General characteristics of minerals
First of all, rocks and minerals that are used in the economy of countries are called minerals.
According to their physical condition, they can be:
- solid - coal, salt, ore, marble, etc.;
- liquid - oil, mineral water;
- gaseous - combustible gas, helium, methane.
When their use is taken as a basis, then they distinguish:
- fuels - coal, oil, peat;
- ore - ores of rocks, including metal;
- non-metallic - gravel, clay, sand, etc.
A separate group is represented by precious and ornamental stones.
Minerals were formed in different ways and by origin they are igneous, sedimentary, metamorphic, the distribution of which in the bowels of the earth obeys certain patterns.
Folded regions are usually characterized by igneous, i.e. ore minerals. This circumstance is due to the fact that they are formed from magma and hot gases released from it. aqueous solutions.
Magma rises from the bowels of the earth through cracks in the earth's crust and freezes in them at various depths.
Also, ore minerals can also be formed from erupted magma-lava, which cools relatively quickly. Magma is introduced, as a rule, during the period of active tectonic movements, therefore, ore minerals are associated with the folded regions of the planet.
Ores can also be formed on platform plains, but in this case they are confined to the lower tier of the platform. On platforms, ore minerals are associated with shields, i.e. with platform foundation outlets to the surface or in those places where the sedimentary cover does not differ in thickness, and the foundation comes close to the surface.
An example of such a field is the Kursk magnetic anomaly in Russia and the Krivoy Rog basin in Ukraine.
Remark 1
In general, an ore is a mineral aggregate from which metal or metal compounds can be extracted by technological means.
Metal ores are associated with areas of active mountain building, but the presence of mountains does not mean the presence of rich deposits. The third part of Europe, for example, is occupied by mountains, but there are very few large ore deposits.
Based on the field of application, ore minerals are divided into groups - ferrous metal ores, non-ferrous metal ores, precious metal ores and radioactive metals.
Such an ore mineral as iron ore is the basis for the production of ferrous metals - cast iron, steel, rolled products. The largest iron ore reserves are concentrated in the USA, India, China, Brazil, and Canada.
There are separate large deposits in Kazakhstan, France, Sweden, Ukraine, Venezuela, Peru, Chile, Australia, Liberia, Malaysia, North African countries.
In Russia, there are large reserves of iron ore, in addition to KMA, in the Urals, Kola Peninsula, in Karelia, In Siberia.
Ferrous metal ores
Among ferrous metal ores, iron ores are the most demanded and used in industry.
Minerals such as hematite, magnetite, limonite, siderite, chamosite and thuringite are the main iron-bearing rocks.
The extraction of iron ore in the world exceeds 1 billion tons. China is the largest iron ore producer with 250 million tons, while Russia produces 78 million tons. The United States and India produce 60 million tons each, Ukraine - 45 million tons.
Iron ore is mined in the United States in the Lake Superior region and in the state of Michigan.
In Russia, the largest iron ore basin is the KMA, whose deposits are estimated at 200-210 billion tons, or 50% of the planet's reserves. The field covers the Kursk, Belgorod, Oryol regions.
For the production of alloyed steel and cast iron, manganese is used as an alloying additive to give them strength and hardness.
World industrial reserves of manganese ores are concentrated in Ukraine - 42.2%. There are manganese ores in Kazakhstan, South Africa, Gabon, Australia, China, and Russia.
A large amount of manganese is also produced in Brazil and India.
In order for steel not to rust, to be heat-resistant and acid-resistant, chromium is needed, one of the main components of ferrous metal ores.
Specialists suggest that out of the world reserves of this ore, 15.3 billion tons of high-grade chromite ore falls on South Africa - 79%. In small quantities, chromium is found in Kazakhstan, India, Turkey, a fairly large deposit of this ore is located in Armenia. A small field is being developed in Russia in the Urals.
Remark 2
The rarest of the ferrous metals is vanadium. It is used for the production of grade iron and grade steel. Vanadium is very important for the aerospace industry because its addition provides high performance titanium alloys.
In the production of sulfuric acid, vanadium is used as a catalyst. It does not exist in its pure form, and vanadium is found in the composition of titanomagnetite ores, sometimes found in phosphorites, uranium-bearing sandstones and siltstones. True, its concentration is not more than 2%.
Sometimes even significant amounts of vanadium can be found in bauxites, brown coals, bituminous shales and sands. When extracting the main components from mineral raw materials, vanadium is obtained as a by-product.
According to the recorded reserves of this ore, the leaders are South Africa, Australia and Russia, and its main producers are South Africa, the USA, Russia, and Finland.
Ores of non-ferrous metals
Non-ferrous metals are represented by two groups:
- light, these include aluminum, magnesium, titanium;
- heavy ones are copper, zinc, lead, nickel, cobalt.
Of all the non-ferrous metals, aluminum is the most common in the earth's crust.
Among his physical properties such as low density, high thermal conductivity, ductility, electrical conductivity, corrosion resistance. This metal lends itself well to forging, stamping, rolling, drawing. It can be easily welded.
The feedstock for metallic aluminum is alumina, which is obtained by processing bauxite and nepheline ores.
There are bauxite reserves in Guinea, Brazil, Australia, and Russia ranks 9th in terms of them.
Russian bauxite reserves are concentrated in the Belgorod and Sverdlovsk regions, as well as in the Komi Republic. Russian bauxites are of low quality. Nepheline ores occur on the Kola Peninsula. In terms of alumina production, Russia ranks 6th in the world. All alumina is produced from domestic raw materials.
Titanium was discovered in 1791. Its distinctive characteristics are its high strength and corrosion resistance. For industry, the main type of titanium ores are coastal-marine placers. Such large placers are known in Russia, Australia, India, Brazil, New Zealand, Malaysia, and Sri Lanka.
Alluvial deposits of titanium are complex and contain zirconium.
Light non-ferrous metals include magnesium, which has been used in industry relatively recently. During the war years, most of it went to the production of incendiary shells, bombs, and flares.
Raw materials for the production of magnesium are confined to many regions of the planet. Magnesium is found in dolomite, carnallite, bischofite, cainite and other rocks that are widely distributed in nature.
The US accounts for about 41% of the world's production of magnesium metal and 12% of its compounds.
In addition to the United States, Turkey and North Korea are major producers of metallic magnesium. Magnesium compounds are produced by Russia, China, North Korea, Austria, Greece, Turkey.
Among heavy non-ferrous metals, copper stands out, which is a plastic element of a golden-pink hue, covered with an oxygen film in the open air.
A distinctive feature of copper is its high antibacterial properties. In alloys with nickel, tin, gold, zinc, it is used in industry.
After Chile and the USA, Russia ranks third in the world in terms of copper reserves.
In addition to native copper, the raw materials for its production are chalcopyrite and bornite. Copper deposits are distributed in the USA - the Rocky Mountains, in the Canadian Shield and the provinces of Quebec, Ontario in Canada, in Chile and Peru, in the copper belt of Zambia, the Democratic Republic of the Congo, in Russia, Kazakhstan, Uzbekistan, Armenia.
The main and major producers of this metal are Chile and the USA, as well as Canada, Indonesia, Peru, Australia, Poland, Zambia, and Russia.
