JP2007216210A - Treating method of waste - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a treating method of waste preventing evaporation of organic chlorine compounds in a wet mill crushing waste containing organic chlorine compounds, pumping slurry after wet-crushing to a cement production facility for thermal decomposing organic chlorine compounds. <P>SOLUTION: A solvent is added to sludge containing organic chlorine compounds, sludge is charged and crushed in a wet mill 13A, while regulating a charge amount of sludge to keep the mill outlet temperature below the boiling point of the solvent. Obtained slurry is directly charged into a high temperature part of 800°C or more in the cement production facility 10 for thermally decomposing organic chlorine compounds. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a waste processing method, and more particularly to a technique for heat-treating waste containing an organic chlorine compound using a cement manufacturing facility.

Dioxins (PCDDs) are abbreviations of poly chloro dibenzo-p-dioxin and are a kind of organic chlorine compounds. Poly chloro dibenzofuran (PCDFs) is known as an analog of this dioxin.
In particular, it belongs to Tetra chloro dibenzo-p-dioxin, which is a tetrachloride of PCDDs (T4CDDs), and has chlorine at positions 2, 3, 7, 8 3,7,8-T4CDD is highly toxic.
The 2,3,7,8-tetrachloro form is obtained as a by-product in the production of trichlorophenol, 2,4,5-trichlorophenoxyacetic acid, and is obtained by chlorination of dibenzo-P-dioxin. The melting point is 306-307 ° C.

  Further, as another organic chlorine compound that is harmful to the human body, for example, PCB (polychlorinated biphenyl) is known. PCB is excellent in chemical stability, insulation, nonflammability, and adhesiveness, and has been used as an insulating oil for transformers and capacitors mounted in electric facilities such as power plants, railways, and buildings. However, it contains a coplanar PCB that has the same toxicity as that of dioisin. Therefore, in 1974, the law prohibits the manufacture, distribution and new use of PCBs.

In recent years, it has become a social issue to recycle wastes such as sludge and waste incineration ash containing organic chlorine compounds without adversely affecting the environment. As one of countermeasures, for example, the invention described in Patent Document 1 is known.
In the invention of Patent Document 1, water is adjusted by adding water to contaminated soil containing an organic chlorine compound, and this is put into a wet mill, where the contaminated soil is pulverized to an average particle size of 200 μm or less, As a raw material for cement, by supplying it to at least one of the kiln kiln bottom of the cement manufacturing facility and the lower part of the preheating device, it is a sludge soil treatment method that can easily and reliably treat contaminated soil without affecting the cement quality. is there.
JP 2003-71429 A

  However, in the invention of Patent Document 1, when a large amount of contaminated soil is added to the wet mill and its treatment amount is increased, the temperature in the wet mill is increased by the heat of grinding of the contaminated soil and added to the contaminated soil. The water had evaporated. When water evaporates in this way, the temperature in the mill further increases, and the organic chlorine compound may evaporate.

  Therefore, as a result of intensive research, the inventor has determined that a waste mill containing an organic chlorine compound and added with a solvent such as water is adjusted to a wet mill while adjusting the input amount so that the mill outlet temperature is lower than the boiling point of the solvent. If the waste is made into a slurry by putting it into a pulverizer, and then the slurry is put directly into a high-temperature part at 800 ° C. or higher in the cement production facility, the organic chlorine compound is thermally decomposed. It was discovered that waste containing an organochlorine compound can be treated by the equipment, and that this waste can be used, and the present invention has been completed.

  The present invention is capable of treating waste containing an organic chlorine compound by a cement manufacturing facility and preventing evaporation of the organic chlorine compound in the wet mill when the waste is wet-ground using the wet mill. An object of the present invention is to provide a waste disposal method that can use waste.

  Another object of the present invention is to provide a waste processing method that can smoothly pump a slurry of waste, and that the solid content in the slurry hardly affects the firing of the cement clinker.

  Furthermore, an object of the present invention is to provide a waste treatment method that becomes a grinding aid during grinding of waste, increases the fluidity of the obtained slurry, and facilitates the pumping of the slurry by a pump. Yes.

