JPH0576987B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing highly concentrated coal-water slurry for improving the properties of the slurry.

[Conventional technology]

High concentration coal water slurry is finely ground coal 60~
It is a mixture of 90% by weight and 10-40% by weight of water with some additives, and is a fluid fuel that can be burned as is in a boiler etc. without dehydration, and it converts coal, which is a solid fuel, into a fluid. This dramatically expands the scope of use. In addition, the coal water slurry will be simply abbreviated as slurry below.

Conventionally, methods for producing high-concentration slurry can be roughly divided into three types: dry method, high-concentration wet method, and low-concentration wet method.

In the dry method, coal is pulverized in air using a mill, and then mixed and stirred (hereinafter referred to as mixing and stirring) with water and additives to form a highly concentrated slurry.

Further, in the high concentration wet method, coal, water and additives are simultaneously charged into a tube mill, and pulverization and mixing and stirring are performed simultaneously.

Furthermore, the low concentration wet method involves putting coal and water into a tube mill and pulverizing it at a low concentration.
After forming a low concentration slurry of 20 to 60% by weight and 40 to 80% by weight of water, this is dehydrated in a dehydrator to form a dehydrated cake, which is then mixed together with a small amount of adjusted water and additives in a mixer. It is stirred to form a highly concentrated slurry.

What is illustrated in FIG. 11 is a flow sheet relating to a conventional method for producing a low-concentration wet high-concentration slurry.

In FIG. 11, a is a storage tank for supplying coal;
b is a coal supply line, c is a tank for mill supply water, d is a mill supply water supply line, e is a wet mill, f is a transport line for the low concentration slurry obtained in the wet mill e, and g is a dehydrator. , h is a drainage line for dehydrated water obtained by dehydration in dehydrator g, i is a transport line for slurry obtained by dehydration in dehydrator g (hereinafter referred to as dehydrated cake), j is a mixing agitator, k is a mixing agitator
A tank for adjusting water is supplied through a supply line l of adjusted water, m is a tank for additives supplying additives to a mixing agitator j through a supply line n, and o is a tank for supplying the adjusted water to the mixing agitator j through a supply line n. Concentrated slurry transportation line,
p is a combustion means (hereinafter referred to as a product slurry tank) such as a storage tank or a boiler for the highly concentrated slurry that is the product.

In such a flow sheet, the storage tank a
Coal and mill supply water are supplied from tank c to wet mill e through lines b and d, and coarsely pulverized at a low concentration to produce a low concentration slurry. This low concentration slurry is supplied to the dehydrator g via line f. In the dehydrator g, the low concentration slurry is dehydrated, the dehydrated water is drained from the line h, and the dehydrated cake is supplied to the mixer j through the line i. In this mixer j, the supplied dehydrated cake is mixed and stirred with the conditioning water and additives supplied from tanks k and m through lines l and n to form a highly concentrated slurry with low viscosity, and the resulting product is made into a highly concentrated slurry with low viscosity. The slurry is supplied from the high concentration slurry line o to the product slurry tank p.

[Problems to be Solved by the Invention] In such a conventional method for producing a high concentration slurry using a low concentration wet method, the line o is
The highly concentrated slurry that comes out as a product is prepared by coarsely pulverizing and dehydrating coal in a wet mill and then supplying conditioning water and additives, which causes the following problems. Ta.

(b) Since the additives were still being mixed and stirred, the additives were not evenly dispersed in the product slurry, and the quality of the product slurry was uneven.

(b) The highly concentrated slurry that comes out as a product from the mixer j through the line o is obtained by only coarsely pulverizing the coal in the wet mill e, so the shape of the coal particles is angular. When mixed with the additive and stirred, the additive was not well dispersed. For this reason, the effects of the additives could not be fully exhibited, and a highly concentrated slurry with low viscosity could not be obtained.

As described above, in the conventional low-concentration wet method for producing high-concentration slurry, there is a problem in that the high-concentration slurry that comes out as a product from mixer j through line o has variations, that is, uniformity in quality. As a result, when used in a boiler or the like, there was a possibility that the combustion state would be inconsistent.

