JPS60209265A - Crushing method by roller mill - 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 pulverizing method for pulverizing a material to be pulverized, such as cement clinker, using a roller mill.

(Prior art) In the past, tube mills were normally used to grind cement clinker, but when grinding with this tube mill, the ratio of fine powder generation is high and the quality of the cement as a product is excellent. On the other hand, there was a drawback that the electric power consumption required for the crushing work was extremely high.

By the way, in recent years, roller mills have been used to reduce the above-mentioned power consumption, but while roller mills have the advantage of requiring less power consumption for grinding, they have a narrower grinding area and longer grinding time than tube mills. Since the length is short, the ratio of fine powder generation is low and the particle size structure (particle size distribution range) is
A relatively narrow product is crushed. Therefore, especially when crushing cement clinker, the cement as a product has low initial strength and has poor workability.

In addition, recently, in order to compensate for the drawbacks of roller mills, 1
A roller mill is used for the next pulverization work, and a part of the product pulverized by the roller mill is subjected to a second pulverization work using a ball mill.
A pulverization method has been proposed in which the pulverized material obtained by only the primary pulverization is mixed with the pulverized material to produce a product. However, in this method, compared to pulverizing the entire amount using the tube mill, the power consumption is lower and energy saving can be achieved. In addition, although improvements such as improved product quality can be seen compared to pulverization using only a roller mill, a mixer is required to mix the primary pulverized material and the secondary pulverized material, making the manufacturing process more complicated. At the same time, it is difficult to uniformly mix the primary and secondary pulverized materials using a mixer, and especially if the particle size structure is uneven (segregation) when mixed, a product with an extremely low proportion of fine powder will be produced, and the quality of the product will deteriorate. There is a possibility that the product will be inferior to a product crushed by only a roller mill.

(Objective of the Invention) This invention has been made in view of the above points, and it is possible to achieve high pulverization efficiency and power consumption by mixing a certain amount of fine powder into the material to be pulverized in advance and pulverizing it during pulverization using a roller mill. The purpose of the present invention is to provide a pulverization method using a roller mill that takes advantage of the advantage of roller mills in reducing the number of units and compensates for the disadvantage of a small fine powder production ratio, thereby stabilizing the proportion of fine powder and improving the quality of the product.

(Structure of the Invention) The structure of the present invention, which aims to achieve the above-mentioned object, is characterized in that in the grinding operation using a roller mill, a certain amount of fine powder is mixed in advance into the object to be ground, and then the object is ground. The gist of this paper is a pulverization method using a roller mill.

Hereinafter, the pulverizing method of the present invention will be explained based on process diagrams showing each embodiment of pulverizing cement clinker.

In FIG. 1, a part of the fired cement crank force A is pulverized using a primary pulverizer 1 particularly suitable for producing fine powder, such as a tube mill, a vibrating ball mill, etc., and the pulverized clinker A is ' together with the remaining talin powder are put into a roller mill 2 and pulverized and mixed to produce cement C as a product.

Next, FIG. 2 shows a second embodiment in which limestone B is pulverized by the primary crusher 1 in place of the calcined talinka A, and then put into the roller mill 2 together with the talinka A to be crushed and mixed. B was used because it has lower hardness than Talinka A and is easier to pulverize, and when mixed into cement.
This is because it does not have a negative effect on the quality of the product, and is thought to have the same effect as the fine powder added to tarinka in improving the quality and workability of cement.

FIG. 3 shows the roller mill 2 and other crushing devices 111 (not shown).
A third embodiment is described in which fine powder A of tarinka discharged from the container and collected by a dust collector 3 such as an electric precipitator or a bag filter is charged into a roller mill 2 together with fired tarinka A and pulverized and mixed to produce cement C. show.

Furthermore, FIG. 4 shows that in the process shown in FIG. 1, the time between inputs of the talinka A to be crushed by the primary crusher 1 is adjusted so that the properties of the cement C, for example, the particle size composition, are adjusted to a predetermined set ratio. A part of the cement C after being crushed by the roller mill 2 is sampled, the particle size composition is measured by a measurement control device 4, and the speed of the feeder 5 for conveying to the primary crusher 1 is adjusted.