  The invention according to claim 1 includes a solvent addition step of adding a solvent that imparts fluidity to the waste to the waste containing the organic chlorine compound, and a waste to which the solvent is added, A slurry preparation step of preparing a slurry by charging into a wet mill and pulverizing while adjusting the input amount so that the temperature is lower than the boiling point of the solvent, and the slurry is 800 ° C. or more in the cement manufacturing facility And a thermal decomposition step of thermally decomposing the organochlorine compound.

  According to the first aspect of the invention, first, a solvent is added to the waste containing the organic chlorine compound in order to prevent volatilization and scattering of the organic chlorine compound in the wet mill, and then the waste to which the solvent is added. Is put into a wet mill while adjusting the amount of the feed so that the mill outlet temperature is lower than the boiling point of the solvent, and the waste is pulverized and mixed here. In this way, the waste is slurried. Thereafter, the slurry is directly charged into a high temperature part of 800 ° C. or higher in the cement production facility using a pressure pump. Thereby, while the waste containing an organic chlorine compound can be processed with a cement manufacturing facility, waste can be utilized as a manufacturing resource of a cement clinker. Moreover, since the amount of waste input is adjusted based on the outlet temperature of the wet mill as described above, the organic chlorine compound does not evaporate in the wet mill.

  Examples of waste containing organic chlorine compounds include soil containing oil such as gasoline, lubricating oil, hydraulic oil, soil containing trichlorethylene as a cleaning agent, waste incinerated ash containing water-containing sludge, dioxins and PCB, Contaminated with materials or substances (such as rubble, brick scraps, concrete lumps and facility interior materials) generated during the dismantling of facilities that generate dioxins and PCBs such as garbage incineration facilities, and dioxins and PCBs around the waste incineration facilities Soil can be included. In addition, fibers such as gypsum board, glass wool, pulp sludge, wallpaper, etc., plastic molded products that have a risk of generating dioxins and PCBs by combustion, organochlorine waste such as chemical fibers, cement Dust in the production facility can be used.

As the wet mill, for example, a ball mill, a rod mill, a pan mill, a stirring and grinding mill and the like can be employed. Moreover, the existing mill (mill which can be wet-ground) provided in the cement manufacturing facility may be used.
The waste is pulverized by a wet mill. Therefore, the temperature in the wet mill does not easily rise during pulverization. Therefore, even if the waste contains a low-boiling organic chlorine compound such as trichlorethylene, the waste can be pulverized well while suppressing vaporization of the organic chlorine compound.
The pulverized waste is put into a high temperature part at 800 ° C. or higher in the cement manufacturing facility. For example, the organochlorine compound is consumed as a part of the fuel by being put into the firing step of the cement clinker. In addition, soil, brick waste, concrete blocks, etc. are used in the production of cement clinker as part of the cement raw material (part of clay, limestone, etc.). Therefore, it is possible to reduce the fuel cost for firing the clinker, and also to reduce the cost of cement raw materials such as clay and limestone. In addition, by pulverizing the waste, the portion of the waste in the waste is finely pulverized. Thereby, a cement clinker can be manufactured without deteriorating quality.

  In addition, the pulverized waste is put into the high temperature part of the cement manufacturing facility by a route different from that of ordinary cement raw materials. That is, the pulverized waste is not passed through a raw material process section that uses exhaust gas from a rotary kiln. Thereby, organic components, such as oil, evaporate and it adheres to the electrode of the electrostatic precipitator which purifies exhaust gas, and there is no possibility that the performance of an electrostatic precipitator will fall or generate odor.

Examples of the solvent (a liquid substance that dissolves waste, or a thin liquid when the waste is liquid) include, for example, water, oil (light oil, soybean oil, etc. that have a high boiling point and are difficult to volatilize), Various organic solvents, waste oil, waste liquid, sludge and slurry having a high water content can be used.
The boiling point of the solvent is, for example, 100 ° C for water, 180 to 370 ° C for light oil, and 300 to 350 ° C for soybean oil.

