Magnesium binders. Liquid glass and acid-resistant cement

A mortar prepared from cement in a concrete mixer is loaded into a wheelbarrow.
Cement

(Latin caementum - “crushed stone, broken stone”) - an artificial inorganic hydraulic binder. One of the main building materials. When interacting with water, aqueous solutions of salts and other liquids, it forms a plastic mass, which then hardens and turns into a stone-like body. Mainly used for making concrete and mortars. Cement is a hydraulic binder and has the ability to gain strength in wet conditions, which is fundamentally different from some other mineral binders (gypsum, airborne lime), which harden only in air.

Cement grade is a conditional value that means that the compressive strength will not be lower than the designated grade (200, 300, 400, 500, 600)

Cement for mortars

- low-clinker composite cement intended for masonry and plaster mortars. They are made by grinding together Portland cement clinker, active mineral additives and fillers.

Historical information

Mixing
The Romans mixed certain materials into lime to give it hydraulic properties. These were:

pozzolans (volcanic ash deposits from Vesuvius);
crushed or crushed bricks;
tracks they found in the Eifel area (hardened deposits of volcanic ash).

Despite the differences, all these materials contain oxides: silicon dioxide SiO2 (quartz or silicic acid), aluminum oxide Al2O3 (alumina), iron oxide Fe2O3 - and cause lime to interact with them; in this case, water is added (hydration) with the formation, first of all, of compounds with silica. As a result, insoluble calcium hydrosilicates crystallize. In the Middle Ages, it was accidentally discovered that the products of firing limestone contaminated with clay were not inferior to Roman pozzolanic mixtures in water resistance and even surpassed them.

Mortar mixer for underground concrete work

After this, a century-long period of intense experimentation began. At the same time, the main attention was paid to the development of special deposits of limestone and clay, to the optimal ratio of these components and the addition of new ones. Only after 1844 did they come to the conclusion that, in addition to the exact ratio of the components of the raw mixture, a high firing temperature (about +1450 ° C, 1700 K) was first of all necessary to achieve a strong connection of lime with oxides. These three oxides, after sintering with lime, determine the hydraulic properties; they are called oxides that cause hydraulicity (hydraulicity factors).

Portland cement is obtained by heating limestone and clay or other materials of similar gross composition and sufficient activity to a temperature of +1450...+1480 °C. Partial melting occurs and clinker granules are formed. To obtain cement, clinker is ground together with approximately 5% gypsum stone. The gypsum stone controls the rate of setting; it can be partially replaced by other forms of calcium sulfate. Some specifications allow the addition of other materials during grinding. A typical clinker has an approximate composition of 67% CaO, 22% SiO2, 5% Al2O3, 3% Fe2O3, 3% other components and usually contains four main phases called alite

,
belite
,
aluminate phase and aluminoferrite phase
. Several other phases, such as alkali sulfates and calcium oxide, are usually present in clinker in small quantities.

Alite is the most important constituent of all conventional cement clinkers; its content is 50-70%. This is tricalcium silicate, Ca3SiO5, the composition and structure of which is modified due to the placement of foreign ions in the lattice, especially Mg2+, Al3+ and Fe3+. Alite reacts relatively quickly with water and in normal cements, of all phases, plays the most important role in the development of strength; for 28-day strength, the contribution of this phase is especially important.

The belite content for normal cement clinkers is 15–30%. It is a dicalcium silicate Ca2SiO4, modified by the introduction of foreign ions into the structure and usually completely or mostly present in the form of a β-modification. Belite reacts slowly with water, thus having little effect on strength during the first 28 days, but significantly increases strength in later periods. After a year, the strengths of pure alite and pure belite under comparable conditions are approximately the same.

The aluminate phase content is 5-10% for most normal cement clinkers. This is tricalcium aluminate, abbreviated as 3CaAS (composition - 3CaO*Al2O3*SiO2), significantly changed in composition, and sometimes in structure, due to foreign ions, especially Si4+, Fe3+, Na+ and K+. The aluminate phase reacts rapidly with water and can cause undesirably rapid setting unless a setting control agent, usually gypsum, is added.

The ferrite phase makes up 5-15% of ordinary cement clinker. This is tetracalcium aluminoferrite, abbr. 4СaAFS (4CaO*Al2O3*Fe2O3*SiO2), the composition of which changes significantly when the Al/Fe ratio changes and the placement of foreign ions in the structure. The rate at which the ferrite phase reacts with water may vary somewhat due to differences in composition or other characteristics, but is generally high early on and intermediate between the rates of alite and belite later in life.

The outstanding scientific chemist Alexey Romanovich Shulyachenko is considered the father of the Russian cement industry. The Antonov shaft kiln is widely used for firing and clinker production. Yu. M. Butt, S. M. Royak, I. F. Ponomarev, N. A. Toropov and others carried out a lot of work on issues of cement technology and hardening of hydraulic binders.

Everything you wanted to know about cement

Cement is a powdered construction binder material that has hydraulic properties.

Cement consists of clinker and, if necessary, gypsum or its derivatives and additives. When interacting with water or other liquids, cement forms a plastic mass (cement paste), which, when hardened, turns into a stone-like body.

Cements include a large group of hydraulic binders, the main components of which are silicates and calcium aluminates, formed as a result of firing before sintering the raw material mixture of the proper composition.

HISTORY OF CEMENT

Approximately 3000-4000 BC. methods were found for producing artificial binders by firing certain rocks and finely grinding the products of this firing. The first artificial binders - building gypsum, and then lime - were used in the construction of unique structures: the concrete gallery of the legendary labyrinth in ancient Egypt (3600 BC), the foundations of the oldest structures in Mexico, the Great Wall of China, the Roman Pantheon. Clay, gypsum and lime can harden and serve only in air, which is why these binding materials are called air binders. All air binders are characterized by relatively low strength. Over time, they learned to increase the water resistance of lime mortars by introducing into them finely ground baked clay, broken bricks or volcanic rocks, known as “pozzolans”. That's what the ancient Romans called them after the deposits near the city of Pozzuolli. On the territory of the once existing Rus', the development of the production of binding materials is associated with the emergence of ancient cities - Kyiv, Novgorod, Moscow, etc. Cementing materials were used in the construction of fortress walls, towers, cathedrals. In 1584, the “Stone Order” was established in Moscow, which, along with the procurement of building stone and the production of bricks, was also in charge of the production of lime. For several thousand years, gypsum and air-lime were the only binding materials. However, they were characterized by insufficient water resistance. Development of navigation in the XVII-XVIII centuries. required the creation of new binders that are resistant to water for the construction of port facilities. In 1756, the Englishman D. Smith, by firing limestone with clay impurities, obtained a water-resistant binder called hydraulic lime. In 1796, the Englishman D. Parker patented a novel cement capable of hardening both in air and in water. In our time, these binders have lost their practical significance, but until the second half of the 19th century. they were the main materials for the construction of hydraulic structures. The intensive development of industry in Russia in the 18th century, when 3 thousand industrial enterprises were built, not counting mining plants, required the systematization of the accumulated experience in the production and use of binders, and the creation of more efficient types of them. In 1807, academician V.M. Severgin gave a description of the binder obtained by firing marl and then grinding it. The resulting product was better in quality than Roman cement.

In Russia

Cement began to be produced in the last century. In the early 20s of the XIX century. E. Deliev obtained a calcining binder from a mixture of lime and clay and published the results of his work in a book published in Moscow in 1825. In 1856, the first Portland cement plant in Russia was launched, which was located in the city of Grozdets, then factories were built in Riga (1866), Shchurov (1870), Punan-Kunda (1871), Podolsk (1874), Novorossiysk (1882), etc. At the beginning of the 20th century, there were 60 cement factories in Russia with a total capacity of about 1.6 million tons of cement. However, after the First World War, most of the cement factories were destroyed. With the advent of Soviet power, Russia's cement industry had to be created practically from scratch. Already in 1962, the USSR took first place in the world in cement production. In 1971, cement production in the country exceeded 100 million tons. The cement industry of the USSR was distinguished by its highly concentrated production. The average capacity of a cement plant in the USSR was almost 2 times higher than in the USA, and 30% higher than in Japan. Today Russia ranks fifth in the world in terms of cement production, behind China, India, the USA and Japan. The Russian cement industry is among the fastest growing global industries with a growth rate of about 9%, and an increase in growth rates can be predicted in the coming years. The main disadvantage of Russian cement plants today is that they use the wet method of cement production, which is much more energy-intensive than the dry method used in developed countries. Therefore, it is important for companies to gradually switch to more advanced energy-saving technologies.

