. It has been found that a plurality of harmful substances can be effectively removed by using a sodium, potassium based alkali metal compound as a treating agent.

Accordingly, the present invention provides a heat treatment furnace in which a harmful chlorine-based gas and a harmful component treating agent that reacts with a sulfur oxide-based gas decomposed and generated from an object to be treated in a heated atmosphere are accommodated in a heat treatment furnace. The harmful component treating agent to be added at this time comprises an alkali metal compound, and reacts the harmful component treating agent with harmful chlorine-based gas and sulfur oxide-based gas to generate harmless chlorides and sulfites. And a method for preventing generation of harmful gas.

That is, according to the present invention, when an object to be treated containing a chlorine component and a sulfur component is subjected to a heat treatment, a treating agent comprising an alkali metal compound is added to the composition to thereby decompose and deposit a chlorine-based gas and a sulfur oxide. By reacting with the system gas,
Harmful components can be removed from the cracked gas and replaced with harmless salts (chlorides and sulfites) to produce harmless exhaust gas.

Therefore, the exhaust gas can be effectively used as fuel. Of course, it is also possible to perform an exhaust gas treatment for removing dust and release it to the atmosphere as it is.

The residue is also harmless, and these salts remaining in the residue can be directly dissolved in a solution such as water.

In addition, when a metal component is present in the treated product, a harmless residue is obtained, so that the metal and carbide can be recovered from the residue and reused.

The catalytic reaction in the present invention basically comprises
After the generation of the harmful gas, the harmful gas is not removed in a post-process, but is not generated.

The alkali metal compound as a harmful component treating agent is as follows: (1) A single alkali metal compound or a mixture of a plurality of alkali metal compounds.

(2) The alkali metal compound is a hydroxide,
Carbonate substance.

(3) Hydroxides and carbonates are sodium-based and potassium-based substances.

(4) The harmful component treating agent is (a) sodium bicarbonate, also known as acidic sodium carbonate, sodium bicarbonate, and sodium bicarbonate.

(B) Sodium carbonate, also called sodium carbonate, soda, soda ash, washing soda, and crystal soda.

(C) sodium sesquicarbonate, also known as sodium hydrogen dicarbonate, sodium tricarbonate, sodium sesquicarbonate, (d) natural soda, another name, trona, (e) potassium carbonate, (f) potassium hydrogen carbonate ( g) Sodium potassium carbonate (h) Sodium hydroxide (i) Potassium hydroxide A simple substance selected from the group consisting of two or more kinds are used in combination.

The atmosphere in which the harmful component treating agent and the chlorine-based gas and the sulfur oxide-based gas come into contact with each other is an atmosphere that generates a pyrolysis gas, for example, a pyrolysis atmosphere. And oxygen concentration is not specified).
It may be either a dry distillation atmosphere (intentional for steaming in a dry distillation furnace and the oxygen concentration is not specified) or a low oxygen atmosphere.

Further, the harmful component treating agent is mixed with the object to be treated, heat-treated, and brought into contact reaction.

The heated atmosphere in which the harmful component treating agent reacts with the chlorine-based gas and the sulfur oxide-based gas is 20 atmospheres.
The temperature is preferably 0 ° C. to 1000 ° C., and is determined depending on the form of the heating furnace, operating conditions (processing amount, processing time, etc.) and the state and location of the harmful component processing agent.

The form of the harmful component treating agent may be in the form of block, plate, porous, powder, solution, suspension, or a combination thereof, depending on the conditions such as the amount of treatment and the state of the facility. Arbitrarily determined.

Under the above-mentioned conditions, when the object containing the harmful component is treated with the harmful component treating agent, the harmful hydrogen chloride (HCl) is replaced with a harmless chloride according to the following reaction formula. In addition, harmful sulfur oxides (SOx) are replaced with harmless sulfites.