The mill outlet temperature is the temperature near the slurry outlet of the wet mill. If the outlet temperature of the wet mill is equal to or higher than the boiling point of the solvent, the solvent may evaporate and disappear.
Therefore, the mill outlet temperature is adjusted to be lower than the boiling point of the solvent. This is due to adjusting the input amount of the waste to which the solvent is added. Specifically, the amount of waste added to the mill so that the temperature in the wet mill does not rise above the boiling point of the solvent due to the heat of grinding generated when grinding the waste in the wet mill. Is adjusted.

In addition, for large lump waste such as brick scraps and concrete lumps, it is preferable to throw them into a wet mill after crushing using a crusher.
Furthermore, before putting into a wet mill, waste containing an organic chlorine compound is stirred and mixed with a solvent, and then this is sieved to separate and recover soil with a large particle size and a small amount of organic matter such as oil. While the raw material is fed into the raw material process section, only the organic matter with a fine organic particle size under the net may be fed into the wet mill. In that case, the soil having a large particle size on the sieve net may be put into a crusher in advance and pulverized, and then put into a wet mill.

As the cement manufacturing facility, for example, a rotary kiln using a firing device can be employed. Moreover, you may employ | adopt what has the preheater connected with the kiln bottom part of a rotary kiln, a calcining furnace, etc.
As a high temperature part which becomes 800 degreeC or more in a cement manufacturing equipment, for example, the downstream part (850 degreeC) of the preheater of a baking process part, the calcining furnace (850 degreeC) provided between the preheater and the rotary kiln, A kiln bottom part (1000 degreeC), the high temperature part (800 degreeC or more) of the kiln front part (1450 degreeC) of a rotary kiln, etc. are mentioned. One of these may be charged with all of the slurry containing the organochlorine compound, or the slurry may be charged into a plurality of these or all of them in a predetermined ratio.
When the high temperature part is less than 800 ° C., organic chlorine compounds such as dioxins and PCBs cannot be completely thermally decomposed. The preferable temperature of the high temperature part is 850 ° C. or higher. If it is this temperature, organic chlorine compounds, such as dioxins and PCB, can be thermally decomposed completely, for example.

Direct injection of slurry into a high-temperature part at 800 ° C. or higher in a cement production facility by a pumping pump means that the exhaust gas from the rotary kiln does not pass through the system (pipe) of the raw material process part used as a heat source, and the slurry is heated to high temperature. This refers to direct input to the department. As a result, the organic chlorine compound containing waste is evaporated by the heat of the exhaust gas, and it adheres to the electrode of the electrostatic precipitator that purifies the exhaust gas, and there is no risk of degrading the performance of the electrostatic precipitator or generating odor .
As a method for charging the slurry into the high temperature part, pressure feeding by a pressure feeding pump is employed. For example, a diaphragm pump, a tube pump, a snake pump, a rotary pump, or the like can be adopted as the type of the pressure pump.

  The firing temperature of the cement, for example, the temperature in the rotary kiln is usually 1100 to 1450 ° C., which exceeds the thermal decomposition temperature of the organochlorine compound. Therefore, the organic chlorine compound is thermally decomposed and rendered harmless when the cement clinker is fired. The firing time of the rotary kiln at this time (raw material residence time = thermal decomposition time of the organic chlorine compound) is 0.5 to 1 hour. The organochlorine compound is decomposed by heating for several seconds at 900 ° C., for example. Moreover, even in the case of wastes containing precursors that generate dioxins during low temperature combustion, the treatment at this high temperature can prevent the generation of dioxins.

  The invention according to claim 2 is the waste processing method according to claim 1, wherein the addition ratio of the solvent is 10 to 200% by weight of the total weight of the solvent and the waste.

If it is less than 10% by weight, it becomes difficult to transport the slurry. On the other hand, if it exceeds 200% by weight, the loss of thermal efficiency in the high-temperature part of the cement production facility into which the slurry has been charged increases.
A preferable addition ratio of the solvent is 30 to 80% by weight of the total weight of the solvent and the waste. If it is this range, the more suitable effect that fluidity | liquidity is excellent is acquired.

  Invention of Claim 3 is a waste processing method of Claim 1 or Claim 2 whose viscosity of the said slurry is 100-10000 mPa * s and whose average particle diameter of this slurry is 10-50 micrometers. .

