Iron ore. Metal ores and their classification Composition of iron ore

Man began to mine iron ore at the end of the II millennium BC, having already determined for himself the advantages of iron in comparison with stone. Since then, people began to distinguish between the types of iron ores, although they did not yet have the names that they do today.

In nature, iron is one of the most common elements, and according to various estimates, iron is contained in the earth's crust from four to five percent. It is the fourth most abundant after oxygen, silicon and aluminum.

Iron is not presented in pure form, it is contained in more or less amounts in different kind rocks. And if, according to the calculations of specialists, it is expedient and economically profitable to extract iron from such a rock, it is called iron ore.

Over the past few centuries, during which steel and pig iron are smelted very actively, iron ores have been depleted - after all, more and more metal is required. For example, if in the 18th century, at the dawn of the industrial era, ores could contain 65% iron, now the content of 15 percent of the element in ore is considered normal.

What iron ore is made of.

The composition of the ore includes ore and ore-forming minerals, various impurities and waste rock. The ratio of these components differs from field to field.

Ore material contains the bulk of iron, and waste rock is mineral deposits containing very little or no iron.

Iron oxides, silicates and carbonates are the most common ore minerals in iron ores.

Types of iron ore in terms of iron content and location.

Low iron or separated iron ore, below 20%
Medium iron or sintered ore
Iron containing mass or pellets - rocks with a high iron content, above 55%

Iron ores can be linear - that is, occurring in the places of faults and bends in the earth's crust. They are the richest in iron and contain little phosphorus and sulfur.

Another type of iron ore is flat-like, which is found on the surface of iron-bearing quartzites.

Red, brown, yellow, black iron ore.

The most common type of ore is red iron ore, which is formed by anhydrous iron oxide hematite, which has chemical formula Fe 2 O 3. Hematite contains a very high percentage of iron (up to 70 percent) and few impurities, in particular sulfur and phosphorus.

Red iron ores can be in different physical states - from dense to dusty.

Brown iron ore is an aqueous iron oxide Fe 2 O 3 * nH 2 O. The number n may vary depending on the base that makes up the ore. Most often these are limonites. Brown iron ore, in contrast to red, contains less iron - 25-50 percent. Their structure is loose, porous, and the ore contains many other elements, among which are phosphorus and manganese. Brown iron ore contains a lot of adsorbed moisture, while the waste rock is clayey. This type of ore got its name because of its characteristic brown or yellowish color.

But despite the rather low iron content, due to its easy reducibility, such ore is easy to process. Often high-quality cast iron is smelted from them.

Brown iron ore is most often in need of enrichment.

Magnetic ores are those that are formed by magnetite, which is a magnetic iron oxide Fe 3 O 4. The name suggests that these ores have magnetic properties that are lost when heated.

Magnetic iron ores are less common than red ones. But iron in them can even contain over 70 percent.

By its structure, it can be dense and grainy, it can look like crystals embedded in the rock. The color of magnetite is black and blue.

Another type of ore called spar iron ore. Its ore-bearing component is iron carbonate with a chemical composition of FeCO 3 called siderite. Another name is clay iron ore - if the ore contains a significant amount of clay.

Spar and clay iron ores are found in nature less frequently than other ores and contain relatively little iron and a lot of waste rock. Siderite can be transformed into brown iron ore under the influence of oxygen, moisture and precipitation. Therefore, the deposits look like this: in the upper layers it is brown iron ore, and in the lower layers - spar iron ore.

In addition to the well-known oil and gas, there are other equally important minerals. These include ores that are mined to obtain 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 extraction of the most valuable of them, and chemistry studies the elemental composition of ore in order to reveal 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 is engaged in the study of the structure and processes occurring in the bowels of the planet, the conditions for the formation of rocks and minerals, the exploration of new deposits of minerals. They represent areas on the Earth's surface where, due to geological processes, a sufficient amount of mineral formations has accumulated for industrial use.

Formation of ores

Thus, to the question: "What are ores?" the most complete answer is as follows. Ore is a rock with an industrial metal content. Only then does it have value. Metal ores are formed when the magma, which contains their compounds, cools. At the same time, they crystallize, being distributed according to the value of 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 over from the magma flows through the voids. The elements contained in it, freezing, form veins. Rocks, collapsing under the influence of natural forces, are deposited at the bottom of reservoirs, forming sedimentary deposits. Different metal ores are formed depending on the composition of the rocks.

