Page 7

Copper ore deposits. Copper is the most important non-ferrous metal. It is characterized by a low metal content in the ore (1-2%) and often occurs in combination with zinc, lead, gold, and silver. Large deposits of copper ore have been explored in the Urals, the North Caucasus, and Eastern Siberia.

In the Urals, the largest deposits - Degtyarskoye, Krasnouralskoye, Kirovogradskoye, Revdinskoye - are located in the Sverdlovsk region. The Karabashskoye field is located in the Chelyabinsk region, and the Raiskoye and Blavinskoye fields are in the Orenburg region.

In the Republic of Bashkortostan, the richest deposits are Sibay and Uchalinskoye. In the North Caucasus - Urupskoye and Khudesskoye in the Stavropol Territory.

There are deposits in Western Siberia and Altai. In Eastern Siberia, in the Krasnoyarsk Territory, the main reserves of copper-nickel ores are located, where the Norilsk, Talnakh, and Oktyabrskoe deposits are particularly prominent. The unique Udokan deposit is located in the Chita region. Reserves of copper-nickel ores are available in the North, in the Murmansk region.

Deposits of polymetallic ores. Polymetallic lead-zinc ores of Russia are concentrated in Western Siberia - the Salair group (Altai Territory), Eastern Siberia - the Nerchinsk group (in Transbaikalia), the Gorevskoye deposit in the Krasnoyarsk Territory, and in the Far East - the Tetyukhinsky group (Primorsky Territory).

Deposits of nickel and cobalt. The main deposits of nickel ores are located in the Murmansk region (Kaula), Orenburg (Buruktalskoye) and Chelyabinsk (Cheremshanskoye) regions, Krasnoyarsk Territory (Norilskoye, Talnakhskoye).

The bulk of cobalt produced in the country is carried out by processing complex ores.

Tin deposits. The main location area is the Far East. The largest deposits are in the areas of the Lesser Khingan and Sikhote-Alin ridges, Southern Primorye and the river basin. Yana.

Deposits of light metals. Of the light metals, aluminum and magnesium play an important role in industry. Aluminum plays a leading role in industrial production, its alloys are widely used in the aviation and space industries. Magnesium is widely used in pyrotechnics, photography, the aviation and nuclear industries, as well as in ferrous and non-ferrous metallurgy.

To obtain aluminum, three main types of feedstock are used - bauxite, nepheline and alunite.

Bauxite is a sedimentary rock that contains alumina, silicon and ferrous oxide. The alumina content in bauxite ranges from 40-70%. Bauxite deposits have been explored in the Urals (in the Sverdlovsk region - North-Uralskoye, in the Chelyabinsk region - South-Uralskoye), in the North-West (in the Leningrad region - Tikhvinskoye), in the North (in the Arkhangelsk region - North-Onega), as well as in Eastern Siberia (in the Krasnoyarsk Territory and the Republic of Buryatia).

Nephelines are found in many areas of the country. The largest deposit in Russia is located in the Murmansk region (Khibinskoye), in Western Siberia (Kemerovo region - Kiya-Shaltyrskoye field), in a number of areas of Eastern Siberia - in the Irkutsk region and the Republic of Buryatia.

Deposits of magnesium ore (magnet) are being developed in the Urals (Satka) and in the Eastern Sayan Mountains.

Deposits of precious metals and diamonds. The Russian Federation is one of the largest producers of precious metals and precious stones. The forecast reserves of gold resources are estimated at 150 thousand tons. Russia ranks fifth in the world in gold production, accounting for 6-7% of world production. The main gold deposits are found in bedrock in the form of quartz-gold veins and placers. They are located in the Urals, in Eastern Siberia (Krasnoyarsk Territory and Irkutsk Region), in the Far East (in the Republic of Sakha (Yakutia) and the Magadan Region), as well as in Western Siberia and the European North of the country.

The mineral resources of the Urals are represented by jewelry diamonds and other minerals, as well as various metals and non-metals.

The very first Urals that began to be mined, the history of their mining began about 4 thousand years ago.

Much later, approximately in the V-III centuries BC. e., began to mine iron ore. Gold began to be mined in the 1st millennium BC. Since the deposits reaching the surface, where the minerals of the Urals were located, quickly dried up, it was necessary to carry out deeper developments. But temporarily this type of human activity fell into decline, since in the first millennium BC. the entire Southern Urals are inhabited by nomads who were not involved in the mining and smelting of metals.

Only 1.5 thousand years later, people began to mine the minerals of the Urals again, and a new era of using these resources began.

Minerals of the southern Urals

Black metals

From the end of the 18th century to the present day, brown iron ores have been mined. At the beginning of the last century, iron ore deposits began to be developed at a rapid pace, and the Magnitogorsk Iron and Steel Works was built, but today the ore reserves here are practically exhausted. Not far from Magnitogorsk, a deposit of magnetite and titanomagnetite ores is being developed, which is called Maly Kuybas.

The mineral resources of the Urals are represented not only by iron ores, but also by others such as titanium, chromium, vanadium, and manganese.

Currently, deposits of iron-titanium-vanadium ores are being developed, the reserves of which are very large. They have a high iron content - up to 57%, titanium - up to 6.5%, vanadium - up to 0.4%.

Non-ferrous metals

In the Southern Urals there are many ores of various non-ferrous metals. A large number of deposits of sulfide copper, as well as deposits of sulfide ores, have already been developed. Since they are located at a shallow depth, they are being mined open-pit. Not far from the Arkaim nature reserve, a zinc deposit was discovered at the end of the last century and is now being developed. The main difference between pyrite ores is that they always have several components. If the main ones are zinc and copper, then along with them there is a fairly high amount of gold, lead, silver, as well as such rare metals as gallium, indium, scandium, mercury and others. Sulfur is also obtained from these ores.

Along with pyrite ores, there are significant deposits of porphyry copper ores, which contain a significant amount of molybdenum.

The Ufaley nickel-cobalt ore deposits are known far beyond the country's borders. Some of them have already been worked out, but a constant search for new deposits of these ores is being carried out. There are deposits of bauxite, from which aluminum is smelted.

Noble metals

The Southern Urals are the main supplier of gold to the state treasury. It was in the Urals that a nugget of this metal weighing about 36 kilograms was found. carried out from mines whose depth reaches 700 m. Gold and silver are also mined by processing pyrite ores.

Rare metals

This includes tungsten, tin, tantalum, beryllium and others. Mining of such a rare mineral as columbite is underway. It is from it that niobium is extracted; zirconium ores are also mined, along with which ceramic feldspathic raw materials are mined. There are deposits of tungsten and beryllium ore.

A few kilometers from Satka there is a unique deposit of rare metal ores, namely zirconium, niobium, tantalum, molybdenum, which is called Simbirka. This ore has an unusual mineral composition and is very rich in tantalum and niobium, which is extremely rare.

To date, a map of the mineral resources of the Urals has been compiled, which is constantly updated as new searches and development of deposits are carried out.

MUNICIPAL EDUCATIONAL INSTITUTION

"SECONDARY SCHOOL OF THE VILLAGE OF BEREZINA RECHKA

SARATOV DISTRICT OF SARATOV REGION"

Abstract on geography

"Natural Resources of the Urals"

Work completed

9th grade student

Fedotov Vladislav

Head: teacher

Geography Ponomarev

Tatyana Yuryevna.

Natural resources of the Urals

The Ural Mountains amaze with the richness of their subsoil, which has given them the reputation of being the underground storehouse of our country. About a thousand different minerals have been found here and over 10 thousand mineral deposits have been recorded. In terms of reserves of platinum, asbestos, precious stones, and potassium salts, the Urals is one of the first places in the world.

