JPS6295150A - Mill for producing slurry - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a mill for producing slurry.

[Prior art 1] Conventionally, this type of mill for slurry production divides the mill into a plurality of grinding chambers by partition walls provided in the longitudinal direction of the mill, and each grinding chamber from the inlet to the outlet of the mill has a particle size distribution. The solid material and liquid supplied from the mill inlet are each filled with a grinding medium whose average particle size is gradually reduced, and the solid material and liquid supplied from the mill inlet are subjected to the grinding action by the rotation of the mill, and the particle size becomes fine and is discharged from the mill outlet with a certain concentration, forming a slurry. is manufactured.

FIG. 4 shows a conventional slurry manufacturing mill.

1 indicates a mill, 2 a body of the mill, and 3 a liner provided on the inner wall surface of the body. 4 is the inlet of the mill, and 5 is the outlet of the mill. Partition walls 10 and 6 are provided inside the mill to divide the mill into a grinding chamber 11 on the mill inlet side and a grinding chamber 12 on the mill outlet side.

These grinding chambers 11 and 12 are filled with grinding media having different particle size distributions, respectively, and rotate about an axis m.

When a solid material and a liquid are supplied from the inlet 4 of the mill at a predetermined supply rate, the solid material is subjected to a crushing action and becomes thin, and the solid material is passed through the partition wall 10 with a concentration corresponding to the predetermined supply rate. The slurry is produced by passing through a gap (not shown) provided at G and being discharged from the mill outlet 5. In addition, as another configuration of the partition wall, a scraping plate may be provided inside the partition FJJ wall to move the slurry in the grinding chamber to the next grinding chamber.

At this time, a dispersant made of a surfactant or the like is added together with the solid material and liquid to improve pulverization.

As mentioned above, the grinding chambers 11 and 12 are each filled with a grinding medium with a different particle size distribution, and in order to increase the grinding efficiency, the medium is filled in a large amount from the inlet to the outlet of the mill, depending on the particle size of the solid material. It is preferable that the grinding media are arranged in order from those with larger diameters to those with smaller diameters, and that small diameter grinding media are used for fine pulverization. However, in reality, due to the influence of the flow of solid materials and fluids in the mill, they may be arranged in the opposite direction, which reduces the grinding efficiency. However, as mentioned above, the partition walls 10 and 6 are provided to divide the grinding chamber, and the grinding chamber 11 on the entrance side of the mill is filled with grinding media having a particle size distribution with a large average particle size. The grinding chamber 12 on the outlet side of the mill is filled with
is filled with a grinding medium having a particle size distribution with a small average particle size to prevent large-diameter grinding media from moving toward the mill outlet side.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional slurry production mill, the movement of the grinding medium in the grinding chamber of the mill is not consistent with the movement of the grinding medium in a mixed system of solid materials and liquid. The viscosity of the slurry, which is a mixed system, changes depending on the progress and concentration, and under high viscosity conditions, the movement of the grinding media becomes irregular, which adversely affects grinding efficiency and grinding performance. In addition, a relatively small-diameter grinding medium is used for fine grinding, but as the mill rotates, the grinding medium rises along the liner of the mill, reaches a certain height, and then falls. Although there are differences depending on the rotation speed of the mill, the impact action and grinding action between the grinding media and the solid material are insufficient. In particular, when slurry is in a highly viscous state, grinding using a grinding medium with a small unit weight does not provide good grinding efficiency or grinding performance, and in some cases, coarse particles may not be subjected to sufficient grinding action and may be crushed inside the mill. This caused problems such as finely ground slurry containing coarse particles being discharged from the mill.

The present invention solves these conventional problems,
The purpose of the present invention is to provide an excellent slurry production mill that can obtain high grinding efficiency and grinding performance even under high viscosity conditions by significantly promoting the movement of grinding media in the grinding chamber of the mill. It is something to do.