TYPES OF CEMENTS

White cement (BC)

made from low-iron clinker (the gray color of ordinary cement is mainly due to the presence of iron compounds in the original raw materials).
White cement is a material with unique characteristics that allow it to be used in the manufacture of sculptural elements, columns, as well as for finishing work, for example, the facade of a building. The aesthetic requirements for facades and other formal building elements make the use of white cement especially effective. White cement is also used for colored cement concrete road surfaces, for example in areas near monumental buildings. Waterproof Expanding Cement (WEC)
is a fast-setting, fast-hardening hydraulic binder produced by co-grinding and thoroughly mixing ground aluminous cement, gypsum and highly basic calcium hydroaluminate.
The cement is characterized by rapid setting: the beginning of the process is earlier than 4 minutes, the end no later than 10 minutes. from the moment of confinement. The linear expansion of cement paste samples hardening in water for 1 day should be in the range of 0.3-1%. VRC is used for caulking and waterproofing seams of tubings, socket joints for creating waterproofing coatings, sealing joints and cracks in reinforced concrete structures, etc. Waterproof non-shrink cement (WBC)
is a fast-setting and fast-hardening hydraulic binder produced by thoroughly mixing aluminous cement, semi-hydrous gypsum and slaked lime.
The beginning of setting is no earlier than 1 minute, and the end no later than 5 minutes. from the moment of closure. Cement is used to construct a waterproofing shotcrete shell for concrete and reinforced concrete structures operated in conditions of high humidity (tunnels, foundations, etc.). Hydrophobic cement (HFC)
is obtained by finely grinding Portland cement clinker together with gypsum and a water-repellent additive (asidol, soaponaft, oleic acid, oxidized petrolatum, vat residues of synthetic fatty acids, etc.).
This cement has less water absorption, greater frost resistance and water resistance than ordinary Portland cement; Can be stored for a long time even in a humid environment without loss of activity. Increased air entrainment of this cement reduces the strength of heavy concrete, however, in the production of light and cellular concrete this property plays a positive role. Concrete mixtures made with hydrophobic cement undergo less delamination and are resistant to alternating wetting and drying. Alumina cement (ACC)
is a fast-hardening hydraulic binder obtained by finely grinding a raw material mixture rich in alumina, calcined before sintering or fusion.
Limestone or lime and rocks with a high Al2O3 alumina content, such as bauxite, are used as raw materials for the production of aluminous cement. The mineralogical composition of aluminous cement is characterized by a high content of low-basic calcium aluminates, the main of which is single-calcium aluminate CaO&Al2O3. The use of aluminous cement is limited by its high cost. It is used for urgent repair and emergency work, for work in winter conditions, for concrete and reinforced concrete structures exposed to highly mineralized waters, for the production of heat-resistant concrete, as well as for the production of expanding and non-shrinking cements. Magnesia cement (MGC)
is used for constructing magnesia floors as a magnesia binder, which is a fine powder, the active part of which is magnesium oxide.
Magnesium oxide, in turn, is a product of moderate firing of natural carbonate rocks of magnesite or dolomite. Portland cement
and its varieties are the main binders in construction.
Portland cement is a hydraulic binder obtained by finely grinding Portland cement clinker with gypsum, as well as special additives. Portal cement clinker is a product of firing a finely dispersed homogeneous raw material mixture consisting of limestone and clay or some materials (marl, blast furnace slag, etc.) before sintering. During firing, a predominant content of highly basic calcium silicates in the clinker is ensured. To regulate the setting time of Portland cement, gypsum dihydrate is added to the clinker during grinding in an amount of 1.5-3.5% (by weight of cement in terms of SO3). Based on their composition, they are divided into: Portland cement without additives; Portland cement with mineral additives; slag Portland cement and others. Sulfate-resistant cement
is made from clinker of a standardized mineralogical composition: clinker should contain no more than 5% tricalcium aluminate and no more than 50% tricalcium silicate.
A low limiting content of tricalcium aluminate is required because sulfate corrosion develops as a result of the interaction of sulfates in the environment with tricalcium hydroaluminate of cement stone. If C3A is present in small quantities in cement stone, then a small amount of calcium hydrosulfoaluminate is formed. Then it is not dangerous, since it is distributed in the pores of the concrete, displacing water or air from there, and does not cause internal stresses in the concrete. Sulfate-resistant cement is usually produced in two grades: 300 and 400. Well cement
is a type of Portland cement intended for cementing oil and gas wells.
Well cement is produced by joint fine grinding of clinker and gypsum. In Russia, two types of well cement are produced: for so-called cold (with temperatures up to -40°C) and hot (up to +75°C) wells. Well cement is used in the form of cement paste containing 40-50% water. Slag cement
is the general name for cements obtained by co-grinding granulated blast furnace slag with activating additives (lime, building gypsum, anhydrite and others) or by mixing these separately crushed components.
There are the following types of slag Portland cement: lime-slag with a lime content of 10-30% and gypsum up to 5% by weight of cement and sulfate-slag with a gypsum or anhydrite content of 15-20%, Portland cement up to 5% or lime up to 2%. Slag cement is used to produce mortars and concretes, used mainly in underground and underwater structures. Lime-slag cement is most effective in the production of autoclave materials and products. Colored cement
is produced from white Portland cement clinker by co-grinding with pigments of various colors, for example, ocher, red lead, chromium oxide. It is also possible to obtain colored cements by mixing white cement with pigments. The use of colored cements, which contributes to the architectural and decorative design of structures, is of great importance in the industrial finishing of large-element buildings. These cements are also used for colored cement-concrete road surfaces, for example, in areas near monumental structures. In addition to those listed, there are some special types of Portland cement, for example, cement cement, for the production of asbestos-cement products.

CEMENT MARKINGS

Cement, like any other material used in construction, differs in its physical and technical characteristics depending on the conditions under which it is intended to be used. Cement is marked according to two characteristics - the ability to withstand a certain load and the percentage of various additives to the total volume of cement. First parameter

denoted by the letters
M
or
PC
with a number next to it.
The number will indicate the maximum strength properties of cement. M 500
marking indicates that this type of cement can withstand a load of 500 kg/cm.
The most popular are cements marked from 350 to 500, but cements marked 700 are also common. The second parameter
of cement, reflected in its marking, is the percentage of additives.
It is designated by the
letter
D. For example, cement marked D20
will contain 20% additives.
This characteristic is important because the percentage of additives affects the ductility and strength of cement. If cement has any additional specific properties, this is indicated by special designations. As mentioned above, the most popular grades of cement are grades from 350 to 500. Let's consider the main characteristics and application of some of them. Cement grade M (PC) 400 - D20
indicates that this type of cement has increased frost resistance and water resistance.
The main area of application of such cement is construction (this includes both residential and industrial, agricultural). It is used in the manufacture of prefabricated reinforced concrete, wall ceilings, foundations, etc. Cement grade M 500 - D20
; in addition to good water resistance and frost resistance, this type of cement has reduced resistance to corrosive influences.
It is used, like cement grade PC 400 - D20, for construction, and it is also suitable for plastering, masonry and other repair and construction work and the production of various mortars. Cement grade M 500 - D0
, introduced into the composition of concrete, gives the latter such characteristics as: increased frost resistance, water resistance, and durability.
It is indispensable in industrial construction, especially when performing emergency and restoration work. When constructing structures that are in one way or another associated with exposure to fresh or mineralized water, it is necessary to use cement grade PC (M) 400 - D0
. You can’t do without it when making concrete structures using thermal and moisture treatment. This cement is also good for making concrete and mortars. Another important characteristic of cement is its hardening time. This process takes place in several stages: the first is the setting (beginning of hardening) of the cement. It takes 40 - 50 minutes. The second is the end of hardening. It comes in 10 - 12 hours.

You can find our range of cements, their prices and delivery conditions here.

CEMENT PRODUCTION TECHNOLOGIES

Cement production includes two stages: the first is the production of clinker, the second is bringing the clinker to a powdery state with the addition of gypsum or other additives. The first stage is the most expensive, accounting for 70% of the cost of cement. This happens as follows: First stage

is the extraction of raw materials.
The development of limestone deposits is usually carried out by demolition, that is, part of the mountain is “carried down”, thereby revealing a layer of yellowish-green limestone, which is used to make cement. This layer is, as a rule, located at a depth of up to 10 m (up to this depth it occurs four times), and its thickness reaches 0.7 m. Then this material is sent along a conveyor to be crushed into pieces equal to 10 cm in diameter. After this, the limestone is dried, and the process of grinding and mixing it with other components begins. This raw material mixture is then fired. This is how clinker is obtained. The second stage
also consists of several stages. These are: crushing clinker, drying mineral additives, crushing gypsum stone, grinding clinker together with gypsum and active mineral additives. However, it must be taken into account that the raw material is not always the same, and the physical and technical characteristics (such as strength, humidity, etc.) of the raw material are different. Therefore, for each type of raw material, its own production method was developed. In addition, this helps ensure good uniform grinding and complete mixing of the components.

