Zinc alkali. Chemical properties of zinc and its compounds

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 is spreading 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 the 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. It is widely used 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 etching 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 it decomposes with the release of zinc, therefore it is used for its production.
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 and shiny, but can turn black in the open air in a humid environment. 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. It has good technical characteristics, so 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 for various types of transport.
5. Clock details.

Most of the metal we are considering mined in the world goes into 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 this metal is. Its role in biological systems was clarified 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.

An alloy of zinc and copper - brass - was known in Ancient Greece, Ancient Egypt, India (7th century), China (11th century). For a long time it was not possible to isolate pure zinc. In 1746, A. S. Marggraf developed a method for producing pure zinc by calcining a mixture of its oxide and coal without access of air in clay refractory retorts, followed by condensation of zinc vapor in refrigerators. Zinc smelting began on an industrial scale in the 17th century.
The Latin zincum translates as “white coating.” The origin of this word is not precisely established. Presumably, it comes from the Persian "cheng", although this name does not refer to zinc, but to stones in general. The word "zinc" is found in the works of Paracelsus and other researchers of the 16th and 17th centuries. and goes back, perhaps, to the ancient German “zinc” - plaque, eyesore. The name "zinc" became commonly used only in the 1920s.

Being in nature, receiving:

The most common zinc 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. Apparently, this is why the mineral is called blende. 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.
Isolation of zinc begins with the concentration of ore using sedimentation or flotation methods, then it is roasted until oxides are formed: 2ZnS + 3O 2 = 2ZnO + 2SO 2
Zinc oxide is processed electrolytically or reduced with coke. In the first case, zinc is leached from the crude oxide with a dilute solution of sulfuric acid, the cadmium impurity is precipitated with zinc dust, and the zinc sulfate solution is subjected to electrolysis. Metal of 99.95% purity is deposited on aluminum cathodes.

Physical properties:

In its pure form it is a rather ductile silvery-white metal. At room temperature it is fragile; when the plate is bent, a cracking sound is heard from the friction of the crystallites (usually stronger than the “cry of tin”). At 100-150 °C zinc is plastic. Impurities, even minor ones, dramatically increase the fragility of zinc. Melting point - 692°C, boiling point - 1180°C

Chemical properties:

A typical amphoteric metal. The standard electrode potential is -0.76 V, in the range of standard potentials it is located up to iron. In air, zinc is coated with a thin film of ZnO oxide. It burns when heated too much. When heated, zinc reacts with halogens, with phosphorus, forming phosphides Zn 3 P 2 and ZnP 2, with sulfur and its analogs, forming various chalcogenides, ZnS, ZnSe, ZnSe 2 and ZnTe. Zinc does not react directly with hydrogen, nitrogen, carbon, silicon and boron. Zn 3 N 2 nitride is produced by the reaction of zinc with ammonia at 550-600°C.
Zinc of ordinary purity reacts actively with solutions of acids and alkalis, in the latter case forming hydroxinates: Zn + 2NaOH + 2H 2 O = Na 2 + H 2
Very pure zinc does not react with solutions of acids and alkalis.
Zinc is characterized by compounds with an oxidation state of +2.

The most important connections:

Zinc oxide- ZnO, white, amphoteric, reacts with both acid solutions and alkalis:
ZnO + 2NaOH = Na 2 ZnO 2 + H 2 O (fusion).
Zinc hydroxide- forms as a gelatinous white precipitate when alkali is added to aqueous solutions of zinc salts. Amphoteric hydroxide
Zinc salts. Colorless crystalline substances. In aqueous solutions, zinc ions Zn 2+ form aqua complexes 2+ and 2+ and undergo severe hydrolysis.
Zincates are formed by the interaction of zinc oxide or hydroxide with alkalis. When fused, metazincates are formed (for example, Na 2 ZnO 2), which, dissolving in water, turn into tetrahydroxo zincates: Na 2 ZnO 2 + 2H 2 O = Na 2. When solutions are acidified, zinc hydroxide precipitates.

