JP2933047B2 - Solidification treatment method of treated material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for heating and solidifying a treated material such as waste, and more particularly to a method for solidifying a treated material containing plastics by mixing a dechlorinating agent. .

[0002]

2. Description of the Related Art The amount of processed waste such as municipal garbage increases year by year, and its disposal has become a problem. Generally, municipal waste is discharged as a processed material from general households or offices and is mainly combustible. Recently, it has been considered that this flammable treated material is not simply incinerated but is effectively used as a resource, and the treated material is once solidified and reused as fuel.
However, some of the processed materials contain a large amount of chlorine in recent years, such as a wide variety of chemical substances, such as Plus Checks containing a large amount of vinyl chloride resin and chlorine bleach for paper used in offices. Due to the contaminants, simply solidifying will generate harmful gases containing chlorine components when used and burned as fuel, and if released directly into the atmosphere, it will cause air pollution, which is environmentally unfriendly. Bring results. Therefore, there is a problem in reusing as a high-efficiency and clean energy resource, and development of a technology corresponding to this problem has become an important issue.

[0003]

A problem that arises when heat-treating a processed product is the treatment of chlorine components such as chlorine and chlorine compounds contained in the processed product, and the chlorine component gasified during the heating process. Is subjected to an adsorption treatment with a filter or the like so that the chlorine component is not discharged into the atmosphere.

[0004] On the other hand, chlorine components that have not been gasified during the heating process are combined with the treated ash, resulting in treated ash containing a high concentration of chlorine components.

[0005] When the chlorine component is contained in the treated ash, it is difficult to reuse the treated ash as a resource, and the treated ash is treated solely by burying it in the ground.

Therefore, when reusing the treated ash,
Processed products are separated in advance, and only processed products that generate less chlorine components are selected and heated, and the processed ash (residue) is solidified as a fuel or in a block or the like and reused.

[0007] However, since the separation of the treated material is inefficient and the resource recovery rate is low, it is desired to establish a technique for effectively removing the chlorine component.

[0008] Further, it is also practiced to solidify the processed material (garbage) and use it as a fuel. However, at present, the flammable processed material is simply compressed and solidified. Can be achieved, but when used as a fuel, harmful gas is generated in the same manner as described above, and countermeasures are required.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for solidifying a treated product which does not generate a gas containing a chlorine component even when burned.

[0010]

As a result of numerous experiments and investigations, the inventors of the present application have mixed an appropriate amount of an alkaline substance which easily reacts with a chlorine component contained in a treated product as a dechlorinating agent into the treated product. When heat treatment is performed at a predetermined temperature, the chlorine component is reliably fixed to the residue (processed ash), and it is found that the gas generated during carbonization does not contain the chlorine component, and the residue is washed with water. It was found that the chlorine component could be effectively removed from the residue.

The present invention has been made on the basis of these findings, and solidifies a treated product by mixing a dechlorinating agent and, when burning the treated product as a fuel, does not generate a gas containing a chlorine component. Fuel was obtained.

[0012] When the processed material is solidified by utilizing the heat softening property of the plastic contained in the processed material,
This plastic is used as a binder to form a solidified fuel having a high density and a stable shape.

[0013] In the present invention, the treatment method for solidifying the treated product is a method of mixing a treated material containing plastic and a dechlorinating agent which reacts with a chlorine component, subjecting the mixture to dry distillation, and forming a product ( The residue is solidified by pressure molding. At this time, the temperature at the time of the dry distillation treatment is set to a temperature (200 ° C.) or lower at which the precipitation of the chlorine component starts, or a temperature (100 to 150 ° C.) lower than the temperature at which the dissolution of the plastic starts.

The dechlorinating agent which reacts with the chlorine component is any one of an alkaline earth metal, an alkaline earth metal compound, an alkali metal and an alkali metal compound, or a mixture thereof, and is a treated product to be treated with this. And equivalent or 5-
30% by weight, or 0.5 to the amount of chlorine component generated
Add 1.5 mol.

Further, the pressing force for producing a solid material is 100 to 1000 kg because the solidification is difficult if the pressing force is small, and the equipment becomes large if the pressing force is large.
/ Cm ² is preferred.

When the processed material solidified by the above-described processing method is used as fuel and burned, the chlorine component contained in the processed material is fixed to the processed ash by combustion as a result of the following experiment, Turned out not to be included.

In the experiment, first, the following simulated garbage which simulates standard urban garbage is prepared.

20% by weight ・ Plastic (PE, PP, PS, PVDC) 50% by weight ・ Paper (tissue, newspaper, wrapping paper, box, beverage pack) 20% by weight ・ Cloth (such as rag) 10% by weight ・ Kitchen Crushed simulated garbage, crushed simulated garbage 10kg,
1 kg of the powdery additive (Ca (OH) ₂ ) is charged into a mixer, sealed, and mixed while heating at a temperature of 150 ° C. for 10 minutes.

Next, a solidified product (pellet) is produced by a granulator under the same conditions. This pellet produced a plurality of types of pellets by changing the type of additive.

