Properties and uses of talc. What is talcum powder? Applications, harm Talc melting point

05.09.2021

Talc- a mineral with the formula Mg 3 Si 4 O 10 (OH) 2. Synonyms: agalite (fine-fibered), steatite, wen (dense, massive). It is a friable powder of white (occasionally green) color, greasy to the touch. The quality of talc is determined by its whiteness. For industrial purposes, ground talc, microtalc, etc. are used. It should be noted that talc is a mineral that is almost insoluble in water and acids. The necessary conditions for the formation of talc are a temperature of about 400 ° C, a sufficient amount of water (after the transformation of minerals from rocks rich in iron and magnesium).

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STRUCTURE

The mineral talc has a crystalline (most often rhombic) structure. In nature, it is found in the form of sheet granular layers. It is a secondary mineral that is formed when magnesium silicates that do not contain aluminum (Al) change their chemical composition.

The crystal lattice of talc is formed by a layer of magnesium oxide, framed by two layers of non-polar tetraers of quartz and oxygen. The outer surface of the flakes does not contain any hydroxyl groups or active ions, which determines the high chemical stability and hydrophobicity of talc. Three-layer talc crystals, possessing a very strong internal bond, are themselves very weakly bonded to each other.

PROPERTIES

Talc is a recognized standard for the softness of natural materials. Color from light apple-green to white and silvery-white, sometimes yellowish. The shine is oily, pearlescent on the cleavage planes. Cleavage is very perfect. Translucent at the edges, transparent in thin leaves. Cleavage is very perfect along (001). Hardness 1 (minimum) on the Mohs scale. Greasy to the touch. Whitens under the blowpipe, breaks down into small sheets; melts with difficulty, forming white enamel at the edges.

MORPHOLOGY

Depending on the structure and mineral additives, some types of talc have their own names. So, minnesoaite is talc, in which magnesium is isomorphically replaced by iron. Has a brownish color. Willemseite - magnesium in the formula of the mineral is isomorphically replaced by nickel (the color of the stone is green, blue).

A very dense, massive talcum powder is called steatite or acne. Less common is talc, which is composed of long, matted-fibrous, parallel-fibrous, asbestos-like crystals. It is called agalite.

There are also very beautiful varieties of talcum aggregate - dense, white and translucent, which tolerate stone cutting and polishing well. They are called noble talc.

In deposits, talc is found together with chlorite, clinochlor, serpentinite, tremolite, and other minerals of the pyroxene and amphibole groups. can form aggregates in a mixture with chlorite (talcochlorite).

ORIGIN

Talc is formed by the interaction of dolomite and hot spring water. Talc stones of various impurity composition are a consequence of the reactions of silicic decomposition of magnesian rocks.

Talc deposits are ubiquitous. However, only in Brazil there are large (up to 5 cm) talc crystals covered with a quartz crust. The USA remains the champion in the industrial extraction of talc for many years. Canada, France, Russia, the countries of the Far East are famous for the development of high-quality talc.

In Russia, the Shabrovskoe talc-magnesite and Miass talcite deposits are being developed in the Middle Urals, the Onotskoe deposit of steatite (solid) talc (Eastern Sayan); revealed the West Baikal talconiferous province. Abroad, large deposits are known in Canada (Meydock), the USA (Governor), France (Lusenac), etc.

APPLICATION

This mineral has long and firmly entered various spheres of human activity and life. Since the end of the nineteenth century, it has been used as a powder with which rubber, rubber, plastic technical products are coated so that they do not stick together when they come into contact. In the sex industry, it is used to store all kinds of toys by surface treatment with talcum-based powders. In the notorious "magic practice" talc was used to prepare potions, with the help of which, as some believed, you can restore youth and beauty; these were various creams and ointments that acted on the skin as cosmetic products, but nothing more.

Since about the same time, finely ground talcum powder has been used as a baby powder. This mineral can be decomposed in the human stomach and be a source of magnesium and calcium (the drug calcium gluconate, food supplements, dietary supplements is used in preparations).

Talc is used as an additive and filler in foods. It is called the E553b food additive by the European Standards Organizations in the food industry.

Talc is a filler for tablets, paper pulp, varnishes and paints, ceramics, cosmetic products, insulators. This mineral is even added to engine oils as an additive, which increases the life of engines.

