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Rud where. Iron ore. How they get it. Iron ore enrichment

Iron ore is the main raw material for the metallurgical industry around the world. Its market, to one degree or another, influences the economy of different states. Today, iron ore resources are mined in more than 50 countries, including the Russian Federation. She confidently holds her position in the permanent five world leaders. Together they supply up to 80% of this raw material to the world market.

Iron ore deposits in Russia

Iron ore resources are distributed unevenly across the territory of the Russian state. More than half of all reserves belong to Precambrian sedimentary ores. They are represented by red, brown, magnetic iron ore of different quality. And only 12% of them are high quality ores, where the iron content is at least 60%. It is worth noting that the Russian state is second only to Brazil in terms of iron ore reserves. But at the same time, domestic deposits compared to foreign ones (Australia, India, Brazil) have a lower quality of ores and difficult geological conditions for their development.

Large deposits of iron ore in Russia are located in the Central Federal District. It accounts for about 55% of the total production of raw materials. Sufficiently significant deposits of explored reserves are in Karelia and the Murmansk region, their production is 18%. The Gusevogorskoye deposit in the Sverdlovsk region produces almost 16% of iron ores. The development of the Kuranakh and Garinskoye deposits in the Amur Region, the Kimkanskoye and Kostenginskoye deposits in the Jewish Autonomous Region, and others are also underway.

Kursk magnetic anomaly

Topping the list of iron ore deposits in Russia are the quarries of the Kursk Magnetic Anomaly (KMA). The area of ​​its basin is more than 160 thousand km 2 and includes the territories of the Oryol, Belgorod, Kursk, and Voronezh regions. In terms of iron reserves, which are estimated at billions of tons, this is the largest basin in the world. To date, more than 30 billion tons of rich iron ore have been explored. Its main mass is represented by magnetite quartzites with an iron content of over 40%.

KMA ores are determined by a multicomponent texture. The depth of their occurrence varies from 30 to 650 meters. Commercial mining is mainly carried out in the Kursk and Belgorod regions, where a significant share of ore reserves is concentrated (the Stoilenskoye, Mikhailovskoye, Lebedinskoye and Yakovlevskoye deposits).

Bakchar field

The Bakchar deposit is the most explored part of the West Siberian iron ore basin. It was discovered in the 1960s during the exploration of oil deposits in the Tomsk region and today is one of the largest iron ore deposits in Russia. There are four ore layers on the territory, which in some places merge into a single deposit. Iron ore formations are mainly located at a depth of 190 meters, but to the north, the subsidence reaches up to 300 meters. The content of iron in ores reaches 57% in some places. In enriched ore, the volume of iron increases significantly and reaches 97%. The area of ​​the Bakchar deposit is 16 thousand km 2 .

A characteristic feature of the rich deposit is the presence of associated components of cobalt, titanium, chromium and vanadium, which further increases the value of ores. According to preliminary estimates of the geological study, the predicted reserves of the Bakcharskoye field are estimated at almost 110 billion tons. It should be noted that the ore horizons of this area are heavily watered and this causes difficulties in the exploitation of the deposit.

The largest iron ore deposits in Russia include the Olenegorsk deposit in the Murmansk region, which was discovered in 1932. Most of its raw material base is represented by ferruginous quartzites, the main minerals in which are magnetite and hematite. The presence of iron averages 31%. The ore lies almost to the very surface, but the ore body goes to a depth of more than 800 meters with a length of 32 km. The ores of this deposit are easily enriched, they have a minimum content of harmful impurities, which makes it possible to obtain high-quality metal.

According to the latest estimates, the reserves of the Olenegorsk deposit on the Kola Peninsula amount to 700 million tons of iron ore. The presence of such significant reserves is contained in very deep horizons, which creates the need for additional exploration of the subsoil.

Kovdorskoye field

Due to its geological history, the Kola Peninsula has significant mineral deposits and makes a significant contribution to the Russian economy. The main iron ore deposits in this region began to be developed since 1962, although they were discovered even before the war. The Kovdorskoye iron ore deposit is one of the largest storages of collection raw materials in the state. Here are rare unique minerals that are not found anywhere else.