That is, when the harmful component is hydrogen chloride (HCl), sodium hydrogen carbonate (NaHCO ₃ ) + (HCl) → (NaCl) + (H
₂ O) + (CO ₂ ) potassium hydrogen carbonate (KHCO ₃ ) + (HCl) → (KCl) + (H ₂ O) +
(CO ₂ ) Sodium hydroxide (NaOH) + (HCl) → (NaCl) + (H ₂ O) Potassium hydroxide (KOH) + (HCl) → (KCl) + (H ₂ O) In the case of oxide (SOx), sodium hydrogen carbonate (NaHCO ₃ ) → (NaOH) + (CO ₂ ) (2NaOH) + (SO ₂ ) → (Na ₂ SO ₃ ) + (H
₂ O) Potassium hydrogen carbonate (KHCO ₃ ) → (KOH) + (CO ₂ ) (2KOH) + (SO ₂ ) → (K ₂ CO ₃ ) + (H ₂ O) Sodium hydroxide (2NaOH) + (SO ₂ ) → (Na ₂ SO ₃ ) + (2H ₂
O) Potassium hydroxide (2KOH) + (SO ₂ ) → (K ₂ SO ₃ ) + (H ₂ O) Potassium sodium carbonate (Na ₂ CO ₃ + K ₂ CO ₃ ) + (2SO ₂ ) → (Na ₂ SO)
₃ ) + (K ₂ SO ₃ ) + (2CO ₂ ), and HCl is harmless sodium chloride (NaCl, K
Cl) and SOx are harmless sulfites (Na ₂ SO ₃ , K
₂ SO ₃ ), which can make harmful components harmless.

[0030]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an explanatory view of detoxification treatment using the harmful component treating agent of the present invention. In the figure, reference numeral 1 denotes a mixing means, which is an object to be treated such as crushed waste and a harmful component treating agent. For example, sodium bicarbonate is mixed. Alternatively, a mixture obtained by other mixing means is charged.

Reference numeral 2 denotes a heat treatment furnace, which has a rotating cylindrical shape and is provided with rotary feed means for transferring the mixture while stirring the mixture, and heat-treats the mixture of the processing object and the treatment agent mixed by the mixing means 1. Reference numeral 3 denotes a heating coil as heating means of the heat treatment furnace 2.

Reference numeral 4 denotes a residue treatment means which takes out and puts the residue (processed ash) which has been heat-treated in the heat treatment furnace 2 and performs solid-liquid separation. In solid-liquid separation, the residue is washed with a solution such as water,
The generated sodium chloride or sulfite is separated and removed from the residue, taken out together with the solution to the solution discharge section 4a, and the remaining solid matter such as metal and carbide is taken out to the solid matter take-out section 4b.

Reference numeral 5 denotes an exhaust gas treatment means, which introduces a gas which has been generated in the heat treatment furnace 2 and which has been rendered harmless by reacting with the treatment agent, performing necessary treatment and collecting the gas by the gas collection means 6, or After being treated by the combustion means 7, it is discharged.

In a series of treatments, an object to be treated containing a harmful component and, for example, sodium hydrogen carbonate (N
aHCO ₃ ) is charged into the mixing means 1 to mix the two, and after sufficient mixing, is charged into the heat treatment furnace 2.

At this time, the object to be treated is crushed to be fined, or crushed while mixing. The amount of the treatment agent added is 5 to 30% by weight based on the object to be treated.

In the heat treatment in the heat treatment furnace 2, the temperature and time at which the HCl gas and the SOx gas are deposited from the object to be treated are investigated in advance, the properties of the object to be treated are grasped, and the result of this investigation is sufficiently understood. Process at a temperature and time that can be covered. (For example,
600 ° C. for 1 hour).

The time and temperature are related to the state of the heating furnace (conditions depending on the furnace such as the size and heating means), the amount of treatment, the treatment time, the treatment temperature, and the like. It needs to be done well, and it is necessary to collect and store data.

When the heat treatment is not "combustion and incineration" but "steaming and pyrolysis", the deposited harmful HCl gas and SOx gas are effectively brought into contact with the treating agent. Harmful HCl gas can be replaced with harmless sodium chloride, and SOx gas can be replaced with harmless sulfite.

Therefore, in order to maintain the reaction environment, (1) one is that the entire environment is in a stable state necessary for maintaining the reaction, for example, a stable state in a low oxygen atmosphere. That

(For example, it is necessary that a new amount of air does not enter only around the processing object during the processing, and in this case, the combustion starts around the processing object and the reaction becomes unstable. (2) Alternatively, it was found that the reaction could be maintained even by blowing fresh air so that air could be distributed throughout the inside of the pulverized processed material under the condition that the unburned state could be maintained. The result is known.

