The production process flow of Messebo Cement Factory (located in Ethiopia) follows the dry process method, which is energy-efficient and commonly used in modern cement plants. Below is a step-by-step breakdown of the cement manufacturing process at Messebo:
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1. Raw Material Extraction & Preparation
– Quarrying: Limestone (primary raw material), clay, shale, gypsum, and other additives are mined from the quarry.
– Crushing & Pre-homogenization:
– Raw materials are crushed into smaller pieces (using crushers).
– Stockpiled and homogenized to ensure consistent chemical composition.
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2. Raw Meal Grinding (Raw Mill)
– Crushed raw materials are ground into a fine powder in a vertical roller mill (VRM) or ball mill.
– A homogenizing silo ensures uniform blending before kiln feeding.
3. Preheating & Pre-calcination (Preheater Tower & Calciner)
– The raw meal passes through a 4-6 stage preheater cyclone tower, where hot gases from the kiln heat it to ~900°C.
– In the calciner, ~90% of limestone (CaCO₃) decomposes into lime (CaO) and CO₂ before entering the kiln.
4. Clinker Production (Rotary Kiln)
– The preheated meal enters a long, rotating kiln (~1450°C).
– Chemi
reactions form clinker (small, dark gray nodules) through sintering.
5. Clinker Cooling (Grate Cooler)
– Hot clinker exits the kiln and is rapidly cooled in a grate cooler.
– Recovered heat is reused in the kiln/preheater for efficiency.
6. Cement Grinding (Cement Mill)
– Clinker is mixed with gypsum (~5%) and additives (e.g., pozzolana, slag).
– Ground into fine powder in a ball mill or vertical roller mill to produce cement:
– OPC (Ordinary Portland Cement)
– PPC (Portland Pozzolana Cement)
7. Storage & Packing
– Cement is stored in silos for quality control before dispatch.
– Packaged in bags (~50kg) or loaded as bulk for transport