JPH0639342B2 - Manufacturing method of granulated slag ultra fine powder - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing ultrafine powder useful for glass cement, water blocking agents, etc., by using granulated blast furnace slag as a raw material.

[Conventional technology]

Conventionally, there have been the following two methods for producing ultrafine powder. The granulated blast furnace slag is directly crushed with an ultrafine crushing mill,
There are a method of obtaining ultrafine powder and a method of further pulverizing the granulated fine powder for cement admixture obtained by pulverizing the granulated slag to obtain ultrafine powder.

[Problems to be solved by the invention]

However, the above method pulverizes both fine powder having a relatively large particle size and fine powder having a relatively small particle size, resulting in low pulverization efficiency, high power consumption, and high cost. As in the other method, a material having a coarse particle size is also used as a raw material, so that it consumes a large amount of electric power and has a large equipment capacity.

Therefore, a main object of the present invention is to provide an ultrafine powder manufacturing method which reduces the load on a pulverizer and reduces the cost.

[Means for solving problems]

Means for solving the above problems and achieving the object of the present invention, when producing ultrafine powder from granulated blast furnace slag, after the primary pulverization of this granulated slag to obtain fine powder, a part of the fine powder As a cement admixture product, the remaining fine powder is classified and sieved by a primary classifier based on 5 to 8 μm, the coarse fine powder is returned to the primary pulverizer, and the fine fine powder is converted into ultrafine powder by the secondary classifier. Classifying and sieving into coarse and fine powder, the ultrafine powder is commercialized as it is, the coarse and fine powder is secondarily pulverized in a pulverizing mill, and then returned to the secondary sizing in its entirety, and the primary and secondary sizing is a dry type air flow. Using
In addition, the primary pulverization and the secondary pulverization are also performed dry.

[Action]

In the present invention, after the primary crushing of the granulated blast furnace slag, it is sieved by the primary classifier, and the undersize product is further separated by the secondary classifier into relatively coarse fine powder and ultrafine powder to be the product as it is,
Since only this coarse fine powder is subjected to secondary pulverization with a pulverizing mill, the amount of secondary pulverization is small, and therefore the pulverization efficiency is extremely improved, and it is possible to reduce power consumption and equipment capacity.

[Specific configuration of the invention]

 Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a specific example of the method of the present invention, which is roughly composed of a former stage which is a fine powder manufacturing process and a latter stage which is an ultrafine powder manufacturing process. In the figure, first, the water granulated slag as a raw material is put into a hopper 1, and is put into a vertical roller mill 3 having a plurality of helical or conical rolls via a quantitative feeder 2, where the water granulated slag is primarily pulverized, While being carried on the hot air flow from the hot air generating furnace 4 and fed into the collector 5 and exhausted by the fan 6, fine powder is collected. Next, this fine powder is introduced into the silo 8 by the conveyor 7 and once stored, most of it is discharged as a product such as a cement admixture (a product of cement admixtures) by a lorry car 9. Part of the fine powder is discharged from the cutout valve 10 and charged into the hopper 12 via the conveyor 11. Next, a fixed quantity is sent to the conveyor 14 by the fixed quantity feeder 13 and is supplied to a primary classifier 15 such as a dry airflow classifier that obtains an airflow by a fan, for primary classification. In this classification, it is preferable to perform classification based on 5 to 8 μm. Such classification standards reduce the burden of secondary pulverization and improve pulverization efficiency.

The coarse fine powder discharged from the bottom of the primary classifier 15 is returned to the vertical roller mill 3 and the silo 8 for re-fine powder treatment, while the fine powder discharged from the top of the primary classifier 5 is used by an elbow jet classifier or the like. It is supplied to the next classifier 17. In the secondary classifier 17, the primary and secondary air from the fan 16 and fine powder are sent to carry out classification while placing them on the air flow. A part of the fine powder thus obtained (coarse fine powder) is a bag filter 18
With hopper 19, quantitative feeder 20, conveyor 2
After being secondary pulverized by a pulverizer 22 such as a vertical roller mill through 1, the sheet is returned to the secondary classifier 17. The ultra-fine powder that has been finally ultra-micronized is transferred from the secondary classifier 17 to the collector 23 where it is collected and made into ultra-fine powder as a product. Further, the exhaust air from the collector 23 is blown by the fan 24.
Return to 2. The primary classifier 15 and the secondary classifier 17 may be of the above-described types and are commercially available.

