JPH0552357B2 - - Google Patents

Description

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

Coal high concentration water slurry (hereinafter referred to as high concentration slurry) is a mixture of 60 to 90% by weight of finely ground coal and 40% water.
A mixture of ~10% by weight and some additives,
It is a fluid fuel that can be burned as is in a boiler or the like without dehydration, and by converting coal, which is a solid fuel, into a fluid, its range of use can be dramatically expanded.

Conventionally, methods for producing high-concentration slurry can be broadly classified into three types: dry method, 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.

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 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. This is then dehydrated in a dehydrator to form a dehydrated cake, which is then mixed and stirred with a small amount of adjusted water and additives in a mixing agitator to form a highly concentrated slurry. It is.

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 Figure 1, a is a coal supply storage tank, b
is the coal supply line, c is the mill supply water tank, d is the mill supply water supply line, e is the wet mill, f is the transport line for the low concentration slurry obtained in the wet mill e, and g is the dehydrator. , the same dehydrator g dehydrates low concentration slurry. h is a line for draining the dehydrated water obtained by dehydration in dehydrator g, i is a transport line for the slurry obtained by dehydration in dehydrator g (hereinafter referred to as dehydrated cake), j is a mixing agitator,
k is a tank for adjusting water that supplies adjusted water to the mixing agitator j via the adjusting water supply line 1, and m is an additive tank that supplies the additive to the mixing agitator j via the additive supply line n. tank, o is a transportation line for the high concentration slurry product, and p is a storage tank for the high concentration slurry product or combustion means of a boiler (hereinafter referred to as product slurry tank).

In such a flow sheet, the storage tank a
Coal and mill feed water are supplied from tank c to wet mill e through lines b and d, and are pulverized to a low concentration to form 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 conditioning water and additives supplied from tanks k and m via lines 1 and n to form a highly concentrated slurry with low viscosity. The slurry is then supplied as a product from a high concentration slurry line o to a product slurry tank p.

In such a conventional low-concentration wet process high-concentration slurry manufacturing method, there is a problem of variation in quality of the high-concentration slurry that comes out as a product from the mixer j through the line o, that is, the quality uniformity. 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, in the first aspect of the present invention, coal is dry-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 passed through a slurry conditioning tank. The adjusted high concentration slurry is mixed with the uniformly returned matured high concentration slurry that is returned, and then the adjusted high concentration slurry is further stirred in a ripening machine. A method for producing a highly concentrated coal water slurry, which is characterized in that the slurry is aged to a uniformly aged highly concentrated slurry and supplied as a product, and a part of the aged highly concentrated slurry is returned and circulated to the slurry adjustment tank. .

Hereinafter, 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 sheet of the first embodiment according to the first invention.

In Figure 2, 1 is a coal supply storage tank, 2 is a coal supply line, 3 is a tank for mill supply water,
4 is a mill supply water supply line, 5 is a wet mill, 6
is a transport line for the low concentration slurry obtained by the wet mill 5; 7 is a dehydrator; the dehydrator 7 dehydrates the low concentration slurry to form a dehydrated cake. 8 is a drainage line for the dehydrated water obtained by the dehydrator 7, 9 is a transport line for the dehydrated cake obtained by dehydrating in the dehydrator 7, and 10 is a slurry adjustment tank or mixing agitator (hereinafter referred to as the slurry adjustment tank). , 11 is a conditioning water tank for storing water (hereinafter referred to as conditioning water) to be supplied to adjust the water concentration of the slurry in the slurry conditioning tank 10, 12 is a conditioning water supply line, and 13 is a conditioning water tank for adjusting the water concentration of the slurry in the slurry conditioning tank 10. A tank (hereinafter referred to as an additive tank) stores additives such as surfactants (hereinafter referred to as additives) to be supplied, 14 is an additive supply line, and 15 is a slurry height adjusted in the slurry adjustment tank 10. A transport line for concentrated slurry (hereinafter referred to as adjusted high concentration slurry), 16 is a ripening machine such as a line mixer (hereinafter abbreviated as ripening machine), and 17 is a high-quality, homogeneous slurry that has been stirred and matured in the ripening machine 16. A transport line for high concentration slurry (hereinafter referred to as aged high concentration slurry); 18 is a return circulation line for returning and circulating a portion of the matured high concentration slurry (hereinafter referred to as return aged high concentration slurry); 19 is for use as a product or in the next process; 20 is a transportation line for high-quality matured high-concentration slurry (hereinafter referred to as product high-concentration slurry) that is supplied to ).