[Means for Solving the Problems] In order to achieve the above object, the present invention divides a mill into a plurality of grinding chambers by a partition wall provided in the direction of force of the mill, and divides the mill into a plurality of grinding chambers from the inlet to the outlet of the mill. Each grinding chamber is filled with a grinding medium having a particle size distribution and a sequentially decreasing average particle size, and the distance between the partition walls of the grinding chamber is set at a predetermined ratio between the average particle size of each grinding medium and the mill effective diameter. It is formed so as to hold.

"Function" The present invention has the following effects due to the above configuration.

In other words, in a mill, the grinding media has an average particle size according to the particle size distribution according to the particle size as the grinding of the solid material progresses, and in each grinding chamber, the particle size changes from large to small, and the average particle size gradually decreases. Grinding is carried out under the same filling conditions, and the partition walls on both sides of each grinding chamber apply shear force to the grinding media, causing them to move along the liner as the mill rotates. In order to further increase the motion of the grinding media, it is possible to significantly improve the grinding efficiency and grinding performance even under high viscosity conditions by promoting the grinding action such as the impact action between the grinding medium and the solid material. It can be measured.

[Embodiment] FIGS. 1 and 2 show an embodiment of the present invention.

In FIGS. 1 and 2, 1 indicates a mill, 2 is a body of the mill, and 3 is a liner provided on the interior surface of the body.

4 is the inlet of the mill, and 5 is the outlet of the mill. Inside the mill, there are a plurality of partition walls P+, P in the longitudinal direction of the mill.
2, P3, and P4.6, respectively, and the inside of the mill is divided into a plurality of grinding chambers C+, C2, and C3.

It is divided into C4 and C5. The length of the crushing chamber, that is, the interval between the partition walls of the crushing chamber, is expressed by the distance between their center lines, n+, 12. (13,14゜゜5)
The distance between the grinding chambers gradually decreases from the inlet to the outlet of the mill.

Each grinding chamber is filled with grinding media,
Both have different particle size distribution and average particle size of the grinding media.
Grinding chambers C+, C2, C3, C4.

The particle size distribution and average particle size of the grinding media are gradually reduced from the inlet to the outlet of C5 and the mill.

That is, the grinding chamber C1 on the inlet side of the mill is filled with a grinding medium having a particle size distribution with a small average particle size, and the grinding chamber C5 on the outlet side of the mill is filled with a grinding medium with a particle size distribution with a small average particle size. Similarly, the crushing chambers C2 and C
3. C4 is filled with a grinding medium having a particle size distribution in which the average particle size becomes smaller in order to prevent large-diameter grinding media from moving toward the mill outlet side.

The mill 1 rotates around its axis m, and when solid materials, liquids, and additives are supplied from the mill inlet 4 at predetermined supply rates, the solid materials are subjected to a pulverizing action. Then, the crushing chambers C+, C2, C3,
As it passes through C4 and C5, it becomes thinner and is discharged from the mill outlet with a concentration corresponding to the predetermined supply rate.

FIG. 2 is a sectional view taken along the line II shown in FIG. 1, and the mill 1 is rotating in the direction of arrow A.

8 is a grinding medium, and as the mill 1 rotates, the grinding medium 8 is lifted upward along the liner 3 and rises.
After reaching a certain height, it falls due to gravity. The state of the falling material is intense, and the solid material is pulverized by separate impact and grinding action between the pulverizing medium and the solid material. 7 is a slit provided in each partition wall,
Since the width of the slurry 1~ is narrower than the diameter of the grinding medium 8,
Grinding media is prevented from migrating into the adjacent grinding chamber,
Only the slurry passes through the slit 7 in the partition wall and is discharged from the mill outlet 5. Note that D indicates the effective diameter of the mill 1.

FIGS. 3(a) and 3(b) show the relationship between the distance between the partition walls of each grinding chamber of the mill 1 and the shear force acting on the grinding medium by the partition walls.

Figure 3(a) shows the partition wall P on both sides of any grinding chamber.
, Pi+1 is appropriate, and FIG. 3(b) shows a case where a similar interval tliJ) is inappropriate.

