The production of 1 ton of cement requires a variety of raw materials, depending on the type of cement and manufacturing process (wet or dry). Here’s a general breakdown:
Key Raw Materials for 1 Ton of Cement:
1. Limestone (Calcium Source) – ~1.2 to 1.5 tons
– Main component (~60-70% of raw mix).
– Provides calcium oxide (CaO).
2. Clay/Shale (Silica & Alumina Source) – ~0.2 to 0.3 tons
– Supplies silica (SiO₂), alumina (Al₂O₃), and iron oxide (Fe₂O₃).
3. Iron Ore/Pyrite Ash (Iron Source, if needed) – ~0.02 to 0.05 tons
– Adjusts the iron content for clinker formation.
4. Sand/Silica (if additional SiO₂ is required) – ~0.05 to 0.1 tons
– Used if clay lacks sufficient silica.
5. Gypsum (for final cement grinding) – ~0.03 to 0.05 tons (~3-5%)
– Added during clinker grinding to control setting time.
6. Alternative Materials (if used):
– Fly ash, slag, or pozzolans may replace some clinker in blended cements.
Process Losses & Adjustments:
– About 30-40% weight loss occurs during calcination (CO₂ release from limestone).
– Final cement output is ~60-70% of raw meal input.
Typical Raw Meal Composition for Clinker:
| Oxide | % in Clinker |
|———-|————-|
| CaO | 60-67% |
| SiO₂ | 17-25% |
| Al₂O₃ | 3-8% |
| Fe₂O₃ | 0.5-6% |
Energy & Fuel Requirements:
– ~4 GJ of thermal energy (~110 kg coal equivalent).
– ~90 kWh electricity for grinding and processing.
Would you like details on a specific cement type (e.g., Portland, PPC)?