Application:

Production of anti-corrosion coatings.
- Metallic zinc in the form of bars is used to protect against corrosion of steel products in contact with sea water. Approximately half of all zinc produced is used in the production of galvanized steel, one third in hot-dip galvanizing of finished products, and the rest for strip and wire.
- Another area of ​​application is the production of dry cell batteries, although this has decreased significantly in recent years.
- Zinc telluride ZnTe is used as a material for photoresistors, infrared radiation receivers, dosimeters and radiation counters. - Zinc acetate Zn(CH 3 COO) 2 is used as a fixative for dyeing fabrics, a wood preservative, an antifungal agent in medicine, and a catalyst in organic synthesis. Zinc acetate is a component of dental cements and is used in the production of glazes and porcelain.

Zinc is one of the most important biologically active elements and is essential for all forms of life. Its role is due mainly to the fact that it is part of more than 40 important enzymes. The function of zinc in proteins responsible for recognizing the sequence of bases in DNA and, therefore, regulating the transfer of genetic information during DNA replication has been established. Zinc is involved in carbohydrate metabolism with the help of the zinc-containing hormone insulin. Vitamin A is effective only in the presence of zinc. Zinc is also necessary for bone formation.
At the same time, zinc ions are toxic.

Bespotestnykh S., Shtanova I.
HF Tyumen State University, 571 group.

Sources: Wikipedia:

Chemical properties

The external electronic configuration of the Zn atom is 3d 10 4s 2. The oxidation state in compounds is +2. The normal redox potential of 0.76 V characterizes Zinc as an active metal and an energetic reducing agent. In air at temperatures up to 100 °C, zinc quickly tarnishes, becoming covered with a surface film of basic carbonates. In air, zinc is coated with a thin film of ZnO oxide. When heated strongly, it burns to form amphoteric white oxide ZnO.

2Zn + O 2 = 2ZnO

Dry fluorine, chlorine and bromine do not react with Zinc in the cold, but in the presence of water vapor the metal can ignite, forming, for example, ZnCl 2. A heated mixture of zinc powder and sulfur gives zinc sulfide ZnS. Zinc sulfide precipitates when hydrogen sulfide acts on weakly acidic or ammonia aqueous solutions of Zn salts. ZnH 2 hydride is obtained by reacting LiAlH 4 with Zn(CH 3) 2 and other zinc compounds; a metal-like substance that decomposes into elements when heated.

Nitride Zn 3 N 2 - black powder, is formed when heated to 600 ° C in a stream of ammonia; stable in air up to 750 °C, water decomposes it. Zinc carbide ZnC 2 was obtained by heating zinc in a stream of acetylene. Strong mineral acids vigorously dissolve zinc, especially when heated, to form the corresponding salts. When interacting with dilute HCl and H 2 SO 4, H 2 is released, and with HNO 3, in addition, NO, NO 2, NH 3. Zinc reacts with concentrated HCl, H 2 SO 4 and HNO 3, releasing H 2, SO 2, NO and NO 2, respectively. Solutions and melts of alkalis oxidize zinc, releasing H2 and forming water-soluble zincites. The intensity of the action of acids and alkalis on zinc depends on the presence of impurities in it. Pure zinc is less reactive towards these reagents due to its high hydrogen overvoltage. In water, Zinc salts hydrolyze when heated, releasing a white precipitate of Zn(OH) 2 hydroxide. Complex compounds containing Zinc are known, for example SO 4 and others.

Zinc oxide reacts both with acid solutions:

ZnO + 2HNO 3 = Zn(NO 3) 2 + H 2 O

and with alkalis:

ZnO + 2NaOH (fusion) = Na 2 ZnO 2 + H 2 O

Zinc of ordinary purity reacts actively with acid solutions:

Zn + 2HCl = ZnCl 2 + H2

Zn + H 2 SO 4 = ZnSO 4 + H 2

and alkali solutions:

Zn + 2NaOH + 2H 2 O = Na 2 + H 2

forming hydroxinates. Very pure zinc does not react with solutions of acids and alkalis. The interaction begins when a few drops of copper sulfate solution CuSO 4 are added.

When heated, zinc reacts with non-metals (except hydrogen, carbon and nitrogen). Reacts actively with acids:

Zn + H 2 SO 4 (diluted) = ZnSO 4 + H 2

Zinc is the only element of the group that dissolves in aqueous solutions of alkalis to form 2– ions (hydroxycinates):

Zn + 2OH – + 2H 2 O = 2– + H 2

When metallic zinc is dissolved in an ammonia solution, an ammonia complex is formed:

Zn + 4NH 3 H 2 O = (OH) 2 + 2H 2 O + H 2

Introduction

The element zinc (Zn) in the periodic table has serial number 30. It is in the fourth period of the second group. Atomic weight - 65.37. Distribution of electrons over layers 2-8-18-2

The origin of the element's name is unclear, but it seems plausible that it is derived from Zinke (German for "point" or "tooth"), due to the appearance of the metal.

