All the known chemical element iron treats averages on chemical activity to metals kindly. In the nature it does not meet in pure form, and is a part of minerals. Iron takes on the prevalence on Earth the fourth place among chemical elements. Without it it is just impossible to present mankind today.
It is necessary to distinguish the following from all variety of the minerals containing in the chemical composition ferrum especially:
- the magnetite containing 72% of iron (Fe3O4) which is called still magnetic iron ore; possesses in flowers from light gray to black, the main fields in the territory of the CIS are in the Urals;
- hematite or red iron ore consists for 70% of a ferrum (Fe2O3); coloring from red-gray to red-brown shades, the biggest field is in Kryvyi Rih;
- limonite or hematite for 60% consists of this element, the crystal lattice contains molecules of water (Fe2O3*H2O); color scale from yellowy-brown to brown flowers, the most large-scale deposits are found in the Crimea and in the Urals;
- siderite or shpatovy iron ore consists of iron for 48% (FeCO3), the non-uniform structure of substance contains crystals of various flowers: light green, gray, yellowy-brown, gray-yellow and others;
- pyrite for 46% from the lump contains ferrum (FeS2), possesses golden-yellow coloring.
It is difficult to overestimate value of iron, it is an important microcell for living cells, is a part of hemoglobin which influences a condition of human blood. Many minerals which part iron is are applied to receiving pure chemical element. And hematite and pyrite, for example, use also for production of a jewelry.
Iron has physical and chemical properties. And treat physical properties, density, appearance, melting temperature, etc., and to chemical – ability to react with other elements and connections.
Physical properties of iron
Under normal conditions and in pure form iron represents the solid substance possessing in silver-gray color with characteristic metal gloss. This element has the fourth (average) level of hardness on Moos's scale. Good heat conductivity and conductivity is characteristic of it. It is easy to check the first property on own feelings, having touched an iron subject on cold when metal very quickly cools the surface of skin. Having compared these feelings to the similar experiment made with a wooden subject, for example, it is possible to establish this property in its accurate regularity.
Melting temperature (1539 degrees Celsius) and boilings (2860 degrees Celsius) belongs to important physical properties of iron. It follows from this that ferrum differs in easily fusibility. Besides, the great plasticity and a ferromagnitnost is peculiar to iron. The last property of a ferrum favourably distinguishes it from other metals. This element is capable to be magnetized. The created properties of metal under the influence of magnetic field are capable to remain quite long time that eloquently demonstrates that at structure of iron there is a large number of free electrons.
Chemical properties of iron
Ferrum treats metals with average chemical activity. Together with group of the metals which are in an electrochemical row is more right than hydrogen, iron shows typical properties, reacting with many classes of chemicals. For example, nitrogen, oxygen, halogens (bromine, iodine, fluorine, chlorine), carbon fabrics, phosphorus.
Oxides of iron turn out at combustion of iron at high temperatures. Chemical reactions depend on skilled conditions and proportions of substances. The equations can look as follows: 2Fe+O2=2FeO; 3Fe+2O2=Fe3O4; 4Fe+3O2=2Fe2O3.
Interaction of iron with nitrogen is also possible only at high temperature of reaction. Reaction formula: 6Fe+N2=2Fe3N.
Rub asking a ferrum and one mol of phosphorus are capable to form iron phosphide: 3Fe+P=Fe3P.
Besides, by the above-stated principle there is an education and sulfides (interaction of a ferrum to sulfur). For acceleration of chemical reactions the special conditions of their carrying out except high temperatures mean also use of catalysts.
Reactions of iron with halogens became widespread in chemical industry. Iodination, bromination, chlorination and fluoration concern them. At high temperatures ferrum it is capable to connect to silicon also.
Except simple chemical reactions of iron with substances which molecular structure includes only one element it is necessary to mention and more difficult. In such chemical reactions ferrum connects to the substances consisting of two and more elements. First of all compound of iron with water belongs to such reactions: Fe+H2O=FeO+H2. However depending on proportions of the substances participating in reaction it is possible to receive not only oxide of iron, but also hydroxide, either di - or iron trioxide. All these substances found broad application, both in chemical industry, and in many other industries.
The ability of this chemical element to force out hydrogen from connections creates an opportunity at addition of iron to acid (for example to sulfuric acid of average concentration) in the corresponding equal proportions to receive sulfate and hydrogen: Fe+H2SO4=FeSO4+H2.
Recovery properties of a ferrum are observed in interaction with salts. For example, by means of iron it is possible to emit less active metal from salt. So, one mol of a ferrum and one mol of sulfate of copper will create pure copper and sulfate of iron in identical proportions.
Value of iron for a human body
Iron is one of the most widespread chemical elements which are in earth crust. For a human body at the cellular level this metal plays very important role. It is a part of protein - hemoglobin. And it, in turn, carries out transportation of oxygen in blood to all fabrics and bodies. Ferrum is very important for formation of blood and enzymes, work of a thyroid gland, a metabolism at the cellular level, stability of immunity, neutralization of hazardous substances in a liver. The daily dose of this microcell in a human body makes from 10 mg to 20 mg.
The use in a food allowance of the products of animal and plant origin rich with iron, will allow to give to an organism support, sufficient for normal functioning. First of all the liver and meat belong to such foodstuff. But also, cereals, grain (especially buckwheat) and bean, apples, dried fruits and mushrooms (especially white), pears, peaches and dogrose, almonds, avocado and pumpkin, broccoli, tomatoes and dates, bilberry, cabbage, celery, blackberry and others.
Symptoms of low contents in an organism of a ferrum are the increased fatigue, the depressions cold to an extremity, fragility of nails and hair, low intellectual activity and operability, digestive disorders and violations of normal functioning of a thyroid gland.
Industrial use of iron
The most expressed physical and chemical properties of iron defined also the sphere of its use. So, its ferromagnitnost was the reason of production of magnets. And the high durability of metal defined its use in production of weapon, military and household tools.
The greatest application was found by iron at production of steel and cast iron which, in turn, became important initial materials for the huge list of finished products practically in all spheres of activity of the person. Compound of iron with carbon in different proportions also is way of production of steel (carbon less than 1.7%) or cast iron (carbon from 1.7% to 4.5%). And for production of steel of various brands also rather wide list of other chemical elements is used. Manganese, silicon, phosphorus, nickel, molybdenum, chrome, tungsten and other substances concerns them.