Properties of limestone. Mountain breed limestone

Limestone, chalk - basic raw materials for the production of lime, portland cement, clay cement, an important component of glass and ceramic mixtures. Limestone and chalk consist mainly of calcite mineral - and differ only in density. Limestone is a solid and dense sedimentary breed. The technology of building and silicate materials from carbonate limestone breeds occupy the most important place. Limestones have sedimentary origins and locate among the breeds of all groups and geochronology systems. In the South Kazakhstan region, they are particularly widely represented by Paleozoa, top chalk and neogen. The chalk is a sedimentary fine-grained, weak-cemented and loose breed consisting of the smallest skeletal parts and the shells of the simplest organisms. The quality of carbonate raw materials depends on its structure, quantity and type of impurities, as well as their distribution in the mass. The highest requirements are presented to carbonate raw materials for glass production. In limestone and vele for varietal dishes allowed not more than 0.03%, for window glass - 0.2%.

Limestone must comply with the requirements of GOST 23671-79, specified in Table 13.

Table 13. Technical requirements for limestone

Sustubinskoye Limestone deposit

Sustubinskoye limestone deposit is located in the Tulikubassky district. The chemical composition of the limestones of the Sostyubinskoye deposit is provided in Table 14.

Table 14 Chemical composition of limestone Sostyubinskoye field

Volumetric weight of limestone-2-3 (2.55) g?, Density - 2.69-2.7 (2.7) g?, Water absorption -2-3 (2.5)%, specific weight -1,62 ?, volume-bulk weight-1300 kg?, porosity-0.6%, the content of clay particles -1% and humidity is -0.1%. Limestones consist of 98% of calcite, in the amount of about 2 there are chalcedony, quartz, less often dolomite and residues of microorganisms. The reserves of limestone SAS-Tuby deposit in categories A + B + make up about 70 million tons.

Badamskoye deposits of limestone is located in the Ordabasynsky district, in 4km south-west of g? D Art. Badam. Fields of 6500? 800m made by limestones of the Upper Devon - Lower Carbon. Limestones dark gray, fine-crystal. The fall in the layers at the angles of 45-60 in the south-east, the power is -85m.

Kasyghurto deposit of limenikov

The Kazigurt deposit is located in the Tolebiy district. The reserves of limestone suitable for the cement industry are taken into account by Gosbalance on 01.01.96 and amount to categories A + B + about 270 million, including in about 30 million, more than 110 million, - about 130 million, more than 450 million ..

The reserves of limestone used as a building stone are consisting of categories A + B + more than 11 million to more than 55 million.

Externally lime and chalk are very similar. Both whites leave a trace on the dark surface, they can be swap clothing and hands. This, perhaps, their similarity and ends. The further differences are followed, and above all - in the chemical composition of these materials and in the field of their application. Let's consider in more detail what the lime differs from the chalk and that they have in common.

What they consist of

The chalk is a sedimentary breed and consists mainly from the remains of the ancient marine simplest, containing calcium carbonate. Millions of years of part of the bodies of these organisms accumulated in some places of our planet and eventually formed rich deposits and even whole rocky arrays. The chalk cliffs of the coast of the Northern and Baltic Seas are well known, as well as the Para de Calai Strait in Northern France, Denmark and South England. Interestingly, the most old of the famous names of England - Albion - comes from ancient Industo-European albho - white. And the basis for this name of the island was precisely white chalk rocks that are in a narrow place separating England from mainland Europe.

The difference between the chalk is that under this term a whole group of chemical compounds and mixtures, which are common to calcium in the composition of calcium. The "basic" lime is calcium oxide (CAO), which is obtained by firing some sedimentary rocks, primarily chalk and limestone (Caco 3, or calcium carbonate). Such a lime is called Negareva. There are some more varieties of lime:

• harated (Ca (OH) 2), which is obtained as a result of the interaction of negated lime with water;
• chlorine (CA (CL) OCL) - in the surprise "Chlork", obtained by a chemical reaction in which hawed lime and chlorine are involved;
• natowers, which is a mixture of two chemical compounds - sodium hydroxide (NaOH) and hazed lime.

