Interaction of zinc and water. Chemical properties

The role of zinc in the human body

The average zinc content is 2-3 grams. Part of it accumulates in muscle and bone tissue, 20% in the skin. This microelement is found in leukocytes, red blood cells, sperm, prostate and pancreas and liver. It is part of about 400 enzymes, the most studied is carbonic anhydrase. The protein containing zinc is found in red blood cells. It breaks down carbon dioxide into carbonic acid and bicarbonate for disposal from the body. Clean carbon dioxide forms gas plugs in the bloodstream, but its derivative, carbonic acid, is water-soluble and easily decomposes under the influence of an enzyme.

Functions of zinc in the body:

• Participates in the breakdown and synthesis of carbohydrates, proteins and fats.
• It is part of hormones, antibodies, leukocytes, and improves immunity.
• Increases the regenerative abilities of the body.
• Detoxifies carbon dioxide from the body.
• Affects the formation of male sex hormones and supports prostate health.
• Participates in the metabolic processes of the thyroid gland, adrenal glands, ovaries and pituitary gland. Protects the pancreas from damage and is needed for insulin secretion.
• Promotes better absorption of vitamin E, promotes the metabolism of vitamin A.
• Has a beneficial effect on dental health: zinc is found in enzymes and bone cells.
• Relieves inflammation, improves skin condition.
• Promotes normalization of the structure of ribosomes, ribonucleic and deoxyribonucleic acids (RNA and DNA), participates in cell division.
• During pregnancy, the intake of zinc into the mother's body affects the formation of the bone, cardiovascular, respiratory, and genitourinary systems. A lack of zinc increases the risk of premature birth or miscarriage.
• Zinc is essential for the normal functioning of the nervous system and brain. If zinc metabolism is impaired, the risk of developing Alzheimer's disease increases.
• Normalizes liver function.
• Supports the olfactory and taste buds and has a beneficial effect on the visual organs.
• Participates in the formation of hydrochloric acid in the gastrointestinal tract (gastrointestinal tract), maintains acid-base balance.

A serious lack of zinc is fraught with disruptions in the functioning of internal glands and metabolic processes, and the risk of neoplasms increases. Pregnant women may experience premature birth, atonic bleeding, and the uterine muscles will contract for a long time. Zinc is actively used to treat diseases of the nervous, genitourinary and circulatory systems.

Animal and plant sources of zinc

Plant sources (Table 1):

• Vegetables: broccoli, carrots, cauliflower, radishes, lettuce, spinach. As well as corn, green onions, asparagus, potatoes and tomatoes.
• Fruits and berries: citrus fruits, apples, currants, blueberries. And also raspberries, plums, cherries, pears, peach, etc.
• Nuts (walnuts, peanuts, pine, cashews, coconut).
• Dried fruits (figs, prunes, dates, dried apricots).
• Cereals: brown rice, barley, wheat bran, buckwheat, oatmeal.
• Sunflower and pumpkin seeds.
• Mushrooms.
• Green tea, cocoa.
• Legumes (peas, beans, lentils).
• Yeast.

Animal sources (Table 1):

• Chicken, rabbit, young lamb and veal.
• Fish (hake, flounder, cod, tuna, etc.). Seafood (oysters, shrimp, mussels).
• Milk, hard cheese, cottage cheese.
• Eggs.
• By-products (heart, beef tongue, liver).

Table 1. Zinc content in products

Expert advice. It is better to eat cereals unprocessed. After polishing rice, for example, its zinc content is reduced by 80%. Don’t forget to diversify your diet with animal products, they are better absorbed

• Cooking also leads to the loss of this valuable mineral. Try to eat more fresh vegetables and fruits.
• Meat products should be stewed or steamed, not fried or overcooked.
• If you don't like vegetables and fruits, drink freshly squeezed juices. They contain a higher concentration of zinc.
• Forget about porridge instant cooking, all useful ones were destroyed during processing. Daily norm Zinc intake is shown in Table 2.

Table 2. Daily value of zinc

Interaction with other elements

Organic zinc accumulates in small doses. Adsorption occurs in the gastrointestinal tract, mainly in the small intestine. An interesting fact is that zinc is absorbed faster from animal products than from fruits and vegetables. In the latter case, it is interfered with by phytic acid, which forms insoluble salt compounds with zinc.