The produced pellets are Next, several of the produced pellets were placed in a closed container with an exhaust pipe, heated in an electric furnace, and the generated gas was extracted and its gas concentration (hydrogen chloride gas) ppm was measured.

The heating temperature is 200 ° C., 250 ° C., 300 ° C.
C., 350.degree. C., 400.degree. C., 500.degree. C., and 600.degree. C. were divided into seven stages, each temperature was maintained for 5 minutes, the whole was heated for 1 hour, and the gas concentration at each temperature was measured.

The gas concentration was measured using a detector tube specified in JIS-K0804.

Table 1 shows the measurement results. The measured values shown in Table 1 are average values of the measured values in 10 experiments.

[0024] In the table, * indicates that no chlorine component was detected in any of the ten experiments.

[0025]

[Table 1]

From the above results, it was found that as a dechlorinating agent, calcium silicate was reacted with a chlorine component in a low temperature range and calcium chloride was reacted with a chlorine component in a high temperature range, thereby securely fixing the chlorine component.

Of course, in the test, a large amount of plastic is mixed in the test, and in practice, calcium silicate,
Even a simple mixture of calcium hydroxide is sufficiently effective.

As described above, when a solid containing a chlorine component is subjected to a solidification treatment, the chlorine component is exhausted even if the solidified product is burned by mixing the dechlorinating agent. It became clear that mixing in the gas can be prevented.

Since the chlorine component is fixed in the treated ash after combustion, it cannot be discarded as it is, so it is necessary to perform a dechlorination treatment.

In this dechlorination treatment, as shown in FIG. 3, first, the treated ash is put into a water tank and stirred for a predetermined time (about 30 minutes) to dissolve the chlorine component in water. Next, this is dewatered and separated, and the chlorine component is removed from the treated ash, which is dried and solidified. Separated wastewater is dechlorinated separately by wastewater treatment means.

The residual chlorine component of the solidified treated ash was measured by ion chromatography and found to be 1,000 pp.
However, almost none at 5 ppm or less.

[0032]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a conceptual diagram of an embodiment of the present invention, in which reference numeral 1 denotes a treated material supply unit, 2 denotes a mixer, and 3 denotes a dechlorinating agent supply unit. Reference numeral 4 denotes a heating means for heating the processed material in the mixer 2. The heating means 4 may be any heating means such as gas heating, electric heating or combustion heating, microwave heating, induction heating, etc., but the illustrated example shows a case where induction heating is used. Electric power is supplied for induction heating.

Numeral 5 denotes a granulator having a heating means 6 on the outside and a press means comprising a pressure roller and the like inside.
Reference numeral 7 denotes a solidified product (hereinafter, referred to as a pellet) formed by the granulator 5.

The procedure for manufacturing the pellets is as follows. First, the processed material is charged into the processed material supply unit 1, the dechlorinating agent is stored in the dechlorinating agent supply unit 3, and these are supplied to the mixer 2 at a predetermined ratio. I do. In the mixing machine 2, while mixing the processed material and the dechlorinating agent,
200 ° C. or less, preferably 100 ° C.
A heat treatment (dry distillation) is performed for 10 minutes at a temperature of 150 ° C. with the outside air shut off.

Next, the opening / closing door 2b of the mixer 2 is opened, the mixture is supplied to the granulator 5, and the mixture is compression-molded by press means while heating the mixture under the same temperature conditions as described above. Then, a pellet 7 is formed. The crushing function may be added to the mixer 2.

If plastics are mixed in the processed material in the above-mentioned process, the plastics are supplied in a softened state (if they are not mixed or small, they are separately supplied from the processed material supply unit 1). As it is mixed and molded, it serves as an adhesive (binder) between the processed materials, and the produced pellets maintain a stable solid shape.

As the pressing means, for example, a feed rotary roller for feeding out the mixture and a squeezing rotary roller (which may be a heating roller) for compression molding are provided, and the pressure between the feed rotary rollers is adjusted to 100 to 1000 kg. / C
to adjust to the m ^2. If the pressure is small, solidification becomes difficult, and if it is too large, the equipment becomes large.

By performing compression molding in this manner, the volume ratio of the pellets is reduced as follows.

[0039]

[Table 2]

FIG. 2 shows another embodiment of the present invention, in which a screw feeder 10 is provided between the mixer 2 and the granulator 5. The screw feeder 10 includes a heating unit 11
And provided to further promote the mixing of the treated product and the dechlorinating agent.

Since the screw feeder 10 is also heated in the dry distillation state, it is configured to be shielded from the outside air. Accordingly, the inlet side and each have a door 10d ₁ and 10d ₂ on the outlet side, rotary driven screw 10b is provided in the cylindrical member 10a, transported while mixing the treated product and the dechlorinated agent.

The heating may be performed in either the mixer 2 or the screw feeder 10, or may be performed in both.

The dechlorinating agent to be mixed into the treated product is any one of an alkaline earth metal, an alkaline earth metal compound and an alkali metal compound, or a mixture thereof.