Comparison

The areas of application of chalk and lime (it will be more correct to say - the famous, since there are several of them) differently. We all know the student chalk, which is widely used in school, but it is only one of his "specialties". In addition, he found an application in the production of high-quality coated paper, as well as when creating some rubber varieties and in the food industry. Often chalk plays the role of filler in various compositions - from paint products to polymers (polypropylene and polyethylene). And finally, he relates him to a hawed lime that both of these material are suitable for whitening trees, borders, fences, and so on.

Different types of lime are distinguished rather strongly, therefore their applications also take apart far from each other. Negained lime is used in construction and to obtain some other species. Hairted lime, except bliss, is needed in the production of building materials, limescale agricultural, skin toss. In dentistry - for disinfection of a dental channel, and in electrical engineering - as a composition, which allows to reduce (where necessary) the soil resistance during the grounding device. And finally, even in the food industry, harated lime is known as the food additive E 526.

Two main "specialties" of chlorine lime - disinfection and whitening of fabrics. If it copes out from the first one, in the second case, it is necessary to be careful and use only the compositions made by the industrial method, since with a high concentration of the composition he simply "pro-" any tissue. And the main "calling" of the natron lime is the absorption of carbon dioxide air. This property is indispensable in gas masks and diving equipment. It was even used for a similar purpose in the first spacecraft, but later moved to more efficient compositions.

Table

Now you can give a clear answer to the question, what is the difference between lime and chalk. The table below summarizes that these materials are in common and what they differ.

The second major raw material for the production of soda is the limestone or chalk. More preferred raw materials are limestone. The disadvantage of the chalk is his porous breed, it easily absorbs moisture, violating the normal course of roasting it in limestone furnaces.

It is usually considered that the best raw material is a limestone with a content from 92% CaCO 3, moisture from 1 to 5% and a minimum amount of silicates, although retreats from these conditions are possible, depending on the nature of industries. Work on one thing causes additional fuel costs or pre-dry it, or in the furnace itself, as well as the dilution of the furnace gas (CO 2 content). Work on one thing, due to its high humidity is not economical, and in connection with this prepare for limestone limestone furnaces and chalk in the proportion of approximately 1: 1. The presence of such a proportion leads the work of the furnace to normal conditions as in the sense of fuel consumption and the concentration of the resulting furnace gas. Basic requirements for practicing in terms of sizes of chalk or limestone, it is to have a material in slices of about 60-150 mm. The percentage of Caco 3 in the chalk should not be below 80, with the champs with the lower content of Caco 3, it is no longer profitable. It is also necessary to have a certain and minimum percentage of impurities, especially SiO 2, thanks to which low-melting silicates are formed in the furnaces (the oven "flows"), and which at the bottom of the furnace freezes into large pieces - the so-called "goat". The percentage of moisture in the chalk should be no higher than 5%, in order not to have a dilution of the furnace gas, as well as not to spend the excessive amount of fuel for drying it.

The mining of limestone and chalk is conducted in the careers by open developments. With a thin layer of the upper rustling breeds, mine developments do not apply. Removal of the upper apparent layers and direct mining of limestone and chalk are produced using excavators.

There are several ledges along the stretch of the layers, in which small cylindrical holes are blurred - the sheets where the explosive is laying. The blurred fragmented breed is shipped with excavators in the trolley and dismay on the crushing and sorting installation that is at careers. Slices with dimensions 40-120 mm are separated and, depending on the distance from the career to the factory, is transported either through a cable suspension or by rail. In the first case, the trolleys with carbonate raw materials are served directly to the limestone furnaces, in the second case, limestone or chalk comes first to the warehouse, from where the suspension trips or an elevator are transported to the furnace. Slices having a size of less than 40 mm are a waste that can be used for other purposes, for example, on construction work, in the production of cement, in the metallurgical industry, or to obtain lime in specially allocated for firing chokes.

a piece of chalk - This is not only familiar to the whole subject from school times, but also witness epochs that have passed millions of years ago.

