What mineral is iron obtained from? Iron minerals in the ancient history of mankind. What is geochemistry

Iron is found in red blood cells, muscle tissue, spleen, liver and bone marrow.

Functions of iron in the body:

• plays important role in the functioning of the immune system.
• necessary for transporting oxygen to the cells of the whole body.
• participates in the creation of red blood cells and enzymes.
• participates in the synthesis of thyroid hormones.
• affects the condition of the skin, hair and nails.
• takes part in regeneration processes.

For iron absorption, normal gastric juice secretion is necessary. Lack of iron in the body, in turn, leads to a deterioration in gastric secretion.

The absorption of iron in the body is hindered by some components of tea and coffee, as well as phytin, bran fiber, soy protein and calcium. Iron is not absorbed from milk and dairy products.

Vitamin C, organic acids, some simple carbohydrates (lactose, fructose, sorbitol) and amino acids (histidine and lysine) improve the absorption of iron in the body.

Symptoms of iron deficiency:

• weakness,
• pallor,
• headache,
• fast fatiguability,
• increased excitability and depression,
• cardiopalmus,
• pain in the heart area,
• dry mouth,
• infectious diseases caused by decreased immunity,
• anemia and anemia.

Excess iron

Iron poisoning is a serious and common problem:

• Iron poisoning often occurs where iron is found in drinking water.
• During oxygen starvation, the body compensates for the lack of oxygen by increasing the concentration of hemoglobin.
• Approximately 15% of people carry a gene (the “Celtic genome”) that causes the body to accumulate iron.

Some symptoms of iron poisoning (excess iron) are similar to those of iron deficiency:

• pallor,
• thinness,
• weakness,
• heart rhythm disturbances.

A characteristic sign of excess iron is pigmentation in places where it should not be: on the palms, armpits.

Excess iron is very dangerous. Iron accumulation occurs mainly in the liver, pancreas and heart muscle, which has a detrimental effect on the poisoned organs. If iron poisoning continues, diseases such as:

• hepatitis, liver cirrhosis,
• diabetes,
• joint diseases, arthritis,
• diseases of the nervous system,
• serious diseases of the cardiovascular system,
• cancer of poisoned organs.

With an excess of iron, complex measures should be taken:

• Follow proper nutrition to normalize metabolism.
• To walk outside.
• Start playing sports.
• In extreme cases, bloodletting (blood donation) will help.

Daily dose of iron

Recommended daily norm iron intake is very approximate. It is impossible to calculate the exact dose, since the absorption of iron in the body depends on the state of the body itself and on related factors. A blood test should be done if iron deficiency or excess is suspected.

That's why, The daily allowance is given for reference only:

• Boys from 14 to 18 – 11 mg.
• Girls from 14 to 18 15 mg.
• Men from 19 to 70 – 8 mg.
• Women from 19 to 50 – 18 mg.
• Women 50 and older - 8 mg.

Iron in foods

Often, iron deficiency occurs with a sharp change in the type of diet, tk. any drastic change in lifestyle is a severe stress for the body. In addition, in assimilation it takes Active participation intestinal microflora, which must also change.

• More than 1 mg of iron per 100 g contain: watermelon, artichoke, swede, melon, Brussels sprouts, sweet peppers, radishes, radishes, beets, tomatoes, Jerusalem artichoke, spinach (up to 3 mg) and sorrel (up to 2 mg). Other vegetables contain 0.4 to 0.9 mg of iron per 100 g.
• Rich in iron: plum and apple juice, dried apricots, raisins, nuts, pumpkin and sunflower seeds.
• Wholemeal bread, black bread, bran (wheat and rye), cereals, herbs, salad vegetables, cabbage also contain a lot of iron.

6. In terms of the total (as of 01.01.2003 - 100 billion tons - 16.1% of the world) and explored (56.1 billion tons - 18.6% of the world) iron ore reserves, Russia steadily ranks first in the world , fully satisfies its needs for iron ore raw materials and exports significant volumes of commercial iron ores, concentrates, pellets, and hot briquetted iron annually.

7. Iron ore deposits of industrial importance are very diverse. They are known in endogenous, exogenous and metamorphogenic rock complexes. Taking into account the genesis, it is customary to distinguish the following main industrial types.

8. Igneous deposits:

a) titanomagnetite and ilmenite-titanomagnetite, which are zones of concentrated dissemination (with schlieren and vein-lens-like segregations) of vanadium- and titanium-containing magnetites in intrusions of gabbro-pyroxenite-dunite, gabbro, gabbro-diabase and gabbro-anorthosite formations (Kachkanarskoye, Kopanskoye, Pervouralskoye in the Urals, Pudozhgorskoye in Karelia, Chineyskoye in the Chita region, deposits of the Bushveld complex in South Africa, Rowtivara, Taberg in Sweden, Allard Lake (Lac-Tio) in Canada, etc.);

b) baddeleyite-apatite-magnetite, forming a series of lens- and vein-shaped bodies in ultrabasic alkaline intrusions with carbonatites (Kovdorskoe on the Kola Peninsula, Palabora in South Africa).

