JPS62144758A - Mill for preparing 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 by wet grinding.

[Prior Art] Conventionally, this type of slurry production has been carried out using a body liner, a so-called classification liner, which aims to improve the classification of the grinding media introduced into the mill, without dividing the mill in the longitudinal direction by partition walls. Using a mill for slurry production equipped with a chisel, or dividing the mill into multiple grinding chambers using partition walls installed in the longitudinal direction of the mill, each grinding chamber from the inlet to the outlet of the mill has a particle size distribution and an average particle size distribution. Using a slurry manufacturing mill filled with grinding media so that the diameter decreases sequentially, 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 reaches a certain concentration at the mill outlet. slurry is produced. As a conventional classification liner, for example, there is a structure as shown in Japanese Patent Publication No. 57-32622.

FIG. 3 shows a conventional slurry manufacturing mill.

In FIG. 3, 1 indicates a mill, 2 is a body of the mill, and 3 is a classification 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. Reference numeral 6 indicates a partition wall on the exit side of the mill, and reference numeral 11 indicates a crushing chamber. Grinding chamber 11
is filled with a grinding medium having a particle size distribution, and the axis center m
It rotates around the center. The solid material and liquid supplied from the mill inlet 4 are pulverized by the rotation of the mill, resulting in finer particles, and are discharged from the mill outlet 5 with a certain concentration to produce a slurry.

FIG. 4 shows another conventional slurry manufacturing mill.

In FIG. 4, 1 indicates a mill, 2 is a body of the mill, and 3 is 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°, 10', and 6 are provided inside the mill to divide the mill into a grinding chamber 11 on the mill inlet side, an intermediate grinding chamber 12, and a grinding chamber 13 on the mill outlet side. These grinding chambers 11, 12 and 13
are respectively filled with grinding media having different particle size distributions, 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 pulverized and becomes thinner, and is delivered to the partition wall 10.11'6 with a concentration corresponding to the predetermined supply rate. The slurry is produced by passing through a gap (not shown) 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 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.

In any of the slurry manufacturing mills shown in Figures 3 and 4, ideally the entrance of the mill should be adjusted according to the pulverized particle size in the mill due to the effects of slurry viscosity and slurry flow in the slurry manufacturing process. It is desirable that the average particle size of the grinding media be arranged in order from large to small towards the exit, but in reality, the grinding media may be arranged in the opposite direction. Since this would reduce the grinding efficiency, the grinding media were arranged in an appropriate manner. For this reason, the mill for producing slurry shown in FIG. 3 uses a classified liner as the body liner. In addition, although the slurry production mill shown in Figure 4 has a partial arrangement, partition walls 10°, 10', and 6 are provided as described above to divide the grinding chamber, and the grinding chamber is separated from the grinding chamber at the entrance side of the mill. The chamber 11 is filled with a grinding medium having a particle size distribution in which the average particle size becomes larger, and the intermediate grinding chamber 12 and the grinding chamber 13 on the exit side of the mill are filled with grinding media having a particle size distribution in which the average particle size becomes smaller in order. This prevents large-diameter grinding media from moving toward the mill outlet.

[Problems to be solved by the invention] In recent years, the quality required for slurry in slurry production using a wet ball mill is 74 μm80 in particle size distribution.
%, and the maximum particle size is often limited. In pulverization in such a fine pulverization region, it has been demonstrated that the pulverization efficiency can be improved by using small-diameter balls as the pulverizing medium filled in the mill. In such a case, the particle size distribution width of the grinding medium itself becomes wider, and in a conventional slurry production mill, the average particle size distribution of the grinding medium increases from the inlet to the outlet of the mill, especially when the slurry is in a high viscosity state. It becomes difficult to obtain an ideal arrangement in which the particle size gradually changes from large to small, making it impossible to obtain good grinding efficiency and performance, and in some cases, coarse particles receive sufficient grinding action. There were problems such as the finely ground slurry containing coarse particles being discharged from the mill.

The present invention solves these conventional problems,
The object of the present invention is to provide an excellent mill for slurry production that can obtain high grinding efficiency and grinding performance even under high viscosity conditions.

[Means for Solving the Problems] In order to achieve the above object, the present invention divides the mill into a plurality of grinding chambers by partition walls provided in the longitudinal direction of the mill, and each grinding chamber runs from the inlet to the outlet of the mill. The chamber is equipped with a body liner that classifies the grinding media introduced into the mill.
Each of the grinding media is filled with a grinding medium having a particle size distribution and the average particle size decreasing sequentially.

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

That is, when a solid material and a liquid are supplied from the mill inlet at predetermined supply rates, the solid material is subjected to a crushing action and becomes thin. In a mill, each grinding chamber equipped with a classification liner changes from a large diameter to a small diameter, depending on the grinding media that has an average particle size according to the particle size distribution according to the particle size as the solid material is crushed. Grinding is carried out in a packed state in which the average particle size is gradually reduced, and the movement of the grinding media along the classification liner as the mill rotates creates a striking effect between the grinding media and the solid material. By promoting the pulverizing action, including pulverization, even under high viscosity conditions, finely pulverized slurry containing coarse particles is not discharged from the mill, and pulverization efficiency and performance can be significantly improved. .