For thousands of years, the Ural Mountains have been subject to destruction under the influence of external forces - weathering, ice and river flows. As a result, the inner parts of the folds appeared near the surface, where mineral formation processes took place intensively and various ores arose. Thus, the long-term destruction of the mountains “exposed” rich mineral deposits and made them available for development.

The main wealth of the Urals is ores, and often complex ores, for example, iron ores with an admixture of titanium, nickel, chromium, copper ores with an admixture of zinc, gold, and silver. Most of the ore deposits are located on the eastern slope, where igneous rocks predominate. Large deposits of iron and accompanying ores are Magnitogorskoye, Vysokogorskoye, Kachkanarskoye, Bakalskoye, Khalilovskoye.

The Urals are also rich in deposits of non-ferrous metals. Copper ore is mined at Krasnouralskoye, Gaiskoye and other deposits. Large deposits of bauxite and manganese were found in the Northern Urals. A lot of nickel and chromium are mined in the Urals. In the mountains of the Middle and Northern Urals there is a platinum belt with primary and alluvial platinum deposits. Gold is associated with quartz veins of granites on the eastern slope. The Berezovskoye deposit near Yekaterinburg is the oldest gold mining site in Russia.

Among the non-metallic resources, it is worth noting the huge deposits of asbestos (“mountain flax”) - the most valuable fire-resistant material. The Bazhenov asbestos deposit is one of the largest in the world. The Shabrovskoe talc deposit is the largest in our country. Also on the eastern slope of the mountains there are deposits of graphite and corundum.

The Urals have long been famous for all kinds of precious and ornamental stones. Famous Ural gems include amethysts, smoky topazes, morions, green emeralds, sapphires, transparent rock crystal, alexandrites, demantoids and others. All these gems are mined mainly on the eastern slope (Murzinka mines, Ilmen Mountains). High-quality diamonds were found on the western slope in the Vishera River basin. The ornamental stones of the Urals are distinguished by their extraordinary beauty of colors: jasper, marble, variegated coils. But green patterned malachite and pink eagle are especially prized.

In the Cis-Ural region, the Permian salt-bearing strata of the marginal trough contain colossal reserves of potassium salts, rock salt, and gypsum (Verkhnekamskoye, Sol-Iletskoye, Usolskoye deposits). There are also a lot of building materials in the Urals - limestone, granite, cement raw materials.

In many areas of this mountainous country, refractory materials necessary for metallurgy are mined. Development of refractory clays, kaolin, and quartzites is underway. The Satka magnesites are especially valuable in the Southern Urals. There is also oil in the Urals (Ishimbay and others), as well as coal. In addition to mineral resources, the Urals are famous for their forest resources. There are especially many forests in the Northern Urals.

Flora and fauna

The composition of the four-legged and feathered inhabitants of the Urals is diverse, but has much in common with the flora and fauna of the neighboring plains. Mountainous terrain increases this diversity, causing the appearance of altitudinal zones in the Urals and creating differences between the western and eastern slopes

As you move south, the altitudinal zonation of the Urals becomes more complex. Gradually, the boundaries of the belts rise higher and higher along the slopes, and in their lower part, when moving to a more southern zone, a new belt appears.

Flora. To the south of the Arctic Circle, larch predominates in the forests. As it moves south, it gradually rises along the mountain slopes, forming the upper boundary of the forest belt. Larch is joined by spruce, cedar, and birch. Near Mount Narodnaya, pine and fir are found in the forests. These forests are located mainly on podzolic soils. There are a lot of blueberries in the grassy cover of forests. On the western slope of the Southern Urals, more heat-loving flora grows: oak, beech, hornbeam, hazel.

The fauna of the Ural taiga is much richer than the fauna of the tundra. Elk, wolverine, sable, squirrel, chipmunk, weasel, flying squirrel, brown bear, reindeer, ermine, and weasel live here. Otters and beavers are found along the river valleys. New valuable animals have been settled in the Urals. The sika deer has been acclimatized in the Ilmensky Reserve; muskrat, beaver, deer, muskrat, raccoon dog, American mink, and Barguzin sable have also been resettled.

In the Urals, based on differences in altitude, climatic conditions, and geological development, several parts are distinguished: Polar, Subpolar, Northern, Middle and Southern Urals.

Rivers and lakes of the mountainous country

On the Ural ridge, separating the water basins of the Volga and Ob, many large tributaries of these rivers originate: the Vishera, Chusovaya, Belaya, and Ufa flow to the west; to the east - Northern Sosva, Pelym, Tura, Iset. In the north, the Pechora begins, flowing into the Arctic Ocean, and in the south, the Ural River flows through Kazakhstan and flows into the Caspian Sea. No wonder the gray-haired Ural is called the keeper of river sources

Lakes play a significant role in the landscapes of the Urals, and for some areas, for example, the forest-steppe Trans-Urals, lake landscapes are even typical. In some places large accumulations of “blue saucers” are visible here, separated by narrow isthmuses of land. There are many lakes in the eastern foothills of the Southern and Middle Urals and among the swampy taiga of the northern Trans-Urals. In the mountainous country there are fresh, brackish, and even bitterly salty lakes. There are also karst lakes, and there are floodplain oxbow lakes and lakes of fog.

The fish in the rivers and lakes of the Urals is tasty and often valuable. Among the Ural inhabitants of reservoirs there are European grayling, whitefish, burbot, ide, brook lamprey, taimen, sculpin goby, salmon, pike, perch, roach, crucian carp, tench, carp, pike perch, and trout.

Lake Turgoyak

It is rare that on our planet there are simultaneously mountains, a lake in these mountains, and a coniferous forest all around. One of such places here in the Southern Urals is Lake Turgoyak, now a national park. In terms of cleanliness and transparency of the water, it is not inferior to Lake Baikal. The lake is included in the list of the most valuable reservoirs in the world by the International Limnological Commission. In our country it is included in the card index of remarkable landscapes. The area of ​​the lake is 26.4 sq. km, length - 6.9 km, greatest width - 6.3 km, coastline length 27 km. Turgoyak is located in a deep intermountain basin between the Ural-Tau and Ilmensky ridges at an altitude of 320 m above sea level. This is the deepest lake in the Southern Urals: its depth reaches 34 m, the average depth is 19.2 m. There are six islands in total on the lake. Large rivers flow into the lake: Bobrovka, Kuleshovka, Lipovka and Pugachevka. Only one river flows out - Istok. Currently, due to the decrease in the water level in the lake, there is no outflow of water. It itself is very picturesque; walking trails are laid along its banks.

There are many beautiful places on the lake. The Inyshevsky Bay is especially beautiful on the northern shore, always quiet and thoughtful, even when there are waves on the lake; wide layers of sand stretch from the water in an arc, from rock to rock.

It is interesting to visit its islands. The largest of them is the island of St. Vera, where at one time there was an Old Believer monastery.

It is interesting to climb deep into the bay near the Krestovoy Peninsula and from there climb Krestovaya Mountain. Beautiful view from Krestovaya Mountain.

Another beautiful excursion is to the Ilmensky ridge. From the top there is a view to the east, to the eastern Ural region of lakes scattered everywhere among the wooded hills. Directly in front of us the winding Miassovo stretches whimsically, far to the right is the wide, patterned B. Kisegach, even further to the right you can barely see Chebarkul. Large, small, barely noticeable light depressions in the forest.