Zinc is a bluish-white metal that melts at 419 C and turns into steam at 913 C; its density is 7.14 g/cm3. At ordinary temperatures, zinc is quite brittle, but at 100-110 C it bends well and is rolled into sheets. In air, zinc is coated with a thin layer of oxide or basic carbonate, protecting it from further oxidation.

Water has almost no effect on zinc, although it is located in the voltage series significantly to the left of hydrogen. This is explained by the fact that the hydroxide formed on the surface of zinc when it interacts with water is practically insoluble and prevents the further course of the reaction. In dilute acids, zinc easily dissolves to form the corresponding salts.

In addition, zinc, like beryllium and other metals that form amphoteric hydroxides, dissolves in alkalis. If zinc is heated in air to its boiling point, its vapor ignites and burns with a greenish-white flame, forming zinc oxide

When heated, zinc reacts with non-metals (except hydrogen, carbon and nitrogen). Reacts actively with acids:

Zn + H2SO4 (diluted) = ZnSO4 + H2

Zinc is the only element of the group that dissolves in aqueous solutions of alkalis to form ions (hydroxycinates):

Zn + 2OH + 2H2O = + H2

1. Raw materials for zinc production

Research Institute "Uralmekhanobr" (owned by UMMC) has developed a technology for extracting metallized pellets and zinc concentrate from electric steelmaking waste. The new method will allow metallurgists to obtain inexpensive raw materials and solve environmental problems.

The source of zinc is ore, which is usually in the sulfide state, and zinc is represented mainly by sphalerite (ZnS). Ores are always complex, containing, in addition to zinc, lead, copper, iron, silver, etc. Recently, secondary raw materials have been used in countries with high consumption.

The raw material is zinc concentrate. As a source material, not only mineral and secondary materials are used, but also zinc-containing products from other industries: slag and dust from metallurgical production of lead, copper, tin, cast iron. These products are much poorer in zinc than zinc concentrates and are still included in zinc raw materials. Until recently, zinc slags were considered waste products, although they contain significant amounts of zinc, especially in lead slags (10-17% zinc).

Distribution of zinc in nature and its industrial extraction. The zinc content in the earth's crust is 7.6 10–3%, it is approximately the same as rubidium (7.8 10–3%) and slightly more abundant than copper (6.8 10–3%) .

The main zinc minerals are zinc sulfide ZnS (known as zincblende or sphalerite) and zinc carbonate ZnCO3

Canada ranks first in the world in terms of production (16.5% of world production, 1113 thousand tons, 1995) and reserves of zinc. In addition, rich zinc deposits are concentrated in China (13.5%), Australia (13%), Peru (10%), USA (10%), Ireland (about 3%).

Zinc mining is carried out in 50 countries. In Russia, zinc is extracted from copper pyrite deposits in the Urals, as well as from polymetallic deposits in the mountains of Southern Siberia and Primorye. Large zinc reserves are concentrated in Rudny Altai (Eastern Kazakhstan), which accounts for more than 50% of zinc production in the CIS countries. Zinc is also mined in Azerbaijan, Uzbekistan (Almalyk deposit) and Tajikistan.

The innovation of the technology is that it allows you to simultaneously obtain zinc and metallic iron from waste. This has not been possible before. The essence of the process was explained by the head of the department of agglomeration of ores and concentrates at Uralmekhanobra, Samuil Melamud: “Dust along with blast furnace slag and other iron-containing waste are pelletized and loaded into a specially created rotary kiln. It creates a special atmosphere and firing regime (this is where the know-how lies), which makes it possible to extract zinc and metallize the iron present in oxide form. Zinc is captured in fabric bag filters, and the pellets are cooled, processed and transferred for metallurgical processing.”

According to scientists, on average, from one ton of dust it is possible to obtain 300 - 350 kg of metallic iron and 50 - 70 kg of zinc. A new method of recycling waste will allow you to use cheap recyclable materials, reduce the cost of storing hazardous waste and reduce environmental charges. As a result, the cost of the resulting zinc will be 15 - 20% lower than its current world prices (1.9 thousand tons on the London Metal Exchange). The payback period for new installations with a volume of 20 - 30 thousand tons of processing per year is no more than four years.

