In the green transformation of the modern steel industry, ball mills play a pivotal role, serving as the core equipment for transforming steelworks waste into valuable resources. Steel plants generate vast quantities of steel slag during their production processes; yet, within this seemingly useless waste lie abundant reserves of iron concentrate as well as active components suitable for use in construction materials.

The operating principle of a ball mill is both scientifically sound and highly efficient. It primarily consists of a horizontally positioned, rotating steel cylinder lined with wear-resistant plates and charged with steel balls or segments of specific dimensions. As the cylinder rotates, the internal grinding media are lifted to a certain height by the combined forces of centrifugal force and friction; subsequently, under the influence of gravity, they cascade downward. Acting like projectiles, these grinding media exert intense impact and abrasive forces upon the steel slag fed into the cylinder, thereby pulverizing it.

In practical waste treatment processes, steel slag—having undergone preliminary crushing and magnetic separation—is fed into the ball mill for fine grinding. Depending on the specific characteristics of the material and the method of discharge, ball mills are broadly classified into two types: dry mills and wet mills. The steel slag powder produced by this fine grinding process possesses an extremely fine particle size; not only does this allow for the further extraction of high-grade iron concentrate via magnetic separation, but the remaining fine powder also serves as a high-quality, highly reactive admixture for the production of cement and concrete. The application of ball mills has truly realized the goal of zero-emission waste management and resource recovery for steel slag, thereby providing a definitive solution to the environmental pollution issues historically associated with such industrial waste.