Vertical roller mill

Blast furnace slag has high hardness and abrasiveness. If ordinary materials are used to make grinding rollers and grinding disc liners, the wear rate will be accelerated, resulting in increased equipment maintenance frequency and affecting production efficiency. The use of high chromium alloy or cladding wear-resistant materials can effectively extend the service life of grinding rollers and grinding discs, usually up to more than 30,000 hours, which is about 50%-70% higher than ordinary materials

In view of the high hardness of blast furnace slag particles, the hydraulic system design of the vertical mill adopts higher hydraulic pressure to ensure that the grinding roller can apply sufficient grinding force to achieve efficient grinding. Advanced pressure regulation control technology can also automatically adjust the pressure according to the different hardness of the slag material to ensure the stability of the production process and grinding efficiency. Under normal circumstances, the hydraulic system can increase the grinding force by 10%-15%.

When grinding blast furnace slag, due to its high fine powder generation rate, the airflow classification system of the vertical mill is optimized to enhance the separation effect of fine powder. Efficient airflow classification can ensure the uniform fineness of the ore powder, and usually ensure that the fineness of the product is within the range of 400-450m²/kg of specific surface area. This can improve product quality, avoid fine powder returning to the grinding disc too early, and reduce equipment wear.

Blast furnace slag contains a certain amount of moisture, so the heat source system of the vertical mill usually uses a high-efficiency hot air furnace to dry the material during the grinding process. This heat source system can be equipped with an independent boiling furnace by introducing high-temperature flue gas from the rotary kiln. Through this design, the thermal energy utilization rate of the vertical mill can be increased by 15%-20%, so that the unit energy consumption is controlled within 25-30kWh/ton, which greatly reduces the production cost.

When processing blast furnace slag, the slag vertical mill effectively reduces dust emissions through labyrinth seals and dust collectors equipped with chamber spraying. The dust emission of the vertical mill can be controlled below 30mg/Nm³

The incorporation of slag can significantly improve the overall properties of cement, especially in terms of strength and durability. The active ingredients in the slag can react with the calcium hydroxide generated by the hydration of the cement to form more calcium silicate hydrate (C-S-H) gel, thereby enhancing the strength of the cement.

Research shows that the compressive strength of cement mixed with 30% slag can be increased by 10%-15% in 28 days. In addition, slag cement has better density and can reduce internal porosity, thereby significantly improving impermeability and resistance to chemical corrosion, especially in terms of resistance to sulfate attack. At the same time, slag cement has a low heat of hydration and is particularly suitable for large-volume concrete projects. It can effectively reduce the internal temperature rise of concrete, reduce temperature stress, and prevent cracking. This is especially important for construction in high-temperature seasons or large-volume projects.

In terms of economic benefits and environmental protection, slag cement also has significant advantages. The incorporation of slag can reduce the amount of clinker in cement, usually saving 10%-30% of clinker. This not only reduces production costs, but also reduces energy consumption and carbon dioxide emissions, and has significant environmental benefits.

At the same time, slag cement has good fluidity, strong operability during construction, reduces bleeding, and has good water retention, which can effectively prevent early dry shrinkage cracks in concrete. In addition, slag cement can also reduce the demand for limestone resources, consume a large amount of industrial waste, and reduce carbon dioxide emissions by 20%-30%, which is of great significance to achieving the goal of carbon neutrality.