JP4438329B2 - Method for treating waste containing organic matter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for treating waste containing organic matter, which can use the waste containing organic matter as a part of a cement raw material.
[0002]
[Prior art]
Most of the general waste and industrial waste are landfilled at the final disposal site, or landfilled at the final disposal site after incineration.
[0003]
For example, soil mixed with oil such as the site of an oil refinery factory, soil contaminated with organic matter such as trichlorethylene used for cleaning, sludge generated at sewage treatment plants, incineration ash containing dioxins, etc. , Debris, brick scraps, concrete blocks, facility interior materials, etc., soil contaminated with dioxins around the waste incineration facility, gypsum board, Fibers such as glass wool, pulp sludge, and wallpaper, plastic molded articles that are likely to generate dioxins upon combustion, and organochlorine waste such as chemical fibers have been disposed of in the same manner.
[0004]
However, in recent years, with regard to incineration plants and final disposal sites, due to the strict consideration of the environment, it has become difficult to secure new incineration plants and final disposal sites. Yes.
[0005]
Therefore, it is an important social issue to recycle waste containing organic substances without adversely affecting the environment.
For this reason, methods for effectively utilizing waste containing organic substances as part of cement raw materials have been promoted.
[0006]
In this case, waste containing organic matter is fed into a raw material crushing and drying process in a cement manufacturing facility as a part of cement raw material, and is pulverized while being heated and dried by exhaust gas introduced from the rotary kiln, and then, the rotary kiln is passed through a preheater. To be cement clinker in the rotary kiln.
[0007]
[Problems to be solved by the invention]
However, in the method for treating waste containing organic matter, the organic matter such as oil evaporates by heating with the exhaust gas, adheres to the electrode of the electric dust collector for purifying the exhaust gas, and significantly reduces the performance of the dust collector. Or may generate odors. In addition, even when the above-described concrete block, fibers, or the like are crushed, the dust adheres to the electric dust collector, and the dust collection performance is significantly reduced.
[0008]
However, when waste containing organic matter is thrown into the rotary kiln without passing through the above raw material drying and grinding step, these wastes include lumps, plates, etc. May adversely affect clinker quality.
[0009]
The present invention has been made in view of the above circumstances, and is effectively utilized as a resource for producing a high-quality cement clinker without adversely affecting the environment and without reducing the performance of the electrostatic precipitator. An object of the present invention is to provide a method for treating waste containing organic matter.
[0010]
[Means for Solving the Problems]
According to the first aspect of the present invention, there is provided a method for treating waste containing an organic substance. When a cement raw material is pulverized by a dry mill and preheated in a preheater and then put into a rotary kiln for cement firing to produce a cement clinker, the organic substance is contained. Add a solvent and lime waste to give fluidity to the waste , pulverize it with a wet mill, solid-liquid separate , put the cake obtained into the kiln bottom of the rotary kiln, and contain the organic matter The organic component of the waste is consumed as a part of the fuel, and the waste containing the organic substance is disposed by using the remainder as a part of the cement raw material . The invention described in claim 2 is characterized in that, in the invention described in claim 1, the solid-liquid separated liquid is reused as a solvent.
[0011]
Here, the waste containing organic matter includes, for example, soil containing oil such as gasoline, lubricating oil and hydraulic oil, soil containing trichlorethylene as a cleaning agent, sludge generated in a sewage treatment plant, dioxin It is contaminated with debris, brick waste, concrete lump, facility interior materials, etc. generated from the demolition of facilities that generate dioxins such as waste incineration ash, etc. Soil, etc., fibers such as plasterboard, glass wool, pulp sludge, wallpaper, plastic molded products that may generate dioxins when burned, organic chlorine-based waste such as chemical fibers, etc. It is done.
[0012]
When these wastes are pulverized with a wet mill, the temperature does not increase due to pulverization. For example, even if the waste contains low-boiling organic substances such as trichlorethylene, the waste is removed while preventing the organic substances from vaporizing. And can be pulverized and mixed.
[0013]
By putting the above pulverized waste into the cement firing process, the organic matter can be consumed as part of the fuel, and the soil, brick waste, concrete lump, etc. are part of the cement raw material (clay, limestone, etc. As a part of the above, it can be used for the production of cement clinker. Accordingly, it is possible to save fuel costs for cement firing and save cement raw materials such as clay and limestone. In addition, by crushing the waste as described above, it is possible to finely pulverize the scrap (such as stones) contained in the waste, so that the cement clinker can be maintained in a high quality state.