In both cases, the horizontal axis corresponds to the shell plate 2 of the mill 1, and h indicates the height of the partition walls P· and Pi+1, respectively.

In Fig. 3(a), the shear force curve acting on the grinding media at the partition wall P is shown as S.
The shear force curve acting on the grinding media at i+1 is Si
It is shown as +1. Also, shear force curve S3. is a composite curve of the respective shear force curves S1°Si+1.

The value of the shear force reaches its maximum value at the position where the grinding medium is in contact with and close to the partition walls P, , P, .
, P, , decreases at positions away from 1. Similarly, in Figure 3(b), each shear force curve is S
, , Si+1, the composite curve is shown by Ssj.

Composite shear force curve S in FIGS. 3(a) and 3(b) and $5. Looking at the shear force S acting on the grinding media by
1+1, and the resultant shear force SS at a position away from the partition wall P・, P1+1, ! 1 has decreased significantly, and almost no effect has taken place.

The inventors have discovered that for slurry production, the distance between the partition walls of each grinding chamber is formed to maintain a predetermined ratio between the average particle size of the grinding media filled in each grinding chamber and the mill diameter. It has been found that high grinding efficiency and grinding performance can be obtained in the mill even under high viscosity conditions.

The above relationship can be concluded by the following equation.

Hair ≦cL / (aF■+b) Hair: Distance between partition walls Lm) d: Average particle size (#) of the grinding media in each grinding chamber, critical measure standard arithmetic mean diameter, D: Mill effective diameter (s+) a: constant, -1,092X 10' b: constant, 0.01241 The data from the experimental example based on the above-mentioned example is the data obtained by manufacturing slurry using a mill according to the prior art and a mill according to the present invention. A comparison table is shown below. Furthermore, COM was used as the type of slurry.

As can be seen from the data in the table above, it is possible to improve the grinding efficiency and grinding performance in slurry production, and the grinding efficiency is increased without reducing power consumption, and the maximum particle size of the product at the mill exit is reduced. The n-value of the Rosin-Ral 111er equation, which indicates the particle size distribution of slurry products, has increased, proving that this mill is capable of producing slurry of excellent quality.

The mill for producing slurry used in this invention can be applied not only to COM but also to the production of CWM and various other ore slurries, and its embodiment is not limited to that of the above-mentioned embodiments. Of course.

[Effects of the Invention] As is clear from the above embodiments, the present invention has a method in which pulverization is carried out using a pulverizing medium in each pulverizing chamber of the mill having an average particle size according to a particle size distribution according to the particle size as the pulverization of the solid material progresses. In addition, shear forces are applied to the grinding media by partition walls on both sides of each grinding chamber, causing movement of the grinding media, which further adds to the movement of the grinding media along the liner as the mill rotates. Therefore, by promoting the crushing action such as the impact action between the crushing media and the solid material to become more intense, it is possible to significantly improve the crushing efficiency and crushing performance even under high viscosity conditions.

Furthermore, it promotes uniform mixing of the dispersant and the mixed system and the dispersion effect due to surface adsorption, which improves the viscosity of the mixed system and contributes to improvements in grinding efficiency and grinding performance. The effects are enormous.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a mill for slurry production according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line I-I in FIG. 1, and FIG.
The figure is an explanatory view of the first solid part, and FIG. 4 is a sectional view of a conventional slurry manufacturing mill. 1... Mill 8... Grinding media C+, C
2, C3, C4, C5...Crushing chamber (L+, (12,1
3, 14, 15... = Partition plate spacing Application Person Kawasaki Heavy Industries, Ltd. Figure 1 Figure 4

Claims (1)

[Claims] The mill is divided into a plurality of grinding chambers by partition walls provided in the longitudinal direction of the mill, and each grinding chamber from the inlet to the outlet of the mill is filled with grinding media having a particle size distribution and a sequentially decreasing average particle size. A mill for producing slurry, characterized in that the interval between the partition walls of the grinding chamber is formed to maintain a predetermined ratio between the average particle size of each grinding medium and the effective diameter of the mill.