Which milling mechanism involves the use of grinding surfaces to reduce particle size?

The correct mechanism involving the use of grinding surfaces to reduce particle size is abrasion. This process involves the mechanical action of particles rubbing against each other or against a hard surface, leading to the wearing away of the material and size reduction. In milling applications, abrasion occurs when materials are subjected to friction, derived from the movement and contact between particles and the grinding surfaces, such as in a ball mill or a similar device.

Understanding the context of other milling mechanisms helps clarify why abrasion is the correct choice. Impact relies on the high force of collision to break down particles quickly, rather than through sustained surface-to-surface contact. Compression involves applying pressure to reduce particle size, which can cause the material to fracture but does not primarily depend on grinding surfaces. Shear forces act parallel to the particle surface and can also lead to size reduction, but it primarily relies on slicing or tearing rather than grinding. Therefore, abrasion, through its focus on friction and grinding surfaces, is the distinctive mechanism in this context.