JPH10137609A - Method for operating horizontal ultrafine particle mill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a milling capacity and efficiency concerning a method for operating a horizontal ultrafine particle mill. SOLUTION: In a horizontal ultrafine particle mill for milling powder or slurry in which an outer cylinder 1 and an inner cylinder 2 are rotated by motors 5, 6 with the number of revolution and the direction of rotation selected optionally, milling balls 3 are put into the inside, and agitation is done by agitation blades 4, since two kinds of balls 3 with different diameters (for example, 10mmϕ+ 8mmϕ, or 10mmϕ+6mmϕ) are employed for milling, a milling time is reduced, power is saved, and milling efficiency improves as compared with conventional balls of a single diameter (for example, 10mmϕ).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for operating a horizontal ultrafine mill for dry and wet pulverization, which is applied to the production of ultrafine powder.

[0002]

2. Description of the Related Art FIG. 2 shows an internal sectional view of a case where a horizontal ultrafine mill is used in batch grinding. In the figure, the horizontal ultrafine mill is also called a UF (Ultra Fine) mill, 1 is a rotatable outer cylinder, 2 is an inner cylinder, and is rotatably arranged in the outer cylinder 1. 3 is a grinding ball, 4 is a stirring blade provided on the inner circumference of the outer cylinder 1 and the inner cylinder 2, 5 is a motor for rotating the outer cylinder 1, and 6 is a motor for rotating the inner cylinder 2.

[0003] As described above, the UF mill is mainly composed of the outer cylinder 1 and the inner cylinder 2 rotatable at an arbitrary number of revolutions and in the rotating direction, and the crushing balls 3 filled in the gap between them. . The gap between the grinding balls 3 is filled with dry powder in the case of dry grinding, and with dry powder and a solvent (water or oil) in the case of wet grinding, and rotated by the motor 5 of the outer cylinder 1 and rotated by the motor 6 of the inner cylinder 2. Further, the shearing force generated by the stirring blades 4 provided in the inner and outer cylinders is applied to the powder through the ball, and the fine pulverization is performed efficiently.

[0004]

In the above-mentioned conventional mill, it is widely known that, when fine grinding from several microns to submicron is performed, smaller balls have higher grinding efficiency. Until now, UF mills used balls having a single diameter of 6 to 10 mmφ. However, it is expected that the current grinding efficiency can be improved by using even smaller diameter balls.

However, when a small ball is used, it is necessary to improve the manufacturing accuracy because the ball bites into a constricted portion inside the mill, or a ball having a large particle size of the crushed raw material (for example, a 7 mm raw material is crushed with a 3 mm ball). Etc.), which makes it difficult to perform the pulverization, and requires prior pulverization to reduce the particle size of the raw material to be milled.

[0006]

The present invention provides the following means (1) and (2) in order to solve the above-mentioned problems.

(1) It has an inner cylinder and an outer cylinder which are rotatable and equipped with a stirring blade, and a crushed ball is filled in a gap between the inner and outer cylinders, and the inner cylinder and the outer cylinder are rotated at an arbitrary number of revolutions. In the method of operating a horizontal ultra-fine grain mill for rotating in the direction and crushing and continuously discharging the supplied powder or slurry, the grinding ball is characterized in that balls of different sizes are blended. how to drive.

(2) In the above (1), the inner cylinder and the outer cylinder are provided with a water-cooling jacket, and the powder or slurry is continuously discharged while cooling the pulverization heat while cooling. how to drive.

In the operation method (1) of the present invention, by blending balls having different diameters, the packing structure of the crushed balls becomes dense, and the transmission efficiency of the mill stirring energy is improved. Thus, it is possible to improve the pulverizing efficiency without newly providing a restriction on the constricted portion inside the mill or the particle diameter at the mill entrance. In (2), the above operation method is also applied to a horizontal ultra-fine grain mill in which the inner cylinder and the outer cylinder are water-cooled, and the pulverization efficiency can be similarly improved.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method of operating a horizontal ultrafine mill according to an embodiment of the present invention will be specifically described with reference to the drawings. The operation method of the present invention is based on the case where a conventional single-diameter crushed ball is used as a mixture of crushed balls having different diameters in a conventionally used horizontal ultrafine mill shown in FIG. This is an operation method in which the pulverization performance is improved as compared with.

FIG. 1 shows grinding balls in a horizontal ultrafine mill only with 10 mmφ (indicated by a symbol), 10 mmφ and 8 mmφ balls (indicated by a triangle), and 10 mmφ.
A combination of mmφ and 6mmφ balls (indicated by symbol square)
A comparison of the results of wet batch crushing of natural ore by changing the ball conditions, etc., (a) shows the relationship between the crushing time ratio and the average particle size, (b) shows the crushing time ratio and the net power unit ratio Respectively. The composition of the balls was 50%: 50% by weight.

