Cement as a building material. How cement is made

In our article we would like to talk about the amazing building material from which numerous concrete structures, house walls, bridges, foundations, small architectural forms and similar structures are made. We're talking about cement. As is known, cement is construction material Not natural origin.
The production of this sought-after material is a very expensive and energy-intensive process, but what comes out is worth it in the end. Cement, as a rule, can be used separately, or can be a component of another building material, for example, concrete. Production plants are usually located right where the raw materials needed for the preparation process are obtained, so as not to incur transportation costs.
The production of cement has two stages: the first is the production of clinker, the second is that the clinker is processed into a powder and gypsum or other additives are added to it.
The first stage of the process is the most expensive, it consumes about seventy percent of the cost of cement preparation, because at this stage the main raw materials are extracted. Upper part The limestone mountain is pulled down, and as a result, the limestone layer is exposed. It occurs four to five times at a depth of ten meters (no more), each such layer reaches a thickness of seventy centimeters.
The extracted limestone is crushed so that the largest piece does not exceed ten centimeters in circumference. Then the material is dried, ground again and mixed with other components (such as active mineral additives). Then the resulting mixture is fired. The clinker is ready.
The second stage also consists of many operations: crush the clinker, dry the mineral additives, crush the gypsum, mix the clinker along with the other components. Raw materials will not always be the same in composition and texture. Each type of raw material implies its own production method. There are three methods used in the production of cement: dry, wet and mixed. Each method has its own unique technologies and equipment, and each has its pros and cons.
With the dry production method, the raw materials are pre-dried before grinding, and after grinding they are obtained in the form of a powder (charge). The wet method is used when making cement from chalk, clay using various additives containing iron (carbonate component, silicate component, converter sludge, etc.). The moisture in clay should not be more than twenty percent, and in chalk more than twenty-nine percent. This method is called wet because the mixture is ground in water, resulting in an aqueous suspension, in other words, sludge. Next, it is fired in a kiln, releasing carbon dioxide, then the clinkers in the form of balls are processed into the finest powder - this is cement.
At mixed method both of the previous ones are involved. This method has two types. In the first, the raw materials are prepared with water - in a wet way, obtaining sludge, then the moisture is removed with filters to fifteen to eighteen percent and fired in ovens in the form of an almost dry mass. In the second method, dry raw materials are used, gradually diluted with water and turned into granules ranging in size from ten to fifteen millimeters and fired.
In each of the listed methods, it is very important to maintain proportions, special equipment and a clear sequence of actions. Ready bulk or packaged cement in bags weighing fifty kilograms is loaded onto road or rail transport and sent to its destination.
Not a single construction project can be completed without such an important building material as cement, which indicates its high performance characteristics.

What is cement made from: types and varieties of mixture + manufacturing process + necessary equipment+ how clinker cement is made.

Business can be built in the most different areas, but it is the construction industry that is fundamental for humanity, because even primitive people were engaged in the search for shelter and housing.

Today, the path has already been passed from primitive caves to modern skyscrapers or comfortable mansions. All this became possible thanks to the invention of cement, for which there is always a demand.

What is cement made from? We will answer in the article.

Cement Business: Basics

Cement is a binding substance that is used in construction. The binder has the property of almost tightly fixing the elements caught in it under the influence of water and air.

When dry, it creates a monolithic surface, which is very important in the construction of modern buildings. In addition, it is resistant to temperature changes and most other climatic factors, and most importantly, when frozen it is not harmful to health.

Since it is always necessary to build or patch holes in walls, regardless of the economic situation in the country, the demand for this product is high, and Consumables– cheap.

Therefore, the profitability of the business model of enterprises that make cement is always high. Isn't this an entrepreneur's dream: low costs with stable income?

But there are also disadvantages, the most important of which is the relatively high starting capital, which is needed to launch full-fledged cement production.

The next limiting factor for investment in this area is strict quality control: Do not forget that the safety of buildings depends on this. If a high-rise building collapses because of your cement, then who will be in demand?

But all these problems do not stop us, which means all this is quite feasible.