In the heat treatment furnace 2, HCl, SOx
Decomposition gas containing the components is generated, but HCl, SO
The x component reacts with the added sodium hydrogen carbonate to be harmless sodium chloride (NaCl) and sulfite (Na ₂ S).
O ₃ ) to separate harmful HCl and SOx from the decomposition gas. Thus, HCl and SOx in the decomposition gas
Detoxification of components and detoxification of residues can be performed simultaneously.

The residue is taken out to the residue treatment means 4 and washed with a solution such as water to separate and remove sodium chloride and sulfite from the residue. As a result, some of the remaining residues contain valuable metals, and can be effectively reused.

The treating agent used in the present invention is HCl gas, S
The following experimental investigation revealed that it was made harmless by reacting with Ox gas.

In the experiment, a solidified fuel (hereinafter, referred to as RDF) was used as a sample to be treated.

The RDF is a product which is solidified so as to be combustible. In a broad sense, (1) kitchen waste (remaining material such as meat, fish head, bone, eggshell, vegetables, fruits, etc., is called "compost") (2) Plastics (polyethylene, polypropylene, polystyrene, polyvinylidene chloride, etc.) (3) Papers (tissue paper, newspaper, advertising paper, bags, boxes, beverage packs, etc.) (4) ) In addition, a solidified mixture of combustible materials (fibers such as cloth, wood chips, rubber, leather, etc.).

In a narrow sense, (2), (3) and (4) which do not include the compost of (1) are referred to.

The RDF (untreated) of such a sample is crushed, several kinds of substances are selected from the alkali metal compounds according to the present invention, and a generally known and reported treated RDF is treated. A comparative experiment was performed using

It should be noted that a generally known processed RD
The sulfur component of F contains about 1.0% by weight, and the plastic RDF contains 0.29 to 0.89% by weight of a chlorine component. In addition, waste paper RDF is 0.2% by weight.
Contains a chlorine component.

In the experiment, a low-oxygen atmosphere was created in a closed vessel equipped with an exhaust pipe and having an open / close door, a sample was placed in the closed vessel, and heated in an electric furnace.
Hold at each temperature for 5 minutes at intervals of 0 ° C., open the exhaust pipe, raise the temperature, and keep the HCl gas and SO ₂ gas concentrations (pp
m) was measured.

The gas concentration was measured using a detector tube specified in JIS-KO804.

Tables 1 and 2 show the measurement results. H
The Cl gas and SO ₂ gas concentrations were measured values in ten experiments, and Comparative Examples 1 to 4 in Table 2 were the lowest values, while Example 1 in Table 1 was the lowest value.
To 7 indicate the highest values.

Note that "ND" represents "not detected",
It shows that none was detected in 10 experiments.

First, 40 g of the untreated RDF was crushed, and those obtained by adding 10 g of NaHCO ₃ as a treating agent thereto and those adding 4 g thereof were referred to as Examples 1 and 2, respectively. Examples 3 and 4 were obtained by adding ₃ g of KHCO ₃ and 3 g of Na ₂ CO ₃ · K ₂ CO ₃ as treating agents to 20 g of the crushed, respectively.
Examples 5 and 6 were obtained by adding 3 g each of NaOH and KOH as a treating agent to 20 g of RDF crushed, and further adding 10 g of NaHCO ₃ as a treating agent to 40 g of a lump that did not crush RDF. As Example 7, the HCl concentration and the SO ₂ concentration of each sample were measured. Table 1 shows the results.

[0055]

[Table 1]

Next, a conventionally known RD with a treatment agent is used.
Samples obtained by using 40 g and 20 g of the crushed F were referred to as Comparative Examples 1 and 2, respectively, and those obtained by using 40 g of the lump without crushing the RDF were referred to as Comparative Example 3, and the HCl concentration was determined for each. and it was measured SO ₂ concentration. Table 2 shows the results.

[0057]

[Table 2]

From the experimental results in Tables 1 and 2, the following is considered.

In the case of hydrogen chloride (HCl) (1) In the case of crushing, a very small amount was detected at 400 ° C. in Example 4, but was not detected in other examples, and very good results were obtained.