In the cement industry, three production methods are used, which are based on different technological methods for preparing raw materials: wet, dry and combined. Wet production method

used in the production of cement from chalk (carbonate component), clay (silicate component) and iron-containing additives (converter sludge, ferrous product, pyrite cinders).
The moisture content of clay should not exceed 20%, and the moisture content of chalk should not exceed 29%. This method is called wet because the raw material mixture is crushed in an aqueous environment, and the output is a mixture in the form of an aqueous suspension - sludge with a moisture content of 30 - 50%. Next, the sludge enters the roasting furnace, the diameter of which reaches 7 m and the length - 200 m or more. During firing, carbon dioxide is released from the raw material. After this, the clinker balls, which are formed at the outlet of the kiln, are ground into a fine powder, which is cement. The dry method
means that the raw materials are dried before or during the grinding process.
And the raw material mixture comes out in the form of a finely ground dry powder. With the dry method, which, in all likelihood, belongs to the future of cement production, not sludge is supplied to meet the burning gases, but raw materials ground into powder: limestone, clay, slag. This saves fuel, which in the wet method is spent on water evaporation. Combined method
, as the name suggests, involves the use of both dry and wet methods. The combined method has two varieties. The first assumes that the raw material mixture is prepared using a wet method in the form of sludge, then it is dehydrated on filters to a moisture content of 16 - 18% and sent to kilns for firing in the form of a semi-dry mass. The second preparation option is exactly the opposite of the first: first, a dry method is used to prepare the raw material mixture, and then, adding 10 -14% water, it is granulated, the size of the granules is 10 - 15 mm and served for firing.

MAIN CEMENT PLANTS IN RUSSIA

Angarsk Cement Mining Plant

. OJSC "Angarskcement" Website: https://www.sibcem.ru 665809, Irkutsk region, Angarsk, Industrial site, post office box 397

Achinsk cement Website: https://www.baselcement.ru 662150, Krasnoyarsk region, Achinsk, Southern industrial zone, block XII, building 1

Babinovsky Cement Site: https://www.bcf.ru Tosnensky district, Leningrad region

Belgorod cement Website: https://www.eurocem.ru Belgorod, st. Sumskaya, cement plant site

Verkhnebakansky cement Website: https://www.bakanka.ru Krasnodar region, Novorossiysk, Verkhnebakansky village, st. Orlovskaya, 11

Volkhov Cement Site: https://www.metachem.spb.ru 187400, Leningrad region, Volkhov, Kirovsky prospect, 20

Volsky cement Website: https://www.holcim.ru 412902, Saratov region, Volsk, st. Tsementnikov, 1

Vorkuta Cement Komi Republic, Vorkuta, village. Severny-1

Voskresensky cement Website: https://www.lafarge.ru Moscow region, Voskresensk, st. Communes, 4

Gaidukovsky cement Website: https://www.bakanka.ru 353900, Krasnodar region, Novorossiysk, Gaiduk village, st. Zavodskaya, 6

Gornozavodsk Cement Site: https://www.gcz.su Russia, Perm region, Gornozavodsk

Zhigulevsky cement Website: https://www.eurocem.ru Samara region, Zhigulevsk urban district, Zhigulevsk, 1st Promyshlenny proezd, 4

Katav-Ivanovsky cement Website: https://www.eurocem.ru Chelyabinsk region, Katav-Ivanovsk, Tsementnikov st., 1

Korkinsky cement Website: https://www.lafarge.ru 456541, Russia, Chelyabinsk region, Korkino, Pervomaisky village, st. Zavodskaya, 1

Krasnoyarsk cement Website: https://www.sibcem.ru 660019, Krasnoyarsk region, Krasnoyarsk, st. Krasnopresnenskaya, 1

Kuznetsk cement Website: https://www.unicementgroup.com 654005, Russia, Kemerovo region. Novokuznetsk, st. Liza Chaikina, 15

Lipetsk Cement Site: https://www.eurocem.ru Lipetsk, Tsemzavod area

Magnitogorsk cement Website: https://mcoz.mgn.ru Chelyabinsk region, Magnitogorsk, Beloretskoye highway, 11

Maltsovsky Cement Site: https://www.eurocem.ru 242610, Bryansk region, Fokino, st. Tsementnikov, 1

Mikhailovsky Cement Website: https://www.eurocem.ru 391721, Ryazanskaya. region, Mikhailovsky district, village. October

Mordovian cement Website: https://www.mordovcement.ru 431721, Russia, Republic of Mordovia, Chamzinsky district, town. Komsomol

Mokhsogollohsky cement Website: https://www.yakutcement.ru 678020, Republic of Sakha (Yakutia), Khangalassky ulus, village Mokhsogolloh, st. Zavodskaya, 32

Nevyansky cement Website: https://www.eurocem.ru 624173, Sverdlovsk region, Nevyansky district, village. Cementny, st. Lenina, 1

Novorossiysk cement Website: https://www.novoroscement.ru 353902, Russia, Krasnodar region, Novorossiysk, Sukhumskoe highway, no. 60

Novotroitsky cement Website: https://www.novocement.ru Russia, Orenburg region, Novotroitsk, st. Zavodskaya, 3

OJSC Slantsevsky Cement

. HeidelbergCement Rus LLC Website: https://www.heidelbergcement.com/ru/ru/country/about_us/index.htm 188560, Leningrad region, Slantsy, Kingiseppskoe highway, 1

LLC "Tulacement"

. HeidelbergCement Rus LLC Website: https://www.heidelbergcement.com/ru/ru/country/about_us/index.htm 301382, Russia, Tula region, Aleksinsky district, Novogurovsky village, st. Zheleznodorozhnaya, 3

Pikalevo cement Website: https://www.eurocem.ru 187600, Leningrad region, Pikalevo, Straightened highway, no. 1

Podgorensky cement Website: https://www.eurocem.ru 396560, Voronezh region, town. Podgorensky, st. Tsemzavoda village, 14

Podolsk cement Website: https://www.cement.podolsk.ru 142101, Moscow region, Podolsk, st. Pleshcheevskaya, 15

Savinsky Cement Website: https://www.eurocem.ru 164288, Arkhangelsk region, Plesetsk district, Savinsky village

Sebryakovsky cement Website: https://www.sebcement.ru 403342, Russia, Volgograd region, Mikhailovka, st. Industrialnaya, 2

Sengileevsky Cement Site: https://www.seng-cem.narod.ru 433385, Russia, Ulyanovsk region, Sengilei, Cement Plant

Slantsevsky cement Website: https://www.lsrgroup.ru 188561, Leningrad region, Slantsy, st. Lomonosova, 25A

Spassky Cement Site: https://www.parkgroup.ru 692239, Russia, Primorsky Territory, Spassk-Dalniy, st. Cementnaya, 2

Stary Oskol cement Website: https://www.eurocem.ru 309504, Belgorod region, Stary Oskol, South-Western industrial district, industrial zone, Tsemzavodskaya site, passage 1

Teploozersky Cement Site: https://www.parkgroup.ru 679110, Russia, Jewish Autonomous District, Obluchinsky district, Teploozersk village

Timlyuysky cement Website: https://www.sibcem.ru 671205, Republic of Buryatia, Kabansky district, Kamensk village, st. Promyshlennaya, 3

Topkinsky Cement Website: https://www.sibcem.ru/ 652300, Kemerovo region, Topki, Industrial site

Tuapse cement Website: https://www.baselcement.ru 352800, Russia, Kranodar region, Kirpichnoe village

Ulyanovsk cement Website: https://www.eurocem.ru Ulyanovsk region, Novoulyanovsk, Promyshlenny passage, 1

Cherkessk cement Website: https://www.eurocem.ru Karachay-Cherkess Republic, Cherkessk-15, industrial site

Chernorechensky cement Website: https://www.iskitimcement.ru Novosibirsk region, Iskitim, st. Zavodskaya, 1a.

Chiri-Yurt cement plant Russia, Chechen Republic, Shalinsky district, Chiri-Yurt village

Shchurovsky cement Website: https://www.holcim.ru 140414, Russia, Moscow region, Kolomna, st. Tsementnikov, 1

Yuzhno-Sakhalinsk cement 693000, Russia, Sakhalin region, Yuzhno-Sakhalinsk, st. Purkaeva, 53, room 62

South Ural Cement Site: https://www.yugpk.ru 462360, Russia, Orenburg region, Novotroitsk, 5.4 km, west, No. 5

Uchulensky cement Website: https://www.sgmkgroup.ru 652920, Russia, Kemerovo region, Tashtagol district, Temirtau village, st. Central, 12

"Delivery-SM"

Today we have the opportunity to offer you packaged cements produced
by EUROCEMENT group CJSC
,
Mordovcement OJSC
and
Voskresensky Cement Plant OJSC
in 50 kg bags.
You can find prices and delivery conditions here
.