Titanium magnetite and baddeleyite-apatite-magnetite ores account for 6.6% of the world's proven reserves and 5.6% of commercial ore production. In Russia they account for 12.9% of reserves and 18.2% of commercial ore production.

9. Metasomatic deposits (deposits of skarn-magnetite ores) are represented to varying degrees by mineralized skarns and skarnoids, forming complex sheet- and lens-shaped deposits of magnetite ores in sedimentary, volcanic-sedimentary and metamorphic rocks (Sokolovskoye, Sarbaiskoye, Kacharskoye in Kazakhstan; Vysokogorskoye, Goroblagodatskoye and others in the Urals; Abakanskoye, Teyskoye in the Krasnoyarsk Territory; Sheregeshevskoye, Tashtagolskoye and others in Mountain Shoria; Taezhnoe, Desovskoye in Yakutia; Marcona in Peru, deposits of the Chilean iron ore belt; Chogart, Chador-Malu in Iran; Maanshan in China). Skarn-magnetite ores account for 9.5% of the world's proven reserves and 8.3% of commercial ore production. Ores of this type in Russia account for 12.2 and 12.9%, respectively.

10. Hydrothermal deposits:

a) genetically associated with traps and represented by vein-columnar deposits of various complex shapes of magnetite ores in sedimentary, pyroclastic rocks and traps (Korshunovskoe, Rudnogorskoe, Neryundinskoe, Kapaevskoe, Tagarskoe in Eastern Siberia);

b) hydrothermal-sedimentary siderite, hematite-siderite, represented by sheet-, vein- and lens-shaped consonant and cutting deposits of siderite, hematite-siderite (in the upper horizons of oxidized) ores in sedimentary rocks (Bakalskoye ore field in the Urals, Berezovskoye in the Chita region, Huenza, Bou Kadra, Zakkar Beni Saf in Algeria, Bilbao in Spain).

The share of ores of this type in explored reserves and production of commercial ores in the world is insignificant and does not exceed 1%; in Russia it is 5.4% in reserves, and 2.9% in production of commercial ores.

11. Volcanogenic-sedimentary deposits - conformable layers and lenses of hematite, magnetite-hematite and hematite-magnetite ores in volcanogenic-sedimentary rocks (West Karazhalskoye in Kazakhstan, Kholzunskoye in Altai). The share of ores of this type in the explored reserves and production of commercial ores in the world is insignificant. Such deposits have not yet been developed in Russia.

12. Sedimentary offshore deposits formed in marine basins and represented by weakly dislocated reservoir deposits of leptochlorite and hydrogoethite oolitic ores in marine terrigenous-carbonate Meso-Cenozoic deposits (Kerch iron ore basin in Ukraine, Ayatskoye in Kazakhstan, brown iron ore deposits of the Lorraine iron ore basin (in France, Belgium, Luxembourg), Great Britain, Germany, the province of Newfoundland in Canada and the Birmingham region in the USA). Ore share of this type in proven reserves in the world is 10.6%, in the production of commercial ores - 8.9%. In Russia, such deposits have not been explored or developed.

13. Sedimentary continental deposits formed in river or lake basins and represented by bedded and lenticular deposits of leptochlorite and hydrogoethite oolitic ores in fossil river sediments (Lisakovskoye in Kazakhstan). The share of ores of this type in the explored reserves and production of marketable ores in the world is insignificant. In Russia, such deposits have not been explored or developed.

14. Metamorphosed ferruginous quartzites are widespread on ancient shields, platforms, and on some median massifs of the Phanerozoic folded regions. Most of them are of Early Proterozoic and Archean age; Late Proterozoic and Early Paleozoic deposits are much less common. Ferrous quartzites form huge iron ore basins. Ore deposits of quartzites within deposits usually have large dimensions: kilometers along strike, a few hundreds or tens of meters in thickness. The stratified form of ore bodies, thin-striped textures and a similar mineral composition of ores at various deposits are characteristic (the Krivoy Rog basin in Ukraine, in Russia - deposits of the Kursk magnetic anomaly, Olenegorskoe on the Kola Peninsula, Kostomuksha in Karelia, Tarynnakhskoe and Gorkitskoe in Yakutia, in Australia - the Hamersley basin , in Brazil - the region of Carajas and the "Iron Quadrangle", in the USA - the region of Lake Superior, in Canada - the Labrador Trough, in China - the Anshan-Benxi basin, etc.). Large and unique deposits in terms of reserves, easy dressing of ores, the possibility of open-pit mining in large quarries using powerful mining and transport equipment make it possible to consider them favorable objects for the extraction of iron ore in all basins of the world. The share of ores of this type in the explored reserves and production of marketable ores in the world exceeds 60%, in Russia in reserves it is 55.9%, in the production of marketable ores - 64.5%.