Types and types of materials from which cement is made

Today, the basic component of cement is clinker, but another 15% comes from mineral mixture, as required by GOSTs.

By the way, if you increase the share of industrial chemicals in the mixture to 20%, then it will already be “pozzolanic cement,” for which there are separate standards.

Thus, GOST 10178-76 regulates the production pure composition, and GOST 21-9-74 – mixtures with various chemical additives.

In general, all the properties of cement can be combined into 7 points, which allow you to customize production for different clients - from a farmer who needs to fill a hole in a barn, to a large construction company from Moscow City:

In addition, cement is separated depending on what it is made from and how it is used:

№	Type	Brief description of properties; what is cement made from?
1.	Lime	Standard cement without additives.
2.	Marly	A mixture based on marly rocks.
3.	Clay with additions of slag and bauxite	Slag and bauxite make cement waterproof, fire- and frost-resistant.
4.	Portland cement and Portland slag cement	A mixture with carbonate or slag additives, as well as with alumina residues. The peculiarity is that it is processed at a temperature of 1500 degrees. When dried, it turns into a strong stone mass, which is actively used in the construction of large buildings and monuments.
5.	Backfilling	A mixture with improved air tightness characteristics. This cement is made for the needs of gas production and other industries that require high-quality insulation.
6.	Hydraulic	High pressure mixture.
7.	Straining	Quick drying mixture.
8.	Sulfate resistant	Slow-drying mixture with increased frost protection.
9.	Decorative	The mixture is made for decorative purposes, therefore it has White color due to a large percentage of gypsum.

How is cement made?

We figured out what cement is made from, now a little about the technologies for its production.

Modern technology includes several stages and elements, forming a vertically integrated structure - from rock mining to the sale of cement mixture or clinker on the wholesale market.

Cement production in industrial scale begins with the demolition of an entire mountain, so a small business is unlikely to be able to do this.

This will require expensive mining equipment, as well as an entire factory workshop with complex equipment, therefore the initial investment can exceed 500,000,000 rubles, and taking into account inflation and exchange rate fluctuations - up to 1 billion.

Or a closed joint stock company, with all the permitting documentation (especially regarding the environment).

At the first stage of production, a mountain is demolished or a deep pit is made to access the “mainland” - under the layer of soil and chernozems there are clays and limestones, which are needed for these purposes. The pit is made about 10 m deep.

Equipment used to make cement:

After this, the limestone and clay are transported by dump trucks to the plant, where they are crushed into a powder.

Then the mixture is fired at a temperature of 1500 degrees, resulting in granulated clinker - the base from which cement is made. Some manufacturers also sell the clinker itself to smaller companies.

To obtain clinker, you will need the maximum of all costs, since you will have to purchase limestone and clay or purchase dump trucks, excavators, etc.

Plus, we need crushers that operate in three stages - from crushing large stones until the mixture turns into powder. A special industrial oven will also be required. It's all connected by a conveyor belt.

According to market players, clinker production accounts for over 70% of the cost of the finished product. To pay for itself, you need to produce about 800 tons of the mixture per day or 176,000 tons per year.

How is cement made from clinker?

The finished mixture is made from clinker, gypsum, sand and mineral additions. After grinding and roasting, large lumps are crushed to a granule size of 1 - 100 microns, as required by GOST standards.

In this case, the technology requires alternate crushing of individual components before mixing. So, for example, first of all, the hardened clinker is crushed, then crushed gypsum is added, and only then a cement mixture is made, adding industrial chemicals. Then comes drying and final grinding.

If you intend to sell a dry product, then the next step is packaging in bags. If you intend to sell it in finished form, then before loading it onto cement trucks, water and other liquid chemicals are added to the mixture, which prevent premature hardening inside the car.

It is important to understand that if you decide to build your own cement manufacturing enterprise without intermediaries, and sell finished product with higher added value, that is, it makes sense to complete this process.

To do this, you need to purchase another furnace and crushers, a cooler, and a dosing unit.

Plus, you need to immediately decide how you will send the cement to the market. Large construction companies make their choice in favor of cement trucks, where they transport a ready-made liquid mixture - with sand and other chemicals (if necessary), so that it can be used in work right away.