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 illustrated in FIG.
The coal in the coal storage tank 1 and the mill feed water in the feed water tank 3 are passed through lines 2 and 4 to the wet mill 5.
20 to 60% by weight of coal that is supplied to the coal and pulverized at a low concentration
Make a low concentration slurry. 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 conditioning tank 10. In the slurry adjustment tank 10, a dehydrated cake is prepared, and a adjustment water tank 1 is used to adjust the water concentration of the slurry.
Conditioned water supplied from 1 through line 12, additives supplied from additive tank 13 through line 14, and aged in a ripening machine 16,
The slurry is mixed with the returned matured high-concentration slurry that is returned via 8. This slurry adjustment tank 1
The adjusted high-concentration slurry adjusted by mixing at 0 is sent to the ripening machine 16 from the line 15, and further mixed and stirred in this ripening machine 16 to mature it, thereby producing a high-quality matured high-concentration slurry with low viscosity and uniformity. Get 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. The slurry is transported and stored in a tank 20 for high concentration slurry.

FIG. 3 is a flow sheet of the second embodiment according to the first invention. The second embodiment illustrated in FIG.
In place of the mill supply water tank 3 of the first embodiment shown in FIG. 2, a circulating water tank 21 for storing dehydrated water discharged from the dehydrator 7 via a line 8 is provided. A water supply line 22 for circulating water connecting the tank 21 and the line 4 is added. Note that 23 is a line for replenishing fresh water when the water in the circulating water tank 21 becomes insufficient.

The dehydrated water obtained from dehydrator 7 is then transferred to line 8.
Temporarily stored in the circulating water tank 21. Then, a required amount of mill supply water is supplied from the line 22 to the wet mill 5 via the line 4.

In this way, in the second embodiment, by circulating the dehydrated water through the line 4, the supply of water from outside the system is reduced as much as possible.

In addition, in the embodiment shown in FIG. 3, by connecting the circulating water supply line 24 between the circulating water tank 21 and the line 12 as shown by the broken line, water from outside the system can be removed. further saving on supply,
Further, 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 embodiment according to 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, grinding is performed at a low concentration (20 to 60% by weight of coal) where the grinding power is minimal, so it is possible to operate at the point where the grinding power is minimal.

(2) Stir with a maturing machine such as a line mixer and return high-quality, uniform, and low-viscosity matured high-concentration slurry A portion of the matured high-concentration slurry is returned to the slurry adjustment tank from the return circulation line for the matured high-concentration slurry, so the slurry can be adjusted. In the tank, the uniformly returned aged high-concentration slurry is constantly supplied and mixed with the adjusted high-concentration slurry. Therefore, the product high concentration 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 better quality.

That is, in the production according to the flow shown in FIGS. 2 and 3, the dehydrated cake supplied to the slurry adjustment tank 10 via the line 6 is plate-shaped or large-sized, so the slurry adjustment tank 10 does not contain adjusted water or added water. When the high concentration slurry with low viscosity was matured by mixing the agent and the returned matured high concentration slurry together and stirring in a ripening machine 16 such as a line mixer to form a reslurry, it was difficult to atomize the slurry.
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 period of time, which increases the power cost and increases the cost per unit time to obtain a high-quality, high-concentration slurry. Productivity was not sufficient.

Therefore, the second invention of the present invention solves the problems of the low-concentration wet method high-concentration slurry production method in the first invention, and can produce high-quality product high-concentration slurry at low cost and at a low production rate per unit time. This is provided for the purpose of further increasing the quality of the product.