Zinc Compatibility Features:

• Well compatible with vitamin A, it improves the absorption and bioavailability of zinc.
• Phosphorus, lithium and calcium ions (in small doses) increase the properties of zinc.
• Zinc is not compatible with copper, since they are absorbed through the same channels.
• Heavy metals (lead, cadmium) displace zinc from the body.
• Zinc cannot be taken at the same time as iron, tin and manganese, then it is absorbed worse.
• Works in tandem with vitamin E. Most often, zinc and vitamin E deficiency are diagnosed simultaneously.
• Tetracycline group drugs also displace zinc from the body.
• Additional reception folic acid slows down the absorption of microelements.
• Zinc is incompatible with Aspirin.
• Histidine and cysteine ​​are amino acids found in animal products. They improve the absorption of zinc.

Zinc deficiency

There are 3 forms of zinc deficiency: acute, subacute and chronic. The latter variant is also associated with congenital enteropathic acrodermatitis.

Zinc deficiency is manifested by the following symptoms:

• Fatigue, decreased concentration, insomnia, nervous disorders.
• Deterioration of vision, loss of taste.
• Loss of appetite, weight loss.
• Stomach upset.
• Anemia.
• Skin problems: the appearance of allergic rashes, ulcers, eczema, dermatitis. The nails are peeling and have white spots on them.
• Dull and lifeless hair, dandruff, patchy baldness.
• A decrease in insulin in the blood increases the risk of diabetes.
• In children, hypogonadism, disorders of puberty.
• Men may have problems with sexual activity, disruption of the prostate gland, and women may experience infertility.
• Decreased immunity.
• For pregnant women, zinc deficiency can lead to premature birth.

Zinc deficiency occurs if a person receives less than 7 mg from food. First of all, you need to adjust your diet by adding meat, fish and seafood to it. Don't forget about fresh vegetables and fruits. Accept mineral complexes It is necessary only as prescribed by a doctor and in the dosage prescribed by him

Excess zinc in the body

Causes of excess zinc:

• Work in hazardous industries with zinc compounds.
• Uncontrolled use of drugs containing this microelement.
• Zinc metabolism disorders.

Important! Long-term use of zinc-containing drugs (more than 100 mg per day) is fraught with the appearance of erosions, ulcers and decreased immunity. A dose of 200 mg is a strong emetic

Symptoms of excess zinc:

• Deterioration of immunity.
• Pathologies of hair, nails and skin.
• Frequent nausea, stomach pain, upset stool.
• Decreased levels of copper, cadmium and iron in the body.
• Impaired functions of the liver, prostate, pancreas.
• Sweetish taste in the mouth, frequent thirst.

If poisoning occurs due to contact with zinc fumes, this is manifested by a drop in pressure, convulsions, shortness of breath, nausea, and liver pain. If you notice characteristic symptoms, contact an endocrinologist and get tested. In case of chronic or acute excess of a trace element health care necessary. Detoxification is carried out with the drugs Acetylsalicylic acid, Unithiol, Thiosulfate.

Preparations with zinc

When choosing a drug, pay attention to what form of the substance is included in it. The most budget series use sulfates, but they are worse accepted by the body than chelate, acetate, picolinate or glycerate. The drugs are available in different forms:

• Suppositories.
• Ointments.
• Drops.
• Chewable tablets and lozenges.
• Capsules.
• Tablets, coated or uncoated.
• Effervescent tablets.

Manufacturers often produce vitamin complexes for individual groups:

• For men: ComplivitSelmevit, Duovit for men, Zinc Chelate, Zincteral, etc.
• For women: VitrumBeauty, Complivit radiance, Duovit for women, etc.
• For children: Calcium + zinc gluconate, Vitazhuyki, Vitamishki, Duovit for children, Vitrum Junior, etc.

It is advisable to take it one hour before meals or 2 hours after. It is not recommended to drink simultaneously with antibiotics, contraceptives and other drugs.

Zinc is actively used in a number of drugs:

• In rectal suppositories for hemorrhoids (Relief Ultra, Anuzol).
• In ophthalmic drops (Ophthalmol, Okumetil, Zinc sulfate).
• In single preparations (Fenuls zinc, Zincteral, Zincozac, Zinc Picolinate, etc.).
• In ointments (zinc ointment and its analogues).

Zinc is an amazing and irreplaceable element: watch the video below.

One of the metals that was discovered quite a long time ago, but to this day has not lost its relevance in use due to its remarkable properties, is zinc. Its physical and chemical properties make it possible to use the material in a wide variety of industries and everyday life. It also has a significant impact on human health.

