Comparison of Three Different Processes for Slag Micro-powder Processing

With the continuous advancement of ultra-fine crushing technology, the processing technology of ultra-fine slag powder is also constantly upgrading. This article compares and introduces the processing technology of several commonly used domestic slag powder. Enterprises can choose the appropriate one according to the actual production needs. Production Process.

Ball mill processing slag powder technology

Process introduction

The dried slag is sent to the mill through the metering and feeding equipment, and is ground into fine powder in the mill. If necessary, a fine grinding classifier can be added in the mill to improve the fineness of the product. Delivered to finished product warehouse. In order to produce products with high specific surface area, a superfine classifier can be configured in the system. The specific surface area of the product produced by the ball mill equipped with a superfine classifier can reach 1000㎡/kg.

The slag micropowder is produced by a ball mill, the fineness adjustment is more flexible, and the particle shape and gradation of the slag micropowder are better. In the case of the same specific surface area, the quality of the ball mill product is better than that of the vertical mill, and the corresponding strength is also good, but the power consumption is higher when the ball mill is used to produce slag powder.


Process selection

There are two options for producing slag powder with ball mills: open circuit and closed circuit. The open circuit process is simple and the investment is relatively low, but the output is low, and it is difficult to produce products with high specific surface area. Although the investment of closed circuit is large, the fineness can be adjusted flexibly, which can effectively overcome the phenomenon of over-grinding, and can produce products with high specific surface area. Therefore, when using a ball mill to produce slag powder, if conditions permit, a closed-circuit system should be preferred. For cement production with a mill with a relatively large length and diameter, an open-circuit system is more appropriate.

Device Configuration

There are mainly ball mills, powder separators, dust collectors and fans. Among them, centrifugal powder separator and cyclone powder separator are not suitable for the production of slag fine powder, because when these two types of powder separators are used to produce slag fine powder with high specific surface area, the powder separation efficiency is too low and the cycle load rate is too large , uneconomical, so vortex separators should be used. The following is the configuration of the production line with an annual output of 120,000 tons of slag powder.

Vertical mill grinding process

The process of producing slag micropowder by vertical mill is relatively common in recent years, and has developed rapidly, and is preferred by various iron and steel companies. Due to the advancement of science and technology, the vertical mill gradually overcomes the shortcomings of vibration and material wear, and is gradually used in the production of slag powder. The specific surface area of its products is generally 420-450㎡/kg, but generally not more than 500㎡/kg. Otherwise, it is easy to aggravate the wear and vibration of grinding parts such as grinding discs and grinding rollers.

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Process flow

Generally, the belt conveyor is used to directly transport the slag from the slag yard to the wet slag bin in the factory area. The wet slag bin should not be too large. Generally, the storage capacity is required to be sufficient for 4 to 8 hours, so as to prevent the wet slag from agglomerating and blocking the material if it is not used for a long time. . When the source of slag is single and the quality is stable, a 22mX45m homogenization warehouse can be built. When there are many sources, two 18m or three 15m homogenization warehouses need to be built to ensure stable product quality. Slag fine powder is directly used in concrete mixing plants, and is generally transported by bulk trains, bulk trucks, and bulk ships. If it is really necessary to use packaging bags, it must also be packaged in large bags (tons of packaging), not small bags to reduce costs.

When this scheme is adopted, high input and high output can be achieved, and economies of scale can be formed. The technological process is relatively complicated, but the operation and maintenance requirements of the mill are relatively high, and the investment is also high. This program is mainly suitable for improving product grades and new production lines of a certain scale.

Vibration mill grinding process

Vibration mill is a new type of grinding technology equipment developed in recent years. This equipment has the advantages of small footprint and simple equipment structure. When using this scheme, only the vibration mill is used to replace the ball mill, and the other processes are roughly the same. Due to the limitation of the specifications of the mill, large-scale production cannot be formed.

From the above comparison, it can be seen that through the transformation of the ball mill for production, it has the advantages of low investment, high output, simple operation and maintenance, and easy production management, so it is a better choice. If large-scale production is to be formed, the vertical mill scheme is an ideal grinding process.