The above experimental investigation revealed that the chlorine component was reliably fixed by mixing a dechlorinating agent into the processed product in the mixer. (Table 1) In Table 1, the reason why calcium hydroxide reacts with a chlorine component in a high temperature region and is immobilized is that gaseous reaction with hydrogen chloride (HCl) generated at the time of thermal decomposition of the treated product causes alkali chloride to occur. ｛Ca (C
lO) ₂ .4H ₂ O.CaCl ₂ 4H ₂ O, etc., and the chlorine component is immobilized on the treated ash. The same action and effect can be expected as long as the action is the same.

Therefore, it is clear that similar results can be obtained with alkaline materials other than calcium hydroxide.

The following can be used as the alkaline material.

(A) Alkaline earth metal compounds: calcium hydroxide, calcium oxide, calcium carbonate magnesium hydroxide, magnesium oxide, magnesium carbonate barium hydroxide hydrate, barium oxide, barium carbonate strontium hydroxide, strontium carbonate dolomide ( CaCO ₃ .MgCO ₃ ) (b) Alkali metal compound: sodium hydroxide, potassium hydroxide, lithium hydroxide hydrate sodium carbonate, potassium carbonate, potassium sodium carbonate sodium carbonate hydrate, lithium carbonate The reason for the immobilization by reacting with the chlorine component in the region is that calcium silicate hydrate is porous, has a large specific surface area and contains water, and the treated product contacts and adsorbs hydrogen chloride gas generated during thermal decomposition. To fix the chlorine component in the treated ash It is because it is, as long as it functions in the same manner, it is possible to anticipate the same operation and effect.

Therefore, it is clear that similar results can be obtained with silicates other than calcium silicate.

The following can be used as the silicate.

(A) Silicate hydrate: calcium silicate hydrate, magnesium silicate hydrate, dobamonide (5CaO
_{· 6Sio 2 · 5H 2 O)} (b) silicic acid chlorides: aluminum silicate, sodium silicate and the results of experimental investigations, the amount of dechlorination agent, be added 5 to 30% by weight of the workpiece to be processed Preferably
When two types of dechlorinating agents are mixed, the mixing ratio is preferably A ≧ B when A reacts in a low-temperature region and B reacts in a high-temperature region.
In particular, it was found that the ratio of A: B was preferably set to (1.5 to 4.0): 1.

It was also found that even when a dechlorinating agent was mixed, the plastics functioned as a binder and were effectively bonded.

[0052]

As described above, according to the present invention, a dechlorinating agent is mixed with a treated material containing a plastic, and subjected to dry distillation at a temperature lower than a temperature at which a chlorine component is precipitated. (1) When molding a solid, there is no generation of a chlorine component, and the plastics soften to serve as a binder of the mixture, and are pellets having a stable shape that is easy to handle. That is, pellets suitable for carrying or transporting are obtained.

(2) Even if the pellets are burned as fuel, the chlorine component is fixed to the residue due to the presence of the dechlorinating agent, and does not mix into the exhaust gas. Is prevented.

(3) Since plastics have a strong combustion gas, the burning power (thermal power) of the processed material when burning the pellets
ramp up.

(4) For the above reasons, it can be effectively reused as a solidified fuel which is convenient to handle.

The following effects are obtained.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of an embodiment of the present invention.

FIG. 2 is a conceptual diagram of another embodiment of the present invention.

FIG. 3 is an explanatory diagram of the processing of the processing ash.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Process supply part 2 ... Mixer 3 ... Dechlorinating agent supply part 4, 6, 11 ... Heating means 5 ... Granulator 7 ... Pellet 10 ... Screw feeder

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-6-106533 (JP, A) JP-A-7-150150 (JP, A) JP-A 8-290147 (JP, A) (58) Field (Int.Cl. ⁶ , DB name) C10L 5/46 C10L 5/48

Claims (6)

(57) [Claims] Claims: 1. A treated material containing plastics is mixed with a dechlorinating agent that reacts with a chlorine component to precipitate a chlorine component.
A method for solidifying a treated product, comprising subjecting the product produced by the carbonization treatment to pressure-forming at a temperature not higher than the temperature at which dispensing starts , and press-forming the product to solidify using plastics as a binder. 2. The process according to claim 1, wherein the temperature of the dry distillation is not higher than the temperature at which the plastics are dissolved, and the temperature at which the plastics are softened, and the plastic contained in the process is used as a binder. Solidification treatment method. 3. The treated product according to claim 1, wherein the dechlorinating agent comprises any one of an alkaline earth metal, an alkaline earth metal compound, an alkali metal, and an alkali metal compound, or a mixture thereof. Solidification treatment method. Amount of 4. dechlorination agent, solidification processing method of the workpiece according to claim 1 or 3, characterized in that it is processed and the equivalent or 5 to 30 wt% being processed. 5. The method according to claim 1, wherein the amount of the dechlorinating agent added is 0.5 to 1.5 mol based on the amount of the generated chlorine component. 6. The pressure for the pressure molding is 100 to 1000.
solidification processing method of the workpiece according to claim 1, characterized in that a kg / cm ^2.