How to mine copper at home. Copper mining technologies and its place in modern industry. The structure of the Russian raw material base of copper

Copper is in the top of the most common elements and is in twenty-sixth place. Usually it is found in the natural environment in the form of separately located pure nuggets, but recently such finds have become less and less common. Accordingly, in the production of metal, such deposits make up only a minimal share.

The main part of copper is mined from rocks in which it is found, often in combination with other metals. There are a large number of copper minerals. But in the metallurgical industry, the most valuable are such types as:

• copper pyrite;
• malachite;
• chalcopyrite;
• azurite

The Russian Federation is one of the five world leaders - the countries in which the mined copper makes up the largest share and brings the most fruitful results. Often, copper, located not too deep relative to the surface of the earth, is mined in an open way. For this purpose, huge quarries or cuts are dug. These open-pit copper mines can be several kilometers wide. In the depths of the same career can stretch for more than one hundred meters. About two-thirds of all copper produced is thus mined. But in cases where copper deposits are deep underground, special facilities are being built that are designed to extract the element under the layers of the earth. They are called mines. On the territory of Russia, copper is mined both by the first and by the second method.

Copper as an element

Copper is the twenty-ninth element of the periodic table, which can be found both in the native derivative and in the composition of natural minerals. These include copper pyrites or chalcopyrite, copper luster or chalcosine, and malachite.

This element is represented in the form of a metal, the shade of which is red. If you break the copper, you can see that inside its color is pink. He is very malleable and malleable. Copper, due to its properties, is an excellent conductor of current and, according to this criterion, is second only to silver, being in second place.

Copper is also a good conductor of heat. Such properties make the element indispensable for the electrical industry - they are used mainly in its pure form. More than fifty percent of all copper mined in the Russian Federation is consumed for the needs of this type of industry.

If we talk about the properties of copper as a chemical element of the periodic table, then it interacts little with other elements. If the copper is exposed to the open air, then its surface becomes greenish, which is explained by the appearance of its basic carbonate, which creates a green film on the upper layer of copper.

Copper salts are widely used in the household. Since they are poisonous, they are used for pest control. They are also actively used as fertilizers and catalysts. Copper alloys such as brass, bronze and cupronickel are also used no less.

As an ore, copper, as a rule, is located in the "company" of several more, or one, metals. Very often it is gold, silver, as well as platinum, nickel or lead and bismuth. A large amount of copper is mined from such a mineral as bornite, the second name of which is motley ore.

The structure of the Russian raw material base of copper

Unlike all countries of the world, forty percent of Russia's raw material base is made up of copper-nickel sulfide deposits. Nineteen percent are pyrite deposits.

And this gives Russia an advantage over other countries, since their main reserves are located in porphyry copper deposits. The Krasnoyarsk ore region is rich in copper and nickel deposits. There are mainly sulfide deposits here.

The main part of all copper deposits in the Russian expanses is located in the Urals and in the Trans-Baikal Territory. In total, more than forty percent of the total copper owned by the country is mined there.

The Orenburg and Chelyabinsk regions have the greatest potential for increasing copper production. The Trans-Baikal Territory is rich in geological and industrial deposits of copper in cuprous sandstones.

The Kemerovo Region, Buryatia, Altai Territory and the North Caucasus are rich in ore from copper pyrite deposits. At the moment, the main share of the mined copper falls on the Udokan deposit. It is currently the largest deposit in the Russian Federation.

In the Far East and the Urals, several new copper deposits were discovered, which belong to the copper-porated type.

Major copper deposits

subsoil user, field	Geological-industrial type	Reserves, kt WO3		Share in balance reserves of the Russian Federation, %	WO3 content in ores, %	Production in 2012, t WO3
		A+B+C1	C2
OJSC MMC Norilsk Nickel
October (Krasnoyarsk region)	Sulfide cupro-nickel	14631	5723	22,3	1,65	351
Talnakh (Krasnoyarsk region)	Sulfide cupro-nickel	7877,2	2728,2	11,6	1,11	80,6
Norilsk I (Krasnoyarsk region)	Sulfide cupro-nickel	773,1	836,1	1,8	0,48	13,9
OJSC Kola MMC
Zhdanovskoye (Murmansk region)	Sulfide cupro-nickel	765,6	227,2	1,1	0,3	12,2
JSC "Gaisky GOK"
Gayskoye (Orenburg region)	copper pyrite	4555,6	478,5	5,5	1,3	62,5
Bashkir Copper LLC
Anniversary (Republic of Bashkortostan)	copper pyrite	1360,2	46	1,5	1,7	36,2
Podolsk (Republic of Bashkortostan)	copper pyrite	1701,3	16,7	1,9	2,11	0
OOO Baikal Mining Company
Udokanskoe (Trans-Baikal Territory)	Cuprous sandstones	14434,6	5519,6	21,8	1,56	0
GDK Baimskaya LLC
Peschanka (Chukotka Autonomous Okrug)	Copper porphyry	2606,2	1124,5	4	0,83	0
OOO GRK Bystrinskoye
Bystrinskoe (Trans-Baikal Territory)	Skarn copper-magnetite	1717,5	355,9	2,3	0,78	0
CJSC Mikheevsky GOK
Mikheevskoe (Chelyabinsk region)	Copper porphyry	1264,3	299,7	1,7	0,44	1,4
ZAO Tominsky GOK
Tominsky (Chelyabinsk region)	Copper porphyry	743,3	793,2	1,7	0,47	0
JSC "Svyatogor"
Volkovskoye (Sverdlovsk region)	Vanadium-iron-copper	1612,2	153,4	1,9	0,64	6,6

