In mineral processing and grinding processes, ball mills are one of the key pieces of equipment, and steel balls, as the main grinding medium, have specifications that directly affect grinding efficiency, energy consumption, and product quality. The rational selection of steel ball specifications requires comprehensive consideration of factors such as ore properties, feed particle size, product fineness requirements, and ball mill structure.

Generally, larger diameter steel balls (e.g., Φ80–Φ120mm) are suitable for the coarse grinding stage due to their strong impact force, which effectively breaks down large ore particles; while smaller diameter steel balls (e.g., Φ30–Φ60mm) should be used in the fine grinding stage to increase the grinding contact area and improve fine grinding efficiency. If the ore is hard and coarse-grained, larger steel balls are needed; conversely, for soft or fine-grained materials, the steel ball diameter should be reduced to avoid over-grinding and energy waste.

Furthermore, multi-stage grading is often used in actual production, meaning that different sizes of steel balls are mixed to balance impact and grinding effects. For example, in a single-stage grinding process, Φ100mm, Φ80mm, and Φ60mm steel balls can be combined in appropriate proportions to form a reasonable grading system and improve overall grinding efficiency.

It is also important to note that the material of the steel balls (such as high-chromium cast iron, forged steel, etc.) affects their wear resistance and service life, and should be selected appropriately based on working conditions. In short, steel ball specifications are not fixed and should be continuously optimized through testing and production data to achieve efficient, energy-saving, and stable grinding operations.