Zinc was first obtained from calamine and is essentially zinc carbonate ZnCO2. Today, zinc is obtained from sulfide ores, the most important of which is zinc blende and marmatite.
Zinc ore is mined in Canada, the USA, Russia, Australia, Mexico, central Africa, Kazakhstan, Japan and other countries.
Major producers of zinc ore - Japan and the United States, they are also its major importers.
Known since antiquity, nickel, when added to steel, increases its viscosity, elasticity, and anticorrosion properties.
For the first time, metallic cobalt was obtained in 1735. Today it is used for the production of superhard alloys.
The raw material for lead is its main ore mineral galena. Lead ores are mined in many countries, and its leading producers are Australia, China, Peru, Canada.
Lead is mined in Kazakhstan, Russia, Mexico, Sweden, South Africa, and Morocco. There are large deposits of lead in Uzbekistan, Tajikistan, and Azerbaijan.
In Russia, lead deposits are concentrated in Altai, Transbaikalia, Yakutia, Primorye, and the North Caucasus.
Sedimentary rocks (SGR) are formed during the mechanical and chemical destruction of igneous rocks under the action of water, air and organic matter.
Sedimentary rocks are rocks that exist under thermodynamic conditions characteristic of the surface part of the earth's crust and are formed as a result of the redeposition of weathering products and the destruction of various rocks, chemical and mechanical sedimentation from water, the vital activity of organisms, or all three processes simultaneously.
Under the influence of wind, sun, water and due to temperature differences, igneous rocks are destroyed. Loose fragments of igneous rocks form loose deposits and from them layers of sedimentary rocks of clastic origin are formed. Over time, these rocks are compacted and relatively hard dense sedimentary rocks are formed.
More than three-quarters of the area of the continents is covered by the HGP, so they are most often dealt with in geological work. In addition, the vast majority of mineral deposits are genetically or spatially associated with the OGP. The remains of extinct organisms are well preserved in the OGP, which can be used to trace the history of the development of various parts of the Earth. Sedimentary rocks contain fossils (fossils). By studying them, you can find out what species inhabited the Earth millions of years ago. Fossils (lat. Fossilis - fossil) - fossil remains of organisms or traces of their vital activity belonging to previous geological eras.
Rice. Fossils: a) trilobites (marine arthropods found in the Cambrian, Ordovician, Silurian and Devonian periods) and b) fossilized plants.
The starting material for the formation of the GCP are minerals, formed due to the destruction of pre-existing minerals and rocks of igneous, metamorphic or sedimentary origin and transferred in the form of solid particles or dissolved matter. The science of "lithology" is engaged in the study of sedimentary rocks.
Various geological factors are involved in the formation of sedimentary rocks: the destruction and redeposition of the destruction products of pre-existing rocks, mechanical and chemical precipitation from water, and the vital activity of organisms. It happens that several factors take part in the formation of a particular breed at once. However, some rocks can be formed in different ways. So, limestones can be of chemical, biogenic or detrital origin.
Examples of sedimentary rocks: gravel, sand, pebbles, clay, limestone, salt, peat, oil shale, black and brown coal, sandstone, phosphorite, etc.
Rocks are not eternal and they change over time. The diagram shows the process of rock circulation.
Rice. The process of rock circulation.
On the basis of origin, sedimentary rocks are divided into three groups: clastic, chemical and organic.
Clastic rocks are formed in the processes of destruction, transfer and deposition of rock fragments. These are most often scree, pebbles, sands, loams, clays and loess. Clastic rocks are divided by size:
coarse clastic(> 2 mm); acute-angled fragments - gruss, crushed stone, cemented by clay shales, form breccias, and rounded fragments - gravel, pebbles - conglomerates);
- medium clastic(from 2 to 0.5 mm) - form sands;
Fine-grained, or dusty- form loesses;
- fine clastic or clayey (< 0,001 мм) – при уплотнении превращаются в глинистые сланцы.
Sedimentary rocks of chemical origin– salts and deposits formed from saturated aqueous solutions. They have a layered structure, consist of halide, sulfate and carbonate minerals. These include rock salt, gypsum, carnallite, flasks, marl, phosphorites, iron-manganese nodules, etc. (Table 2.4). They can be formed in a mixture with detrital and organic deposits.
Marl is formed by washing out calcium carbonate from limestones, contains clay particles, dense, light.
Iron-manganese nodules are formed from colloidal solutions and under the influence of microorganisms and create spherical deposits of iron ores. Phosphorites are formed in the form of cone-shaped concretions of irregular shape, at the confluence of which phosphorite slabs appear - deposits of gray and brownish phosphorite ores.
Rocks of organic origin are widely distributed in nature - these are the remains of animals and plants: corals, limestones, shell rocks, radiolarians, diatoms and various black organic silts, peat, black and brown coals, oil.
The sedimentary thickness of the earth's crust is formed under the influence of climate, glaciers, runoff, soil formation, vital activity of organisms, and it is characterized by zonality: zonal bottom silts in the World Ocean and continental deposits on land (glacial and water-glacial in the polar regions, peat in the taiga, salts in desert, etc.). Sedimentary strata accumulated over many millions of years. During this time, the zoning pattern changed many times due to changes in the position of the Earth's rotation axis and other astronomical reasons. For each specific geological epoch, it is possible to restore the system of zones with the differentiation of sedimentation processes corresponding to it. The structure of the modern sedimentary shell is the result of the overlap of many zonal systems at different times.
In most of the world, soil formation takes place on sedimentary rocks. In the northern part of Asia, Europe and America, vast areas are occupied by rocks deposited by glaciers of the Quaternary period (moraine) and the products of their erosion by melted glacial waters.
Moraine loams and sandy loams. These rocks are characterized by a heterogeneous composition: they are a combination of clay, sand and boulders of various sizes. Sandy loamy soils contain more SiO2 and less other oxides. The color is mostly red-brown, sometimes pale-yellow or light brown; the build is tight. A more favorable environment for plants is represented by moraine deposits containing boulders of calcareous rocks.
Cover clays and loams- boulderless, fine-earth rocks. Consist predominantly of particles smaller than 0.05 mm in diameter. The color is brownish-yellow, for the most part they have fine porosity. They contain more nutrients than the sands described above.
Loess-like loams and loesses are boulderless, fine-earth, carbonate, pale-yellow and yellow-yellow, finely porous rocks. Typical loess is characterized by the predominance of particles with a diameter of 0.05-0.01 mm. There are also varieties with a predominance of particles with a diameter of less than 0.01 mm. The content of calcium carbonate ranges from 10 to 50%. The upper layers of loess-like loams are often freed from calcium carbonate. The non-carbonate part is dominated by quartz, feldspars, and clay minerals.
Red-colored weathering bark. In countries with a tropical and subtropical climate, fine-earth deposits of the Tertiary age are widespread. They are distinguished by a reddish color, highly enriched in aluminum and iron, and depleted in other elements.
A typical example is laterite, a red-colored rock rich in iron and aluminum in hot and humid tropical regions, formed as a result of rock weathering.
