Limestone is a rock that formed in shallow sea waters in the form of precipitated compounds approximately 300 million years ago. Limestone is of organic origin and consists of calcium carbonate. Like most sedimentary rocks, it consists of many layers.
Application of limestone
This breed is in great demand in the construction industry. The main properties of limestone that determine such prevalence:
- long period of operation
- homogeneous structure
- high level of structural strength
- pure color
- high level of thermal insulation
- ease of processing
- affordable price.
In addition, limestones are in demand in metallurgy, food, pulp and paper, coke, glass and paint industries. It is widely used as: crushed stone, limestone pieces, rubble stones, crushed sand and mineral chips and for releasing construction lime. When constructing roads, limestone is used to protect hydraulic structures. It is possible to use limestone in electric welding and thermal insulation of technological equipment. It is noteworthy that this is the only breed that has 100% protection against radiation.
Characteristics of limestone
In Russia, limestone is found everywhere, as well as in the territory North America. But in Australia there is no such breed. Since the formation of lime deposits continues continuously, limestone is considered an inexhaustible rock. Both marble and fragile chalk, coral reefs and shell rock are limestones.
According to physical and chemical indicators, limestone stone is not highly resistant. In any conditions, it will dissolve in water, therefore all earthly waters, with the exception of atmospheric vapors, contain limestone to one degree or another.
The density of limestone ranges from 2700 to 2900 kg/m3. The compressive strength of limestone ranges from 0.4 MPa for shell rock to 300 MPa for crystalline and aphanitic limestone. Wet limestone has much lower density. When wet, the strength of limestones often decreases.
| Name of indicators | Norm for grade 1 | Norm for grade 2 | Test method |
|---|---|---|---|
| Sum of calcium and magnesium oxides, %, not less | 54,0 | 53,0 | According to GOST 2642.7-97 |
| Mass fraction of magnesium oxide, %, no more | 3,5 | 3,5 | According to GOST 2642.8-97 |
| Mass fraction of silicon dioxide, %, no more | 1,5 | 2,0 | According to GOST 2642.3-97 |
| Mass fraction of sulfur, %, no more | 0,06 | 0,09 | |
| Mass fraction of phosphorus, %, no more | 0,03 | 0,03 | Indicators are determined in accredited laboratories using approved methods once every six months |
Types of limestone
There are many classifications of limestone rocks. Based on structural features, they are distinguished:
- dolomitized, containing approximately 4-17% magnesium oxide. As the volume of magnesium increases, this rock transforms into dolomite
- marbled, are carbonate limestones. They contain many organic fossils of mollusk shells
- coral They are hard, but have a porous structure. They form reefs from mollusk shells and the shells of other ancient sea inhabitants
- clayey. Their composition is something between limestone and marl.
By origin there are the following limestones:
- Jurassic (marble). This breed is characterized by high strength and density. It can be polished
- Putilovsky. This breed has unique physical characteristics, low percentage of liquid absorption. It is extracted from the Putilovsky quarry, which is located in the Leningrad region.
By area of application there are:
- flux. This rock is the main raw material for the production of flux, widely used in metallurgy for metal smelting
- facing limestone is a building stone of organic origin, used for cladding exteriors and interiors of premises.
Obtaining limestone
Limestone is part of the rock, so it can be separated using two methods:
- using a controlled explosion
- using special technology.
In both cases, rubble pieces are obtained, which are sent by conveyor to the storage location. After this, large pieces are cut into smaller ones using diamond wheels.
Further processing depends on the scope of use of this material:
- crushing into special machines allows you to obtain a fine and medium fraction, which is a filler, for example, for asphalt concrete
- cutting with saws makes it possible to obtain facing slabs with a smooth or chipped surface
- processing to produce lime.
Organic, less often chemogenic origin, consisting predominantly of calcium carbonate (CaCO 3) in the form of calcite crystals of various sizes.
Limestone, consisting mainly of shells of marine animals and their fragments, is called shell rock. In addition, there are nummulitic, bryozoan and marble-like limestones - massively layered and thin-layered. During metamorphism, limestone recrystallizes and forms marble.