Most of the composition of the chalk form calcium deposits of the shelter of prehistoric microorganisms and the simplest plants. Chalk deposits, including processed, are used today in various fields - from the production of paints and food additives to cosmetics.

How did the chalk occurred?

a piece of chalk It is a natural material and is mined as mineral resources. It is based on its calcium deposits formed from the remnants of ancient earthly organisms.

In the production of chalk and small-containing products, the chalk has already been used.

Natural chalk deposits often contain various undesirable impurities - stones, sand and a variety of mineral particles. Therefore, the chalk extracted at the deposits break and mix with water in such a way as to get a suspension.

At the same time, heavy impurities are lowered to the bottom, and light calcium particles are sent to a special tank, where they are dried after adding a special bonding substance, turning into chalk, which can be drawn.

Unprocessed chalk of chalk careers use for construction purposes to obtain lime.

We bring to your attention another article on the origin, its composition and therapeutic properties.

What is chalk and what does it consist of?

The composition of the chalk includes:

• calcium oxide - from 47 to 55%;
• carbon dioxide - up to 43%;
• silicon dioxide - no more than 6%;
• aluminum oxide - up to 4%;
• magnesium oxide - no more than 2% of the total weight of the chalk;
• also, the composition may include iron, however, its concentration usually does not exceed 0.5%.

Chalk clusters

The accumulation of chalk departments began in the so-called chalk period, covering a period of 80 million years. About 20% of the sedimentary breeds of the Earth include in their composition chalk.

Mela field:

• To the largest chalk departure The white cliffs of the Dover, the chalk caves in the French city of Champagne and the chalk cliffs of Mons Clint in Denmark.
• On Russian territory Cretaceous mountain deposits thick up to 600 meters are located south of Kharkov.
• The largest deposits of the Voronezh region - Capaniskoe, Rossoshansky and Bourning. Belgorod, allegedly, received his name thanks to local chalk departments.

Formation of chalk

The formation and accumulation of limestone deposits occurred more than eighty millions of years.

Foraminifera - Unicellular organisms whose shells served as the basis for the formation of today's chalk deposits. After the death of these simplest, their Panciri fell to the bottom of the ocean, creating foraminiferous limestone.

These formations, along with the remnants of single-celled plants, kokkolitoforide are part of today's chalk clusters. Compressed under pressure water, the remains of the kokkolitoforide and the shells of ancient mollusks Millions of years were supplemented by skeletal remains of fish and animals.

Despite the fact that in 1953, scientists declared the advantageous role of plants in the formation of limestone rocks, there are still an opinion on the majority of the Foraminifera.

Structure

The composition of chalk deposits includes:

• Fragments of skeletons - Approximately 10%. These are the remains of not only the simplest, but also large multicellular animals.
• Shells of ancient mollusks - 10 %. Among them were animals with limestone shells - Foraminifera.
• Lime-based algae particles - no more than 40%. Most of the limestone deposits, contrary to popular belief, was formed from the remnants of the simplest plants - kokkolitoforide, and not due to the sinks of the foraminifera. Kokkolitoforids were not extinct, they perfectly feel at the expanses of the World Ocean today, taking part in the exchange of carbon between the ocean and the atmosphere.
• Ground crystalline calcite - no more than 50%. These are natural mineral formations of complex origin.
• Insoluble silicates - until 3%. These are minerals of geological origin - sand, fragments of rocks, entered into chalk deposits by wind and water. Mel

A large influence on the properties of the chalk has humidity affecting its strength and plasticity. Improving humidity leads to deformation, whereas in a dry environment chalk can crumble even from minor pressure.

Saturated moisture breed sticks to construction tools. That is why construction work using calcium carbonate is carried out in countries with hot and arid climate. An excellent example of the ancient construction from limestone is the Egyptian pyramid of Heops (Hufu).