That is, the second invention of the present invention wet-pulverizes coal in water using a wet mill to prepare a low-concentration slurry, then dehydrates the low-concentration slurry to form a dehydrated cake, and applies the dehydrated cake to a crusher. Or, after crushing with a torque equalization type agglomeration device, the slurry is introduced into a slurry adjustment tank and supplied with adjustment water and additives, and then mixed with the uniformly returned matured high concentration slurry that is returned to form adjusted high concentration water. A slurry is made, and the adjusted high-concentration slurry is further stirred in a maturing machine to produce a uniformly aged high-concentration slurry, which is then supplied as a product.A portion of the above-mentioned matured high-concentration slurry is returned to the slurry adjustment tank for circulation. This is a method for producing a highly concentrated coal water slurry.

Hereinafter, preferred embodiments of the second aspect of the present invention will be described in detail with reference to the embodiments illustrated in FIGS. 4 and 5.

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 shown in FIGS. 4 and 5, the reference numerals 1 to 24 are equivalent to the reference numerals 1 to 24 in the embodiment shown in FIGS. 2 and 3, and therefore their explanation will be omitted. 25 is a crushing device, 26 is a torque equalizing type crushing device shown in FIG.
The plate-shaped or lump-shaped dehydrated cake supplied through the pulverizer is crushed into small lumps or minute lumps. 2
7 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 crushing device applied to each of the above embodiments. 6th
In the figure, 26a is the inlet of the dehydrated cake, 26b
26c is a group of wedge-shaped slit rods installed in parallel at appropriate intervals and tapers toward the upper end, and 26d is a group of slit rods arranged approximately at right angles to the longitudinal direction of the slit rod group 26c. A rotating shaft 26e is a motor that rotates the rotating shaft 26d,
26f is provided out of phase with respect to the rotational shaft 26d in the circumferential direction, and is provided with a slit rod 26c.
A group of rods for crushing agglomerates are fitted so that each rod engages with each slit made by.

In the embodiment shown 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 pulverized at a low concentration to form the coal. Make a low concentration slurry of 20-60% by weight. This low-concentration slurry is supplied to a dehydrator 7 through a line 6, and the dehydrated water produced by dehydration is drained through a line 8, while the dehydrated cake is passed through a line 9 to a crusher 25 or a torque equalizer type crusher. 26. The agglomeration device 25 or the torque-equalized agglomeration device 26 crushes the supplied plate-shaped or block-shaped dehydrated cake into small or minute agglomerates. Line 2
7 to the slurry adjustment tank 10. In the slurry adjustment tank 10, a small block dehydrated cake is prepared, and in order to adjust the water concentration of the slurry, a tank 11 for adjustment water is used.
conditioned water supplied from the additive tank 13 through line 14, additives supplied from the additive tank 13 through line 14, and return aged high-concentration slurry aged in the ripening machine 16 and returned via line 18. Mix and adjust. The adjusted high-concentration slurry adjusted by mixing in the slurry adjustment tank 10 is sent through a line 15 to a ripening machine 16.
By further mixing and stirring and aging, a high-quality aged high-concentration slurry with low viscosity and uniformity is obtained. This aged high concentration slurry is line 17
One part is returned to the slurry adjustment tank 10 as a return matured high concentration slurry via a line 18, and the other matured high concentration slurry is sent as a product high concentration slurry from a line 19 to a tank 20 for product high concentration slurry. Transport and store.

FIG. 5 is a flow sheet of a second embodiment according to the second invention. The second embodiment illustrated in FIG.
In place of the mill supply water tank 3 of the first embodiment shown in FIG. 4, there is provided a circulating water tank 21 for storing dehydrated water drained from the dehydrator 7 via the line 8, and The circulating water supply line 22 connecting the tank 21 and the line 4, and the third
As shown by the broken line in the figure, a circulating water supply line 24 may be provided between the circulating water tank 21 and the line 12 to obtain the effects described in the embodiment shown in FIG. 3.

As described above in detail based on the flow sheets of FIGS. 4 and 5 showing the embodiments of the second invention of the present invention, the second invention of the present invention achieves the above-mentioned effects obtained in the first invention. In addition, the following effects can be obtained.

(1) In order to supply the dehydrated cake to the slurry adjustment tank by crushing it into small pieces, it is uniformly mixed with the conditioning water, additives, and returned aged high-concentration slurry for slurry adjustment that is supplied to the slurry adjustment tank. Mixing and agitation goes smoothly and a high-quality, uniform, high-concentration product slurry can be obtained.