As can be seen from the comparison with Comparative Examples 1 and 2, there is a considerable reduction.

(2) In the case of lumps, it is slightly detected as compared with the case of crushing at 350 to 450 ° C., but it can be seen that it is considerably reduced as compared with Comparative Example 3.

In the case of sulfide gas (SO ₂ ): (1) When crushed, SO ₂ is slightly generated at 400 to 450 ° C., but very good as a whole (Example 1)
~ 6).

It can be seen that Comparative Examples 1 and 2 are considerably reduced.

(2) 350-45 in the case of a lump
Although slightly more SO ₂ is generated than when crushed at 0 ° C., it is good as a whole (Example 7).

As can be seen from the comparison with Comparative Example 3, it is considerably reduced.

According to the above experimental investigation, when treating a treated product containing a chlorine component and a sulfur component, harmful HCl
It was confirmed that HCl and SOx can be rendered harmless by adding an alkali substance (particularly an alkali metal compound) that reacts with SOx to generate harmless chlorides and sulfites.

Although the same dechlorination effect is obtained even at 600 ° C. or higher, it may be determined based on the type of equipment, time, amount of treatment, and the like.

When the treatment is carried out by adding an alkali substance, HC
The reason why the detoxification treatment of l and SOx can be performed is as follows.

A. Reaction in the case of HCl The reason why harmful hydrogen chloride is replaced with harmless chloride is apparent from the reaction as described below.

Sodium hydrogen carbonate (NaHCO ₃ ) + (HCl) → (NaCl) + (H
₂ O) + (CO ₂ ) potassium hydrogen carbonate (KHCO ₃ ) + (HCl) → (KCl) + (H ₂ O) +
(CO ₂ ) Sodium hydroxide (NaOH) + (HCl) → (NaCl) + (H ₂ O) Potassium hydroxide (KOH) + (HCl) → (KCl) + (H ₂ O) Especially in the case of hydrogen carbonate Is remarkable, this is because
First, CO ₂ is separated at a temperature lower than the temperature (250 ° C. or higher) at which hydrogen chloride (HCl) decomposes and precipitates, so that an atmosphere state in which the reaction between the remaining NaOH and KOH and the generated HCl can be performed smoothly. It is thought that it is.

That is, when the reaction state is sodium hydrogen carbonate, (NaHCO ₃ ) → (NaOH) + (CO ₂ ) (NaOH) + (HCl) → (NaCl) + (H ₂ O) Potassium hydrogen carbonate (KHCO ₃₎ ) → (KOH) + (CO ₂ ) (KOH) + (HCl) → (KCl) + (H ₂ O), and NaOH, KOH and HCl react rapidly to form harmless chlorides (NaCl, KCl). Is newly generated.

On the other hand, calcium carbonate (CaCO ₃ ) and slaked lime (Ca (OH) ₂ ) similarly produce harmless chloride (CaCl), but the reaction with Ca is not smooth.

NaCl, KCl produced as described above
Is a harmless chloride. In addition to the above substances, N
There are the following sodium-based and potassium-based substances that produce aCl and KCl, and similar effects can be obtained.

Sodium carbonate, potassium carbonate, sodium potassium carbonate, sodium carbonate hydrate, sodium sesquicarbonate, natural soda.

Next, the chlorine-based material after the treatment was confirmed.

As a result of analyzing the obtained residue, no harmful chlorine-based gas components were detected, and harmless chlorides such as sodium chloride and potassium chloride were detected. Further, the residue was stirred for 10 minutes and washed with water, so that sodium chloride and potassium chloride were dissolved in water and a carbide remained, but no harmful chlorine-based gas component was detected in the carbide.

Therefore, the harmful chlorine components are sodium chloride (NaCl) and potassium chloride (K
Cl), water (H ₂ O), and gas (CO ₂ ), do not generate hydrogen chloride that causes dioxin, and can achieve harmlessness of exhaust gas and residues.

B. In the case of SOx reaction The reason why the harmful SOx is replaced with a harmless sulfite and formed is apparent from the following reaction.