Next, the advantages of the present invention described above will be described more specifically by comparing with the conventional method by the processing flows shown in FIGS. 2 and 3. As shown in FIG. 2, conventionally, in the case of producing fine powder and ultrafine powder from granulated slag, it is general to directly produce from the granulated slag using dedicated mills for fine powder and ultrafine powder. there were. That is, in FIG. 2 (a), for example, from 1000 kg of granulated slag to 1000 k of ultrafine powder with an average Blaine value of 8,000.
Although g was manufactured, in this case, the average power consumption (excluding classifier and fan power) is 82.4KWH / t. In addition, as shown in Fig. 2 (b), 1000 kg of water granules and fine powder with a Blaine value of 4,210
The electric power used when manufacturing 1000 kg was 28.4 KWH / t. Therefore, in the conventional method, ultrafine powder and fine powder are each
The total electric power required to manufacture 1.0t each (ultrafine powder 1.0t, fine powder 1.0t) was 82.4 + 28.4KWH = 110.8KWH.

Next, in the method of the present invention, as shown in FIG. 3, first, 1,000 kg of water granulated slag is pulverized into fine powder (Blaine value = 4200). The power consumption by this crushing is 28.4KWH / t. Next, this fine powder is classified to have a particle size of 7.8 μ or more and less than the same. Particle size
0.6 when the power consumption is allocated to 615 kg of fine powder of 7.8 μ or more
It was 15t x 28.4KWH / t = 17.47KWH (A). Then, this fine powder is re-ground to obtain fine powder 615 having a Blaine value of 4210 as a product.
I got kg. The power consumption at this time is 22.5KWH / t × 0.615t = 1
It will be 3.84 KWH (B). Therefore, the total power consumption in this fine powder manufacturing is 31.31KWH, and the electricity consumption rate is 31.31KWH / 0.615.
It becomes t = 50.91KWH / t.

On the other hand, although 385 kg of fine powder 4 having a particle size of less than 7.8 μ is obtained,
Power consumption to obtain the fine powder 1 (28.4KWH / t) If allocated to the production of the fine powder 4, the power consumption is 0.385t x 28.4KWH / t = 10.93KWH
It was (C). Next, the fine powder 4 is classified (secondary classification) to be classified into a particle size of less than 2.8 μ and a particle size of 2.8 or more. As a product having a particle size of less than 2.8 μ, 92 kg of ultrafine powder 5 was obtained. Also, 293 kg of fine powder 6 having a particle size of 2.8 μ or more is obtained,
This is re-crushed with a small mill, and a fine powder with a Blaine value of 8000 7
And The power for this re-crushing was 24.45KWH / t, so the power consumption was 24.45KWH / t × 0.293t = 7.16KWH (D). Therefore, the power required to manufacture ultrafine powder is (C) + (D) = 18.09KWH, and the power consumption rate is 18.09KWH / 0.385t = 46.99KWH / t.
Therefore, the total electric power required to produce 1.0 t of ultrafine powder and 1.0 t of fine powder by the method of the present invention is 50.91 + 46.99 KWH = 97.4 KWH.

From the above, the total electric power required to produce 1.0 t of ultrafine powder and 1.0 t of fine powder is 110.8 KWH in the conventional method, whereas in the present invention it is 97.9
It was revealed that KWH and power consumption were extremely low.

〔The invention's effect〕

As described above, according to the present invention, only fine powder having a small particle size is passed through the crusher by the primary classification and the secondary classification, so that the capacity of the crusher can be reduced and the power consumption can be reduced. In addition, the related equipment becomes smaller and the equipment cost becomes lower.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a process chart showing one specific example of the method of the present invention, FIG. 2 is a process flow chart of a conventional method, and FIG. 3 is a process flow chart of the present invention method. 3 ... crushing mill (vertical roller mill, etc.), 8 ... silo,
15 ... Primary classifier, 17 ... Secondary classifier, 22 ... Crusher, 23 ... Collector.

Claims (1)

[Claims] 1. When producing ultrafine powder from granulated blast furnace slag, the granulated slag is first pulverized to obtain fine powder, and a part of the fine powder is taken out as a product of cement admixture, and the remaining amount is Fine powder is classified and sieved with a primary classifier based on 5 to 8 μm, coarse fine powder is returned to primary pulverization, fine fine powder is classified and sieved with ultra fine powder and coarse fine powder with a secondary classifier, and ultra fine powder is as it is. Along with commercialization, the coarse and fine powder is secondary pulverized by a pulverizing mill, and then returned to the total amount of secondary classification, and the primary and secondary classification is performed by using a dry air flow,
A method for producing superfine powdered granulated slag, which is characterized in that the primary pulverization and the secondary pulverization are also performed dry.