Name ore. Types of iron ores - a general characteristic of iron ore. Red, brown, yellow, black iron ore

22.04.2020

Iron ore is the main raw material for the world metallurgical industry. The economy of different countries largely depends on the market for this mineral, so the development of mines is given increased attention all over the world.

Ore: definition and features

Ores are rocks that are used to process and extract the metals they contain. The types of these minerals differ in origin, chemical content, concentration of metals and impurities. The chemical composition of the ore contains various oxides, hydroxides and carbonic salts of iron.

Interesting! Ore has been in demand in the economy since ancient times. Archaeologists managed to find out that the manufacture of the first iron objects dates back to the 2nd century BC. BC. For the first time this material was used by the inhabitants of Mesopotamia.

Iron is a common chemical element in nature. Its content in the earth's crust is about 4.2%. But in its pure form, it is almost never found, most often in the form of compounds - in oxides, iron carbonates, salts, etc. Iron ore is a combination of minerals with a significant amount of iron. In the national economy, the use of ores containing more than 55% of this element is considered economically justified.

What is made from ore

iron ore industry— the metallurgical industry, which specializes in the extraction and processing of iron ore. The main purpose of this material today is the production of iron and steel.

All products made from iron can be divided into groups:

Pig iron with high carbon concentration (above 2%).
Cast iron.
Steel ingots for the manufacture of rolled products, reinforced concrete and steel pipes.
Ferroalloys for steel smelting.

What is ore for?

The material is used for smelting iron and steel. Today there is practically no industrial sector that does without these materials.

Cast iron It is an alloy of carbon and iron with manganese, sulfur, silicon and phosphorus. Pig iron is produced in blast furnaces, where the ore is separated from iron oxides at high temperatures. Almost 90% of the iron produced is marginal and is used in steel smelting.

Various technologies are used:

electron-beam smelting to obtain pure high-quality material;
vacuum processing;
electro-slag remelting;
steel refining (removal of harmful impurities).

The difference between steel and cast iron is the minimum concentration of impurities. For purification, oxidative smelting in open-hearth furnaces is used.

The highest quality steel is smelted in electric induction furnaces at extremely high temperatures.

Ore differs in the concentration of the element contained in it. It is enriched (with a concentration of 55%) and poor (from 26%). Poor ores should be used in production only after enrichment.

By origin, the following types of ores are distinguished:

Magmatogenic (endogenous) - formed under the influence of high temperature;
Surface - the settled remains of the element at the bottom of sea basins;
Metamorphogenic - obtained under the influence of extremely high pressure.

The main compounds of minerals with iron content:

Hematite (red iron ore). The most valuable source of iron with an element content of 70% and with a minimum concentration of harmful impurities.
Magnetite. A chemical element with a metal content of 72% or more is distinguished by high magnetic properties and is mined at magnetic iron ore.
Siderite (iron carbonate). There is a high content of waste rock, the iron itself in it is about 45-48%.
Brown ironstones. A group of aqueous oxides with a low percentage of iron, with impurities of manganese and phosphorus. An element with such properties is distinguished by good reducibility and porous structure.

The type of material depends on its composition and the content of additional impurities. The most common red iron ore with a high percentage of iron can be found in a different state - from very dense to dusty.

Brown ironstones have a loose, slightly porous structure of brown or yellowish color. Such an element often needs to be enriched, while it is easily processed into ore (high-quality cast iron is obtained from it).

Magnetic iron ore is dense and granular in structure and looks like crystals interspersed in the rock. The shade of the ore is a characteristic black-blue.

How ore is mined

Iron ore mining is a complex technical process that involves diving into the earth's interior in order to search for minerals. To date, there are two ways to extract ore: open and closed.

Open (quarry method) is the most common and safest option compared to closed technology. The method is relevant for those cases when there are no hard rocks in the working area, and there are no settlements or engineering systems nearby.

First, a quarry is dug out up to 350 meters deep, after which iron is collected and removed from the bottom by large machines. After mining, the material is transported by diesel locomotives to steel and iron factories.

Quarries are dug by excavators, but such a process takes a lot of time. As soon as the machine reaches the first layer of the mine, the material is submitted for examination to determine the percentage of iron content and the feasibility of further work (if the percentage is above 55%, work in this area continues).

Interesting! Compared to the closed method, mining in quarries costs half as much. This technology does not require the development of mines or the creation of tunnels. At the same time, the efficiency of work in open pits is several times higher, and material losses are five times less.