Iron ore

The types of these minerals vary considerably. What are ores, in particular iron ores? If the ore contains a sufficient amount of metal for industrial processing, it is called iron. They differ in origin, chemical composition, and the content of metals and impurities that can be useful. As a rule, these are accompanying 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 carbonate salts of iron oxide. The mined 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%.

Iron ore composition

Magnetic iron ore is iron oxide. It contains more than 70% pure metal, however, in deposits it is found together with and sometimes with zinc blende and other formations. considered to be the best ore used. Iron luster also contains up to 70% iron. Red iron ore - iron oxide - is one of the sources of the extraction of pure metal. And brown analogs 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 extraction, processing, however, the metal obtained from this type of ore is of low quality.

According to their origin, iron ore deposits are divided into three large groups.

Endogenous, or magmatogenic. Their formation is due to geochemical processes occurring 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, 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 - it contains 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. Ore reserves in this basin with a high content of pure metal, they are measured in billions of tons, and the extraction is carried out by open-pit or underground methods.

The Bakchar iron ore deposit, one of the largest in the country and the world, was discovered in the 60s of the last century. 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, production is carried out open way, and the exact amount of reserves is 73 million tons.

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

Nickel ores

What are 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 index of which is up to 2.9%. The first type of deposits is usually of the magmatic type, and silicate ores are found in the places of 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 sulfide 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.

On the Kola Peninsula, about ten percent of nickel resources are concentrated in sulfide deposits, while silicate deposits are being developed in the Middle and South Urals.

Russian ores are characterized by the amount and variety required for industrial use. However, at the same time, they differ in complex natural conditions production, uneven distribution on the territory of the country, mismatch of the region of resource allocation with population density.

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 fairly easy, since 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. The highest iron content is found in iron ore, 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 in the composition is about 15%.

Chemical composition

The properties of iron ore, its value and characteristics directly depend on its chemical composition. Iron ore can 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 ranges 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 can be a combination of various minerals, waste rock and other by-impurities, the ratio of which depends on its deposit.

Magnetic ores differ in that they are based on an oxide that has magnetic properties, but they are lost with strong heating. 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 color.

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

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

Industries of application

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

Various iron-based alloys are used no less - steel has found the most widespread use due to its strength and anti-corrosion properties.

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

Mechanical engineering, for the production of various machines and apparatus.
Automotive, for the manufacture of engines, casings, frames, as well as other units and parts.
Military and missile industries, in the production of special equipment, weapons and missiles.
Construction, as a reinforcing element or the construction of load-bearing structures.
Light and food industry, as containers, production lines, various units and apparatus.
Extractive 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:

Endogenous. They are characterized by a special arrangement in the earth's crust, usually in the form of titanomagnetite ores. The shapes 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.
Exogenous. This type includes deposits of brown iron ore and other sedimentary rocks.
Metamorphogenic. These include quartzite deposits.

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

Countries such as Brazil, Canada, Australia, USA, India and South Africa have large reserves of iron. Moreover, in almost every country the globe have their own developed deposits, in the event of a shortage of which, the rock is imported from other countries.

Beneficiation of iron ores

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

Today there are several main ways of getting rich:

Flushing.

It is used for cleaning ores from by-impurities in the form of clay or sand, which are washed out with water jets under high pressure... This operation makes it possible to increase the amount of iron content in the lean ore by about 5%. Therefore, it is used only in combination with other types of enrichment.

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, side components rise to the top, and iron falls to the bottom of the suspension.

Magnetic separation.

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

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

Flotation.

For this method, crushed ore in the form of dust is immersed in water with the addition of a special substance (flotation reagent) and air. Under the action of the reagent, iron is attached to air bubbles and rises to the surface of the water, and the waste rock sinks to the bottom. Iron components collect from the surface in the form of foam.

Iron ore Is the main raw material for the global metallurgical industry. The economy largely depends on the market for this mineral. different countries Therefore, the development of mines is receiving 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. V chemical composition ore contains various of its oxides, hydroxides and carbonate iron salts.