A long journey can be made to Itsil.

On the shore of Lake Turgoyak, there are dozens of sanatoriums. boarding houses and recreation centers.

The unique nature of the Urals

“A person will admire the wild virgin taiga, where there is so much life and freedom. And if fate throws this person onto lakes, winding rivers, rolling their crystalline waters along a rocky bottom, and he hears the cry of birds - geese, ducks, seagulls, - sees flocks of “red” game fluttering in all directions - he will be sorry to leave with a region where, although for a relatively short time, nature is full of enchanting charm.”

A. K. Denisov-Uralsky

Naturally, the nature of such a large mountainous country as the Urals, stretching from the Arctic Ocean to the southern steppes in the center of a huge continent, is unusually diverse. The Urals crosses several natural zones, clearly expressed on the neighboring plains - Russian and West Siberian.

Within the same zone on the plains of the Cis-Urals and Trans-Urals, natural conditions differ markedly. This is explained by the fact that the Ural Mountains not only form a barrier to the settlement of some species of plants and animals, but also serve as a real climatic barrier. To the west of them there is more precipitation, the climate is more humid and mild; to the east, that is, beyond the Urals, there is less precipitation, the climate is drier, with pronounced continental features.

The nature of the vegetation of the Cis-Urals and Trans-Urals is also different. For example, in the taiga of the Cis-Ural region there are most fir-spruce forests, and fewer pine forests. In the Trans-Ural region, on the contrary, pine forests are especially common. In the Cis-Urals, south of the taiga, there are broad-leaved forests; in the Trans-Urals there are none. In the steppes of the Cis-Ural region, in the remaining areas of meadow steppes, forbs form a colorful carpet. In the steppes of the Trans-Ural region, due to the lack of moisture and the close occurrence of salt-rich tertiary sediments, saline soils with sparse vegetation are common.

Currently, there are practically no natural landscapes left in the Urals, with the exception of forests and mountain tundras in the very north, which would not be changed by man. In the forest zone, in place of native dark coniferous and pine forests, birches and aspens grow over vast areas. The fauna of the Urals has also changed greatly: the number of ferrets, badgers, squirrels, sables, martens, and beavers has decreased. There are few fish left in the rivers.

As a result of economic activity, the nature of the Urals, especially the Middle and Southern ones, has changed greatly. The forests suffered significantly, as they were cut down when the metallurgy of the Urals developed using charcoal. The composition of the forest area has changed: more and more space is occupied by birch and birch-pine forests. Many rivers are polluted by industrial wastes, and in large cities there is a lack of clean water for the household needs of the population, so the problem of water supply is one of the most important in this region. Soil resources are rich only in the southern part of the Urals, in the zone of steppes and forest-steppes. All of the above facts allow us to conclude that the problems of rational use of the natural resources of the Urals are very acute.

Bibliography

1. Lobanov Yu. E. “Ural caves”. Sverdlovsk: Middle Ural book. Publishing house, 1989

2. Pysin K. G. “On the natural monuments of Russia.” M.: Soviet Russia. 1990

3. Arkhipova N. P. “Wildlife places of the Sverdlovsk region.” – Sverdlovsk: Middle Urals. Book Publishing house, 1984

Illustrations used:

http://priroda-foto.ru/kartinki-prirodi-urala.html

http://www.geo.59311s011.edusite.ru/p50aa1.html

http://forum.kinozal.tv/showthread.php?s=7c74edb8ffee304754af3f1ec682dd29&t=119840&page=3

http://greeninform.ru/2009/03/malaxit-kamen-garmonii/

http://www.suvenirograd.ru/sights.php?id=1462&lang=1

http://www.spas-extreme.ru/el.php?EID=1200

The Urals are one of the unique iron ore provinces of the world, including all the diversity of iron ores both in the method of formation and in their qualitative characteristics. Approximately from the second half of the 16th century, handicraft iron mining existed in many places along the western and eastern slopes of the Ural ridge. At that time, only fusible brown iron ore was sought and mined, which was formed as a result of the deposition of iron from underground groundwater to the bottom of numerous swamps. Deposits of such or lake ores were numerous, but very insignificant in reserves and therefore were quickly developed. The discoverers and users of these ores were mostly peasants, who received the so-called “brick” iron in the form of a spongy mass at a temperature of 700–800 o C in “houses”.

The increased needs of the state in the era of Peter I in arming the army led to the widespread development of prospecting for higher quality raw materials and the construction of iron-making state-owned factories near open deposits. At that time, the Demidovs were actively engaged in the search for iron ore and the construction of new factories in the Urals. To control the activities of miners, Peter I sent V.N. Tatishchev and V.I. Gennin to the Urals, who founded many new mines and factories in the Urals. From smelting brown iron ore, factories began to switch to smelting magnetic iron ore. These were skarn magnetite ores, which for a long time determined the industrial significance of the Ural region: for more than two centuries they were the main base of the metallurgical industry of the Urals and throughout Russia. But to date, the reserves of large shallow deposits have been depleted, and industry is faced with the problem of developing poor and even more refractory (due to their higher titanium content) ores - titanomagnetite. With the development of titanomagnetite ores in the early 70s (1963), the third period began in the development of the metallurgical industry in the Urals.

Huge reserves of titanomagnetite ores, the presence of a valuable alloying element - vanadium, and good concentration are favorable objective prerequisites for the further development of the ferrous metallurgy base of the Urals in the new millennium. Currently, in the Urals there are about 50 medium and large iron ore deposits and more than 200 small deposits and ore occurrences. Their formation is associated with various geological processes: magmatic, post-magmatic, sedimentary, weathering. Depending on the conditions of ore formation, their mineral composition, geochemical features and connection with certain complexes of ore-hosting rocks, the following main types of deposits are distinguished: titanomagnetite, skarn-magnetite, siderite, ferruginous quartzite and brown ironstone.

Titanium magnetite deposits

Deposits of titanomagnetite ores have been quite well studied, a major contribution to their study was made by M.I. Aleshin, P.S. Pryamonosov, A.F. Fadeichev, D.S. Steinberg, V.G. Fominykh, B.M. Aleshin and others Two groups (formations) of titanomagnetite deposits are distinguished: ilmenite-magnetite (high-titanium ores), or Kusa subtype, and titanium-magnetite proper (low-titanium ores), or Kachkanar subtype.

The high-titanium group of deposits of the Kusinsky subtype is distributed within the Central Ural zone on the western slope of the Northern Urals (Yubryshkinskoye) and the Southern Urals (Kusinsky-Kopan group). These deposits occur among gabbro and gabbro-norites, less commonly pyroxenites and amphibolites. Vein diabases are widely developed in the massifs, so researchers attribute such an ore-hosting complex to the gabbro-diabase formation, formed at the stage of riftogenic extension of ancient stabilized areas (platforms). Ilmenite-magnetite mineralization is concentrated exclusively within intrusive massifs in the form of vein- and lens-shaped bodies of solid ores and surrounding halos of disseminated ores. Such ore zones are usually characterized by small thicknesses (tens of meters), but at the same time they have a very significant extent along strike (hundreds of meters) and tap out at a depth of the first hundreds of meters. The strike and fall of ore deposits, as a rule, are consistent with the banding of the host gabbroids and often follow the contours of the ore-hosting massifs, which indicates the genetic conjugation of the processes of ore formation and intrusive magmatism.