15. Deposits of weathering crusts, represented by rich hydrohematite- and siderite-magnetite, martite-magnetite ores, are formed during the transformation of ferruginous quartzites as a result of supergene processes. In accordance with this, in their distribution they are associated with regions and areas of development of ferruginous quartzites, confined to the areal and linear weathering crusts developing along them (Mikhailovskoe, Yakovlevskoe, Gostishchevskoe, Vislovskoe, Razumenskoe in Russia, rich ore deposits of Krivoy Rog in Ukraine, iron ore areas Australia, Brazil, India, USA). Deposits of this type account for 12.5% ​​of Russia's proven reserves and 1.3% of commercial ore production. In total, the share of deposits of the last two types - ferruginous quartzites and polygenic rich iron ores developing on them - amounts to 70.9% of explored reserves and 74.4% of the production of marketable ores in the world, i.e. these are the most important industrial types of deposits. The share of ores of the last two types of deposits in Russia is 68.4% in reserves, and 65.8% in the production of commercial ores.

16. Other supergene iron ores:

a) brown iron ores associated with weathering crusts of siderites (Bakalskaya and Zigazino-Komarovskaya groups of deposits in the Urals, Berezovskoye in the Chita region);

b) intermittent cloak-like deposits of chromium-nickel goethite-hydrogoethite ores, common in the weathering crust of ultrabasic rocks (laterite ores of Cuba, the Philippines, Indonesia, Guinea, Mali, in the Urals - Serovskoye and deposits of the Orsk-Khalilovsky region). Such ores are usually alloyed with nickel and cobalt.

The share of other supergene iron ores in proven reserves in the world is 2.4%, in the production of commercial ores - 2.0%, in Russia 1.1 and 0.2%, respectively.

17. Depending on the conditions of formation, the mineral composition of iron ores is extremely diverse, which largely determines their industrial value. Iron ores are divided into 11 main industrial types (Table 2).

Goals. Introduce the position of iron in periodic table chemical elements of D.I. Mendeleev, atomic structure, natural deposits, compounds, modern methods of production, properties and uses of iron. To promote the development in schoolchildren of skills of collective work and comradely mutual assistance.
Equipment and reagents. Test tubes, tables on blast furnace production; solutions of HCl and H 2 SO 4, powders of Fe(OH) 2 and Fe(OH) 3, iron filings, solutions of yellow blood salt K 4 and red blood salt K 3.
Lesson type. Elements of lecture, story, conversation.

DURING THE CLASSES

Teacher. Today we will continue our talk about metals, you will learn about the position of iron in the periodic table of chemical elements, the structure of its atom, the chemical properties of the metal iron, its compounds, production and use, the role of iron in the development of human society. What is the role of iron in human society?
Student. Iron played a big role in the development of human society and has not lost its importance today. Of all the metals, it is the most widely used in modern industry.
Primitive man began to use iron tools several millennia BC. In those years, the only source of this metal was meteorites that fell to the ground, which contain fairly pure iron. In the middle of the 2nd millennium BC
n. e. In Egypt, iron metallurgy was mastered - extracting it from iron ores. This event marked the beginning of the Iron Age in human history, which replaced the Stone and Bronze Ages. On the territory of Russia, the beginning of the Iron Age dates back to the turn of the 2nd–1st millennia BC. e.
Teacher. What is the distribution of iron in nature?
Student. Iron is one of the most common elements in nature. In the earth's crust, its mass fraction is 5.1%, according to this indicator it is second only to oxygen, silicon and aluminum. A lot of iron is also found in celestial bodies, as determined by spectral analysis. In samples of lunar soil delivered by the Soviet automatic station "Luna", iron was found in an unoxidized state..
Teacher. In what form does iron occur in nature?
Student. Iron is a component of most rocks. To obtain iron, iron ores with an iron content of 30–70% or more are used.(Using physical card Russia, the student shows and names deposits of iron compounds.)
The main iron ores are:

– hematite Fe 2 O 3 – contains up to 65% iron, such iron deposits are found in the Krivoy Rog region;
– limonite Fe2O3 n H2O – contains up to 60% iron, limonite deposits are found in the Crimea, for example the Kerch deposit;
– pyrite FeS 2 – contains approximately 47% iron, pyrite deposits are found in the Urals.
Teacher. How is iron obtained in industry?
Student. Currently, the main industrial method of processing iron ores is the production of cast iron by the blast furnace process. Cast iron is an iron alloy containing
2.2–4% carbon, as well as silicon, manganese, phosphorus, sulfur. Subsequently, most of the cast iron is converted into steel. Steel differs from cast iron mainly in its lower carbon content (up to 2%), phosphorus and sulfur.
Teacher. Much attention is paid to the development of methods for the direct production of iron from ores without the blast furnace process. What is the advantage of getting iron directly? The main thing is that the reduction of iron oxides can be carried out without the participation of metallurgical coke. It is being replaced by cheaper and more common fuel - brown coal, natural gas. In the direct production of iron, low-grade iron ores and slags from other industries containing iron can also be used.
Direct reduction of iron is carried out in slightly inclined rotary kilns, similar to the kilns used to make cement. Ore and coal are continuously loaded into the furnace, which gradually move to the outlet, heated air flows in countercurrent, creating a temperature below the melting point of iron.
To obtain technically pure iron by direct reduction, the ore is subjected to beneficiation. At the same time, it is possible to increase the mass fraction of iron, separate waste rock (pieces of iron are easily separated from the slag) and reduce the content of harmful impurities (sulfur and phosphorus). During the beneficiation process, ore is crushed in crushing plants and fed into a magnetic separator. The latter is a drum with electromagnets into which crushed ore is fed using a conveyor. The waste rock passes freely through the magnetic field and falls. The ore grains containing magnetic iron minerals are magnetized and separated from the drum later than the gangue. So magnetic separation can be done several times.
The ore is then enriched using the method flotation. To do this, the ore is placed in a container of water, where flotation surfactants are dissolved, which are selectively absorbed on the surface of the useful mineral. As a result of the absorption of the flotation reagent, the mineral particles are not wetted by water and do not sink in it. Air is passed through the solution, the bubbles of which attach to the pieces of mineral and lift them to the surface. Particles of waste rock are well wetted by water and settle at the bottom of the container. The enriched ore is collected from the surface of the solution along with the foam. As a result, the iron content in the ore can be increased to 70–72%.
Let's consider a diagram of one of the methods for directly obtaining iron. The process is carried out in a vertical furnace, into which enriched ore is fed from above, and gas, which serves as a reducing agent, from below. This gas is produced by burning natural gas in the absence of oxygen. Reducing gas contains 30% CO , 55% H 2 , 13% H 2 O and 2% CO 2 . Therefore, the reducing agents are carbon(II) monoxide CO and hydrogen:

Fe 2 O 3 + 3CO = 2Fe + 3CO 2,

Fe 2 O 3 + 3H 2 = 2Fe + 3H 2 O.

Reduction is carried out at a temperature of 850–900 °C, which is lower than the melting point of iron (1539 °C).
Many modern branches of technology require very much iron high degree cleanliness. Then the technical iron is cleaned carbonyl method. Carbonyls are compounds of metals with carbon monoxide (II) CO. Iron interacts with CO when high blood pressure and temperature 100–200 °C, forming iron pentacarbonyl:

Iron pentacarbonyl is a liquid that can easily be separated from impurities by distillation. At a temperature of about 250 °C, carbonyl easily decomposes, forming iron powder:

Fe(CO) 5 = Fe + 5CO.

If the resulting powder is sintered in a vacuum, the result is a metal containing 99.98–99.999% iron. Why do you need to obtain metal of such purity?
Student. Iron of a high degree of purity is needed primarily to study its properties, i.e. for scientific purposes. If it had not been possible to obtain pure iron, they would not have known that it is a soft, easily processed metal. Chemically pure iron is much more inert than industrial iron. An important industry in the use of pure iron is the production of special ferroalloys, the properties of which deteriorate from the presence of impurities..
Teacher. What are the chemical properties of iron?
Student. Chemical properties iron are determined by the structure of the electronic shells of its atoms. Iron is an element of the secondary subgroup of group VIII of the 4th major period. Iron belongs to the d-elements, the electronic formula of the atom has the ending …3d 6 4s 2 . Iron in compounds exhibits oxidation states +2 and +3. The maximum oxidation state of iron is +6. It manifests itself in ferrates - salts of non-existent ferric acid. For example, Na 2 FeO 4 – sodium ferrate.
Teacher. How does iron react with oxygen?
Student. In the electrochemical series of voltages, iron is to the left of hydrogen, i.e., it has a more negative standard electrode potential. Therefore, iron easily dissolves in hydrochloric and dilute sulfuric acids with the release of hydrogen:

Fe + 2HCl = FeCl 2 + H 2,

Fe + H 2 SO 4 (diluted) = FeSO 4 + H 2.

Iron reduces more concentrated sulfuric acid (40–60%) to
sulfur(IV) oxide:

Fe + 2H 2 SO 4 = FeSO 4 + SO 2 + 2H 2 O.

In sulfuric acid of even higher concentration (from 80 to 100%) iron passivated- covered with a thin and durable oxide film, which protects the metal from dissolution. The same passivation phenomenon is observed in highly concentrated nitric acid, so concentrated sulfuric and nitric acids can be transported in iron containers.
With dilute nitric acid, iron can react to form an iron(II) salt, and with a more concentrated acid solution, iron(III) salts and various acid reduction products, for example:

4Fe + 10HNO 3 = 4Fe(NO 3) 2 + NH 4 NO 3 + 3H 2 O,

3Fe + 8HNO 3 = 3Fe(NO 3) 2 + 2NO + 4H 2 O,

Fe + 6HNO 3 = Fe(NO 3) 3 + 3NO 2 + 3H 2 O.