Source: https://www.nsp.su

Types of cement

Based on the presence of the main mineral, cements are divided:[1]

Roman cement - predominance of belite, not currently produced;
Portland cement - predominant alite, most widely used in construction;
aluminous cement - predominance of the aluminate phase;
magnesia cement (Sorel cement) - based on magnesite, mixed with an aqueous solution of salts;
acid-resistant cement - based on sodium hydrosilicate (Na2O m
SiO2
n
H2O), a dry mixture of quartz sand and sodium silicofluoride, sealed with an aqueous solution of liquid glass.

Biocement is also known, which differs from conventional cement in that it is produced using biotechnology.

In the vast majority of cases, cement refers to Portland cement and cements based on Portland cement clinker. At the end of the 20th century, the number of varieties of cement was about 30.[1]

Based on strength, cement is divided into grades, which are determined mainly by the compressive strength of halves of prism samples measuring 40x40x160 mm, made from a 1:3 cement solution with quartz sand. Grades are expressed in numbers M200 - M600 (usually in increments of 100 or 50), indicating compressive strength of 100-600 kg/cm² (10-60 MPa), respectively. Due to its strength, cement with grade 600 is called “military” or “fortification” and costs significantly more than grade 500. It is used for the construction of military facilities, such as bunkers, missile silos, and so on.

Currently, cement is divided into classes based on strength. The main difference between classes and brands is that strength is not derived as an average indicator, but requires at least 95% assurance (that is, 95 samples out of 100 must correspond to the declared class). The class is expressed in numbers 30-60, which indicate compressive strength (in MPa).

Hydraulic binder based on magnesium cement.

The composition of magnesia cement, or Sorel cement, has not undergone significant changes since its creation to the present day. This is explained by the need to maintain a fairly strict ratio in its composition between caustic magnesite and the sealer. When mixed with an aqueous solution of magnesium chloride, the composition contains 62–67% MgO and 33–38% MgCl2 6H2O, and when mixed with a solution of magnesium sulfate, the composition contains 80–84% MgO and 16–20% MgSO4. If you deviate from these ratios, the strength of the products decreases. Other known compositions of magnesia cements, as a rule, contain various types of fillers (diopside, serpentinite, tremolite, etc.) while maintaining a constant ratio between MgO and salt.

Magnesia cements belong to the group of air binders, and their main disadvantages are low water resistance, estimated by the water resistance coefficient in the range of 0.1–0.3 and the need to use freshly fired magnesite to obtain cement stone with a strength of 30–50 MPa at the age of 28 days under air hardening at a relative air humidity of less than 60%. In addition, caustic magnesite must contain at least 85% MgO.

The low water resistance of products made from magnesium cement is explained by the presence of magnesium trihydroxychlorides (3Mg(OH)2·MgCl2·7H2O) or trihydroxysulfates (3Mg(OH)2·MgSO4·8H2O) in the final hydration products of the binder, which can dissolve in water. Therefore, the question naturally arises about the possibility of using a sealer that would be active in relation to MgO and would form hydration products that are insoluble in water and ensure the formation of a structure of products with a strength not inferior to the strength of products made from classical magnesia cement.

We have found the answer to the question posed and it can be solved by using an aqueous solution of magnesium bicarbonate Mg(HCO3)2 as a mixing liquid at the following ratio: caustic magnesite - 60–75%, aqueous solution of Mg(HCO3)2 - 25–40%.

When caustic magnesite interacts with an aqueous solution of Mg(HCO3)2, a hydration reaction first occurs:

MgO + H2O -> Mg(OH)2. (1)

The resulting magnesium hydroxide then reacts with magnesium bicarbonate according to the reaction:

Mg(OH)2 + Mg(HCO3)2 + 2H2O -> MgCO3 Mg(OH)2 3H2O + CO2, (2) with the formation of magnesium hydroxycarbonate hydrate and carbon dioxide, which, when interacting with excess magnesium hydroxide, forms secondary magnesium bicarbonate:

Mg(OH)2 + 2CO2 -> Mg(HCO3)2. (3)

Secondary magnesium bicarbonate again interacts with magnesium hydroxide by reaction (2) to form a new portion of magnesium hydroxycarbonate hydrate, which, together with magnesium hydroxide, forms the primary hydration products of magnesium cement, ensuring its hardening during the recrystallization of primary colloidal products into a crystalline state.

Thus, as a result of sequential and cyclic reactions (1, 2, 3), two main crystalline phases are formed in the cement stone - magnesium hydroxide and magnesium hydroxocarbonate hydrate, the quantitative ratio between which is determined by the content of magnesium bicarbonate in the mixing liquid. The absence of soluble compounds in cement stone made from such a binder [2] determines its increased water resistance with a water resistance coefficient of 1.1–1.4, and such cement stone hardens with increasing strength not only in an air environment with a relative humidity of more than 75%, but also in water after preliminary hardening in air for 3–7 days.

A significant advantage of such a binder is the possibility of using stale caustic magnesite with a content of active magnesium oxide of more than 40%. Stale magnesite powder may contain, in addition to MgO, also Mg(OH)2 and MgCO3, formed by the interaction of MgO with moisture and carbon dioxide in the air. Impurities of Mg(OH)2 and MgCO3 do not reduce the activity of the interaction of stale magnesite powder with a solution of magnesium bicarbonate, since the interaction of Mg(OH)2 with Mg(HCO3)2 proceeds according to reaction (2, 3), and MgCO3 interacts with carbon dioxide, formed during reaction (2), according to the reaction: MgCO3 + 2CO2 + H2O -> Mg(HCO3)2. (4)

And then the resulting magnesium bicarbonate interacts with Mg(OH)2 according to reaction (2).

When experimentally testing the binder, freshly fired caustic magnesite with an active MgO content of 88% (magnesite-1), aged magnesite with a MgO content of 53.9%, Mg(OH)2 - 34.1% (magnesite-2) and aged magnesite were used with a content of MgO - 38.7%, Mg(OH)2 - 4.03% and MgCO3 - 21.0% (magnesite-3). The specific surface of magnesite powders was 350 m2/kg, the residue on sieve No. 008 was 9.2%.

An aqueous solution of magnesium bicarbonate is prepared by dissolving magnesite-3 in water for 10 minutes at a carbon dioxide pressure in an autoclave of 0.5–1.0 MPa.

In an aqueous suspension of magnesite-3 upon contact with carbon dioxide, the following reactions occur:

MgO + H2O -> Mg(OH)2. (5)

Mg(OH)2 + 2CO2 -> Mg(HCO3)2. (6)

MgCO3 + 2CO2 + H2O -> Mg(HCO3)2.

After treatment in an autoclave with a stirrer (5–10 min), the aqueous solution contained 35–40 g/L Mg(HCO3)2, calculated as an anhydrous substance. It should be noted that the maximum solubility of aqueous magnesium bicarbonate Mg(HCO3)2·2H2O in water is 19 g/100 g of water at 0 °C and 34.5 g/100 g of water at 100 °C.

When preparing samples, a solution of Mg(HCO3)2 was added to the initial magnesite in the previously specified amount until a plastic dough of normal density was obtained, from which samples measuring 2 x 2 x 2 cm were molded. After 24 hours of hardening in air, the samples were removed from the molds and after 3 days hardening in air, some of the samples were placed in water, some of the samples were placed in a desiccator above water, and some of the samples continued to harden in air. After 28 days of hardening, the compressive strength of the samples was determined. The results of the determinations are presented in the table.

Table No. 1. Results of determination of strength and water resistance of samples.

The water resistance coefficient was determined by the ratio of the compressive strength of samples hardened in water to the strength of samples hardened in air. The same table presents the results of determining the strength and water resistance of samples obtained by mixing magnesite-1 with a solution of MgCl2.

Data analysis table. 1 shows that mixing caustic magnesite with an aqueous solution of magnesium bicarbonate makes it possible to obtain products based on magnesium binder with strength not inferior to the strength of products made from classical binder. The high water resistance of products made from experimental binder compositions is due to a fundamentally new composition of poorly soluble hydration products formed during hardening in both air and water environments.

Thus, the use of a fundamentally new mixing fluid makes it possible to transfer magnesium binders from the group of air binders to the group of hydraulic binders, which, like Portland cement, will find wide application in the production of various construction products.

Production

Cement is obtained by finely grinding clinker and gypsum. Clinker is a product of uniform firing before sintering a homogeneous raw material mixture consisting of limestone and clay of a certain composition, ensuring the predominance of calcium silicates.

When grinding clinker, additives are introduced: gypsum CaSO4 2H2O to regulate the setting time, up to 15% active mineral additives (pyrite cinders, flue dust, bauxite, sand) to improve some properties and reduce the cost of cement.