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

(3) In the case shown in Fig. 6, since the crushing device is of the torque equalization type, the torque applied to the motor is equalized and overheating of the motor can be prevented.
The small capacity motor allows smooth crushing work.
Since the agglomeration operation is performed very smoothly in this way, a large amount of high-concentration product slurry can be produced smoothly.

Next, the third 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-quality highly concentrated slurry.

That is, in the production according to the embodiment illustrated in FIGS. 2 and 3, only a small amount of ultrafine coal particles are produced because the coal is crushed in water at a low concentration. Therefore, since the resulting highly concentrated slurry contains only a small amount of ultrafine coal particles, the rheological properties of the highly concentrated slurry become dilatant, resulting in poor storage stability.

On the other hand, since the finished high-concentration slurry contains a large amount of coarse particles, the high-concentration slurry prepared by the conventional low-concentration wet method for producing high-concentration slurry is burned using a boiler or other means (not shown). When combusted in a boiler, there was a problem that there was a large amount of unresolved carbon and a large amount of residue was left in the boiler, and 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 manufacturing a low-concentration wet high-concentration slurry, and provides a high-quality product high-concentration slurry with good storage stability and even higher combustion efficiency. The purpose is to That is, in the third aspect of the present invention, coal is wet-pulverized in water using a wet mill to prepare a low-concentration slurry, and then the low-concentration slurry is passed through a classifier to form a coal low-concentration water slurry ( The coarse grain-containing low-concentration slurry is divided into a 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 passed through the wet mill. On the other hand, the coarse cut low concentration slurry is dehydrated to form a coarse cut dehydrated cake, the coarse cut dehydrated cake is led to a slurry adjustment tank, and adjusted water and additives are supplied thereto.The uniformity of the slurry is returned. The adjusted high concentration slurry is mixed together with the returned matured high concentration slurry, and the adjusted high concentration slurry is further stirred in an aging machine to mature into a uniform matured high concentration slurry, which is then supplied as a product. The method for producing a high-concentration slurry is characterized in that a part of the aged high-concentration slurry is circulated back 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 FIG. 7 and FIG.
1 is a flow sheet of a first embodiment and a second embodiment according to the invention.

In the embodiments shown in FIGS. 7 and 8, the same symbols among the symbols 1 to 24 are equivalent to the same symbols among the symbols 1 to 24 in the embodiments shown in FIGS. 2 and 3. Since this is a physical object, the explanation will be omitted. 9a is a transportation line for the coarse cut dehydrated cake, and 28 is a classification for separating the coarse particles in the low concentration slurry supplied from line 6 and classifying the coarse particles into a low concentration slurry containing coarse particles and a low concentration slurry containing coarse cut cuts. 29 is a return circulation line for the coarse grain-containing low concentration slurry for wet-pulverizing the coarse grains classified by the classifier 28 again in the wet mill 5; 30 is the coarse grain cut low concentration slurry classified by the classifier 28; transportation line.

In such an embodiment illustrated in FIG.
The coal in the coal storage tank 1 and the mill feed water in the tank 3 are supplied to the wet mill 5 through lines 2 and 4, and pulverized at a low concentration to form a low concentration slurry of 20 to 60% by weight of coal. This low concentration slurry is supplied to a classifier 28 through line 6 and is classified into a coarse particle-containing low concentration slurry and a 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 fine coal or ultrafine coal by the wet mill 5. On the other hand, the coarse cut low concentration slurry obtained in the classifier 28 is supplied to the dehydrator 7 through a line 30. In the dehydrator 7, the coarse cut low concentration slurry is dehydrated, and the dehydrated water is drained from the line 8, while the coarse cut dehydrated cake is supplied to the slurry adjustment tank 10 via the line 9a. In the slurry adjustment tank 10, coarse cut dehydrated cake, adjustment water supplied from the adjustment water tank 11 through a line 12 to adjust the water concentration of the slurry, and adjustment water supplied from the additive tank 13 through a line 14 are supplied. The mixed slurry is mixed with the return aged high concentration slurry aged in the ripening machine 16 and returned via the line 18. 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 to produce a high-quality slurry with low viscosity and uniformity. A matured highly concentrated slurry is obtained. This aged high concentration slurry is transported via line 17 and
The part is returned to line 1 as a circulating aged high concentration slurry.
The other matured high concentration slurry is returned to the slurry adjustment tank 10 via line 19 as product high concentration slurry to tank 20 for product high concentration slurry.
Transport and store.