  According to the invention described in claim 3, since the viscosity of the slurry is 100 to 10,000 mPa · s, the slurry can be smoothly pumped, and the average particle of the slurry (especially the waste contained therein) Since the diameter is 10 to 50 μm, the solid content in the slurry hardly affects the firing of the cement clinker.

When the viscosity of the slurry is less than 100 mPa · s, the solvent is large and the heat loss is large. The preferred viscosity of the slurry is 1000 mPa · s to 3000 mPa · s. If it exceeds 3000 mPa · s, the transport pipe may be blocked. If it is this range, the fluidity | liquidity of a slurry will be excellent.
When the average particle size of the slurry is less than 10 μm, excessive power or the like is required for the pulverization. Moreover, when it exceeds 50 micrometers, it may lead to the quality fall of a cement clinker. A preferred average particle size is 10 to 50 μm.

  The invention according to claim 4 is the waste processing method according to any one of claims 1 to 3, wherein the solvent is at least one of water, waste liquid, and sludge. .

The solvent may be any one of water, waste liquid, and sludge, or any two arbitrarily selected. Furthermore, all three of these may be used.
The waste liquid is various factory waste liquids (pulp waste liquid and the like), and the sludge is sludge (paper sludge and the like) in various factories.

  Invention of Claim 5 adds the water reducing agent to the said solvent 0.1 weight part or less with respect to 100 weight part of said solvents, The disposal of any one of Claims 1-4 It is a processing method of a thing.

  According to the fifth aspect of the present invention, since the water reducing agent is added to the solvent in an amount of 0.1 part by weight or less with respect to 100 parts by weight of the solvent, it becomes a waste grinding aid during grinding by the wet mill and is obtained. The fluidity of the slurry is increased, and the slurry can be easily pumped by the pump.

As the water reducing agent, lignin type, naphthalene type, polycarboxylic acid type and the like can be used.
When the addition amount of the water reducing agent exceeds 0.1 parts by weight with respect to 100 parts by weight of the solvent, the cost increases.

  According to this invention, the waste to which the solvent is added is put into a wet mill while adjusting the amount of the feed so that the mill outlet temperature is lower than the boiling point of the solvent, and the waste is pulverized into a slurry. Let Thereafter, the slurry was directly fed into a high temperature part of 800 ° C. or higher in the cement production facility using a pressure feed pump. Thereby, the waste containing the organic chlorine compound can be processed by the cement manufacturing facility, and the waste can be used as a manufacturing resource of the cement clinker without deteriorating the quality of the cement clinker. Moreover, the organic chlorine compound does not evaporate in the wet mill.

  In particular, according to the invention described in claim 3, since the viscosity of the slurry is 100 to 10,000 mPa · s, the slurry can be smoothly pumped and the average particle diameter of the slurry is 10 to 50 μm. The solid content in the slurry is unlikely to affect the firing of the cement clinker.

  Further, according to the invention described in claim 5, since the water reducing agent is added to the solvent at a ratio of 0.1 parts by weight or less with respect to 100 parts by weight of the solvent, it becomes a grinding aid when grinding the waste, The fluidity of the obtained slurry is increased, and the slurry can be easily pumped by a pump.

  Examples of the present invention will be specifically described below.

  In FIG. 1, reference numeral 10 denotes a cement firing facility to which the waste processing method according to Embodiment 1 of the present invention is applied. The cement firing facility 10 includes a raw material process part A for grinding a cement raw material and a firing process part B for firing the ground cement raw material.

The raw material process section A includes a raw material storage 11 for individually storing limestone, clay, silica and iron raw materials as cement raw materials, a raw material dryer 12 for heating and drying cement raw materials having a high water content such as clay, and cement. A solvent (waste liquid) is added to the raw material mill 13 for crushing raw materials and sludge containing oil (waste) to prevent volatilization and scattering of organic chlorine compounds in the wet mill, and the solid content in the sludge is crushed. A wet mill 13A for mixing while mixing, a first dust collector B1 for collecting dust (powder) discharged from the raw material dryer 12 and the raw material mill 13, and a storage for temporarily storing the pulverized raw material discharged from the raw material mill 13 And a silo 14.
In the raw material mill 13 and the wet mill 13A, many iron balls having a diameter of 10 to 100 mm are accommodated in a rotating drum.