Kovdor deposits have been developed since 1962, their reserves amount to about 650 million tons of magnetite ores. The width of the ore body is 100-800 meters, and the length stretches for more than a kilometer. Storeroom deposits were explored to a depth of 800 meters. The iron content averages 28-30%. In addition to magnetite concentrate, baddeleyite and apatite concentrates are extracted from the ore.

Kostomuksha field

Another important region with iron ore deposits in Russia is Karelia. There are 26 deposits and about 70 iron ore manifestations of various ore formations here. Of more practical importance are the formations of ferruginous quartzites, which are well developed in the West Karelian mineralogenic zone. The palm belongs to the Kostomuksha field, which is considered the largest in the North-West of Russia. Its ore reserves are over one billion tons with an average iron content of 32%.

The stratum of ferruginous quartzites of the Kostomuksha deposit stretches in a strip of 15.6 km. It includes two deposits at a depth of up to 40 meters - the main and interbedding. The main deposit contains up to 70% of all reserves of the deposit. Magnetite is the dominant ore mineral, phosphorus and sulfur are present from harmful impurities. The ores of the Kostomuksha deposit are easily enriched.

Also, the following iron ore deposits should not be ignored: Korpangskoye (400 million tons of approved reserves), Pudozhgorskoye (projected resources are estimated at 302 million tons) and Koykarskoye (reserves are estimated at almost 3200 thousand tons).

The Republic of Khakassia

Khakassia is home to some of the oldest iron ore deposits in Russia. Its base is represented by the Teysko-Balyksinsky, Abakano-Anzassky and Verkhneabakansky regions.

The Abagas deposits of ore in the area of ​​Kuznetsk Alatau and the Minusinsk depression were discovered in 1933, but their development was started only 50 years later. The dominant mineral here is magnetite, secondary roles are assigned to pyrite, hematite and musketovite. The balance reserves of raw materials total more than 73 million tons.

Near the city of Abaza is the Abakan iron ore deposit. Its deposits are represented by easily enriched skarn-magnetite ores. Balance reserves contain 145 million tons of ore, the average volume of iron is 42-45%. The deposit was explored up to 1300 meters deep.

Kachkanar deposits

The group of iron ore storerooms in the Sverdlovsk region has been known for a long time, but serious exploration began only in the 30s of the last century. It combines two main deposits: Gusevogorskoye and Kachkanarskoye. Deposits of ore minerals are represented by magnetite and contain mainly titanium and vanadium impurities. They lie at great depths and have a very complex development.

The Kachkanar deposits are among the largest iron ore deposits in Russia, they own 70% of the extracted ores in the Urals. The predicted resources are more than 12 billion tons of ore, and the explored reserves are 7 billion tons with an iron content of 16%. When enriching the ore, the volume of iron in the resulting concentrate reaches 61%.

Bakal deposits

The Bakal group of iron ore deposits is located in the Satka district of the Chelyabinsk region. It is concentrated on an area of ​​150 km 2 and has 24 deposits, each of which has several ore bodies. Two types of ores are distinguished at the deposits: siderite (with an iron content of 32%) and brown iron ore (with an iron content of more than 50%). Siderite ores play the leading role in explored and estimated reserves. The main minerals of these deposits are pistomesite and sideroplesite.

The following quarries are in operation at the Bakalsky ore field: Petlinsky, Central, Novobakalsky, Sosnovsky, Siderite, Shuldinsky. The total ore reserve is one billion tons. In terms of the quality of the ores and the amount of iron in them, the Bakalskoye deposit is one of the best iron ore deposits in Russia.

It should be noted that the iron ore industry is one of the few segments of the Russian industry that feels most confident even in times of crisis. The state balance sheet includes 173 iron ore deposits. Their balance reserves, at the current rate of production, will be able to provide ferrous metallurgy for more than 200 years to come.

The content of iron in industrial ores is from 16 to 72%. Among the useful impurities are Ni, Co, Mn, W, Mo, Cr, V, etc., among the harmful ones are S, R, Zn, Pb, As, Cu. iron ores by genesis are divided into, and (see map).