[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 classification 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. Inside the mill, there are a plurality of partition walls 10 in the longitudinal direction of the mill.
10' and 6 are provided, respectively, and the interior of the mill is divided into a plurality of grinding chambers 11, 12, and 13. This example is divided into royal areas.

Each of the grinding chambers is filled with a grinding medium, and the average particle size is successively reduced from the inlet to the outlet of the grinding chambers 11, 12, 13 and the mill. That is, the grinding chamber 11 on the inlet side of the mill is filled with a grinding medium having a particle size distribution in which the average particle size is small, and the grinding chamber 13 on the outlet side of the mill is filled with a particle size distribution in which the average particle size is small. By filling the grinding medium with a grinding medium having a particle size distribution in which the average particle size becomes smaller in order, the partition wall prevents large-diameter grinding media from moving to the mill outlet, and the grinding chamber is filled with grinding media. Even within the crushing chamber divided by the attached classification liner 3, large-diameter crushing media are prevented from moving toward the mill outlet side.

The mill 1 is designed to rotate around its axis m, and when solid materials, liquids, and additives are supplied from the inlet 4 of the mill at predetermined supply rates, the solid materials are subjected to a pulverizing action. , becomes thinner as it sequentially passes through the grinding chambers 11, 12, and 13, 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. Reference numeral 8 denotes a grinding medium. 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 down due to the action of gravity. The state of the falling material is like a violent hot cloth, and impact action and grinding action occur between the grinding medium and the solid material, resulting in pulverization. 7
is a slit provided in each partition wall, and since the width of the slit is narrower than the diameter of the grinding medium 8, the grinding medium is prevented from moving to the adjacent grinding chamber, and only the slurry is passed through the slit in the partition wall. 7 and is discharged from the mill outlet 5. Note that D indicates the effective diameter of the mill 1.

Hereinafter, one embodiment of the present invention will be explained in comparison with the conventional technology.

FIG. 5 is an explanatory diagram showing a comparison between one embodiment of the present invention and the conventional technology.

FIG. 5(a) shows the progress of pulverization of a solid material in a conventional slurry production mill without partition walls. The vertical axis shows the crushed average particle size of the solid material, and the horizontal axis shows the distance from the mill inlet. 6 is a mill outlet partition wall. When a solid material and a liquid are each supplied from the mill inlet at a predetermined supply rate, the solid material is subjected to a pulverizing action, the average pulverized particle diameter dp of the solid material is reduced, and the solid material is discharged from the mill outlet via the mill outlet partition wall 6. .

FIG. 5(b) shows the selection of the diameter of the grinding media in the conventional slurry production mill shown in FIG. That is, the diameter of the grinding media filled in the mill is selected so as to correspond to the change in the grinding average particle size of the solid material in the mill, so that the grinding medium can be reliably ground to the grinding average particle size of the discharged slurry. The vertical axis is the grinding media diameter, the horizontal axis is the distance from the mill inlet, curve J2B,
l1BL and fLBU respectively indicate the diameter of the grinding medium corresponding to the grinding average particle size of the solid material at each distance from the inlet to the outlet, uB is the average diameter, λBL is the minimum diameter, uB[
] represents the maximum diameter. Also, 10.10'
There are two partition walls in the mill.
It is divided into three rooms marked 1°12.13.

Selection of the diameter of the grinding media is performed as follows. That is,
The range Bll of the diameter of the grinding media to be selected in the grinding chamber 11 is determined by the partition wall 10 and the curve flB, the maximum diameter of which is given by the point of the curve uBtl at the mill inlet, and the minimum diameter of which is the point of the grinding chamber outlet.
It is shown in the range represented by the intersection of L. Its range 8
The distribution of the diameters of the grinding media within 11 is determined by taking into account the average diameter IB. Similarly, a range B12 of the diameter of the grinding medium to be selected in the grinding chamber 12 and a range B13 of the diameter of the grinding medium to be selected in the grinding chamber 13 are determined. In addition, if the partition wall 10.10' is not provided, the length of the crushing chamber is i.
1, 12°13, and the range B of the diameter of the grinding media to be selected is determined.

FIG. 5(C) shows the selection of the diameter of the grinding media and the arrangement of the grinding media during operation in the conventional slurry production mill shown in FIG.