[0014]
In addition, the waste pulverized material is directly input to the cement firing process via a different route from the normal cement raw material, and is not passed through the raw material dry pulverization process using the exhaust gas of the rotary kiln. There is no possibility that the components will evaporate and adhere to the electrode of the electrostatic precipitator for purifying the exhaust gas, so that the performance of the electrostatic precipitator is remarkably deteriorated or odor is generated. Moreover, it can also prevent that the dust produced by grind | pulverizing a concrete lump, fibers, etc. adheres to the electrode of an electrostatic precipitator, and reduces the performance of the said electrostatic precipitator.
[0015]
In addition, since the pulverized waste is input to the cement firing process by a different route from the normal cement raw material as described above, the above-mentioned wet mill does not exist in the normal cement manufacturing facility. It will be installed as one or separate.
[0016]
Further, slurry waste is ground and mixed with a solvent by wet milling is introduced from the solids cake by solid-liquid separation. In this case, as in the invention described in claim 2, the separated liquid can be reused as a solvent. In addition, when the organic substance is oil and water is added as a solvent, oil / water separation is performed, and oil can be used as a fuel and water can be reused as a solvent.
[0017]
In addition, it is preferable that large lump waste such as brick scrap and concrete lump is crushed by a crusher and then put into a wet mill.
Furthermore, before putting into a wet mill, waste containing organic matter is stirred and mixed with a solvent, and then sifted to separate and collect soil with a small organic content such as oil, etc. with a large particle size on the sieve mesh, The cement raw material may be fed into the raw material pulverization and drying step, and only the organic matter having a small organic particle size under the net, for example, may be fed into the wet mill. In this case, the soil having a large particle size on the sieve net may be crushed by a crusher and then put into a wet mill.
[0018]
Further, as described above, organic substances such as VOC contained in the waste are incinerated by being put into the high temperature atmosphere of the cement baking process.
In this case, kiln portion of the rotary kiln, since the high temperatures of above at least 800 ° C., by placing the organic material, of course it can be reliably burned the organic matter in an atmosphere of higher ignition temperature, low temperature Even if it is an organic chlorine-based organic substance that generates dioxins during combustion, the generation of the dioxins can be reliably prevented. Moreover, organic substances that are already dioxins can be decomposed into harmless substances by retaining them for 2 seconds or more in a high-temperature atmosphere of 800 ° C. or higher.
[0019]
Therefore, waste containing organic matter can be effectively used as a resource for producing high-quality cement clinker while preventing the performance of the electrostatic precipitator from deteriorating in the cement production facility without adversely affecting the environment. .
[0020]
The solvent in the method of claim 1 is characterized in that at least one of waste oil, waste liquid, sludge, water and fluidizing agent is used.
[0021]
Here, as the waste liquid, waste liquid from a pulp factory, milk collected from the market, drinking water, alcohol, or the like can be used. Moreover, as the sludge, sludge that comes out at the sewage treatment plant can be used. Moreover, as a flow agent, the water reducing agent (surfactant) etc. which mainly reduce the addition amount of water can be raised. And since waste oil, waste liquid, milk, drinking water, alcohol, sludge, etc. should be discarded originally, there is an advantage that the disposal process can be performed simultaneously.
[0022]
Furthermore , since most of the lime-based wastes are cement components, if they are wastes, the wastes can be treated effectively, and the treatment to keep the cement clinker composition within an appropriate range. Can be used as an agent.
[0023]
Moreover, even if the dioxins remain in the kiln bottom part without being completely decomposed, the rotary kiln passing through the kiln is heated at a temperature of 1450 ° C. or more for several tens of minutes or more. Therefore, the dioxins are not left in the cement clinker.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a diagram showing an outline of a cement production facility for carrying out the method for treating waste containing organic matter shown as the first embodiment of the present invention.
The cement manufacturing equipment includes a dry mill 1, a raw material silo 2, a preheater 3, a rotary kiln 5, and an electric dust collector 10. Moreover, in FIG. 1, 21 is a raw material supply flow path, 31 is an waste gas flow path.