Closed mining method

Mine (closed) ore mining is used only if it is planned to preserve the integrity of the landscape in the area where ore deposits are being developed. Also, this method is relevant for work in mountainous areas. In this case, a network of tunnels is created underground, which leads to additional costs - the construction of the mine itself and the complex transportation of metal to the surface. The main drawback is the high risk to the lives of workers, the mine can collapse and block access to the surface.

Where is the ore mined

The extraction of iron ore is one of the leading areas of the economic complex of the Russian Federation. But despite this, Russia's share in world ore production is only 5.6%. World reserves are about 160 billion tons. The volume of pure iron reaches 80 billion tons.

countries rich in ores

The distribution of fossils by country is as follows:

Russia - 18%;
Brazil - 18%;
Australia - 13%;
Ukraine - 11%;
China - 9%;
Canada - 8%;
USA - 7%;
other countries - 15%.

Significant deposits of iron ore are noted in Sweden (the cities of Falun and Gellivar). In America, a large amount of ore has been discovered in the state of Pennsylvania. In Norway, metal is mined in Persberg and Arendal.

Ores of Russia

The Kursk magnetic anomaly is a large iron ore deposit in the Russian Federation and in the world, in which the volume of crude metal reaches 30,000 million tons.

Interesting! Analysts note that the scale of mining at the KMA mines will continue until 2020, and then there will be a decline.

The mine area of the Kola Peninsula is 115,000 sq. km. Iron, nickel, copper ores, cobalt and apatite are mined here.

The Ural Mountains are also among the largest ore deposits in the Russian Federation. The main area of development is Kachkanar. The volume of ore minerals is 7000 million tons.

To a lesser extent, metal is mined in the West Siberian basin, in Khakassia, the Kerch basin, in Zabaikalsk and the Irkutsk region.

In addition to the well-known oil and gas, there are other equally important minerals. These include ores that are mined for ferrous and by processing. The presence of ore deposits is the wealth of any country.

What are ores?

Each of the natural sciences answers this question in its own way. Mineralogy defines ore as a set of minerals, the study of which is necessary to improve the processes of extracting the most valuable of them, and chemistry studies the elemental composition of ore in order to identify the qualitative and quantitative content of valuable metals in it.

Geology considers the question: "what are ores?" from the point of view of the expediency of their industrial use, since this science studies the structure and processes occurring in the bowels of the planet, the conditions for the formation of rocks and minerals, and the exploration of new mineral deposits. They are areas on the surface of the Earth, on which, due to geological processes, a sufficient amount of mineral formations has accumulated for industrial use.

Ore formation

Thus, to the question: “what are ores?” The most complete answer is this. Ore is a rock with an industrial content of metals in it. Only in this case it has value. Metal ores are formed when the magma that contains their compounds cools. At the same time, they crystallize, distributing according to their atomic weight. The heaviest ones settle to the bottom of the magma and stand out in a separate layer. Other minerals form rocks, and the hydrothermal fluid left from the magma spreads through the voids. The elements contained in it, solidifying, form veins. Rocks, being destroyed under the influence of natural forces, are deposited at the bottom of reservoirs, forming sedimentary deposits. Depending on the composition of rocks, various ores of metals are formed.

Iron ores

The types of these minerals vary greatly. What are ores, in particular, iron? If the ore contains enough metal for industrial processing, it is called iron ore. They differ in origin, chemical composition, as well as the content of metals and impurities that may be useful. As a rule, these are associated non-ferrous metals, for example, chromium or nickel, but there are also harmful ones - sulfur or phosphorus.

The chemical composition is represented by its various oxides, hydroxides or carbonic salts of iron oxide. The developed ores include red, brown and magnetic iron ore, as well as iron luster - they are considered the richest and contain more than 50% metal. The poor include those in which the useful composition is less - 25%.

Composition of iron ore

Magnetic iron ore is iron oxide. It contains more than 70% pure metal, however, it occurs in deposits together with and sometimes with zinc blende and other formations. is considered the best of the used ores. Iron shine also contains up to 70% iron. Red iron ore - iron oxide - one of the sources of extraction of pure metal. And brown analogues have up to 60% metal content and are found with impurities, sometimes harmful. They are hydrous iron oxide and accompany almost all iron ores. They are also convenient for the ease of mining and processing, but the metal obtained from this type of ore is of low quality.

