Iron is a well-known chemical element. It refers to metals with average chemical activity. The properties and application of iron we will consider in this article.
Prevalence in nature
There are a fairly large number of minerals, which include ferrum. First of all, it is magnetite. It is seventy-two percent iron. Its chemical formula is Fe 3 O 4 . This mineral is also called magnetic iron ore. It has a light gray color, sometimes with a dark gray, up to black, with a metallic sheen. Its largest field among the CIS countries is in the Urals.
The next high iron mineral, hematite, is seventy percent composed of this element. Its chemical formula is Fe 2 O 3 . It is also called red iron ore. It has a color from red-brown to red-gray. The largest field in the CIS countries is located in Krivoy Rog.
The third ferrum mineral is limonite. Here, iron is sixty percent of the total mass. This is a crystalline hydrate, that is, water molecules are woven into its crystal lattice, its chemical formula is Fe 2 O 3 • H 2 O. As the name implies, this mineral has a yellowish-brownish color, sometimes brown. It is one of the main components of natural ocher and is used as a pigment. It is also called brown iron ore. The largest occurrence sites are Crimea and the Urals.
In siderite, the so-called spar iron ore, forty-eight percent of the ferrum. Its chemical formula is FeCO 3 . Its structure is heterogeneous and consists of crystals of different colors connected together: gray, pale green, gray-yellow, brown-yellow, etc.
The last naturally occurring mineral with a high ferrum content is pyrite. He has the chemical formula FeS 2 . Iron contains forty-six percent of the total mass. Thanks to sulfur atoms, this mineral has a golden yellow color.
Many of the minerals examined are used to produce pure iron. In addition, hematite is used in the manufacture of jewelry made from natural stones. Pyrite inclusions can be found in lapis lazuli jewelry. In addition, iron is found in nature as part of living organisms - it is one of the most important components of the cell. This trace element must necessarily enter the human body in sufficient quantities. The healing properties of iron are largely due to the fact that this chemical element is the basis of hemoglobin. Therefore, the use of ferrum has a good effect on the state of the blood, and therefore, the whole organism as a whole.
Iron: physical and chemical properties
Let us consider in order these two large sections. The physical properties of iron are its appearance, density, melting point, etc. That is, all the distinguishing features of matter that are associated with physics. The chemical properties of iron are its ability to react with other compounds. Let's start with the first.
Physical properties of iron
In its pure form, under normal conditions, it is a solid. It has a silver-gray color and a pronounced metallic sheen. The mechanical properties of iron include a Mohs hardness level . It is equal to four (average). Iron has good electrical and thermal conductivity. The last feature can be felt by touching an iron object in a cold room. Since this material quickly conducts heat, it takes a large part of it from your skin in a short period of time, and therefore you feel cold.
Touching, for example, a tree, it can be noted that its thermal conductivity is much lower. The physical properties of iron are its melting and boiling points. The first is 1539 degrees Celsius, the second is 2860 degrees Celsius. It can be concluded that the characteristic properties of iron are good ductility and fusibility. But this is far from all.
Also in the physical properties of iron is its ferromagnetism. What it is? Iron, the magnetic properties of which we can observe on practical examples every day, is the only metal with such a unique distinguishing feature. This is because this material is able to magnetize under the influence of a magnetic field. And upon the termination of the latter, the iron, whose magnetic properties have just been formed, remains a magnet for a long time. This phenomenon can be explained by the fact that in the structure of this metal there are many free electrons that are able to move.
In terms of chemistry
This element refers to metals of medium activity. But the chemical properties of iron are typical for all other metals (except those that are to the right of hydrogen in the electrochemical series). It is able to react with many classes of substances.
Let's start with simple
Ferrum interacts with carbon, nitrogen, halogens (iodine, bromine, chlorine, fluorine), phosphorus, carbon. The first thing to consider is the reaction with oxygen. When ferrum is burned, its oxides are formed. Depending on the reaction conditions and the proportions between the two participants, they can be diverse. As an example of such interactions, the following reaction equations can be given: 2Fe + O 2 = 2FeO; 4Fe + 3O 2 = 2Fe 2 O 3 ; 3Fe + 2O 2 = Fe 3 O 4 . And the properties of iron oxide (both physical and chemical) can be varied, depending on its variety. This kind of reaction occurs at high temperatures.