FIG. 8 is a flow sheet of a second embodiment according to the third invention. The second embodiment illustrated in FIG.
In place of the mill supply water tank 3 of the first embodiment shown in FIG. A circulating water supply line 22 is connected to the tank 21 and the line 4, and a circulating water supply line 24 is provided between the circulating water tank 21 and the line 12 as shown by the broken line in FIG. The effects described in the embodiment illustrated in the figures may also be obtained.

As described above in detail based on the flow sheets of FIGS. 7 and 8 showing the embodiments of the third invention of the present invention, the third invention of the present invention has the above-mentioned effects obtained in the first invention. 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 rheological properties of the high concentration slurry become pseudoplastic due to the increase in fine coal particles. Improves storage stability.

(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 greatly reduced. Therefore, when the coal is combusted in a combustion means such as a boiler, the amount of unburned coal is extremely reduced, there is almost no residue in the boiler, and the combustion efficiency is 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 invention and the third invention to obtain a high-concentration slurry of even better quality.

That is, the fourth aspect of the present invention is to wet-pulverize coal 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 low-concentration slurry containing coarse grains and coarse grain cuts. The low concentration slurry containing coarse particles 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 being crushed using a lump crusher or a torque equalization type lump crusher, the slurry is led to a slurry adjustment tank where adjustment water and additives are supplied, and the slurry is mixed with the uniformly returned aged high concentration slurry for adjustment. A high-concentration slurry is made, and the adjusted high-concentration slurry is further stirred in a maturing machine to adjust it to a uniform matured high-concentration slurry, which is supplied as a product, and a part of the matured high-concentration slurry is transferred to the slurry adjustment tank. This is a method for producing a highly concentrated slurry characterized by return circulation.

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. 9 and 10.

The embodiments illustrated in FIGS. 9 and 10 are flow sheets of the first embodiment and the second embodiment according to the fourth invention.

In the embodiments illustrated in FIGS. 9 and 10, the same symbols among the symbols 1 to 30 are the same symbols among the symbols 1 to 30 in the embodiments illustrated in FIGS. 2 to 8. Since they are equivalent, their explanation will be omitted. Note that 9a is a transportation line for the coarse cut dehydrated cake, and 27a is a transportation line for the coarse cut dehydrated cake in the form of small blocks.

In such an embodiment illustrated in FIG.
The coal in the coal storage tank 1 and the mill feed water in the feed water tank 3 are passed through lines 2 and 4 to the wet mill 5.
20 to 60% by weight of coal that is supplied to the coal and pulverized at a low concentration
Make a low concentration slurry. This low concentration slurry is supplied to a classifier 28 through line 6 and is classified into a coarse particle-containing low concentration slurry and a coarse particle cut low concentration slurry. Line 29 is the low concentration slurry containing coarse particles.
The coarse particles contained therein are further pulverized into fine coal or ultrafine coal by the wet mill 5. On the other hand, the coarse cut low concentration slurry obtained in the classifier 28 is supplied to the dehydrator 7 through a line 30. In the dehydrator 7, the coarse cut 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 crusher 25 or to the torque uniform type lump shown in FIG. It is supplied to the crushing device 26. This agglomeration device 25 or torque-equalized agglomeration device 26 agglomerates the fed plate-shaped or lump-like coarse cut dehydrated cake into small or micro-agglomerates. This small-sized coarse cut dehydrated cake is passed through the line 27a to the slurry adjustment tank 1.
Supply to 0. In the slurry adjustment tank 10, small lumps of coarse cut dehydrated cake, adjustment water supplied from the adjustment water tank 11 through line 12 to adjust the water concentration of the slurry, and adjustment water supplied from the additive tank 13 through line 14. The additives are mixed together 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 sent from the line 15 to the ripening machine 16, where it is further mixed, stirred, and aged to produce a high-quality slurry with low viscosity and uniformity. A matured highly concentrated slurry is obtained. This matured 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.
9, the product is transported to a tank 20 for high concentration slurry and stored therein.