Small firms and retail chains They give priority to packages with dry mixture, which are made in several versions - from small bags of up to 5 kg, to bags of 40 kilograms or more. use disposable paper ones.

If you choose this dry method, you will need special equipment for packaging and sorting cement, as well as a warehouse.

Having dealt with the what is cement made from?, you can safely take on its production at your own enterprise.

Do you want to know how and what cement is made from?

The entire technological process in one video:

The situation during the crisis is not easy, but people will still build, which means there will be demand for cement.

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At all times, people have been engaged in construction for their needs, starting with ancient buildings and ending with modern technical masterpieces. In order for buildings and other structures to remain reliable, a substance is needed that will prevent the component parts from disintegrating individually.

Cement is a material that serves to bind building elements together. Its application is great in modern world. It is used in various fields human activity, and the future fate of all structures depends on it.

History of origin

They began to use it in ancient times. At first it was unfired clay. Due to its ease of production and prevalence, it was used everywhere. But due to its weak viscosity and stability, clay has given way to heat-treated materials.

The first high-quality building materials were obtained in Egypt. These are lime and gypsum. They had the ability to harden in air, which is why they were widely used. These building materials met the requirements until navigation began to develop. A new substance became necessary that would resist the action of water.

In the 18th century, a material was invented - romancement. This is a product that could harden both in water and in air. But the increased development of industry required more quality materials and astringent properties. In the 19th century, a new binding agent was invented. It was called Portland cement. This material is still used today. With the development of mankind, new demands are placed on binders. Each industry uses its own brand that has the necessary properties.

Compound

Cement is the main component of the construction industry. The main components in it are clay and limestone. They are mixed with each other and subjected to heat treatment. Then the resulting mass is ground to a powder state. The gray fine mixture is cement. If you mix it with water, the mass will become like a stone over time. Main feature is the ability to harden in air and resist moisture.

Preparation of cement mortar

So that the building mass is required quality, the composition must contain at least 25% liquid. Changing the ratio in any direction leads to a decrease operational properties solution, as well as its quality. Setting occurs 60 minutes after adding water, and after 12 hours the mixture loses its elasticity. It all depends on the air temperature. The higher it is, the faster the mass will harden.

To obtain the solution, sand is needed, to which cement is added. The resulting mixture is thoroughly mixed and filled with water. Depending on the work performed, the solution can be ordinary or enriched. The first consists of proportions 1:5, and the second - 1:2.

Types and production of cement

On this moment Many types of binder material are manufactured. Each has its own degree of hardness, which is indicated in the brand.

The main types include:

• Portland cement (silicate). This is the founder of all types. Every brand uses it as a foundation. The difference is the amount and composition of additives that give cement necessary properties. The powder itself is gray-green in color. When liquid is added, it hardens and becomes stronger. It is not used separately in construction, but is used as a basis for creating
• The plasticized composition reduces costs, has the ability to reduce the mobility of the solution and has excellent resistance to the effects of cold.
• Slag cement. This is the result of clinker crushing and the addition of active additives. Used in construction for the preparation of mortars and concrete.

• Aluminous. It has high activity, speed of setting (45 minutes) and hardening (complete occurs after 10 hours). Also a distinctive property is increased resistance to moisture.
• Acid resistant. Formed by mixing quartz sand and sodium fluoride. To prepare the solution, sodium is added. The advantage of such cement is its resistance to acids. Disadvantage: short service life.
• Color. Formed by mixing Portland cement and pigment substances. The unusual color is used for decorative work.

Cement production consists of 4 stages:

• Extraction of raw materials and their preparation.
• Firing and production of clinker.
• Grind to a powder.
• Addition of necessary impurities.

Cement production methods

There are 3 methods that depend on the preparation of raw materials for heat treatment:

• Wet. With this method, at all stages of cement production there is required amount liquids. Used in situations where the main components cannot participate in technological process without using water. This is chalk with a high moisture content, plastic clay or limestone.