Rice. Lateritic weathering crusts
Indigenous breeds. In large areas, pre-Quaternary marine and continental rocks, united under the name "bedrocks", come to the surface. These breeds are especially common in the Volga region, as well as in the foothills and mountainous countries. Among the bedrocks, carbonate and marl loams and clays, limestones, and sandy deposits are widespread. It should be noted that many sandy bedrocks are enriched in nutrients. In addition to quartz, these sands contain significant amounts of other minerals: micas, feldspars, some silicates, etc. As a parent rock, they differ sharply from ancient alluvial quartz sands. The composition of the bedrocks is very diverse and insufficiently studied.
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Minerals of Russia
Almost all types of minerals are available in sufficient quantities in our country.
Iron ores are confined to the crystalline basement of ancient platforms. The reserves of iron ore are large in the region of the Kursk magnetic anomaly, where the foundation of the platform is highly elevated and covered by a sedimentary cover of relatively small thickness. This allows you to mine ore in quarries. A variety of ores are confined to the Baltic Shield - iron, copper-nickel, apatite-nepheline (used for the production of aluminum and fertilizers) and many others. In the cover of the ancient platform on the East European Plain, there are various minerals of sedimentary origin. Coal is mined in the Pechora basin. Between the Volga and the Urals. in Bashkiria and Tataria, there are significant reserves of oil and gas. Large gas fields are being developed in the lower reaches of the Volga. In the north of the Caspian lowland, in the area of lakes Elton and Baskunchak, rock (cooking) salt is mined. Large reserves of potash and table salts are being developed in the Cis-Urals, in Polissya and in the Carpathian region. In many areas of the East European Plain - in the Central Russian, Volga, Volyn-Podolsk uplands, limestone, glass and construction sand, chalk, gypsum and other mineral resources are mined.
Within the Siberian platform, various deposits of ore minerals are confined to the crystalline basement. Large deposits of copper-nickel ores, cobalt and platinum are associated with the intrusion of basalts. In the area of their development grew The largest city Arctic - Norilsk. The granite intrusions of the Aldan shield are associated with reserves of gold and iron ore, mica, asbestos and a number of rare metals. In the central part of the platform, volcanic tubes of explosions formed along narrow basement faults. In Yakutia, a number of them carry out commercial diamond mining. In the sedimentary cover of the Siberian platform there are large deposits of coal (Yakutia). Its production increased sharply with the construction of the Baikal-Amur Railway. In the south of the platform, the Kansko-Achinsk brown coal deposit is located. In the depressions of the sedimentary cover there are promising oil and gas fields.
On the territory of the West Siberian Plate, minerals of only sedimentary origin have been discovered and are being developed. The foundation of the platform lies at a depth of more than 6 thousand meters and is not yet available for development. In the northern part of the West Siberian plate, the largest gas fields are being developed, and in the middle - oil fields. From here, gas and oil are supplied through pipelines to a number of regions of our country and the states of Western and Eastern Europe.
The most diverse in their origin and composition are mineral deposits in the mountains. Deposits of minerals are associated with ancient folded structures of the Baikal age, similar in composition to the fossils of the basement of ancient platforms. In the destroyed folds of the Baikal age there are deposits of gold (Lena mines). In Transbaikalia, there are significant reserves of iron ores, polymetals, cuprous sandstones, and asbestos.
The Caledonian folded structures combine mainly deposits of both metamorphic and sedimentary minerals.
The folded structures of the Hercynian age are also rich in various minerals. Iron and copper-nickel ores, platinum, asbestos, precious and semi-precious stones are mined in the Urals. Rich polymetallic ores are being developed in Altai. In the depressions among the folded structures of the Hercynian age there are gigantic reserves of coal.
In the spurs of the Kuznetsk Alatau there is an extensive Kuznetsk coal basin.
In areas of Mesozoic folding, there are deposits of gold in the Kolyma and in the spurs of the Chersky ridge, tin and polymetals in the Sikhote-Alin mountains.
Mineral deposits are rarer and not as rich in Cenozoic age mountain structures as in mountains with older folded structures. The processes of metamorphism and, consequently, mineralization proceeded weaker here. In addition, these mountains are less destroyed and their ancient inner layers often lie at a depth that is not yet available for use. Of all the mountains of the Cenozoic age, the Caucasus is the richest in minerals. As a result of intense fractures of the earth's crust and outpourings and intrusions of igneous rocks, mineralization processes proceeded more intensively. Polymetals and copper are mined in the Caucasus. tungsten, molybdenum and manganese ores.
Minerals of sedimentary rocks
On the surface of the Earth, as a result of the action of various exogenous factors, sediments are formed, which are subsequently compacted, undergo various physicochemical changes - diagenesis, and turn into sedimentary rocks. Sedimentary rocks cover about 75% of the surface of the continents with a thin cover. Many of them are minerals, others contain them.
There are three groups of sedimentary rocks:
Clastic rocks resulting from the mechanical destruction of any rocks and the accumulation of the resulting debris;
Clay rocks, which are the product of predominantly chemical destruction of rocks and the accumulation of clay minerals that have arisen in this case;
Chemical (chemogenic) and organogenic rocks formed as a result of chemical and biological processes.
When describing sedimentary rocks, as well as igneous rocks, one should pay attention to their mineral composition and structure. The first is a defining feature for chemical and organogenic rocks, as well as clayey ones in their microscopic study. Clastic rocks may contain fragments of any minerals and rocks.
The most important feature characterizing the structure of sedimentary rocks is their layered texture. The formation of layering is associated with the conditions of sediment accumulation. Any change in these conditions causes either a change in the composition of the deposited material or a stop in its supply. In the section, this leads to the appearance of layers separated by bedding surfaces and often differing in composition and structure. The layers are more or less flat bodies, the horizontal dimensions of which are many times greater than their thickness (thickness). The thickness of the layers can reach tens of meters or not exceed fractions of a centimeter. The study of layering provides a great deal of material for understanding the paleogeographic conditions under which the studied sedimentary sequence was formed. For example, in seas at a distance from the coast, under conditions of a relatively calm regime of water movement, parallel, primarily horizontal layering is formed, in coastal-marine conditions - diagonal, in sea and river flows - oblique, etc. An important textural feature of sedimentary rocks is also porosity, which characterizes the degree of their permeability for water, oil, gases, as well as stability under loads. Only relatively large pores are visible to the naked eye; smaller ones are easy to detect by checking the intensity of water absorption by the rock. For example, rocks that have a thin, invisible porosity stick to the tongue.
The structure of sedimentary rocks reflects their origin - clastic rocks consist of fragments of older rocks and minerals, i.e. have a clastic structure; clayey are composed of the smallest grains of predominantly clay minerals invisible to the naked eye - pelitic structure; chemobiogenic have either a crystalline structure (from clearly visible to cryptocrystalline), or amorphous, or organogenic, isolated in cases where the rock is an accumulation of skeletal parts of organisms or their fragments.
Most sedimentary rocks are the product of weathering and erosion of material from pre-existing rocks. A minor part of precipitation comes from organic material, volcanic ash, meteorites, mineralized waters. There are sediments of terrigenous (Table 1.), sediments of organic, volcanic, magmatic and extraterrestrial origin.