  The cement raw material stored in the raw material storage 11 is put into the rotating drum of the raw material mill 13 through the raw material transporting equipment 118. However, a part of the cement raw material having a high water content is supplied to the raw material dryer 12 through the high water content raw material supply facility 131. This part of the cement raw material is heated and dried here, and then fed into the raw material mill 13 through the dry raw material discharge facility 132. High temperature exhaust gas is supplied to the raw material dryer 12 and the raw material mill 13 through an exhaust gas duct 21 from an upper portion of a preheater 16 described later. Therefore, the internal temperature of the raw material dryer 12 is about 300 ° C., and the internal temperature of the raw material mill 13 is 100 ° C. or higher. A fan F <b> 1 is provided upstream of the exhaust gas duct 21.

A large number of metal balls are accommodated in the rotating drum of the raw material mill 13. By continuously feeding the cement raw material while rotating the rotating drum, the cement raw material is pulverized to about 90 μm or less. The crushed cement raw material is input to the storage silo 14 through the pulverized raw material transport facility 121.
A large number of metal balls are also stored in the rotating drum of the wet mill 13A. The solid content in the sludge is pulverized by continuously adding the solvent and sludge while rotating the rotating drum. The slurry thus obtained is arbitrarily passed through the pulverized sludge transport facilities 22A to 22C to the lower stage of the preheater 16, the kiln bottom of the rotary kiln 18, and the kiln front of the rotary kiln 18 by the pumping force of the slurry pump (pumping pump) 150. To be pumped. Each of the pulverized sludge transport facilities 22A to 22C is provided with one valve 151A to 151C for opening and closing the slurry flow path.

  The raw material dryer 12 and the raw material mill 13 are connected to respective end portions of the bifurcated upstream portion of the flue 129 for releasing the exhaust gas from the inside through the chimney 130 to the atmosphere. In the middle of the downstream portion of the flue 129, an electric dust collector B1 is provided. The dust collection dust containing the organic chlorine compound collected by the electric dust collector B1 is fed into the wet mill 13A through the dust delivery pipe 123 from the raw material inlet. Further, the flue 129 is provided with a fan F2 on the side of the material mill 13 at the upstream of the bifurcated portion, and a fan F3 is provided between the electric dust collector B1 and the chimney 130.

  In the firing process part B, the cement raw material from the storage silo 14 is connected to the preheater 16 provided with a multistage cyclone 15 whose internal temperature is higher in the lower (downstream) part, and the lower part of the preheater 16 is connected to the kiln bottom. The rotary kiln 18 for obtaining cement clinker by baking the cement raw material by heating with the combustion burner 17, the clinker cooler 19 for cooling the cement clinker discharged from the front of the kiln of the rotary kiln 18, and the obtained cement clinker are once stored. A clinker silo (not shown) is provided.

The preheater 16 is a multi-stage tower that preheats the cement raw material while passing the upper and lower cyclones 15 sequentially from the upper one so that the cement raw material crushed by the raw material mill 13 can be easily fired by the rotary kiln 18 in the next step. is there. An upstream end of the exhaust gas duct 21 is connected to the upper portion of the preheater 16.
The rotary kiln 18 produces cement clinker at, for example, 100 t / h. The rotary kiln 18 has a rotatable kiln shell lined with a refractory, and inside thereof, cement clinker is fired from the cement raw material by the heat of the flame from the combustion burner 17 using heavy oil or fine coal as fuel.
That is, in the firing step B, the cement raw material from the storage silo 14 is supplied to the preheater 16 through the heated raw material powder pipe 165, and each cyclone 15 is preheated while flowing down. Then, the cement raw material is heated by the combustion burner 17 while rotating in the kiln shell. Thereby, a cement clinker is baked. The obtained cement clinker is cooled inside the clinker cooler 19.