Basic iron ores

Industrial types of iron ores are classified according to the predominant ore mineral. Magnetite ores are composed of magnetite (sometimes magnesian - magnomagnetite, often martitized - turned into hematite in the process of oxidation). They are most characteristic of carbonatite, skarn and hydrothermal deposits. Apatite and baddeleyite are extracted from carbonatite deposits, and cobalt-containing pyrite and non-ferrous metal sulfides are extracted from skarn deposits. A special variety of magnetite ores are complex (Fe-Ti-V) titanomagnetite ores of igneous deposits. Hematite ores, composed mainly of hematite and, to a lesser extent, magnetite, are common in the weathering crust of ferruginous quartzites (martite ores), in skarn, hydrothermal, and volcanogenic-sedimentary ores. Rich hematite ores contain 55-65% Fe and up to 15-18% Mn. Siderite ores are subdivided into crystalline siderite ores and clayey spar iron ore; they are often magnesian (magnosiderites). They are found in hydrothermal, sedimentary and volcanic-sedimentary deposits. The average content of Fe in them is 30-35%. After roasting siderite ores, as a result of removing CO 2, finely porous iron oxide concentrates are obtained containing 1-2%, sometimes up to 10% Mn. In the oxidation zone, siderite ores turn into brown iron ore. Silicate iron ores are composed of ferruginous chlorites (, leptochlorite, etc.), accompanied by iron hydroxides, sometimes. They form sedimentary deposits. The average content of Fe in them is 25-40%. The admixture of sulfur is negligible, phosphorus up to 1%. They often have an oolitic texture. In the weathering crust, they turn into brown, sometimes red (hydrohematite) iron ore. Brown ironstones are composed of iron hydroxides, most often hydrogoethite. They form sedimentary deposits (marine and continental) and weathering crust deposits. Sedimentary ores often have an oolitic texture. The average content of Fe in ores is 30-35%. The brown iron ore of some deposits (Bakalskoye in the USSR, Bilbao in Spain, etc.) contains up to 1-2% Mn or more. Naturally alloyed brown iron ore, formed in the weathering crusts of ultrabasic rocks, contains 32-48% Fe, up to 1% Ni, up to 2% Cr, hundredths of a percent Co, V. Chromium-nickel irons and low-alloy steel are smelted from such ores without additives. ( , ferruginous ) - poor and medium iron content (12-36%) metamorphosed iron ores, composed of thin alternating quartz, magnetite, hematite, magnetite-hematite and siderite interlayers, in places with an admixture of silicates and carbonates. They are distinguished by a low content of harmful impurities (S and R are hundredths of a percent). Deposits of this type usually have unique (over 10 billion tons) or large (over 1 billion tons) ore reserves. Silica is carried out in the weathering crust, and large deposits of rich hematite-martite ores appear.

The largest reserves and volumes of production fall on Precambrian ferruginous quartzites and rich iron ores formed from them, sedimentary brown iron ores, as well as skarn, hydrothermal and carbonatite magnetite ores, are less common.

Iron ore enrichment

There are rich (over 50% Fe) and poor (less than 25% Fe) ores that require. For the qualitative characteristics of rich ores, the content and ratio of non-metallic impurities (slag-forming components), expressed by the basicity coefficient and flint modulus, are important. According to the value of the basicity coefficient (the ratio of the sum of the contents of calcium and magnesium oxides to the sum of silicon oxides and) iron ores and their concentrates are divided into acidic (less than 0.7), self-fluxing (0.7-1.1) and basic (more than 1.1 ). Self-fluxing ores are the best: acidic ores require the introduction of an increased amount of limestone (flux) into the blast-furnace charge compared to basic ones. According to the silicon module (the ratio of silicon oxide to aluminum oxide), the use of iron ores is limited to types of ores with a module below 2. Poor ores that require enrichment include titanomagnetite, magnetite, and also magnetite quartzites with a magnetite Fe content of over 10-20%; martite, hematite and hematite quartzites with Fe content over 30%; siderite, hydrogoethite and hydrogoethite-leptochlorite ores with Fe content over 25%. The lower limit of the total Fe and magnetite content for each deposit, taking into account its scale, mining and economic conditions, is set by the standards.