Zones of continuous ore and ore dissemination occupy different positions in the massifs and do not reveal any clearly defined pattern in this. Thus, the main ore zone at the Kopan deposit gravitates towards the recumbent side of the massif, and at Matkal – along the entire section. The main ore minerals of the deposits of the described group are ilmenite (FeTiO 3) and titanomagnetite (Fe 3 O 4 with an admixture of TiO 2 up to 14%), sulfides are present in small quantities: pyrite (FeS 2), chalcopyrite (CuFeS 2), pyrrhotite (FeS) ; from non-metallic minerals - amphibole, pyroxene, plagioclase, epidote, zoisite, clinozoisite, chlorite, olivine, biotite, apatite. Depending on the quantitative ratio of the main ore minerals, ilmenite, ilmenite-titanomagnetite and titanomagnetite ores are distinguished. As established by D.S. Steinberg, the amount of ilmenite in relation to titanomagnetite in ores increases from solid ores to disseminated ores and from the recumbent side of the ore zone or massif to the hanging one.

According to the chemical composition, the ores of the deposits under consideration are high-titanium. The titanium and, to a lesser extent, vanadium contents correlate with the iron content in ores. Thus, in disseminated ores (with an iron content of 20–25%) TiO2 concentrations are 4–6%, in solid ores (with an iron content of 50–55%) – from 8 to 14%. A similar, but less clear, pattern is observed in the distribution of vanadium, this valuable alloying element, the content of which in disseminated and solid ores is 0.5 and 0.8%, respectively. Ores of this type of deposits are considered difficult to process due to the large number of thin lamellar ilmenite ingrowths in titanomagnetite. The predicted resources of ores of this type in the depth range of 0-700 m are estimated at 6 billion tons.

The greatest importance for industry at present are and will be in the new millennium, undoubtedly, deposits of low-titanium titanomagnetite ores of the Kachkanar subtype, confined mainly to the dunite-pyroxenite-gabbro formation of the Platinum Belt, located in the western part of the Tagil zone. The age of the deposits is Middle Paleozoic. The geological structure and patterns of location of low-titanium ore deposits are described in a number of works by V.G. Fomins.

The most significant deposits of this group are Kachkanarskoye, Gusevogorskoye and Suroyamskoye. Mineralization is associated with various types of rocks: at Visimskoye and in certain zones of the Gusevogorskoye deposit - with the most magnesian varieties of ultrabasic (low-silica) rocks - olivinites and wehrlites, in such deposits as Kachkanarskoye, Gusevogorskoye and others - with pyroxenites, at Pervouralskoye and Mayurovskoye - with the Hornblendites. In general, low-titanium ores have a disseminated or schlieren structure, gradually transitioning into the interfering rocks. Ore deposits are characterized by slab-, nest-, stock- and complex irregular shapes. Ore minerals are mainly represented by magnetite and ilmenite; hematite and sulfides are present in minor quantities, and scattered platinum is found. The content of useful components in the ores is as follows: Fe – 16–36,%: TiO 2 – 0.5–2, V 2 O 5 – 0.13 – 0.17. The ores also contain other alloying elements that may be of industrial interest in the future (scandium, germanium), as well as platinum group elements.

The share of low-titanium ores in the total balance of iron ores in the Urals accounts for more than 80%. Their largest representative is the Kachkanar group, which includes the Kachkanar and Gusevogorskoye deposits themselves, located in the Kachkanar massif. The latter has a rounded shape with a diameter of 11 km and is composed of clinopyroxenites and gabbroids. Ore deposits are confined to areas of pyroxenite development. Ore minerals are represented by magnetite of several generations, of which the most important is titanomagnetite, which fills the intergranular spaces and determines the sideronite structure; ilmenite, present in the form of thin plates, pyrite, chalcopyrite, pentlandite, bornite and extremely rarely platinum group minerals in the form of small segregations intergrown with olivine, pyroxene and titanomagnetite.

The explored ore reserves of the Kachkanar group deposits amount to 6 billion tons, the predicted resources exceed 12 billion tons. Huge reserves and favorable geological, mining and technological conditions for their development are prerequisites for the fact that in the near future they will become the main iron ore base of the ferrous metallurgy of the Urals . The genesis of low-titanium vanadium-containing ores is currently debatable; Some researchers speak in favor of the magmatogenic hypothesis, others – the magmatic-metasomatic one.

Skarn-magnetite deposits

Skarn-magnetite deposits are the main raw material base for the mining and metallurgical industries of the Urals. The largest deposits are concentrated in two geological-structural zones: Tagilo-Magnitogorsk - Goroblagodatskoye, North Goroblagodatskoye, Vysokogorskoye, Estyuninskoye, Magnitogorskoye, Maly Kuibas and East Ural - Petrovskoye, Glubochenskoye, Aleshinskoye, Kacharskoye, Sokolovsko-Sarbaiskaya group.

Over the period of more than 250 years of exploitation of deposits of this type, production and scientific teams of various organizations and departments have carried out extensive geological and geophysical research to clarify the geological structure of the Ural deposits and the conditions of their formation, the patterns of placement and localization of mineralization within ore fields, ore-bearing structures and ore deposits. zones, elucidating the role of various forms of magmatism and metasomatism in the formation of iron ore deposits. A large role in these studies belongs to the Ural teams of geologists and geophysicists of the PGO "Uralgeology", headed in different years by M.I. Aleshin, B.M. Aleshin, E.M. Ananyeva, K.E. Kozhevnikov, N.P. Kuskov, P.S.Pryamonosov, S.I.Biryuchev, as well as scientific staff of the Institute of Geology and Geochemistry of the Ural Scientific Center L.N.Ovchinnikov, Y.P.Baklaev, V.A.Dunaev, N.D.Znamensky, M.A. Karasik, G.B. Fershtatter, D.S. Steinberg and others.

In the study of the Turgai group of deposits located in the East Ural zone, a large role belongs to the work of scientific teams of institutes in Almaty, St. Petersburg and Rudny: A.E. Bekmukhametov, N.M. Belyashov, A.I. Ivlev, A. K. Kaimakova, P.N. Kobzar, I.A. Kochergina, A.E. Mazina, O.K. Ksenofontova, G.S. Porotova, N.I. Rudenko, D.D. Toporkova. The theoretical foundations of the processes of skarn ore formation were laid by our outstanding scientists - academicians A.N. Zavaritsky and D.S. Korzhinsky in the 30-40s. Later, in the 60s, some provisions of this theory were developed in the works of V.A. Zharikov and L.N. Ovchinnikov. In the last 15-20 years, thanks to detailed geological-petrological and mineralogical-geochemical research by the staff of the Institute of Geology and Geochemistry of the UC A.M. Dymkin, Yu.A. Poltavets, V.V. Kholodnov, G.S. Nechkin, Z.I. Poltavets and others significantly detailed ideas about the genesis of skarn-magnetite deposits, the role of volcano-plutonic magmatism in the process of their formation, and revealed the nature of the dependence of the scale of mineralization on the composition and chemistry of volcano-plutonic associations and the degree of their metasomatic changes.

In the last decade, employees of the PGO "Uralgeology" M.S. Rapoport and N.I. Ruditsa, based on geological and geophysical data, have done a lot of work to establish the patterns of location of iron ore deposits in connection with the peculiarities of the deep structure of the ore-bearing zones of the Urals. Extensive literature is devoted to the description of the geological structure of skarn-magnetite deposits, the patterns of their location and formation conditions, and the identification of ore-controlling factors.