Deposits
Limestone is a widespread sedimentary rock formed with the participation of living organisms in sea basins. This is a monomineral rock consisting of calcite with impurities. The name of a variety of limestone reflects the presence in it of remains of rock-forming organisms, area of distribution, structure (for example, oolitic limestones), impurities (ferruginous), nature of occurrence (limestone), geological age (Triassic).
Entire mountain ranges in the Alps and Crimea are made of limestone, and it is also widespread in other places. Limestone has no shine, it is usually light-colored gray, but can be white or dark, almost black; bluish, yellowish or pink, depending on the composition of the impurities. The remains of ancient animals are found in the limestone.
In Russia, limestones are common in the central regions of the European part, and are also common in the Caucasus, the Urals and Siberia.
The deposits of the Russian Platform are widely known, the limestones of which were traditionally used for construction and exterior decoration of buildings. Today, the raw material base of these limestones, including the white limestones of the Myachkovsky horizon, is very limited.
One of the most promising limestone deposits is the Zhdanovskoye deposit (Orenburg region), discovered in 2015, where industrial mining of Sarmat limestone is currently underway. The deposit supplies limestone with high quality indicators, has large reserve volumes and shallow beds. The physicochemical properties of limestone from the Zhdanovsky deposit are given below.
Limestone stone is a sedimentary rock of predominantly biogenic origin, which is presented in a wide variety of forms and varieties. Many mountain ranges, coral reefs, lime deposits, chalk cliffs and strata in the thickness of the earth's crust are composed of it. It was formed in different geological eras and in different conditions, which led to the appearance of so many of its varieties.
What substance is the basis of limestone?
The basis of limestone is the same substance - calcium carbonate (formula: CaCO3). This means that, despite the abundance of forms and variations, all limestones have much in common. First of all, it is the ability to gradually dissolve in water and acids, the tendency to get wet when exposed to moisture, hygroscopicity, and relative softness, making it easy to process.
When heated, limestone decomposes into calcium oxide (CaO) and carbon dioxide(CO2). The decomposition reaction of limestone is used in the production of lime. One more distinctive feature of this material - the biological origin of most of its mass, the presence of imprints of mollusks and other living creatures, whose sediments became part of it
The oldest deposits are hundreds of millions of years old. The main place of its formation and accumulation was the bottoms of seas and reservoirs.
This rock is also interesting because under the influence of water, underground voids and caves are formed in it, many of which have become recreational sites. The caves were actively used by ancient people.
How is limestone used?
This breed is widely used in various fields:
- Construction and cladding. Limestone in construction is used in the production of mixtures, cement, lime, as well as for cladding walls, stairs, balconies, fireplaces, floors (finishing slabs, etc.).
- Road construction. Lump material is used to create embankments and compact soil. Preference is given to materials with a higher bulk density. It usually increases as the particle size decreases.
- In the metallurgical industry. The addition of limestone improves and facilitates the process of smelting metals and creating alloys.
- In the manufacture of heat-resistant glass.
- IN chemical industry: production of rubber, soda, varnishes and paints.
- As a filter material for water purification and food industry.
- For other types of production: manufacturing mineral fertilizers, soap, printing products.
Properties of limestone
Physical properties depend significantly on its composition and structure. Hardness varies greatly depending on its variety. Loose rocks (for example, shell rock) have a volumetric mass of only 800 kg/m3, while for limestones with a crystalline structure it can reach 2900 kg/m3.
Compressibility depends on porosity and ranges from 0.4 MPa to 300 MPa. The lowest compressive resistance is characteristic of shell rock, and the highest is characteristic of crystalline rocks. When wet, it becomes less hard and its strength decreases.
The same deposit may contain limestones with different strength values. Loose rocks such as shell rock and chalk are characterized by high abrasion and crushability. In general, these indicators are higher for limestone than, for example, for granite or marble. Brittle limestones have less frost resistance and are difficult to polish, but they are easy to saw and take the desired shape.