Table 1. Material composing sedimentary rocks
|
Primary Components |
Secondary Components |
||
|
clastic |
Released by chemical means |
Introduced |
Formed in the process of changing the breed |
|
Debris Quartzites Crystalline schists, phyllites, clayey (slate) schists Sandstones Coarse pyroclastic rocks (volcanic bombs, debris) Shards of glass, volcanic ash grains of minerals Chalcedony, flint, jasper Feldspar Muscovite magnetite, ilmenite Hornblende, pyroxene clay minerals |
Calcite, other carbonates Opal, chalcedony (quartz) Glauconite Manganese oxides carbonate material Anhydrite |
Opal, chalcedony Carbonates Iron hydroxides |
micaceous minerals Anhydrite Glauconite |
Minerals extracted from sedimentary rocks
Sedimentary rocks are of exceptional practical and theoretical importance. In this respect, no other rocks can compare with them.
Sedimentary rocks are the most important in practical terms: these are minerals, foundations for structures, and soils.
Mankind extracts more than 90% of minerals from sedimentary rocks. Most of them are taken only from sedimentary rocks: oil, gas, coal and other fossil fuels, aluminum, manganese and other ores, cement raw materials, salts, fluxes for metallurgy, sands, clays, fertilizers, etc.
Ores of ferrous and non-ferrous metals. The main metal of modern technology - iron is mined almost entirely (more than 90%) from sedilites, if we take into account the Precambrian ferruginous quartzites, which are currently metamorphic rocks, but retain their original sedimentary material composition. The main ores still remain young Meso-Cenozoic oolitic marine and continental deposits of alluvial, deltaic and coastal-marine types and weathering crust of tropical countries: Cuba, South America, Guinea and other countries of Equatorial Africa, the islands of Indian and Pacific Oceans, Australia. These ores are usually pure, readily available for open pit mining, often ready for the smelting process, and their reserves are colossal. They begin to compete with ferruginous quartzites, or jaspilites, of the Archean and Proterozoic, gigantic, the reserves of which are available on all continents, but they require enrichment. They are also developed in an open way, for example, in the Mikhailovsky and Lebedinsky quarries of the KMA, in Ukraine, in South Australia and other countries. In addition to these two main types, siderite ores of the Proterozoic (Riphean) Bakala (Bashkiria) are important. Other types are lacustrine-swampy (the iron ore plants of Petrozavodsk worked on them under Peter 1), volcanogenic-sedimentary (limonite cascades, etc.), siderite concretions of paralytic coal-bearing strata are secondary.
Manganese ores are 100% mined from sedimentary rocks. The main types of their deposits are shallow marine, confined to sponolites, sands, and clays. These are the giant deposits of Nikopol (Ukraine), Chiatura (Western Georgia), the eastern slope of the Urals (Polunochnoe, Marsyaty, etc.), as well as Laba (Northern Caucasus) and Mangyshlak. The most striking thing is that almost all of them are confined to a narrow time interval - the Oligocene. The second type is volcanic-sedimentary ores of the Paleozoic, mainly Devonian: in the Urals in the Magnitogorsk eugeosynclinal trough, often in jaspers; in Kazakhstan - in the depressions of the Atasu region, etc. Iron-manganese nodules of the oceans - minor ores for manganese. This metal can only be mined along with cobalt, nickel, copper.
Chrome ores, on the contrary, are mined mainly from igneous rocks, and sedimentary rocks account for only 7%.
All other components of ferrous metallurgy - fluxes - lowering the melting point (limestones), coke (coking coals), foundry sands - are mined entirely from sedimentary rocks.
Ores of non-ferrous and light metals are 100-50% mined from sedimentary rocks. Aluminum is completely smelted from bauxites, as is magnesium ores from magnesites of sedimentary genesis. The main type of bauxite deposits are modern or Meso-Cenozoic lateritic weathering crusts that develop in the tropical humid belt of the Earth. Other types are redeposited lateritic weathering crusts of near (colluvium, alluvium, karst strips) or somewhat more distant (coastal lagoon and other quiet zone) weathering. The largest such deposits are the Lower Carboniferous Tikhvin, Middle Devonian Krasnaya Shapochka, Cheremukhovskoye and other deposits that make up the North Ural bauxite region (SUBR), North American (Apkansas and others), Hungarian and others.
Magnesium is extracted mainly from magnesites and partly from dolomites of sedimentary genesis. The largest in Russia and the world are the Riphean Satka deposits in Bashkiria of a metasomatic, obviously catagenetic, genesis after primary dolomites. The thickness of the magnesite bodies reaches many tens of meters, and the thickness of the thickness is 400 m.
Titanium ores are 80% sedimentary, placer (rutile, ilmenite, titanomagnetites, etc.), consisting of residual minerals mobilized from igneous rocks.
Copper ores are 72% sedimentary - cuprous sandstones, clays, shales, limestones, volcanic-sedimentary rocks. For the most part, they are associated with red-colored arid formations of the Devonian, Permian, and other ages. Nickel ores are 76% sedimentary, mainly weathering crusts of ultrabasic rocks, lead-zinc ore is 50% volcanic-sedimentary, hydrothermal-sedimentary, and tin - cassiterite placers - 50% sedimentary.
Ores of "small" and rare elements are l00-75% sedimentary: 100% zircon-hafnium (placers of zircons, rutiles, etc.), 80% cobalt, 80% rare earth (monazite and other placers) and 75 % tantalum-niobium, also largely placer.
Sedimentary minerals most characteristic of platforms, as there is a platform cover. Mostly these are non-metallic minerals and combustibles, the leading role among which is played by coal and oil shale. They were formed from the remains of plants and animals accumulated in the coastal parts of the shallow seas and in the lacustrine-marsh conditions of the dry land. These plentiful organic remains could accumulate only in sufficiently moist and warm conditions favorable for luxuriant development. In hot dry conditions in shallow seas and coastal lagoons, salts accumulated, which were used as raw materials in.
Mining
There are several ways mining. Firstly, it is an open method in which rocks are mined in quarries. It is economically more profitable, as it contributes to obtaining a cheaper product. However, an abandoned quarry can lead to the formation of a wide network. The mine method of coal mining is expensive, therefore it is more expensive. The cheapest way to extract oil is by flowing, when oil rises through the well under oil gases. The pumping method of extraction is also common. There are also special ways of extracting minerals. They are called geotechnical. With their help, ore is mined from the bowels of the Earth. This is done by pumping hot water, solutions into the formations containing the necessary mineral. Other wells pump out the resulting solution and separate the valuable component.
The need for minerals is constantly growing, production is increasing, but minerals are exhaustible natural resources, so it is necessary to use them more economically and fully.
There are several ways to do this:
- reduction of losses of minerals during their extraction;
- more complete extraction of all useful components from the rock;
- integrated use of minerals;
- search for new, more promising deposits.
Thus, the main direction of the use of minerals in the coming years should not be an increase in the volume of their extraction, but a more rational use.
At contemporary search minerals, it is necessary to use not only the latest technology and sensitive instruments, but also a scientific forecast for the search for deposits, which helps to purposefully, on a scientific basis, conduct exploration of the subsoil. Thanks to such methods, diamond deposits in Yakutia were first scientifically predicted and then discovered. A scientific forecast is based on knowledge of the connections and conditions for the formation of minerals.