The skarn-magnetite deposits of the Urals are very diverse in geological, structural and morphological features, the nature of their connection with intrusive magmatism, and the nature of their distribution within ore zones. The overwhelming majority of them were formed in the Upper Silurian-Lower Devonian (Tagil-Kushvinsky ore district), Lower-Middle Devonian (Auerbaho-Turyinsky ore district) and Upper Tournaisian-Serpukhovian (Magnitogorsk ore zone and Valeryanovskaya ore zone of the Tyumen-Kustanai trough in the Trans-Urals). Skarn-magnetite deposits are located in the Urals in the form of linearly elongated ore belts or zones. The linear arrangement of the zones is due to the belt alternation of structural-formational zones, reflecting the linear-folded structure of the Urals. Within ore zones, deposits are distributed unevenly or discretely in the form of separate ore districts or ore clusters associated with centers of basaltoid magmatism. These centers are predominantly separate structural-tectonic blocks, limited, as a rule, by faults. The structure of such blocks, due to their unequal tectonic mobility, differs markedly, which affects the nature of volcano-plutonic magmatism and associated mineralization. Ore areas (blocks) with large deposits are characterized by increased thicknesses of effusive-pyroclastic and volcanic-intrusive formations with increased alkalinity, including potassium content.

Most skarn-magnetite deposits occur among sedimentary-volcanogenic rocks: tuffaceous sandstones, tuffites, limestones, effusives of various compositions with different quantitative ratios of sedimentary and volcanogenic formations. The volcanic rocks have a predominantly basaltic, andesite-basalt, andesite composition. Together with their intrusive analogues, they form comagmatic complexes that make up volcano-plutonic structures (VPS). The nature of magnetite mineralization, i.e. The morphological features and structure of ore deposits, the composition of the ore and the degree of change in the wall rocks, which in turn determine the type of deposit, the intensity and scale of mineralization, are largely determined by its position in the volcanic-plutonic structure, i.e., it depends on the depth of the ore-forming process. Based on the predominant mineral associations in the ores and the near-ore changes in the host rocks, several subtypes are distinguished among skarn-type deposits: late magmatic magnetite, skarn, scapolite and hydrosilicate; transitions between them are also possible. They are formed at different depth levels. The following depth levels are conventionally distinguished in the UPS: hypo-mesoabyssal – 3 – 5 km, hypabyssal – 1 – 3 km, subvolcanic<1 – 1,5 км и приповерхностный <1 км.

At the hypo-mesoabyssal level, in the deepest root parts of the UBL, late magmatic magnetite deposits are formed, localized directly in the intrusive massif. These include such deposits as Maly Kuybas, Aleshinskoye, Davydovskoye. Ore deposits are represented by disseminated magnetite and titanomagnetite mineralization in gabbro, gabbro-diorites, and less commonly diorites, which is isolated in the form of separate lens-shaped zones, less often veinlets and schlieren-like accumulations.

The ore impregnation zones extend for hundreds of meters. The transition from rocks with rich ore inclusions to barren rocks is gradual. Intrusive formations are superimposed by postmagmatic processes, expressed in the development of albitization, scapolization, and actinolitization, often spatially combined with ore zones. In addition to the listed ore minerals, ilmenite, spinel, hematite, pyrite, and rarely chalcopyrite are typical. The chemical composition of titanomagnetite contains an increased content of vanadium. Deposits of this subtype are distinguished by small reserves. At the hypabyssal level of the IPN, the skarn subtype itself is formed, the most common in the Urals.

It includes the deposits of the Magnitogorsk, Tagilo-Kushvinsky, Auerbaho-Turinsky, Sokolovsko-Sarbaysky and other ore fields. The geological section of this level is characterized by the widespread development of intrusive rocks of basic and intermediate composition along with the volcanic-sedimentary complex. The vast majority of skarn ore bodies are localized directly in the contact aureole of intrusive massifs, replacing carbonate-containing layers of sedimentary and volcanic-sedimentary rocks. Ore deposits in the deposits are represented by both gently dipping and steeply dipping bodies, the latter mostly confined to faults. Occasionally, skarn-magnetite ore deposits are located in bay- and bay-shaped depressions of intrusions, forming bodies of irregular shape. The dimensions of ore bodies vary along the strike from tens to many hundreds of meters, and in thickness - from a few meters to 150-200 m. The mineralogical composition of the ores here is more diverse than in other types of ores and is represented by magnetite, pyrite, chalcopyrite, pyrrhotite, cobaltine, sphalerite, bornite, galena and other sulfides and oxides, as well as native Ag. In addition, sulfides contain an increased content of noble metals: Au up to 6 g/t and Ag up to 37 g/t.

In many ore fields, temperature mineralogical zoning is observed in the distribution of ore minerals, which is expressed in the formation of sulfide-magnetite ores (cuprous magnetites) on the flanks of skarn-magnetite deposits. Thus, in the Auerbakh-Turyinsky ore field on the flanks of the Peschansky, Auerbakhovsky, West Peschansky, Vorontsovsky deposits in the same geological and structural setting, ore bodies of sulfide-magnetite ores with reserves of 4-5 million tons with an average copper content of 0.7-1 .6% and iron 42-45%. Sulfide ores, in addition to iron and copper, often contain cobalt, gold, and silver in significant quantities and, therefore, are complex raw materials.

In deposits at the hypabyssal depth level, metasomatic zoning of two types is well manifested. The first is characteristic of deposits located directly in the exocontact zone of intrusive massifs. Here, with distance from the contacts of intrusive bodies, higher-temperature zones are replaced by low-temperature ones in the following order: magnetite ores, ore pyroxene-garnet skarns, barren pyroxene-garnet skarns, pyroxene-albite-epidote metasomatites. In the same direction, the contents of ore elements - Ni, Co, Cu - decrease in geochemical halos and the contents of Ni, V, Zn, Pb increase. The second type of metasomatic zoning is characteristic of deposits located at a considerable distance from intrusive massifs, where ore-bearing fluids were unloaded in tectonically weakened zones. Here zoning is formed with the centrifugal growth of zones of the metasomatic column.

Usually around each ore body towards the hanging and footwalls there are successively located: zones of disseminated ores, ore and barren skarns, pyroxene-scapolite, pyroxene-albite metasomatites and weakly altered propylitized rocks. In the geochemical aureole, the trend of decreasing contents of ore elements is directed from massive magnetite ores towards the hanging and recumbent sides of deposits: in this direction the contents of Ni, Co, Cu decrease and Ni, V, Zn, Pb increase. This behavior of accompanying elements is due to the temperature gradient of the environment in which skarn-ore-forming processes occur, and the differential mobility of these elements in high-temperature ore-forming hydrothermal solutions. According to the dip of ore deposits, i.e. With increasing depth, there is also a change in the contents of a number of elements, for example, the degree of cobalt content of pyrites increases.

One of the most typical deposits of the skarn subtype, Goroblagodatskoye, is located in the southern part of the Pokrovsko-Goroblagodatskoye ore-bearing zone. Skarn-magnetite mineralization is located in direct contact with the Kushva diorite-syenite intrusion and continues north of the contact for 5 km. The ore zone, confined to the east-dipping Goroblagodat strata of the Upper Silurian, also plunges to the east to a depth of 1300 m, without showing signs of pinching out. Here, mineralization is represented by deposits of complex morphology, occurring subconformably with the host rocks. The deposits are traced along strike at a distance of about 1000 m with an average thickness of 10 m and are characterized by bulges with a thickness of 30 to 80 m, which were presumably the stem circulation zones of ore-forming solutions. The composition of the ore is magnetite and sulfide-magnetite.