An important area of application is ceramics (especially radio-insulating).

Talc (eng. Talc) - Mg 3 Si 4 O 10 (OH) 2

CLASSIFICATION

Strunz (8th Edition)	8 / H.09-40
Nickel-Strunz (10th Edition)	9.EC.05
Dana (8th Edition)	71.2.1.3
Hey's CIM Ref.	14.4.9

What is talcum powder? Most people know it as a white powder, which is widely used in cosmetics. The mineral has the ability to absorb moisture, oils and have an astringent effect on human skin. It is an inert ingredient, i.e. does not enter into chemical reactions when ingested or on the skin. People began to use its positive properties since the days of Ancient Egypt.

Talc has the ability to absorb moisture, oils and have an astringent effect on human skin.

Talc is a mineral that is widespread in nature and is of great industrial importance. It is also known as the softest mineral. What is talc and what is its chemical composition? It contains silicon, magnesium, oxygen and hydrogen. The talc formula is expressed as Mg3 Si4 O10 (OH) 2.

Talc is a mineral that is widespread in nature and is of great industrial importance.

Talc is a translucent green, white, gray, brown or colorless mineral. Sometimes there are other shades of stone, such as red or burgundy. It has a leafy structure, like mica. The sheets are held together only by van der Waltz bonds and slide easily relative to each other. This makes talcum the softest mineral. It is greasy and soapy to the touch, which allows it to be used as a high-temperature lubricant (melting point is about 160 ° C). When heated, it becomes more solid, has a weak electrical conductivity.

Most of the talcum powder is produced in China, the United States and Japan. In Russia, deposits are located in the Urals and Siberia. The quality of the mineral depends on the whiteness of the crystals. During the extraction process, they try to avoid contamination from other rocks, which can have a negative effect on the color of the product. Impurities are removed by froth flotation or mechanical treatment. The mills perform crushing to the sizes required by the customers.

Gallery: talc stone (34 photos)

Steatite is a type of talc

Talc is found in many rocks. Steatite is a massive variety of metamorphic origin. Another name is soapstone. It has been mined for thousands of years. They made dishes from it that were not afraid of fire and slowly gave off heat. The rock consists mainly of talc with various amounts of other minerals (chlorite, magnesite). The color of steatite is gray, bluish, green, brown or variegated. Since its main component is talc, it has properties similar to it. This makes steatite a valuable material for many applications. Physical properties include:

softness and ability to cut easily;
high density and lack of porosity;
heat resistance and high thermal conductivity;
the ability to absorb moisture;
resistance to alkalis and acids.

Mineral and chemical compositions are not constant, which is why its physical properties can vary in different minerals and even within the same rock. It depends on the starting material, temperature conditions and the magnitude of the pressure.

Where is talcum powder obtained (video)

The level of metamorphism often determines the steatite graininess and hardness.

The special properties of the rock make it possible to widely use steatite in many areas:

manufacture of countertops and sinks;
creation of decorative carvings;
construction of stoves and fireplaces;
tableware making;
use as a building and finishing material;
molds for metal casting;
production of marker pencils.

Due to its properties, steatite stone is used for medical purposes as a natural heating pad, since it can store heat for a long time.

How talc is used

Everyone knows what talc is, but few people know about its widespread use. It finds applications in medicine, pharmaceutical, textile and paint and varnish industries, as well as in the cosmetics industry. Talc application:

Rubber and plastic coating for medical and technical products to prevent sticking during storage. Use in everyday life to eliminate friction of contacting surfaces (in the chamber of a bicycle tire, in rubber gloves, shoes).
Application in the production of plastics and ceramics. Usually acts as a filler, while increasing the rigidity of products, increasing their heat resistance and reducing shrinkage.
Talc is a powder that is used on the skin of babies from their first birthday. In addition to this mineral, it also contains zinc oxide and starch, which enhance the beneficial properties of the product.
Talcum powder is used as a filler in paints. It facilitates their application to the surface and at the same time serves as a bleach for light colors.
Used as an additive in papermaking, it makes paper smoother, brighter and whiter. In addition, talcum powder improves the ability of newsprint to absorb ink.
Talc's oil and moisture adsorption properties allow it to be used as a powder base in many cosmetic products, providing the desired texture and facilitating application to the skin.
In medicine, talc is used as a filler in tablets. It prevents them from caking. It is included in dietary supplements as a source of magnesium and silicon.
Talc is an additive in the food industry. It is used as a coating for candies and chewing gums, thereby preventing them from sticking to the wrapper. Also used for polishing white rice.

