1. What It Is:
Rock Phosphate is a natural mineral source of phosphorus (P), mined from sedimentary or igneous deposits. It is primarily used as a raw material for manufacturing phosphate fertilizers and also applied directly to soil in some agricultural systems.
2. Chemical Properties:
- Main Component: Tricalcium phosphate (Ca₃(PO₄)₂)
- Phosphorus Content (P₂O₅): Varies from 25% to 35% depending on grade
- Form: Fine powder or rock granules
- Solubility: Low in water, higher in acidic soils
3. Applications:
Agriculture:
- Used as direct application phosphate fertilizer in acidic soils
- Source material for phosphoric acid, SSP, TSP, DAP, and MAP
Industrial Use:
- Production of animal feed supplements, chemicals, and detergents
4. Types of Rock Phosphate:
- Sedimentary: Softer, widely used in fertilizer production
- Igneous: Harder, less reactive, used in industrial processes
- Reactive Rock Phosphate (RPR): More effective for direct soil use
5. Advantages & Limitations:
- Natural and slow-releasing phosphorus source
- Environmentally friendly option in organic farming
- Less effective in neutral or alkaline soils due to low solubility
6. Storage & Handling:
- Store in dry areas to avoid caking
- Often requires grinding or processing before use