The present invention is provided for the purpose of solving the problems of the conventional low-concentration wet high-concentration slurry manufacturing method described above and obtaining a high-quality high-concentration slurry with low viscosity and uniformity.

[Means for solving problems]

The first aspect of the present invention is to coarsely pulverize coal in water to create a low-concentration slurry, then dehydrate the low-concentration slurry, lead the resulting dehydrated cake to a mixer, and feed it with the mixer. The adjusted water, additives, and the dehydrated cake are mixed and stirred together with the returned adjusted slurry to create a kneaded high-concentration slurry, and the kneaded high-concentration slurry is further led to a dispersion machine, where the above-mentioned additives are mixed with the above-mentioned additives. Uniformly dispersed in the kneaded high-concentration slurry, the obtained dispersed high-concentration slurry is further adjusted in a slurry adjustment tank and supplied as a product, and a part of the adjusted high-concentration slurry is returned as is to the mixing agitator for circulation. This is a method for producing a highly concentrated slurry, which is characterized by:

[Effect]

Coal and water are supplied to a coarse grinding mill for coarse grinding to produce a low concentration slurry with a high moisture content. This low-concentration slurry has a high water content, so if left as it is, it will adversely affect the combustion efficiency in a boiler or the like, and it is dehydrated in order to equalize the water concentration of the slurry obtained in a mixing agitator. The dehydrated cake obtained by this dehydration is introduced into a mixing agitator. In the mixer, the adjusted water for adjusting the water concentration of the slurry, the additives, and the above-mentioned dehydrated cake are mixed and stirred together with the returned adjusted slurry to obtain a high-concentration slurry. This kneaded high-concentration slurry is fed into a dispersing machine and subjected to high-speed shearing to uniformly disperse the additives in the kneaded high-concentration slurry. Next, this dispersed high-concentration slurry is sent to a slurry conditioning tank and adjusted to obtain a high-quality adjusted high-concentration slurry with low viscosity and uniformity. While this adjusted high-concentration slurry is supplied as a product, a portion of it is returned as is to the mixing agitator to produce a more uniform and high-quality product.

〔Example〕

A preferred embodiment of the first aspect of the present invention will be described in detail with reference to the embodiment illustrated in FIG.

The embodiment illustrated in FIG. 1 is a flow sheet of the embodiment according to the first invention.

In Figure 1, 1 is a coal supply storage tank, 2 is a coal supply line, 3 is a tank for coarse grinding wet mill supply water, and 4 is coarse grinding wet mill supply water (hereinafter referred to as coarse grinding mill supply water). 5 is a coarse grinding wet mill (hereinafter referred to as coarse grinding mill); 6 is a transport line for the low concentration slurry obtained by the coarse grinding mill 5;
7 is a dehydrator, 8 is a drainage line for the dehydrated water obtained in the dehydrator 7, 9 is a transport line for the dehydrated cake obtained in the dehydrator 7, 10 is a mixing agitator, and 11 is the water concentration of the slurry in the mixing agitator 10. 12 is a supply line for the adjusted water, and 13 is an additive such as a surfactant (hereinafter referred to as added) to be supplied to the mixing agitator 10. (hereinafter referred to as additive tank), 14 is an additive supply line;
15 is a transportation line for the kneaded high-concentration slurry mixed and kneaded by the mixer 10, 16 is a dispersion machine such as a line mixer, and 17 is a dispersion machine 16 that applies high-speed shear to the slurry in the machine so that the additives are uniformly distributed. Transportation line for the dispersed high concentration slurry obtained by dispersion, 1
8 is a slurry adjustment tank, 19 is a transport line for the adjusted high concentration slurry whose concentration variation is further made uniform in the slurry adjustment tank 18, and 20 is 1 for the adjusted high concentration slurry.
21 is a transport line for high-quality high-concentration slurry (hereinafter referred to as product high-concentration slurry) to be supplied as a product or to the next process; 22 is a line for transporting high-quality high-concentration slurry (hereinafter referred to as product high-concentration slurry); Tank for storing high-concentration product slurry to be supplied to the next process (hereinafter referred to as tank for high-concentration product slurry)
It is. Note that the line 21 may be directly connected to a combustion means such as a boiler (not shown), but a description of this will be omitted since it is the same below. Note that necessary transport pumps and the like are omitted in this flow sheet.