Brief description of the main minerals
The hardest of all minerals. Its composition is pure carbon. Occurs in placers and as inclusions in rocks. Diamonds are colorless, but there are also dyed in different colors. A cut diamond is called a diamond. Its weight is usually measured in carats (1 carat = 0.2 g). The largest diamond was found in the South: it weighed over 3,000 carats. Most diamonds are mined in Africa (98% of the production in the capitalist world). In Russia, large diamond deposits are located in Yakutia. Clear crystals are used to make gemstones. Until 1430, diamonds were considered common gemstones. The trendsetter for them was the Frenchwoman Agnes Sorel. Opaque diamonds, due to their hardness, are used in industry for cutting and engraving, as well as for grinding glass and stone.
Soft malleable yellow metal, heavy, does not oxidize in air. In nature, it is found mainly in its pure form (nuggets). The largest nugget, weighing 69.7 kg, was found in Australia.
Gold is also found in the form of placers - this is the result of the erosion of the deposit, when grains of gold are released and carried away, forming placers. Gold is used in the manufacture of precision instruments and various ornaments. In Russia, gold lies on and in. Abroad - in Canada, . Since gold is found in nature in small quantities and its extraction is associated with high costs, it is considered a precious metal.
Platinum(from Spanish plata - silver) - a precious metal from white to gray-steel color. Differs in infusibility, resistance to chemical influences and electrical conductivity. It is mined mainly in placers. It is used for the manufacture of chemical glassware, in electrical engineering, jewelry and dentistry. In Russia, platinum is mined in the Urals and Eastern Siberia. Abroad - in South Africa.
Gems(gems) - mineral bodies that have the beauty of color, brilliance, hardness, transparency. They are divided into two groups: stones for cutting and ornamental. The first group includes diamond, ruby, sapphire, emerald, amethyst, aquamarine. To the second group - malachite, jasper, rock crystal. All gemstones, as a rule, are of igneous origin. However, pearls, amber, coral are minerals of organic origin. Precious stones are used in jewelry and for technical purposes.
tuffs- rocks of various origins. Calcareous tuff is a porous rock formed as a result of precipitation of calcium carbonate from springs. This tuff is used to produce cement and lime. Volcanic tuff - cemented. Tuffs are used as a building material. Has different colors.
micas- rocks that have the ability to split into the thinnest layers with a smooth surface; found as impurities in sedimentary rocks. Various micas are used as a good electrical insulator, for the manufacture of windows in metallurgical furnaces, in the electrical and radio industries. In Russia, micas are mined in Eastern Siberia, c. Industrial development of mica deposits is carried out in Ukraine, in the USA, .
Marble- a crystalline rock formed as a result of limestone metamorphism. It comes in various colors. Marble is used as a building material for wall cladding, in architecture and sculpture. In Russia, there are many of its deposits in the Urals and the Caucasus. Abroad, marble quarried in is the most famous.
Asbestos(Greek inextinguishable) - a group of fibrous fireproof rocks, splitting into soft fibers of greenish-yellow or almost white color. It occurs in the form of veins (a vein is a mineral body that fills a crack, usually has a plate-like shape, going vertically to great depths. The length of the veins reaches two or more kilometers), among igneous and sedimentary rocks. It is used for the manufacture of special fabrics (fire insulation), tarpaulins, fire-resistant roofing materials, as well as thermal insulation materials. In Russia, asbestos is mined in the Urals, in, abroad - in other countries.
Asphalt(resin) - a fragile resinous rock of brown or black color, which is a mixture of hydrocarbons. Asphalt melts easily, burns with a smoky flame, is a product of the transformation of certain types of oil, from which some of the substances have evaporated. Asphalt often penetrates sandstones, limestones, marl. It is used as a building material for road surfacing, in electrical engineering and the rubber industry, for the preparation of varnishes and mixtures for waterproofing. The main asphalt deposits in Russia are the Ukhta region, abroad - in, in France,.
Apatity- minerals rich in phosphoric salts, green, gray and other colors; found among various igneous rocks, sometimes forming large accumulations. Apatites are mainly used for the production of phosphate fertilizers, they are also used in the ceramics industry. In Russia, the largest deposits of apatite are located in, on. Abroad they are mined in the Republic of South Africa.
Phosphorites- sedimentary rocks rich in phosphorus compounds, which form grains in the rock or hold together various minerals into a dense rock. Phosphorites are dark grey. They are used, like apatites, to obtain phosphate fertilizers. In Russia, phosphorite deposits are common in the Moscow and Kirov regions. Abroad, they are mined in the USA (Peninsula Florida) and.
aluminum ores- minerals and rocks used to produce aluminium. The main aluminum ores are bauxites, nephelines and alunites.
bauxites(the name comes from the Bo area in the south of France) - sedimentary rocks of red or Brown. 1/3 of their world reserves lie in the north, and the country is one of the leading states in their production. In Russia, bauxites are mined in. The main component of bauxite is aluminum oxide.
Alunites(the name comes from the word alun - alum (fr.) - minerals, which include aluminum, potassium and other inclusions. Alunite ore can be a raw material for obtaining not only aluminum, but also potash fertilizers and sulfuric acid. There are deposits of alunites in the USA , China, Ukraine, and other countries.
Nephelines(the name comes from the Greek "nephele", which means cloud) - minerals of complex composition, gray or green, containing a significant amount of aluminum. They are part of the igneous rocks. In Russia, nephelines are mined in and in Eastern Siberia. The aluminum obtained from these ores is a soft metal, gives strong alloys, is widely used, as well as in the manufacture of household goods.
Iron ores- natural mineral accumulations containing iron. They are diverse in terms of mineralogical composition, the amount of iron in them, and various impurities. Impurities can be valuable (chromium manganese, cobalt, nickel) and harmful (sulfur, phosphorus, arsenic). The main ones are brown iron ore, red iron ore, magnetic iron ore.
brown iron ore, or limonite, is a mixture of several minerals containing iron with an admixture of clay substances. It has a brown, yellow-brown or black color. It occurs most often in sedimentary rocks. If the ores of brown iron ore - one of the most common iron ores - have an iron content of at least 30%, then they are considered industrial. The main deposits are in Russia (Ural, Lipetsk), in Ukraine (), France (Lorraine), on.
Hematite, or hematite, is a red-brown to black mineral containing up to 65% iron.
It occurs in various rocks in the form of crystals and thin plates. Sometimes it forms clusters in the form of hard or earthy masses of bright red color. The main deposits of red iron ore are in Russia (KMA), Ukraine (Krivoy Rog), USA, Brazil, Kazakhstan, Canada, Sweden.
Magnetic iron ore, or magnetite, is a black mineral containing 50-60% iron. It is high quality iron ore. Composed of iron and oxygen, highly magnetic. It occurs in the form of crystals, inclusions and solid masses. The main deposits are in Russia (Urals, KMA, Siberia), Ukraine (Krivoy Rog), Sweden and the USA.
manganese ores- mineral compounds containing manganese, the main property of which is to impart malleability and hardness to steel and cast iron. Modern metallurgy is unthinkable without manganese: a special alloy is smelted - ferromanganese, containing up to 80% manganese, which is used for smelting high-quality steel. In addition, manganese is necessary for the growth and development of animals, it is a microfertilizer. The main ore deposits are located in Ukraine (Nikolskoye), India, Brazil and the Republic of South Africa.