The following is interaction with nitrogen. It can also occur only when heated. If we take six moles of iron and one mole of nitrogen, we get two moles of iron nitride. The reaction equation will look as follows: 6Fe + N 2 = 2Fe 3 N.
When interacting with phosphorus, phosphide is formed. The following components are necessary for carrying out the reaction: for three moles of ferrum, one mole of phosphorus, as a result one mole of phosphide is formed. The equation can be written as follows: 3Fe + P = Fe 3 P.
In addition, among reactions with simple substances, interaction with sulfur can also be distinguished. In this case, sulfide can be obtained. The principle by which the process of formation of this substance occurs is similar to that described above. Namely, the addition reaction occurs. For all chemical interactions of this kind, special conditions are needed, mainly high temperatures, less often catalysts.
Reactions between iron and halogens are also common in the chemical industry. These are chlorination, bromination, iodination, fluorination. As is clear from the names of the reactions themselves, this is the process of attachment of chlorine / bromine / iodine / fluorine atoms to ferrum atoms with the formation of chloride / bromide / iodide / fluoride, respectively. These substances are widely used in various industries. In addition, ferrum is able to combine with silicon at high temperatures. Due to the fact that the chemical properties of iron are diverse, it is often used in the chemical industry.
Ferrum and complex substances
We will pass from simple substances to those whose molecules consist of two or more different chemical elements. The first thing to mention is the reaction of ferrum with water. Here the basic properties of iron are manifested. When water is heated, the basic oxide is formed together with iron (it is called so because it reacts with the same water to form hydroxide, in other words, the base). So, if you take one mole of both components, substances are formed such as ferrum dioxide and hydrogen in the form of a gas with a pungent odor - also in one to one molar proportions. An equation of this kind of reaction can be written as follows: Fe + H 2 O = FeO + H 2 . Depending on the proportions in which to mix these two components, it is possible to obtain iron or trioxide. Both of these substances are very common in the chemical industry, and are also used in many other industries.
With acids and salts
Since ferrum is located to the left of hydrogen in the electrochemical series of metal activity, it is capable of displacing this element from compounds. An example of this is the substitution reaction, which can be observed when iron is added to the acid. For example, if you mix iron and sulfate acid (it is sulfuric) of medium concentration in the same molar proportions, as a result we get iron sulfate (II) and hydrogen in the same molar proportions. The equation of such a reaction will look like this: Fe + H 2 SO 4 = FeSO 4 + H 2 .
When interacting with salts, the reducing properties of iron are manifested. That is, with it you can select a less active metal from salt. For example, if you take one mole of copper sulfate and the same amount of ferrum, you can get iron sulfate (II) and pure copper in the same molar proportions.
Value for the body
One of the most common chemical elements in the earth's crust is iron. We have already considered the properties of a substance ; now we will approach it from a biological point of view. Ferrum performs very important functions both at the cellular level and at the level of the whole organism. First of all, iron is the basis of such a protein as hemoglobin. It is necessary for the transport of oxygen through the blood from the lungs to all tissues, organs, to each cell of the body, primarily to the neurons of the brain. Therefore, the beneficial properties of iron cannot be overestimated.
Besides the fact that it affects blood formation, ferrum is also important for the full functioning of the thyroid gland (this requires not only iodine, as some people think). Also, iron takes part in intracellular metabolism, regulates immunity. Even ferrum is found in especially large quantities in the liver cells, as it helps to neutralize harmful substances. It is also one of the main components of many types of enzymes in our body. In the daily diet of a person should contain from ten to twenty milligrams of this microelement.
Iron rich foods
There are many of them. They are of both plant and animal origin. The first are cereals, legumes, cereals (especially buckwheat), apples, mushrooms (white), dried fruits, rose hips, pears, peaches, avocados, pumpkin, almonds, dates, tomatoes, broccoli, cabbage, blueberries, blackberries, celery, etc. The second is the liver, meat. The use of foods high in iron is especially important during pregnancy, since the body of the forming fetus requires a large amount of this microelement for full growth and development.
Signs of a lack of iron in the body
Symptoms of too little ferrum entering the body include fatigue, constant freezing of hands and feet, depression, brittle hair and nails, decreased intellectual activity, digestive upsets, poor performance, and thyroid problems. If you notice several of these symptoms, you should increase the number of foods with iron in your diet or buy vitamins or nutritional supplements containing ferrum. You should also consult a doctor if you feel any of these symptoms too acutely.