Teacher. Remember what is called corrosion. What are its consequences?
Student. Corrosion is the destruction of metal under the influence of the environment. Rust formation can be represented as follows:

4Fe + 3O 2 + 6H 2 O = 4Fe(OH) 3,

Rust exfoliates from the surface of the metal, has many pores, and therefore does not protect the metal from further corrosion. Due to corrosion, a huge amount of iron and its alloys perish. In the 19th century, when there were no reliable methods to combat corrosion, half of the smelted metal perished from it. IN modern conditions 1/6 of the iron being smelted perishes from corrosion. Therefore, the fight against corrosion is one of the most important tasks of mankind..
Teacher. Are iron compounds amphoteric?
(The question posed can be answered by the teacher himself or by a pre-prepared student interested in chemistry.)
Iron(III) hydroxide is amphoteric, i.e. it exhibits the properties of a base in reaction with acids:

Fe(OH) 3 + 3HCl = FeCl 3 + 3H 2 O,

And acid properties in reactions with concentrated alkali solutions:

Iron(III) oxide also has an amphoteric character, which reacts with both acids and basic oxides:

Fe 2 O 3 + 6HCl = 2FeCl 3 + 3H 2 O,

The teacher draws students' attention to the fact that there are characteristic reactions to compounds of divalent and trivalent iron, accompanying his story with experiments.
Teacher. To detect iron(III) ions, it is convenient to use an iron complex compound called yellow blood salt or potassium hexacyanoferrate(II). K4. When ions interact(Fe(CN) 6) 4– with ions Fe 3+ a dark blue precipitate is formed - Prussian blue:

Another iron compound is red blood salt or potassium hexacyanoferrate(III) K 3 is a reagent for ions Fe2+.
When ions interact(Fe(CN) 6) 3– with ions Fe 2+ a dark blue precipitate is also formed - Turnboole blue:

List the main uses of iron. Which natural value has iron?
(Students answer the questions posed, the teacher explains their answers.)
First student. Ferrates of various metals are used in modern industries of radio electronics and automation..
Second student. Iron forms unusual compounds with hydrogen, nitrogen and carbon. The atoms of these nonmetals are smaller in size than iron atoms and are easily embedded between nodes crystal lattice metal, forming interstitial solid solutions.

Interstitial solid solutions are similar in appearance to metal, but their properties are very different from those of iron. For the most part these are very hard and brittle substances. Iron forms hydrides with hydrogen FeH And FeH2, with nitrogen - nitrides Fe4N And Fe2N , with carbon – carbide Fe 3 C – cementite contained in cast iron and steel.
Third student. Iron is a metal whose use in industry and everyday life has no limits. Steel is widely used in modern technology. Iron oxides and salts are used in the production of paints, magnetic materials, catalysts, medicines, and fertilizers.
Fourth student. Without iron, the human body cannot function; it contains about 3–4 g of iron, of which 2 g is in the blood. Iron is part of hemoglobin. Insufficient iron content in the human body leads to headaches, fatigue and other diseases. Iron is also necessary for plant growth. In general, iron is currently the main metal in importance.

To consolidate the material studied, students are offered the following: questions.

1. What is the position of iron in the periodic table of chemical elements?
2. What oxidation states does iron exhibit in compounds?
3. Which iron compounds have amphoteric properties?
4. How does iron react with nitric and sulfuric acids of various concentrations?
5. How to distinguish between divalent and trivalent iron compounds?
6. What is the use and significance of iron compounds at the present stage of human development?

If time permits, you can consolidate the considered material for the production of iron using the following questions.

1. What is the advantage of the direct method of obtaining iron?
2. What is ore beneficiation used for?
3. How is ore enriched by flotation?
4. What is the main purpose of purifying industrial iron using the carbonyl method?

LITERATURE

Book to read inorganic chemistry. Comp. V.A.Kritsman, M.: Education, 1984;
Feldman F.G., Rudzitis G.E. Chemistry. Textbook for 9th grade of general education institutions. M.: Education, 1999;
Khomchenko G.P. Chemistry for those entering universities. M.: graduate School, 1993.

Iron belongs to the group of native elements. Native iron is a mineral of terrestrial and cosmogenic origin. The nickel content is 3 percent higher in terrestrial iron compared to cosmogenic iron. It also contains impurities of magnesium, cobalt and other trace elements. Native iron has a light gray color with a metallic luster; inclusions of crystals are rare. This is a fairly rare mineral with a hardness of 4-5 units. and a density of 7000-7800 kg per cubic meter. Archaeologists have proven that native iron was used by ancient people long before they developed the skills to smelt iron metal from ore.

This metal in its original form has a silvery-white tint; the surface quickly becomes covered with rust in high humidity or in oxygen-rich water. This breed It has good ductility, melts at a temperature of 1530 degrees Celsius, and can be easily forged into products and rolled. The metal has good electrical and thermal conductivity; it is additionally distinguished from other rocks by its magnetic properties.

