JP3960007B2 - Method for treating waste containing fibers - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention provides fibers that can be used as a part of cement raw fuel for waste containing fibers such as waste gypsum board, pulp sludge, waste including glass wool, and waste including paper. The present invention relates to a method for treating the contained waste.
[0002]
[Prior art]
Conventionally, most of the waste discharged with industrial activities has been treated by dumping in a landfill site or incineration by an incinerator. For example, wastes containing fibers such as pulp sludge, waste gypsum board, and construction materials containing glass wool have been treated in the same manner.
[0003]
However, in recent years, the capacity of landfill sites has been insufficient, and it has become difficult to secure new landfill sites due to social constraints, so it is not possible to expect landfill disposal methods. ing. Also, incineration processing by an incinerator has become difficult to implement due to a large environmental load.
[0004]
Against this backdrop, from the viewpoint of environmental conservation, recycling waste containing fibers, like plastic waste and sewage sludge, is an important social issue. Disposal as part of raw material for cement production is being promoted.
[0005]
When the waste containing such fibers is used as, for example, a part of the cement raw material, it is used as it is mixed with other cement raw materials in the raw material dry mixing and pulverizing stage. In other words, waste containing fibers is often treated by mixing it with a raw material mill or dryer that uses kiln exhaust gas together with other cement raw materials.
[0006]
[Problems to be solved by the invention]
However, when such waste containing fibers is mixed with other cement raw materials in the raw material dry mixing and grinding stage, the fibers are scattered in the exhaust gas and adhere to the electrode of the electrostatic precipitator for exhaust gas treatment. In other words, the performance of the electrostatic precipitator may be significantly reduced.
[0007]
Therefore, it is conceivable that the waste containing the fibers is directly fed into the rotary kiln of the cement firing facility without passing through the raw material dry mixing and grinding step. However, these wastes are often in the form of lumps or plates, and if introduced as they are, it is considered that the quality of cement clinker is adversely affected.
[0008]
In consideration of the above circumstances, the present invention is a treatment that can use waste containing fibers as an effective resource without degrading the performance of the electrostatic precipitator and without adversely affecting the quality of the cement clinker. It aims to provide a method.
[0009]
[Means for Solving the Problems]
In the invention of claim 1, at the time of producing cement clinker by preheating the cement raw material to 800 to 900 ° C. in a preheater and producing cement clinker, at least of waste including gypsum board, pulp sludge or paper Injecting one kind into a wet mill and using at least one of water, waste oil, waste liquid, sludge and fluidizing agent as a solvent to give fluidity to the waste, the quality of the cement clinker is affected. After crushing to a particle size not to be given, the cement clinker is manufactured by directly charging it into the kiln bottom of the rotary kiln, the calcining furnace provided in the previous stage of the rotary kiln, or the preheater.
[0013]
In the invention according to claim 1 , when treating at least one of wastes including waste gypsum board, pulp sludge or papers, the quality of the cement clinker is not affected in advance using a wet mill. Since it grind | pulverizes to the grade of a grade and it inputs into a cement baking process, it can be made not to affect the quality of a cement clinker. Further, since the raw material is not passed through the raw material dry mixing and pulverizing step using the kiln exhaust gas, the fiber material is not scattered and the performance of the electric dust collector for exhaust gas treatment is not deteriorated.
[0015]
Further, when a wet mill is employed, as in the invention of claim 2, it flows into waste by adding at least one of water, waste oil, waste liquid, sludge, and fluidizing agent as a solvent in the mill. Give sex. By doing so, lump waste can be crushed finely. Here, examples of the waste liquid include waste liquid from a pulp factory, milk and beverages collected from the market, alcohol, and the like. Moreover, as sludge, the sludge etc. which come out in a sewage treatment plant can be considered. Moreover, as a fluidizing agent, the water reducing agent (surfactant) etc. which mainly reduce the addition amount of water can be considered.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing an outline of a cement production facility for carrying out the treatment method of the present invention.
In the figure, this cement production facility includes a raw material storage 1 for storing cement raw materials made of limestone, clay, silica, and iron raw materials, a raw material mill 2 for pulverizing and mixing raw materials, an electrostatic precipitator 3, a clay dryer 4, and a raw material mixing storage silo 5 , Preheater 6, calciner 12, rotary kiln 7, clinker cooler 8, clinker silo 9, finishing mill 10, cement silo 11, and the like.
[0017]
Cement raw materials (limestone, clay, silica stone, and iron raw materials) are introduced into the raw material mill 2 through a dryer 4 as necessary. These raw materials are pulverized by the raw material mill 2 and introduced into the raw material mixing and storage silo 5, and then preheated by the preheater 6, and then passed through the calcining furnace 12 and put into the rotary kiln 7 for cement firing, After being baked by the rotary kiln 7 to become a cement clinker, cooled by the clinker cooler 8, it is introduced into the clinker silo 9.
[0018]
The preheater 6 is of a multistage cyclone type in which a plurality of cyclones are connected in multiple stages, and preheats the crushed cement raw material to a predetermined temperature (800 to 900 ° C.) using the exhaust of the rotary kiln 7. The rotary kiln 7 has a horizontal cylindrical kiln shell slightly inclined downward to the downstream side, and is heated by the burner 14 using heavy oil or fine coal as fuel while rotating the kiln shell around its central axis. The cement raw material sent 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 the clinker cooler 8 connected to the front part of the kiln of the rotary kiln 7, stored in the clinker silo 9, and then sent to the finishing mill 10 in the finishing process.