The near-ore rocks are represented near the intrusive massif by ore and barren pyroxene-garnet skarns and orthoclase-pyroxene-scapolite metasomatites; with a distance from it, albitized and scapolized rocks to varying degrees are predominantly developed. In terms of reserves, the deposit is classified as medium and is currently in the final development stage; the development of ores in the North Goroblagodatsky area due to their deep occurrence is an object of the future.

At the subvolcanic depth level, scapolite, scapolite-skarn, and sometimes hydrosilicate-skarn subtypes of deposits are formed. They are not widely represented in the Urals, but they are interesting because among them there is one unique deposit in the Trans-Urals - Kacharskoye, known for its exceptionally large ore reserves - 2.3 billion tons. The Osokino-Aleksandrovskoye deposit, which is smaller in terms of ore reserves, belongs to the same type in the Tagilo-Kushvinsky ore district, the Berezovskoye deposit, the Okunevskoye and Barzhagsinskoye ore occurrences in the Trans-Urals. The last two may also represent very large deposits, comparable in ore reserves to Kacharsky, but located at great depths (more than 1500-2000 m).

The geological section of this level is characterized by the predominant development of sedimentary-volcanogenic rocks. Intrusive bodies are few in number and are represented by dike or subvolcanic facies. Ore deposits are usually of great extent and are characterized by stratiformity with a wide development of near-ore scapolite metasomatites, in which most of the ore reserves are often concentrated. Ore mineralization is represented mainly by magnetite, hematite, and pyrite. The most developed of the near-ore metasomatic formations are scapolite metasomatites with a sharply subordinate amount of pyroxene-garnet skarns, pyroxene-albite, epidote-prehnite-albite-chlorite and actinolite-chlorite rocks. Scapolite metasomatites of large deposits are characterized by high chlorine content (up to 3.6% Cl in scapolite and more than 1% in apatite), and the ores contain increased Ti and V contents compared to typical skarn ores.

At the near-surface depth level, a hydrosilicate subtype of deposits is formed. These include the Kurzhunkulskoye, Sharakolskoye deposits, and the Eltai group in the Trans-Urals. As a rule, the deposits occur among volcanogenic and volcanogenic-sedimentary rocks and belong to the medium- and low-temperature epidote-actinolite-chlorite facies of metasomatic alterations. Ore bodies are characterized by stratiformity and are composed of continuous massive, banded, spotty-disseminated and brecciated ores. Ore zones can be traced at a distance of 2000 m or more and a width of several hundred meters. Ores of this type consist of magnetite, hematite, musketovite, pyrite, chalcopyrite, marcasite in association with actinolite, epidote, albite, chlorite, and calcite. Magnetite, which usually has an allotriomorphic granular structure in all described types of deposits, is often collomorphic here. Some researchers believe that such deposits were originally hydrothermal-metasomatic; others suggest their primary volcanogenic-sedimentary (exhalation-sedimentary) nature and their subsequent metasomatic transformation. Deposits of this type are few in number, ore reserves are small, as a rule, up to 100–150 million tons.

For the formation of skarn-magnetite ores and thick zones of near-ore alterations, it is necessary to maintain for a long time (on the order of hundreds of thousands, perhaps up to the first millions of years) high-temperature heating of the host rocks and an intense fluid flow - a high-temperature hydrothermal (aqueous) solution saturated with many ore and acidic components . For a long time it was believed that such a source of heat, as well as ore-forming fluids and partly ore matter, were intrusions located within the deposits; The host volcanics were usually considered the main source of ore matter. However, recently a number of researchers have shown the insufficiency of these ideas to explain the conditions for the formation of large post-magmatic deposits. Currently, the formation of deposits, especially large ones and unique in terms of ore reserves, is increasingly associated with ascending intratelluric fluid flows rising from great depths along tectonically weakened zones, which are usually associated with intrusions, subvolcanic dikes and volcanic apparatuses. In this case, intrusions, especially those that have relatively steep contacts with their host rocks, become only conductors of ore-forming solutions from underlying and deep-lying ore-generating centers in the mantle.

At the current level of knowledge about the structural-geological and geological-genetic features of all the largest deposits of the Urals, one can confidently assert that all the main types of magnetite deposits of the skarn formation can be caused not only by the post-magmatic activity of intrusive magmatism, but equally by volcanism (volcano-plutonism ), and the evolution of intratelluric fluid flows. Based on the various relationships between the roles of intrusive magmatism, volcanism and mantle intratelluric fluids in the processes of ore formation, it is possible to quite adequately characterize the geological and genetic features of the magnetite deposits of the Urals and present them in the form of a corresponding “homologous” series, in which various types of deposits, from late magmatic and typically skarn contact-metasomatic to scapolite and volcanic-sedimentary, are considered from the point of view of reducing the role of intrusive magmatism in the process of their formation and increasing the role of mantle fluids

The skarn-magnetite ores of the Urals, together with titanomagnetite ores, serve as the main raw material base for the metallurgical enterprises of the Urals. The complex composition of skarn sulfide-magnetite (Cu, Co, Zn, partly Au, Ag) and titanomagnetite ores (Ti, V, partly Sc and platinum group metals), the improvement of old and the introduction of new enrichment technologies in the future should undoubtedly contribute to increasing the efficiency of iron ore mines. mining and processing enterprises of the Urals. Thus, according to the estimates of employees of the Uralmekhanobr Institute, the total cost of associated elements (Co, Cu, Au, Ag and S) in skarn sulfide-containing ores of some deposits of the Tagil-Kushvinsky ore district is more than half the cost of iron in these ores. At the same time, due to long-term and intensive exploitation, especially in the war and post-war decades, the reserves of skarn magnetite ores have greatly decreased: almost all of the largest deposits in the Middle and Southern Urals - Goroblagodatskoye, Vysokogorskoye and Magnitogorskoye - are in the final stage of development. The situation with reserve reserves was also greatly complicated due to the collapse of the USSR, as a result of which the main group of the largest developed skarn magnetite deposits in the country and in the world, the Sokolovsko-Sarbai group and Kacharskoe, went to Kazakhstan. There are very large reserves of skarn ores in the Kurgan region, but they lie at great depths (470–1500 m) and are unlikely to be exploited in the near future. The most realistic directions for increasing ore reserves in economically developed areas seem to be additional exploration and search for ores on deep horizons and flanks of known deposits.

Siderite deposits

Industrial deposits of siderite are known in the west of the Chelyabinsk region - Bakalsky in the Satka region and Akhtenskoye in the Kusinsky region. They are located in the Central Ural structural-geological zone in the northern part of the Bashkir meganticlinorium. Siderite deposits belong to the hydrothermal-metasomatic class and occur in carbonate rocks. The Bakal group of siderite deposits is the largest in the world for this class.

The Bakal deposits are located in the carbonate-terrigenous rocks of the Bakal Formation of the Lower Riphean. The latter consists of two subformations: the lower (Makarovskaya) sandy-clayey with a thickness of 600 m and the upper (Malobakalskaya), consisting of 5 cycles - alternating members of terrigenous-clayey and carbonate composition with a total thickness of 900 m. The ore-bearing formation conformably overlies the carbonate rocks of the Satka formation, overlaps with angular (about 15o) and stratigraphic unconformity by quartzite-like sandstones of the Middle Riphean Zigalga Formation with a thickness of 60-80 m. Above lies a thick sandy-shale formation of the Middle Riphean Zigazino-Komarovsky Formation. The structure of the ore field is a syncline 8-12 km wide with a northwestern strike, complicated by numerous tectonic disturbances of a reverse-fault nature with an amplitude of up to 500 m and small folds. Up to 85% of the reserves of siderite ores located in carbonate members are confined to the surface of the overlying quartzite-like sandstones. Igneous rocks in the ore field are represented by pre-ore and post-ore diabase dikes.