The raw mixture is fired at a temperature of +1450...+1480 for 2-4 hours in long rotary kilns (3.6×127 m, 4×150 m and 4.5×170 m) with internal heat exchange devices to simplify the synthesis of the necessary cement clinker minerals. Complex physical and chemical processes occur in the fired material. The rotary kiln can be divided into zones:

heating (+200...+650 °C - organic impurities burn out and the processes of dehydration and decomposition of the clay component begin). For example, the decomposition of kaolinite occurs according to the following formula: Al2O3 2SiO2 2H2O → Al2O3 2SiO2 + 2H2O; further, at temperatures +600…+1000 °C, aluminosilicates decompose into oxides and metaproducts.
decarbonization (+900…+1200 °C) decarbonization of the limestone component occurs: CaCO3 → CaO + CO2, while the decomposition of clay minerals into oxides continues. As a result of the interaction of basic (CaO, MgO) and acidic oxides (Al2O3, SiO2) in the same zone, processes of solid-phase synthesis of new compounds begin (CaO Al2O3 is an abbreviated form of SA, which at higher temperatures reacts with CaO and at the end of liquid-phase synthesis is formed C3A), proceeding in steps;
exothermic reactions (+1200...+1350 °C) the process of solid-phase sintering of materials is completed, here the process of formation of such minerals as C3A, C4AF (F - Fe2O3) and C2S (S - SiO2) - 3 of the 4 main minerals of clinker - is completed;
sintering (+1300 → +1480 → +1300 °C) partial melting of the material, clinker minerals pass into the melt except C2S, which, interacting with CaO remaining in the melt, forms the mineral alit
(C3S - solid solution of tricalcium silicate and a small amount (2- 4%) MgO, Al2O3, P2O5, Cr2O3 and others);
cooling (+1300…+1000 °C) the temperature decreases slowly. Part of the liquid phase crystallizes with the release of crystals of clinker minerals, and part freezes in the form of glass.

Types and brands of cement

Types of cement

— Portland cement and its varieties are the main binders in construction. Portland cement is a hydraulic binder obtained by finely grinding Portland cement clinker (German klinker: limestone-clay mixture, main clinker minerals: alit 40-60%, aluminate 5-14%, aluminoferrite 10-16%, belite 15-35%, ferrite) with gypsum, as well as with special additives.

— Portal cement clinker is a product of firing a finely dispersed homogeneous raw material mixture consisting of limestone and clay or some materials (marl, blast furnace slag, etc.) before sintering. During firing, a predominant content of highly basic calcium silicates in the clinker is ensured. To regulate the setting time of Portland cement, gypsum dihydrate is added to the clinker during grinding in an amount of 1.5-3.5% (by weight of cement in terms of SO3).

According to the composition they are distinguished:

Portland cement without additives
Portland cement with mineral additives

Cement M500D0 in bags

— Portland cement with moderate exotherm is made from clinker, which should contain no more than 50% tricalcium silicate and no more than 8% tricalcium aluminate. Such cement, with moderate exotherm, is also characterized by slightly increased sulfate resistance, since it usually contains a moderate amount of tricalcium aluminate. This type of Portland cement is used in hydraulic engineering in massive concrete structures subject to frequent alternate freezing and thawing in fresh or slightly mineralized water. The strength grade is usually 300 and 400.

— White cement is made from low-iron clinker (the gray color of ordinary cement is mainly due to the presence of iron compounds in the original raw materials).

— Colored cements are produced on the basis of white Portland cement clinker by co-grinding with pigments of various colors, for example, ocher, red lead, chromium oxide. It is also possible to obtain colored cements by mixing white cement with pigments.

The use of white and colored cements, which contributes to the architectural and decorative design of structures, is of great importance in the industrial finishing of large-element buildings. These cements are also used for colored cement-concrete road surfaces, for example, in areas near monumental buildings. In addition to those listed, there are also some special varieties of Portland cement, for example oil well cement , which is used for the production of asbestos-cement products.

— Rapid-hardening Portland cement contains a lot of tricalcium silicate and tricalcium aluminate and is very finely ground. Therefore, such cement is characterized by an intensive increase in strength in the first period of hardening. Especially fast-hardening cement is also produced. After three days it shows a compressive strength of 450-500 kg/cm2 (when tested in hard solutions).

— Hydrophobic cement is produced by introducing 0.1-0.2% soap naphtha, acidol, oxidized petrolatum, synthetic fatty acids, their bottom residues and other water-repellent surfactants during clinker grinding. These substances, adsorbed on cement particles, form a thin (on average monomolecular, i.e., one molecule thick) shell. But this thinnest shell gives cement special properties. This is the essence of cement hydrophobization as a method that allows, to a certain extent, to control the properties of cement in relation to the action of water at various stages of its use.

As is known, the interaction of cement with water is a two-pronged contradictory process. Affinity for water is organically inherent in cement; without this property it could not serve as a binder. But at the same time, at certain stages of cement use, water is harmful to it. Thus, during storage and transportation, cement deteriorates from moisture, water with impurities contained in it causes corrosion of cement stone and, with frequent alternate freezing and thawing of cement materials, destroys them. The task of overcoming the contradictions inherent in the very nature of cement is, to a certain extent, solved by its hydrophobization. Hydrophobic cement does not deteriorate during transportation and storage, even in very humid conditions. The surfactants contained in it have a plasticizing effect on concrete (mortar) mixtures, and also reduce water permeability and increase the corrosion resistance and frost resistance of concrete. For example, if ordinary concrete can withstand 300 cycles of alternating freezing and thawing, then hydrophobized concrete can withstand 1000 or more cycles. The brands of hydrophobic cement are the same as Portland cement. Hydrophobic cement was first synthesized in our country, and then, based on domestic developments, cement production began abroad.

— Aluminous cement is a fast-hardening hydraulic binder, a product of fine grinding of clinker obtained by firing (before melting or sintering) a raw mixture consisting of bauxite and limestone. Roasting and melting of the raw material mixture is carried out in blast furnaces, electric furnaces, rotary furnaces or cupola furnaces. Based on the Al2O2 content in the finished product, the following are distinguished:

ordinary aluminous cement (up to 55%)
high alumina cement (up to 70%)

The melting temperature of the raw material mixture of ordinary alumina cement is about 1450-1480°C, and high-alumina cement is about 1700-1750°C. Aluminous cement is characterized by a rapid increase in strength, high exotherm during hardening, increased resistance to corrosion in sulfate environments and high fire resistance. Compared to Portland cement, aluminous cement provides concrete and mortars with greater density and water resistance.

— Magnesia cement is used for the construction of magnesia floors, as a magnesia binder, which is a fine powder, the active part of which is magnesium oxide. Magnesium oxide, in turn, is a product of moderate firing of natural carbonate rocks of magnesite or dolomite. When mixed with water, magnesium oxide hydrates very slowly, exhibiting weak astringent properties. However, when mixed with aqueous solutions of certain salts, a durable cement stone is formed. In particular, when mixed with magnesium chloride (bischofite), a binder is obtained called Sorel cement .

In many properties, magnesia cements are superior to Portland cement: they have elasticity, resistance to oils, greases, organic solvents, alkalis and salts, do not require wet storage during the hardening process, provide high fire resistance and low thermal conductivity, good wear resistance and compressive and bending strength in at an early age. A very significant fact is that magnesium binders are characterized by increased adhesion strength to various types of fillers, both inorganic and organic. All these qualities determine their use in abrasive production (grinding wheels), for the manufacture of thermal insulation products (foam and gas magnesite) and partitions, window sill slabs, stair steps, and less often - for facing tiles in the interior of the room and small architectural forms. However, their main use was and remains the construction of seamless monolithic floors. Using various polymers, floor manufacturers have the opportunity to prime the surface of the base on which magnesium concrete is laid so that the primer simultaneously serves as a waterproofing and is vapor-permeable. Polymer impregnation of the top layer (to a thickness of 2-3 mm) allows you to protect against moisture from penetrating into the concrete from above. In addition, using new technologies and materials, both organic and inorganic, it is possible to obtain a water-resistant magnesium binder.

— Plasticized cement is produced by adding about 0.25% of sulfite-alcohol stillage (calculated on a dry matter basis) by weight of cement when grinding clinker. This surfactant plasticizes concrete mixtures, mainly fatty ones, makes it possible to reduce the water-cement ratio without compromising the mobility of the mixtures and, in some cases, makes it possible to reduce cement consumption. At the same time, the frost resistance of hardened concrete increases.

— Pozzolanic cement is the collective name for a group of cements that contain at least 20% active mineral additives. The term “pozzolanic cement” comes from the name of loose volcanic rock - pozzolan, which was used in ancient Rome as an additive to lime to produce a hydraulic binder, the so-called. lime-pozzolanic cement. In modern construction, the main type of pozzolanic cement is pozzolanic Portland cement, obtained by joint grinding of Portland cement clinker (60-80%), active mineral additive (20-40%) and a small amount of gypsum. It differs from ordinary Portland cement in its increased corrosion resistance (especially in soft and sulfate waters), lower hardening rate and reduced frost resistance. Pozzolanic cement is used mainly to produce concrete used in underwater and underground structures.

