Cement - one of the main materials in the construction, it is a special astringent of mineral components, which when solidified form a very strong, solid material.
Cement is produced from various raw materials depending on the region.
The main raw materials for cement production
Cement is made of special cementClinker, which is the result of firing the main mineral raw material, mined in natural conditions or manufactured by artificial methods. Raw materials for cement can be clay and carbonate rocks.
Clay rocks are clay, loam, loess,Clay slate, loess-like loam and other rocks. Clay with the addition of moisture swells and becomes plastic, which is important for high-quality cement. All these types of clay rocks differ slightly in their properties. For example, loam contains many sandy substances, and clay shales are dense and solid, composed of plates, have less moisture. The loess is porous and loose, it contains quartz, feldspar and other materials.
Carbonate rocks include chalk,Limestone, marl and other limestone, carbonate and dolomite materials. Depending on the composition, properties and quality of this raw material, cement with different characteristics is obtained.
For example, crystalline rocks are worse for cement production, since they interact with other elements during firing.
Most often, cement is used for chalk,Which is easily ground and crushed. Mergel is used for the production of cement, which is necessary for the installation of fireplaces and stoves: this material is a transition between clayey and limestone. In addition to the main raw materials, additional ingredients are added to the cement, which change the properties of the product.
This can be gypsum, fluorite, sodium, apatite, phosphogypsum and other materials, as well as aluminous, clay-containing additives.
The first stage of cement production - manufacturingClinker from the main raw material by firing. This is the most expensive stage, as the extraction of materials takes about 70% of the cost of manufacturing cement. In order to find the right breeds, it is necessary to demolish the upper part of the limestone mountain (usually with the help of dynamite) and open the rock layer, which is usually found at a depth of 10 meters. The extracted material is ground, mixed with additives and calcined.
Further clinker is still ground with heavy steelBalls, until it turns out a powder that needs to be dried well, then the rest of the ingredients are added to it - this is the second stage of the cement production process.