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. Water tank 21
Furthermore, a circulating water tank 21 and a line 4 are installed.
As shown by the broken line in FIG. 10, the circulating water supply line 22 connects the
It is also possible to provide a water supply line 24 for circulating water between the pump and the line 21 to obtain 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 of 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, and send the low-concentration slurry containing coarse particles to the wet mill and grind it again. Only the low-concentration slurry from which the coarse particles have been cut is dehydrated. In order to crush the coarse cut dehydrated cake into small chunks using a crushing device or a torque equalization type crushing device and supply it to the slurry adjustment tank,
In addition, in the slurry conditioning 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, coal 20
Since the slurry with a low concentration of ~60% by weight was directly classified, the classification efficiency was not sufficient. 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 coal in water using a wet mill to prepare a low-concentration coal slurry, then dilutes the low-concentration slurry with dilution water, and then uses a classifier to prepare a diluted low-concentration coal containing coarse particles. The coarse cut cut diluted low concentration slurry is classified into a concentrated slurry and a coarse cut cut diluted low concentration slurry, and the coarse cut diluted low concentration slurry is returned and circulated to the wet mill, while the coarse cut cut diluted low concentration slurry is dehydrated to form a coarse cut dehydrated cake. Then, the above-mentioned coarse cut dehydrated cake is introduced into a slurry conditioning tank, supplied with conditioning water and additives, and mixed with the returned matured highly concentrated slurry having uniformity to produce an adjusted highly concentrated slurry. Furthermore, the above-mentioned adjusted high-concentration slurry is stirred in a ripening machine to prepare a uniformly aged high-concentration slurry and supplied as a product, and a part of the above-mentioned returned matured high-concentration slurry is returned and circulated to the above-mentioned slurry adjustment tank. This is a method for producing a highly concentrated slurry characterized by the following.

Hereinafter, a preferred embodiment of the fifth aspect of the present invention will be described in detail with reference to the embodiment illustrated in FIGS. 11 and 12.

The embodiment illustrated in FIGS. 11 and 12 is
It is a flow sheet of the 1st Example and 2nd Example based on 5th invention.

In the embodiments shown in FIGS. 11 and 12, the same numbers among the numbers 1 to 28 are
Reference numeral 1 in the embodiment illustrated in FIGS.
Since they are equivalent to those having the same reference numerals among those in . 9a is a transport line for the coarse cut dehydrated cake, 34a is a return circulation line for the coarse grain-containing diluted low concentration slurry, and 35a is a transport line for the coarse cut diluted low concentration slurry 31 which has been supplied via line 6. a dilution tank that dilutes the low concentration 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;
34 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 illustrated in FIG. 10, the coal and feed water tank 3 of the coal storage tank 1
The mill feed water is supplied to the wet mill 5 through lines 2 and 4 and is ground at a low concentration to form a low concentration slurry containing 20 to 60% by weight of coal. This low concentration slurry is led to the dilution tank 31 via line 6,
This dilution tank 31 connects the tank 32 to the line 3.
Dilute with dilution water supplied through step 3 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 low concentration slurry is supplied to the classifier 28 through a line 34 and is classified into a coarse grain-containing diluted low concentration slurry and a coarse grain cut diluted low concentration slurry. The diluted low concentration slurry containing coarse particles is returned to the wet mill 5 via the line 29a, and the contained coarse particles are further ground into fine coal or ultrafine coal by the wet mill 5. On the other hand, classifier 2
The coarse cut diluted low concentration slurry obtained in step 8 is supplied to the dehydrator 7 from line 30a. Dehydrator 7
Then, the coarse cut diluted low-concentration slurry is dehydrated, and the dehydrated water is drained from 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, coarse cut dehydrated cake, adjustment water supplied from the adjustment water tank 11 through 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 sent from the line 15 to the ripening machine 16, where it is further mixed, stirred, and aged to produce a high-quality slurry with low viscosity and uniformity. A matured highly concentrated slurry is obtained. 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. The slurry is transported and stored in a tank 20 for high concentration slurry.