— Expanding cement is the collective name for a group of cements that have the ability to increase in volume during hardening. For most expansive cements, expansion occurs as a result of the formation in the medium of the hydrating binder of highly basic calcium hydrosulfoaluminates, the volume of which, due to the large amount of chemically bound water, significantly (1.5-2.5 times) exceeds the volume of the original solid components. The total expansion of expansive cement is 0.2-2%. The strength of expanding cement is 30-50 Mn/m2. In Russia, the most widespread among expanding cements are:

waterproof expanding cement
gypsum alumina expanding cement
tension cement

All expansive cements harden better and exhibit greater expansion under wet conditions. Due to their high water resistance, expanding cements are used for sealing joints of prefabricated reinforced concrete structures, creating reliable waterproofing during the construction of some hydraulic structures, the production of pressure reinforced concrete pipes, etc. is a fast-setting and fast-hardening hydraulic binder obtained by co-grinding and thoroughly mixing crushed aluminous cement, gypsum and highly basic calcium hydroaluminate. The cement is characterized by rapid setting: the start of the process is less than 4 minutes, the end is no later than 10 minutes from the moment of mixing. The linear expansion of cement paste samples hardening in water for 1 day should be within 0.3-1%. Waterproof expanding cement is used for caulking and waterproofing seams of tubings, socket joints, creating waterproofing coatings, sealing joints and cracks in reinforced concrete structures, etc.

— Sulfate-resistant cement is made from clinker of a standardized mineralogical composition: the clinker should contain no more than 5% tricalcium aluminate and no more than 50% tricalcium silicate. A low limiting content of tricalcium aluminate is required because sulfate corrosion develops as a result of the interaction of sulfates in the environment with tricalcium hydroaluminate of cement stone. If C3 Al is present in small quantities in cement stone, then a small amount of calcium hydrosulfoaluminate is formed. Then it is not dangerous, since it is distributed in the pores of the concrete, displacing water or air from there, and does not cause internal stresses in the concrete. In small quantities, calcium hydrosulfoaluminate is sometimes even useful, as it compacts concrete. In the clinker of sulfate-resistant Portland cement, the content of tricalcium silicate is also limited to reduce the amount of heat generated by the cement. Therefore, sulfate-resistant Portland cement has increased sulfate resistance and reduced exotherm, i.e. qualities necessary for the production of concrete for certain areas of hydraulic engineering and other structures operating under conditions of sulfate aggression. Sulfate-resistant Portland cement is usually produced in two grades: 300 and 400.

Cement JSC Mordovcement in 50 kg bags.

— Well cement is a type of Portland cement intended for cementing oil and gas wells. Well cement is produced by joint fine grinding of clinker and gypsum. In Russia, two types of well cement are produced: for so-called cold (with temperatures up to -40°C) and hot (up to +75°C) wells. Well cement is used in the form of cement paste containing 40-50% water.

— Slag cement is the general name for cements obtained by co-grinding granulated blast furnace slag with activating additives (lime, building gypsum, anhydrite and others) or by mixing these separately crushed components. There are the following types of slag Portland cement: lime-slag with a lime content of 10-30% and gypsum up to 5% by weight of cement and sulfate-slag with a gypsum or anhydrite content of 15-20%, Portland cement up to 5% or lime up to 2%. Slag cement is used to produce mortars and concretes, used primarily in underground and underwater structures. Lime-slag cement is most effective in the production of autoclave materials and products.

leave a request for cement

PRICE LIST FOR CEMENT as of 07.07.2020
Product name	Price in rubles per ton including delivery by road to Moscow and the Moscow region
Cement TSEM I 42.5N NAVAL with delivery by cement trucks	5150
Cement CEM II 32.5N (M400 D20) NAVAL with delivery by cement trucks	4950
Cement CEM I 42.5-N (M500 D0) NAVAL with delivery by cement trucks	5250
Portland cement "Asia Cement" CEM I 42.5N (M500 D0) in 50kg bags on pallets	5800
Portland cement "Asia Cement" CEM II 42.5N (M500 D20) in 50kg bags on pallets	5700
Portland cement in big bags "Eurocement" CEM I 42.5N (M500 D0) big bags	5700
Portland cement "Asia Cement" CEM II 32.5N (M400 D20) in 50kg bags on pallets	5600
White cement CEM I 52.5R Adana cimento in 50kg bags	14000/14500*
White cement CEM I 52.5R Adana cimento in big bags 1.25 tons.	13600/14100*
White cement “Aalborg White” (Egypt) CEM I 52.5 N (big bags)	13900/14500*
White cement “Aalborg White” (Egypt) CEM I 52.5 N (50 kg bags)	14000/15500*
White cement CIMSA (Turkey) CEM I 52.5 N big bag 1 ton.	15100/15500*
White cement CIMSA (Türkiye) CEM I 52.5 N bags 50 kg.	15100/15500*
White cement Aalborg White (Denmark) M-700 CEM I 52.5 R bags 25 kg.	17000/18000
Aluminous cement ISIDAC 40 (Türkiye) bags 25 kg.	39900/44000*
Aluminous cement SRB-400 (Secar 38R) (France) bags 25 kg.	43000/44000*
Aluminous cement GC-40 (Russia) 50 kg bags.	36000/40000*
Aluminous cement GC-50 (Russia) 50 kg bags.	40500/48000*
Aluminous cement GC-60 (Russia) 50 kg bags.	44000/50000*
Expanding gypsum-alumina cement GGTSR (Russia) (50 kg bags)	38500/40000*
Tensile cement NTs-20 bags 20 kg.	14500/15000*

* — price from warehouse in Moscow from 1 bag.

World cement production

In 2010, global cement production reached 3.325 billion tons. The three largest producers included China (1.8 billion tons), India (220 million tons), and the USA (63.5 million tons). According to Rosstat, production in Russia of Portland cement, aluminous cement, slag cement and similar hydraulic cements in 2012 amounted to 61.5 million tons.

The largest cement producers in the world for 2011[2]:

Holcim - Switzerland - 136.7 million tons
Lafarge - France - 150.6 million tons
Heidelberg Group - Germany −176 million tons (as of July 1, 2020)
Cemex - Mexico - 74.0 million tons
Italcementi - Italy - 54.4 million tons
Anhui Conch Cement - China - 41.5 million tons
Taiheiyo Cement - Japan - 38.0 million tons
Votorantim Cimentos - Brazil - 31.8 million tons
Buzzi Unicem+Dyckerhoff - Italy-Germany - 26.6 million tons
Cimpor - Portugal - 28.3 million tons
Vicat - France - 19.8 million tons[3]
Eurocement group - Russia - 18.4 million tons

Cement production in Russia

Ten leading cement producers in Russia for 2013 (volume in million tons / market share in %)[4]:

Eurocement group - 21,649 / 32.6
Novoroscement - 5.772 / 8.7
"Mordovtsement" - 4.717 / 7.1
"Siberian Cement" - 4.307 / 6.5
Heidelberg Cement - 3.654 / 5.5
Holcim - 3.658 / 5.5
Dyckerhoff - 3.257 / 4.9
Sebryakovcement - 3.167 / 4.8
Lafarge - 2.416 / 3.6
"Vostokcement" - 2.037 / 3.1

Design capacity of the plants at the end of 2014 (million tons per year):

"Eurocement group" - 33.1
"Mordovcement" - 7.2
"Novoroscement" - 6.9
"Siberian Cement" - 6.7
Heidelberg Cement - 4.9
Holcim - 4.6
"Vostokcement" - 4.3
Dyckerhoff - 3.7
"Sebryakovcement" - 3.4
"Bazelcement" - 3.2

In December 2014, Mordovcement enterprises came under the control of Eurocement Group.[5]:

Marking of heat-resistant cement

Regulatory document GOST 969-91. “Aluminous and high-alumina cements”, depending on the content of aluminum oxide (Al₂O₃) in the binder, differentiates heat-resistant cement into the following types:

Aluminous material GC.
High-alumina material VGC I, VGC II, VGC III.

Depending on the achieved concrete strength within 72 hours, GOST 969-91 differentiates cement into the following grades:

GC 40, GC 50, GC60.
VGC I-35.
VGC II-25, VGC-35.
VGC III-25.
VGTs 70-VGTs 75
VGKTs-70-1.

Arabic numerals, 40,50,60,25 and 35, inform the consumer that a concrete material based on one or another type of refractory cement, 72 hours after mixing, under standard curing conditions (air temperature 20-25 °C, 75- 80% relative humidity) will have a compressive strength of 40 MPa, 50 MPa, 60 MPa, etc.