Sodium hydrogen carbonate (NaHCO ₃ ) → (NaOH) + (CO ₂ ) (2NaOH) + (SO ₂ ) → (Na ₂ SO ₃ ) + (H
₂ O) Potassium hydrogen carbonate (KHCO ₃ ) → (KOH) + (CO ₂ ) (2KOH) + (SO ₂ ) → (K ₂ SO ₃ ) + (H ₂ O) Sodium hydroxide (2NaOH) + (SO ₂ ) → Na ₂ SO ₃ ) + (2H
₂ O) potassium hydroxide _{(2KOH) + (SO 2)} → (K 2 SO 3) + (H 2 O) potassium sodium carbonate _{(Na 2 HCO 3 + K 2} CO 3) + (2SO 2) → (Na 2 S
O ₃ ) + (K ₂ SO ₃ ) + (2CO ₂ ) In particular, the effect is remarkable in the case of a hydrogen carbonate system.
First, CO ₂ is separated at a temperature lower than the temperature (300 ° C. or higher) at which the sulfurized gas (SO ₂ ) decomposes and precipitates, so that the remaining alkali metal hydroxide (NaOH, KOH) and the generated SO ₂ It is considered that the atmosphere was such that the reaction could be performed smoothly.

That is, when the reaction state is sodium hydrogen carbonate, (NaHCO ₃ ) → (NaOH) + (CO ₂ ) (2NaOH) + (SO ₂ ) → (Na ₂ SO ₃ ) + (H
₂ O) Potassium hydrogen carbonate (KHCO ₃ ) → (KOH) + (CO ₂ ) (2KOH) + (SO ₂ ) → (K ₂ SO ₃ ) + (H ₂ O), and NaOH, KOH and SO ₂ It reacts quickly to produce harmless chlorides (Na ₂ SO ₃ , K ₂ SO ₃ ). Was produced as described above, Na ₂ SO ₃ (sodium sulfite), K ₂ SO ₃ (potassium sulfite) is a harmless sulfite, in addition to the above substances, likewise, Na ₂
There are the following sodium-based and potassium-based substances that generate SO ₃ and K ₂ SO ₃ , and similar effects can be obtained.

Sodium carbonate, potassium carbonate, sodium potassium carbonate, sodium carbonate hydrate, sodium sesquicarbonate, natural soda.

Next, the sulfide after the treatment was confirmed.

As a result of analyzing the obtained residue, harmful SO was detected.
No x gas component was detected, and potassium metal salts (Na ₂ SO ₃ , K ₂ SO ₃ ), which are harmless sulfites, were detected.

Further, the residue is stirred for 10 minutes and washed with water, whereby the alkali metal salt of sulfite is easily dissolved in water, hydrolyzed to exhibit alkalinity, and (Na ₂ SO ₃ ) + (2H ₂ O) → (2NaOH) + (H ₂
SO ₃ ) (K ₂ SO ₃ ) + (2H ₂ O) → (2KOH) + (H ₂ SO
₃ ) These substances were dissolved in water and carbide remained, but no harmful SOx gas component was detected in the carbide.

Therefore, the harmful SOx components become a part of the residue, such as sodium sulfite (powder) (Na ₂ SO ₃ ), potassium sulfite (powder) (K ₂ SO ₃ ), moisture (H ₂ O),
Gas (CO ₂ ), preventing the generation of SOx gas,
It was confirmed that the detoxification of SOx gas can be realized from the decomposition gas and the residue.

Examples of the desulfurizing agent used for treating harmful components include: (1) a simple substance of an alkali metal compound or a mixture of plural kinds thereof; (2) the alkali metal compound is a substance of a hydroxide or a carbonate; Hydroxides and carbonates are sodium-based and potassium-based substances (4) Desulfurization agents are sodium hydrogen carbonate, sodium carbonate, sodium sesquicarbonate, natural soda, potassium carbonate, potassium hydrogen carbonate, sodium potassium carbonate, sodium hydroxide It has also been found that a single substance selected from the group consisting of, potassium hydroxide, and a mixture of plural kinds are suitable.

Therefore, the harmful components (chlorine-based gas and sulfur oxide-based gas) in the generated decomposition gas are contacted with the added treating agent, so that the harmful components are harmless sodium chloride (NaCl, KCl) and sulfurous acid. Salt (Na ₂ SO ₃ , K ₂
Since SO ₃ is replaced and generated, harmful components (chlorine-based gas and sulfur oxide-based gas) can be separated from the decomposed gas, and harmless decomposed gas can be obtained.

