JPS60235895A - Production of highly concentrated coal/water slurry - Google Patents

Abstract

PURPOSE:To produce the titled slurry which has a low viscosity and is excellent in unformity, by dehydrating a low-concn. coal/water slurry, adding adjusting water, additives and a highly concentrated returned aged coal/water slurry to the dehydrated cake and aging the mixture. CONSTITUTION:Coal in a reservoir 1 and feed water in a tank 3 are fed through lines 2, 4 to a wet-process mill 5 and crushed to obtain a coal/water slurry contg. coal at a low concn. of 20-60wt%. The slurry is dehydrated in a dehydrator 7 and the dehydrated cake is fed to a controlling tank 10 where adjusting water, additives fed through lines 12, 14 from tanks 11, 13 and a highly concentrated aged coal/water slurry returned through a line 18 are mixed with the cake. The mixture is fed to an aging device 16 where it is stirred and aged to obtain a highly concentrated aged coal/water slurry. Part of the slurry is returned to the controlling tank 10, and the remainder is fed to a tank 20 and stored as a product.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a highly concentrated coal water slurry with good slurry properties.

High-concentration coal water slurry (hereinafter referred to as high-concentration slurry) is a mixture of 60-90% by weight of finely pulverized coal and 40-10% by weight of water, with some additives added, and can be left as is without dehydration. It is a fluid fuel that can be combusted in boilers, etc., and its range of use can be dramatically expanded by turning solid fuel coal into a fluid.

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

The dry method uses a mill to pulverize coal in the air, and then mixes and stirs it with water and additives (hereinafter referred to as mixing and stirring) to form a highly concentrated slurry.

In addition, the high concentration wet method uses coal in a tube mill.

Water and additives are added at the same time, and pulverization and mixing and stirring are performed at the same time.

Furthermore, in the low concentration wet method, coal and mill supply water are put into a tube mill and pulverized at a low concentration.
After making a low concentration coal water slurry (hereinafter referred to as low concentration slurry) containing 60% by weight of coal and 40 to 80% by weight of water, this is dehydrated in a dehydrator to form a dehydrated cake, which is then rehydrated in a small amount in a mixing agitator. Adjustment water and additives are mixed and stirred together to form a high concentration slurry IJ-.

What is illustrated in FIG. 1 is a flow sheet relating to a conventional method for producing a low concentration wet high concentration slurry.

In FIG. 1, a storage tank for supplying coal.

b is the coal supply line, C is the tank for mill supply water, d
is the mill feed water supply line, e is the wet mill, and f is the low concentration obtained in the wet mill e.

The slurry transport line g is a dehydrator, and the dehydrator g dehydrates low concentration slurry. hb A line to drain the dehydrated water obtained by dewatering with dehydrator g, i is dehydrator g
Slurry obtained by dehydration (hereinafter referred to as dehydrated cake)
J is a mixing agitator; is a tank for conditioning water that supplies conditioning water to the mixing agitator j via a conditioning water supply line 1; m is a tank for supplying conditioning water to the mixing agitator j via an additive supply line n; 0 is a transportation line for the high concentration slurry that is the product, a storage tank for the high concentration slurry that is the p#'i product, a boiler combustion means, etc. (hereinafter referred to as the tank for product slurry) It is.

In such a flow sheet, coal and mill supply water are supplied from storage tank a and tank C to wet mill e through lines b and d, and are pulverized at a low concentration to create 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. This mixer J mixes and stirs the supplied dehydrated cake with the adjustment water and additives supplied to the tank and from m through lines 1 and n to form a highly concentrated slurry with low viscosity. The product is supplied from the high concentration slurry line O to the product slurry tank p.

In such a conventional method for producing a low-concentration wet high-concentration slurry, there is a problem in that the high-concentration slurry that comes out as a product from the mixer J through line 0 has variations, that is, uniformity of 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 intended to solve the problems of the conventional low-concentration wet high-concentration slurry manufacturing method described above and to obtain a high-quality high-concentration slurry with low viscosity and uniformity.

That is, the first aspect of the present invention is to wet-pulverize coal in water using a wet mill to prepare a low-concentration slurry, then dehydrate the low-concentration slurry to form a dehydrated cake, and introduce the dehydrated cake to a slurry adjustment tank. Adjusted water and additives are supplied and mixed with the uniformly returned matured high concentration slurry to create an adjusted high concentration slurry, and the adjusted high concentration slurry is further stirred in a maturing machine to make it uniform. This is a method for producing a highly concentrated coal water slurry, which is characterized in that the slurry is aged into a matured highly concentrated slurry with a certain property and then supplied as a product, and a part of the matured highly concentrated slurry is circulated back to the slurry adjustment tank.

Hereinafter, two preferred embodiments of the first aspect of the present invention will be described in detail with reference to the embodiments illustrated in FIGS. 2 and 3.

The embodiment illustrated in FIG. 2 is a flow seay-1 of the first embodiment according to the first invention.

In FIG. 2, the lVi coal supply reservoir.

2 is a coal supply line, 3 is a tank for mill supply water, 4 is
5 is a mill supply water supply line, 5Vi wet mill, 6 is a transport line for the low concentration slurry obtained by wet mill 5, 7 is a dehydrator, and the dehydrator 7 dehydrates the low concentration slurry to form a dehydrated cake. It is something. 8 is a drainage line for the de-iced water obtained by the dehydrator 7, 9 is a transport line for the dehydrated cake obtained by dehydrating in the dehydrator 7, 10 is a slurry adjustment tank or mixing agitator (hereinafter referred to as the slurry adjustment tank), 11 is a storage number for water supplied to adjust the water concentration of the slurry in the slurry adjustment tank 10 (hereinafter referred to as adjustment water).