An example of the designation of heat-resistant cement: Fire-resistant cement Hz 40 GOST 969-91. Fire-resistant aluminous cement. The achieved compressive strength 72 hours after mixing the concrete mixture is 40 MPa or 400 kgf/cm2. Empirical fire resistance 780-1,000°C. The fire resistance of this type of binder is not regulated by GOST 969-91.

Notes

↑ 12
Construction materials science: A textbook for construction specialists. universities / I. A. Rybyev. - M.: Higher. school, 2003. - 701 p.
Vladimir Kondratyev
- [World Cement Industry], Perspectives Portal, 2011
Vicat Group by the numbers.
Top 10 largest cement producers in Russia, Kommersant, April 8, 2014.
Independent construction portal. Top 10 cement producers in Russia. 02/25/2015.

Portland cementand its varieties are the main binders in construction. Portland cement is a hydraulic binder obtained by finely grinding Portland cement clinker with gypsum, as well as special additives.

Portal cement clinker is a product of firing a finely dispersed homogeneous raw material mixture consisting of limestone and clay or some materials (marl, blast furnace slag, etc.) before sintering. During firing, a predominant content of highly basic calcium silicates in the clinker is ensured. To regulate the setting time of Portland cement, gypsum dihydrate is added to the clinker during grinding in an amount of 1.5-3.5% (by weight of cement in terms of SO3).

Based on their composition, they are divided into: Portland cement without additives; Portland cement with mineral additives; slag Portland cement and others.

White Portland cement

Ordinary Portland cement has a greenish-gray color due to its relatively high content of coloring oxides: iron oxide and manganese oxide. Clinker, which does not contain these oxides or contains them in small quantities (Fe2O3 0.3-0.5%, MnO up to 0.03%), is white. This is achieved by using appropriate raw materials - white particles of clays, kaolins and limestones with a minimum content of these oxides.

White Portland cement, unlike ordinary cement, has an increased silicate modulus (3.0-3.8) and a very high alumina modulus (10 or more), and the saturation coefficient is lower than that of ordinary cement - 0.80-0.87. in accordance with this, white Portland cement clinker has the following mineralogical composition: C3S 38-44%; C2S 35-37%; C3A 15-16%; C4AF 1-2%, i.e. it contains virtually no calcium aluminoferrites. White Portland cement clinker is fired at a higher temperature due to the low flux content. To increase the whiteness of cement, the clinker is “bleached” when leaving the kiln, sharply cooled with water to a temperature of 500-6000 C, or exposed to an oxygen-free reducing environment at a temperature of 800-10000 C, followed by cooling in an oxygen-free environment to 200-3000 C.

With sudden cooling and as a result of the action of a reducing environment, the degree of whiteness of the clinker increases due to the transition of part of the oxide iron to ferrous iron and also due to the formation of calcium aluminoferrite, which binds a larger amount of Fe2O3, C6AF2. In accordance with the requirements of GOST 965-66, white Portland cement is divided into grades 300, 400 and 500, and according to the degree of whiteness it is divided into three grades: highest, BC-1 and BC-2, determined by the brightness coefficient relative to BaSO4. White Portland cement should contain no more than 6% white diatomaceous earth and no more than 10% inert mineral additive (limestone, quartz sand). Magnesium oxide in clinker should be no more than 4%. The remaining requirements are the same as for ordinary Portland cement.

On the basis of white cement, colored cements are prepared by adding pigments - finely ground mineral dyes - when grinding white clinker: mummy (red pigment), umber (brown), ocher (yellow), chromium oxide (green), soot (black), ultramarine (blue) .

Rapid hardening Portland cement

Rapid-hardening Portland cement differs from ordinary cement in a more intensive increase in strength in the initial period of hardening.

It can be obtained either by finer grinding of ordinary clinker, or by using clinker of a certain mineralogical composition. However, increasing the fineness of cement grinding is unprofitable, since this reduces the productivity of grinding equipment and increases energy consumption. Therefore, a more profitable way to obtain fast-hardening cement is to regulate the mineralogical composition of clinker.

Cements with a high total content of tricalcium silicate and tricalcium aluminate (at least 60%) are, as a rule, fast-hardening. In this case, the C3S content should be at least 50-52%, and C3A - 8-10%.

The acceleration of cement hardening in the initial period is also facilitated by a decrease in the content of active mineral additives in it. The content of the latter in quick-hardening Portland cement should not exceed 10%; The exception is granulated blast furnace slag, which has some astringent properties, and therefore their content in quick-hardening Portland cement is allowed no more than 15%.

According to GOST 10178-62, after 3 days of hardening under standard conditions in a 1:3 solution, BTC must have a bending strength of at least 40 kgf/cm2. The 28-day strength of quick-hardening Portland cement is not regulated and is characterized by an approximate grade of 400. The grinding fineness of BTC is higher than that of ordinary Portland cement (2500-3000 cm/g2), and amounts to 3500-4000 cm/g2.

A type of fast-hardening Portland cement is extra-fast-hardening Portland cement (OBTC). It differs from BTC in an even more intense rate of increase in strength in the initial period of hardening.

Extra-fast-hardening Portland cement is obtained in the same way as BTC. The mineralogical composition of the clinker of especially fast-hardening Portland cement OBTC must be such that the content of tricalcium silicate in it is 60% or more, and tricalcium aluminate - no more than 8%. Particularly fast-hardening Portland cement grade 600 should have a compressive strength of 200-250 kgf/cm2 at one day of age, and 300-350 kgf/cm2 at three days of age.

OBTC is crushed to a specific surface area of 4000-4500 cm/g2. With very fine grinding, it is advisable to increase the gypsum content in this cement to 4% (calculated as SO3), i.e. slightly higher than the limit allowed by the standard (3.5%). The addition of 5-8% tripoli promotes a uniform increase in strength by 28 days of age, although at the same time the one-day strength is slightly reduced.

Waterproof Expanding Cement

Waterproof expanding cement is a fast-setting and fast-hardening hydraulic binder obtained by co-grinding and thoroughly mixing crushed aluminous gypsum cement and highly basic calcium hydroaluminate. The cement is characterized by rapid setting: the start of the process is earlier than 4 minutes. end no later than 10 minutes. from the moment of confinement.

Linear expansion of cement paste samples hardening in water for 1 day. should be between 03-1%.

VRC is used for caulking and waterproofing seams, tubings, socket joints, creating waterproofing coatings, sealing joints and cracks in reinforced concrete structures, etc.

Hydrophobic Portland cement

Hydrophobic Portland cement is produced by introducing a hydrophobic additive during grinding of ordinary Portland cement. These additives include: asidol, asidol-mylonaft, mylonaft (GOST 13302-67), oleic acid or oxidized petrolatum.

Additives are introduced in an amount of 0.06-0.30% by weight of cement in terms of dry matter. The optimal content of the additive is established experimentally for each cement and depends on the type of additive, grinding fineness and mineralogical composition of the clinker.

The standard requirements for hydrophobic Portland cement remain the same as for ordinary cement, but, in addition, hydrophobic cement must have a special property - it must not absorb water within 5 minutes.

Hydrophobic Portland cement differs from ordinary cement in its reduced hygroscopicity. Reduced hygroscopicity allows cement to remain active during long-term transportation and storage, even in a humid environment, and prevents sticking into lumps during short-term exposure to water. In addition, hydrophobic cements give concrete increased frost resistance and water resistance. When using hydrophobic Portland cement, the mobility and workability of concrete mixtures slightly increases.

Alumina cement

Alumina cement is a fast-hardening hydraulic binder; a product of fine grinding of clinker obtained by firing (before melting or sintering) a raw material mixture consisting of bauxite and limestone. Roasting and melting of the raw material mixture is carried out in electric rotary blast furnaces or cupola furnaces. Based on the Al2O3 content in the finished product, a distinction is made between ordinary alumina cement (up to 55%) and high-alumina cement (up to 70%). the melting temperature of the raw material mixture of ordinary alumina cement is 1450-1480 C, high-alumina cement is 1700-1750 C.

Aluminous cement is characterized by a rapid increase in strength, high exotherm during hardening, increased resistance to corrosion in sulfate environments and high fire resistance. Compared to Portland cement, aluminous cement provides concrete and mortars with greater density and water resistance.

Carbonate Portland cement

Carbonate Portland cement is a product of joint fine grinding of clinker with 25-30% carbonate rocks. Carbonate cement is characterized by the following main indicators: the grinding fineness must correspond to a specific surface of at least 3500 cm2 /g, while the residue on sieve - 02 should not exceed 2%, and at least 92% of the material must pass through sieve - 008; the beginning of setting should occur no earlier than 30 minutes, and the end no later than 5 hours. To make this cement, it is advisable to use clinker with the highest possible content of C3A and C4AF.

When carbonate Portland cement hardens, less heat is generated than when ordinary Portland cement hydrates. In addition, it is characterized by increased resistance in carbonic environments due to the protective effect of calcium carbonate.