How to wear stones (video)

This mineral is an irreplaceable and safe component in the manufacture of many products and preparations.

Attention, only TODAY!

/ mineral Talc

Talc is a common mineral, silicate, pyrophyllite-talc group.

Varieties:

Agalite (fine fiber talc),
Noble talc (transparent light talc),
Willemseite (nickel talc),
Minnesotaite (talc iron),
Steatite (wen) (dense massive talc)

For the first time, a description of the stone under the specified name was found back in 1546. Talc was used by George Agricola, the great scientist of the Renaissance. He used the name "talk", describing the properties of the mineral and calling it pure and white. Even then, it was used when carrying out stone-cutting work, but only in some compounds and varieties that could be found in descriptions under the designations "soap stones", "wen", "only chlorite" and "steatite".

Origin

The origin of talc is associated with metamorphism. In this case, both thermometamorphism and hydrothermal processes can be involved (hydrothermal-vein - when filling voids and hydrothermal-metasomatic when replacing). Talc most often occurs during hydrothermal alteration of ultrabasic rocks after serpentinization. Formed during metamorphism over dolomites and clays.
Talc is a rock-forming mineral of talc shale and listvenite.

Special properties: talc - acid-resistant; greasy to the touch; flexible but not elastic.

Place of Birth

Brumado, Bahia, Brazil - record talc crystals (up to 4-5 cm!) Coated with quartz // see. Min. Record: 1) 1987, 9, 204 2) 1992, 23, 274, 276

Talc is a common mineral found in Antarctica and the mid-ocean ridge of the Atlantic Ocean; in Australia, Austria, Algeria, Argentina, Afghanistan, Bulgaria, Bolivia, Brazil, Burkina Faso, Bhutan, Great Britain, Hungary, Germany, Greenland, Greece, Zimbabwe, Indonesia, Iran, Spain, Italy, Kazakhstan, Cameroon, Canada, Colombia , both Koreas, Cuba, Madagascar, Mexico, Mongolia, Namibia, Norway, Oman, Pakistan, Paraguay, Peru, Poland, Portugal, Saudi Arabia, Slovaks, USA, Turkey, Chile, Switzerland, Sweden, South Africa, Japan and other countries ...

Practical value

Talc is used for the manufacture of refractory materials, in metallurgy, in the textile, paper and chemical industries, in medicine.
Steatite is used in the manufacture of various handicrafts. Powder made from talcum powder or on its basis has been widely used from ancient times to this day as a powder for the skin in medicine (the well-known baby powder is pure talc, but it has passed the process of screening out ferruginous rocks), as well as in everyday life to prevent adhesion and friction of contacting surfaces ( in rubber gloves and other products, in shoes, etc.). It is used as a filler in rubber, paper, paint and varnish and other industries (in medical, perfumery and cosmetic). In ceramics (especially radio-insulating). Registered as food additive E553b in the food industry. It is harmless and also not absorbed by the body. In the notorious "magic practice", talc was used to prepare potions that some believed could bring back youth and beauty; these were various creams and ointments that acted on the skin as cosmetic products, but nothing more.

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Mineral properties

Color	White, greenish, yellow, pinkish, brownish, gray

Line color	White

Precious stone	according to the legislation of the Russian Federation

origin of name	From Persian talc to Arabic talq, it is pure because of the color and properties of its powder.

Opening year	known since ancient times

IMA status	valid, described for the first time before 1959 (before IMA)

Chemical formula	Mg 3 [OH] 2, or MgO · 4SiO 2 · H 2 O

Shine	fatty pearl dim

Transparency	transparent translucent shines through opaque

Cleavage	very perfect very perfect by (001)

Break	uneven splinter mica-like

Hardness	1

Thermal properties	Under p.tr. turns white, disintegrates into small sheets; melts with difficulty, forming white enamel at the edges.