According to the origin of iron ore deposits, they are divided into three large groups.

Endogenous, or magmatogenic. Their formation is due to geochemical processes that took place in the depths of the earth's crust, magmatic phenomena.
Exogenous, or surface, deposits were created as a result of processes occurring in the near-surface zone of the earth's crust, that is, at the bottom of lakes, rivers, and oceans.
Metamorphogenic deposits were formed at a sufficient depth from the earth's surface under the influence of high pressure and the same temperatures.

Iron ore reserves in the country

Russia is rich in various deposits. The largest in the world is containing almost 50% of all world reserves. In this region, it was noted already in the 18th century, but the development of deposits began only in the 30s of the last century. The ore reserves in this basin are high in pure metal, they are measured in billions of tons, and mining is carried out by an open or underground method.

The Bakchar iron ore deposit, which is one of the largest in the country and the world, was discovered in the 60s of the last century. The ore reserves in it with a concentration of pure iron up to 60% are about 30 billion tons.

In the Krasnoyarsk Territory there is the Abagasskoye deposit - with magnetite ores. It was discovered back in the 30s of the last century, but its development began only half a century later. In the Northern and Southern zones of the basin, mining is carried out by open-pit mining, and the exact amount of reserves is 73 million tons.

Discovered in 1856, the Abakan iron ore deposit is still active. At first, the development was carried out in an open way, and from the 60s of the XX century - by an underground method at a depth of up to 400 meters. The content of pure metal in the ore reaches 48%.

Nickel ores

What is nickel ores? Mineral formations that are used for the industrial production of this metal are called nickel ores. There are sulfide copper-nickel ores with a pure metal content of up to four percent and silicate nickel ores, the same indicator of which is up to 2.9%. The first type of deposits is usually of the igneous type, and silicate ores are found in the weathering crust.

The development of the nickel industry in Russia is associated with the development of their location in the Middle Urals in the middle of the 19th century. Almost 85% of sulphide deposits are concentrated in the Norilsk region. The deposits in Taimyr are the largest and most unique in the world in terms of richness of reserves and variety of minerals, they contain 56 elements of the periodic table. In terms of the quality of nickel ores, Russia is not inferior to other countries, the advantage is that they contain additional rare elements.

About ten percent of nickel resources are concentrated in sulfide deposits on the Kola Peninsula, and silicate deposits are being developed in the Middle and Southern Urals.

The ores of Russia are characterized by the quantity and variety necessary for industrial applications. However, at the same time, they are distinguished by complex natural conditions of extraction, uneven distribution on the territory of the country, mismatch between the region where resources are located and the population density.

Iron ore is a mineral formation of a natural nature, which has in its composition iron compounds accumulated in such a volume that is sufficient for its economic extraction. Of course, iron is present in all rocks. But iron ores are precisely those ferruginous compounds that are so rich in this substance that they allow the industrial extraction of metallic iron.

Types of iron ores and their main characteristics

All iron ores are very different in their mineral composition, the presence of harmful and beneficial impurities. The conditions of their formation and, finally, the content of iron.

The main materials that are classified as ore can be divided into several groups:

Iron oxides, which include hematite, martite, magnetite.
Iron hydroxides - hydrogoethite and goethite;
Silicates - thuringite and chamosite;
Carbonates - sideroplesite and siderite.

In industrial iron ores, iron is contained in various concentrations - from 16 to 72%. Useful impurities contained in iron ores include: Mn, Ni, Co, Mo, etc. There are also harmful impurities, which include: Zn, S, Pb, Cu, etc.

Iron ore deposits and mining technology

By genesis, existing iron ore deposits are divided into:

Endogenous. They can be igneous, which are inclusions of titanomagnetite ores. There may also be carbonatite inclusions. In addition, there are lenticular, sheet-like skarn-magnetite deposits, volcano-sedimentary sheet deposits, hydrothermal veins, as well as irregularly shaped ore bodies.
Exogenous. These mainly include brown-iron and siderite sedimentary reservoir deposits, as well as deposits of thuringite, chamosite and hydrogoethite ores.
Metamorphogenic - these are deposits of ferruginous quartzites.

The maximum volumes of ore mining are provoked by significant reserves and fall on Precambrian ferruginous quartzites. Sedimentary brown iron ores are less common.