Magnesia cement

To install magnesium floors, magnesium binder is used, which is a finely dispersed powder, the active part of which is magnesium oxide. Magnesium oxide, in turn, is a product of moderate firing of natural carbonate rocks of magnesite or dolomite. When mixed with water, magnesium oxide hydrates very slowly, exhibiting weak astringent properties. However, when mixed with aqueous solutions of certain salts, a durable cement stone is formed. In particular, when mixed with magnesium chloride (bischofite), a binder called Sorel cement is obtained.

Many properties of magnesia cements are better than those of Portland cement: they have elasticity, resistance to oils, lubricants, organic solvents, alkalis and salts, do not require wet storage during the hardening process, provide high fire resistance and low thermal conductivity, good wear resistance and compressive and bending strength at an early age. A very significant fact is that magnesium binders are characterized by increased adhesion strength to various types of fillers, both inorganic and organic.

All these qualities determine their use in abrasive production (grinding wheels) for the manufacture of thermal insulation products (foam and gas magnesite) and partitions for window sill slabs of stair steps, less often - for facing tiles of the interior of the room and small architectural forms. However, their main use was and remains the construction of seamless monolithic floors.

Magnesia cements began to be used for these purposes already at the end of the 19th and beginning of the 20th centuries, and so-called xylolite floors and slabs were produced. Xylolite is concrete based on magnesium binder and includes sawdust as a filler. Later, products made from fiberboard appeared, in which various fibers served as filler. Such floors were dust-free (due to low abrasion), were quite easy to sand, and could be rubbed with mastics. The floors were hygienic, non-flammable and durable. However, this is also their significant drawback: magnesium concrete floors are characterized by low water resistance and require protection from moisture, especially from below from capillary suction of water through the base and from the side through the walls. In connection with this and also with the scarcity of raw materials (primarily magnesites are used to produce refractories), there were no prospects for magnesia binders. And only now, with the advent of new deposits, as well as with the expanding capabilities of polymer chemistry, magnesium floors have received a new takeoff.

Using various polymers, floor manufacturers have the opportunity to prime the surface of the base on which magnesium concrete is laid so that the primer simultaneously serves as waterproofing and is vapor-permeable. Polymer impregnation of the top layer (to a thickness of 2-3 mm) allows you to protect against moisture from penetrating into the concrete from above. In addition, using new technologies and materials, both organic and inorganic, it is possible to obtain a water-resistant magnesium binder. Our company has such materials and technologies in service and it is impossible to use them at sites.

Tensile cement

Tensing cement is a type of expanding cement obtained by joint grinding of Portland cement clinker (65%), aluminous slag (15%), gypsum stone and lime (5%).

Tensing cement is a quick-setting and quick-hardening binder: the strength of solutions (1:1 composition) after 1 day reaches 20-30 Mn/m2 (200-300 kgf/cm2). Cured tensile cement is highly impermeable to water.

Expanding during the hardening process, prestressing cement develops high pressure - 3-4 Mn/m2 (30-40 kgf/cm2) which can be used to produce pre-stressed reinforced concrete structures with reinforcement tension in one or several directions. It is advisable to use prestressing cement for the production of pressure pipes for the construction of capacitive structures and some thin-walled reinforced concrete structures.

Sandy Portland cement

Sandy Portland cement is obtained by combining fine grinding of clinker, adding gypsum and approximately 40% quartz sand.

A distinctive feature of this cement is its reduced heat generation during hydration.

Plasticized Portland cement

Plasticized Portland cement is produced by introducing plasticizing surfactant additives during grinding of ordinary Portland cement. Concentrates of sulfite-alcohol mash (SDB), which meets the requirements of MRTU 13-04-35-66, are used as surfactant additives.

The additive is introduced in dry form or in the form of an aqueous solution in an amount of 0.15-0.25% by weight of cement in terms of dry matter. The optimal additive content for a given cement is established experimentally and depends on the mineralogical composition of the clinker, the fineness of cement grinding and the content of hydraulic additives in it.

The basic properties of plasticized Portland cement and the requirements imposed on them by the standard are the same as those of ordinary Portland cement, with the exception of the requirement for its plasticity. A solution made from a mixture of plasticized Portland cement with normal sand of the composition 1: 3 with a water-cement ratio of 0.40 must have such plasticity that the spread of the cone from this solution after 30 shakings is at least 125 mm. Under the same conditions, ordinary Portland cement produces a cone spread of 105-110 mm.

Plasticized Portland cement differs from ordinary cement in its ability to impart increased mobility (fluidity) to concrete mixtures, which ensures their easier placement and compaction when forming concrete products. Since the mobility of concrete mixtures depends mainly on the water content, the use of plasticized Portland cement makes it possible to reduce the water content of the mixture without changing its mobility. This in turn allows you to save cement, increase the strength and frost resistance of concrete.

Pozzolanic cement

Pozzolanic cement is the collective name for a group of cements that contain at least 20% active mineral additives.

The term “pozzolanic cement” comes from the name of the loose volcanic rock, pozzolan, which was used in ancient Rome as an additive to lime to produce the so-called hydraulic binder. lime-pozzolanic cement.

In modern construction, the main type of pozzolanic cement is pozzolanic Portland cement, obtained by joint grinding of Portland cement clinker (60-80%), an active mineral additive (20-40%) and a small amount of gypsum. It differs from ordinary Portland cement in its increased corrosion resistance (especially in soft and sulfate waters), lower hardening rate and reduced frost resistance. Pozzolanic cement is used mainly to produce concrete used in underwater and underground structures.

Expanding cement

Expanding cement is the collective name for a group of cements that have the ability to increase in volume during hardening.

In most expansive cements, expansion occurs as a result of the formation in the medium of the hydrating binder of highly basic calcium hydrosulfoaluminates, the volume of which, due to the large amount of chemically bound water, significantly (15-25 times) exceeds the volume of the original solid components.

The total expansion of expansive cement is 02-2%. The strength of expanding cement is 30-50 Mn/m2.

In the USSR, the most widely used expansive cements are waterproof expansive cement, expansive Portland cement, gypsum alumina expansive Portland cement, and tensile cement. All expansive cements harden better and exhibit greater expansion under wet conditions. Due to their high water resistance, expanding cements are used to seal joints of prefabricated reinforced concrete structures to create reliable waterproofing during the construction of some hydraulic structures, the production of pressure reinforced concrete pipes, etc.

Sulfate resistant Portland cement

Sulfate-resistant Portland cement differs from ordinary cement in its higher resistance to sulfate waters.

The reason for the destruction of hardened cement in water containing dissolved sulfates is the interaction of calcium sulfate with tricalcium aluminate according to the reaction C3AH6 + 3CaSO4 * 2H2O + 19H2OC3A * 3CaSO4 * 31H2O.

The resulting calcium hydrosulfoaluminate, called the “sulfoaluminate bacillus” because of its destructive action, increases significantly in volume compared to the total volume of the starting materials - tricalcium aluminate and gypsum - due to the addition of a large amount of water. This causes the appearance of tensile stresses in the cement stone and its subsequent destruction.

One of the main ways to obtain sulfate-resistant cement is to reduce the content of tricalcium aluminate in clinker, at the first stage of interaction of which with water tricalcium hydroaluminate is formed when there is a lack of gypsum.

The sulfate resistance and water resistance of Portland cement are reduced with a high content of tricalcium silicate in the clinker, which, upon hydration, releases easily soluble calcium oxide hydrate. For these reasons, sulfate-resistant Portland cement clinker should contain no more than 50% tricalcium silicate; tricalcium aluminate should not exceed 5%, and the sum of tricalcium aluminate and tetracalcium aluminoferrite should be no more than 22%.

Sulfate-resistant Portland cement is produced in two grades - 300 and 400. The introduction of active mineral additives into this cement is not allowed, as they reduce the frost resistance of concrete.

Well cement

Well cement is a type of Portland cement; designed for cementing oil and gas wells.

Well cement is produced by joint fine grinding of clinker and gypsum. In the USSR, two types of well cement are produced: for so-called cold (with temperatures up to 40 C) and hot (up to 75 C) wells.

Well cement is used in the form of cement paste containing 40-50% water.

Slag cement

Slag cement is the general name for cements obtained by co-grinding granulated blast furnace slag with activating additives (lime, gypsum anhydrite, etc.) or by mixing these separately crushed components.

There are Sh. ts. lime-slag with a lime content of 10-30% and gypsum up to 5% by weight of cement and sulfate-slag with a gypsum or anhydrite content of 15-20%, Portland cement up to 5% or lime up to 2%. Slag cement is used to produce mortars and concretes used primarily in underground and underwater structures. Lime-slag cement is most effective in the production of autoclave materials and products.

Surf Source: https://cement.ru