12 is a regulated water supply line; 13 is a regulated water tank;
1 is a tank (hereinafter referred to as an additive tank) for storing additives such as surfactants (hereinafter referred to as additives) to be supplied to the slurry adjustment tank 10; 14 is an additive supply line; 1
5 is a high concentration slurry (
16 is a maturing machine such as a line mixer (hereinafter abbreviated as maturing machine);
17 is a transport line for uniform, high-concentration slurry (hereinafter referred to as aged high-concentration slurry) that has been stirred and aged in the ripening machine 16, and 18 is a part of the aged high-concentration slurry (hereinafter referred to as return aged high-concentration slurry). A return circulation line that returns and circulates slurry (denoted as slurry).

Reference numeral 19 denotes a transportation line for high-quality matured high-concentration slurry (hereinafter referred to as product high-concentration slurry) to be supplied as a product or to the next process, and 20 is a tank for storing the product high-concentration slurry to be supplied as a product or to the next process ( (hereinafter referred to as tank for product high concentration slurry).

Note that the line 19 may be connected to a boiler combustion means or the like (not shown), but the explanation regarding this will be omitted since it is the same below.

In such an embodiment as illustrated in FIG. 2, the coal in the coal storage tank 1 and the mill feed water in the feed water tank 3 are fed to the wet mill 5 via lines 2 and 4 and are ground to a low concentration. A low concentration slurry containing 20-60% by weight of coal is made.

This low concentration slurry is supplied to a dehydrator 7 through a line 6, and the dehydrated water produced by dehydration is discharged through a line 8, while the dehydrated cake is supplied through a line 9 to a slurry adjustment tank 10. In the slurry adjustment tank 10, there is a dehydrated cake, adjustment water supplied via a line 12 from a adjustment water tank 11 to adjust the water concentration of the slurry, and an additive tank 1.
The additives supplied from No. 3 through line 14 and the returned matured high-concentration slurry that is matured in ripening machine 16 and returned through line 18 are mixed and adjusted together.

The adjusted high concentration slurry adjusted by mixing in the slurry adjustment tank 10 is sent to the ripening machine 16 from the line 15.
By further mixing, stirring and ripening in this ripening machine 16, a high quality matured highly concentrated slurry with low viscosity and uniformity is obtained. This matured high concentration slurry is transported via line 17, and one part is returned to line 18 as the matured high concentration slurry.
The other matured high concentration slurry is transported as a product high concentration slurry from a line 19 to a tank 20 for product high concentration slurry and stored therein.

FIG. 3 shows the flowchart of the second embodiment according to the first invention.
It is. The second embodiment shown in FIG. 3 stores dehydrated water discharged from a dehydrator 7 through a line 8 instead of the mill supply water tank 3 of the first embodiment shown in FIG. A circulating water tank 21 is provided, and a circulating water tank 21 and a line 4 are provided.
A water supply line 22 for circulating water is added. In addition.

23 is a line for replenishing fresh water when the water in the circulating water tank 21 becomes insufficient.

The dehydrated water obtained by the dehydrator 7 is sent from the line 8 and stored in the temporary circulating water tank 21.

Then, feed the required amount of mill supply water from line 22 to line 4.
The water is supplied to the wet mill 5 via.

In this way, in the second embodiment, the dehydrated water is transferred to the line 4.
This reduces the amount of water supplied from outside the system as much as possible by circulating the water through the system.

Also, in the embodiment illustrated in FIG.

By connecting the circulating water supply line 24 between the circulating water tank 21 and the line 12 as shown by the broken line,
The supply of water from outside the system may be further reduced, and the tank 11 for adjusting water may be omitted to further reduce costs.

As described above in detail based on the flow sheets of FIGS. 2 and 3 showing the embodiments of the first invention of the present invention, the following effects can be obtained by the first invention of the present invention. .

1) In a wet mill, pulverization is carried out at a low concentration (20 to 60% by weight of coal) where the pulverizing power is minimum, so it is possible to operate at the point where the pulverizing power is minimum.

2) Stir with a maturing machine such as a line mixer and return high-quality, low-viscosity, uniform slurry A portion of the matured high-concentration slurry is returned from the return circulation line for the matured high-concentration slurry to the slurry adjustment tank. Then, the uniformly returned matured high concentration slurry is constantly supplied and mixed with the adjusted high concentration slurry and stirred.

Therefore, the high concentration product slurry is always uniform, and when it is supplied as a product to combustion means such as a boiler, a steady combustion state can be obtained.

Next, the second invention of the present invention is provided in order to solve the problems of the first invention as described below and to obtain a high-concentration slurry of higher quality.

That is, in manufacturing according to the flow shown in FIGS. 2 and 3, the slurry adjustment tank 10 is
Since the dehydrated cake to be supplied is in the form of a plate or a large block, the adjusted water, additives, and return matured high concentration slurry are mixed together in a slurry adjustment tank 10, and then stirred in a ripening machine 16 such as a line mixer to re-slurry. When ripening a highly concentrated slurry with low viscosity, it was difficult to atomize it.

Therefore, in order to obtain uniform mixing, it is necessary to operate the slurry adjustment tank 10 and the ripening machine 16 for a long time, which increases the power cost and increases the productivity per unit time to obtain a high-quality, high-concentration slurry. was not sufficient.

Therefore, the second invention of the present invention solves the problems of the method for producing a low concentration wet high concentration slurry in the first invention,
The purpose of the present invention is to provide a high-quality, high-concentration slurry at a low cost and with higher productivity per unit time.

That is, the second invention of the present invention is as follows: 1. Coal is wet-pulverized in water using a wet mill to prepare a low-concentration slurry, the low-concentration slurry is then dehydrated to form a dehydrated cake, and the dehydrated cake is processed by a grinding device or torque After the slurry is crushed in a homogeneous grinding device, it is led to a slurry adjustment tank and supplied with adjustment water and additives, and then mixed with the uniformly returned matured high concentration slurry to form an adjusted high concentration water slurry. Making.

Furthermore, the above-mentioned adjusted high-concentration slurry is stirred in a ripening machine to mature into a uniform aged high-concentration slurry IJ- and supplied as a product, and a part of the above-mentioned aged high-concentration slurry is returned and circulated to the above-mentioned slurry adjustment tank. This is a method for producing a highly concentrated coal water slurry.