In FIG. 5(e), the average diameter AB, the minimum diameter I1. BL and maximum diameter nBU are the same as those shown in FIG. 5(b). According to the inventors' research, it has been found that in a mill for slurry production, the preferred range of the average diameter of the grinding media in order to obtain good grinding efficiency is between the upper limit value EBU and the lower limit value EBL. , these are each indicated by dotted lines. The explanations of the above-mentioned symbols are the same as those shown in FIG. 5(d) and FIG. 5(e), so the explanations in each case will be omitted. However, when a slurry production mill equipped with a conventional classification liner shown in Fig. 3 is operated, the average diameter of the grinding media exhibits an array as shown by curve C, and the mill inlet and mill outlet At each position in the vicinity, they are arranged outside the range of the upper limit value EBtl and the lower limit value EBL, which are the above-mentioned preferred ranges. That is, when a classification liner is used, only large-diameter grinding media are collected on the mill inlet side, and only small-diameter grinding media are classified and arranged on the mill outlet side. Therefore, good pulverization efficiency cannot be obtained in such areas, and only the area of the effective pulverization length expressed by EL contributes to good pulverization.

FIG. 5(d) shows the selection of the diameter of the grinding media and the arrangement of the grinding media during operation in the conventional slurry production mill shown in FIG.

In FIG. 5(d), when operating a slurry production mill without a classification liner, each grinding chamber 11, 1
The average diameter of the grinding media in 2.13 is the curve C1, f:
2. This results in the arrangement shown in C3. This is due to the high viscosity of the slurry and the fact that the slurry flows from the mill inlet to the mill outlet, forcing the large-diameter grinding media toward the mill outlet. That is, the center diameter of the grinding media is arranged so as to deviate from the range of the upper limit value EBU and lower limit value uBL, which should be a suitable range for grinding.

Therefore, the respective effective grinding lengths ELL, EL2. in each grinding chamber 11.12.13. The area of EL3 is extremely limited, and the effective crushing length EL of the mill as a whole
=EL1 +EL2 +EL3 was also not sufficiently obtained, and the fifth
The EL value is almost the same as that shown in Figure (C), and good pulverization efficiency cannot be obtained.

FIG. 5(e) shows the selection of the diameter of the grinding media of the mill for producing slurry according to the present invention and the arrangement of the grinding media during operation.

In Fig. 5(e), each grinding chamber 11, 12° 13 has a range B of the grinding media diameter as shown in Fig. 5(b).
11. B12. They are each filled with grinding media having a particle size distribution consisting of B13, with the average particle size decreasing in sequence. When the mill for slurry production according to the present invention is operated, the average diameter of the grinding media in each grinding chamber 11, 12, and 13 exhibits an array as shown by curves ell, C21, and C31, and Upper limit E that should be in a suitable range
llll and the lower limit value EBL. Therefore, the areas of the respective effective crushing lengths ELL, EL2, and EL3 in each crushing chamber are significantly expanded compared to the conventional one in FIG. 5(d), and the effective crushing length EL of the entire mill is also This can greatly increase the grinding efficiency and achieve good grinding efficiency. This is because the arrangement of the grinding media allows the slurry to have high viscosity, and the flow of the slurry from the mill inlet to the mill outlet prevents large-diameter grinding media from being pushed out to the exit side, allowing the classification effect of the classification liner to be achieved. In each grinding chamber, a large-diameter grinding medium is placed at the mill inlet, and a small-diameter grinding medium is placed at the mill outlet. This is due to the fact that original pulverization is possible with a pulverizing medium diameter having a corresponding constant dimensional ratio.

Next, a table is shown below in which data from experimental examples based on the above-described embodiments of the present invention are compared with data obtained by producing slurry using a mill according to the prior art and a mill according to the present invention. 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, increasing the grinding efficiency without reducing power consumption, and reducing the maximum particle size of the product at the mill exit. In particular, the n-value of the Rosin-RammJer 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 slurry production used in this invention can be applied not only to COM but also to CWM and other various types of ore slurry production, and its embodiment is similar to that of the above-mentioned embodiment. Of course, it is not limited.

[Effects of the Invention] As is clear from the above embodiments, each grinding chamber of the mill equipped with a classification liner has a fixed ratio corresponding to the reduction of the average particle size of the grinding as the grinding of the solid material progresses. Mill By significantly increasing the effective length of pulverization and promoting intense pulverization including impact action between the pulverizing media and the solid material, fine pulverization including coarse particles can be achieved even under high viscosity conditions. The grinding efficiency and grinding performance can be significantly improved without the slurry being discharged from the mill.

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-1 in FIG. 1, and FIG.
Figures 4 and 4 are cross-sectional views of a conventional slurry manufacturing mill.
FIGS. 5(a) to 5(e) are explanatory diagrams showing a comparison between an uninvented embodiment and the conventional technology. 1... Mil 3... Fuselage liner 4...
Mill inlet 5... Mill outlet 8... Grinding media if, 12.13... Grinding chamber

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 equipped with a body liner for classifying the grinding media introduced into the mill. A mill for producing slurry, characterized in that each mill is filled with grinding media having a particle size distribution and a progressively decreasing average particle size.