In such an embodiment illustrated in FIG.
The coal in the coal storage tank 1 and the coarse grinding mill feed water in the feed water tank 3 are supplied to the coarse grinding mill 5 via lines 2 and 4, and coarsely ground at a low concentration to produce a low concentration of coal of 20 to 60% by weight. Make slurry. This low concentration slurry is supplied to a dehydrator 7 via line 6. and,
The dehydrated water produced by the dehydration in the dehydrator 7 is discharged from the line 8, while the dehydrated cake is supplied to the mixer 10 via the line 9. In the mixer 10, a dehydrated cake, adjusted water supplied from an adjusted water tank 11 through a line 12 to adjust the water concentration of the slurry, and additives supplied from an additive tank 13 through a line 14. and return circulation line 20
The returned adjusted slurry is mixed and stirred together and adjusted to an appropriate concentration. The mixed high-concentration slurry obtained by mixing and stirring with the mixer 10 is fed through a line 15 to a dispersing machine 16 and subjected to high-speed shearing to uniformly disperse the additives into the kneaded high-concentration slurry. Next, this dispersed high-concentration slurry is sent to the slurry adjustment tank 18 and adjusted to obtain a high-quality adjusted high-concentration slurry with low viscosity and uniformity. The adjusted high concentration slurry obtained from the slurry adjustment tank 18 is sent to the line 19,
The adjusted high concentration slurry is returned and circulated to the mixer agitator 10 via a return circulation line 19. As mentioned above, the mixing agitator 10 is used to prepare a dehydrated cake, adjust water,
By mixing and stirring together with additives, a high-quality kneaded high-concentration slurry with low viscosity and uniformity is obtained. This high-quality kneaded high-concentration slurry is dispersed in the dispersion machine 16 and adjusted in the slurry adjustment tank 18 as described above, and then one part is returned to the line 20, and the other adjusted high-concentration slurry is sent to the line 20 as a product high-concentration slurry. From there, the product is transported to a tank 22 for high-concentration product slurry and stored there.

As described above in detail based on the flow sheet of FIG. 1 showing the embodiment according to the first invention, the following effects can be obtained by the first invention.

〔Effect of the invention〕

(1) Since the coarse grinding mill performs grinding at a low concentration (20 to 60% by weight of coal) where the grinding power is minimum, it can be operated at the point where the grinding power is minimum.

(2) The kneaded high-concentration slurry obtained with the mixing agitator is dispersed in a disperser and then adjusted in a slurry adjustment tank (hereinafter abbreviated as "kneading → dispersion → adjustment").
Therefore, since the additives are uniformly dispersed in the slurry and the concentration is extremely uniform, it is possible to obtain a high-quality, homogenized product and a high-concentration slurry.

(3) A portion of the high-quality, homogenized, adjusted high-concentration slurry that has been “kneaded → dispersed → adjusted” is returned to the mixer and circulated, resulting in an even product. Moreover, a high concentration product slurry having a predetermined quality can be quickly obtained at the time of plant start-up.

(4) Since the coal is coarsely pulverized in a coarse pulverizing mill and then dehydrated, the dehydration performance of the dehydrator is significantly improved, and the water content in the dehydrated cake is reduced, making it possible to reduce the water content of the subsequent high-concentration slurry. I can hold it down. Further, the adjusted concentration of water can be selected from a wide range.

Next, broken lines and dashed-dotted lines will be explained as additions to the flosheat of the first embodiment of the present invention.

A broken line 23 is a line for returning the dehydrated water discharged from the line 8 obtained by the dehydrator 7 to be used as water to be supplied to the coarse grinding mill 5. Also,
A dashed line 24 is a line through which dehydrated water obtained by the dehydrator 7 and discharged from the line is fed to the adjusted water tank 11 so as to be used as adjusted water to be supplied to the mixing agitator 10.