Ores that require enrichment are divided into easily enriched and difficult enriched, which depends on their mineral composition and textural and structural features. Easily enriched ores include magnetite ores and magnetite quartz, hard-enriched ores include iron ores, in which iron is associated with cryptocrystalline and colloidal formations, when crushed, it is not possible to open ore minerals in them due to their extremely small size and fine germination with non-metallic minerals. The choice of enrichment methods is determined by the mineral composition of ores, their textural and structural features, as well as the nature of non-metallic minerals and the physical and mechanical properties of ores. Magnetite ores are enriched by the magnetic method. The use of dry and wet magnetic separation ensures the production of conditioned concentrates even with a relatively low iron content in the original ore. If there are commercial grades of hematite in ores, along with magnetite, magnetic-flotation (for finely disseminated ores) or magnetic-gravity (for coarsely disseminated ores) enrichment methods are used. If magnetite ores contain industrial quantities of apatite or sulfides, copper and zinc, boron minerals and others, then flotation is used to extract them from magnetic separation waste. The enrichment schemes for titanomagnetite and ilmenite-titanomagnetite ores include multi-stage wet magnetic separation. In order to isolate ilmenite into titanium concentrate, wet magnetic separation waste is enriched by flotation or gravity, followed by magnetic separation in a high-intensity field.

Enrichment schemes for magnetite quartzites include crushing, grinding, and low-field magnetic enrichment. Enrichment of oxidized ferruginous quartzites can be carried out by magnetic (in a strong field), roasting magnetic and flotation methods. For enrichment of hydrogoethite-leptochlorite oolitic brown iron ore, a gravitational or gravitational-magnetic (in a strong field) method is used; studies are also underway to enrich these ores by roasting a magnetic method. Clayey hydrogoethite and (pebble) ores are enriched by washing. Enrichment of siderite ores is usually achieved by roasting. During the processing of ferruginous quartzites and skarn-magnetite ores, concentrates with an Fe content of 62-66% are usually obtained; in conditioned concentrates of wet magnetic separation from apatite-magnetite and magnomagnetite iron ores, not less than 62-64%; for the electrometallurgical processing, concentrates are produced with an Fe content of not less than 69.5%, SiO 2 not more than 2.5%. Concentrates of gravitational and gravitational-magnetic enrichment of oolitic brown iron ore are considered conditioned when the content of Fe is 48-49%; as enrichment methods improve, the requirements for concentrates from ores increase.

Most of the iron ores are used for iron smelting. A small amount serves as natural paints (ocher) and weighting agents for drilling muds.

Iron ore reserves

In terms of iron ore reserves (balance - over 100 billion tons), the CCCP ranks first in the world. The largest iron ore reserves in the USSR are concentrated in Ukraine, in the central regions of the RSFSR, in northern Kazakhstan, in the Urals, in western and eastern Siberia. Of the total amount of explored iron ore reserves, 15% are rich and do not require enrichment, 67% are enriched using simple magnetic schemes, and 18% require complex enrichment methods.

KHP, North Korea and CPB have significant reserves of iron ore, sufficient for the development of their own ferrous metallurgy. see also

In terms of the presence of predicted iron ore reserves, Russia ranks only third, behind Brazil and the United States. The total amount of ore in the Russian Federation is estimated at about 120.9 billion tons. If we consider the reliability of "intelligence data", then the reserves (category P1) are most accurately determined at 92.4 billion tons, the probability of extraction in full at 16.2 billion tons (category P2) is slightly less likely and the probability of extraction of explored ore is 2.4 billion tons (category P3). The average iron content is 35.7%. The main part of the resources is concentrated on the KMA (Kursk Magnetic Anomaly), located in the European part of Russia. Of lesser importance are deposits located in Siberia, in the Far East.

Distribution of ore reserves in Russia

The share of high-quality ore that does not require enrichment, with an iron content of at least 60% in Russia is almost 12.4%. Basically, the ores are medium and poor, with an iron content in the range of 16-40%. However, only Australia has large reserves of rich ores in the world. 72% of Russian reserves are classified as profitable.

