Both the grinding plant and cement plant have the same goal, which is producing the finished cement. However, they are quite different from many perspectives such as the manufacturing process, the production equipment, the choice of plant location, etc. In a narrow sense, the grinding plant is only one part of the cement plant. Normally, it costs much more to set up the cement plant than the grinding plant. The energy consumption of a grinding plant is less than a complete cement production line. Cement industry statistics show that the power consumption of a grinding plant takes up about 65%一75% percent of the cement plant.
Investment
A large amount of capital is needed when setting up a cement plant. Cement plants cost one billion to several billion is common to see which is too high for a small enterprise to set foot in. Besides， it might take two to three years to build up a cement plant. The return on investment needs a longer time compared with the cement grinding plant.
The cement grinding investment is small and more flexible. To set up a cement grinding plant, the starting point is estimated to be tens of millions of dollars. By adding the number of investments, the production capacity is greatly increased. According to a project by SINOMA, when the investment is 1 billion, the output of finished cement is about 4.4 million tons per year. What’s more, compared with the cement plant, the grinding plant requires a smaller area, and the cost is correspondingly saved. If you decide to set up a new type of modular grinding plant, the floor space is further saved. And the civil engineering work is less. Most importantly, the payback is as short as 1 to 2 years.
Manufacturing process
The whole process of a cement plant mainly includes raw material grinding, raw material calcination, clinker grinding, packaging, etc.
The first stage is raw meal grinding. Lime-based raw materials, clay-based raw materials, and a small amount of calibration raw materials (a certain amount of coal is also added in shaft kiln production) are crushed or dried. Then they are mixed in a certain proportion, ground, and prepared into raw materials with suitable composition and uniform quality.
The second stage is clinker calcination. The raw meal is added into the cement kiln and calcined to partial melting to obtain cement clinker with calcium silicate as the main component.
The third stage is cement grinding. A proper amount of gypsum is added to the clinker, and sometimes some mixed materials are added. They are ground together to form cement.
The manufacturing process of a grinding plant is simpler which only requires the third stage of the cement plant. Cement grinding plant is an industry with green benefits. The main production process is to grind clinker, gypsum, and mixed material together to a specified fineness to make cement. There are many kinds of mixed materials, the common ones are fly ash, slag, mineral powder, limestone, and so on. Since most of the mixed materials come from waste residues produced in cities, cement grinding stations are usually built near cities so that materials can be obtained locally. This is also an advantage for small businesses.
Equipment
Equipment in the cement plant
1. Crushing Equipment
Jaw crusher, hammer crusher, impact crusher, etc.
2. Conveying Equipment
belt conveyor
3. Grinding Equipment
air-swept coal mill, slag mill, cement mill, raw mill, etc.
4. Calcination Equipment
cyclone preheater and cement rotary kiln are generally used
5. Cooling equipment
Such as single cylinder cooler
6. Dust removal equipment
air box pulse bag filter can be selected
7. In addition, it is necessary to add equipment such as a separator and cement bulk machine.
Equipment in cement grinding plant
1. Cement mills such as cement ball mills, vertical roller mills, roller press
2. Cement mill separator
4. Filter bag
5. Cement conveyor
6. Cement packing machine
7. Cement silo
Location
Generally, the cement plant is located near the limestone mine. Because limestone is the most important raw material for a cement plant. If the cement plant is built near the city, the transportation cost will be increased by 60% since each ton of clinker needs about 1.6 tons of raw material.
The location of the cement grinding station is usually near large and medium cities, that is, close to the cement sales market. The reason is to reduce transportation costs since most of the mixed materials are waste slag produced by the city. Because it is close to the city, the cement grinding station conveniently serves the cooperation of concrete companies and other types of cooperation, which accelerates the progress of urban construction.
Conclusion
In conclusion, the grinding plant has many advantages over the cement plant. The total cost for land, raw material, equipment, civil engineering, and energy consumption is less. It is friendly to new investors since the recovery of cost is quicker than the cement plant.