When mining, rich and requiring enrichment of ores are distinguished. The iron ore mining industry also carries out its pre-processing: sorting, crushing and the aforementioned enrichment, as well as agglomeration. The ore mining industry is called the iron ore industry and is the raw material base for ferrous metallurgy.

Application industries

Iron ore is the main raw material for iron production. It enters the open-hearth or converter production, as well as for the reduction of iron. From iron, as you know, they produce a wide variety of products, as well as from cast iron. The following industries need these materials:

Mechanical engineering and metalworking;
Automotive industry;
Rocket industry;
military industry;
Food and light industry;
Building sector;
Extraction of oil and gas and their transportation.

One of the most important minerals, along with fuel, are the so-called ore minerals. Ore is a rock that contains large quantities of certain elements or their compounds (substances). The most used types of ores are iron, copper and nickel.

Iron ore is an ore that contains iron in such quantities and chemical compounds that its extraction is possible and economically profitable. The most important minerals are: magnetite, magnomagnetite, titanomagnetite, hematite and others. Iron ores differ in their mineral composition, iron content, useful and harmful impurities, formation conditions and industrial properties.

Iron ores are divided into rich (more than 50% iron), ordinary (50-25%) and poor (less than 25% iron). Depending on the chemical composition, they are used for iron smelting in its natural form or after enrichment. Iron ores used to make steel must contain certain substances in the required proportions. The quality of the resulting product depends on this. Some chemical elements (other than iron) can be extracted from the ore and used for other purposes.

Iron ore deposits are divided by origin. Usually there are 3 groups: igneous, exogenous and metamorphogenic. They can be further subdivided into several groups. Magmatogenic are formed mainly when exposed to various compounds of high temperatures. Exogenous deposits arose in river valleys during the deposition of sediments and weathering of rocks. Metamorphic deposits are pre-existing sedimentary deposits that have been transformed under conditions of high pressures and temperatures. The largest amount of iron ore is concentrated in Russia.

The Kursk magnetic anomaly is the most powerful iron ore basin in the world. Ore deposits on its territory are estimated at 200-210 billion tons, which is about 50% of the iron ore reserves on the planet. It is located mainly on the territory of the Kursk, Belgorod and Oryol regions.

Nickel ore is an ore containing the chemical element nickel in such quantities and chemical compounds that its extraction is not only possible, but also economically viable. Usually these are deposits of sulfide (nickel content 1-2%) and silicate (nickel content 1-1.5%) ores. The most important include the most common minerals: sulfides, hydrous silicates and nickel chlorites.

Copper ores are natural mineral formations, the copper content of which is sufficient for the economically profitable extraction of this metal. Of the many known minerals containing copper, about 17 are used on an industrial scale: native copper, bornite, chalcopyrite (copper pyrites) and others. The following types of deposits are of industrial importance: copper pyrite, skarn copper-magnetite, copper-titanomagnetite and copper-porphyry.

They lie among the volcanic rocks of the ancient period. Numerous terrestrial and underwater volcanoes were active during this period. Volcanoes emitted sulfurous gases and hot waters saturated with metals - iron, copper, zinc and others. Of these, on the seabed and in the underlying rocks, ores were deposited, consisting of iron, copper and zinc sulfides, called pyrites. The main mineral of sulfide ores is pyrite, or sulfur pyrite, which makes up the predominant part (50–90%) of the volume of sulfide ores.

Most of the mined nickel is used for the production of heat-resistant, structural, tool, stainless steels and alloys. A small part of nickel is spent on the production of nickel and copper-nickel rolled products, for the manufacture of wire, tapes, various equipment for industry, as well as in aviation, rocket science, in the manufacture of equipment for nuclear power plants, and in the manufacture of radar instruments. In industry, nickel alloys with copper, zinc, aluminum, chromium and other metals.

, titanium, copper, lead, etc.) there are barite, graphite, asbestos, corundum, phosphate and other similar ores related to non-metallic minerals. More than 80 chemical compounds are extracted from ores and used in the national economy. elements.

There are mono- and polymineral ores, consisting respectively. from one or several minerals. All ores have a complex and often heterogeneous composition. In terms of the ratio of useful (ore) and others that do not have industrial. values, minerals distinguish solid and disseminated ores. The first are preim. from ore minerals; for example, iron ores may consist of almost magnetite alone. In disseminated ores, useful minerals are distributed in the form of the so-called. phenocrysts, to-rye can be 20-60% of the bulk.