Iron ores of the Bakal deposits are represented by two types: epigenetic siderite deposits and brown iron ores of siderite oxidation zones. The deposits have been developed for about 240 years and high-quality brown-iron ores have been largely worked out. Siderite reserves amount to about 1 billion tons, which allows us to consider the Bakal deposits as unique. In the ore field with an area of ​​150 km2, more than 20 deposits are known, containing about 200 ore bodies. Deposits are identified along the boundaries of large tectonic faults.

Siderite deposits have a sheet-like and lens-shaped shape. The dimensions of the ore bodies reach a length of up to 2–3 km, a maximum thickness of 80 m, and have both gentle and steep bedding.

Siderite is an iron carbonate (FeCO3) with an isomorphic admixture of magnesium in the amount of 5–12% (up to 19%) and belongs to the isomorphic series of sideroplesite - pistomesite minerals. There are several mineral types of ores: 1) high-quality monomineral ores, 2) bimineral with an admixture of ankerite, and 3) polymineral with an admixture of ferruginous dolomite and calcite. Monomineral ores contain more than 30% FeO (up to 49%), 1.5–2% MnO and no more than 1.5–2% CaO. The admixture of sulfur and phosphorus is less than 0.05%. Ore deposits are composed mainly of mono- and bimineral ores, with the former predominating in the upper parts of the deposits, and polymineral ores forming the flanks of ore bodies. Siderite deposits in limestones always have a zone of contact metasomatic dolomites. The contacts of the ore bodies are stepped, blunt, metasomatic, cutting the layering (M.T. Krupenin, 1999). Within the siderite deposits, several manifestations of sulfide-polymetallic (with galena, sphalerite, barite) and copper (chalcopyrite) mineralization were also discovered (V.A. Timeskov, 1963).

Currently, there are three mines that extract siderite ore by open-pit mining: Novobakalsky, Irkuskan, Shuydinsky (the latter also produces the remains of high-quality hematite-hydrogoethite ores - turyites) and the Sideritovaya mine. In total, during the operation of the Bakal mines in the 20th century, 105,647 thousand tons of siderites and 130,464 thousand tons of brown-iron ores were mined, i.e. in total more than 236 million tons of iron ore (N.V. Grinshtein, 1997). In Bakala there is a sinter plant producing sinter from a mixture of siderite and brown iron ore. The prospects for the development of the Bakal deposits should be determined by the integrated use of the natural resources of the ore region.

The Akhtenskoye field is located 30 km east of the city of Kusa. It is confined to the dolomites of the Lower Kusinsky subformation of the Satka formation. Contiguous sheet-like and lens-shaped deposits form a steeply dipping zone up to 2 km long and up to 100 m thick; they have been traced to a depth of up to 400 m. Siderite contains an isomorphic admixture of magnesium (at least 4%) and is characterized by a high quartz content (on average 14%). The deposit's reserves amounted to 10 million tons. They were half mined by open-pit mining.

Deposits of ferruginous quartzites

Known in blocks of ancient Proterozoic metamorphic rocks: Taratashsky, Ufaleysky, Sysertsky, Ilmenogorsk and Saldinsky. Industrial deposits (according to modern requirements) are known in the Taratash block, located in the Central Ural zone, northwest of the city of Zlatoust. The Taratash group includes Kuvatalskoye, Radostnoe, Magnitny Klyuch, Zapadno-Lysogorskoye and Shigirskoye deposits of ferruginous quartzites. Until 1917, ores from these deposits were mined and supplied to the Ufaleysky and Kyshtym metallurgical plants.

Ferrous quartzites of the Taratash deposits occur in the lower part of the Taratash Formation, composed of quartzites, gneisses, and amphibolites. Ore bodies have a sheet and lens shape. They are formed mainly by magnetite, quartz, pyroxene with a small amount of hornblende, garnet, and apatite. The iron content in ores is 30-35%.

The largest of them is the Kuvatalskoye field, located in the northeastern part of the Taratash block. The ore-bearing rocks have a submeridional strike and a western dip at an angle of 20-80°. The ore bodies occur in accordance with the banding of the host rocks. They are torn into several parts (blocks) by faults and displaced relative to each other. The largest ore body was traced along the strike for 1800 m, along the dip - for 850 m with a maximum thickness of 60 m. The ore bodies of the deposit were traced by wells to a depth of 1000 m. Approximate ore reserves to the indicated depth are estimated at 270 million tons (Formations of titanomagnetite ores and ferruginous quartzites, 1984).

Deposits of ferruginous quartzites were formed as a result of metamorphism of sedimentary iron ores, as well as high-ferruginous sedimentary and igneous rocks. During the process of metamorphism, potassium, sodium, calcium, and aluminum were removed from the rocks, and the iron content increased to industrial concentrations.
The Radostnoe deposit, located 15 km southwest of Kuvatalskoye, was mined in an open pit in the late 80s. XX century. Other fields of the Taratash group are not exploited.

Brown iron ore deposits

Among other types of iron ore deposits, which in the future may become one of the important sources of iron due to their large reserves (up to 10 billion tons), exogenous iron ores should be noted. Among them, two subtypes are distinguished: residual and sedimentary. The first subtype includes brown iron ores of the Serov ore region in the Middle Urals and the Orsko-Khalilovsky in the Southern Urals, associated with Mesozoic weathering crusts of ultrabasic rocks. Therefore, they contain high amounts of Cr, Ni and Co and are thus naturally alloyed ores. According to V.I. Leshchikova (1993), the Serovskoye deposit with ore reserves of 770 million tons with an average content of Fe–36.64, Cr–1.70, Ni–0.21 and predicted resources of 900 million tons to a depth of 150 m is quite suitable for open-pit mining.

The second subtype, or oolitic iron ore formation, includes very large deposits with multi-billion-dollar (up to 10 billion tons) reserves of brown iron ores in the Kustanai Trans-Urals. Here, according to A.E. Bekmukhametov (Iron ore formations of the Ural-Tien Shan belt, 1987), they were formed in two different environments: in coastal-marine conditions, ores of the Ayat deposit were formed in Upper Cretaceous deposits, and in continental conditions, in river valleys of the Oligocene ( in the form of narrow hollows) - ores of the Lisakovsky deposit with a length of oolitic ores up to 100 km. These ores are represented by siderite, hydroxides and iron silicates (chamosite, thuringite) and are characterized by low iron content (30–38%), but high contents of silica, aluminum oxide and phosphorus (0.3–0.4%). A.E. Bekmukhametov suggests that the source of the ore material could be both ancient weathering crusts of basic rocks and skarn-magnetite deposits of the Turgai trough.

Among the iron ore deposits of the western slope of the Southern Urals in the territory of Bashkortostan, a large group of small infiltration-residual brown iron ore deposits, occurring in the weathering crust of terrigenous-carbonate strata of the Upper Proterozoic, deserves attention. These deposits are distinguished as the Zigazino-Komarovsky subtype. They were intensively developed back in the 19th century, but by the middle of the 20th century, the operation of most of them was discontinued. The Zigazino-Komarovsky, Avzyansky, Inzersky and Lapyshtinsky iron ore districts, in which more than 30 deposits are located, stand out here.

Iron ores of the deposits are characterized by a relatively simple and uniform material composition, represented mainly by iron hydroxides with a slight admixture of manganese oxides and hydroxides; Some deposits contain iron and copper sulfides - pyrite and chalcopyrite, and at the deepest horizons (more than 100 m) thin layers of siderites are also found.