• Dry. All stages of cement production take place with materials containing minimal amount water.
• Combined. Cement production includes both wet and dry methods. The initial cement mixture is made with water, and then it is filtered as much as possible using special equipment.

Concrete

This is a building material that is formed by mixing cement, filler, liquid and necessary additives. In other words, it is a hardened mixture that includes crushed stone, sand, water and cement. Concrete is different from mortar its composition and size of the filler.

Classification

Depending on what binding material is used, concrete can be:

• Cement. The most common type in construction. The basis is Portland cement, as well as its varieties.
• Plaster. Has increased strength. Used as a binding material
• Polymeric. They are based on Suitable for working on horizontal and vertical surfaces. It is an excellent material for finishing and landscaping work.
• Silicate. The binding material is lime and siliceous substances. Its properties are very similar to cement and are used in the production of reinforced concrete structures.

Depending on the purpose, concrete can be:

• Ordinary. Used in industrial and civil construction.
• Special. Found its application in hydraulic structures, as well as for road, insulation and decorative work.
• Special purpose. resistant to chemical, thermal and other specific influences.

Cost of cement

Manufacturers produce products packaged by weight. The weight of cement bags is 35, 42, 26, and 50 kg. It is most profitable to buy the latter option. It is most suitable for loading and allows you to save on packaging. Depending on the object where the work will be carried out renovation work, cement is used various brands, having his own intrinsic value. Each bag of cement is taken into account when paying. Its price is fixed and may fluctuate depending on the requirements of the seller.

Before you start calculating cash costs, you need to decide on one more nuance. Sometimes you can see an advertisement that indicates a price lower than the standard one. You shouldn't fall into such a trap. In such cases, expensive cement is diluted with cheaper cement. By winning a few rubles, you will lose the quality of the building material.

Let's take one 50 kilogram bag of cement. The price of the M400D0 brand will be 220 rubles. The cost of others may vary, but on average it is:

• M400D20 - 240 rubles.
• M500D0 - 280 rubles.
• M500D20 - 240 rubles.

If you only need to use a couple of bags of cement, then it is most profitable to buy them at your local building materials store. And if necessary a large number of, then you should contact the manufacturer.

Cement consumption

Before performing any construction work the question arises of how much cement is needed and what consistency the solution should be. Ideally, strength should be maintained and the proportionality of the components should not be exceeded.

When important and serious work lies ahead, mixing cement and sand “by eye” is unacceptable. If you don't regret it binder material, then with large volumes it will cost huge amounts of money.

So how much cement is needed for the work being done? Construction standards (SNiP) will help you answer. All reasons influencing the production of the mixture are taken into account here. Focusing on the brand of the composition and taking into account all the factors, you can clearly find out the rate of cement consumption per 1 cubic meter solution.

The main feature that many developers do not take into account is that the cement is distributed in the voids between the sand particles. Remember that the composition is active. If stored indoors for a long time, the 500 brand will become 400 in a few months. Therefore, when purchasing, you should always ask for a certificate with the date of issue.

– the basis of any building structure. Almost every building around us, one way or another, was erected using cement mortar. Construction material, created on the basis of cement, can withstand multi-ton loads for decades, practically without experiencing negative influence from outside. Why has cement been the most popular building material for many decades? The editors of the site will try to reveal the same secret formula, thanks to which we will finally find out what exactly cement is made from and why it is considered one of the most durable materials worldwide.

Read in the article

Regulations

Cement, like any other product, must undergo a certification procedure. There are several GOSTs and SNiPs, which to one degree or another relate to the quality of the cement mixture. We list the main ones:

1. GOST 31108-2003 “General construction cements. Technical conditions".
2. GOST 30515-97 “Cements. General technical conditions".
3. GOST 10178-85 “Portland cement and Portland slag cement. Technical conditions".

Chemical composition of cement

Cement itself is nothing more than powder. It is created on the basis of clinker. The composition may contain various components and fillers.

Interesting fact! When cement mortar hardens, its density is not inferior to the density of stone. For creating artificial stone Cement is also used.