Next, a waste disposal method performed in the cement production facility 10 of Example 1 (inside the system) will be described.
As shown in FIG. 1, each cement raw material in the raw material storage 11 is put into the raw material mill 13 via the raw material transport facility 118. However, only a part of the cement raw material having a high water content is supplied to the raw material dryer 12 through the high water content raw material supply facility 131. The clay is heated and dried in the raw material dryer 12, and then passed through the dry raw material discharge facility 132 and charged into the raw material mill 13. High temperature exhaust gas is supplied to the raw material dryer 12 and the raw material mill 13 from above the preheater 16 through the exhaust gas duct 21. Therefore, the inside of the raw material dryer 12 is about 300 ° C., and the inside of the raw material mill 13 is 100 ° C. or higher. In the raw material mill 13, the cement raw material containing the dry clay supplied from the raw material dryer 12 is pulverized to a particle size of approximately 90 μm or less by a large number of metal balls while being heated to about 100 ° C. The pulverized cement raw material is fed into the storage silo 14 through the pulverized raw material transport facility 121.

The cement raw material stored in the storage silo 14 is then supplied to the firing process section B, where it finally flows from the uppermost cyclone 15 of the preheater 16 to the lower cyclone 15 and finally reaches 800 ° C. Heated to a degree. Thereafter, the cement raw material is charged into the kiln bottom of the rotary kiln 18, and the cement clinker is fired by heating with the combustion burner 17. The obtained cement clinker is cooled by a clinker cooler 19.
The wet mill 13A is continuously charged with sludge containing oil and solvent in the rotating drum at a weight ratio of 100: 70. Also, the dust collection dust from the electric dust collector B1 is continuously fed into the rotating drum through the dust delivery pipe 123. The rotating speed of the rotating drum is about 30 rpm. The input amount of the dust collection dust is about 20% by weight with respect to the slurry. The solid content in the sludge is pulverized in a wet manner by stirring for 10 minutes in a rotating drum until the average particle size becomes approximately 20 μm. A slurry is thus obtained.

The viscosity of the slurry is 1000 mPa · s, and the average particle size of waste such as sludge contained in the slurry is 30 μm. Since the viscosity of the slurry is 1000 mPa · s, the slurry can be pumped smoothly. In addition, since the average particle size of the waste in the slurry is set to 30 μm, the solid content in the slurry hardly affects the firing of the cement clinker.
Sludge and solvent are charged into the wet mill 13A while adjusting the input amount so that the mill outlet temperature is lower than the boiling point (100 ° C.) of the solvent. Specifically, the mill outlet temperature is continuously measured, and the input amounts of sludge and solvent are adjusted based on the measurement result. As described above, since the input amount of the waste is adjusted based on the outlet temperature of the wet mill 13A, the organic chlorine compound does not evaporate in the wet mill 13A.
Further, a naphthalene-based water reducing agent is added to the solvent at a ratio of 0.1 part by weight with respect to 100 parts by weight of the solvent. Thus, when the solid content in the slurry is pulverized by the wet mill 13A, the water reducing agent becomes a pulverization aid, the fluidity of the obtained slurry is increased, and the slurry pump 150 is smoothly pumped.

The obtained slurry is opened by arbitrarily selecting each of the on-off valves 151A to 151C, and the pressure of the slurry pump 150 is used to feed the lower stage of the preheater 16 and the kiln bottom of the rotary kiln 18 through the pulverized sludge transport facilities 22A to 22C. And the kiln front part of the rotary kiln 18. These are all high temperature portions of 800 ° C. or higher in the cement manufacturing facility 10. Therefore, organic chlorine compounds harmful to the human body such as dioxins and PCBs contained in the sludge are decomposed by the heat of the high temperature part of 800 ° C. or higher.
In addition, since the wet mill 13A is used for sludge crushing, the temperature in the mill hardly rises during crushing. Thereby, even if the sludge contains a low boiling point organic chlorine compound such as trichlorethylene, the sludge can be wet pulverized well while suppressing the vaporization of the organic chlorine compound.

