In the context of a green circular economy, how to turn waste into treasure for industrial solid waste has become a key issue. Among these, the deep resource utilization of blast furnace slag relies heavily on a core piece of equipment the vertical roller mill.
In the building materials and metallurgical industries, the vertical roller mill (also known as a slag vertical mill specifically designed for grinding slag) has long been the preferred technology for processing blast furnace slag and achieving resource utilization. It is not merely a simple crushing device, but an industrial production line integrating high-efficiency grinding, drying, and powder selection. This article will provide a comprehensive understanding of this highly efficient and energy-saving slag grinding solution.
I. More Than Just Crushing: How Does the Vertical Roller Mill Turn Slag into Gold?
The working principle of the vertical roller mill can be summarized as integrated operation, with its core process being the organic combination of crushing, drying, and powder selection.
1. Feeding and Spreading: The initially crushed lumpy slag is continuously fed into the center of the high-speed rotating mill disc, where it is evenly spread under centrifugal force, forming a uniform material bed.
2. High-Pressure Compaction: Two to four grinding rollers mounted on the grinding disc, under immense pressure provided by a hydraulic system, compact the material onto the material bed. The material is not crushed, but rather compressed and ground; this bed grinding principle boasts extremely high energy efficiency.
3. Simultaneous Drying: Simultaneously with compaction, hot air (usually from a matching hot air furnace) introduced from the bottom of the mill penetrates the material layer. The hot air both blows up the finely ground material and simultaneously dries any residual moisture in the slag.
4. High-Efficiency Sorting: The powder carried by the hot air rises to a dynamic separator at the top. The separator acts like a precision sieve, classifying the particles: finely ground slag powder is discharged with the airflow as the product; coarser particles fall back to the grinding disc for regrinding.
Through this series of precisely coordinated processes, the vertical roller mill successfully transforms industrial waste that previously required landfilling into high-value-added, high-quality slag powder.
II. Why is the Vertical Roller Mill the Preferred Choice for Slag Treatment?
Compared to traditional ball mills, vertical roller mills exhibit overwhelming advantages in slag grinding, primarily in the following aspects:
• Superior energy efficiency: Utilizing a bed-feed grinding principle, it saves 30%-50% more electricity than traditional ball mills, significantly reducing production costs.
• Powerful drying capacity: It can directly process slag with high moisture content, eliminating the need for a separate drying system and space, simplifying the process flow.
• Excellent product quality: A dynamic separator allows for precise control of the finished product's fineness, resulting in slag powder with a reasonable particle size distribution and high activity, further enhancing concrete performance.
• Small footprint: The compact, vertically oriented structure occupies significantly less space than ball mill systems.
• Environmentally friendly: The equipment operates with low noise, has excellent overall sealing, and dust emissions are far below environmental standards.
III. Where is the slag powder produced by vertical roller mills applied?
Slag powder processed by a vertical roller mill is a key raw material for achieving green building materials, primarily used in:
• High-performance concrete: As a high-quality admixture, it significantly improves the durability, strength, and corrosion resistance of concrete, and is widely used in large-scale infrastructure projects.
• Cement production: As a blending material, it is co-ground with cement clinker to produce slag silicate cement, reducing cement production costs and improving performance.
• New building materials: Used in the production of slag bricks, blocks, etc., utilizing solid waste and promoting the development of a circular economy.
Vertical roller mills (slag vertical mills) are no longer just simple grinding equipment; they are core technological equipment for promoting the resource utilization of industrial solid waste and helping the building materials industry achieve its dual carbon goals. Their high efficiency, energy saving, and environmental protection characteristics ensure their unshakeable market position in the slag treatment field. Investing in an advanced vertical roller mill means choosing a win-win path of economic and environmental benefits.
If you are planning a slag resource utilization project, choosing a suitable vertical roller mill will be a crucial step to success.