At a minus temperature of the breed, the breed is prone to decay into fragments of several millimeters.

Cost of chalk

The price of chalk will depend primarily from his type (processing) and purpose:

• for drawing on asphalt will cost no more 200-400 rubles for packaging.
• White chalks Without dyes will cost about 100 rubles .
• Farm chalk I buy large parties by shipping it in a few tons. The cost of each ton of ground chalk is 3000-5000 rubles.
• Price for food chalkused in medicine and food additives (E-170) - from 40 to 300 rubles For 100 grams. In medicine also used a stone).

Application of chalk

Today chalk is a fairly widespread material for various areas of production.

So, chalk applies in the following areas:

1. Cretaceous paintsused for interior decoration during construction and repair work.
2. Chalk is part of cement mixtures, providing them with softness and elasticity.
3. Ground natural chalk Actively used for glass production.
4. Chalk is part of the farm feed And used for soil fertilizer.
5. Chalk is the basis for cosmetics - lipstick, tonal cream, powder, etc. It is the chalk in the composition of a tonal cream absorbs excess fat and protects the skin from glitter.
6. Applied chalk and for domestic purposes As absorbing and bleaching components.
7. Powder and Paste Production It is also not necessary without the use of chalk.
8. In the production of paper and cardboard products The fine (crushed) chalk is used as a filler and paper bleach. The chalk treated with stearic acid has hydrophobic properties. It is also used in the paper industry. The content of chalk in paper improves the quality of the print and reduces the likelihood of wear of the printed equipment.
9. Not so long ago chalk used to apply markup on the game field. Silence lifting in the air after entering the ball on the line, it was easy to see. Today, instead of the chalk, titanium dioxide is used.
10. To remove sweat And reducing the risk of sliding chalk is used in sports such as weightlifting, gymnastics and climbing and today.

Can I have chalk?

The lack of calcium and other useful trace elements can lead to the desire of the use of chalk in food. During pregnancy, with anemia, some people have a strong traction for eating chalk, so the question of the safety of this mineral for the body arises from many.

Of course, one or two small pieces of pure chalk will not bring strong harm to the body. However, it is necessary to remember that the chalk without impurities is unavailable in free sale and it is practically not possible to get it possible, except in the pharmacy in the form of calcium gluconate. In the most common product - "School chalk", in production, add glue and various dyes, toxic to the body.

The use of chalk in large quantities can cause vessel limeting, the formation of kidney stones and provoke problems with the digestive tract.

In addition to the destructive effects of impurities that are part of the construction and chancellor chalk, it is characterized by oxidation when interacting with gastric juice, turning it into a harmful chemical reagent.

What if you want to eat chalk?

The desire to eat chalk in food is often a signal about a lack of calcium in the body. The causes of its deficiency may be monotonous nutrition, long stressful states, weakening the body after severe diseases and pregnancy.

Considering that during pregnancy, calcium is the basis for the formation of the nervous and skeletal system of the child, the lack of this mineral must be replenished. In this case, the diversity of the diet is not able to fully solve the problem, so doctors strongly recommend during pregnancy to take special vitamin complexes.

Due to the fact that the fetal nervous tube is formed in the early deadlines, in order to minimize the risks of incorrect development, it is necessary to start taking vitamins even during pregnancy planning. Anemia and calcium deficiency in the body often appear with abundant and long monthly.

With symptoms of a strong calcium effect (seizures, noticeable deterioration and pale skin and hair) You can take calcium tablets gluconate. In contrast to the stationery and other types of industrial chalk, they are safe, however, with long-term uses can lead to constipation.

As a rule, the traction for eating the chalk ends after expanding the diet and the inclusion of dairy products, chicken eggs and fresh greenery.

In some cases, the desire for eating inedible and small substances may be a sign of mental disorder. The consequence of the use of incredible objects is intestinal obstruction and food deficiencies.

