Limestone, primarily composed of the mineral calcite (CaCO₃), is widely used in construction, agriculture, and industry. Crushing limestone involves reducing its size for various applications. Here’s a breakdown of the process:
1. Crushing Process
– Primary Crushing: Large limestone rocks (from mining/quarrying) are fed into a jaw crusher or gyratory crusher to reduce size to ~6–12 inches.
– Secondary Crushing: Further reduced in a cone crusher or impact crusher to ~1–3 inches.
– Tertiary Crushing: For finer particles (e.g., sand or powder), vertical shaft impactors (VSI) or hammer mills may be used.
2. Key Equipment
– Jaw Crusher: For coarse crushing.
– Cone/Impact Crusher: For medium-fine crushing.
– Hammer Mill/VSI: For fine grinding (e.g., agricultural lime).
– Ball Mill/Raymond Mill: For ultra-fine calcite powder (used in fillers, paints).
3. Challenges & Solutions
– Abrasion: Calcite is moderately abrasive; use wear-resistant liners.
– Dust Control: Wet suppression or bag filters to limit airborne particles.
– Moisture Content: Wet limestone may clog crushers; pre-drying or selecting impact crushers helps.
4. Applications of Crushed Limestone/Calcite
– Construction: Aggregate for concrete, road base.
– Agriculture: Soil conditioner (lime powder to neutralize acidity).
– Industry: Raw material for cement, glass, steelmaking.
– Specialty Usesine-ground calcite in paints, plastics, and pharmaceuticals.
5. Calcite vs. Limestone
– Pure calcite is softer (Mohs 3) than some limestone variants (which may contain harder impurities like quartz). Adjust crushing settings accordingly.
Would you like details on a specific stage (e.g., fine grinding for industrial fillers)?