Tin ores- Numerous minerals containing tin. Tin ores with a tin content of 1-2% or more are being developed. These ores require enrichment - an increase in the valuable component and the separation of waste rock, therefore, ores with a tin content increased to 55% are used for smelting. Tin does not oxidize, which caused it wide application in the canning industry. In Russia, tin ores occur in Eastern Siberia and on, and abroad they are mined in Indonesia, on the peninsula.
Nickel ores- mineral compounds containing nickel. It does not oxidize in air. The addition of nickel to steels greatly increases their elasticity. Pure nickel is used in mechanical engineering. In Russia, it is mined on the Kola Peninsula, in the Urals, in Eastern Siberia; abroad - in Canada, on, in Brazil.
Uranium-radium ores- mineral accumulations containing uranium. Radium is a product of the radioactive decay of uranium. The content of radium in uranium ores is negligible - up to 300 mg per 1 ton of ore. have great importance, since nuclear fission of each gram of uranium can give 2 million times more energy than burning 1 gram of fuel, so they are used as fuel in nuclear power plants to produce cheap electricity. Uranium-radium ores are mined in Russia, the USA, China, Canada, Congo, and other countries of the world.
From school, I knew in general terms how sedimentary rocks were formed. Over the years since graduation, I have been able to learn more about this process. I will share my knowledge with you.
Formation of deposits of sedimentary minerals
This type of fossil is, in fact, a huge layer of compressed sediment accumulated over time. This sedimentary material is the basis. It is formed in different ways, depending on the conditions (under water, on land or in the bowels of the planet). On land and in water bodies, these are the waste products of plants and, in part, animals. Some breeds lend themselves to destructive power water streams, gravity, glaciers, temperature changes, breaking up into fragments of different sizes and, thereby, becoming a material. Then on land, this is all subjected to chemical decomposition through:
- natural waters;
- carbon dioxide;
- free oxygen;
- organic acids.
Oxygen - oxidizes, carbon dioxide and acids - decompose.
In the water column, gaseous and dissolved substances through chemical reactions and the vital activity of organisms are able to pass into the solid phase, forming sedimentary material.
Volcanic activity brings material from the bowels.
Examples of sedimentary rocks and their deposits
The place where sedimentary material accumulated massively is called a deposit.
Among the minerals that are extracted from sedimentary rocks are: salts, oil, sands, gas, clays, cement raw materials, coal, fluxes for metallurgy, aluminum, magnesium, manganese, titanium, copper, nickel, cobalt, tin ores, partially chrome, lead-zinc.
Deposits of manganese ores: Nikopol (Ukraine), Mangyshlak, Polunochnoe and Marsyaty (slopes of the Urals).
The most impressive accumulations of magnesium ores in the world are the Satka deposits (Russia, Bashkiria).
Coal basins: Tunguska and Kuzbass (Russia), Illinois and Appalachian (USA), Ruhr (Germany).
Large-scale salt deposits: Dead Sea, Soledar (Ukraine), Belzhanskoye (Russia), Kara-Bogaz-Gol Bay (Turkmenistan).
Home > Diploma1.2.4. Minerals of sedimentary origin.
The largest number of types of mineral raw materials within the Arkhangelsk region is associated with sedimentary rocks, since they cover most of it.
Oil and combustible gas.
They occur on the territory of the Nenets Autonomous Okrug and are confined to many kilometers of sedimentary rocks of the Pechora Plate. Among the useful components are oil itself, combustible gas both in free form and dissolved in oil, paraffin and sulfur. The first geophysical studies for oil and gas in the district began in 1956. In 1966, the first gas field in the Nenets tundra was discovered, which was named Shapkinskoye. As a result of extensive exploration work on the territory of the Nenets Autonomous Okrug, a real resource base has been created. Already today, geology has become the leading branch of the national economy, which employs a third of the working population of the region. 75 fields were discovered: 64 oil, 6 oil and gas condensate, 3 gas condensate, 1 gas, 1 gas and oil. The initial total resources are 2407 million tons of oil, 1170 billion cubic meters of free gas, 44 million tons of gas condensate, 133 billion cubic meters of dissolved gas. In terms of the richness of the subsoil with oil and gas resources, the Nenets Okrug ranks third after the Khanty-Mansiysk and Yamal-Nenets districts. In terms of raw materials, the share of the Nenets Okrug accounts for about 53% of the oil and gas of the Timano-Pechora province. Despite the fact that 75 hydrocarbon deposits have been discovered in the Okrug, 4 deposits are currently in operation: Peschanoozerskoye (Kolguev Island), Kharyaginskoye, Ardalinskoye and Vasilkovskoye. 14 deposits have been prepared for industrial development, the rest are in various stages of prospecting and exploration. Oil on the territory of the district is not processed and is transported in its raw form outside of it. The Prirazlomnoye oil field and the Shtokman gas field were discovered on the shelf of the Barents Sea. According to the results of prospecting and exploration, the potential of the Barents Sea shelf is comparable in terms of resources to the West Siberian oil and gas province. In principle, the shelf forms a single large super-province with the Timan-Pechora province, which is a unique resource base for hydrocarbons. The oil companies of the USA, Norway, Finland, and Great Britain are showing great interest in the hydrocarbon resources of the Okrug. Since 1994, the Polar Lights JV, founded by Arkhangelskgeologiya and the American company Conoco, has been producing oil at the Ardalinskoye field.
Coal
Several non-industrial coal deposits have been discovered on the southwestern slope of Pai-Khoi in the Karataikha river basin: Talatinskoye, Vas-Yaginskoye, Yangareyskoye, Kheyyaginskoye, Nyamdoyusskoye, Silovskoye. On the northeastern slope of Pai-Khoi and on the Volong River in the Northern Timan, coal manifestations have also been established. Their low-power interlayers have no industrial value because of the high ash content. In the most last years within the Nenets Autonomous Okrug, it was possible to trace the marginal part of the mine field with high-quality coals of the Vorgashorskaya mine, the largest in Vorkuta. Oil shale is widespread on the territory of the Nenets Okrug. Their reserves are estimated at about 5 billion tons.
bauxites
Bauxite consists mainly of hydrated aluminum oxide (Al 2 O 3 nH 2 O) and iron (III) oxide (Fe 2 O 3 mH 2 O), as well as silica SiO 2 and various impurities. In our region, bauxite deposits have been explored in the Plesek district. These are the Iksinskoye, Bulatovskoye, Plesetskoye and Denislavskoye deposits. They are among the largest bauxite deposits in Russia and the only ones in Europe. A distinctive feature of the North Onega bauxites is the presence in their composition, in addition to aluminum, of a number of valuable associated components. Bauxite deposits are located at shallow depths and are mined in an open pit. Bauxite is the main raw material for the industrial production of aluminum. In addition, North Onega bauxites are used for the production of high-quality abrasives and electrocorundum, as well as refractory materials.