When interacting with oxygen, the surface of the metal is covered with the resulting film, which protects it from corrosive effects. And when there is moisture in the air, iron oxidizes and rust forms on its surface. In some acids, iron dissolves and hydrogen is released.

The history of iron

Iron had a huge impact on the development of human society and continues to be valued today. It is used in many industries. Iron helped primitive man to master new methods of hunting and led to the development Agriculture thanks to new tools. Pure iron in those days was part of fallen meteorites. To this day, there are legends about the unearthly origin of this material. Metallurgy dates back to the middle of the second millennium BC. At that time, Egypt mastered the production of metal from iron ore.

Where is iron mined?

In its pure form, iron is found in celestial bodies. The metal was discovered in lunar soil. Now iron is mined from rock ore, and Russia occupies a leading position in the extraction of this metal. Rich deposits of iron ore are located in the European part, in Western Siberia and in the Urals.

Areas of use

Iron is essential in the production of steel, which has a wide range of applications. This material is used in almost every production. Iron is widely used in everyday life; it can be found in the form of forged products and cast iron. Iron allows you to give the product different shape, therefore it is used in forging and creating gazebos, fences and other products.

All housewives use iron in the kitchen, because products made of cast iron are nothing more than an alloy of iron and carbon. Cast iron cookware heats up evenly, maintains temperature for a long time and lasts for decades. Almost all cutlery includes iron, and stainless steel is used to make dishes and various kitchen utensils and such necessary items as shovels, forks, axes and other useful utensils. This metal is also widely used in jewelry.

Chemical composition

Telluric iron contains impurities of nickel (Ni) 0.6-2%, cobalt (Co) up to 0.3%, copper (Cu) up to 0.4%, platinum (Pt) up to 0.1%, carbon; in meteorite iron, nickel ranges from 2 to 12%, cobalt is about 0.5%, and there are also impurities of phosphorus, sulfur, and carbon.

Behavior in acids: dissolves in HNO3.
In nature, there are several modifications of iron - the low-temperature one has a bcc cell (Im3m), the high-temperature (at temperatures > 1179K) the fcc cell (Fm(-3)m). Found in large quantities in meteorites. Widmanstätten figures appear in iron meteorites when etched or heated.
Origin: telluric (terrestrial) iron is rarely found in basaltic lavas (Uifak, Disko Island, off the western coast of Greenland, near Kassel, Germany). At both points, pyrrhotite (Fe1-xS) and cohenite (Fe3C) are associated with it, which is explained by both reduction by carbon (including from the host rocks) and the decomposition of carbonyl complexes such as Fe(CO)n. In microscopic grains, it has more than once been established in altered (serpentinized) ultrabasic rocks, also in paragenesis with pyrrhotite, sometimes with magnetite, due to which it arises during reduction reactions. Very rarely found in the oxidation zone of ore deposits, during the formation of swamp ores. Findings have been recorded in sedimentary rocks associated with the reduction of iron compounds with hydrogen and hydrocarbons.
Almost pure iron was found in lunar soil, which is associated with both meteorite falls and magmatic processes. Finally, two classes of meteorites - stony-iron and iron - contain natural iron alloys as a rock-forming component.

Native iron family (according to Godovikov)
Native iron group
< 2,9, редко до 6,4 ат. % Ni - феррит
< ~ 6,4 ат. % Ni - камасит

Native Nickel Group
> 24 at. % Ni - taenite
62.5 - 92 at. % Ni - awaruite Ni3Fe
(Ni, Fe) - Native nickel

Iron (English Iron, French Fer, German Eisen) is one of the seven metals of antiquity. It is very likely that man became acquainted with iron of meteorite origin earlier than with other metals. Meteoric iron is usually easy to distinguish from terrestrial iron, since it almost always contains from 5 to 30% nickel, most often 7-8%. Since ancient times, iron has been obtained from ores that occur almost everywhere. The most common ores are hematite (Fe 2 O 3,), brown iron ore (2Fe 2 O 3, ZN 2 O) and its varieties (swamp ore, siderite, or spar iron FeCO3,), magnetite (Fe 3 0 4) and some others . All these ores, when heated with coal, are easily reduced at a relatively low temperature, starting from 500 o C. The resulting metal had the appearance of a viscous spongy mass, which was then processed at 700-800 o With repeated forging.

In ancient times and the Middle Ages, the seven then known metals were compared with the seven planets, which symbolized the connection between metals and celestial bodies and the celestial origin of metals. This comparison became common more than 2000 years ago and is constantly found in literature until the 19th century. In the II century. n. e. iron was compared with Mercury and was called mercury, but later it began to be compared with Mars and called Mars, which, in particular, emphasized the external similarity of the reddish color of Mars with red iron ores.