A Brief History of the Element's Discovery

People knew what zinc was even before our era. After all, it was then that they learned to use alloys containing this metal. The Egyptians used ores containing copper and zinc, smelted them and obtained a very strong, oxidation-resistant material. Household items and dishes made from this material were found.

The name zinc appears in the writings of the physician Paracelsus in the 16th century AD. During the same period, the Chinese began to actively use the metal, casting coins from it. Gradually knowledge about this substance and its good technical properties moving to Europe. Then in Germany and England they also learned what zinc is and where it can be used.

Brass was one of the first and most famous alloys, used since ancient times in Cyprus and later in Germany and other countries.

The name comes from the Latin zincum, but the etymology is not entirely clear. There are several versions.

1. From the German zinke, which translates as "edge".
2. From the Latin zincum, meaning "white coating".
3. Persian "cheng", that is, stone.
4. Old German zinco, which translates as “plaque”, “eyesore”.

The element received its current name only at the beginning of the 20th century. The importance of zinc ions in the human body also became known only relatively recently (20th century). Before this, no ailments were associated with this element.

However, it is known that already in ancient times, many peoples used soups made from young lamb meat as a means of recovery from illness and for a speedy recovery. Today we can say that the effect was achieved due to zinc ions, which this dish contains quite a lot. It helped restore blood circulation, relieve fatigue and activated brain activity.

Element Zinc: characteristics

This element is located in periodic table in the second group, a secondary subgroup. Serial number 30, mass of Zinc - 65.37. The only and constant oxidation state is +2. Electronic configuration of the outer layer of the 4s 2 atom.

In the table, Zinc, Copper, Cadmium, Chromium, Manganese and many others are transition metals. These include all those whose electrons fill the outer and pre-external d and f energy sublevels.

Zinc salts

Almost all salts that are not double and complex, that is, do not contain foreign colored ions, are colorless. The most popular in terms of human use are the following.

1. Zinc chloride - ZnCL 2. Another name for the compound is soldering acid. Externally, it appears as white crystals that absorb air moisture well. Used to clean the surface of metals before soldering, to obtain fiber, in batteries, to impregnate wood before processing as a disinfectant.
2. Zinc sulfide. White powder, quickly turning yellow when heated. It has a high melting point, unlike pure metal. It is used in the production of luminescent compounds applied to screens, panels and other objects. Is a semiconductor.
3. - a common poison used to get rid of gnawing animals (mice, rats).
4. Smithsonite, or zinc carbonate - ZnCO 3. Colorless crystalline compound, insoluble in water. It is used in petrochemical production, as well as in silk production reactions. It is a catalyst in organic synthesis and is used as a soil fertilizer.
5. Zinc acetate - (CH 3 COO) 2 Zn. Colorless crystals, highly soluble in all solvents of any nature. Finds wide application both in the chemical, medical and food industries. Used to treat nosopharyngitis. Used as a food additive E650 - freshens breath, prevents the appearance of plaque on teeth when included in chewing gum. It is also used for pickling dyes, preserving wood, producing plastics and other organic syntheses. Almost everywhere it plays the role of an inhibitor.
6. Zinc iodide is a white crystal used in radiography, as an electrolyte in batteries, and as a dye for electron microscopy.
7. Black or dark green crystals that cannot be obtained by direct synthesis, since zinc does not react with nitrogen. Formed from metal ammonia. At high temperatures decomposes to release zinc, so it is used to obtain it.
8. Zinc nitrate. Colorless hygroscopic crystals. Zinc is used in this form in the textile and leather industries for treating fabrics.

Zinc alloys

As mentioned above, the most common zinc alloy is brass. It has been known since ancient times and is still actively used by people to this day. What is he like?

Brass is copper and zinc, which are combined harmoniously with several other metals, giving additional shine, strength and refractoriness to the alloy. Zinc is included as an alloying element, copper as the main one. The color of the material is yellow, shiny, but outdoors in a humid environment it can turn black. The melting point is about 950 o C, it can vary depending on the zinc content (the more it is, the lower the temperature).

The material is well rolled into sheets, pipes, and contact welded. Has good specifications, therefore the following elements are made from it:.

1. Machine parts and various technical devices.
2. Sleeves and stamped products.
3. Nuts, bolts, pipes.
4. Fittings, bushings, anti-corrosion parts different types transport.
5. Clock details.