The most common forms of ore bodies are sheets, lenses, and nests confined to the lower part of the weathering crust. Brown iron ores of the Zigazino-Komarovsky subtype contain Fe 2 O 3 - 42–65%, P 2 O 5 - 0.12–0.18% and S - 0.01–0.02%. The largest is the Tukanskoye deposit, the ore zones of which, consisting of five ore layers, extend along the strike from hundreds of meters to 3 km or more with a thickness of 1 to 10 m. The Beloretsk Metallurgical Plant operates on the ores of the Tukanskoye and Maygashlya deposits. Ores of this subtype constitute the main iron ore base of Bashkortostan, the balance reserves of which are estimated at about 115 million tons and the forecast reserves are about 65 million tons. It should be noted that due to the geological conditions of the placement of iron ores of this type, there are special prospects for the discovery of new industrial deposits according to modern estimates there is no.

In conclusion, it should be said that the experience of studying the patterns of location of iron ore deposits in the Urals and the analysis of the state of the iron ore raw material base of the Urals as a whole indicate that in the Urals there are prospects for discovering new objects at shallow depths (up to 200 m), i.e., shallow-lying large deposits of fusible and easily enriched skarn iron ores are very limited; The predicted resources of these ores are associated with great depths (from 200 to 2000 m). Therefore, titanomagnetite deposits of high-titanium and especially low-titanium ores, characterized by large reserves and occurrence of ores near the surface, are of greatest interest. The reserve raw material base is iron-chrome-nickel brown iron ores of the Serov deposit after the development of technology for their processing.

The USSR ranks first in the world in iron ore reserves. The Soviet Union contains about 54% of the world's proven iron ore reserves. The main deposits in the USSR are the following.

South and Center of the USSR

The ores of the Krivoy Rog deposit are distinguished by a high iron content and a small amount of harmful impurities: 0.04 - 0.08% S and 0.03 - 0.06% R. The Krivoy Rog basin has very large deposits of so-called quartzites, which contain about 35% iron and approximately the same amount of gangue in the form of silica (SiO 2).

The Kerch deposit is represented mainly by brown iron ores, which contain up to 4.6% manganese, up to 1% phosphorus (sometimes higher) and relatively little iron - up to 39%.

The Tula and Lipetsk deposits are represented by brown iron ores. In the ore of the Tula deposit, the iron content reaches 45%, and in the Lipetsk ore - up to 47%. Tula ore contains more phosphorus (about 0.44%).

The Belgorod iron ore district includes five deposits. Some deposits in this area are rich in magnetite quartzites. There are also rich ores here, in which the iron content reaches 61%.

Kursk Magnetic Anomaly (KMA) is a deposit containing rich hematites (containing 54.8 - 61.4% iron) and poor quartzites. The deposit is very large and promising.

North-West deposits

There are seven iron ore deposits in this area. The largest are Olenegorskoye and Eno-Kovdorskoye, the ores of which serve as the iron ore base of the Cherepovets Metallurgical Plant. The ores of the Olenegorsk deposit are mainly represented by magnetites and hematites. The average iron content in these ores is about 31%. The waste rock of this deposit is the same as in the Krivoy Rog deposit. Features of the chemical composition of the iron ores of the Eno-Kovdor deposit are their high phosphorus content and the increased basicity of the waste rock. The average iron content for this deposit is 30%.

Iron ore deposit of the Caucasus and Transcaucasia

The iron ore base of the Transcaucasian Metallurgical Plant is the Dashkesan deposit. The ores of this deposit contain up to 14% lime (CaO) and up to 1.2% magnesia (MgO). In terms of iron content, they are classified as poor, since its content does not exceed 39%.

Iron ore deposits of the Urals

The largest deposits in this area include Magnitogorskoye (the ore is used by the Magnitogorsk Iron and Steel Works), Tagil-Kushvinskoye (Kushvinsky and Novo-Tagilsky Metallurgical Plants) and Bakalskoye (Chelyabinsk Metallurgical Plant).

The bulk of the magnetic iron ore of the Magnitogorsk deposit consists of two types of ores: magnetite and martite. The magnetites of this deposit are sulfurous. The sulfur content in individual nests reaches 4%, and iron 59%. Martites contain significantly less sulfur (up to 0.16%) with an average iron content of 62% (up to 65%). The gangue of these ores consists of silica, alumina, lime and magnesia. The main waste rock is alumina.

Tagil-Kushva magnetic iron ores (Mountains Blagodat, Vysokaya and Lebyazhya) contain up to 62% iron; in some places its content decreases to 30 - 32%. The gangue of these ores consists of silica and alumina. The ore is sulfurous and phosphorous; in some areas the sulfur content reaches 1.5% and phosphorus 1.2%. In some areas the ore is relatively pure in phosphorus. Goroblagodat ore contains copper. During mining, ore is divided into low-copper ore, containing up to 0.2% copper, and cuprous ore - up to 0.7%. Lumpy enriched ores are used for blast furnace smelting in their raw form, and dusty ores are used after enrichment and agglomeration.

Brown iron ores of the Bakal deposit can be considered pure in sulfur and phosphorus. The average iron content in the ores of this deposit is 48 - 50%.

Iron ores of Siberia and the Far East

The deposits in this area can be divided into several groups:

Mountainous Shoria, where the ores contain 42 - 55% iron, and Khakassia (the ores contain up to 46% iron). These deposits are the raw material base of the Kuznetsk Metallurgical Plant.

Beloretskaya, Inskaya (in Altai), Auzasskaya and Alatau-Altalytskaya groups, the ores of which will become the raw material base of the West Siberian Metallurgical Plant.

The Angaro-Pitskaya and Angaro-Ilimsk groups with the Nizhne-Angarsk, Korshunovsk, Rudnogorsk and other deposits will be the main bases of the new metallurgical plants - Krasnoyarsk and Pribaikalsk.

Garinskaya and Kimpanskaya groups (Far East), Priargunsky district of the Chita region and Aldanskaya group in the Yakut Autonomous Soviet Socialist Republic.

Waste rock from deposits in Siberia and the Far East is presented mainly in the form of calcium oxide (CaO), which does not cause difficulties during blast furnace smelting. Rich ores of this area contain from 50 to 55%, and poor ores 33 to 45% iron.

Deposits of the Kazakh SSR

On a territorial basis, the iron ore resources of the Kazakh SSR are divided into three regions: Central Kazakhstan, Aral and Kustanai. The latter iron ore region is also the base of the Magnitogorsk Iron and Steel Works and the Barnaul Plant in Western Siberia. This area is represented by magnetite ores (45 - 59%) of the Sokolovskoye, Sarbaiskoye, Kacharskoye, Kurzhunkulskoye and other deposits; brown iron ores (37 - 42%) of the Ayatskoye, Lisakovskoye and Kirovskoye deposits.

According to technological types, iron ores are divided into magnetites (19.0%), hematites (1.9%), brown iron ores (77.3%), siderites (0.1%) and hematite quartzites (1.7%), from of which 4.17 million tons do not require enrichment (55.9%).

The most important indicator of the quality of iron ore is its iron content. Therefore, when metallurgically evaluating iron ores, attention is first of all paid to this indicator, as well as to the composition of the waste rock. Waste rock, for which the ratio of the sum of bases CaO + MgO to the sum of acids SiO2 + Al 2 O 3 is equal to or close to unity, is called self-melting.