Typical impurities	Ni, Fe, Al, Ca, Na, H2O

Strunz (8th Edition)	8 / H.09-40

Hey "s CIM Ref.	14.4.9

Dana (8th Edition)	71.2.1.3

Molecular weight	379.27

Cell parameters	a = 5.29Å, b = 9.173Å, c = 9.46Å α = 90.46 °, β = 98.68 °, γ = 90.09 °

Attitude	a: b: c = 0.577: 1: 1.031

Formula units (Z)	2

Unit cell volume	V 453.77 Å³

Point group	1 - Pinacoidal

Space group	P1

Density (calculated)	2.78

Density (measured)	2.58 - 2.83

Pleochroism	weak

Dispersion of optical axes	r> v tangible

Refractive indices	nα = 1.538 - 1.550 nβ = 1.589 - 1.594 nγ = 1.589 - 1.600

Maximum birefringence	δ = 0.051

A type	biaxial (-)

Optical relief	moderate

Allocation form	Tabular crystals; leafy, radiant, scaly and fine-grained aggregates; solid masses. Sometimes talc forms dense cryptocrystalline masses (steatite); pseudomorphs on tremolite, enstatite, spinel.

Classes on taxonomy of the USSR	Silicates

Talc is the most abundant material on earth and this soft mineral is used in cosmetology and many industries. It occupies one of the first "honorable" places on the Mohs scale, which clearly indicates its softness, although coarse-grained talc, which is commonly called steatite, is also found in nature. And it is he who takes on the function of an ornamental stone.

Description of the mineral

Talc has been known to people for a long time, and George Agricola, the great scientist of the Renaissance, was one of the first to use it. It was he who gave the mineral the name that people use to this day. Talc is a crystal-like substance that, due to its physicochemical characteristics, seems oily to the touch. This feature is explained by the looseness of the mineral, and if you wet it, it will be simply impossible to hold a piece of talc in your hands, because it was not without reason that it was called a “soapstone” in ancient times.

"Real" talc has a pure white color, but if it contains impurities of metals, then the color palette expands significantly. For example, the presence of iron, aluminum, chromium, manganese, nickel determines the shade of the mineral, and it can have a pinkish, yellow-golden, silver-gray, brownish color. In thin layers, an almost transparent mineral is sometimes found, very similar in appearance to mica and highly resistant to alkalis and acids. At its core, it is a secondary mineral formed as a result of changes in the chemical composition of magnesium silicates.

Deposits and production

The stone belongs to the category of the oldest, which is clearly evidenced by the finds of archaeologists on the territory of modern Egypt, where amulets and jewelry were discovered during the research. In those distant times, talc was also mined in the East, and hard greenish stones were considered one of the best imitations of jade. Now it is mined practically all over the planet, and its main deposits in the Russian Federation are concentrated in the Urals and Siberia. These deposits were found in the Trans-Baikal and Krasnoyarsk Territories.

The high-quality mineral is mined in France, Poland and some other European countries. Brazil, USA, Egypt, China - all these are territories with inexhaustible sources of talc. Some regions of Africa and South America are very rich in them, but mining is not carried out, since not a single state experiences a shortage of this kind of stone, and its reserves are practically inexhaustible. It is noteworthy that a stone with a solid structure is valued most of all.

Varieties

The appearance, structure and properties of the mineral are determined by impurities:

1. Talcochlorite. The mineral contains chlorite and talc in a 1: 1 ratio.
2. Noble talc. This is the same ornamental stone that lends itself well to processing and polishing. Appears in the form of white or translucent crystals, which are characterized by high density.

Willemseite. This mineral contains nickel and magnesium, with the former dominating the latter, which gives this stone a bluish-green hue.
Minnesotaite. The stone is brown. What gives him such a coloring? Iron, dominant over magnesium.
Agalit. It is often confused with asbestos, and the reason for this confusion lies in the similarity of the structures.
Steatite. This is the same legendary "soapstone" or as it is also called - "wen". A distinctive feature is a massive, dense structure.

Physical and chemical properties

Mg3Si4O10 (OH) 2 is the chemical formula of talc, which is essentially hydrous magnesium silicate. In some cases, silicon by nature can be replaced by aluminum or titanium, and magnesium by manganese or iron. The quantitative and qualitative composition of impurities directly depends on the deposit. Talc is formed by the transformation of some minerals, and for the "process to go", it takes time, water and constant exposure to high temperatures - about 400 degrees.