Most of the metal we are considering mined in the world goes specifically to the production of this alloy.

Another type of intermetallic compound is zinc antimonide. Its formula is Zn 4 Sb 3. It is also an alloy that is used as a semiconductor in transistors, thermal imagers, and magnetoresistive devices.

It is obvious that the use of zinc and its compounds is very wide and almost everywhere. This metal is as popular as copper and aluminum, silver and gold, manganese and iron. Its importance is especially great for technical purposes as an anti-corrosion material. After all, various alloys and products are coated with zinc to protect them from this destructive natural process.

Biological role

What is zinc from a medical and biological point of view? Does it matter for the life of organisms and how great is it? It turns out that zinc ions simply must be present in living beings. Otherwise, the deficit will lead to the following consequences:

• anemia;
• decreased insulin;
• allergies;
• weight loss and memory;
• fatigue;
• depression;
• blurred vision;
• irritability and others.

The main places of concentration of zinc ions in the human body are the liver and muscles. It is also this metal that is part of most enzymes (for example, carbonic anhydrase). Therefore, most catalytic reactions occur with the participation of zinc.

What exactly do ions do?

1. Participate in the synthesis of male hormones and seminal fluid.
2. Promotes the absorption of vitamin E.
3. Participate in the breakdown of alcohol molecules in the body.
4. They are direct participants in the synthesis of many hormones (insulin, growth hormone, testosterone and others).
5. Takes part in hematopoiesis and healing of damaged tissues.
6. Regulates the secretion of the sebaceous glands, maintains normal hair and nail growth, and promotes regeneration processes in the skin.
7. It has the ability to eliminate toxins from the body and strengthen the immune system.
8. Affects the formation of taste sensations, as well as the sense of smell.
9. Takes part in transcription processes, vitamin A metabolism, nucleic synthesis and decay.
10. It is a participant in all stages of cell growth and development, and also accompanies the process of gene expression.

All this once again proves how important element is this metal. His role in biological systems was discovered only in the 20th century. Many troubles and illnesses in the past could have been avoided if people had known about treatment with zinc-based drugs.

How can you maintain the required amount of this element in the body? The answer is obvious. It is necessary to consume foods containing zinc. The list can be long, so we will indicate only those with the maximum number of the element in question:

• nuts and seeds;
• legumes;
• meat;
• seafood, especially oysters;
• cereals and bread;
• milk products;
• greens, vegetables and fruits.

Human use

We have already generally indicated in which sectors and areas of industry zinc is used. The price of this metal and its alloys is quite high. For example, a sheet of brass measuring 0.6 x 1.5 is approximately valued at 260 rubles. And this is quite justified, because the quality of the material is quite high.

So, metallic zinc, that is, as a simple substance, is used:

• for anti-corrosion coating on iron and steel products;
• in batteries;
• printing houses;
• as a reducing agent and catalyst in organic syntheses;
• in metallurgy for isolating other metals from their solutions.

It is used not only for cosmetic purposes, which we have already mentioned, but also as a filler in the production of rubber, as a white pigment in paints.

We talked about where various zinc salts are used when considering these compounds. It is obvious that, in general, zinc and its substances are important and significant components in industry, medicine and other fields, without which many processes would be impossible or very difficult.

Without “protection” they are eaten away by corrosion. It saves zinc. White-blue metal is applied to the base with a thin film.

I hear the adjective " galvanized" It is often substituted for the words: - buckets, roof coverings, wire. In the table of chemical elements, zinc is located before.

This means that it is more active, that is, it is the first to react with air.

Corrosion, as is known, is caused precisely by the contact of moisture from the atmosphere with metal.

Metal zinc the first one takes the blow, saving the metal underneath. Therefore, the buckets are galvanized, and not coated or coated.

These elements are located after iron. They will wait until this metal collapses and only then begin to disintegrate themselves.

The atomic number of zinc is 30. This is the number of the 2nd group of the 4th period of the table chemical substances. Metal designation – Zn.

He component rock ores, minerals, transported by water and even found in living tissues.

So, for example, some varieties of violets actively accumulate metal. But, highlight pure zinc succeeded only in the 18th century.

This was done by the German Andreas Sigismund Marggraff. He calcined the mixture zinc oxide With .

The experiment was a success because it was carried out without access to air, that is, oxygen. The reservoir for the reaction was a fireproof vessel made of.