Today in the Russian Federation there are 14 largest deposits. Of these, 6 are located in the region of the anomaly (i.e., more than half), which provides 88% of the development of iron ores. The State Balance of the Russian Federation has 198 fields on its books, 19 of which have off-balance reserves. The main iron ore mining sites, in descending order (by volume of minerals mined):
- Mikhailovskoye deposit (in the Kursk region);
- m. Gusevgorskoye (in the Sverdlovsk region);
- m. Lebedinskoe (in the Belgorod region);
- m. Stoilenskoe (in the Belgorod region);
- Cape Kostomukshskoe (Karelia);
- m. Stoylo-Lebedinskoe (in the Belgorod region);
- m. Kovdorskoye (in the Murmansk region);
- m. Rudnogorskoe (in the Irkutsk region);
- m. Korobkovskoe (in the Belgorod region);
- Cape Olenegorskoye (in the Murmansk region);
- m. Sheregeshevskoe (in the Kemerovo region);
- m. Tashtagolskoe (in the Kemerovo region);
- m. Abakanskoye (Khakassia);
- m. Yakovlevskoe (in the Belgorod region).

Over the past decade, the Russian Federation has seen an increase in iron ore production. The average annual growth is about 4%. However, there is something to strive for: the share of Russian ore in global production is less than 5.6%. Basically, all ore in Russia is mined at KMA (54.6%). In Karelia and the Murmansk region, the volume is 18% of the total production, in the Sverdlovsk region, 16% of ores are issued “on the mountain”.

Iron ore began to be mined by man many centuries ago. Even then, the advantages of using iron became obvious.

Finding mineral formations containing iron is quite easy, as this element makes up about five percent of the earth's crust. Overall, iron is the fourth most abundant element in nature.

It is impossible to find it in its pure form, iron is contained in a certain amount in many types of rocks. Iron ore has the highest iron content, the extraction of metal from which is the most economically profitable. The amount of iron contained in it depends on its origin, the normal proportion of which is about 15%.

Chemical composition

The properties of iron ore, its value and characteristics directly depend on its chemical composition. Iron ore may contain varying amounts of iron and other impurities. Depending on this, there are several types of it:

  • very rich when the iron content in ores exceeds 65%;
  • rich, the percentage of iron in which varies from 60% to 65%;
  • medium, from 45% and above;
  • poor, in which the percentage of useful elements does not exceed 45%.

The more side impurities in the composition of iron ore, the more energy is needed for its processing, and the less efficient is the production of finished products.

The composition of the rock may be a combination of various minerals, waste rock and other impurities, the ratio of which depends on its deposit.

Magnetic ores are distinguished by the fact that they are based on an oxide that has magnetic properties, but with strong heating they are lost. The amount of this type of rock in nature is limited, but the iron content in it may not be inferior to red iron ore. Outwardly, it looks like solid crystals of black and blue.

Spar iron ore is an ore rock based on siderite. Very often it contains a significant amount of clay. This type of rock is relatively hard to find in nature, which, given the small amount of iron content, makes it rarely used. Therefore, it is impossible to attribute them to industrial types of ores.

In addition to oxides, other ores based on silicates and carbonates are found in nature. The amount of iron content in the rock is very important for its industrial use, but the presence of useful by-products such as nickel, magnesium, and molybdenum is also important.

Application industries

The scope of iron ore is almost completely limited to metallurgy. It is used mainly for the smelting of pig iron, which is mined using open-hearth or converter furnaces. Today, cast iron is used in various spheres of human activity, including in most types of industrial production.

Various iron-based alloys are used to no lesser extent - steel has found the widest application due to its strength and anti-corrosion properties.

Cast iron, steel, and various other iron alloys are used in:

  1. Mechanical engineering, for the production of various machine tools and apparatus.
  2. Automotive industry, for the manufacture of engines, housings, frames, as well as other components and parts.
  3. Military and missile industries, in the production of special equipment, weapons and missiles.
  4. Construction, as a reinforcing element or erection of load-bearing structures.
  5. Light and food industry, as containers, production lines, various units and devices.
  6. Mining industry, as special machinery and equipment.

Iron ore deposits

The world's iron ore reserves are limited in quantity and location. The areas of accumulation of ore reserves are called deposits. Today, iron ore deposits are divided into:

  1. Endogenous. They are characterized by a special location in the earth's crust, usually in the form of titanomagnetite ores. The forms and locations of such inclusions are varied, they can be in the form of lenses, layers located in the earth's crust in the form of deposits, volcano-like deposits, in the form of various veins and other irregular shapes.
  2. Exogenous. This type includes deposits of brown iron ore and other sedimentary rocks.
  3. Metamorphogenic. Which include quartzite deposits.