[0019]
The finishing mill 10 finely pulverizes the clinker while mixing gypsum into the cement clinker produced in the firing step, and discharges the cement. Then, the cement discharged from the finishing mill 10 is introduced into the cement silo 11 and then sent to the supplier.
[0020]
On the other hand, the gas used for preheating the cement raw material by the preheater 6 is sent from the preheater 6 to the raw material mill 2 and the clay dryer 4 where it is used for drying by waste heat and is then removed by the electric dust collector 3. The chimney 16 is released into the atmosphere.
[0021]
Next, a method for treating the waste 20 containing fibers will be described.
In this method, the waste 20 containing fibers such as waste gypsum board, pulp sludge, waste containing glass wool, waste containing paper, etc. has a particle size that does not affect the quality of cement clinker in advance. Until it becomes, it crushes with crushing means 21, such as a dry mill and a wet mill. This is because the waste 20 of this kind is often discarded as a lump. And the crushed product 22 is at least one of the kiln bottom part of the rotary kiln 7 in the cement firing step, the calciner 12 provided in the front stage of the rotary kiln 7, the preheater 6 located in the front stage of the rotary kiln 7, and the cooler bleed duct 15 The cement clinker is manufactured while effectively using the waste 20 as a part of the raw cement fuel.
[0022]
Thus, by putting the crushed product 22 of the waste 20 containing fibers into the kiln bottom of the rotary kiln 7, the combustible component can be consumed in the rotary kiln 7 as a part of the fuel, the lime component, Silica stone components, clay components, etc. can be used for the production of cement clinker as part of the cement raw material.
[0023]
Therefore, the waste 20 containing fibers can be disposed of while being effectively used, and the cement raw material and the fired fuel can be saved. In addition, since it is crushed to an appropriate particle size, there is no fear of adversely affecting the quality of the cement clinker. In addition, since the waste 20 is directly fed to the rotary kiln 7 or the like of the cement firing facility without passing through the raw material dry mixing and pulverizing step, there is absolutely no concern about the performance deterioration of the electrostatic precipitator 3 due to the adhesion of fibers. Absent.
[0024]
In addition, when using a dry mill as the crushing means 21 for the waste 20 and using a kiln exhaust gas or a cooler exhaust gas for drying the waste 20, an electrostatic precipitator is used to collect scattered matter in the exhaust gas after the mill. Instead, it is preferable to use a bag filter that does not cause deterioration of the dust collection efficiency, and put the material collected by the bag filter into the cement firing process together with the crushed product by the mill.
[0025]
When a wet mill is employed, it is desirable to add fluidity to the waste by adding at least one of water, waste oil, waste liquid, sludge, and fluidizing agent as a solvent in the mill. As a result, lump-like waste can be crushed smoothly and finely. Here, as a waste liquid, the waste liquid which comes out in a pulp factory or a semiconductor factory, milk, a drink, alcohol, etc. which were collect | recovered from the market etc. can be utilized widely. Moreover, as sludge, sludge which comes out from a sewage treatment plant, sludge which comes out from a food processing industry, etc. can be utilized widely. Moreover, as a fluidizing agent, a water reducing agent (surfactant) etc. which mainly reduce the addition amount of water can be utilized.
[0026]
In addition, when a wet mill is adopted, the slurry-like crushed product 22 coming out of the wet mill may be poured into the kiln bottom of the rotary kiln 7 as a slurry, or it is separated into solid and liquid to form a cake. You may throw it in after. In the case of solid-liquid separation, the separated liquid can be reused as a solvent again.
[0027]
【The invention's effect】
As described above, according to the invention described in claim 1, when at least one of wastes including waste gypsum board, pulp sludge or paper is brought into a cement factory for treatment, a wet mill is previously provided. Crushed into a particle size that does not affect the quality of the cement clinker, and then put into the cement firing process. The combustible components contained in the waste are used as calcined fuel, and lime, clay, silica, etc. The components can be processed so as not to affect the quality of the cement clinker while being effectively used as part of the raw cement fuel. Further, since the waste is not passed through the raw material dry mixing and pulverizing step, there is no possibility that the performance of the electrostatic precipitator is reduced.
In addition, since the waste pulverized product is introduced at least one of the kiln bottom of the rotary kiln, the calcining furnace provided in the previous stage of the rotary kiln, and the preheater located in the previous stage of the rotary kiln, the combustible material contained therein The components can be reliably burned.
[0028]
In particular, according to the second aspect of the present invention, the waste containing the fibers is mixed and pulverized by a wet mill using an appropriate solvent, so that the massive waste can be pulverized smoothly and reliably. In particular, when waste oil, waste liquid, or sludge is used as a solvent, the organic content can be used as fuel, which can contribute to saving on fuel costs and can be effectively disposed of. Become.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic configuration diagram of a cement production facility for carrying out a treatment method of the present invention.
[Explanation of symbols]
6 Preheater 7 Rotary kiln 12 Calciner 20 Waste containing fibers 21 Crushing means 22 Crushed product

Claims (1)

When the cement raw material is preheated to 800 to 900 ° C. in a preheater and then fired in a rotary kiln to produce a cement clinker, at least one of wastes including waste gypsum board, pulp sludge or papers is put into a wet mill . Crush to a particle size that does not affect the quality of the cement clinker by using at least one of water, waste oil, waste liquid, sludge, and fluidizing agent as a solvent that gives fluidity to the waste. Then, this is directly put into the kiln bottom of the rotary kiln, the calcining furnace provided in the previous stage of the rotary kiln or the preheater, and the cement clinker is manufactured to treat the waste containing fibers, Method.

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