my country's crude steel production reached 626 million tons, a year-on-year increase of 9.3%, setting a new historical record. However, with the increase in crude steel production, steel slag, the main solid byproduct of steelmaking, is also increasing rapidly. Approximately 75 million tons of steel slag are produced nationwide. If left untreated, it will occupy a large amount of land, pollute the environment, and lead to the waste of scrap steel and slag resources, hindering the sustainable development of the steel industry.

Low Steel Slag Utilization Rate, Equipment Needs Improvement

According to statistics, the effective utilization rate of steel slag in my country is only about 10%, far below the international level. The main reason is that my country's steel slag processing equipment is still inadequate, and existing crushing equipment is not suitable for the characteristics of steel slag, particularly lacking suitable fine crushing equipment for steel slag. Therefore, developing advanced steel slag fine crushing equipment and processing technology has become an urgent problem for steel enterprises. Only through scientific research and overcoming the challenges of steel slag fine crushing can the economic deep processing and comprehensive utilization of steel slag be achieved.

The Importance of Steel Slag Fine Crushing

Recovering More Metallic Iron

Steel slag contains about 7%-10% of scrap steel. Fine crushing can recover more metallic iron. For example, after magnetic separation of steel slag crushed to -75mm, the tailings contain about 4%-6% metallic iron; after magnetic separation of steel slag crushed to -35mm, the tailings contain about 3%-5% metallic iron; when crushed to -10mm and then magnetically separated, the metallic iron content in the tailings can be reduced to about 1%. Clearly, fine crushing is key to improving the recovery rate of metallic iron.

Improving Subsequent Processing Efficiency

Subsequent processing of steel slag usually requires grinding to further separate the scrap steel from the slag. Grinding theory and practice show that the smaller the particle size of the crushed material, the smaller the change in energy consumption per unit, while energy consumption increases sharply when the grinding particle size decreases. Therefore, to reduce energy consumption, a "more crushing, less grinding" process should be adopted, increasing the crushing ratio and reducing the grinding ratio to minimize the particle size of the material entering the mill.

Reducing Grinding Costs

Steel slag that has not been finely crushed has a higher iron content, which affects the mill's output, increases energy consumption, shortens the life of grinding media and liners, and leads to increased costs. Therefore, steel slag needs to be pre-crushed to below 10mm before grinding. Existing Deficiencies in Steel Slag Fine Crushing Equipment

Jaw Crusher

Mainly used for coarse and medium crushing, not suitable for fine crushing. Although some companies use small-scale jaw crushers for fine crushing, the efficiency is low, the effect is poor, and the metal iron recovery rate is only 64.98%.

Roller Crusher

Although it can crush steel slag to -10mm, the product particle size is uneven, energy consumption is high, steel slag splashing affects environmental safety, and maintenance costs are high.

Hammer Crusher

Not suitable for crushing steel slag, suffers from severe wear, has a short service life, and has been phased out by many companies.

Impact Crusher and Vertical Shaft Impact Crusher

Suffers from severe wear and high energy consumption, making them unsuitable for fine crushing of steel slag. Output and particle size are difficult to meet requirements.

Hydraulic Cone Crusher

Although suitable for fine crushing of ore, the high hardness of steel slag and the presence of metal iron inclusions lead to frequent "iron overload" in the equipment, affecting continuity and failing to meet fine crushing requirements.

Rod Mill

Steel rods wear quickly, product particle size is unstable, energy consumption is high, and operating costs are high.

There is still significant room for improvement in steel slag fine crushing equipment and technology in my country's steel industry. By improving equipment and technology, the utilization rate of steel slag can be effectively increased, resource waste can be reduced, environmental pollution can be lowered, and the sustainable development of the steelmaking industry can be promoted.