Deposits of such ores can be found throughout our planet. The largest number of deposits is concentrated on the territory of the post-Soviet republics. Especially Ukraine, Russia and Kazakhstan.

Countries such as Brazil, Canada, Australia, the USA, India and South Africa have large iron reserves. At the same time, almost every country on the globe has its own developed deposits, in case of a shortage of which, the breed is imported from other countries.

Enrichment of iron ores

As stated, there are several types of ores. The rich can be processed immediately after being extracted from the earth's crust, others must be enriched. In addition to the beneficiation process, ore processing includes several stages, such as sorting, crushing, separation and agglomeration.

To date, there are several main ways of enrichment:

  1. Flushing.

It is used to clean ores from side impurities in the form of clay or sand, which are washed out using high-pressure water jets. This operation allows you to increase the amount of iron content in poor ore by about 5%. Therefore, it is used only in combination with other types of enrichment.

  1. Gravity cleaning.

It is carried out using special types of suspensions, the density of which exceeds the density of the waste rock, but is inferior to the density of iron. Under the influence of gravitational forces, the side components rise to the top, and the iron sinks to the bottom of the suspension.

  1. magnetic separation.

The most common enrichment method, which is based on a different level of perception of magnetic forces by the components of the ore. Such separation can be carried out with dry rock, wet rock, or in an alternate combination of its two states.

For the processing of dry and wet mixtures, special drums with electromagnets are used.

  1. Flotation.

For this method, crushed ore in the form of dust is lowered into water with the addition of a special substance (flotation agent) and air. Under the action of the reagent, iron joins the air bubbles and rises to the surface of the water, and the waste rock sinks to the bottom. Components containing iron are collected from the surface in the form of foam.

Today it is difficult to imagine life without steel, from which many things around us are made. The basis of this metal is iron obtained by smelting ore. Iron ore differs in origin, quality, method of extraction, which determines the feasibility of its extraction. Also, iron ore is distinguished by its mineral composition, the percentage of metals and impurities, as well as the usefulness of the additives themselves.

Iron as a chemical element is part of many rocks, however, not all of them are considered raw materials for mining. It all depends on the percentage composition of the substance. Specifically, iron formations are called mineral formations in which the volume of useful metal makes its extraction economically feasible.

Such raw materials began to be mined 3,000 years ago, since iron made it possible to produce better durable products in comparison with copper and bronze (see). And already at that time, the craftsmen who had smelters distinguished the types of ore.

Today, the following types of raw materials are mined for further metal smelting:

  • Titanium-magnetite;
  • Apatite-magnetite;
  • Magnetite;
  • Magnetite-hematite;
  • Goethite-hydrogoethite.

Iron ore is considered rich if it contains at least 57% iron. But, developments can be considered appropriate at 26%.

Iron in the composition of the rock is more often in the form of oxides, the remaining additives are silica, sulfur and phosphorus.

All currently known types of ores were formed in three ways:

  • igneous. Such ores were formed as a result of exposure to the high temperature of magma or ancient volcanic activity, that is, the remelting and mixing of other rocks. Such minerals are hard crystalline minerals with a high percentage of iron. Ore deposits of igneous origin are usually associated with old mountain building zones where molten material came close to the surface.

The process of formation of igneous rocks is as follows: a melt of various minerals (magma) is a very fluid substance, and when cracks form at faults, it fills them, cooling down and acquiring a crystalline structure. This is how layers with magma frozen in the earth's crust were formed.

  • metamorphic. This is how sedimentary types of minerals are transformed. The process is as follows: when moving individual sections of the earth's crust, some of its layers containing the necessary elements fall under the overlying rocks. At depth, they are subject to the high temperature and pressure of the upper layers. During millions of years of such exposure, chemical reactions occur here that transform the composition of the source material, crystallization of the substance. Then, in the process of the next movement, the rocks are closer to the surface.

Typically, iron ore of this origin is not too deep and has a high percentage of useful metal composition. For example, as a bright example - magnetic iron ore (up to 73-75% iron).