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

Iron- a chemical element common in nature. Its content in the crust of the earth is about 4.2%. But in its pure form, it almost never occurs, most often in the form of compounds - in oxides, iron carbonates, salts, etc. Iron ore is a combination of minerals with significant amounts 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 cast iron and steel.

All products made from iron can be divided into groups:

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

What is ore for?

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

Cast iron Is an alloy of carbon and iron with manganese, sulfur, silicon and phosphorus. Pig iron is produced in blast furnaces, where at high temperatures ore is isolated from iron oxides. Almost 90% of the obtained pig iron is limiting and is used in steelmaking.

Various technologies are used:

electron beam smelting for pure, high quality material;
vacuum treatment;
electro-slag remelting;
refining of steel (elimination of harmful impurities).

The difference between steel and cast iron is the minimum concentration of impurities. For cleaning, oxidizing 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 it contains. It can be enriched (with a concentration of 55%) and poor (from 26%). It is advisable to use poor ores in production only after beneficiation.

The following types of ores are distinguished by origin:

Magmatogenic (endogenous) - formed under the influence of high temperature;
Surface - settled remains of the element on 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 a minimum concentration of harmful impurities.
Magnetite. A chemical element with a metal content of 72% is distinguished by high magnetic properties and is mined on magnetic iron ore.
Siderite (iron carbonate). There is a high content of waste rock, iron itself in it is about 45-48%.
Brown iron ore. A group of hydrous oxides with a low percentage of iron, with impurities of manganese and phosphorus. An element with such properties is distinguished by good recoverability and a 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 different states - from very dense to dusty.

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

Magnetic iron ore are dense and granular in structure, looking like crystals embedded in the rock. The shade of the ore is characteristic black and blue.

How ore is mined

The extraction of iron ore is a complex technical process in which immersion into the earth's interior takes place in order to search for minerals. Today, there are two ways of mining ore: open and closed.

Open (career method) is the most common and safest option in comparison with the closed technique. The method is relevant for those cases when there are no hard rocks, and there are no settlements or engineering systems nearby.

First, a quarry is pulled out to a depth of 350 meters, after which iron is collected and removed from the bottom by large machines. After extraction, the material is sent to the steel and cast iron factories in diesel locomotives.

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

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

Closed mining method

Shaft (closed) ore mining is used only if it is planned to preserve the integrity of the landscape in the area where the 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 biggest drawback is high risk for the lives of workers, the mine could collapse and block access to the surface.

Where is the ore mined

Iron ore mining is one of the leading spheres of the economic complex of the Russian Federation. Despite this, the share of Russia in the 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 (cities of Falun and Gellivar). In America, a large amount of ore is found in the state of Pennsylvania. In Norway, the metal is mined in Persberg and Arendali.

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 production of minerals at the mines of the KMA will remain until 2020, in the future there will be a decline.

The area of mines on 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 development area is Kachkanar. The volume of ore resources is 7000 million tons.

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

Man uses in one way or another all the minerals and rocks of the Earth. Ferrous and non-ferrous metals how minerals are part of the earth's crust in the form ore... According to the scientist A. Vinogradova the following elements prevail in the deposits of the earth's crust (their content is given as a percentage): magnesium (2.2), potassium (2.5), sodium (2.8), calcium (3.7), iron (5.5), aluminum (8.5), silicon (27), oxygen (48). These elements are part of the silicates and aluminosilicates that make up the earth's crust.

Iron

Iron Is a common element. Its amount in the earth's crust is calculated in several percent, but iron is extracted from rich ores with a content of at least 25 percent of the metal.

Iron ore

The types of iron deposits are very diverse. Highest value have so-called ferruginous quartzites- thin-striped rocks in which black stripes - iron minerals magnetite - magnetic iron ore and less hematite - hematite- interlayered with ribbons of light quartz... Such deposits contain many billion tons iron ore and are known mainly in the most ancient strata of two and more billion years old! They are developed in ancient crystal shields and platforms. They are widespread in North and South America , in the West Australia, v Africa, v India... The reserves of this type of iron ore are practically unlimited - over 30 trillion tons, a truly astronomical figure! It is assumed that ferruginous quartzites were formed under the action of iron bacteria in ancient basins due to iron supplied in solutions from the surrounding heights, and, perhaps, in hot deep solutions.