The lines 23 and 24 can be set to only the line 23, only the line 24, or only the line 2, depending on the need.
3. Both of the lines 24 may be used at the same time, or, although not shown, the disperser 16, the slurry adjustment tank 18, and the lines may be connected to make effective use of dehydrated water.

The following effects can be obtained by the embodiment in which the lines 23 and/or the lines 24 are provided in this manner.

Since the dehydrated water contains colloidal ultrafine coal particles, these are fed to the coarse grinding mill 5 and coarsely ground together with the supplied coal and water.
The pseudoplasticity of the high-concentration product slurry increases and the storage stability improves.

Since the dehydrated water contains colloidal ultrafine coal particles, this is fed to the mixer 10 and mixed and stirred together with the contents in the mixer 10, so that rheologin properties become even more pseudoplastic, making it extremely difficult to store. A highly stable and highly concentrated slurry can be obtained.

Note that the functions and effects of lines 23 and 24 are similar in the following embodiments, so explanations regarding each embodiment will be omitted.

Next, a second invention of the present invention has been submitted to further improve the first invention.

That is, the feature of the second invention is that in the first invention, the dehydrated cake obtained from the dehydrator is crushed into fine dehydrated cakes by a crushing device before being led to the mixing agitator.

Hereinafter, a preferred embodiment of the second aspect of the present invention will be described in detail with reference to the embodiment illustrated in FIG.

The embodiment illustrated in FIG. 2 is a flow sheet of the embodiment according to the second invention.

In the embodiment shown in FIG. 2, reference numerals 1 to 24 are equivalent to reference numerals 1 to 24 in the embodiment shown in FIG. 1, so their explanation will be omitted. Reference numeral 25 denotes a crushing device, which crushes the plate-shaped or block-shaped dehydrated cake supplied via the line 9 into small or small chunks. Reference numeral 26 denotes a line for transporting the dehydrated cake in the form of small or minute lumps (hereinafter referred to as small dehydrated cake).

The embodiment shown in FIG. 2 is different from the embodiment shown in FIG.
5, the plate-shaped or lump-like dehydrated cake is crushed into small lumps or minute lumps to form a small lump-like dehydrated cake, and this is supplied to the mixing agitator 10 via the small lump-like dehydrated cake line 26. be.

As described above in detail based on the flow sheet of FIG. 2 showing the embodiment according to the second invention, the second invention
The invention provides the following effects in addition to the effects described in (1) to (4) above obtained with the first invention.

(5) In order to crush the dehydrated cake into small pieces and supply it to the mixing agitator, the slurry supplied to the mixing agitator is uniformly mixed with adjusted water, additives, and returned adjusted slurry for mixing and stirring. Mixing, agitation, and adjustment go smoothly, allowing you to obtain a high-quality, uniform, high-concentration product slurry.

(6) Furthermore, since homogeneous mixing can be achieved smoothly, the amount of product high-concentration slurry produced per unit time is significantly increased, and productivity is therefore improved.

Next, a third invention of the present invention is provided to further improve the first invention.

That is, the feature of the third invention is that in the first invention, the low concentration slurry obtained from the coarse grinding mill is classified into coarse particle-containing low concentration slurry and coarse cut low concentration slurry using a classifier, and the coarse cut low concentration slurry is divided into coarse cut low concentration slurry. The purpose of this is to guide only the water to the dehydrator.

Hereinafter, a preferred embodiment of the third aspect of the present invention will be described in detail with reference to the embodiment illustrated in FIGS. 3 and 4.

The embodiments illustrated in FIGS. 3 and 4 are flow sheets of the first embodiment and the second embodiment according to the third invention.

In the embodiment illustrated in FIGS. 3 and 4,
The same reference numerals among the reference numerals 1 to 24 are equivalent to the same reference numerals among the reference numerals 1 to 24 in the embodiment shown in FIG. 1, so the explanation thereof will be omitted. 9a is a transportation line for the coarse cut dehydrated cake, and 27 is a classification for separating the coarse particles in the low concentration slurry supplied from line 6 and classifying the coarse particles into a coarse particle-containing low concentration slurry and a coarse cut cut low concentration slurry. vessel, 28
29 is a discharge line for the coarse grain-containing low concentration slurry classified by the classifier 27, and 29 is a transport line for the coarse grain cut low concentration slurry classified by the classifier 27.