R Udu is called simple or complex, if resp. is extracted from it. one or several useful ingredients. Complex ores often contain impurities of rare metals, for example: in bauxites - Ga, La and Sc, in iron ores - V, in titanium - V, Sc, Nb. The presence of impurities of rare elements (V, Ge, Ga, REE, etc.) increases the value of the ore. For example, the extraction of poor titanomagnetite ores is expedient only with the associated extraction of vanadium (Kachkanar type of ores). Harmful impurities impede metallurgical. redistribution of ores (and their concentrates) or degrade the quality of the resulting product. So, in the ilmenite concentrate intended for the production of pigment titanium oxide by the sulfuric acid method, it should contain: Cr 2 O 3 8 0.05%, P 2 O 5 8 0.1%; the processing of iron ores is complicated in the presence of Ti, S, P or As, and when the content of TiO 2 is more than 4%, titanomagnetite is unsuitable for the blast furnace process. For the correct and naib. full utilization of ores requires a detailed study of their elemental and material (in particular, mineral) composition.

Min. the content of valuable components, which is economically feasible for prom. extraction, as well as the permissible max. the content of harmful impurities, called. prom. conditions. They depend on the forms of finding useful components in ores, technol. ways of its extraction and processing. With the improvement of the latter, the assessment of the ores of a particular deposit changes. So, in 1955, iron ore with an iron content of at least 60% was mined in Krivoy Rog, and subsequently, ores containing 25-30% iron began to be used. The higher the value of the metal, the less m.b. reserves of its ores in the deposit and its content in ores is lower (Table 1). This is especially true for rare, radioactive and noble metals. For example, scandium is obtained from ores at a content of approx. 0.002%, gold and platinum at a content of 0.0005%.

The ever-expanding needs of the industry make it necessary to involve all new types of ores in the sphere of production, which have never been used before. The complexity of using traditional ores is increasing.

According to geol. conditions of ore formation are divided into magmatic, exogenous and metamorphogenic (see Minerals). Iron often forms large accumulations (billion tons) of both magmatogenic and exogenous and metamorphogenic origin. Dr. useful components are less common and, as a rule, form prom. accumulations of a limited number of types of ores.

As a result of various geol. processes, ore bodies (clusters of ores) are formed, having decomp. shape and dimensions. According to V. I. Smirnov (1976), the following are distinguished. main forms of ore bodies: 1) isometric, three dimensions of which are close; 2) plate-like, two dimensions (length and width) to-rykh are much larger than the third (power); 3) tubular, in which one dimension (length) is much larger than the other two (power and width); 4) complex shape, having irregular, sharply changing outlines in all dimensions. Forms of ore bodies depend on geol. structures and lithology. composition of host rocks. Syngenetic ores are formed simultaneously with the rocks in which they are located, epigenetic ores, as a result of the penetration of gas and liquid solutions into the rocks.

R Ouds are characterized by a variety of structures and textures. The structure of the ore is determined by the structure of the miner. aggregates, i.e., the shape, size and method of combination of individual grains that make up this aggregate. There are 13 structural groups: uniform-grained, uneven-grained, lamellar, fibrous, zonal, crystallographically oriented, close intergrowth, bordering, substitution, crushing, colloform, spherulitic and detrital. Each group is subdivided into number of species.

The texture of the ore is spaces. the location of the miner. aggregates, to-rye differ from each other in size, shape and composition. Allocate 10 main. texture groups: massive, spotted, banded, veined, spheroidal, kidney-shaped, crushed, hollow, wireframe and loose. Each group has its own types, for example: the spotted one includes two types of textures (taxitic and disseminated), and the banded one includes nine types of textures (actually banded, ribbon, complex, etc.). An analysis of the structures and textures of ores makes it possible to establish the sequence of formation of minerals and the features of the formation of ore bodies.

According to chem. The composition of the predominant minerals distinguish oxide, silicate, sulfide, native, carbonate, phosphate and mixed ores. Thus, characteristic representatives of oxide ores are accumulations of iron minerals (magnetite Fe 3 O 4, hematite Fe 2 O 3) and titanium (ilmenite FeTiO 3, rutile TiO 2); sulfide ores include pyrite FeS 2 , chalcopyrite CuFeS 2 , sphalerite ZnS, galena PbS; Ch. is mined from native ores. arr. Au and Pt. The similarity of geochem. St. in several metals leads to the fact that ores containing them are spatially and genetically related in nature with well-defined mountain complexes.