Deposition sedimentary iron ore takes place in lakes, seas - modern "natural laboratories". V last years open selection iron nodules(nodules) at the bottom of the oceans. They contain huge reserves of not only iron, but also its attendant manganese, nickel and other elements. The types of iron deposits include the so-called contact or skarn deposits that are located on the border granite rocks and limestone and are formed due to solutions brought from the magma body. Deposits of this type are composed of rich ores. Iron minerals seem to be scarce. The main ones are: magnetite, hematite as well as various varieties brown iron ore, siderite(iron carbonate). These minerals give big variety types of deposits.

Manganese

It is similar to iron in terms of education and technical application. manganese.

Sedimentary ores

It usually accompanies the gland in sedimentary ores and ancient metamorphic deposits... He, like iron, the basis of ferrous metallurgy, used for the production of high-quality steels.

Chromium

It belongs to ferrous metals and chromium... Its main mineral is chromite- forms black solid masses and inclusions of crystals in ultrabasic rocks.

Chromite deposits

Chromite deposits Like the enclosing ultrabasic rock masses, they occur in deep fault zones. Ore-bearing magma came from subcrustal depths, from the mantle. Chromite deposits are known in South West Africa, on the Philippines, on the Cuba, on the Ural... Chromium is used in metallurgical production for imparting special hardness to steel, in the chrome plating of metal surfaces and in the paint industry, it gives the compounds a green color.

The same technical group includes titanium... It is mined from basic igneous rocks in the form of ilmenite and from placers, terrestrial and very widespread on sea beaches and shelves ( Brazil, Australia, India), where titanomagnetite, ilmenite, and rutile serve as its source.

Titanium is used in production special grades of steel... This heat-resistant, lightweight metal.

It is also important vanadium- a frequent companion of titanium in deposits and placers, used for the manufacture extra strong grades of steel used in the production of armor and shells, in the automotive industry, in the nuclear power industry. Everybody is here big role acquire new combinations of elements in alloys. For example, an alloy of vanadium with titanium, niobium, tungsten, zirconium, and aluminum is used in the production of rockets and in nuclear technology. And new composite materials are also prepared from mineral raw materials.

Nickel and cobalt

Nickel and cobalt, also elements of the iron family, are found more often in basic and ultrabasic rocks, especially nickel.

Nickel ore

It forms large deposits in South West Africa, on the Kola Peninsula and in the area Norilsk... These are magmatic deposits. Nickel sulfides crystallized from magmatic melt supplied from the mantle or from hot aqueous solutions. A special type is the residual nickel deposits formed as a result of the weathering of nickel-bearing basic rocks, for example basalts, gabbroids... In this case, oxidized nickel minerals appear in the form of loose greenish masses. The same residual nickel ores enriched with iron, which allows them to be used for the manufacture of iron-nickel alloys. Such deposits are found in Ural, but they are especially widespread in the tropical zone - on the islands Indonesia, on the Philippines where the oxidation of rocks on the surface is intense.

Non-ferrous metals

Are important for industry non-ferrous metals... Many of them geochemically belong to the group of chalcophilic, related to copper (chalcos - copper): copper, lead, zinc, molybdenum, bismuth... In nature, these metals form compounds with gray, sulfides... Minerals of non-ferrous metals were deposited for the most part from hot aqueous solutions; the main ones are for copper chalcopyrite- golden mineral, bornite- a lilac mineral, a constant companion of chalcopyrite, as well as black sooty chalcocite which is found at the top of many copper deposits.

Copper ore

Copper deposits are very diverse. In recent years, poor disseminated ores of the so-called porphyry type, which often occur in volcanic vents, have become very important. They were formed from hot solutions from deep magma chambers. The reserves of such ores are enormous, especially in South and North America.

Reservoir deposits are also of great importance. copper ore formed during volcanic eruptions at the bottom of the seas. This is the so-called pyrite type, in which copper pyrite - chalcopyrite- found in conjunction with iron pyrite - pyrite... These deposits for a long time served as the main source of ores in the Urals. Finally, the role of the so-called cuprous sandstones containing copper minerals. This type includes deposits in Chita region, and abroad the largest deposits Katanga in Africa.

Lead and zinc

Deposits have their own characteristics lead and zinc, these inextricably linked metals. The main mineral of lead is the luster of lead, or galena, a silvery-white mineral in cubic crystals.