Copper Ural

The largest deposits of copper relative to the entire Russian territory are located in the Urals. In order to simplify the extraction of the copper element from those ores in which its presence is very small. This method is called hydrometallurgical. It is also used in cases where it is necessary to extract copper from what is a waste from other metallurgical industries.

The basis of the hydrometallurgical method is the conversion of difficultly soluble compounds of the necessary element into simpler ones, which dissolve more easily. Further, the process of their extraction from the resulting solution takes place. This procedure is carried out in several ways, but the most common of them are:

• solution leaching;
• the use of ion exchange resins;
• electrolysis.

Udokan copper deposit

This deposit is located in the Trans-Baikal Territory on a ridge called "Udokan". This area is seismically dangerous and is located in the permafrost zone. Udokan is the largest copper deposit in Russia. It also occupies an important role in the extraction of this element all over the world, being on the third stage. The ores found in this mine are almost entirely copper and have only a small amount of silver in their composition.

The discovery of the Udokan deposit took place in the last century, or more precisely, in 1949. The first main department of the USSR Ministry of Geology sent a forest expedition to Udokan, which made the first discovery. For the next six years, a detailed study of this field took place and big plans were made for its development. But unexpectedly, after another year, all work was completely frozen.

After another ten years, the field was again actively interested, many different samples were taken, a huge number of other studies were carried out, but then again all work was completely unexpectedly stopped. And only in 2008 the field began to be actively developed. Its development takes place in an open way - copper is mined from a quarry. At the moment, copper deposits in this deposit are large-scale and more than thirty thousand tons of ore are mined from here every year.

Sorskoe copper-molybdenum deposit

This source is located at the intersection of two tectonic zones - northwestern and northeastern, near the Batenevsky ridge. The main minerals that include copper in their composition and are mined here are molybdenite, chalcopyrite, and pyrite.

This deposit was formed due to the fact that high-temperature processes regularly took place in this area. It is divided into several components - Western and Eastern, which in turn are separated from each other by a barren gap.

This field is also being developed by an open method, and its parts - Eastern and Western, have been developed to varying degrees. The second has been mastered almost twice as much as the first.

Ore is enriched here by several processes. This procedure takes place in several ways:

1. in cone-shaped crushers, minerals are crushed four times;
2. wet grinding using specially equipped mills, as well as classifiers made in a spiral shape;
3. flotation, subdivided into two stages - selective and collective;
4. fine-tuning of copper, as well as molybdenum concentrate;
5. dehydration;
6. drying;
7. blending.

The work of the enrichment plant is due to circulating water supply.

Sibay copper-zinc pyrite deposit

This deposit is not only copper, but also zinc and pyrites. It is located near the city of Sibay, which is located in Bashkortostan. The discovery of this deposit took place in 1913, but they began to develop it only two decades later.

From west to east, the Sibay copper-zinc pyrite deposit is limited by faults. Here, ores are mined exclusively by a closed method. At the beginning of the twentieth century, a mine was built on the deposit. Its depth exceeds the depth of four tens of meters.

Later, in 2004, a branch was formed on the site of the Sibayskoye deposit, which is called Uchalinsky GOK.

The main problems of the copper mining industry

Today, one of the main problems of the copper mining industry is its containment. It is due to the fact that the land is gradually becoming poorer, resources are depleted and it is becoming more and more difficult to extract ore.

The dwindling resource base leads to the fact that many enterprises engaged in activities related to the extraction of copper ore are faced with major financial difficulties and not every company manages to go through them by returning to the previous rhythm of work.

But the most serious problem associated with the extraction of copper ore is the strongest environmental pollution. Due to the fact that so-called dumps are formed around the formed quarries, this leads to the fact that after the extraction of ore, heavy metals from them fall into the layers of the earth with every rain, from where they are transported by groundwater currents to rivers and lakes. Recently, there has been talk about turning these embankments into second-rate raw materials that can be used in other production and slightly solve the problem of environmental pollution.

The largest copper mining enterprise in Russia

Recently in the Chelyabinsk region, the largest enterprise in Russia intended for the extraction of copper was launched - this is the Mikheevsky GOK. It is the largest mining project developed on the territory of the state after the collapse of the Soviet Union.

The Mikheevskoye deposit was included in the list of the fifty largest copper deposits in the world. Its main feature is the low content of metal in the mined ore, but its significant reserves. It is planned to extract more than eighteen tons of ore from this deposit annually, and over time to increase the extracted volumes several times.