The use of ferrum in industry
The use and properties of iron are closely related. Due to its ferromagnetism, it is used for the manufacture of magnets - both weaker for household purposes (souvenir fridge magnets, etc.) and stronger ones for industrial purposes. Due to the fact that the metal in question has high strength and hardness, it has been used since ancient times for the manufacture of weapons, armor and other military and household tools. By the way, even in Ancient Egypt, meteorite iron was known, whose properties are superior to those of ordinary metal. Also, such special iron was used in ancient Rome. Elite weapons were made from it. A shield or sword made of meteorite metal could only be had by a very rich and noble man.
In general, the metal that we consider in this article is the most versatile used among all substances in this group. First of all, steel and cast iron are made from it, which are used for the production of all kinds of products necessary both in industry and in everyday life.
Cast iron is an alloy of iron and carbon, in which the second is present from 1.7 to 4.5 percent. If the second is less than 1.7 percent, then this kind of alloy is called steel. If there is about 0.02 percent carbon in the composition, then this is an ordinary technical iron. The presence of carbon in the alloy is necessary to give it greater strength, heat resistance, and resistance to rust.
In addition, steel may contain many other chemical elements as impurities. This is manganese, and phosphorus, and silicon. Also, chromium, nickel, molybdenum, tungsten and many other chemical elements can be added to this kind of alloy to give it certain qualities. Types of steel in which a large amount of silicon is present (about four percent) are used as transformer. Those, which contain a lot of manganese (up to twelve to fourteen percent), find their application in the manufacture of parts of railways, mills, crushers and other tools, parts of which are subject to rapid abrasion.
Molybdenum is introduced into the alloy to make it more heat-resistant - such steels are used as tool steels. In addition, to obtain stainless steel known and often used in everyday life in the form of knives and other household tools, it is necessary to add chromium, nickel and titanium to the alloy. And in order to get impact-resistant, high-strength, ductile steel, just add vanadium to it. When niobium is introduced into the composition, high resistance to corrosion and chemically aggressive substances can be achieved.
The mineral magnetite, which was mentioned at the beginning of the article, is needed for the manufacture of hard drives, memory cards and other devices of this type. Due to its magnetic properties, iron can be found in transformers, motors, electronic products, etc. In addition, ferrum can be added to alloys of other metals to give them greater strength and mechanical stability. Sulfate of this element is used in gardening to control pests (along with copper sulfate).
Iron chlorides are indispensable in water treatment. In addition, magnetite powder is used in black and white printers. The main method of using pyrite is to obtain sulfuric acid from it. This process takes place under laboratory conditions in three stages. In the first stage, pyrite of the ferrum is burned, thereby obtaining iron oxide and sulfur dioxide. At the second stage, the conversion of sulfur dioxide to its trioxide occurs with the participation of oxygen. And at the final stage, the resulting substance is passed through
steam in the presence of catalysts, thereby obtaining sulfuric acid.
Iron production
This metal is mainly mined from its two main minerals: magnetite and hematite. They do this by reducing iron from its compounds with carbon in the form of coke. This is done in blast furnaces, the temperature of which reaches two thousand degrees Celsius. In addition, there is a way to restore ferrum with hydrogen. For this, a blast furnace is not necessary. To implement this method, they take special clay, mix it with crushed ore and process it with hydrogen in a shaft furnace.
Conclusion
The properties and uses of iron are diverse. This is perhaps the most important metal in our lives. Having become known to mankind, he took the place of bronze, which at that time was the main material for the manufacture of all tools, as well as weapons. Steel and cast iron are in many ways superior to the alloy of copper with tin in terms of their physical properties and resistance to mechanical stress.
In addition, iron on our planet is more common than many other metals. Its mass fraction in the earth's crust is almost five percent. This is the fourth most abundant chemical element in nature. Also, this chemical element is very important for the normal functioning of the organism of animals and plants, primarily because hemoglobin is built on its basis. Iron is an essential trace element, the use of which is important for maintaining the health and normal functioning of organs. In addition to the above, this is the only metal that has unique magnetic properties. Without ferrum, it is impossible to imagine our life.