  • sedimentary. The main "workers" of the process of ore formation are water and wind. Destroying rock layers and moving them to lowlands, where they accumulate in layers. Plus, water, as a reagent, can modify the source material (leach). As a result, brown iron ore is formed - a crumbly and loose ore containing from 30% to 40% iron, with a large number of various impurities.

Raw materials due to various ways of formation are often mixed in layers with clays, limestones and igneous rocks. Sometimes deposits of different origin can be mixed in one field. But most often one of the listed types of breed prevails.

Having established by geological exploration an approximate picture of the processes taking place in a particular area, they determine the possible places with the occurrence of iron ores. As, for example, the Kursk magnetic anomaly, or the Krivoy Rog basin, where, as a result of magmatic and metamorphic influences, types of iron ore valuable in industrial terms were formed.

Iron ore mining on an industrial scale

Mankind began to extract ore a very long time ago, but most often it was low-quality raw materials with significant impurities of sulfur (sedimentary rocks, the so-called "swamp" iron). The scale of development and smelting constantly increased. Today, a whole classification of various deposits of ferruginous ores has been built.

The main types of industrial deposits

All ore deposits are divided into types depending on the origin of the rock, which in turn makes it possible to distinguish the main and secondary iron ore regions.

Main types of commercial iron ore deposits

These include the following deposits:

  • Deposits of various types of iron ore (ferruginous quartzites, magnetic iron ore), formed by a metamorphic method, which makes it possible to extract very rich ores on them. Typically, deposits are associated with the most ancient processes of formation of rocks of the earth's crust and lie on formations called shields.

The Crystal Shield is a large, curved lens formation. It consists of rocks formed at the stage of formation of the earth's crust 4.5 billion years ago.

The best-known deposits of this type are: the Kursk magnetic anomaly, the Krivoy Rog basin, Lake Superior (USA/Canada), Hamersley province in Australia, and the Minas Gerais iron ore region in Brazil.

  • Deposits of reservoir sedimentary rocks. These deposits were formed as a result of the settling of iron-rich compounds that are present in the composition of minerals destroyed by wind and water. A striking example of iron ore in such deposits is brown iron ore.

The most famous and large deposits are the Lorraine basin in France and the Kerch on the peninsula of the same name (Russia).

  • Skarn deposits. Usually the ore is of igneous and metamorphic origin, the layers of which, after formation, were displaced at the time of the formation of mountains. That is, iron ore, located in layers at a depth, was crumpled into folds and moved to the surface during the movement of lithospheric plates. Such deposits are located more often in folded areas in the form of layers or pillars of irregular shape. Formed by magma. Representatives of such deposits: Magnitogorsk (Urals, Russia), Sarbayskoye (Kazakhstan), Iron Springs (USA) and others.
  • Titanomagnetite deposits of ores. Their origin is igneous, they are most often found at outcrops of ancient bedrocks - shields. These include basins and deposits in Norway, Canada, Russia (Kachkanarskoye, Kusinskoye).

Minor deposits include: apatite-magnetite, magno-magnetite, siderite, ferromanganese deposits developed in Russia, Europe, Cuba and others.

Iron ore reserves in the world - leading countries

Today, according to various estimates, deposits with a total volume of 160 billion tons of ore have been explored, from which about 80 billion tons of metal can be obtained.

The US Geological Survey presents data according to which Russia and Brazil account for about 18% of the world's iron ore reserves.

In terms of iron reserves, the following leading countries can be distinguished

The picture of world ore reserves is as follows

Most of these countries are also the largest exporters of iron ore. In general, the volume of raw materials sold is about 960 million tons per year. The largest importers are Japan, China, Germany, South Korea, Taiwan, France.

Typically, private companies are engaged in the extraction and sale of raw materials. For example, the largest in our country, Metallinvest and Evrazholding, producing a total of about 100 million tons of iron ore products.

According to the same US Geological Survey, mining and production volumes are constantly growing, about 2.5-3 billion tons of ore are mined per year, which reduces its value on the world market.

The markup for 1 ton today is about $40. The record price was fixed in 2007 - $180/ton.

How is iron ore mined?