Furthermore, when the obtained slurry is put into a high-temperature part at 800 ° C. or higher in the cement manufacturing facility 10, the organochlorine compound is consumed as part of the fuel. Moreover, the solid content of the sludge is used for the production of cement clinker as part of the cement raw material (part of clay, limestone, etc.). Therefore, the fuel cost for firing the cement clinker can be reduced, and the cement raw materials such as clay and limestone can be saved. Moreover, this solid content is grind | pulverized finely by grind | pulverizing the solid content of sludge. Thereby, a cement clinker can be manufactured without deteriorating quality.
In addition, the slurry is directly fed to the high temperature portion of the cement manufacturing facility 10 by a pumping force of the slurry pump 150 via a route (through an independent pipe) different from the normal cement raw material. Therefore, the slurry does not pass through the system (pipe) of the raw material process part A where the exhaust gas of the rotary kiln 18 is used as a heat source. Thereby, organic components, such as oil, evaporate, and it adheres to the electrode of electrostatic precipitator B1 which carries out purification processing of waste gas, and there is no possibility that the performance of electric precipitator B1 will fall or generate odor.

For example, the case where a slurry is thrown into the kiln bottom part of the rotary kiln 18 is demonstrated. In the rotary kiln 18, the cement raw material is heated at 1100 to 1450 ° C., which exceeds the thermal decomposition temperature of dioxin. Moreover, for example, the kiln shell rotates at a low speed in the circumferential direction at a rotation speed of 1 to 3 rpm. Therefore, the pulverized material containing the introduced organic chlorine compound is heated in the rotary kiln 18 for 30 minutes or more. As a result, the cement clinker is fired, and at the same time, all of the organic chlorine compounds such as dioxins and PCBs contained in the crushed material are thermally decomposed and rendered harmless.
When the organochlorine compound is PCB, the heating temperature must be 500 to 800 ° C. in order to sufficiently evaporate it from the powder. For example, when the PCB residual ratio when dust collection dust is not heated is set to 100%, the relationship between the heat treatment temperature and the PCB residual ratio is investigated. When the heat treatment temperature is 300 ° C., the PCB residual ratio is 25%, In the cases of 500 ° C. and 800 ° C., the PCB residual ratio was 5%, respectively.

Here, the reduction rate of organic chlorine compounds in the exhaust gas released to the atmosphere before and after application of the treatment by the wet mill 13A using the cement production facility 10 of Example 1 (heating raw material use basic unit: 50 kg / t.cli) Report the results of the survey.
Of the organic chlorine compounds contained in the exhaust gas, compared to the case of using the same cement production equipment as before, THC (total organic gas) is 72%, dioxins are 85%, PCBs is 96%, and benzene is 76%. Diminished.

It is a schematic block diagram of the cement baking equipment to which the waste processing method which concerns on Example 1 of this invention was applied.

Explanation of symbols

10 Cement production equipment,
13A wet mill,
16 Lowermost part of preheater (high temperature part),
18 Rotary kiln (high temperature part),
150 Slurry pump (pressure pump).

Claims (5)

A solvent addition step of adding a solvent that imparts fluidity to the waste to the waste containing the organic chlorine compound;
A slurry preparation step of preparing a slurry by charging the waste added with this solvent into a wet mill while adjusting the input amount so that the mill outlet temperature is less than the boiling point of the solvent, and pulverizing,
A waste treatment method comprising a thermal decomposition step in which this slurry is directly fed into a high-temperature portion at 800 ° C. or higher in a cement production facility by a pressure pump to thermally decompose the organochlorine compound.   The method for treating waste according to claim 1, wherein an addition ratio of the solvent is 10 to 200% by weight of a total weight of the solvent and the waste.   The waste processing method according to claim 1 or 2, wherein the slurry has a viscosity of 100 to 10,000 mPa · s, and an average particle size of the slurry is 10 to 50 µm.   The waste treatment method according to any one of claims 1 to 3, wherein the solvent is at least one of water, waste liquid, and sludge.   The waste disposal method according to any one of claims 1 to 4, wherein a water reducing agent is added to the solvent at a ratio of 0.1 parts by weight or less with respect to 100 parts by weight of the solvent.

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