Properties of the mineral

• Origin of name: Designation chemical element- from the Latin ferrum, Iron - from the Old English word meaning this metal
• Opening location: Qeqertarsuaq Island (Disko Island), Qaasuitsup, Greenland
• Opening year: known since ancient times
• Thermal properties: P. tr. Melting point (pure iron) 1528°C
• IMA status: valid, first described before 1959 (before IMA)
• Typical impurities: Ni,C,Co,P,Cu,S
• Strunz (8th edition): 1/A.07-10
• Hey's CIM Ref.: 1.57
• Dana (7th edition): 1.1.17.1
• Molecular Weight: 55.85
• Cell parameters: a = 2.8664Å
• Number of formula units (Z): 2
• Unit cell volume: V 23.55 ų
• Twinning: by (111)
• Point group: m3m (4/m 3 2/m) - Hexoctahedral
• Space group: Im3m (I4/m 3 2/m)
• Separateness: by (112)
• Density (calculated): 7.874
• Density (measured): 7.3 - 7.87
• Type: isotropic
• Reflected color: white
• Selection form: Form of crystalline deposits: dense grains with irregular sinuous outlines, films, dendrites, and occasionally nuggets.
• USSR taxonomy classes: Metals
• IMA classes: Native elements
• Chemical formula: Fe
• Syngony: cubic
• Color: Steel grey, grey-black, white on polished surface
• Trait color: Gray-black
• Shine: metal
• Transparency: opaque
• Cleavage: imperfect by (001)
• Kink: hooked splintered
• Hardness: 4 5
• Microhardness: VHN100=160
• Ductility: Yes
• Magnetity: Yes
• Literature: Zaritsky P.V., Dovgopolov S.D., Samoilovich L.G. Composition and genesis of the native iron ore occurrence in the town of Ozyornaya in the river basin. Chickens. - Bulletin of Kharkov University, 1986, No. 283 (Central Siberia) Meltser M.A. and others. Native iron in the gold-bearing veins of the Allah-Yun region and some questions of their genesis. - New data on the geology of Yakutia. Ya., 1975, p. 74-78

Photo of the mineral

Articles on the topic

• Iron is one of the seven metals of antiquity.
  It is very likely that man became acquainted with iron of meteorite origin earlier than with other metals

Deposits of the mineral Iron

• Krasnoyarsk region
• Russia
• Kugda, Khatanga, Taimyr.

Lesson objectives:

Educational:

• Based on students’ knowledge of the structure of metal atoms, the features chemical bond, properties of metals - simple substances and their compounds, study the structural features of the iron atom and trace the relationship between the structure of the iron atom, its properties and the properties of its compounds; get acquainted with the most important connections gland.
• To develop cognitive interest in the subject, to realize interdisciplinary connections between courses in chemistry, biology, history, geography and literature.

Developmental:

• To develop students’ ability to analyze, compare, generalize and draw conclusions based on existing and newly acquired knowledge, both in chemistry and in other disciplines.
• Instill search and independent work skills.
• Continue to work on developing skills in applying knowledge when solving theoretical and practical problems(formation of subject competence).

Educational: During the lesson, promote the formation of a scientific worldview, communicative and information competence.

Lesson type: A lesson in learning new knowledge. Primary consolidation of new knowledge.

Form of organization of educational activities of students: group work, predominant work - independent. Lesson with elements technologies of critical thinking.

Equipment: PSCE, metal crystal lattices, videos confirming the chemical properties of iron and its compounds, reagents (iron powder, sulfur, solutions of hydrochloric and sulfuric acids, copper sulfate, sodium hydroxide, red and yellow blood salts, iron (II) sulfate, ferric chloride (III), potassium thiocyanate), multimedia equipment, a disk with a recording of the presentation, an electronic manual on the topic "Metals".

DURING THE CLASSES

I. Organizing time(1-2 min)

Stage 1“Challenge”. At this phase, the knowledge available to students is updated, and interest in the issue under discussion arises.

Brief introduction teachers (3 min.).

Today we will continue our journey into the world of metals: we will not only explore the present, but also look into the distant past. The attention of visitors to the World Industrial Exhibition in 1958 in Brussels was attracted by the Atomium building. Nine huge metal balls, 18 meters in diameter, seemed to float in the air: eight at the tops of the cube, the ninth in the center. This was a model of the unit cell of crystalline alpha iron, magnified 165 billion times (slide 2)

The teacher announces the topic of the lesson: “Iron and its compounds” (slide 3)

Reception "Let's dig into memory"

Stage 2- Understanding new information. The teacher offers students new information that they must learn. At this stage, you may be asked to work with the text, fill out a matrix table, read the text with notes, or extract from the text.

Finding iron in nature.

Pupils are given printed material (The most important natural compounds of iron) and minerals containing iron are demonstrated.

Working with a table.

Answer the questions: a) What classes of inorganic compounds are included in the composition of iron minerals? b) Which mineral has the highest mass fraction of iron? c) In which regions of Russia is iron mined?