The following two preferred embodiments of the second invention are shown in FIG.
This will be explained in detail in the embodiment shown in FIG.

The embodiments illustrated in FIGS. 4 and 5 are flow sheets of the first embodiment and the second embodiment according to the second invention.

In the embodiment illustrated in FIGS. 4 and 5, reference numeral 1
Since numerals 1 to 24 are equivalent to numerals 1 to 24 in the embodiment shown in FIGS. 2 and 3, their explanation will be omitted.

25 is a grinding device, and 26 is a torque equalization type grinding device shown in FIG. It is crushed into lumps or micro lumps.

27 is a line for transporting the dehydrated cake in the form of small lumps or micro lumps (hereinafter referred to as the dehydrated cake in the form of small lumps).

Moreover, FIG. 6 is a perspective partial sectional view of the torque equalization type grinding device applied to each of the above embodiments. In Figure 6, 2
6a is the inlet of the dehydrated cake, 26bVi, the outlet of the small dehydrated cake +260Vi are mounted in parallel with an appropriate interval,
.

A wedge-shaped slit tapered toward the upper end is provided, and 26d is a rotating shaft disposed approximately at right angles to the longitudinal direction of the slit buddy group 26C.

26e A motor that rotates the Fi rotating shaft 26d.

Reference numeral 26f denotes a group of grinding partners that are provided out of phase when viewed in the circumferential direction of the rotating shaft 26d, and are fitted so as to mesh with each slit formed by the slit partners 26c.

In such an embodiment illustrated in FIG. 4, the coal in the coal storage tank 1 and the mill feed water in the feed water tank 3 are fed to the wet mill 5 via lines 2 and 4 and are ground to a low concentration. A low concentration slurry containing 20-60% by weight of coal is made. This low-concentration slurry is supplied to a dehydrator 7 through a line, and the resulting de-iced water is drained through a line 8, while the dehydrated cake is passed through a line 9 to a grinding device 25 or a torque-equalizing grinding device. 26.

In this grinding device 25 or the 1/1-lux type grinding device 26, the supplied plate-shaped or block-shaped dehydrated cake is crushed into small blocks or minute blocks. This small lump dehydrated cake is supplied to the slurry adjustment tank 10 via line 27.

In the slurry adjustment tank 10, a small lump-like dehydrated cake is produced.

Adjustment water tank 1 to adjust the water concentration of slurry
Conditioned water is supplied from 1 through line 12, and additive water is supplied from additive tank 13 through line 14.
The slurry is then aged in the ripening machine 16 and is mixed with the returned matured high concentration slurry that is returned via the line 8.

The adjusted high concentration slurry adjusted by mixing in the slurry adjustment tank 10 is sent to the ripening machine 16 through a line 15.

By further mixing, stirring and ripening in this ripening machine 16, a high quality matured highly concentrated slurry with low viscosity and uniformity is obtained. This matured high concentration slurry is transported via line 17, and one part is returned to line 18 as the matured high concentration slurry.
The other matured high concentration slurry is transported as a product high concentration slurry from a line 19 to a tank 20 for product high concentration slurry and stored therein.

FIG. 5 shows the flow chart of the second embodiment according to the second invention.
It is. The second embodiment shown in FIG. 5 has a circulation system for storing dewatered water discharged from a dehydrator 7 through a line 8 instead of the mill supply water tank 3 of the first embodiment shown in FIG. A water tank 21 is provided, and a circulating water tank 21 is provided.
and the circulating water supply line 22 connecting the line 4 and the water supply line 22.

As shown by the broken line in FIG. 3, a circulating water supply line 24 may be provided between the circulating water tank 21 and the line 12 to achieve the effects described in the embodiment shown in FIG.

As described above in detail based on the flowchart 1 of FIGS. 4 and 5 showing the embodiments of the second invention, the second invention of the present invention is based on the above-described embodiments obtained in the first invention. In addition to the above effects, the following effects can be obtained.

1) In order to grind and supply the dehydrated cake to the slurry adjustment tank in the form of small pieces, it is necessary to grind the dehydrated cake into small pieces and supply it to the slurry adjustment tank. Mixing and agitation can be performed smoothly and a high-quality, uniform product slurry with high concentration can be obtained.

2) Also, uniform mixing can be done smoothly.

The amount of product-concentrated slurry produced per unit time is significantly increased, thus improving productivity.

3) In the case shown in Fig. 6, the grinding device is of a torque-equalizing type, so the torque applied to the motor is equalized, preventing the motor from overheating, and the grinding work can be carried out smoothly with a small-capacity motor. . Since the grinding process goes very smoothly in this way, a large amount of high-concentration product slurry can be produced smoothly.

Next, the third invention of the two inventions is provided in order to solve the problems of the first invention as described below and to obtain a high-quality, high-concentration slurry.

That is, in the production according to the embodiment shown in FIGS. 2 and 3, since two coals are crushed in water at a low concentration, only a small number of ultrafine coal particles are generated. therefore,
Since the resulting high-concentration slurry only contains a small amount of ultrafine coal particles, the rheological properties of the high-concentration slurry become dilatant, resulting in poor storage stability.

On the other hand, since the finished high-concentration slurry contains many coarse particles, the high-concentration slurry prepared by the conventional low-concentration wet high-concentration slurry manufacturing method is heated by combustion means such as a boiler (not shown). When burned, there is a large amount of unburned carbon, resulting in a large amount of residue in the boiler.

Moreover, there was a problem that the combustion efficiency was not sufficient.