To the question of what the difference between lime, plaster and chalk? All foundation CA. I know it. Posted by the author harvesting The best answer is Lime, conditionally combined by general term firing products (and subsequent processing) limestone, chalk and other carbonate rocks. Most often called "I. »Combinate I. Negashina CAO (see calcium oxide) and the product of its interaction with water - I. Gashenaya Ca (OH) 2 (see calcium hydroxide). I. Widely used in construction, metallurgy, chemical industry, in the production of sugar, paper, glass, etc., as well as in agriculture, for water purification, etc. Other species I. - Lime Nat and chlorine lime.
I. Construction serves as a binding material; contains up to 95% of CAO; It turns out the firing of natural calcium-magnesium carbonates in mine, rotating and other furnaces (at a temperature of 1100-1300 ° C). I. - one of the oldest binding materials. It was used in a mixture with sand and water for another 3000-2500 years BC. e. For fastening stones and bricks in various facilities, as well as for the preparation of plaster solutions and colorful compositions. Such a mixture under the action of carbon dioxide air is gradually hardening due to the formation of crystalline calcium carbonate and evaporation of water:
Ca (OH) 2 + CO2 \u003d Caco3 + H2O.
Gypsum (from Greek. Gýpsos - chalk, lime), mineral, water sulfur calcium salt Caso4 · 2H2O; Pure form contains 32.56% SAO, 46.51% SO3 and 20.93% H2O. Crystallizes in a monoclinic system. The structure of the crystal lattice of G. refers to the type of layered. Double layers consist of tetrahedra associated with calcium. Plastic crystals, columnar (single or resulting in the form of twins - t. N. Swallow tail, see fig.), Needle and fibrous. It is found primarily in the form of continuous grainy (alabaster) and fibrous (selenites) masses, as well as various crystal groups (gypsum flowers, etc.). Clean the city is blunt and transparent, if there are impurities, it has grayish, yellowish, pinkish, brown and others. Coloring. Hardness by mineralogical scale 1.5; Density of 2300 kg / m3, solubility 2.05 g / l at 20 ° C (the largest - between 32 and 41 ° C). Precipitated from aqueous solutions rich in sulphate salts (while drying the sea lagoon and salty lakes). G. falls at a relatively small saline, when it is raised, instead of the city, anhydrous sulfate calcium sulfate is to fall out - anhydrite, and then salt.
Chalk, weakly semplarified, stitching, fine-grained variety of carbonate rocks, consisting mainly of calcium carbonate of natural origin or obtained by artificial way. Natural M. is composed mainly by calcite skeletal particles of microorganisms - kokkolitoforide lime algae (70-90%) and Cornojek - Foraminifera (1-20%). Occasionally in M. Mollusk sinks, mshanok skeletons, sea cheers, lilies, silica sponges, corals are found. Chemical composition M. (in%): 50-55 CAO; 0.2-0.3 mgo; 0.5-6.0 SiO2; 0.2-4.0 Al2O3; 0.02-0.7 Fe2O3 + FEO; 40-43 CO2. Mineral composition (in%): 90-99 calcite; 1-8 clay minerals (montmorillonitis, hydroslides and kaolinitis); 0.01-0.1 pyrite; 0.1-0.5 glauconitis; 0.2-6 quartz; 0.01-7.0 opal; 0.01-0.50 Zeolita Gaylanditis; 0.01 Barita. Partition content< 0,01 мм обычно свыше 90%. Плотность 2,70-2,72 г/см3; объёмная масса скелета 1,42-1,56 г/см; пористость 45-50%; естественная влажность 30-33%; сопротивление сжатию влажного М. 1-2 Мн/м2 (10-20 кгс/см2), сухого 4-5 Мн/м2 (40-50 кгс/см2). В М. иногда рассеяны конкреции кремня, пирита и фосфорита. М. представляет собой полузатвердевший морской ил, отлагавшийся на глубине 30-500 м и более. Широко распространён в природе. Приурочен в основном к верхнемеловым и нижнепалеогеновым отложениям.