FIG. 1 shows numerical values of the ratio of pulverization time and the net power consumption at the same average particle diameter of 2.5 μm. The values read from FIG. 1 are shown in Table 1 below as a comparison of the pulverization results. . From FIG. 1, it can be seen that by mixing balls having different diameters, a reduction ratio of the pulverization time to the same pulverization average particle diameter is possible.

[0013]

[Table 1]

As shown in Table 1 above, the grinding time of 10 mmφ + 8 mmφ, 10 mmφ + 6 mmφ is shortened as compared with the case of only 10 mmφ, so that the throughput (unit grinding capacity) of the mill having the same volume can be reduced. 25 to 3
5% improvement is possible.

[0015] Even if the ball diameter is reduced as a whole due to the blending of the balls, the remaining coarse particles in the pulverized powder (1 mm ↑ (wt%) in Table 1) can be reduced even if the balls are pulverized with a large diameter ball. Is equivalent to Therefore, it can be seen that the particle size distribution of the pulverized powder having the same average particle diameter is almost the same. It was also found that there was no problem with the restriction on the particle size of the pulverized raw material as is.

Furthermore, the electric power value required to pulverize the unit weight of the pulverized raw material to the target pulverized average particle diameter, that is, the power consumption unit (kWh / T), is smaller in the case of the compound ball pulverization. This is specified to be the result of having a denser filling structure by blending balls of different diameters and improving the transmission efficiency of the mill's stirring energy.

In the operation method described above, as shown in FIG. 1, the outer cylinder 1 and the inner cylinder 2 are rotated by motors 5 and 6 at an arbitrary number of revolutions and in a rotating direction to supply the supplied powder or slurry. In a horizontal ultra-fine grain mill that crushes and continuously discharges,
The milling balls are made of different sized balls, but the inner and outer cylinders of this horizontal ultra-fine mill are equipped with water-cooled jackets to efficiently cool the crushing heat of the powder or slurry while removing the crushed material. Naturally, the present invention can be applied as a method of operating a mill for continuous discharge, and has the same effect.

Further, in the above embodiment, 10 mm
Although the example using two types of balls, such as φ and 8 mmφ and 10 mmφ and 6 mmφ, has been described, using three types of balls slightly increases the pulverizing power but improves the pulverizing ability.

[0019]

As described above, the present invention has an inner cylinder and an outer cylinder which are rotatable and equipped with stirring blades,
A method of operating a horizontal ultrafine mill in which a grinding ball is filled between an inner cylinder and an outer cylinder to grind a powder or a slurry, wherein the grinding ball is operated as a compound having different diameters;
In addition, since this operation method can be applied to a mill that pulverizes the inner and outer cylinders while cooling the inner and outer cylinders with water, the packing structure of the pulverized balls is made denser to improve the energy transfer efficiency. It has become possible to greatly improve the pulverization processing capacity and the pulverization energy efficiency as compared with the operation method of the mill using the pulverizer.

[Brief description of the drawings]

FIG. 1 is a diagram showing ball mixing conditions and the results of natural ore pulverization applied to the operation of a horizontal ultra-fine grain mill according to an embodiment of the present invention. FIG. 1 (a) shows the relationship between the pulverization time ratio and the net power unit ratio. And (b) shows the relationship between the grinding time ratio and the average particle size, respectively.

FIG. 2 is a cross-sectional view of a horizontal ultrafine mill to which the operating method of the present invention is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outer cylinder 2 Inner cylinder 3 Grinding ball 4 Stirrer blade 5, 6 Motor

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Amano Olympic Rally No. 1-1 Akunouramachi, Nagasaki City Mitsubishi Heavy Industries, Ltd. Nagasaki Shipyard

Claims (2)

[Claims] 1. An inner cylinder and an outer cylinder which are rotatable and equipped with a stirring blade, and a gap between the inner cylinder and the outer cylinder is filled with crushed balls, and the inner cylinder and the outer cylinder are rotated at an arbitrary number of revolutions and rotation directions. In the method of operating a horizontal ultrafine mill, wherein the powder or slurry supplied is pulverized to continuously discharge the powder or slurry, wherein the pulverized balls are mixed with balls of different sizes. Method. 2. The method for operating a horizontal ultra-fine grain mill according to claim 1, wherein the inner cylinder and the outer cylinder are provided with a water-cooling jacket to continuously discharge the powder or slurry while cooling the pulverization heat. .