Heating occurs up to +1450°C. The structure of natural components changes, and a new substance is obtained - clinker. After this, the resulting substance is combined with gypsum and ground, resulting in the familiar cement powder.

A comment

“This is what the chemical composition of the finished cement powder looks like: 67% calcium oxide (CaO), 22% silicon dioxide (SiO2), 5% aluminum oxide (Al2O3), 3% iron oxide (Fe2O3), 3% other components.

Main characteristics

For cement main technical characteristics his brand remains, it is this marking that will tell about such important characteristic, as an indicator of the maximum load in kg.

The numbers indicate the maximum value that hardened cement can withstand. It is also called the compressive strength index. In practice, this value indicates the weight that the material can withstand without collapsing. For example, when using M200 cement, the load that 1 cm³ can withstand is 200 kg.

Interestingly, it is allowed to test cement only after complete drying, and this happens after 28 days and not earlier. After this, a test sample of cement is placed under a press and compressed. The pressure at which it began to collapse is its mark. Moreover, the procedure is repeated six times, and then the arithmetic mean is calculated from the 4 best indicators. This indicator is measured in MPa and kg/cm².

A comment

Team leader of the repair and construction company "Dom Premium"

“The letter “D” indicates data on special additives used in cement. For example, D10 indicates that 10% additives were added to the dry mixture. Thanks to them, it is possible to give finished design additional strength and frost resistance.

Types of cement by area of ​​use

As we noted earlier, the quality of the cement mixture is affected by various additives. Its scope of application and strength depend on this. For example, frost-resistant samples are used in buildings in areas with harsh climates; in seismically hazardous areas, additives are used that increase the adhesiveness of the mixture. They, in turn, do not give concrete structures crack.

Interesting fact! During the freezing process, the water contained in the concrete expands and begins to destroy it from the inside. However modern technologies make it possible to improve the degree of frost resistance; mineral additives are added to the cement powder, for example, neutralized wood pitch. They create a strong shell around water particles.

Most often, various additives are added to the cement mixture, the percentage of which can reach 10 and 20%. For the construction of monolithic buildings I use M500 grade cement. This material has a higher hardening rate and strength. Typically, it is from this cement mixture that load-bearing structures are built.

What is cement made from?

Typically, cement production plants are built where there are deposits of limestone and other rocks that are used to create clinker. The main natural elements from which cement is made are:

• carbonate type fossils: crystalline rocks that can be fired;
• clay materials, as well as rocks sedimentary nature of mineral origin. The raw material is characterized by viscosity and is used in the dry production method.

A comment

Team leader of the repair and construction company "Dom Premium"

“When choosing cement, pay attention to such an indicator as the fineness of grinding. The finer the structure of the powder, the stronger the mixture will be.

Carbonate rocks

What carbonate rocks are used in cement production:

• chalk(limestone variation) - easy to process, cheap and versatile;
• marl, or marly limestone. The advantage of these rocks is that they contain sufficient quantity moisture, in addition, they contain the necessary particles of clay;
• limestone raw materials, shell rocks characterized by the absence of silicon inclusions. The rock has a porous structure and is easily destroyed under the influence of compressive forces;
• carbonate rocks. They are characterized by valuable physical properties.

Clay raw materials

Clay rocks include:

• clay, containing mineral inclusions that swell when water is added;
• loams− diluted with sand fraction;
• slates– strong clayey rocks;
• loess– inelastic porous rock with quartz inclusions.

Corrective additives

In addition to mineral raw materials, special plasticizers are used in the production of cement. The most commonly used additives are mineral-based additives containing fluorspar, as well as apatites.

Important! The basis of any binder is cement clinker and only 15-20% mineral additives. The strength of the future cement and its other characteristics depend on it.

How cement is made in production

Like any production, the creation of a cement mixture occurs strictly according to a special technological scheme. And consists of the following stages:

1. Making clinker. Let us remember that it is made from limestone and clay in a percentage ratio of 75×25. The mixture is placed in an oven, at a temperature of approximately +1500°C the composition changes. A viscous substance is formed that reliably holds all the clinker granules together. The resulting clinker is cooled in special refrigeration units.
2. Then the granules are further crushed. Grinding occurs in special grinding mills. They are drums with steel balls placed there.
3. Fine grain and mineral additives are also added to the crushed clinker.