Seams of iron ore lie at different depths, which determines its extraction methods from the bowels.

Career way. The most common quarrying method is used when deposits are found at a depth of about 200-300 meters. The development takes place through the use of powerful excavators and rock crushing plants. After that, it is loaded for transportation to processing plants.

mine method. The pit method is used for deeper layers (600-900 meters). Initially, the mine site is pierced, from which drifts are developed along the seams. From where the crushed rock is fed "to the mountain" with the help of conveyors. Ore from the mines is also sent to processing plants.

Downhole hydraulic mining. First of all, for downhole hydraulic production, a well is drilled to the rock formation. After that, pipes are brought into the target, ore is crushed with a powerful pressure of water with further extraction. But this method today has a very low efficiency and is used quite rarely. For example, 3% of raw materials are extracted in this way, and 70% by mines.

After mining, the iron ore material must be processed to obtain the main raw material for smelting metal.

Since there are many impurities in the composition of the ores, in addition to the necessary iron, in order to obtain the maximum useful yield, it is necessary to clean the rock by preparing the material (concentrate) for smelting. The whole process is carried out at mining and processing plants. For various types of ores, their own methods and methods of purification and removal of unnecessary impurities are applied.

For example, the technological chain of enrichment of magnetic iron ore is as follows:

  • Initially, the ore goes through the crushing stage in crushing plants (for example, jaw crushers) and is fed by a belt conveyor to separation stations.
  • Using electromagnetic separators, the pieces of magnetic iron ore are separated from waste waste rock.
  • After that, the ore mass is transported to the next crushing.
  • The crushed minerals are moved to the next cleaning station, the so-called vibrating sieves, here the useful ore is sifted, separating from the light unnecessary rock.
  • The next stage is the fine ore hopper, in which small particles of impurities are separated by vibrations.
  • Subsequent cycles include the next addition of water, crushing and passing the ore mass through slurry pumps, which remove unnecessary sludge (waste rock) along with the liquid, and again crushing.
  • After repeated cleaning with pumps, the ore enters the so-called screen, which once again cleans the minerals using the gravitational method.
  • The repeatedly purified mixture enters the dehydrator, which removes water.
  • The drained ore again gets to the magnetic separators, and only then to the gas-liquid station.

Brown iron ore is purified according to somewhat different principles, but the essence of this does not change, because the main task of enrichment is to obtain the purest raw materials for production.

The enrichment results in iron ore concentrate used in smelting.

What is made from iron ore - the use of iron ore

It is clear that iron ore is used to obtain metal. But, two thousand years ago, metallurgists realized that in its pure form, iron is a rather soft material, products from which are slightly better than bronze. The result was the discovery of an alloy of iron and carbon - steel.

Carbon for steel plays the role of cement, strengthening the material. Typically, such an alloy contains from 0.1 to 2.14% carbon, and more than 0.6% is already high-carbon steel.

Today, a huge list of products, equipment and machines is made from this metal. However, the invention of steel was associated with the development of the weapon industry, in which the craftsmen tried to obtain a material with strong characteristics, but at the same time, with excellent flexibility, malleability, and other technical, physical and chemical characteristics. Today, high-quality metal has other additives that alloy it, adding hardness and wear resistance.

The second material that is produced from iron ore is cast iron. It is also an alloy of iron with carbon, which contains more than 2.14%.

For a long time, cast iron was considered a useless material, which was obtained either by violating the technology of steel smelting, or as a by-product that settles at the bottom of smelting furnaces. Basically, it was thrown away, it cannot be forged (brittle and practically not ductile).

Before the advent of artillery, they tried to attach cast iron in the economy in various ways. For example, in construction, foundation blocks were made from it, coffins were made in India, and in China, coins were originally minted. The advent of cannons made it possible to use cast iron for casting cannonballs.

Today, cast iron is used in many industries, especially in mechanical engineering. Also, this metal is used to produce steel (open-hearth furnaces and the Bessmer method).

With the growth of production, more and more materials are required, which contributes to the intensive development of deposits. But developed countries consider it more expedient to import relatively inexpensive raw materials, reducing the volume of their own production. This allows the main exporting countries to increase the production of iron ore with its further enrichment and sale as a concentrate.