JP6859804B2 - Sludge and powder treatment method, cement clinker manufacturing method and cement manufacturing method - Google Patents

Description

The present invention relates to a method for treating sludge and powder, a method for producing cement clinker, and a method for producing cement.

Conventionally, for example, various treatment methods for powder waste plastics such as waste toner have been proposed. For example, Patent Document 1 describes a method of mixing powder waste plastic and sewage sludge and incinerating the kneaded product.

Japanese Unexamined Patent Publication No. 2006-341535

Since powder waste plastics having a small particle size such as waste toner tend to aggregate, when trying to uniformly mix them with those containing a large amount of liquid components such as sewage sludge, a special case as described in Patent Document 1 is made. Equipment is required. Without using such a special device, it is difficult to uniformly mix a powder having a small particle size with a powder containing a large amount of liquid components such as sewage sludge. If the powder and sewage sludge are not uniformly mixed, there is a possibility that problems such as uneven combustion may occur during the incineration process. Therefore, in order to suitably treat the powder and sludge, there is a demand for uniformly mixing the powder and sludge.

A main object of the present invention is to provide a sludge and powder treatment method capable of suitably mixing sludge and powder.

In the sludge and powder treatment method according to the present invention, sludge, a first powder having an average particle size of 500 μm or less, and a second powder having an average particle size of 1 mm or more are kneaded to prepare a kneaded product. obtain. Burn the kneaded material. In the sludge and powder treatment method according to the present invention, a second powder having a relatively large average particle size of 1 mm or more is added to the first powder and sludge having a small average particle size. Therefore, the second powder functions like a pulverization medium, the first powder having a small average particle size does not become lumpy, and the first and second powders and sludge are highly uniform. Can be kneaded with. Therefore, the obtained kneaded product can be used, for example, as a fuel having a stable calorific value. Further, since the first powder having a small average particle size is taken into the sludge and no dust is generated, it is possible to suppress a dust explosion.

In the sludge and powder treatment method according to the present invention, the kneaded material may be put into a cement clinker firing step or a boiler.

In the sludge and powder treatment method according to the present invention, the first powder may be at least one selected from the group consisting of toner, wheat flour, polymer powder, plastic powder, shavings and metal powder.

In the sludge and powder treatment method according to the present invention, the second powder may be at least one of plastic powder and wood powder.

In the sludge and powder treatment method according to the present invention, the sludge may be at least one selected from the group consisting of sewage sludge, industrial wastewater sludge and human waste sludge.

In the sludge and powder treatment method according to the present invention, it is preferable to further perform a reduction step of reducing the water content of the kneaded product by fermenting the kneaded product, which is performed prior to the combustion step.

In the method for producing a cement clinker according to the present invention, sludge, a first powder having an average particle size of 500 μm or less, and a second powder having an average particle size of 1 mm or more are kneaded to obtain a kneaded product. A firing process for producing cement clinker is performed by firing the raw material of cement clinker. The kneaded product is put into the firing process. In the method for producing a cement clinker according to the present invention, a second powder having an average particle size of 1 mm or more is mixed with a first powder having an average particle size and sludge. Therefore, the first powder having a small average particle size does not become lumpy, and the first and second powders and sludge can be kneaded with high uniformity. Therefore, the obtained kneaded product is used in the firing step as, for example, a fuel having a stable calorific value. Therefore, the firing step can be performed stably. In addition, it is possible to suppress the dust explosion of the first powder having a small average particle size.

In the method for producing cement clinker according to the present invention, it is preferable to put the kneaded material into at least one place of the preheater, the calcining furnace and the kiln tail of the kiln and burn it in the firing step.

In the method for producing a cement clinker according to the present invention, the first powder may be at least one selected from the group consisting of toner, wheat flour, polymer powder, plastic powder, shavings and metal powder.

In the method for producing cement clinker according to the present invention, the second powder may be at least one of plastic powder and wood powder.

In the method for producing a cement clinker according to the present invention, the sludge may be at least one selected from the group consisting of sewage sludge, factory effluent sludge and human waste sludge.

In the method for producing cement clinker according to the present invention, it is preferable to further perform a reduction step of reducing the water content of the kneaded product by fermenting the kneaded product, which is performed prior to the firing step.

In the method for producing cement according to the present invention, the cement clinker is produced by the method for producing cement clinker according to the present invention. Manufacture cement from cement clinker.

According to the present invention, it is possible to provide a sludge and powder treatment method capable of preferably mixing sludge and powder.