Currently, an economic feasibility study is being prepared for the feasibility of introducing the technology at UMMC enterprises: Metallurgical Plant named after. A.K. Serov, Vtortsvetmet (Sukhoi Log), Mednogorsk copper and sulfur plant. In the future, it is planned to sell licenses for the right to use know-how to other metal companies.

Scientists from OJSC Uralmekhanobr (an enterprise of the UMMC scientific complex), together with UMMC specialists, have developed a new technology for domestic and foreign ferrous metallurgy enterprises for the extraction of zinc and iron from dust from electric furnace production. The innovation of the technology lies in the fact that it makes it possible to simultaneously obtain zinc and metallic iron from raw materials, which was not previously possible.

According to one of the authors of the development, the head of the department of agglomeration of ores and concentrates at Uralmekhanobr OJSC, Samuil Melamud, the technology ensures the extraction of metallized pellets and zinc concentrate through the reduction roasting of zinc-containing dust. Preliminary results showed that from a ton of dust from the Metallurgical Plant. A.K. Serov, you can get 300–350 kg of metallic iron and 50–70 kg of zinc.

“Increasing costs for the extraction of ore raw materials and scrap, limited natural resources and the expected increase in penalties for environmental pollution naturally lead to the fact that industrialists are beginning to take the issues of recycling man-made waste more and more seriously,” says Samuel Melamud. “Moreover, modern technologies can already be economically profitable.”

In April of this year, pilot tests of the new technology were successfully completed at the Mednogorsk copper and sulfur plant (Orenburg region, an enterprise of the UMMC metallurgical complex). Currently, an economic feasibility study is being prepared for introducing the technology at one of the UMMC enterprises

2. Methods for obtaining zinc

With sudden cooling, zinc vapor immediately, bypassing the liquid state, turns into solid dust. It is often necessary to preserve zinc in the form of dust, rather than melt it into ingots.

Zinc does not appear in nature as a native metal. Zinc is mined in two ways:

1) pyrometallurgical method

2) hydrometallurgical method 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. Zinc concentrates are fired in fluidized bed furnaces, converting zinc sulfide into ZnO oxide; The resulting sulfur dioxide SO2 is used to produce sulfuric acid. There are two routes from ZnO to Zn.

1) According to the pyrometallurgical (distillation) method, which has existed for a long time, the calcined concentrate is subjected to sintering to impart granularity and gas permeability, and then reduced with coal or coke at 1200 - 1300 ° C:

ZnO + C = Zn + CO.

The resulting metal vapors are condensed and poured into molds. At first, reduction was carried out only in retorts made of baked clay, operated manually, later they began to use vertical mechanized retorts made of carborundum, then - shaft and arc electric furnaces; Zinc is obtained from lead-zinc concentrates in blast furnaces. Productivity gradually increased, but zinc contained up to 3% impurities, including valuable cadmium. Distillation zinc is purified by segregation (that is, by settling the liquid metal from iron and part of the lead at 500 °C), achieving a purity of 98.7%. The sometimes more complex and expensive purification by rectification produces metal with a purity of 99.995% and allows the recovery of cadmium.

The main method of obtaining zinc is electrolytic (hydrometallurgical). The roasted 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. Typically, the purity of electrolytic zinc is 99.95%, the completeness of its extraction from the concentrate (taking into account waste processing) is 93-94%. Zinc sulfate, Pb, Cu, Cd, Au, Ag are obtained from production waste; sometimes also In, Ga, Ge, Tl.

2) The hydrometallurgical method for processing roasted zinc concentrates consists of dissolving zinc oxide with an aqueous solution of sulfuric acid and subsequent precipitation of zinc by electrolysis. Therefore, the hydrometallurgical method is sometimes called electrolytic. When producing zinc by electrolysis, the zinc concentrate is first subjected to oxidative roasting.

ZnSO4→ Zn 2+ + SO4 2-

2+ (–) cathode Zn, Н2О (+) anode: SO42–, Н2О

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 of chemical substances. Metal designation – Zn.

It is a component of rock ores, minerals, is transported by water and is 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 content in the earth's crust is 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, discovered in ancient Egypt, are 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 isn't just 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.