[0025]
A cement raw material (limestone, clay, silica stone, iron raw material) G is supplied to a dry mill 1 as a raw material pulverization drying process through a dryer as necessary. These cement raw materials G are heated and pulverized in the dry mill 1 under the exhaust gas supplied from the rotary kiln 5, introduced into the raw material silo 2, and then supplied to the preheater 3 through the raw material supply passage 21. After being preheated by the preheater 3, it is put into a rotary kiln 5 for cement firing and fired to become a cement clinker. The cement firing process refers to a process from a preheating process by the preheater 3 to a cement clinker firing process by the rotary kiln 5, and corresponds to an apparatus from the preheater 3 to a kiln front part 5A described later.
[0026]
The dry mill 1 is configured to simultaneously grind and dry the cement raw material G by introducing the exhaust gas from the rotary kiln 5 through the preheater 3 and the exhaust gas flow path 31. In addition, the electrostatic precipitator 10 purifies the exhaust gas before releasing it to the atmosphere.
[0027]
The preheater 3 is a multistage cyclone type in which a plurality of cyclones 3a, 3b, 3c, and 3d are connected in multiple stages from the bottom to the top, and the crushed cement raw material G is used using the exhaust gas of the rotary kiln 5, Preheat to a predetermined temperature (800-900 ° C). The rotary kiln 5 has a horizontal cylindrical kiln shell slightly inclined downward to the downstream side, and is heated by a burner 6 using heavy oil or fine coal as a fuel while rotating the kiln shell around its central axis. The cement raw material G supplied from is heated to a temperature of 1450 ° C. or higher and subjected to a firing reaction to produce a cement clinker. Thereafter, the cement clinker is cooled by a cooler 7 connected to a kiln front part 5 </ b> A provided on the rear stage side of the rotary kiln 5, and sent to a finishing process 8. The above is the same as the operation in a normal cement production facility.
[0028]
In addition to the normal cement manufacturing facility, the cement manufacturing facility is provided with a waste treatment facility 100 mainly containing an organic substance, which includes a wet mill 11 and a slurry pump 12.
The waste-containing treatment facility 100 containing the organic matter is obtained by extracting the mixed pulverized product (crushed product) C of the waste A containing the organic matter and the solvent B with the slurry pump 12 and separating them into solid and liquid, and then rotating the obtained cake into a rotary kiln. 5 is directly put into the kiln bottom part 5B provided on the front stage side.
[0029]
Examples of waste A containing organic matter include soil containing oil such as gasoline, lubricating oil, hydraulic oil, soil containing trichlorethylene as a cleaning agent, sludge generated in sewage treatment plants, and dioxins. Soil contaminated with debris, brick debris, concrete lump, facility interior materials, etc. generated from the demolition of facilities that generate dioxins such as waste incineration ash, waste incineration facilities, and dioxins around the waste incineration facility , Such as plasterboard, glass wool, pulp sludge, wallpaper, etc. (especially fibers contaminated with dioxins), plastic molded products that may cause dioxins by combustion, organic chlorine such as chemical fibers Waste and other things are raised.
[0030]
Dioxins refer to 2,3,7,8-tetrachlorodibenzo-p-dioxin and its related compounds, and polychlorodibenzo-p- with 1-8 chlorine atoms substituted on the dibenzo-p-dioxin nucleus. It includes dioxins (PCDDs), polychlorodibenzofurans (PCDFs) in which 1 to 8 chlorine atoms are substituted in the dibenzofuran nucleus, and the like. These dioxins can be decomposed by staying in a high temperature atmosphere of 800 ° C. or higher for 2 seconds or more.
[0031]
Further, as the solvent B, it is desirable to use at least one of waste oil, waste liquid, sludge, water, and fluidizing agent. As the waste liquid, waste liquid from a pulp factory, milk collected from the market, drinking water, alcohol, and the like can be used. Moreover, as the sludge, sludge that comes out at the sewage treatment plant can be used. Moreover, as a flow agent, the water reducing agent (surfactant) etc. which mainly reduce the addition amount of water can be raised.
[0032]
And waste oil, waste liquid, milk, drinking water, alcohol, sludge, etc. have the advantage that it can be processed into harmless ones after effectively using what should be discarded as a solvent that gives fluidity.
Moreover, since fluidity | liquidity can be given to the waste A containing an organic substance by using these solvents, the mixing grinding | pulverization in the wet mill 11 can be performed smoothly and reliably, without causing a temperature rise. . Therefore, for example, even if the waste A contains a low boiling point organic substance such as trichlorethylene, the waste A can be pulverized and mixed with the solvent B while preventing the organic substance from being vaporized.