The stone can have the most bizarre shades: from white to brown, in addition, it can be translucent. Low elasticity is inherent in it, however, some varieties of the mineral bend perfectly. The mineral has low electrical and thermal conductivity, it is non-toxic, poorly soluble in acids and water. For medical and cosmetic purposes, talc is finely crushed and turned into a white powder, greasy to the touch. If necessary, the powder can be sterilized at a temperature of 160 degrees, however, this will take at least an hour.

Application in cosmetology

Women who use eyeshadow every day do not even suspect that they contain talcum powder. But it is he who allows decorative cosmetics not to crumble and adhere well to the skin. In addition, this powdery product is often incorporated into creams and other cosmetics, including powders. What does it do? Talc protects the skin and makes it soft, smooth and dry for a long time. The fact is that the mineral crushed into dust is an excellent adsorbent that literally collects sebum, sweat and chemicals, bacteria on its surface. Thus, additional protection is provided to the epidermis.

According to some scientists, this unique powder prevents the appearance and reproduction of harmful microorganisms. This is probably why it is present in the composition of baby powders. It can also be found in face masks, dry deodorants, and other products. Of course, special requirements are imposed on talc used in medicine and cosmetology: particles must be of a certain size, without impurities, foreign odors and pathogenic microflora.

Medicinal properties

Medical experts believe that talc takes on the function of an antiseptic and performs it successfully. This clearly proves the historical fact, when before the invention of antibiotics in hospitals, wounds were covered with talc, since there was simply no other alternative. And it really helped reduce the likelihood of gangrene. Yes, the powder has anti-inflammatory properties, but for it to "work", its particles must have a certain size, since too small clog the pores of the skin, which, on the contrary, often causes inflammation.

Now talcum powder is used by people with delicate skin, and besides, they are simply irreplaceable for babies. By the way, some doctors recommend using this powder internally, which you don't need to do, since such experiments can negatively affect your health. Although, at the same time, talc is present in the composition of many drugs, however, it is used as a filler, along with starch. If you manage to get whole, uncrushed stones, then they can be heated and used as a heating pad.

Benefits and harms of taklq

Talc has more benefits than harm, but still it is. This mineral is constantly undergoing research, during which scientists have found that it can be dangerous.

If you inhale mineral dust or powder for a long time, you can become a victim of a very unpleasant disease called talcosis. This ailment is inherent in people who, by occupation, deal with mineral dust on a daily basis. In addition, oncologists have put forward their own version: in certain situations, talc can act as a carcinogen and provoke the onset of cancer. It is noteworthy that this theory has not been confirmed.

Magical properties

Almost all ancient and medieval sorcerers believed that talc, crushed to a powdery state, could restore lost youth and beauty. Their "clients" piously believed in this, paying enormous sums for anti-aging ointments and creams. In part, such drugs contributed to giving the skin a more attractive appearance, but this is not the merit of magicians and witches, but talcum powder, which unwittingly became a source of enrichment for charlatans. It is noteworthy that this mineral is not used to make talismans and amulets, and besides, it does not patronize any of the zodiacal constellations.

Application

Probably, there is no industry sector in which talc is not used: this is the production of rubber products, papermaking, the production of paints and varnishes, and even the food industry. Since talc stone is endowed with unique physicochemical properties, its use is expanding significantly. For example, large minerals are sawn into slabs that are used as linings for sinks, switchboards, laboratory benches and other products. Often this material is assigned the role of a dry lubricant.

Where else can you find talc, besides pharmacies, hospitals and industrial plants? For example, in offices. The fact is that so-called talc paper is used to prepare especially important documents, which perfectly absorbs ink. In addition, progressive ateliers and sewing workshops have long switched to talc chalk instead of the usual one (it is involved in cutting fabrics). This is due to the fact that the pressed talcum powder is much easier to remove from the material, which is very important. Talcum powder can be found anywhere, for example, it is poured over plastic and rubber products in order to prevent them from sticking together, and even ordinary rubber household gloves are always powdered from the inside with this versatile powder.

Talc crystals.