Based on these findings, the third invention of the present invention solves the problems of the above-mentioned method for producing a low-concentration wet high-concentration slurry,
The purpose of the present invention is to provide a high-quality, high-concentration product slurry that has good storage stability and even higher combustion efficiency. That is, the third aspect of the present invention is to prepare a low-concentration slurry by wet-pulverizing coal in water with a wet mill, and then converting the low-concentration slurry into a coal low-concentration water slurry (hereinafter referred to as coarse) in a classifier. (described as grain-containing low concentration slurry)
and coal low concentration water slurry from which coarse grains have been removed (hereinafter referred to as coarse grain cut low concentration slurry), and the coarse grain containing low concentration slurry is returned to the wet mill for circulation, while the coarse grain cut The concentrated slurry is dehydrated to produce a coarse cut dehydrated cake, and the coarse cut dehydrated cake is led to a slurry adjustment tank, supplied with adjusted water and additives, and returned to a uniformly aged highly concentrated slurry. The adjusted high concentration slurry is further stirred in a ripening machine to mature into a uniform aged high concentration slurry and supplied as a product. This is a method for producing a highly concentrated slurry, characterized in that the slurry is returned and circulated to the slurry adjustment tank.

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. 7 and 8.

The embodiment illustrated in FIGS. 7 and 8.

This is a flow chart 1 of the first embodiment and the second embodiment according to the third invention.

In the embodiment illustrated in FIGS. 7 and 8, reference numeral 1
1 to 24 in the embodiment illustrated in FIGS. 2 and 3 with the same reference numerals.
Since they are equivalent to those having the same reference numerals among the elements 24 to 24, their explanation will be omitted. 9a is a transportation line for the coarse grain cut dehydrated cake; 28 is a classification for separating the coarse grains in the low concentration slurry supplied from line 6 and classifying them into coarse grain-containing low concentration slurry and coarse grain cut low concentration slurry. 29 is a return circulation line for a low-concentration slurry containing coarse particles for wet milling the coarse particles classified by the classifier 28 again in the wet mill 5;
#'i This is a transport line for the coarse cut low concentration slurry classified by the classifier 28.

In such an embodiment illustrated in FIG. 7, the coal in the coal storage tank 1 and the mill feed water in the tank 3 are supplied via lines 2 and 4 to the wet mill 5, where they are pulverized at a low concentration and the coal Make a low concentration slurry of 20 to 60% by weight.

This low concentration slurry is supplied to a classifier 28 via line 6 and is classified into coarse particle-containing low concentration slurry and coarse particle cut low concentration slurry. Line 2 is the low concentration slurry containing coarse particles.
The coarse particles contained therein are further crushed into fine coal or ultrafine coal by the wet mill 5.

On the other hand, the coarse grain cut low concentration slurry obtained in the second classifier 28 is supplied to the dehydrator 7 through a line 30.

The dehydrator 7 dewaters the coarse cut low-concentration slurry, and the dehydrated water is drained from the line 8, while the coarse cutlets i and dehydrated cake are supplied to the slurry adjustment tank 10 via the line 9a.

In the slurry adjustment tank 10, a coarse cut dehydrated cake is produced.

Adjustment water tank 1 to adjust the water concentration of slurry
Conditioned water is supplied from the additive tank 13 through the line 12, additive water is supplied from the additive tank 13 through the line 14, and is aged in the ripening machine 16 and returned through the line 18. The high concentration slurry is mixed with the high concentration slurry IJ-.The adjusted high concentration slurry adjusted by mixing in the slurry adjustment tank 10 is sent from the line 15 to the ripening machine 16, where it is further mixed, stirred and aged. By doing this, a high-quality aged high-concentration slurry with low viscosity and uniformity is obtained.The line 1
7, and one part is returned to the slurry adjustment tank 10 as a circulating matured high-concentration slurry via line 18, and the other matured high-concentration slurry is sent as product high-concentration slurry from line 19 to a tank for product high-concentration slurry. 20 and stored.

FIG. 8 is a flow sheet of a second embodiment according to the third invention. The second embodiment shown in FIG. 8 has a dehydrator 7 instead of the mill supply water tank 3 of the first embodiment shown in FIG.
A circulating water tank 21 is provided to store dehydrated water discharged from the tank via line 8, and a circulating water supply line 22 connecting the circulating water tank 21 and line 4 is also provided, as well as the broken line in FIG. As shown, a circulating water supply line 24 may be provided between the circulating water tank 21 and the line 12 to achieve the effects described in the embodiment shown in FIG. 3.

As described above in detail based on flowchart-1 in FIGS. 7 and 8 showing the embodiments of the third invention of the present invention, the third invention of the present invention is based on the above-mentioned method obtained in the first invention. In addition to the effects, the following effects can be obtained.

1) Since the low concentration slurry containing coarse particles is re-pulverized using a wet mill, there are very few coarse particles in the high concentration slurry, and the fine coal particles increase, making the rheological properties of the high concentration slurry pseudoplastic and storage. Stability is improved.

2) Since the low-concentration slurry containing coarse particles is classified using a classifier and ground again using a wet mill, the maximum diameter of the coarse particles in the high-concentration slurry can be arbitrarily selected. Therefore, it becomes easy to obtain a highly concentrated slurry with a desired particle size distribution.

3) Since the slurry is classified using a classifier and the low concentration slurry containing coarse particles is ground again using a wet mill, the amount of coarse particles in the 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 extremely reduced, the residue inside the boiler is almost completely eliminated, and the combustion efficiency is improved.

Next, the fourth invention of the second invention is provided for the purpose of obtaining a high-concentration slurry of even better quality by taking advantage of the synergistic effect of the effects of the second invention and the third invention. The fourth aspect of the present invention is to wet-pulverize two coals in water using a wet mill to prepare a low-concentration slurry, and then use a classifier to separate the low-concentration slurry into a coarse-grain-containing low-concentration slurry and a coarse-grain cut low-concentration slurry. Classified into.

The coarse grain-containing low concentration slurry is returned and circulated to the wet mill, while the coarse cut low concentration slurry is dehydrated to form a coarse cut dehydrated cake. After grinding with a mold grinding device, the slurry is introduced into a slurry adjustment tank, supplied with conditioning water and additives, and then mixed with the uniformly returned matured high-concentration slurry to create an adjusted high-concentration slurry. Furthermore, the adjusted high concentration slurry is stirred in a maturing machine to adjust it to a uniform matured high concentration slurry and supplied as a product, and a part of the matured high concentration slurry is returned and circulated to the slurry adjustment tank. This is a method for producing a highly concentrated slurry.

