In mining, the three crushers form a key processing chain. Primary crushers (e.g., jaw crushers) handle large raw ore lumps (1-1.5m), doing rough crushing to reduce volume and lay the foundation. Secondary crushers (e.g., cone crushers) take primary crushed material, conducting medium crushing to refine it to 20-50mm, adapting for next step. Tertiary crushers (e.g., impact crushers) perform fine crushing to 5-10mm finished products, meeting mineral processing or construction needs. They connect closely: primary feeds secondary, secondary prepares for tertiary, ensuring efficient, continuous mining production.