[0033]
The waste A containing the organic matter is sequentially transported to the wet mill 11 by the conveyor 15 while being temporarily stored in the waste hopper 14.
Further, the solvent B is pumped to the wet mill 11 by the pipe 17a and the pump 17b while being temporarily stored in the solvent hopper 16, and is supplied into the wet mill 11 together with the waste A.
The slurry-like mixed pulverized product C crushed and mixed by the wet mill 11 is temporarily stored in the slurry tank 18 and is obtained after being extracted from the slurry tank 18 by the slurry pump 12 and solid-liquid separated. The cake is put into the kiln bottom 5B.
[0034]
Next, the method in the case of processing the waste A containing an organic substance is demonstrated.
First, the solvent B for imparting fluidity is added to the waste A containing the organic matter and pulverized by the wet mill 11. Then, this is thrown into the kiln bottom part 5B of the rotary kiln 5 of a cement production facility, and used as a part of the cement raw material G for the production of cement clinker. That is, the mixed pulverized product C of the waste material A and the solvent B containing the organic material put into the kiln bottom portion 5B of the rotary kiln 5 is fired together with the cement raw material G and discharged as a cement clinker.
[0035]
In this way, by putting the mixed pulverized product C of the waste A containing the organic substance and the solvent B into the kiln bottom part 5B of the rotary kiln 5, the organic component can be consumed in the rotary kiln 5 as part of the fuel. Soil, brick waste, concrete lump, etc. can be used for the production of cement clinker as part of the cement raw material (clay, limestone, etc.).
[0036]
Therefore, the fuel cost for cement firing can be saved, and the cement raw material G such as clay and limestone can be saved. In addition, by crushing the waste A with the wet mill 11 as described above, it is possible to finely crush the rubble (such as stones) contained in the waste A, so that the cement clinker produced in the rotary kiln 5 It can be reliably maintained in a high quality state.
[0037]
In addition, the pulverized waste A is directly fed into the kiln bottom 5B through a route different from the normal cement raw material G, and does not pass through the dry mill 1 using the exhaust gas of the rotary kiln 5. There is no risk that organic components such as oil evaporate and adhere to the electrodes (not shown) of the electrostatic precipitator 10 to significantly reduce the performance of the electrostatic precipitator 10 or generate odors. Furthermore, it is possible to prevent the dust generated by pulverizing the concrete lump, fibers, and the like from adhering to the electrode of the electrostatic precipitator 10 and degrading the performance of the electrostatic precipitator 10.
[0038]
Moreover, organic substances, such as VOC contained in the waste A, will be incinerated by throwing in the high temperature atmosphere of 800-1100 degreeC of the kiln bottom part 5B.
In this case, the organic matter is heated to an ignition temperature or higher and incinerated, and even if it is an organic chlorinated organic matter that generates dioxins during low temperature combustion, the generation of the dioxins is surely prevented. be able to. Moreover, organic substances that are already dioxins can be decomposed into harmless substances by retaining them for 2 seconds or more in a high-temperature atmosphere of 800 ° C. or higher.
[0039]
Further, even if dioxins remain to be completely decomposed, by passing through the atmosphere of 1450 ° C. or higher of the subsequent rotary kiln 5 over several tens of minutes, Dioxins can be reliably decomposed into harmless ones. That is, dioxins do not remain in the cement clinker.
[0040]
Therefore, effectively utilizing waste A containing organic matter as a resource for producing high-quality cement clinker while preventing the performance of the electrostatic precipitator 10 from deteriorating in cement production facilities without adversely affecting the environment. Can do.
[0041]
In addition, lime- based waste, etc., becomes almost a cement component by actively mixing lime-based waste, so that the above waste can be effectively disposed of and the composition of cement clinker can be kept within an appropriate range. Therefore, there is an advantage that a large amount of waste A other than lime-based waste can be input.
[0042]
Here, come the ground mixture C of slurry that exits the wet mill 11, when put into the kiln inlet part 5B of the rotary kiln 5, as described above, is introduced from the cake by solid-liquid separation. In the case of solid-liquid separation, the separated liquid can be reused as the solvent B.
[0043]
Moreover, it is preferable to throw the massive lump A such as brick scraps and concrete lump into the wet mill 11 after crushing with a crusher.
Furthermore, before throwing into the wet mill 11, the waste A containing organic matter is stirred and mixed with the solvent B, and then sifted to separate and recover the soil with a small organic content having a large particle size on the sieve net, Alternatively, the cement raw material G may be charged into the dry mill 1 and only the organic soil having a small particle size under the net may be charged into the wet mill 11. Further, the soil having a large particle size on the sieve net may be crushed by a crusher and then put into a wet mill.