Hereinafter, two preferred embodiments of the fourth aspect of the present invention will be described in detail with reference to the embodiments illustrated in FIGS. 9 and 10.

The embodiments illustrated in FIG. 9 and FIG. 1O are flow sheets of the first embodiment and the second embodiment according to the fourth invention.

Referring to the embodiments shown in FIGS. 9 and 10, the same reference numerals 1 to 30 refer to the same reference numerals 1 to 30 in the embodiments shown in FIGS. 2 to 8. Since it is equivalent to that of , the explanation will be omitted.

Nafu・9a is a transportation line for coarse cut dehydrated cake, 2
7a is a transportation line for small-sized coarse cut dehydrated cakes.

In such an embodiment as illustrated in FIG. 9, the coal in the coal storage tank 1 and the mill feed water in the feed water tank 3 are fed to the wet mill 5 via lines 2 and 4 and are ground to a low concentration. A low concentration slurry containing 20-60% by weight of coal is made. This low concentration slurry is supplied to a classifier 28 via line 6 and is classified into coarse particle-containing low concentration slurry and coarse particle cut low concentration slurry. The coarse grain-containing low concentration slurry is returned to the wet mill 5 via a line 29, and the contained coarse grains are further ground into pulverized coal or ultrafine coal in the wet mill 5. On the other hand, the coarse grain cut low concentration slurry obtained in the second classifier 28 is supplied to the dehydrator 7 through a line 30. The coarse cut low concentration slurry is dehydrated in the dehydrator 7, and the dehydrated water is drained from line 8, while the coarse cut dehydrated cake is drained from line 9.
a to a grinding device 25 or a torque-equalizing grinding device 26 shown in FIG. The grinding device 25 or the torque-equalizing grinding device 26 crushes the fed plate-shaped or lump-like coarse cut dehydrated cake into small lumps or fine lumps. This small lumpy coarse cut dehydrated cake is transferred to line 27a.
The slurry is supplied to the slurry adjustment tank 10 via. In the slurry adjustment tank 10, the dehydrated cake is cut into small chunks of coarse particles.

Adjustment water tank 1 to adjust the water concentration of slurry
], the additives supplied from the additive tank 13 through the line 14, and the return aged high concentration slurry aged in the ripening machine 16 and returned via the line 18. Mix and adjust. The adjusted high-concentration slurry adjusted by mixing in the slurry adjustment tank 10 is sent to the ripening machine 16 from the line 15, and further mixed and stirred in the ripening machine 16 for ripening, thereby producing a high-quality matured slurry with low viscosity and uniformity. Obtain a highly concentrated slurry. This matured high-concentration slurry is transported via line 17, and one part is returned to the slurry adjustment tank 10 via line 18 as a return matured high-concentration slurry, and the other matured high-concentration slurry is sent as a product high-concentration slurry from line 19 to the product. Transported on evening 20 for high concentration 7 rally and stored at 6 degrees.

FIG. 10 is a flow sheet of a second embodiment according to the fourth invention. The second embodiment shown in FIG. 10 has a circulation system for storing dewatered water discharged from a dehydrator 7 through a line 8 instead of the mill supply water tank 3 of the first embodiment shown in FIG. A water tank 21 is provided.

Furthermore, there is also a circulating water supply line 22 connecting the circulating water tank 21 and the line 4, and a circulating water supply line between the circulating water tank 21 and the line 12 as shown by the broken line in FIG. 24 may be provided to achieve the effects described in the embodiments shown in FIGS. 3 and 5.

As described above in detail based on the flow sheets of FIGS. 9 and 10 showing the embodiments according to the fourth invention of the present invention, the fourth invention of the present invention is based on the above-described embodiments obtained in the first to third inventions. In addition to the above effects, the following effects can be obtained.

1) Classify before dewatering, send the low-concentration slurry containing coarse particles back to the wet mill and crush it again, dehydrate only the low-concentration slurry from which coarse particles have been cut, and then process the coarse particles into plate-like or lump-like coarse particles after dewatering. In order to crush the grain-cut dehydrated cake into small pieces using a grinding device or a torque-equalizing grinding device and supply it to the slurry adjustment tank, -! ,Ta. In the slurry adjustment tank, the high concentration slurry that has been aged in the ripening machine is always returned and adjusted all at once, so the synergistic effect of these makes it possible to obtain a high concentration slurry of extremely high quality.

Next, the fifth invention of the present invention is a further improvement of the third invention. That is, in the third invention, 1 coal is 20 to 60% by weight.
The classification efficiency was not sufficient because the low-concentration slurry was directly classified. Therefore, an excessive amount of energy is required for classification, and the time required for classification is long, which may cause problems in production efficiency.

A fifth aspect of the present invention has been proposed to solve the above problems. That is, the fifth invention wet-pulverizes 7 coals in water using a wet mill to form a low-concentration coal slurry IJ.
- Then, the above-mentioned low-concentration slurry is diluted with dilution water, and then classified into coarse-grain-containing diluted low-concentration slurry and coarse-grain cut diluted low-concentration slurry using a classifier, and the above-mentioned coarse-grain-containing diluted low-concentration slurry is The slurry is returned to the wet mill and circulated, while the coarse cut diluted low concentration slurry is dehydrated to form a coarse cut dehydrated cake.

- The coarse-grain cut dehydrated cake described above is introduced into a slurry adjustment tank, supplied with adjustment water and additives, and then mixed with the returned matured high-concentration slurry, which is returned with uniformity, to form an adjusted high-concentration slurry 17-. The above-mentioned adjusted high-concentration slurry is further stirred in a maturing machine to prepare a uniform matured high-concentration slurry and supplied as a product, and a part of the above-mentioned returned matured high-concentration slurry is returned to the above-mentioned slurry adjustment tank for circulation. This is a method for producing a highly concentrated slurry, which is characterized by:

The following is a preferred embodiment of the fifth aspect of the present invention.
This will be explained in detail in the embodiment shown in FIG.

