How is crushing different from grinding in ore processing?

In the context of mineral processing, crushing and grinding are both stages of comminution—the physical process of breaking down ore to liberate valuable minerals from waste rock.1

The primary differences between the two processes include:

• Purpose and Size: Crushing is the initial stage of size reduction, typically breaking hard rock masses into smaller, manageable pieces. It is performed in stages (primary and secondary) to produce a material suitable for mill feed, usually less than 10 to 14 millimetres in diameter. Grinding follows crushing and is the final stage, reducing the ore into a fine powder. The required fineness of this powder is determined by how finely the desired mineral is disseminated within the ore.21
• Operational Conditions: Crushing is almost exclusively performed under dry conditions. In contrast, grinding mills can operate under both dry and wet conditions, with wet grinding being the predominant method used in modern industry.1