Such an embodiment as shown in FIG. 3 is similar to the case of the embodiment shown in FIG.
The low concentration slurry obtained is supplied to the classifier 27 via line 6 to be classified into low concentration slurry containing coarse particles and coarse cut low concentration slurry, and only the coarse cut low concentration slurry is sent to the dehydrator through line 29. The feature is that it supplies to 7.

As described above in detail based on the flow sheet of FIG. 3 showing the first embodiment according to the third invention,
The invention provides the following effects in addition to the effects described in (1) to (6) above obtained with the first invention.

(7) Since only coarse particles are classified using a classifier and only the low concentration slurry of coarse particles is supplied to the product manufacturing line, there are very few coarse particles in the product high concentration slurry and the number of fine or ultra-fine coal particles increases. As a result, the rheological properties of the high-concentration product slurry become pseudoplastic, improving storage stability.

(8) Since classification is performed using a classifier, the maximum diameter of the coarse particles in the highly concentrated product slurry can be arbitrarily selected. Therefore, it becomes easier to obtain a product-rich slurry with a desired particle size distribution.

(9) Since the product is classified using a classifier and only the coarse cut, low-concentration slurry is supplied to the product manufacturing line, the amount of coarse particles in the high-concentration product slurry is extremely reduced. Therefore, when the coal is combusted in a combustion means such as a boiler, the amount of unburned coal is extremely reduced, the residue inside the boiler is almost eliminated, and the combustion efficiency is improved.

Further, FIG. 4 shows a second embodiment of the third invention,
The coarse particle-containing low concentration slurry obtained in the classifier 27 is returned to the coarse particle crushing mill 5 via the coarse particle containing low concentration slurry return circulation line 28a, and the contained coarse particles are further passed through the coarse particle crushing mill 5. It is used to crush coal into fine or minute coal particles.

In this way, the second invention of the third invention illustrated in FIG.
In the embodiment, the following effects can be further obtained.

Since the coarse particle-containing low concentration slurry is again coarsely pulverized by the coarse grinding mill 5, the coarse particles in the product high concentration slurry become even smaller, while the fine and ultrafine coal particles increase, resulting in a product with high concentration. The rheological properties of the slurry become very pseudoplastic and the storage stability is improved.

Since the coarse particle-containing low-concentration slurry is classified by the classifier 27 and ground again by the coarse grinding mill 5, the maximum diameter of the coarse particles in the product high-concentration slurry can be selected very arbitrarily. Therefore, it becomes extremely easy to obtain a highly concentrated product slurry with a desired particle size distribution.

Since the low concentration slurry containing coarse particles is classified by the classifier 27 and crushed again by the coarse grinding mill 5, the amount of coarse particles in the product high concentration slurry is extremely reduced.

Therefore, when the coal is combusted in a combustion means such as a boiler, the amount of unburned coal is significantly reduced, the amount of residue in the boiler is also significantly reduced, and the combustion efficiency is further improved.

Next, the fourth invention of the present invention is provided for the purpose of achieving a synergistic effect of the effects of the second and third inventions of the present invention to obtain a high-concentration slurry of even better quality.

In other words, the feature of the fourth invention is the second invention and the third invention.
In the invention, before introducing the low concentration slurry obtained from the coarse grinding mill to the dehydrator, it is classified into coarse particle-containing low concentration slurry and coarse cut low concentration slurry using a classifier, and only the coarse cut low concentration slurry is sent to the dehydrator. and to crush fine dehydrated cakes with a crusher before introducing the coarse cut dehydrated cakes obtained from the dehydrator to a mixing agitator.

Hereinafter, a preferred embodiment of the fourth aspect of the present invention will be described in detail with reference to the embodiment illustrated in FIGS. 5 and 6.