The embodiment illustrated in FIG. 11 and FIG. 12 is a flowchart of the first embodiment and the second embodiment according to the fifth invention.
It is.

In the embodiments shown in FIGS. 11 and 12, the elements 1 to 28 are equivalent to those with the same symbols, so their explanation will be omitted. 9a is a transportation line for the coarse grain cut dehydrated cake, 34a is a return circulation line for the coarse grain-containing diluted low concentration slurry, and 35a is a transportation line 31j for the coarse grain cut diluted low concentration slurry. a dilution tank for diluting the concentrated slurry to a concentration that is easy to classify with dilution water; 32 is a tank for dilution water; 33 is a dilution water supply line that supplies dilution water from the dilution water tank 32;
341 is a line for transporting a low concentration slurry (hereinafter referred to as diluted low concentration slurry) containing 15 to 40% by weight of coal and 60 to 85% by weight of water obtained by diluting in the dilution tank 31.

In such an embodiment as illustrated in FIG. 10, the coal feed of the coal storage tank 1 and the mill feed water of the feed water tank 3 are fed to the wet mill 5 via lines 2 and 4 and ground to a low concentration. The coal is processed to form a low concentration slurry of 20-60% by weight of coal. This low concentration slurry is led to a dilution tank 31 via line 6.

In this dilution tank 31, dilution water is supplied from a tank 32 through a line 33 to dilute it 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 9 coals. This diluted low concentration slurry is supplied to the classifier 28 through a line 34 and classified into a diluted low concentration slurry containing coarse particles and a diluted low concentration slurry containing 0 coarse particles. wet mill 5
The coarse particles contained therein are further ground into fine coal or ultrafine coal in a wet mill 5. On the other hand, the coarse grain cut diluted low concentration slurry obtained from the first classifier 28 is line 30a.
The water is supplied to the dehydrator 7 from In the dehydrator 7, the coarse cut diluted low concentration slurry is dehydrated, and the dehydrated water is drained through line 8, while the coarse cut dehydrated cake is supplied to the slurry adjustment tank 10 via line 9. In the slurry adjustment tank 10, a coarse cut dehydrated cake, adjustment water supplied from the adjustment water tank 11 via line 12 to adjust the water concentration of the slurry, and additives supplied from the additive tank 13 through line 14. The slurry is then mixed with the returned matured high concentration slurry that has been matured in the ripening machine 16 and is returned via the line 18. The adjusted high concentration slurry adjusted by mixing in the slurry adjustment tank 10 is passed through the line 15 to the ripening machine 16.
Send it to.

By further mixing and stirring in this ripening machine 16 and ripening, a high-quality matured high-concentration slurry with low viscosity and uniformity is obtained. This matured high-concentration slurry is transported by line 17, and one part is returned to the matured high-concentration slurry. Line 18 as slurry
The other matured high concentration slurry is transported as a product high concentration slurry from a line 19 to a tank 20 for product high concentration slurry and stored therein.

FIG. 12 is a flowchart of the second embodiment according to the fifth invention.
It is 1. The second embodiment illustrated in FIG.
In place of the mill supply water tank 3 of the first embodiment shown in the figure, a circulating water tank 21 is provided to store dehydrated water discharged from the dehydrator 7 via the line 8.

Further, a circulating water supply line 22 connecting the circulating water tank 21 and the mill supply water supply line 4, and a 12th
As shown by the broken line in the figure, the circulating water tank 21 and line 1
A water supply line 24 for circulating water is provided between the two.

The effects described in the embodiments illustrated in FIGS. 3, 5, and 8 may also be included.

Furthermore, in this second embodiment, a circulating water supply line 35 is provided between the circulating water tank 21 and the line 33, as shown by the dashed line in FIG. 12, to prevent water from being supplied from outside the system. Further savings may be made, and the dilution water tank 32 may be omitted to further reduce costs. Alternatively, any combination of circulating water supply lines 22°24.35 may be used.

As described above in detail based on flowchart 1 in FIGS. 11 and 12 showing the embodiments of the fifth invention of the present invention, the fifth invention of the present invention is based on the first and third inventions. In addition to the above-mentioned effects, the following effects can be obtained.

1) Before classification with the classifier, the low concentration slurry of 20-60% by weight of coal is diluted to a thin diluted low concentration slurry of 15-40% by weight of coal, improving the classification efficiency with the 2nd classifier and improving the product quality. Mass production of highly concentrated slurry is possible.

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

In other words, the sixth aspect of the present invention is to wet-pulverize two coals in water using a wet mill to prepare a low-concentration slurry, then dilute the low-concentration slurry with dilution water, and then use a classifier to prepare a diluted low-concentration slurry containing coarse particles. The coarse grain cut diluted low concentration slurry is classified into a concentrated slurry and a coarse grain cut diluted low concentration slurry, and the diluted low concentration slurry containing coarse grains is returned and circulated to the wet mill, while the coarse grain cut diluted low concentration slurry is dehydrated to form a coarse grain cut dehydrated cake. The above-mentioned coarse cut dehydrated cake is ground with a grinding device or a torque equalization type grinding device, then guided to a slurry adjustment tank, supplied with adjustment water and additives, and returned to a uniformly aged, high-concentration cake. The adjusted high-concentration slurry is mixed with the slurry to make an adjusted high-concentration slurry, and the adjusted high-concentration slurry is further stirred in a maturing machine to prepare a homogeneous matured high-concentration slurry, which is supplied as a product. This is a method for producing a highly concentrated slurry, characterized in that a part of the slurry is returned and circulated to the slurry adjustment tank.

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. 13 and 14.

The embodiments shown in FIGS. 13 and 14 are flow sheets of the first embodiment and the second embodiment according to the sixth invention.

Since they are equivalent to those shown in FIG. And 27a is a transportation line for small-sized coarse cut dehydrated cakes.