FIG. 12 is a flow sheet of the second embodiment according to the fifth invention. The second embodiment shown in FIG. 12 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 there is also a circulating water supply line 22 connecting the circulating water tank 21 and the mill supply water supply line 4, and a circulating water tank 21 as shown by the broken line in FIG. A water supply line 24 for circulating water may be provided between the pump and the line 12 to obtain the effects described in the embodiments shown in FIGS. 3, 5, and 8.

Furthermore, in this second embodiment, as shown by the dashed line in FIG.
A circulating water supply line 35 may be provided between the system and the water tank 3 to further reduce the supply of water from outside the system, and the dilution water tank 32 may be omitted to further reduce costs. Alternatively, the circulating water supply line 22,
Any combination of 24 and 35 may be used.

As described above in detail based on the flow sheets of FIGS. 11 and 12 showing the embodiments of the fifth invention of the present invention, the fifth invention of the present invention is obtained by the first invention and the third invention. In addition to the above effects, the following effects can be obtained.

(1) Before being classified with a classifier, 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, so 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 re-improvement of the first invention to the fifth invention.

That is, the sixth aspect of the present invention is to wet-pulverize coal 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 remove coarse particles. The diluted low-concentration slurry containing coarse grains is classified into the diluted low-concentration slurry and the 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 and processed into coarse cuts. The coarse cut dehydrated cake is crushed using a crusher or a torque equalization type crusher, and then introduced into a slurry adjustment tank, supplied with adjustment water and additives, and returned for uniform return aging. A high-concentration slurry is mixed with the high-concentration slurry to make an adjusted high-concentration slurry, and the adjusted high-concentration slurry is further stirred in a ripening machine to produce a uniformly matured high-concentration slurry, which is supplied as a product, and the above-mentioned matured high-concentration slurry is This method of producing a highly concentrated slurry is characterized in that a part of the concentrated 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.

In the embodiment shown in FIGS. 13 and 14, the same reference numerals 1 to 35 and the reference numerals 9a, 29a, and 30a correspond to the reference numerals 1 to 35 in the embodiment shown in FIGS. 2 to 12. Since these are equivalent to those having the same reference numerals and the reference numerals 9a, 29a, and 30a, their explanation will be omitted. and 27a
is a transportation line for small-sized coarse cut dehydrated cakes.

In such an embodiment as illustrated in FIG.
The mill feed water is supplied to the wet mill 5 through lines 2 and 4 and is ground at a low concentration to form a low concentration slurry containing 20 to 60% by weight of coal. This low concentration slurry is led to the dilution tank 31 via line 6,
This dilution tank 31 connects the tank 32 to the line 3.
Dilute with dilution water supplied through step 3 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 low concentration slurry is supplied to the classifier 28 through a line 34 and is classified into a coarse grain-containing diluted low concentration slurry and a coarse grain cut diluted low concentration slurry. The diluted low concentration slurry containing coarse particles is returned to the wet mill 5 via the line 29a, and the contained coarse particles are further ground into fine coal or ultrafine coal by the wet mill 5. On the other hand, classifier 2
The coarse cut diluted low concentration slurry obtained in step 8 is supplied to the dehydrator 7 from line 30a. Dehydrator 7
Then, 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 a crusher 25 or a torque-equalized crusher 26 via line 9a. This agglomeration device 25 or torque-equalized agglomeration device 26 agglomerates the fed plate-shaped or lump-like coarse cut dehydrated cake into small or micro-agglomerates. This small-sized coarse cut dehydrated cake is supplied to the slurry adjustment tank 10 via the line 27a. Slurry adjustment tank 1
0, small lumpy coarse cut dehydrated cake, conditioning water supplied from the conditioning water tank 11 via line 12 to adjust the water concentration of the slurry, additives fed from the additive tank 13 via line 14, and The slurry is mixed and adjusted together with the returned matured high-grade 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 sent from the line 15 to the ripening machine 16, where it is further mixed, stirred, and aged to produce a high-quality slurry with low viscosity and uniformity. A matured highly concentrated slurry is obtained. 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. Tank 2 for high concentration slurry
0 and stored.