The chemist placed the resulting metal vapors in the refrigerator. Under the influence of low temperatures zinc particles settled on its walls.

Zinc deposits and mining

Now, every year about 10 million tons of bluish metal in its pure form are mined in the world. Its contents in earth's crust 6-9%.

These percentages were distributed among 50 countries. The leaders are Peru, USA, Canada, Uzbekistan, but most of all zinc deposits in Australia and.

Each of these countries accounts for approximately 3 tens of millions of tons of metal with serial number 30.

However, in the future the ocean may take first place in the ranking. Basic zinc reserves concentrated in its waters, at its bottom.

However, they have not yet learned how to develop an offshore deposit. There are technologies, but they are too expensive.

Therefore, almost 3 million tons of zinc still lie at the bottom of the Red Sea, not to mention the reserves of the Caribbean and the Mid-Atlantic Ridge.

Applications of zinc

You need zinc. Metal is added to the base. Minimum doses of zinc make them malleable, easy to give in, obedient in the hands of a master.

The 30th element also brightens the product, so it is often used to create the so-called.

However, the main thing is not to overdo it with zinc. Even 3 tenths of the metal content will make it weak and brittle.

Reduces the metal and the melting point of the alloy. Compounds of copper and zinc, open, still in ancient Egypt, used in production. The alloy is cheap, easy to process, and looks attractive.

Due to its low melting point, zinc has become the “hero” of microcircuits and all kinds of devices.

It, like tin, easily and firmly connects small parts to each other. At low temperatures the metal is brittle, but already at 100-150 degrees it becomes malleable and malleable.

This physical property of zinc and is used by industrialists and artisans.

It is interesting that with even greater heat, for example, up to 500 degrees, the element again turns into brittle and unreliable.

The low melting point is financially beneficial for industrialists. You need less fuel, and there is no need to overpay for expensive equipment.

They also save on processing the resulting zinc “castings”. Their surface often does not even require additional polishing.

The metal is actively used in the automotive industry. Zinc-based alloys are used for door handles, brackets, interior decor, locks, mirror designs, and windshield wiper housings.

In the car zinc alloy high percentage. The latter makes the connection more wear-resistant and durable.

Zinc oxide is added to car tires. Without it, the rubber is of poor quality.

Cast iron and iron play a leading role in the economy of many countries. Their production is unthinkable without zinc. In brass it is from 30 to 50 percent (depending on the type of alloy).

Brass is used not only for door handles. Dishes, mixers and high-tech equipment for factories of various profiles are also made from it.

Widely used and zinc sheets. They are the basis of printing forms in printing.

The sheets are used to make power sources, pipes, roof coverings and wastewater gutters.

Zinc is an integral part of many dyes. Thus, zinc oxide is used as a white paint. By the way, this is exactly the kind of coating that is used in astronautics.

For rockets and satellites, dyes that reflect light are needed, and this is best done by zinc-based compounds.

It is also indispensable in the fight against radiation. Under its rays, metal sulfide flares up, indicating the presence of dangerous particles.

Coveted on element zinc and pharmacists. Zinc is an antiseptic. It is added to ointments for newborns and healing compositions.

Moreover, some doctors are confident that zinc, or rather its deficiency, causes schizophrenia.

Therefore, doctors adore, it is imperative to consume foods containing metal.

Seafood contains the most zinc. It’s not for nothing that metal deposits are stored in the depths of the ocean.

Zinc- a brittle transition metal of a bluish-white color (tarnishes in air, becoming covered with a thin layer of zinc oxide). Essential (irreplaceable) microelement of human tissues. In terms of quantitative ratio in the body, it ranks second, after iron, in place. It plays a key role in the regeneration of damaged tissues, since without zinc synthesis is disrupted nucleic acids and squirrel.

See also:

STRUCTURE

PROPERTIES

At room temperature fragile, when the plate is bent, a cracking sound is heard from the friction of the crystallites (usually stronger than the “cry of tin”). Has a low melting point. The volume of metal during melting increases in accordance with the decrease in density. With increasing temperature, the kinetic viscosity and electrical conductivity of zinc decrease and its specific electrical resistance. At 100-150 °C zinc is plastic. Impurities, even minor ones, dramatically increase the fragility of zinc. Is diamagnetic.