[0044]
Next, examples of processing methods will be given.
<< Processing Method 1 >>
To soil containing 0.1% to 30% (weight ratio) of oil, water (30 to 300% weight ratio) and fluid (0 to 10.0% weight ratio) are added and put into the wet mill 11, Grind for about 1-60 minutes. The slurry-like mixed pulverized product thus obtained is directly charged into the kiln bottom 5B of the rotary kiln 5. Alternatively, after the slurry-like mixed pulverized product is dehydrated, the obtained cake is put into the kiln bottom 5B of the rotary kiln 5, and the oil-mixed water is reused as a solvent.
[0045]
【The invention's effect】
As described above, according to the first aspect of the present invention, after adding a solvent for imparting fluidity to a waste containing organic matter and pulverizing it with a wet mill, this is put into a cement firing step and cement clinker is added. Because the organic component of waste including organic matter can be consumed as part of the fuel, and other components can be used as part of the cement raw material (part of clay, etc.) and cement. It can be used for the production of clinker. Accordingly, it is possible to dispose of waste containing organic matter while effectively utilizing it, and it is possible to save components such as clay as a raw material for cement and fuel for firing.
[0046]
In addition, by crushing the waste as described above, it is possible to finely pulverize the scrap (such as stones) contained in the waste, so that the cement clinker can be maintained in a high quality state.
[0047]
In addition, the waste pulverized material is directly input to the cement firing process via a different route from the normal cement raw material, and is not passed through the raw material dry pulverization process using the exhaust gas of the rotary kiln. There is no possibility that the components will evaporate and adhere to the electrode of the electrostatic precipitator for purifying the exhaust gas, so that the performance of the electrostatic precipitator is remarkably deteriorated or odor is generated. Moreover, it can also prevent that the dust produced by grind | pulverizing a concrete lump, fibers, etc. adheres to the electrode of an electrostatic precipitator, and reduces the performance of the said electrostatic precipitator.
[0048]
Furthermore, kiln portion of the rotary kiln, since a high temperature of more than at least 800 ° C., by charging the organic matter, of course it can be reliably burned the organic matter in an atmosphere of higher ignition temperature Even if it is an organic chlorine-based organic substance that generates dioxins during low-temperature combustion, the generation of the dioxins can be reliably prevented. Moreover, organic substances that are already dioxins can be decomposed into harmless substances by retaining them for 2 seconds or more in a high-temperature atmosphere of 800 ° C. or higher.
[0049]
Therefore, waste containing organic matter can be effectively used as a resource for producing high-quality cement clinker while preventing the performance of the electrostatic precipitator from deteriorating in the cement production facility without adversely affecting the environment. .
[0050]
Furthermore , as waste liquid, waste liquid that comes out from a pulp factory, milk, drinking water, alcohol, etc. collected from the market can be used, and sludge that comes out from a sewage treatment plant can be used as sludge. Therefore, there is an advantage that waste oil, waste liquid, milk, drinking water, alcohol, and sludge, which should be discarded, can be disposed of while being effectively used as a solvent.
[0051]
In addition , since most lime-based wastes are cement components, if they are wastes, the wastes can be treated effectively, and the treatment to keep the composition of the cement clinker within an appropriate range. Can be used as an agent.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic configuration diagram of a cement production facility that implements a method for treating waste containing organic matter, which is shown as a first embodiment of the present invention.
[Explanation of symbols]
A Organic waste B Solvent C Mixed ground (ground)
G Cement raw material 3 Preheater 5 Rotary kiln 5B Kiln bottom 11 Wet mill

Claims (2)

Cement raw materials are pulverized with a dry mill and preheated in a preheater, and then put into a rotary kiln for cement firing to produce a cement clinker.
After adding a solvent for imparting fluidity and lime waste to the waste containing organic matter and pulverizing with a wet mill, solid-liquid separation is performed, and the obtained cake is put into the kiln bottom of the rotary kiln, Waste containing organic matter, characterized by consuming the organic components of waste containing organic matter as part of fuel and disposing of the waste containing organic matter by using the remainder as part of cement raw material Processing method. The method for treating waste containing organic matter according to claim 1, wherein the liquid obtained by solid-liquid separation is reused as a solvent .

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