The embodiments illustrated in FIGS. 5 and 6 are flow sheets of the first embodiment and the second embodiment according to the fourth invention.

In the embodiment illustrated in FIGS. 5 and 6,
Those with the same numbers among numerals 1 to 29 are numerals 1 to 2 in the embodiments illustrated in FIGS. 1 to 4.
Since it is equivalent to the one with the same symbol in 9, the explanation will be omitted. Note that 9a is a transportation line for the coarse cut dehydrated cake, and 26a is a transportation line for the coarse cut dehydrated cake in the form of small blocks.

In the embodiment shown in FIG. 5, in the case of the embodiments shown in FIGS. The slurry is separated into a low concentration slurry containing coarse particles and a low concentration slurry containing coarse cut cuts, and only the coarse cut low concentration slurry is sent from line 29 to dehydrator 7.
The coarse cut dehydrated cake obtained by the dehydrator 7 is fed to the crusher 25 through a line 9a.
It is characterized in that the plate-shaped or lump-like dehydrated cake is crushed into small lumps or minute lumps to form a small lump-like dehydrated cake, and this is fed to the mixer agitator 10 via the line 26a.

As described above in detail based on the flow sheet of FIG. 5 showing the embodiment according to the fourth invention, the fourth invention achieves the above (1) and above obtained by the first invention to the third invention.
In addition to the effects described in (10), the following effects can be obtained.

(11) Classify before dehydration, dehydrate only the coarse cut low concentration slurry, and further crush the plate-shaped or block-shaped coarse cut dehydrated cake after dehydration into small lumps using a crusher and mixer. In addition, in the mixing agitator, the adjusted high concentration slurry is constantly returned and circulated and mixed and stirred together to create a good kneading state.The synergistic effect of these makes it possible to produce extremely high quality product high concentration slurry. Obtainable.

FIG. 6 shows a second embodiment of the fourth invention, and the first embodiment of the fourth invention illustrated in FIG.
By adding the configuration and operation described in the flow sheet of FIG. 4 illustrating the second embodiment of the third invention,
In addition to the effects described above, the following effects are aimed at.

The low concentration slurry containing coarse particles is classified before dehydration and is returned to the coarse grinding mill 5 to be crushed again, only the coarse cut low concentration slurry is dehydrated, and the coarse cut cut dehydrated cake is further dehydrated in the form of plates or blocks after dehydration. In order to crush the slurry into small pieces in the agglomeration device 25 and supply it to the mixer agitator 10, the mixer agitator 10 always returns the adjusted high-concentration slurry adjusted in the slurry adjustment tank 18. Since these ingredients are mixed and stirred to form a good kneading state, the synergistic effect of these makes it possible to easily obtain a highly concentrated product slurry of extremely high quality. Next, the fifth invention of the present invention is a further improvement of the third invention of the present invention.

That is, the feature of the fifth invention is that in the third invention, the low concentration slurry obtained from the coarse grinding mill is diluted with dilution water before being led to the classifier, and then this diluted low concentration slurry is led to the classifier. .

Hereinafter, a preferred embodiment of the fifth aspect of the present invention will be described with reference to the embodiment illustrated in FIGS. 7 and 8.

The embodiments illustrated in FIGS. 7 and 8 are flow sheets of the first embodiment and the second embodiment according to the fifth invention.

In the embodiment illustrated in FIGS. 7 and 8,
The same numbers among the reference numerals 1 to 29 are the reference numerals 1 to 29 in the embodiments illustrated in FIGS. 1 to 6.
Since these are equivalent to those with the same reference numerals, their explanation will be omitted. Further, 9a is a transport line for the coarse cut dehydrated cake, 28b is a discharge line for the coarse grain-containing diluted low concentration slurry, 29a is a transport line for the coarse cut diluted low concentration slurry, and 30 is supplied via the line 6. A dilution tank 31 dilutes the low concentration slurry to a concentration that is easy to classify with dilution water, 31 is a dilution water tank, 32 is a dilution water supply line that supplies dilution water from the dilution water tank 31, and 33 is a dilution tank 30. Coal obtained by dilution 15-40% by weight, water
This line transports 60 to 85% by weight low concentration slurry (hereinafter referred to as diluted low concentration slurry).