RESERVES AND PRODUCTION

The average zinc content in the earth's crust is 8.3·10 -3%; in basic igneous rocks it is slightly higher (1.3·10 -2%) than in acidic rocks (6·10 -3%). Zinc is an energetic aquatic migrant; its migration in thermal waters along with lead is especially typical. Zinc sulfides, which are of industrial importance, precipitate from these waters. Zinc also migrates vigorously to surface and groundwater, the main precipitant for it is hydrogen sulfide, sorption by clays and other processes play a lesser role.

Zinc deposits are known in Iran, Australia, Bolivia, and Kazakhstan. In Russia, the largest producer of lead-zinc concentrates is JSC MMC Dalpolimetal

Zinc is extracted from polymetallic ores containing 1-4% Zn in the form of sulfide, as well as Cu, Pb, Ag, Au, Cd, Bi. Ores are enriched by selective flotation, obtaining zinc concentrates (50-60% Zn) and at the same time lead, copper, and sometimes also pyrite concentrates.
The main method of obtaining zinc is electrolytic (hydrometallurgical). Calcined concentrates are treated with sulfuric acid; the resulting sulfate solution is cleaned of impurities (by precipitating them with zinc dust) and subjected to electrolysis in baths tightly lined inside with lead or vinyl plastic. Zinc is deposited on aluminum cathodes, from which it is removed (stripped off) daily and melted in induction furnaces.

ORIGIN

Zinc does not occur in nature as a native metal. There are 66 known zinc minerals, in particular zincite, sphalerite, willemite, calamine, smithsonite, and franklinite. The most common mineral is sphalerite, or zinc blende. The main component of the mineral is zinc sulfide ZnS, and various impurities give this substance all kinds of colors. Due to the difficulty of identifying this mineral, it is called blende (ancient Greek σφαλερός - deceptive). Zinc blende is considered the primary mineral from which other minerals of element No. 30 were formed: smithsonite ZnCO 3, zincite ZnO, calamine 2ZnO · SiO 2 · H 2 O. In Altai you can often find striped “chipmunk” ore - a mixture of zinc blende and brown spar. From a distance, a piece of such ore really looks like a hidden striped animal.

APPLICATION

Pure zinc metal is used to recover precious metals mined by underground leaching (gold, silver). In addition, zinc is used to extract silver, gold (and other metals) from crude lead in the form of zinc-silver-gold intermetallic compounds (so-called “silver foam”), which are then processed by conventional refining methods.

It is used to protect steel from corrosion (galvanization of surfaces not subject to mechanical stress, or metallization - for bridges, tanks, metal structures).

Zinc is used as a material for the negative electrode in chemical power sources, that is, in batteries and accumulators.

Zinc plates are widely used in printing, in particular, for printing illustrations in large-circulation publications. For this purpose, zincography has been used since the 19th century - making cliches on a zinc plate by etching the design in it with acid. Impurities, with the exception of a small amount of lead, impair the etching process. Before etching, the zinc plate is annealed and rolled in a heated state.

Zinc is added to many hard solders to reduce their melting point.

Zinc oxide is widely used in medicine as an antiseptic and anti-inflammatory agent. Zinc oxide is also used to produce paint - zinc white.

Zinc - important component brass Zinc alloys with aluminum and magnesium (ZAM, ZAMAK), due to their relatively high mechanical and very high casting qualities, are very widely used in mechanical engineering for precision casting. In particular, in the arms industry, pistol bolts are sometimes cast from the ZAMAK (-3, −5) alloy, especially those designed for the use of weak or traumatic cartridges. Also, all kinds of technical accessories are cast from zinc alloys, such as car handles, carburetor bodies, scale models and all kinds of miniatures, as well as any other products that require precise casting with acceptable strength.

Zinc chloride is an important flux for metal soldering and a component in fiber production.

Zinc telluride, selenide, phosphide, and sulfide are widely used semiconductors. Zinc sulfide is an integral part of many phosphors. Zinc phosphide is used as a rodent poison.

Zinc selenide is used to make optical glasses with very low absorption coefficients in the mid-infrared region, such as in carbon dioxide lasers.

Zinc - Zn

CLASSIFICATION

Zinc is a metal that is number 30 on the periodic table and has the designation Zn. It melts at a temperature of 419 °C, but if the boiling point is 913 °C, it begins to turn into steam. At normal temperatures, the condition is fragile, but at one hundred degrees it begins to bend.