FIG. 5 shows that, in the process shown in FIG. 1, in order to obtain a predetermined bamboo-like cement C by adjusting the operating state of the primary crusher 1, a portion of the talinka A' after being crushed by the primary crusher 1 is removed. Analyzer 7 analyzes a part of cement as a product pulverized by roller mill 2, and analyzes the properties of a sample of cement C by using analyzer 6.
A comparison calculator 8 compares and calculates the analyzed numerical values, and a controller 9 adjusts the operating state of the primary crusher 1.

Note that, for example, when the primary crusher 1 is a ball mill, this adjustment of the operating state is performed by changing the rotational speed of the mill main body, the rotational speed of an attached separator, etc. In addition, it is also possible to control the period and properties of the primary crushing, which is a combination of FIGS. 4 and 5. Furthermore, the methods shown in FIGS. 4 and 5 can also be applied to FIG.

By the way, although the pulverizing method of the present invention is as described above, when manufacturing cement by pulverizing tarinka, there are some issues that affect workability due to the quality of the cement.
'TI' requires a minimum of 2% of the fine powder of 3μ or less, and it is desirable to be less than 10% from the point of view of power consumption. adjust. In addition, changes in product characteristics due to changes in the grinding characteristics of the roller mill 2 over time (for example, changes in grinding performance due to wear of the rollers and table liner, especially in this case, changes in the amount of fine powder produced are large) This can also be handled by adjusting the particle size structure and amount of the fine powder.

Furthermore, in each of the above embodiments, the case where the object to be crushed is cement clinker is illustrated, but the invention is not particularly limited to this, and it is applicable to the case where the object to be crushed is cement clinker. Applicable.

(Effects of the Invention) As explained above, in the grinding method of the present invention, when grinding with a roller mill, a certain amount of fine powder is mixed in advance into the object to be ground, and then the grinding is carried out, which improves the quality of the product. Since the necessary amount of fine powder is always ensured, the quality will not deteriorate even if the roller mill generates a small amount of fine powder.
In addition, the mixed fine powder and the material to be crushed are circulated many times in the roller mill while being subjected to the crushing action and mixed uniformly, so segregation (unbalanced particle size distribution) does not occur, the quality is stable, and the fine powder is evenly mixed. Since the amount of powder mixed in is small, the most suitable pulverizer for fine pulverization can be used for the pulverization work, and the majority of the pulverization work can be performed by a roller mill with low power consumption, reducing the total power consumption. It can save energy and reduce manufacturing costs. Furthermore, when a small amount of limestone powder is added, it acts as a grinding aid and has the effect of reducing the amount of power consumed by the roller mill itself.

[Brief explanation of the drawing]

Fig. 1 is a process diagram showing a first embodiment of this invention, Fig. 2 is a process diagram showing a second embodiment of this invention, Fig. 3 is a process diagram showing a third embodiment of this invention, and Fig. 4 is a process diagram showing a third embodiment of this invention. The figure is a process diagram showing the fourth embodiment of this invention, and FIG. 5 is a process diagram showing the fifth embodiment of this invention. It is a diagram. 1... Primary crusher, 2... Roller mill, 3... Dust collector, 4... Measurement control device, 5... Feeder, 6.
7...Analyzer, 8...Comparison calculator, 9...Controller. Recruiting 1 diagram 2 diagrams 3 diagrams

Claims (3)

[Claims] (1) A method of pulverization using a roller mill, characterized in that in the pulverization operation using a roller mill, a certain amount of fine powder is mixed in advance into the material to be pulverized, and then the material is pulverized. (2) When the material to be crushed is cement clinker, the particle size of the fine powder should be 3μ or less, and 2 to 10% of the total input amount.
% of the grinding method according to claim 21. (3) The pulverization method according to claim 1 or 2, wherein the particle size structure or amount of the fine powder to be mixed is adjusted based on the particle size structure of the product pulverized by the roller mill.