How to Minimize the Dry Method Cement Factory Cost

The cement industry is a capital-intensive and resource-intensive industry. With the convenience of international trade, overcapacity in production, rising investment, and other existing factors, many cement enterprises are suffering from increasing pressure to become more profitable. However, one of the main factors contributing to the success of an enterprise is the reduction of production costs. Sustainable cost reduction is also important for the development of cement factories. So, how to minimize the production cost has become a crucial issue.

Dry method cement production is the most common cement manufacturing process in the cement industry. AGICO, as a cement plant equipment supplier in China, has been professional in building dry method cement plants for more than 20 years. Based on our experience and achievements, we believe that minimizing cement factory costs can be realized at each stage of the cement production process. For understanding, there is a cement manufacturing flow chart illustrated below:

Overall, if you want to reduce the plant cost, you can start with three aspects:

• Site selection
• Cement equipment selection
• Cement factory layout

Next, we will further talk about the cost reduction methods from the three aspects mentioned above.

Site Selection

The site selection determines the construction and operating costs of a cement factory and is difficult to change once selected. Therefore, we should be careful about it, which requires multiple surveys and repeated comparisons. Generally, site selection should be based on the following principles:

• It’s better to have the most economical logistics transportation.
• The geology of the site is suitable for constructing a cement plant.
• The factory site is away from environmentally sensitive areas and densely populated areas.
• It is in line with the master plan of the local government.
• Space should be large enough for further expansion.
• It is best to have a limestone mine near the site with a certain amount of reserves and meet the quality requirements.

All of these principles will help us to save unnecessary investment.

Cement Equipment Selection

As we all know, the cement manufacturing processes can be roughly divided into three stages: raw material preparation, clinker calcination, and cement grinding. To complete these processes, we need plenty of cement equipment. They will not only affect the cost in the early stage but also affect the energy consumption and production efficiency in the subsequent cement manufacturing.

Raw Material Crushing

Cement crushers we commonly use include:

• Cone crusher
• Jaw crusher
• Hammer crusher
• Impact crusher

In the early days, we usually adopt a two-stage crushing system with a jaw crusher as the primary crusher and a hammer crusher as the secondary crusher. Compared with two-stage crushing, the large-capacity crusher applied in a single stage is more expensive. However, with more mature technology appearing, large production capacity requirements, and increasing plant scale, we find that the use of single-stage crushers will lower investment to some extent, saving in power consumption and material handling. The single-stage hammer crusher and roller crusher are both good crusher models.

Raw Material Grinding & Cement Grinding

Cement ball mill and vertical roller mill are two grinders commonly used for cement grinding and raw material grinding. Compared with conventional ball mills, the vertical roller mill and the ball mill with high-efficiency separator are more energy-saving. Especially for the vertical roller mill, the motor only consumes about 7 – 8 kWh/ ton.

Clinker Calcination

Clinker calcination can be divided into preheating, precalcining, burning, and cooling, four steps. It is the most important thermal energy consumption part of the cement plant. The preheater, precalciner, cement kiln, and cement cooler are the equipment we mostly use in this stage. With the development of technology, the transfer from the wet method to the dry method of cement manufacturing reduces thermal energy. Next is the upgraded addition of a suspension preheater and precalciner. Their heat consumption is shown in the following table:

Therefore, the 4-6 stage suspension preheater plus precalciner and cement kiln is the most energy-saving structure for clinker calcination. The production cost will be reduced accordingly.

Cement Factory Layout

Cement factory layout has a significant effect on the total energy consumption and civil engineering cost. So preparing a reasonable and effective layout design is crucial before establishing a cement factory. In principle, the more compact the layout of a cement plant, the lower the investment, as a compact layout design can reduce the land cost, shorten the distance of conveying equipment and material transfer distance, and decrease the number of wires, cables, and water supply lines. Besides, an approach of good design approach would include:

• Make full use of the terrain to shorten the distance between the equipment and the workshops.
• Place the equipment in the open air as much as possible. This is the most direct way to reduce costs. Actually, in addition to considering the noise problem of the cement plant equipment, all the main or auxiliary machinery can be placed in the open air. This not only reduces the number of buildings but is also convenient for equipment maintenance.
• Adopt mechanical conveying instead of pneumatic conveying.
• Avoid the transfer towers for the belt conveyors.
• Set the coal mill near the preheater, because preheater exhaust gases can be utilized inside the mill.

The aspects discussed above are of the most critical nature. As someone new to building a dry method cement factory, you can reduce the total investment by controlling these areas. Although cost reduction is possible in other areas as well, it requires us to continuously explore and summarize.