Denser versions of this species, on the contrary, polish well, but are harder to saw. They also have higher frost resistance - from 300 to 400 cycles of freezing and subsequent defrosting.
Varieties of limestone
All limestones are divided according to origin, color, chemical composition, physical properties, structure, application features.
The most common colors of this breed are:
- White or greyish. Chemically pure limestone rocks, consisting almost exclusively of calcium carbonate, have this color.
- Brown and yellow colors are due to the presence of iron compounds.
- Red, pink and brown limestone is obtained in the presence of an admixture of manganese compounds.
- The green color of this rock is given by the remains of seaweed.
- Dark and black colors are associated with the presence of heavy hydrocarbon fractions in this rock. These types of limestone are very rare.
ORIGIN OF LIMESTONE ROCKS CAN BE BIOGENIC, CHEMOGENIC AND SECONDARY
In the first case (the most common option), the reason for their formation is the accumulation of calcareous shells and other fossils in the thickness of the seabed. In the second - chemical transformations during which calcium carbonate is formed. IN the latter case the formation of new strata is associated with the natural transformation of previously destroyed limestones.
Based on the time of occurrence, Jurassic, Triassic, Cretaceous limestones and other types are distinguished. The name of limestone corresponds to the geological period within which its formation took place. Since natural conditions were different in different eras, the limestones themselves were not the same. The composition of the imprints of ancient organisms also depends on the time of occurrence, since in different geological periods the different types living beings.
Limestones are also classified by variety. The following types are common:
- Dolomitized. Contain a significant admixture of magnesium oxide. At its maximum content, dolomites are obtained.
- Coral. They are formed in modern warm seas and form the basis of coral reefs. They have a porous consistency.
- Clayey. Such rocks contain a significant admixture of clay. As it increases, marl is formed.
- Marbled. Relatively dense limestones of light or gray-blue color. May also contain fossils.
Based on their application, limestones are divided into construction (cladding) and fluxing limestones. The former are used in the construction of houses and facing work. The second is in metallurgical production.
Where is limestone mined?
This breed has an almost ubiquitous distribution, and the reserves of this mineral are enormous and will never be exhausted. It is mined in open pits. Heavy equipment is used for this purpose; the formation blasting method can be used.
There are a large number of deposits in the center of the European part of Russia: Moscow, Tula, Voronezh, Belgorod and other regions. Large limestone deposits are being developed in eastern Ukraine (Donbass). There are deposits of rare limestones in Crimea.
LIMESTONE, sedimentary rocks formed at the bottom of a warm sea from the remains of living creatures that lived in the water. At least 50% of limestone consists of calcite (CaCO3). There are many different types: Carboniferous limestone, CHALKET, oolitic and... ... Scientific and technical encyclopedic dictionary
Limestone- – sedimentary rock, chemical composition – calcium carbonate CaCo3; used as a facing material (for example, in plinths), for the manufacture of cornice slabs, blocks for bases, intermediate blocks in column trunks,... ... Encyclopedia of terms, definitions and explanations of building materials
See Lime, limestone... Brockhaus Biblical Encyclopedia
See Limestones. Geological Dictionary: in 2 volumes. M.: Nedra. Edited by K. N. Paffengoltz et al. 1978. Limestone ... Geological encyclopedia
Calcilutite, zoolite, madreporite, shell rock, chalk, phytolite Dictionary of Russian synonyms. limestone noun, number of synonyms: 16 anthraconine (2) ... Dictionary of synonyms
LIMESTONE, a sedimentary rock containing carbonates (mainly calcite) as the main minerals, as well as carbonated organic remains (shells, algae, corals, etc.), clay and sand particles... Modern encyclopedia
Sedimentary rock consisting mainly of calcite, rarely of aragonite; often with an admixture of dolomite, clay and sand particles. Limestones often contain the remains of calcareous skeletons of fossil organisms. Used in metallurgy... Big Encyclopedic Dictionary