It is found in additives to motor oils to increase the service life and protect the internal combustion engine. Example SuProtec / NanoProtec, Hado.

Extraction and production

During the Soviet era, the Shabrovskoe talc-magnesite deposits were developed in the Middle Urals and the Miass talcite deposits in the South Urals, the Onotskoe steatite talc deposit (Eastern Sayan), the Kiryabinskoe deposit, the city of Uchaly, produced by OOO Company Bashtalk, Pribaikalskaya talcon-bearing province.

Large deposits of talc are found in Canada (Meydock), USA (Governor), France (Lusenac).

Danger

It is possible that inhalation of talcum powder can cause talc, a benign pneumoconiosis disease, however special studies carried out by an interested party, namely the European Talcum Producers Association, have shown that talc is harmless to health.

Meanwhile, American scientists have found that the regular application of talcum powder to the female genital area significantly increases the risk of developing uterine cancer. According to the researchers, this dependence may be due to the fact that the smallest particles of talc penetrate into the internal genital organs and are fixed there for years, causing chronic inflammation. This long-lasting inflammation, in turn, creates favorable conditions for malignant degeneration of endometrial cells and the rapid growth of cancer.

Notes (edit)

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Silicates (minerals)
Magnesium minerals
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Synonyms:

See what "Talc" is in other dictionaries:

talc- talc / ... Morphemic-spelling dictionary

- (silicic magnesium) mineral, white and green. different colors shade. with a pearlescent sheen, greasy to the touch like stearin. Mixed with oil, goes to lubricate the carriage wheels; it is also used in the form of a powder to make it easier to put on boots. Dictionary… … Dictionary of foreign words of the Russian language

A; m. [German. Talk from Arab.] Layered soft mineral of white or greenish color (used in technology and medicine, usually in the form of a powder). Talc deposits. Ground t. Sprinkle talcum powder on the rubbed. Powder your hands with talcum powder (about gymnasts, weightlifters and ... encyclopedic Dictionary

A soft mineral powder that easily turns into the smallest powder. It is used in confectionery for the manufacture of molds for molds, where sugar and chocolate shells for liqueur sweets are cast, that is, that rare type of sweets, ... ... Culinary vocabulary

talc- a, m. talc it. Talk.arab. talk. A layered soft mineral of white color, usually used in the form of a powder in engineering and medicine. ALS 1. De la Gere and Gigens describe rhomboidal spar under the name talc. Severgin 1791 1 36. ... ... Historical Dictionary of Russian Gallicisms

Mineral of the subclass of layered silicates, Mg3Si4O10 (OH) 2. White, greenish. Hardness 1; density 2.6 2.8 g / cm & sup3. Varieties: dense steatite, fine-fibered agalite, noble talcum transparent light. A product of hydrothermal alteration ... ... Big Encyclopedic Dictionary

- [arab. talg] ml, Mg3 [(OH) 3 | Si4O10]. Minor substitutions of Si for Al, Ti; Mg on Fe, Mn, Al. Tricahedral layered silicate. Mon. Gab. tabular. Sp. v. owls. by (001). Agr .: scaly, leafy, dense. Colorless and with different shades ... Geological encyclopedia

TALC, talc, pl. no, husband. (Arab.). Mineral, hydrous magnesium silicate in the form of a greasy, soft, usually white powder, ex. in technology, in cosmetics and medicine. Sprinkle (rash, diaper rash) with talcum powder. Ushakov's explanatory dictionary. D.N. Ushakov ... Ushakov's Explanatory Dictionary

TALC, a (y), husband. Light soft layered mineral, cons. in technology and medicine. | adj. talcum powder, oh, oh. Ozhegov's Explanatory Dictionary. S.I. Ozhegov, N.Yu. Shvedova. 1949 1992 ... Ozhegov's Explanatory Dictionary

Steatite, agalite Dictionary of Russian synonyms. talc n., number of synonyms: 7 agalite (2) ... Synonym dictionary

Books

A set of decorative cosmetics "Beautician-Carriage" (VV 1773),. A set of children's decorative cosmetics. Completeness: 2-level cosmetic bag-carriage with a mirror, eyeshadows with sparkles (9 shades), applicator, lipsticks (2 colors), nail polish. Compound:…