It is a schematic diagram of a part of the cement manufacturing apparatus which concerns on one Embodiment of this invention.

Hereinafter, an example of a preferred embodiment in which the present invention has been carried out will be described. However, the following embodiments are merely examples. The present invention is not limited to the following embodiments.

FIG. 1 is a schematic view of a part of the cement manufacturing apparatus 1 according to the present embodiment. Specifically, FIG. 1 shows the cement clinker firing device 10 and the kneading section 20 of the cement manufacturing device 1.

As shown in FIG. 1, the raw material is charged into the firing device 10. Here, it is assumed that the raw material to be input includes the raw material of cement clinker and the fuel consumed in the firing described later. Examples of the raw material charged into the firing apparatus 10 include organic sludge.

The raw materials are crushed and mixed by a raw material crusher (raw material mill) (not shown), and then charged into the firing device 10 shown in FIG. Specifically, the raw material is charged into the preheater 11 of the firing device 10. The raw material is preheated by the preheater 11. The preheater 11 is preferably composed of, for example, a suspension preheater. This is because the preheating efficiency of the raw material can be improved.

A calcining furnace 12 is connected to the preheater 11. The raw material preheated in the preheater 11 is transferred to the calcining furnace 12. The preheated raw material is thermally decomposed in the calcining furnace 12 maintained in the reducing atmosphere.

The calcining furnace 12 is connected to a kiln 13 such as a rotary kiln. The raw material thermally decomposed in the calcining furnace 12 is put into the kiln tail 13a of the kiln 13. The charged raw material is heated by a main burner (not shown) provided in front of the kiln 13b of the kiln 13 to form a cement clinker.

The kiln 13b in front of the kiln 13 is connected to the clinker cooler 14. The cement clinker produced in the kiln 13 is cooled in the clinker cooler 14, and the cooled cement clinker is discharged from the clinker cooler 14.

In the present invention, the firing apparatus used in the firing step may be provided with a kiln, and does not necessarily have to be provided with a preheater or a calcining furnace.

The manufactured cement clinker is connected to a finishing mill (not shown). In this finishing mill, cement is produced by crushing and mixing cement clinker together with gypsum, blast furnace slag, fly ash, etc., which play a role in adjusting the hardening rate of cement.

As shown in FIG. 1, the cement manufacturing apparatus 1 is provided with a kneading portion 20. Sludge and first and second powders are supplied to the kneading section 20. The sludge supplied to the kneading section 20 and the first and second powders are kneaded in the kneading section 20. In the present invention, sludge and materials other than the first and second powders may be supplied to the kneading portion and kneaded. For example, in addition to sludge and the first and second powders, kitchen waste and the like may be supplied to the kneading portion.

The kneaded product obtained by the kneading unit 20 is put into a firing step and used as fuel. By doing so, the amount of fuel required in the firing process can be reduced.

By the way, for example, as described in Patent Document 1, when a powder having a small average particle size and sludge are mixed, the powder may become lumpy and the sludge and the powder may not be uniformly mixed. .. In that case, the calorific value obtained when the mixture is burned becomes uneven.

In the present embodiment, in the kneading step performed in the kneading section 20, sludge, a first powder having an average particle size of 500 μm or less, and a second powder having an average particle size of 1 mm or more are kneaded and kneaded. To get. Therefore, the second powder having an average particle diameter of 1 mm or more functions like a pulverizing medium and suppresses the first powder from becoming lumpy. Therefore, the first powder having a small average particle size does not become lumpy, and the first and second powders and sludge can be kneaded with high uniformity. Therefore, the obtained kneaded product is used in the firing step as, for example, a fuel having a stable calorific value. Therefore, the firing step can be performed stably. Further, since the first powder having a small average particle size is taken into the sludge and no dust is generated, it is possible to suppress a dust explosion.

The average particle size of the first powder is 500 μm or less, preferably 100 μm or less. However, if the average particle size of the first powder is too small, there is a risk that a kneaded product having sufficiently high uniformity cannot be obtained even if the second powder is mixed. Therefore, the average particle size of the first powder is preferably 5 μm or more, and more preferably 50 μm or more.

The average particle size of the second powder is preferably 1 mm or more and 50 mm or less, and more preferably 10 mm or more and 40 mm or less, from the viewpoint of preventing the first powder from becoming lumpy.

In the present invention, the "average particle size" of the powder can be measured by using a laser diffraction / scattering particle size distribution measuring device LA960 manufactured by HORIBA, Ltd. when the average particle size is less than 750 μm. it can. When the average particle size is 750 μm or more, it can be measured using a sieve.