LIMESTONE, limestone, man. (mineral). Sedimentary rock containing lime. Limestones include marble, gypsum, and chalk. Dictionary Ushakova. D.N. Ushakov. 1935 1940 ... Ushakov's Explanatory Dictionary
LIMESTONE, ah, husband. Sedimentary rock consisting mainly of... from lime spar. | adj. limestone, oh, oh. Ozhegov's explanatory dictionary. S.I. Ozhegov, N.Yu. Shvedova. 1949 1992 … Ozhegov's Explanatory Dictionary
limestone- Mineral rock, rep. CaCO exists in the form of three polymorphs: calcite, aragonite and vaterite. Calcite has a bcc lattice (similar to NaCl), compressed along one of the diagonals of the cube to 76.66% of the original. length. Crystallic... ... Technical Translator's Guide
limestone- A white or light gray sedimentary rock consisting mainly of calcite or calcite skeletal remains of organisms... Dictionary of Geography
Books
- , N. Andrusov, Reproduced in the original author's spelling of the 1890 edition (St. Petersburg publishing house). IN… Category: Business planning Publisher: YOYO Media, Manufacturer: Yoyo Media,
- Kerch limestone and its fauna, N. Andrusov, Reproduced in the original author’s spelling of the 1890 edition (St. Petersburg publishing house)… Category: Geosciences, Geography, Environment, Planning Series: Publisher:
, a clastic rock of organic, less often chemogenic origin, consisting predominantly of calcium carbonate (CaCO 3) in the form of calcite crystals of various sizes.
Limestone, consisting mainly of shells of marine animals and their fragments, is called shell rock. In addition, there are nummulitic, bryozoan and marble-like limestones - massively layered and thin-layered. During metamorphism, limestone recrystallizes and forms marble.
Deposits [ | ]
Limestone is a widespread sedimentary rock formed with the participation of living organisms in sea basins. This is a monomineral rock consisting of calcite with impurities. The name of a variety of limestone reflects the presence in it of remains of rock-forming organisms, area of distribution, structure (for example, oolitic limestones), impurities (ferruginous), nature of occurrence (limestone), geological age (Triassic).
Entire mountain ranges in the Alps and Crimea are made of limestone, and it is also widespread in other places. Limestone has no shine, it is usually light gray in color, but can be white or dark, almost black; bluish, yellowish or pink, depending on the composition of the impurities. The remains of ancient animals are found in the limestone.
In Russia, limestones are common in the central regions of the European part, and are also common in the Caucasus, the Urals and Siberia.
The deposits of the Russian Platform are widely known, the limestones of which were traditionally used for construction and exterior decoration of buildings. Today, the raw material base of these limestones, including the white limestones of the Myachkovsky horizon, is very limited.
One of the most promising [ ] limestone deposits are considered to have been discovered in 2015 (Orenburg region), where currently [ When?] industrial mining of Sarmat limestone is underway. The deposit supplies limestone with high quality indicators, has large reserves and shallow beds [ ] . The physical and chemical properties of limestone from the Zhdanovsky deposit are given below:
Application [ | ]
Limestone is widely used as a building material, and fine-grained varieties are used to create sculptures.
Firing limestone produces quicklime, an ancient binding material still used in construction. One of the main building materials obtained from limestone is crushed limestone, which is widely used in road construction and in the production of concrete. In metallurgy, limestone is used as a flux. Limestone is used in the chemical and food industries: in the production of soda, mineral fertilizers, glass, sugar, and paper.
Shell rock [ | ]
Shell rock (shell rock, shell) - building material of natural origin, known since ancient times and popular in the southern regions of Russia, as well as the coastal regions of Ukraine and Kazakhstan.
Shell rock is used:
- in housing construction: laying external walls and erecting internal partitions;
- at business facilities: construction of basements, garages, fences, etc.;
- in landscape design: retaining walls, fountains, grottoes;
- for facing work: in the form of tiles with mandatory preliminary hydrophobization and polishing.
The most common grades in terms of strength: M35, M25, M15.