The color of zinc is blue-white. When exposed to oxygen, oxidation occurs, as well as a coating of carbonate, which protects the metal from further oxidation reactions. The appearance of zinc hydroxide indicates that the water is chemical element It does not work.

Zinc is a chemical element that has its own distinctive properties, advantages and disadvantages. It is widely used in Everyday life humans, pharmaceuticals and metallurgy.

Features of zinc

Metal is necessary and widely used in almost all areas of daily human life.

Mining is mainly carried out in Iran, Kazakhstan, Australia, and Bolivia. In Russia, the manufacturer is OJSC GMK Dalpolimetal.

It is a transition metal, has an oxidation state of +2, a radioactive isotope, a half-life of 244 days.

The element is not mined in its pure form. Contained in ores and minerals: cleiophane, marmatite, wurtzite, zincite. It is necessarily present in an alloy with aluminum, copper, tin, and nickel.

Chemical, physical properties and characteristics of zinc

Zinc is a metal that has a number of properties and characteristics that distinguish it from other elements of the periodic table.

TO physical properties zinc refers to its condition. The main factor is temperature. If at room temperature it is a brittle material, the density of zinc is 7130 kg/m 3 (˃ the density of steel), which practically does not bend, then when raised it easily bends and is rolled into sheets in factories. If you take a higher temperature regime, the material acquires a liquid state, and if you raise the temperature by 400-450 °C degrees, then it will simply evaporate. This is uniqueness - changing your condition. If exposed to acids and alkalis, it can crumble, explode, or melt.

The formula of zinc is Zn – zinc. The atomic mass of zinc is 65.382 amu.

Electronic formula: the nucleus of a metal atom contains 30 protons, 35 neutrons. In atom 4 energy levels– 30 electrons. (Fig. structure of the zinc atom) 1s 2 2s 2 2p 6 3s 2 3p 6 3d 10 4s 2.

The crystal lattice of zinc is a hexagonal crystal system with tightly pressed atoms. Lattice data: A=2.66U, C=4.94.

Structure and composition of zinc

Mined and not processed material has isotopes 64, 66, 67, electrons 2-8-18-2.

In terms of application, among all the elements of the periodic table, the metal ranks 23rd. In nature, the element appears in the form of sulfide with impurities of lead Pb, cadmium Cd, iron Fe, copper Cu, silver Ag.

Depending on the amount of impurities, the metal is marked.

Zinc production

As stated above, clean look This element does not exist in nature. It is mined from other rocks, such as ore - cadmium, gallium, minerals - sphalerite.

The metal is obtained at the factory. Each plant has its own distinctive features production, so the equipment for obtaining pure material is different. It could be like this:

• The rotors, located vertically, are electrolytic.
• Special furnaces with a sufficiently high temperature for firing, as well as special electric furnaces.
• Conveyors and baths for electrolysis.

Depending on the metal mining method adopted, the appropriate equipment is used.

Obtaining pure zinc

As mentioned above, there is no pure species in nature. It is mainly extracted from ores in which it comes with various elements.

To obtain pure material, a special flotation process with selectivity is used. After the process, the ore breaks down into elements: zinc, lead, copper and so on.

The pure metal extracted by this method is fired in a special furnace. There at certain temperatures the sulfide state of the material turns into oxide. During roasting, gas containing sulfur is released, which is used to produce sulfuric acid.

There are 2 ways to obtain metal:

1. Pyrometallurgical - the burning process takes place, after which the resulting mass is restored with the help of black coal and coke. The final process is settling.
2. Electrolytic – the extracted mass is treated with sulfuric acid. The resulting solution is subjected to electrolysis, during which the metal settles and is melted in furnaces.

Smelting zinc in a furnace

The melting temperature of zinc in a furnace is 419-480 °C degrees. If the temperature is exceeded, then the material begins to evaporate. At this temperature, an admixture of iron of 0.05% is allowed.

At interest rate 0.2 iron, the sheet will be impossible to roll.

Apply various ways smelting pure metal, up to the production of zinc vapor, which is sent to special tanks and there the substance falls down.

Application of metal

The properties of zinc allow its use in many areas. As a percentage:

1. Galvanizing – up to 60%.
2. Medicine – 10%.
3. Various alloys containing this metal 10%.
4. Tire production 10%.
5. Paint production – 10%.

The use of zinc is also necessary for the restoration of metals such as gold, silver, and platinum.