Lead ore

Lead concentrates extract silver, bismuth, antimony... The latter form in the lead luster only a slight impurity, however, with a huge scale of smelting lead ore they constitute a very important addition to the extraction of these valuable elements from their own minerals. The main mineral of zinc is sphalerite(zinc blende). It is called a trick because it has a diamond luster rather than a metallic sheen like ore. Its color is different: from brown to black and cream. These two minerals, galena and sphalerite, have been said to constantly occur together.

Zinc concentrates

From zinc concentrates mine germanium, indium, cadmium and gallium... They form a very insignificant impurity in zinc blendes, where they replace zinc atoms in the crystal lattice, taking their place. And, despite the negligible content, it is the extraction of these small impurities from zinc blendes that is the main source of their production. They are of great value! For example, cadmium is used in the production of nuclear reactors, batteries, and low-melting alloys. Gallium, due to its low melting point (melting point only 30 degrees Celsius), is used as a substitute for mercury in thermometers. Cadmium with tin and bismuth gives Wood's alloy with a melting point of 70 degrees. Indium, added to silver, gives the latter a great shine, and in an alloy with copper protects the hulls of ships from corrosion in seawater. Germanium is used in the manufacture of semiconductors.

Sulphide ore

Often together with lead and zinc in ores are found silver, bismuth, arsenic, copper, therefore, lead-zinc deposits are called polymetallic. These deposits are formed from hot aqueous solutions and are especially often found in the form of deposits and veins among limestone which are replaced sulfide ore.

Tin and tungsten

Tin and tungsten belong to the rarer metals and represent special group(in practice they are now referred to the group of "colored"). The use of non-ferrous metals is very wide: in mechanical engineering, other fields of technology, in military affairs.

Imagine for a moment that the resources of such a metal as tin were depleted, the whole life would immediately rise: after all, tin alloys go to bearings necessary in any mechanism, without tin alloys it would be impossible to produce cars, electric locomotives, machine tools, the production of canned food (tin - metal cans). It would seem that such an inconspicuous metal like tin is an extremely necessary link in all technology.

Rare metal minerals

These metals are found in the form of oxygen compounds: tin - in the oxide, casiteite, or pewter stone, tungsten - in tungstic acid salts: tungsten and scheelite. Minerals these elements are often found in quartz veins among or near granites. Shiny black or brown wolframite crystals stand out sharply against the white quartz background. Sometimes they are found in other types of deposits: scheelitis at the contacts of granites with limestones in skarns, cassiterite- in sulphide veins. Oxygen compounds form many so-called rare metals: lithium, rubidium, cesium, beryllium, neobium, tantalum - they are often found in pegmatite veins. The ancient Precambrian pegmatites ( Africa, Brazil, Canada).

Light metals are now gaining in importance - aluminum and his even lighter brothers - magnesium and beryllium... These metals are rivals of the all-powerful iron, designed to replace it in many areas. These metals and their alloys are widely used in technology, especially in aircraft construction, rocketry, in the production of drill pipes - wherever light metal is needed.

Raw material for aluminum - bauxite

Aluminum, as you know, is very widespread in the earth's crust, and in the future it will be possible to obtain it from any aluminosilicate rocks rich in this element. In the meantime, traditional raw material for aluminum are bauxite... They consist of aqueous alumina compounds formed both by sedimentary deposition in sea basins and by weathering of aluminosilicate rocks. V Lately a method for producing aluminum from ancient crystalline shale formed during the metamorphism of clay deposits, as well as from alkaline igneous rocks... Thus, the problem of sources of aluminum production will never arise before a person: this metal is abundantly enough for all subsequent generations. It is only a matter of the technology of its extraction and electricity for the creation of powerful energy-intensive industries.

A different matter beryllium... It is a relatively rare metal. It is part of beryl and other minerals that are found in high-temperature deposits, in pegmatites, as well as in veins formed from hot aqueous solutions. This valuable metal is used in special alloys for making X-ray tubes.

The complex use of minerals is increasing. For example, rare elements are extracted from coal, mainly extremely valuable germanium.

An element like selenium, is not often found in independent minerals, but is present in pyrite and others sulfides in the form of an insignificant impurity, taking the place of sulfur; it is used to create semiconductors, optical devices, in particular binoculars, telegraph equipment, and colorless glass.