In such an embodiment illustrated in FIG. 13, the coal in the coal storage tank 1 and the mill feed water in the feed water tank 3 are fed to the wet mill 5 via lines 2 and 4 and are ground to a low concentration. A low concentration slurry containing 20-60% by weight of coal is made. This low-concentration slurry is led to a dilution tank 31 through a line 6, and diluted in the dilution tank 31 with dilution water supplied from a tank 32 through a line 33 to a concentration t that is easy to classify. That is, it is made into a diluted low concentration slurry of 15 to 40% by weight per coal.

This diluted low concentration slurry is passed through line 34 to classifier 2.
8 to classify into coarse grain-containing diluted low concentration slurry and coarse grain cut diluted low concentration slurry. The diluted low concentration slurry containing coarse particles is returned to the wet mill 5 via line 29a,
The contained coarse particles are further pulverized in a wet mill 5 into pulverized coal or ultrafine coal. On the other hand, the coarse grain cut diluted low concentration slurry obtained by the second classifier 28 is supplied to the dehydrator 7 from the line 30a. In the dehydrator 7, the coarse cut cut diluted low concentration slurry is dehydrated, and the dehydrated water is drained through line 8, while the coarse cut dehydrated cake is passed through line 9a to the grinding device 25.
Alternatively, it is supplied to the torque equalization type grinding device 26. The grinding device 25 or the torque-equalizing grinding device 26 grinds the fed plate-shaped or block-shaped coarse cut dehydrated cake into small lumps and fine lumps. This small-sized coarse-grained cut dehydrated cake is supplied to the slurry adjustment tank 10 via a line 272. In the slurry adjustment tank 10, small chunks of coarse grains are cut and dehydrated cakes are removed, adjustment water is supplied from the adjustment water tank 11 through line 2 to adjust the water concentration of the slurry, and adjustment water is supplied from the additive tank 13 through line 14. The additives and the returned aged high slurry aged in the ripening machine 16 and returned via the line 18 are mixed and adjusted together at -6°. The adjusted high-concentration slurry adjusted by mixing in the slurry adjustment tank 10 is sent to the ripening machine 16 from the line 15, and further mixed and stirred in the ripening machine 16 for ripening, thereby producing a high-quality matured slurry with low viscosity and uniformity. Obtain a highly concentrated slurry. This aged high-concentration slurry is transported through line 17, and one part is returned to the slurry adjustment tank 10 via line 18 as return matured high-concentration slurry IJ-, and the other matured high-concentration slurry is returned to line 19 as product high-concentration slurry. From there, the product is transported to a tank 20 for high concentration slurry and stored there.

FIG. 14 is a flow sheet of the second embodiment according to the sixth invention. The second embodiment shown in FIG. 14 replaces the mill supply water tank 3 of the first embodiment shown in FIG. A circulating water tank 21 for storage is provided, and furthermore, a circulating water supply line ring 22 connecting the circulating water tank 21 and the mill supply line 4, and a circulating water tank 21 and a line shown in FIG. ] 2 may be provided with a water supply line 24 for circulating water.

Furthermore, a circulating water supply line 35 is provided between the circulating water tank 25 and the line 32 as shown by the dashed line in FIG.
It is also possible to provide the same effects as the embodiments shown in FIGS. 3, 5, 8, 10, and 12.

As described above in detail based on the flowcharts of FIGS. 13 and 14 showing the embodiments according to the sixth invention of the present invention, the sixth invention of the present invention is based on the above-described embodiments obtained in the first to fifth inventions. In addition to the above effects, the following effects can be obtained.

Before classifying, dilute it to make it easier to classify.

The diluted low concentration slurry containing coarse particles is then returned to the wet mill and ground again, and only the diluted low concentration slurry from which the coarse particles have been cut is dehydrated. In order to grind the grain-cut dehydrated cake into small lumps using a block frame device or a torque equalization type grinding device and supply it to the slurry adjustment tank. In the slurry conditioning tank, the high-concentration slurry matured in the ripening machine is always returned and adjusted together, so the synergistic effect of these makes it possible to obtain a high-concentration slurry IJ- of extremely high quality.

[Brief explanation of the drawing]

DESCRIPTION OF SYMBOLS 1... Coal supply storage tank, 2... Coal supply line, 3... Mill supply water tank, 4... Mill supply water supply line, 5... Wet mill. 6...φ Low concentration slurry transport line, 7... Dehydrator, 8... Dehydrated water drainage line, 9... Dehydrated cake transport line, 9a... Coarse grain dehydrated cake transport line , 10... After slurry adjustment, 11... Tank for adjusted water, 12... Supply line for adjusted water, 13... Tank for additives, 14... Supply line for additives, 15.°
. Transportation line for adjusted high concentration slurry, 16... aging machine,
17... Transport line for aged high concentration slurry, 18...
・Return circulation line for return matured high concentration slurry, 19...
・Transportation line for high concentration product slurry, 20... Storage tank for high concentration product slurry, 21... Tank for circulating water. 22... Circulating water supply line, 23... Fresh water replenishment line, 24... Circulating water supply line. 25... Clumping device, 26... Torque equalization type grinding device, 27... Transport line for small lump dehydrated cake, 27a.
・Transportation line for small lumpy coarse cut dehydrated cake, 28・
...Classifier, 29...Return circulation line for low concentration slurry containing coarse particles. 29a...Return circulation line for diluted low concentration slurry containing coarse particles, 30...Transportation line for coarse cut low concentration slurry, 30aΦ...Coarse particles! - Transport line for diluted low concentration slurry, 31... dilution tank, 32... tank for dilution water. 33... Supply line for diluted water, 34... Transportation line for diluted low concentration slurry, 35... Circulation number. Figure 6 π6 1゜Before procedural amendment (method) August 1980) I+ Commissioner of the Japan Patent Office Display of the case 1982 Patent Application No. 91646 Title of invention Amending the method for producing highly concentrated coal water slurry Relationship with the famous case Patent applicant address No. 5-1 J-2 Marunouchi, Chiyoda-ku, Tokyo Name (620) Representative of Mitsubishi Heavy Industries, Ltd.・Insert the following sentence before the names of the main parts of the diagram.