Such an embodiment as illustrated in FIG. 7 is similar to the case of the embodiment illustrated in FIG.
The low concentration slurry obtained is led to a dilution tank 30 through a line 6, and is diluted in this dilution tank 30 with dilution water supplied from a tank 31 through a line 32 to a concentration that is easy to classify. That is, it is made into a diluted low concentration slurry containing 15 to 40% by weight of coal. This diluted concentration slurry is passed through a line 33 to a classifier 27.
The slurry is divided into a diluted low-concentration slurry containing coarse particles and a diluted low-concentration slurry containing coarse particles. The feature is that this coarse cut diluted low concentration slurry is supplied to the dehydrator 7 from the line 29a.

Further, FIG. 8 shows a second embodiment of the fifth invention,
Return circulation line 2 for the diluted low concentration slurry containing coarse particles obtained in the classifier 27
The coal is sent back to the coarse pulverizing mill 5 via 8c, and the contained coarse particles are further pulverized into fine or fine coal particles by the coarse pulverizing mill 5.

As described above in detail based on the flow sheets of FIGS. 7 and 8 showing the embodiments of the fifth invention, the fifth invention is the above (1) to (12) obtained in the first invention and the third invention. In addition to the effects described in ), the following effects can be obtained.

(13) Since the low concentration slurry of 20 to 60% by weight of coal is diluted to a thin diluted low concentration slurry of 15 to 40% by weight of coal before being classified by the classifier, the classification efficiency in the classifier is improved. Mass production of highly concentrated product slurry is possible.

Next, the sixth invention of the present invention is a further improvement of the first invention to the fifth invention.

That is, the feature of the sixth invention is that in the fifth invention, the coarse cut dehydrated cake obtained from the dehydrator is crushed into fine dehydrated cakes by the crushing device before being led to the mixing agitator.

Hereinafter, a preferred embodiment of the sixth aspect of the present invention will be described in detail with reference to the embodiment illustrated in FIGS. 9 and 10.

The embodiment illustrated in FIG. 9 and FIG.
1 is a flow sheet of a first embodiment and a second embodiment according to the invention.

In the embodiment shown in FIGS. 9 and 10, the same numbers among the reference numerals 1 to 33 and reference numerals 9a, 26a, 28b, 28c, and 29a are used in the embodiment shown in FIGS. 7 and 8. 1 to 33 with the same numbers and codes 9a, 26a,
Since they are equivalent to 28b, 28c, and 29a, their explanation will be omitted.

In the embodiment shown in FIG. 9, in the case of the embodiment shown in FIG. 7, the coarse cut dehydrated cake obtained in the dehydrator 7 is fed to the crushing device 25 via the line 9a, and is crushed into plate shapes. Alternatively, the dehydrated cake in the form of a lump is crushed into a small lump or a fine lump to form a small coarse cut dehydrated cake, which is then supplied to the mixer agitator 10 via the line 26a.

As described above in detail based on the flow sheet of FIG. 9 showing the embodiment according to the sixth invention, the sixth invention achieves the above (1) and above obtained by the first invention to the fifth invention.
In addition to the effects described in (13), the following effects can be obtained.

(14) Dilute to make it easier to classify before classification, cut coarse grains by classification, dehydrate only the coarse grain cut diluted low concentration slurry, and then form plate-shaped or lump-like coarse grains after dehydration. In order to crush the cut dehydrated cake into small pieces using a crusher and feed it to the mixer, the mixer also constantly returns and circulates the adjusted high concentration slurry, which is then mixed and stirred together to produce a good quality product. Once the mixture is in a kneaded state, the synergistic effect of these makes it possible to obtain a highly concentrated product slurry of extremely high quality.

Moreover, FIG. 10 is a second embodiment of the sixth invention, and the first embodiment of the sixth invention illustrated in FIG.
By adding the configuration and operation described in the flow sheet of FIG. 8 illustrating the second embodiment of the fifth invention,
In addition to the effects described above, the following effects are aimed at.

