Cement is indispensable when it comes to building and construction. It is an essential construction ingredient and also the most popular among construction and building experts. We shall discuss extensively on cement milling, i.e. the manufacturing process involved in making cement.
Cement is essential because it is the only material that can enhance concrete’s viscosity, because of which the concrete presents a stable locking of gravels and sand for a perfect concrete mix.
Cement Manufacturing Process Phases
Cement production undergoes the following phases to be considered as a finished product. The stages it involved are:
The extraction of raw material/quarry
The proportioning, blending and grinding
The pre-heater phase
The Klin phase
The cooling and Final grinding
the packing and shipping phase
Cement Manufacturing Process
Phase 1: The extraction of raw material/quarry
Raw materials that include silicon, aluminium, calcium, and iron are what is used in cement production. Sand, limestone, and clay make up the raw materials that are required for cement production. Calcium is derived from lime which is also mixed with minute quantities of clay and sand. On their own, clay and sand suffice for aluminium, silicon, and iron.
Furthermore, it is essential that there is reasonable proximity between cement plants and limestone quarry. As raw materials are extracted from the quarry, they are brought to the cement plant unhindered. This is done majorly for convenience and because it is cost effective. Therefore, proximity to the source of raw materials is an important factor when considering cement milling.
Different types of raw materials can be chosen for cement manufacturing like the fly ash, bauxite, and mill scale types. Due to their little requirements in cement milling, the raw materials are extracted directly from other sources.
A crusher at the site of quarry does the crushing of rocks into smaller quantities before they can be conveyed to the cement plant. The crusher can crush big sizes of rocks as well as Rick’s that are as small as gravels.
Phase 2: The proportioning, blending, and grinding
At the plant laboratory, materials from the quarry are examined, and the right amount of clay and limestone are mixed before the beginning of grinding. By usual practice, limestone accounts for 80% and clay accounts for 20%.
At this stage, the mixed raw materials will undergo grinding through the rotating table and the heavy-wheel type rollers. The rotating table’s job is to repeatedly rotate the roller and help it to contact the roller. To finish the process, the roller crushes the material to a powder. After that, the raw mix is stored in a pre-homogenization pile.
Phase 3: Pre-heating raw material phase
The preheating chamber is the next stop after the final grinding. In the preheating chamber is the vertical cyclone where the raw material threads before it moves to the kiln. The process in the preheating chamber is eco-friendly as it conserves energy well.
Phase 4: Kiln Phase
The Kiln is a massive rotating furnace involved in cement milling. In the Kline, raw materials are heated to about 1450 degree Celsius which initiates decarbonation. Chemical reactions between silicon dioxide and calcium compounds make the main ingredient of cement. What klin does is to heat up the exit flanks through coal and natural gas. A clinker shape is formed as soon as materials reach the klin’s lower section.
Phase 5: The cooling and final grinding
Leaving the Klin, the clinkers are cooled by intensified air then they attain a low temperature by releasing the absorbed heat. Meanwhile, the released heat is recycled by the klin to conserve energy.
Then the concluding part that is the grinding. A horizontal shape laced with steel balls is involved here too. The clinkers pass through a rotating depth upon cooling. Steel balls move and hit the clinker into a powdery form. The powdery form is what cement turn out to be. A little amount of gypsum is added in the course of the grinding which maintains the cement’s form.
Phase 6: The packing and shipping phase
Silos harbour the materials from the grinding mills. Also, about 20-40 kg bags can be held by a silo, and only a fraction of cement percentage is packed in the bags just for consumers who demand little amounts. The rest of cement is then shipped to distributors and agents in large quantities via trains, trucks, ships and by air, sometimes.
Cement milling is an exciting process that involves different methods and practices. We have encountered good practice such as the conservation of energy and materials at varying phases of cement manufacturing.