The most important natural iron compounds(slide 4)

2. Physical properties gland. Iron crystal lattices (slide 5,6,7)

Reception "Cluster"

1. Write the key expression in the middle of the sheet: “Physical properties of iron”

2. Start writing down words or sentences that come to mind in connection with this task.

H. As you come up with ideas and write them down, begin to make connections between the ideas that feel right to you.

4. Write down as many ideas as come to your mind until all your ideas are exhausted.

At this stage of the lesson, it is possible to use the “Marking table” technique (working with the text, students fill out the table), for example:

3. Position of the iron atom in the periodic table and structure of the atom(slide 8)

26 Fe)))) d - element VIII-B group, Ar = 56 1s 2 2s 2 2p 6 3s 2 3p 6 3d 6 4s 2

4. Chemical properties of iron(Slide 9,10)

At this stage of the lesson, it is possible to use the “Self-Analysis” technique based on knowledge of the general properties of metals.

A) When heated, it interacts with many non-metals:

* with oxygen 3Fe + 2O 2 = Fe 3 O 4

* with chlorine 2Fe + 3Cl 2 = 2FeCl 3

* sulfur Fe + S = FeS

* with nitrogen 2Fe + N 2 = 2FeN

B) Water vapor is decomposed by hot iron: 3Fe + 4H 2 O = Fe 3 O 4 + 4H 2

C) Dilute HCL and H 2 SO 4 dissolve iron.

Fe + H 2 SO 4 = FeSO 4 + H 2 Fe + 2HCl = FeCl 2 + H 2

D) With concentrated nitric and sulfuric acids at normal conditions does not react (acids passivate the metal)

E) When heated, the reaction with concentrated sulfuric acid proceeds according to the equation 2Fe + 6H 2 SO 4 = Fe 2 (SO 4) 3 + 3SO 2 + 6H 2 O

E) Interacts with salts: Fe + CuCl 2 = FeCl 2 + Cu

5. Properties of Fe +2 and Fe +3 compounds(slide 11, 12)

6. Laboratory experiments. Qualitative reactions to Fe +2, Fe +3 ions.

1. To a solution of iron (II) sulfate - (FeSO 4) add a few drops of a solution of potassium hexacyanoferrate (III) - red blood salt K 3. We observe the precipitation of Turnboule's blue. What colour?

Write the reaction equation: FeSO 4 + K 3 ->

2. To a solution of iron (III) chloride - (FeCl 3) add a few drops of a solution of potassium hexacyanoferrate (II) K 4 - yellow blood salt. Note the color of the Prussian blue precipitate. Write down the reaction equation:

FeCl 3 + K 4 ->

3. Add a few drops of potassium thiocyanate (KCNS) solution to the iron (III) chloride solution. Observe the color of the solution. Write down the reaction equation:

FeCl 3 + KCNS ->

7. Practical significance of iron salts(slide 13)

1. FeSO 4 * 7H 2 O - iron sulfate; used in textile industry when dyeing fabrics, in agriculture for seed treatment and pest control, obtaining ink.
2. FeCl 2 - iron (II) chloride; used to obtain pure iron, a component of antianemic drugs, a catalyst in organic synthesis.
3. FeCl 3 - iron (III) chloride; It is used in technology as an oxidizing agent in the production of organic dyes, in the textile industry - for etching fabrics when preparing them for dyeing, in medicine as a hemostatic agent, a component of tinting solutions in photography, a coagulant in water purification, for the determination of phenols.
4. Fe 2 (SO 4) 3 - iron (III) sulfate; applied as chemical reagent during hydrometallurgical processing copper ores, as a coagulant in wastewater treatment, for the production of alum, Fe 2 O 3 pigment.

Stage 3- Reflection, Contemplation. All information received at stage 2 is comprehended. Reflection and generalization of “what the child learned” in the lesson on this issue. At this stage, a supporting outline can be compiled in the student's notebook. In addition, the following can be done:

a) return to the call stage;

b) return to keywords;

c) return to inverted logical chains;

d) return to clusters.

It is possible to use the following techniques: "Confused logical chains"

or "Sinquain":

• on the first line the topic is called in one word (noun)
• the second line is a description of the topic in two words (adjectives).
• the third line is a description of the action within the topic using three verbs.
• the fourth is a four-word phrase showing the attitude towards the topic.
• the fifth is a one-word synonym that will repeat the essence of the topic.

or "Constructing text" (slide 14)

Task: From the proposed formulas of compounds, compose the genetic series Fe +2 (for the first option) and the genetic series Fe +2 (for the second option).

Fe(OH) 2, Fe, Fe(OH) 2, FeCl 3, Fe 2 O 3, FeCl 2, FeO

8. Homework (slide 14)

1. Write equations of chemical reactions that can be used to carry out the following transformations:

Fe -> FeCl 3 -> Fe(OH) 3 -> Fe 2 O 3 -> Fe -> FeSO 4 -> Fe(OH) 2 -> FeOa Fe -> Fe 3 O 4

2. Write the reaction equations for the stepwise hydrolysis of a Fe 2 (SO 4) 3 solution.

3. In Eq. chemical reaction arrange coefficients using method electronic balance: Fe 2 O 3 + KOH + KNO 3 -> K 2 FeO 4 + KNO 2 + H 2 O