Cement

Raw materials such as limestone, clay, and marl are extracted at the quarry and prepared for transport to the plant. Generally, there are no dust collection systems.

In the crusher, the raw material is crushed into smaller, manageable particles. A dust collector may be installed here to extract dust from the crusher, the conveyor belt, and all transfer points. (Transfer point = the point where material is transferred from one system to the next.)

Various raw materials are temporarily stored and mixed here to achieve the most uniform composition possible. 
Although not typical, some plants may have a general dust extraction system that removes dust from the hall where the material is stored and pre-homogenized. 

In the raw meal mill, the raw materials are finely ground to produce a homogeneous raw meal for further processing. A large dust collector is almost always installed here to extract dust from the mill as well as from all transfer points, such as conveyor belts, bucket elevators, etc.

The raw meal is temporarily stored in silos and blended to compensate for fluctuations in its composition. Typically, this involves a single silo that serves both to store and to blend the material. It is usually equipped with an integrated dust extraction filter at the top of the silo.

In the preheating tower, the raw meal is preheated by hot process gases before it enters the kiln. The preheating tower itself typically does not have a dust collector. The gases coming from the rotary kiln are directed to the main filter at the top of the preheating tower.

The furnace bypassdiverts a portion of the furnace exhaust gases away from the process to remove unwanted substances such as chlorine or alkalis. The duct used to remove chlorine and alkali compounds is typically equipped with cyclones and a filter.

In the coal mill, the fuel coal is processed to the fineness required for combustion.The size of the coal mill can vary depending on the country and the proportion of coal used as fuel. A dust separator is installed in this area.

For example, plastic grinding systems can be equipped with dust collectors on conveyor belts and grinding units, particularly when ATEX requirements apply.

In the rotary kiln, the preheated raw mealis fired at very high temperatures and converted into clinker.Dust removal from the rotary kiln is carried out via a central filter. An important factor is the exhaust gas stream at the outlet of the preheating tower, which has temperatures ranging from approximately 300 to 380 °C. These gases are often cooled to 160 to 220 °C; electrostatic precipitators or pleated bag filters are then used at this point. Depending on the temperature range, suitable solutions can be offered in certain cases.

In the clinker cooler, the hot clinker is rapidly cooled after firing, and some of the heatis recovered.A large pleated bag filter is typically installed here. Depending on the maximum operating temperature, suitable solutions can be offered in some cases.

After cooling, the clinker is temporarily stored before being processed further.Transfer points and silos may be equipped with a dust collection system or multiple dust collectors.

Here, clinker is ground very finely along with other components to produce cement.This is one of the largest dust collectors in the plant. It can also handle dust extraction at transfer points.

Additives such as granulated blast furnace slag, limestone, or fly ash are stored in these silos.These silos may be equipped with built-in filters for ventilation.

During separation, the ground material is divided into fine and coarse fractions to achieve the desired product quality.Typically, a separate dust collector isprovided for the separator.

The finished cement is stored in silos before it is packaged or loaded. The silos are typically equipped with built-in filters. In addition, there may be a separate dust collection system for the transfer points.

Raw materials, intermediate products, and finished products are tested and analyzed in the laboratory. The laboratory is typically equippedwith small dust collectors, eitherwith cartridge filters,pleatedbag filters, or Flat cell filters. 

Here, the cement is bagged and prepared for shipment.Transfer stations and bagging machines are equipped with medium- or small-scale dust collection systems.

At thebulk loading station, loose cement is loaded directly into silo trucks or other transport units.Transfer points and loading stations are equipped with amedium-sized or largerdust collection system, especially when there are many or large loading points.