Exist different technologies preparation of raw materials. Let's look at the main ones.

Wet method

Wet technology requires the mandatory addition of water at the grinding stage; in this case, chalk is used instead of lime. This creates a special mixture, or charge, which is then re-dried in the oven, turning into a kind of glass ball, which is then crushed again. At the same time, the cost of cement increases significantly. Do you think that the mixture prepared in this way is more durable.

Dry method

Dry method – more cheap option. In this case, in practice, two technological operations are combined - grinding and drying the mixture. Hot gases are sent to the ball mill, which carry out drying. Here the output is a ready-made powder.

Combined techniques

The combined option combines the features of the wet and dry methods. Technologies differ in every enterprise. Sometimes instead wet method, which allows clinker to be moistened up to 50%, options are used with a decrease in humidity at this stage to 18 or 20%. The second method involves the preparation of a dry mixture, followed by humidification to 14%, granulation, and final annealing. It all depends on the tasks facing the technologist.

How to make cement at home

Despite the apparent complexity of cement production, it is possible to make it yourself at home. It is clear that this option will not be as technologically advanced as at the factory, and it will also not be possible to burn it at the required temperature. However, we can tell you some tricks. Let's consider one of the popular recipes for creating a composition that is quite suitable for sealing cracks and. To create the mixture we need water-based lime, stone ash and plain water.

Today it is impossible to imagine the construction of any object without the use of cement. It is used at all stages construction process. Without it, it is impossible to complete the foundation, laying walls, as well as internal and external finishing. To date, no analogues of this building material have been invented, which indicates unique properties cement. Do you know what cement consists of?

What is cement

Cement is a building material, which is presented in the form of crushed powder obtained from clinker. Its composition may contain modifying components and fillers.

According to GOST

The process of obtaining general construction cements must be carried out taking into account the requirements of GOST 31108-2003. It is the standard that is able to regulate proportions necessary ingredients, included in the composition of the dry mass and the production technology of the material. But this standard does not include special-purpose material.

About what specific gravity cement grade M 500 is described in this

Definition of species

Today, the definition of the most common materials includes:

• aluminous;
• lime-ash;
• waterproof.

Aluminous

The process of obtaining such material is carried out using the melting method when exposed to temperatures of 1380 - 1600 degrees. In this case, there is no need to use fine grinding of the charge. The process of obtaining this type of material is carried out in furnaces different types. The most commonly used are blast furnace and electric.

The composition of this material involves the following components:

1. Aluminium oxide.
2. Calcium oxide.
3. Silicon oxide.
4. Iron oxide.

How to use dry cement sand mixture M 150 described

In addition, the composition of aluminous cement is rich in dicalcium silicate. It allows for delayed curing. To increase certain properties, the composition can be supplemented with aluminates and ballast admixtures. This mixture will allow you to obtain a reliable and durable structure.

Airtight

This cement contains finely ground blast furnace slag and gypsum stone in a 2:1 ratio. A structure laid out on the basis of such material acquires the necessary hardness in water and air. If hardening was carried out in water, then the percentage of shrinkage is minimal.

The setting process occurs after 10 minutes, and for complete drying you need to wait 3 days. The resulting solutions based on airtight material are characterized by such properties as waterproofness, fire resistance, durability, and stability. Compared to Portland cement, this material has any fire resistance rating. In addition, the hardening process occurs faster than that of aluminous.

What is the bulk density of cement M 500 described

Lime-ash

To obtain this composition, components such as fuel ash and slag with lime are used. After mixing these elements, they are finely ground. To improve the properties of lime-ash cement, add 5 g of gypsum. It allows for rapid hardening and increases the strength of the structure.

When constructing a structure for a specific purpose, it is necessary to purchase the required brand of cement, which would contain all the necessary components. If all proportions are strictly observed by the manufacturer, then the resulting product will have excellent strength, durability and resistance to various aggressive environments. Read about what this is in our article.