The first powder is not particularly limited, and examples thereof include toner, wheat flour, polymer powder, plastic powder, shavings, and metal powder. Specific examples of the polymer powder include powder produced by crushing a urethane heat insulating material. Only one kind of these powders may be used, or a plurality of kinds may be used.

Specific examples of the second powder include plastic powder, wood powder, and the like. Only one kind of these powders may be used, or a plurality of kinds may be used.

Specific examples of sludge include organic sludge such as sewage sludge, urine sludge, food waste sludge, blue-green algae, bottom sludge, food processing residue, and industrial wastewater sludge, and inorganic sludge. Specific examples of food processing residues include beer grounds, tea grounds, livestock residues and the like. Only one kind of these powders may be used, or a plurality of kinds may be used. The sludge can be mixed with the first powder and the second powder by using a general mixer such as a screw mixer, a pan-type mixer, or a rotary swing mixer.

Further, in the present embodiment, it is preferable to further perform a reduction step of reducing the water content of the kneaded product by fermenting the kneaded product, which is performed as sludge prior to the firing step. By doing so, the water content of the kneaded product decreases due to the heat of fermentation. Therefore, the amount of heat required to evaporate the water content when burning the kneaded product can be reduced. That is, the amount of heat per unit volume or unit mass of the kneaded product can be increased. Therefore, the amount of fuel required for the production of cement clinker can be reduced.

The place where the kneaded product is put is not particularly limited. The kneaded product can be put into at least one of the preheater 11, the calcining furnace 12, and the kiln 13, for example. Above all, it is preferable to put the kneaded material into at least one of the preheater 11, the calcining furnace 12 and the kiln tail 13a of the kiln 13, and it is more preferable to put it into the calcining furnace 12. This is because the mixed product can be used not only as a raw material for cement but also as an auxiliary fuel in the calcining furnace 12.

In this embodiment, an example in which the kneaded product is put into the firing step of the cement clinker and burned has been described. However, in the present invention, the destination of the kneaded product is not limited to this. For example, the kneaded material may be put into a boiler or the like of a power plant and burned.

1: Manufacturing equipment 10: Firing equipment 11: Preheater 12: Temporary firing furnace 13: Kiln 13a: Kiln butt 13b: Kiln front 14: Clinker cooler 20: Kneading part

Claims (11)

A step of kneading sludge, a first powder having an average particle size of 500 μm or less, and a second powder having an average particle size of 1 mm or more to obtain a kneaded product.
The process of burning the kneaded product and
A reduction step of reducing the water content of the kneaded product by fermenting the kneaded product, which is performed prior to the combustion step,
A method for treating sludge and powder. The method for treating sludge and powder according to claim 1, wherein the kneaded product is put into a cement clinker firing step or a boiler and burned. The method for treating sludge and powder according to claim 1 or 2, wherein the first powder is at least one selected from the group consisting of toner, wheat powder, polymer powder, plastic powder, shavings and metal powder. The method for treating sludge and powder according to any one of claims 1 to 3, wherein the second powder is at least one of plastic powder and wood powder. The method for treating sludge and powder according to any one of claims 1 to 4, wherein the sludge is at least one selected from the group consisting of sewage sludge, industrial wastewater sludge, and human waste sludge. A step of kneading sludge, a first powder having an average particle size of 500 μm or less, and a second powder having an average particle size of 1 mm or more to obtain a kneaded product.
The firing process to manufacture cement clinker by firing the raw material of cement clinker,
A reduction step of reducing the water content of the kneaded product by fermenting the kneaded product, which is performed prior to the firing step,
With
A method for producing cement clinker, in which the kneaded product is put into the firing step. The method for producing cement clinker according to claim 6 , wherein in the firing step, the kneaded product is put into at least one place of a preheater, a calcining furnace, and a kiln tail of a kiln and burned. The method for producing a cement clinker according to claim 6 or 7 , wherein the first powder is at least one selected from the group consisting of toner, wheat powder, polymer powder, plastic powder, shavings and metal powder. The method for producing cement clinker according to any one of claims 6 to 8 , wherein the second powder is at least one of plastic powder and wood powder. The method for producing a cement clinker according to any one of claims 6 to 9 , wherein the sludge is at least one selected from the group consisting of sewage sludge, industrial wastewater sludge, and human waste sludge. A step of manufacturing a cement clinker by the method for manufacturing a cement clinker according to any one of claims 6 to 10.
The process of manufacturing cement from the cement clinker and
A method of manufacturing cement.

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