Gypsum and anhydrite.
The reserves of gypsum and anhydrite are especially large in the Arkhangelsk region. Gypsum is a mineral whose chemical composition is calcium sulfate hydrated with two water molecules CaSO 4 2H 2 O Anhydrite is a mineral that is anhydrous calcium sulfate. The largest deposits of gypsum and anhydrite are concentrated in the valleys of the Northern Dvina, Pinega and Kuloy rivers. The largest deposits are: Zvozskoye (on the Northern Dvina), Mehrengskoye (on the Mekhrenga River in the Plesetsk region), Pinezhskoye and Siyskoye (in the Pinega river basin). Gypsum is widely used in the national economy. It is a valuable chemical raw material and is used in the production of sulfuric acid, in the pulp and paper industry as a filler for paper, in the construction industry for the production of alabaster and cement, in agriculture for soil gypsum, in metallurgy, in medicine, for modeling and casting work. , in the production of paints. Selenite (fibrous gypsum) is used in the stone-cutting industry as a facing and ornamental stone.
Carbonate rocks (limestone and dolomite).
According to the chemical composition, limestone is calcium carbonate CaCO 3, and dolomite is calcium-magnesium carbonate CaMg (CO 3) 2. They are raw materials for the production of cement, are used in the pulp and paper industry, in agriculture - for liming soils, for obtaining lime, as rubble and crushed stone. The largest deposits of carbonate rocks are: Orletskoe in the Kholmogorsk region, Obozerskoe, Shvakinskoe, Kyamskoe and Yemetskoe in the Plesetsk region. The reserves of carbonate raw materials in the Arkhangelsk region are quite large.
Clay brick.
They are used to make bricks and tiles. The most suitable deposits from among the explored ones are: in the area of Arkhangelsk - Uemskoye and Glinnikskoye, in the Onega district - Andskoye, in the Kholmogorsky district - Malotovrinskoye, Ukhostrovskoye and Khorobitskoye, in the Velsky district - Vazhskoye and Kochevskoye, in Krasnoborsky - Krasnoborskoye, in Verkhnetoemsky - Lebashskoye, in Mezensky - Mezenskoye, in Shenkursky - Pavlovsky, in Kargopolsky - Poluborsky, in Vinogradovsky - Semenovsky, in Ustyansky - Shangalsky, in Pinezhsky - Shotovsky, in the Nenets Autonomous Okrug - Naryan-Marskoye.
Expanded clay clays.
Some varieties of fusible clays and loams are suitable for the production of expanded clay, an artificial porous small-sized material used for heat and sound insulation, as a filler for concrete. The following deposits are known in the Arkhangelsk region: Kazarma (Kotlassky district), Kudemskoye (Primorsky district), Tesovka (Onega district), Berezniki (Vilegodsky district), Oktyabrskoye (Ustyansky district).
Clays are cement.
They are a valuable raw material used as one of the components in the production of cement. The deposits are located in the Plesetsk region (Timme and Sheleksa).
Building sands and gravel.
Sands, gravel and boulder material are essential for road construction and are used as aggregates for concrete and mortars. Deposits of various sizes are found throughout the region. The largest accumulations are the deposits of Normenga, Obloozero, Podyuga-Zvenyache, Nimenga, Malaya Rechka, Nyandoma-3, Nyandoma-5, etc. All of them are developed by an open pit (quarry).
Metal ore occurrences.
Metal manifestations are also known in sedimentary rocks. Strontium in the form of the mineral celestine (SrSO 4) is found near the village of Valtevo on the Pinega River. Manganese manifestations are known at Pai-Khoi.
The groundwater.
In terms of composition and use, groundwater can be divided into 3 large groups: fresh for domestic and drinking water supply, mineral medicinal and drinking water and brines - raw materials for chemical. processing to obtain food salt and various substances for technical use.
Fresh waters.
The reserves of 16 largest fresh water deposits have been explored, calculated and approved, without taking into account the numerous outlets of fresh water in wells, springs, wells used for local needs in villages and settlements. In terms of their composition, fresh waters are mainly of the hydrocarbonate type. Most deposits are associated with limestone and dolomite aquifers. Fresh water is used for household and drinking water supply in Kargopol, Nyandoma, Velsk, Naryan-Mar and other settlements. One of the largest in the European part of Russia is the Permilovskoye and Tundro-Lomovoe underground fresh water deposits. They are located respectively 100 and 50 km from Arkhangelsk. The waters in them are low-pressure, hydrocarbonate in composition with a mineralization of 0.3-0.7 g/l. Occurring at depths of several tens of meters, they are quite reliably protected from the surface and are replenished by atmospheric precipitation and groundwater from neighboring areas. Fresh water reserves in these deposits are quite large and can provide water supply to Arkhangelsk and Severodvinsk for many years.
Mineral underground waters.
They are quite diverse in their chemical composition. For many centuries, sodium chloride, hydrogen sulfide sources and silt muds of Solvychegodsk have been used. In recent years, the Solvychegodsk resort began to use bromine waters explored by geologists for treatment. Approximately in the 17th century, the population of the North of Russia used the waters of the Talets spring in the valley of the river for medicinal purposes. Verkhovki on the Onega Peninsula. Its waters are similar in composition to the Narzan waters of the North Caucasus. In recent years, the Kurtyaevskoye deposit of hydrocarbonate-calcium chloride sodium waters has been explored here. In the 80s of the XX century, various types of mineral healing waters were found and explored in the vicinity of Arkhangelsk. So, in the resort of Belomorye, 40 km from Arkhangelsk, bromine chloride calcium-sodium water is used for drinking and bathing. Based on this deposit, Belomorskaya mineral water is bottled. Several types of mineral waters for drinking and bathing have also been found in Severodvinsk. They are used in medical institutions in Arkhangelsk and Severodvinsk. Chloride bromine-boron water is used in the Sosnovka sanatorium near Velsk. In 1985, in the city of Naryan-Mar, mineral water was found in 3 wells - on the territory of a fish factory, near the airport and in the village of Fakel. In 1995, after the purchase and debugging of equipment, the production of Naryan-Marskaya-1 mineral water began. Water from the well is diluted into 3 parts fresh water, filtered and cooled to plus 4 degrees for better saturation carbon dioxide in the saturator. After that, the water is sent for bottling.
Pickles.
These are highly mineralized underground waters. Within the region, they were known and widely used for salt production as early as the 12th century. At most old deposits, they have long been depleted and are not currently mined. In recent years, a large salt deposit of more than 100 g/l has been explored in the Koryazhma region. The exploitation of this deposit will make it possible to obtain large quantities of edible salt and a number of other chemicals for technical needs. In the Arkhangelsk region, a deposit of iodine waters suitable for obtaining solid iodine has been studied. Geological research in the Arkhangelsk region is ongoing and the discovery of new mineral deposits can be expected. Mineral deposits that are found on the territory of the Arkhangelsk region are marked on the map, which is placed in Appendix 2 of this work.