Zinc in metallurgy

The metallurgical industry uses this element of the periodic table as the main one to achieve certain goals. The smelting of cast iron and steel is the main one in the entire metallurgy of the country. But these metals are susceptible negative influence environment. Without certain treatment, metals rapidly oxidize, which leads to their deterioration. The best protection galvanizing is used.

Applying a protective film to cast iron and steel is the best remedy from corrosion. About 40% of the total production of pure material is spent on galvanizing.

Galvanizing methods

Metallurgical plants are distinguished not only by their equipment, but also by the production methods used. It depends on the pricing policy, and location (natural resources used for the metallurgical industry). There are several galvanizing methods, which are discussed below.

Hot galvanizing method

This method involves dipping metal part in liquid solution. It happens like this:

1. The part or product is degreased, cleaned, washed and dried.
2. Next, the zinc is melted to a liquid state at temperatures up to 480 °C.
3. The prepared product is lowered into the liquid solution. At the same time, it is well wetted in the solution and a coating up to 450 microns thick is formed. This is 100% protection against the effects of external factors on the product (moisture, direct sunlight, water with chemical impurities).

But this method has a number of disadvantages:

• The zinc film on the product results in an uneven layer.
• This method cannot be used for parts that meet exact standards according to GOST. Where every millimeter is considered a defect.
• After hot-dip galvanizing, not every part will remain strong and wear-resistant, since brittleness appears after passing through high temperatures.

This method is also not suitable for products coated with paint and varnish materials.

Cold galvanizing

This method has 2 names: galvanic and electrolytic. The method of coating a product with corrosion protection is as follows:

1. The metal part, the product is prepared (degreased, cleaned).
2. After this, the “staining method” is carried out - a special composition is used, which has the main component - zinc.
3. The part is coated with this composition by spraying.

Thanks to this method, parts with precise tolerances and products coated with paints and varnishes are protected. Increases resistance to external factors leading to corrosion.

Flaws this method: thin protective layer – up to 35 microns. This results in less protection and shorter protection periods.

Thermal diffusion method

This method makes a coating that is an electrode with positive polarity, while the metal of the product (steel) becomes negative polarity. An electrochemical protective layer appears.

The method is applicable only if the parts are made of carbon steel, cast iron, or steel with impurities. Zinc is used in the following ways:

1. At temperatures from 290 °C to 450 °C in a powder medium, the surface of the part is saturated with Zn. Here, the marking of the steel, as well as the type of product, matter - the appropriate temperature is selected.
2. The thickness of the protective layer reaches 110 microns.
3. A product made of steel or cast iron is placed in a closed tank.
4. A special mixture is added there.
5. The last step is special processing products from the appearance of white efflorescence from salt water.

This method is mainly used when it is necessary to coat parts that have a complex shape: threads, small strokes. The formation of a uniform protective layer is important, since these parts undergo multiple exposures to external aggressive environments (constant moisture).

This method provides the highest percentage of product protection against corrosion. Galvanized coating is wear-resistant and practically indestructible, which is very important for parts that are rotated and disassembled over time.

Other uses of zinc

In addition to galvanizing, the metal is also used in other industries.

1. Zinc sheets. To produce sheets, rolling is performed, in which ductility is important. It depends on the temperature. A temperature of 25 °C gives plasticity only in one plane, which creates certain properties of the metal. The main thing here is why the sheet is made. The higher the temperature, the thinner the metal becomes. Depending on this, the product is marked Ts1, Ts2, Ts3. After this, various products for cars, profiles for construction and repair, for printing, and so on are created from the sheets.
2. Zinc alloys. For improved properties of metal products, zinc is added. These alloys are created at high temperatures in special furnaces. The most commonly produced alloys are copper and aluminum. These alloys are used for the production of bearings and various bushings, which are applicable in mechanical engineering, shipbuilding and aviation.

In household use, a galvanized bucket, trough, and sheets on the roof are the norm. Zinc is used, not chromium or nickel. And it’s not just that galvanizing is cheaper than coating with other materials. This is the most reliable and long-lasting protective material than chrome or other materials used.

As a result, zinc is the most common metal widely used in metallurgy. In mechanical engineering, construction, medicine, the material is used not only as protection against corrosion, but also to increase strength and long service life. In private houses, galvanized sheets protect the roof from precipitation; in buildings, walls and ceilings are lined with plasterboard sheets based on galvanized profiles.

Almost every housewife has a galvanized bucket or trough in her house, which she uses for a long time.