Today, in almost any direction of construction, restoration or repair work, a brand-name cement composition is invariably used. Initially, the dry powdery mixture that this building material represents is a set of binders of inorganic origin. A number of positive properties and characteristics of cement determine the possibility of obtaining concrete or masonry composition, plaster, precast concrete and the like from it.
The key functional ability for which this particular substance is chosen for the manufacture of other compounds is considered to be the ability to quickly harden when mixed with water. Gain the maximum level of strength of the cement mixture can be both in the air and in the underwater environment. It is enough to adhere to an excessive level of humidity.
Many people have carried out the process of direct use of certain cement compounds, but even professionals with a construction education do not fully know what is included in the composition of cement, as well as how it is produced. Next, we will discuss in detail the production of cement, as well as the content of structural elements in it.
Types of raw materials for the production of certain types of cement
When this product is manufactured, special technical conditions are observed, in particular, the proximity of the plant and the deposit, from which a number of structural elements originate. To get such a powder, you can use any of the components listed below:
- Carbonate fossils. These are particularly valuable fossils with a non-standard crystalline or amorphous structure. By their characteristics, they contribute to the fact that the cement mortar will be of high quality, and their chemical capabilities cause excellent interaction with other structural elements of the powder.
- Sedimentary rocks are mainly of clay structural type. Due to these mineral elements contained in the material, the powders increase when moistened, and also retain a plastic structure. Clay is called a viscous mass, which is used when you need to make cement in a dry way.
It is worth taking a closer look at specific examples of fossils in each specific category.
Carbonates
These fossils include:
- chalk is an easily ground limestone powder;
- various marl derivatives are loose or solid fossils that contain structural elements that allow them to be classified as both the first and second raw material categories;
- silicon-free shells with a porous structure;
- Dolomite and carbonate-containing rocks that provide far more than one physical and technical indicator for the powder produced.
Clay-like ones
In this category, you can select:
- clay-thanks to its mineralized base, the powder swells from moisture;
- loam is a clay derivative that has an increased concentration of sand;
- clay-bearing shales are high-strength fossils that have granules of a number of elements and a minimum moisture content in their chemical composition;
- the forest is a small, non-plastic and loose structure, which is characterized by porosity and fine grain, and a certain proportion of its elements is quartz and silicate.
Also, of .
Corrective supplements
However, the cement mixture of masonry consists not only of powder diluted with liquid. Up to 20% of plasticizers can be added to it, providing unique operational capabilities. These include:
- alumina;
- siliceous earth;
- fluorite;
- Apatity, etc.
Compliance with the technology used to prepare the composition in the cement production industry makes it possible to form the following opportunities due to additives::
- corrosion resistance;
- operating temperature in a wider range and tolerance of freezing cycles (the maximum number of them depends on how high the frost resistance is);
- strength parameters;
- mobility and elasticity;
- structure with low moisture permeability.
Important! All this can be achieved only by observing the proportions of the batch. Ask for professional help if you are not sure if the procedures you are performing are correct.
Portland cement: structural ratio of the contained elements
In the described category of building materials, this variety is one of the most popular. The minimum issue grade is M400 (up to M700). Popular powders of this variety:
- slagoportlandtsement;
- fast-setting;
- sulfate-resistant;
- with moderate exothermy;
- hydrophobic;
- plasticized;
- white (color for pigmented filling) , etc.
In its classic version, when grinding, it is possible to obtain a placer consisting of the following elements::
- silicon dioxide (25%);
- lime (60%);
- aluminum (5%);
- iron oxides and gypsum (10%).
Technological features may require changing the proportionate inclusion of these elements, and even expanding their list. For example, slag Portland cement is filled with coal, which is obtained as a residual element when the clinker is fired and then crushed.
The component structure of the powder is formed from these key elements, distributed as follows::
- Clinker granulated placer (almost the entire volume). The element fraction from 1 to 6 cm determines the strength capabilities of the final product. Only after high-temperature processing in furnaces, crushing occurs, which turns this base into powder.
- Gypsum component. Up to 6% gypsum stone or pure fossil determines the curing period of the powder.
- Additional elements that make cement unique in its operational capabilities and parameters.
It remains only to adhere to GOST and TU in order to quickly and efficiently produce powder, the brand of which will meet the highest parameters.
Production diagram
It all starts with mixing the components of the future clinker powder-limestone and clay in a percentage ratio of 75 to 25 percent. Next, the batch is fired under a temperature load of 1450 degrees Celsius. The ball mill mechanism is capable of grinding the granular part of the powder. Moreover, the opposite proportion applies here-the larger fraction corresponds to a smaller brand name as a result.
Technologically, the production procedure can take place in wet, dry or combined form. The selected option determines how the raw material filling will be prepared:
- Wet scheme. Chalk is poured with the rest of the elements into the drum, and liquid is also poured into it-all this in parallel with crushing. This creates a charge with a moisture content of up to 30-50%, which is fired to obtain the main clinker powder (after another stage of grinding).
- Dry. Hot gas is supplied to the mill, which allows not only grinding, but also drying elements.
- Combined version. Two options involve either sequential crushing with drying of the wet charge, or moistening of the already powdery placer.