1.2.5. Prospects for the use of minerals in the Arkhangelsk region in the national economy.
The bowels of the European North are rich in natural resources. Conducted geological exploration work shows that the Arkhangelsk region occupies not only the central geographical position in the European North, but also the most important in terms of the prospects for the development of the mineral and raw materials and fuel and energy complexes. Opportunities for the use of minerals are currently far from being fully exploited. So far, the capacity of bauxite mines is low. The development of the metallurgical complex has great prospects. because outside the region it is more profitable to export products, not ore. The industrial development of northern bauxites can ensure a sufficient increase in aluminum production and the creation of a reliable raw material base for other alumina refineries in our country. There is reason to talk about the possibility of forming such industrial regions as Timan-Kaninsky, Novozemelsko-Amderma, the Wind Belt region, etc. Amderma deposits of fluorites, Timan agates are already known here, there are good prerequisites for discovering deposits of copper and polymetals on Novaya Zemlya, nickel, and titanium , manganese, polymetals, amber, precious stones and other important minerals on Timan, Pai-Khoi, Wind Belt. Iron ore deposits have been discovered in the Konosha region. Exploration work has shown that the region is rich in such minerals, which must first of all be used for the internal needs of the region. These are non-metallic raw materials and groundwater. The building materials industry is not well developed in the region. There is an acute shortage of them. Our region has sufficient stocks of raw materials for the building materials industry. The basalts of the Myandukha Mountain can be used not only for the production of crushed stone, but also as a facing stone, for stone casting, for the production of mineral canvas, cardboard, and cotton wool. Gypsum can be used not only as a building material, but also as a molding, ornamental, and also in agriculture, paper industry. There are very numerous deposits of sand and gravel material, which is suitable for road construction. Thinking about the prospects for the development of the region, it should be taken into account that the mineral resource complex of the region will give an incomparably greater return if the issues of not only extraction, but also processing of natural raw materials are resolved.
1.3. Methods for studying minerals.
To determine (diagnose) minerals, there is a complex of various methods, ranging from the simplest, superficial, to detailed studies using special instruments. In practice, the simplest is the definition of minerals by their external form - the morphological features of crystals and their aggregates. But this is possible only in those rare cases when the form of the mineral is typical and it is represented by sufficiently large crystals or homogeneous monomineral aggregates. To determine a mineral, morphological features alone are not enough, it is necessary to apply more complex methods, for example, studying the complex of its physical properties. The simplest chemical reactions help to establish the presence or absence of individual chemical elements in a mineral.
1.3.1. Methods for studying physical properties.
To establish whether a given sample belongs to a particular species, they carefully study the external shape and physical properties of minerals in aggregate. characteristic features using a special mineral guide. The course of determining the mineral is as follows. First of all, the hardness of the mineral is established. To do this, the tested mineral is drawn on known minerals or on objects with known hardness. Then the luster of the mineral is determined, for this it is necessary to find a fresh split surface. The color of the mineral and the color of the line, the nature of the fracture are noted. A mineral is determined by a complex of physical properties. The complex of physical properties of the minerals of the Arkhangelsk region is given in the appendix of this work.
1.3.2. Methods for studying the chemical composition.
In the field, you can make a preliminary qualitative analysis. For chemical analysis, solutions are often taken, obtained after the treatment of ores and minerals with acids, and they are also acted upon with solutions of reagents. But in the field, distilled water, necessary for the preparation of solutions, is impossible to get. In addition, experience shows that chemical reactions can also be carried out between solid substances if they are ground (the grinding method is one of the dry methods of qualitative analysis). Back in the 19th century, Professor of Kazan University Flavitsky F.M. He proved very convincingly that all reactions that were previously carried out in solutions also succeed when they are carried out between solid substances. Flavitsky even invented a pocket chemistry lab that could be used to carry out chemical reactions. It used pure salts. But it is extremely difficult to isolate a salt of any metal in its pure form from an ore or mineral in order to carry out a reaction between solid substances. But what if you carry out the reaction directly with the mineral? Practice has confirmed that in most cases this can be done. But sometimes the reaction may not occur. How to be then? As mentioned above, to obtain solutions, ores and minerals are treated with acids. Is it possible to decompose them without acids? It turns out you can. As you know, ammonium salts decompose when heated. For example, ammonium sulfate decomposes into ammonia, sulfur oxide (VI) and water. Ammonium chloride decomposes into ammonia and hydrogen chloride. Due to this feature of ammonium salts, they are used to decompose minerals. When minerals are heated with ammonium sulfate, sulfates of those metals that were part of the ore are formed. After decomposition, the mass has a light gray color. It is impossible to overheat the mass too much, because. some sulfates decompose to oxides when heated strongly. When the mineral is decomposed by ammonium chloride, metal chlorides are formed. But it must be taken into account that some chlorides evaporate with strong heating. These are iron (III) chloride, aluminum chloride, titanium (IV) chloride, antimony (V) chloride and some others. Thus, one must be able to choose the right ammonium salt, which would be suitable for the decomposition of ores and minerals. Analytical reactions can be carried out on the surface of minerals. To do this, a piece of mineral is beaten off with a geological hammer and a reaction is carried out at the site of a fresh fracture. It is also possible to first carefully clean the chosen place on the mineral with a steel knife in order to remove the surface layer and carry out the reaction on the exposed surface. A little of the desired reagent is placed on a cleaned place or a fresh fracture and rubbed on the smallest possible area with a glass rod. It is important that the end of the glass rod is not rounded, but flat, but without sharp edges. If the reaction on the surface did not give the expected result, this does not mean that the element being determined is absent. Then carry out the reaction with the crushed mineral. A small portion of the mineral is placed in a mortar and rubbed with a pestle as thoroughly as possible. The powder is then transferred to a porcelain crucible, the required reagent is added, and the mixture is triturated carefully and very thoroughly. Sometimes the mass needs to be moistened with breathing. To do this, they breathe on the crucible and take it away from the mouth during inhalation so that powdered reagents do not enter the respiratory tract. Humidification is also useful by adding a drop of distilled water to the crucible. If the reaction with the crushed mineral does not give a positive result, the crushed sample is decomposed by heating with ammonium sulfate. If the decomposition does not end the first time, then add a new portion of ammonium sulfate and continue heating. Continue heating until the emission of white smoke - sulfur oxide (VI) ceases.
1.3.3. The results of the study of minerals.
In the course of the work, the physical properties and chemical composition of 13 minerals were studied. All of them are found on the territory of the Arkhangelsk region. Of these, 7 minerals form deposits suitable for industrial development, and 6 minerals form ore occurrences that are not suitable for industrial development. Of the physical properties of minerals, the following have been studied: hardness, brilliance, transparency, color of the mineral, color of the line, fracture, density, brittleness. Chemical composition tested by dry and wet methods. Of the 13 minerals, 1 was subjected to dry analysis only; 8 minerals - only wet analysis; 4 dry and wet. The analysis methods are included in the appendix. Table. Qualitative analysis of minerals and rocks of the Arkhangelsk region.
| Minerals | chemical formula | dry method analysis | wet analysis |
|
| 1 | Anhydrite | |||
| 2 | Antimonite | |||
| 3 | Bauxite | Al 2 O 3 H 2 O | ||
| 4 | Galena | |||
| 5 | Gypsum | CaSO 4 2H 2 O | ||
| 6 | Dolomite |
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