On the other hand, harmless sodium chloride and sulfite, which are part of the residue, can be effectively removed by a washing treatment with a solution such as water, and after washing, reusable metals and carbides remain, leaving harmful substances. Because it does not contain any chlorine-based gas and sulfur oxide-based gas components, it can be reused.

Further, before and after the washing treatment, each substance can be separated by an arbitrary separating means, and the separated substance can be dried and solidified to be used effectively as fuel or the like.

Although the treatment liquid after washing contains harmless chlorides, it contains almost no harmful substances, and can be subjected to wastewater treatment as required and discharged into rivers or the ocean. If necessary, dust removal and other gas treatments are performed by generally known exhaust gas treatment.

[0091]

As is evident from the results of the experiment, harmful chlorine-based gas and sulfur oxide-based gas are generated when treated materials such as waste containing chlorine and sulfur components are thermally treated. Decomposes and precipitates, but if the treating agent used in the present invention is used, it reacts with the generated harmful components and replaces and generates harmless salts, so both the detoxification of decomposition gas and the detoxification of residues are realized. it can.

In addition, the salts formed in the residue can be removed by dissolving in water or the like, and no harmful components are deposited in the removal solution, so that the waste can be treated safely.

Therefore, not only can the chlorine-based gas producing dioxins and the sulfur oxide-based gas promoting air pollution be effectively removed, but also the decomposition gas is harmless, so that it can be reused. (Turbines, boilers, etc.).

Further, since the residue can be rendered harmless, there is an extremely excellent effect that metals and carbides can be taken out from the residue and reused.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of harmful component treatment using the harmful component treating agent of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 mixing means 2 heat treatment furnace 3 heating coil 4 residue treatment means 5 exhaust gas treatment means 6 gas recovery means 7 secondary combustion means

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI B09B 3/00 B09B 3/00 303J

Claims (8)

[Claims] A harmful chlorine-based gas and a harmful component treating agent which reacts with a harmful chlorine-based gas and a sulfur oxide-based gas decomposed and generated in a heated atmosphere in a heated atmosphere are stored in a heat treatment furnace and heated. In the treatment method, the harmful component treating agent to be added is composed of an alkali metal compound, and reacts the harmful component treating agent with harmful chlorine-based gas and sulfur oxide-based gas to generate harmless chlorides and sulfites. A method for preventing generation of harmful gas, comprising preventing generation of harmful gas by using the method. 2. The method according to claim 1, wherein the alkali metal compound is a hydroxide or a carbonate. 3. The hydroxide and carbonate are sodium-based,
3. The method for preventing generation of harmful gas according to claim 2, wherein the substance is a potassium-based substance. 4. The harmful component treating agent is selected from the group consisting of sodium hydrogencarbonate, sodium carbonate, sodium sesquicarbonate, natural soda, potassium carbonate, potassium hydrogencarbonate, sodium potassium carbonate, sodium hydroxide, and potassium hydroxide, or a plurality thereof. The method for preventing generation of harmful gas according to claim 1, wherein the mixture is a mixture of species. 5. An atmosphere in which a harmful component treating agent and a chlorine-based gas and a sulfur oxide-based gas are contact-reacted with each other, wherein a thermal decomposition atmosphere,
2. The method for preventing generation of harmful gas according to claim 1, wherein the atmosphere is one of a dry distillation atmosphere and a low oxygen atmosphere. 6. The method for preventing generation of harmful gas according to claim 1, wherein the harmful component treating agent is mixed with the object to be treated and subjected to a superheat treatment to cause a contact reaction. 7. The form of the harmful component treating agent is lump, plate,
The method for preventing generation of harmful gases according to any one of claims 1 to 6, wherein the method is one of a porous material, a powder, a solution, and a suspension, or a combination thereof. 8. The heated atmosphere in which the harmful component treating agent reacts with the chlorine-based gas and the sulfur oxide-based gas is at 200 ° C.
The method for preventing generation of harmful gas according to claim 1 or 5, wherein the temperature is 1000 ° C.