Claims (1)

[Claims] 1) Coal is wet-pulverized in water using a wet mill to prepare a coal low-concentration water slurry, and then the above-mentioned coal low-concentration water slurry is dehydrated to form a dehydrated cake, and the dehydrated cake is transferred to a slurry adjustment tank. After supplying conditioned water and additives, the mixture is mixed with the uniformly returned matured coal high concentration water slurry to make a conditioned coal high concentration water slurry, and then the conditioned coal high concentration water slurry is further mixed with the returned matured coal high concentration water slurry. is stirred in a maturing machine to mature into a uniform aged coal high concentration water slurry and supplied as a product, and a part of the aged coal high concentration water slurry is returned and circulated to the slurry adjustment tank. Method for producing highly concentrated coal water slurry. 2) Wet-pulverize the coal in water using a wet mill to prepare a low-concentration coal water slurry, then dehydrate the above-mentioned coal low-concentration water slurry to form a dehydrated cake, and grind the dehydrated cake using a crushing device or a torque equalization type crusher. After being ground in a device, the slurry is led to a slurry adjustment tank where it is supplied with adjusted water and additives, and then mixed with the uniformly returned aged coal high concentration water slurry to create an adjusted coal high concentration water slurry. Further, the above-mentioned adjusted coal high-concentration water slurry is stirred in a maturing machine to mature into a uniform aged coal high-concentration water slurry and supplied as a product, and a part of the above-mentioned aged coal high-concentration water slurry is added to the slurry adjustment tank. A method for producing a highly concentrated coal water slurry, which comprises returning and circulating the slurry to a coal-rich water slurry. 3) Coal was wet-pulverized in water using a wet mill to prepare a low-concentration coal water slurry, and then the low-concentration coal water slurry was passed through a classifier to remove the coarse particles and the low-concentration coal water slurry. Coal is classified into low concentration water slurry. The low-concentration coal water slurry containing coarse particles is returned to the wet mill for circulation, while the low-concentration coal water slurry from which the coarse particles have been removed is dehydrated to form a coarse-cut dehydrated cake. Adjustment water and additives are supplied to the slurry adjustment tank, and then mixed with the uniformly returned matured coal high concentration water slurry to create an adjusted coal high concentration water slurry. Agitating the concentrated water slurry in a maturing machine to mature it into a uniform aged coal highly concentrated water slurry and supplying it as a product, and returning a part of the aged coal highly concentrated water slurry to the slurry adjustment tank for circulation. A method for producing a highly concentrated coal water slurry. 4) Coal was wet-pulverized in water using a wet mill to prepare a low-concentration coal water slurry, and then the low-concentration coal water slurry was passed through a classifier to remove the coarse particles and the low-concentration coal water slurry. Coal is classified into low concentration water slurry. The low-concentration coal water slurry containing coarse particles is returned to the wet mill for circulation, while the low-concentration coal water slurry from which the coarse particles have been removed is dehydrated to form a coarse-cut dehydrated cake. After being pulverized by a grinding device or a torque-equalizing grinding device, it is led to a slurry adjustment tank where adjustment water and additives are supplied, and it is mixed all together with the returned aged coal high concentration water slurry that is returned with uniformity. to prepare an adjusted coal high concentration water slurry, and further stir the adjusted coal high concentration water slurry in a maturing machine to mature it into a uniform aged coal high concentration water slurry and supply it as a product. A method for producing a highly concentrated coal water slurry, which comprises circulating a portion of the slurry back to the slurry adjustment tank. 5) Coal is wet-pulverized in water using a wet mill to prepare a low-concentration coal water slurry, and then the above-mentioned low-concentration coal water slurry is diluted with dilution water, and then used in a classifier to form a low-concentration coal layer containing coarse particles. The diluted coal low concentration water slurry from which coarse particles have been removed is classified into a water slurry and a diluted coal low concentration water slurry from which coarse particles have been removed, and the diluted coal low concentration water slurry containing the coarse particles is returned to the wet mill for circulation, while the diluted coal from which the coarse particles have been removed. The low-concentration water slurry is dehydrated to produce a coarse-grain cut dehydrated cake, and the coarse-grain cut dehydrated cake is led to a slurry conditioning tank, supplied with conditioning water and additives, and returned to a uniformly returned aged coal high-concentration water. The slurry is mixed with the slurry to make an adjusted coal high concentration water slurry, and the adjusted coal high concentration slurry is further stirred in an aging machine to mature into a uniform aged coal high concentration water slurry, which is then supplied as a product and the above-mentioned A method for producing a high-concentration coal water slurry, which comprises circulating a portion of the aged coal high-concentration water slurry back to the slurry adjustment tank. 6) Coal is wet-pulverized in water using a wet mill to prepare a low-concentration coal water slurry, and then the above-mentioned low-concentration coal water slurry is diluted with dilution water, and then used in a classifier to obtain diluted low-concentration coal water containing coarse particles. The slurry and the diluted coal low concentration water slurry from which the coarse particles have been removed are separated, and the diluted coal low concentration water slurry containing the coarse particles is returned to the wet mill for circulation, while the diluted coal low concentration water slurry from which the coarse particles have been removed is The concentrated water slurry is dehydrated to form a coarse cut dehydrated cake, and the coarse cut dehydrated cake is pulverized using a grinding device or a uniform type grinding device, and then introduced into a slurry conditioning tank where conditioned water and additives are added. The supplied and returned matured coal high-concentration water slurry is mixed together to create an adjusted coal high-concentration water slurry, and the adjusted coal high-concentration water slurry is further stirred in a maturing machine to achieve uniformity. A method for producing a high-concentration coal water slurry, which comprises aging a certain amount of aged coal into a high-concentration water slurry and supplying the slurry as a product, and circulating a portion of the aged coal high-concentration water slurry back to the slurry adjustment tank.