FIG. 14 is a flow sheet of the second embodiment according to the sixth invention. The second embodiment shown in FIG. 14 has a circulation system for storing 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. water tank 2
1, and further a circulating water supply line 22 connecting the circulating water tank 21 and the mill supply line 4.
Alternatively, a circulating water supply line 24 may be provided between the circulating water tank 21 and the line 12 as shown by the broken line in FIG. 14, or furthermore, as shown by the dashed line in FIG. A circulating water supply line 35 is provided between the circulating water tank 25 and the line 32 to provide the same effect as the embodiments shown in FIGS. 3, 5, 8, 10, and 12. You can also look for effects.

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

(1) Before classification, dilute to make it easier to classify, and also cut coarse grains by classification. The diluted low concentration slurry containing coarse grains is returned to the wet mill and crushed again. In order to dehydrate only the low concentration slurry, and further crush the plate-shaped or lump-like coarse cut dehydrated cake after dehydration into small pieces using a crusher or torque equalization type crusher 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 of extremely high quality.

[Brief explanation of the drawing]

Figure 1 is a flow sheet related to the conventional low concentration wet high concentration slurry manufacturing method, and Figures 2 to 1
FIG. 4 is related to the present invention, FIG. 2 is a flow sheet of the first embodiment according to the first invention of the present invention, and FIG.
The figure is a flow sheet of the second embodiment, FIG. 4 is a flow sheet of the first embodiment according to the second invention of the present invention, FIG. 5 is a flow sheet of the second embodiment, and FIG. 6 is applied to related embodiments. FIG. 7 is a flow sheet of the first embodiment according to the third aspect of the present invention, FIG. 8 is a flow sheet of the second embodiment, and FIG. FIG. 10 is a flow sheet of the first embodiment according to the fourth invention of the present invention, FIG. 11 is a flow sheet of the first embodiment according to the fifth invention of the present invention, and FIG. FIG. 13 is a flow sheet of the second embodiment, FIG. 13 is a flow sheet of the first embodiment according to the sixth aspect of the present invention, and FIG. 14 is a flow sheet of the second embodiment. 1...Coal supply storage tank, 2...Coal supply line, 3...Mill supply water tank, 4...Mill supply water supply line, 5...Wet mill, 6...Transportation of low concentration slurry Line, 7... Dehydrator, 8...
Drainage line for dehydrated water, 9... Transport line for dehydrated cake, 9a... Transport line for coarse cut dehydrated cake, 10... After slurry adjustment, 11... Tank for adjusted water, 12... Supply line for adjusted water , 13...
Additive tank, 14...additive supply line,
15... Transportation line for adjusted high concentration slurry, 16
...Raturing machine, 17...Transportation line for aged high concentration slurry, 18...Return circulation line for return aged high concentration slurry, 19...Transportation line for product high concentration slurry, 20...Storage tank for product high concentration slurry , 21... Tank for circulating water, 22... Circulating water supply line, 23... Clean water replenishment line, 24...
...Circulating water supply line, 25...Clumping device, 26
...Torque uniform type agglomeration device, 27...Transportation line for small lumpy dehydrated cake, 27a...Transportation line for small lumpy coarse cut dehydrated cake, 28...Classifier, 2
9... Return circulation line for low concentration slurry containing coarse particles, 29a... Return circulation line for diluted low concentration slurry containing coarse particles, 30... Transport line for coarse cut low concentration slurry, 30a... Coarse cut dilution low Concentrated slurry transport line, 31... dilution tank,
32... Tank for dilution water, 33... Supply line for dilution water, 34... Transportation line for diluted low concentration slurry, 35... Water supply line for circulating water.

Claims (1)

[Claims] 1. Coal is wet-pulverized in water using a wet mill to prepare a coal low-concentration water slurry, then the above-mentioned coal low-concentration water slurry is dehydrated to form a dehydrated cake, and the dehydrated cake is led to a slurry adjustment tank and mixed with adjusted water. Additives are supplied and mixed together with the uniformly returned matured coal high concentration water slurry to make an adjusted coal high concentration water slurry, and the adjusted coal high concentration water slurry is further stirred in a maturing machine. A highly concentrated coal water slurry which is characterized in that the aged coal highly concentrated water slurry is aged into a homogeneous aged coal highly concentrated water slurry and supplied as a product, and a part of the aged coal highly concentrated water slurry is returned and circulated to the slurry adjustment tank. Production method.