Before classification, the diluted slurry is diluted to make it easier to classify, and the coarse particles are cut through the classification, and the diluted low concentration slurry containing coarse particles is returned to the coarse grinding mill 5 and crushed again. In order to dehydrate only the concentrated slurry, and further crush the plate-shaped or lump-like coarse cut dehydrated cake after dehydration into small chunks in the crushing device 25 and supply it to the mixer agitator 10,
In the mixer agitator 10, the returned and adjusted high concentration slurry is constantly returned and circulated and mixed and stirred together to form a good kneading state, so the synergistic effect of these makes it possible to obtain a very high quality product high concentration slurry. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a flow sheet of the first embodiment according to the first invention of the present invention, FIG. 2 is a flow sheet of the first embodiment according to the second invention, and FIG. 3 is a flow sheet of the first embodiment according to the third invention. , FIG. 4 is a flow sheet of the second embodiment according to the third invention, FIG. 5 is a flow sheet of the first embodiment according to the fourth invention, and FIG.
The figure is a flow sheet of the second embodiment according to the fourth invention, FIG. 7 is the flow sheet of the first embodiment according to the fifth invention, FIG. 8 is the flow sheet of the second embodiment according to the fifth invention, and FIG. 9 is the flow sheet of the second embodiment according to the fifth invention. FIG. 10 is a flow sheet for the first embodiment according to the sixth invention, FIG. 10 is a flow sheet for the second embodiment according to the sixth invention, and FIG. 11 is a flow sheet for a conventional method for manufacturing low concentration wet high concentration slurry. 1...Coal supply storage tank, 2...Coal supply line, 3...Coarse grinding mill supply water tank, 4...
Coarse grinding mill supply water supply line, 5... Coarse grinding mill, 6... Low concentration slurry transportation line, 7... Dehydrator, 8... Dehydrated water discharge line, 9... Dehydrated cake transportation line, 9a... Transportation line for coarse cut dehydrated cake, 10... Mixing agitator, 11...
Adjustment water tank, 12...Adjustment water supply line,
13...Additive tank, 14...Additive supply line, 15...Transportation line for kneaded high concentration slurry, 16...Dispersion machine, 17...Transportation line for dispersed high concentration slurry, 18...Slurry adjustment Tank, 19...
Transportation line for adjusted high concentration slurry, 20...Return circulation line for returned adjusted high concentration slurry, 21...Transportation line for product high concentration slurry, 22...Tank for product high concentration slurry, 23...Return circulation for dehydrated water line, 24... dehydrated water supply line, 25... agglomeration device, 26... small lump dehydrated cake transport line,
26a...Transportation line for small-sized coarse cut dehydrated cake, 27...Classifier, 28...Discharge line for low concentration slurry containing coarse particles, 28a...Return circulation line for low concentration slurry containing coarse particles, 28b... Discharge line for diluted low concentration slurry containing coarse particles, 28c...Return circulation line for diluted low concentration slurry containing coarse particles, 29...
Transportation line for coarse cut and low concentration slurry, 29a...
...Transportation line for coarse cut diluted low concentration slurry, 3
0... Tank for dilution, 31... Tank for dilution water,
32... Dilution water supply line, 33... Diluted low concentration slurry transport line.

Claims (1)

[Claims] 1. Coarsely pulverized coal in water to create a low concentration coal water slurry, then dewatering the low concentration coal water slurry, leading the obtained dehydrated cake to a mixing agitator, and adding adjusted water supplied by the mixing agitator. , mix and stir with additives to create a kneaded high-concentration coal-water slurry,
Furthermore, the above-mentioned kneaded high-concentration coal-water slurry is led to a dispersion machine, and the above-mentioned additives are uniformly dispersed in the above-mentioned kneaded high-concentration coal-water slurry by the same dispersion machine, and the obtained dispersed high-concentration coal-water slurry is further transferred to a slurry adjustment tank. A method for producing a highly concentrated coal-water slurry, characterized by adjusting the slurry in