A huge amount of money was invested in this project, which amounted to twenty-five billion rubles. The opening of this enterprise contributed to the emergence of seven hundred new jobs. The staff of the Mikheevsky GOK includes metallurgists-concentrators, as well as miners. Residents of nearby territories work here. In total, the company's staff numbers about one thousand people.

The management plans to equip the enterprise with 100% water circulation, which will be closed. The equipment located at the enterprise and all its systems will be equipped with the latest technology. Dust collection and dust suppression systems will be installed here, which will facilitate the most difficult work of the Mikheevsky GOK employees.

The most common copper ore on our planet is bornite. But besides it, copper is also mined from other ores, which we will discuss in the framework of this article.

1

By this ore is meant accumulations of minerals in which copper is present in such quantities that are considered suitable for processing it for industrial purposes. The generally accepted indicator of the reasonableness of the development of a deposit is considered to be the situation when copper accumulations in it are at least 0.5–1%.

At the same time, about 90% of the reserves of this metal on earth are found in ores containing not only copper, but also other metals (for example, nickel).

Large-scale copper mining in Russia is carried out in Eastern Siberia, the Urals and the Kola Peninsula. The largest deposits of this metal are present in Chile (according to experts - about 190 million tons). Other countries involved in the development of such ores include the USA, Zambia, Kazakhstan, Poland, Canada, Zaire, Armenia, Congo, Peru, Uzbekistan. In total, the planet's total copper reserves in explored deposits is approximately 680 million tons.

All copper deposits are usually divided into six genetic groups and nine industrial geological types:

• stratiform group (copper shales and sandstones);
• pyrite (native copper, vein and copper-pyrite type);
• hydrothermal (porphyry copper ores);
• magmatic (copper-nickel ore);
• skarn;
• carbonate (iron-copper and carbonatite type).

In our country, the main copper mining is carried out on cuprous shale and sandstone, from copper pyrite, copper-nickel and copper-porphyry ore.

2

In nature, copper is rarely found in its native form. Most often, it "hides" in various compounds. The most famous of them are the following:

3

Other copper minerals are much less common, among which are the following:

4

This metal, whose characteristics (for example, high) led to its wide demand) is obtained from the minerals and ores described by us in three ways - hydrometallurgical, pyrometallurgical and electrolysis. The most common is the pyrometallurgical technology, which uses the mineral chalcopyrite as a feedstock. The general scheme of the pyrometallurgical process includes several operations. The first of these is the enrichment of copper ore by oxidative roasting or flotation.

The flotation method is based on the difference in wettable waste rock and copper containing particles. Due to this, some mineral elements stick (selectively) to the air bubbles and are transported by them to the surface. Such a simple technology makes it possible to obtain a powdered concentrate, in which the copper content varies from 10 to 35 percent.

Oxidative roasting (do not confuse it with) is more often used when the initial raw material contains sulfur in large quantities. In this case, the ore is heated to a temperature of 700-800 degrees, which leads to the oxidation of sulfides and a decrease in the sulfur content by 2 times. After that, melting is performed for matte (an alloy with iron and copper sulfides obtained in reverberatory or shaft furnaces) at a temperature of 1450 degrees.

Copper matte, which is obtained after all these operations, is blown in horizontal converters without supplying additional fuel (chemical reactions provide the heat necessary for the process) with side blowing for the oxidation of iron and sulfides. The resulting sulfur is converted into SO2, and oxides into slag.

As a result, the so-called black copper comes out of the converter, in which the metal content is approximately 91%. Subsequently, it is subjected to cleaning using fire refining (removal of unnecessary impurities) and an acidified solution of vitriol (copper). Such cleaning is called electrolytic, after which the copper content reaches 99.9%.

With the hydrometallurgical method of copper production, it is obtained by leaching the metal with sulfuric acid (a very weak solution) and separating copper and other precious metals from the resulting solution. This technique is recommended for working with low-grade ores.

Copper ore is a compound of minerals in which copper is present in sufficient concentration for its further processing and use for industrial purposes. In production, it is advisable to use enriched ore with a metal content of at least 0.5-1%.

Copper- a plastic element of a golden-pink hue. In the open air, the metal is immediately covered with an oxygen film, which gives it a specific red-yellow color.

Characteristic properties: corrosion resistance, high thermal and electrical conductivity.

At the same time, the element is characterized by high antibacterial properties, destroys influenza viruses and staphylococci.

In the industrial complex, copper is most often used in alloys with other components: nickel, zinc, tin, gold, etc.

Due to its low resistivity, copper is actively used in the electrical field for the manufacture of power cables and wires. Good thermal conductivity allows the use of this metal in cooling radiators and air conditioners.

The following industries cannot do without copper:

• mechanical engineering (window regulators, bearings);
• shipbuilding (plating of hulls and structures);
• construction (pipes, roofing and facing materials, plumbing equipment, etc.).

For the jewelry industry, alloys with gold are relevant, which increase mechanical strength and abrasion resistance.

Experts predict a large-scale use of metal as antibacterial surfaces in medical institutions (railings, doors, handles, handrails, etc.).

Interesting! The famous Statue of Liberty is made of copper. It took about 80 tons of material for its construction. And in Nepal, this metal is considered sacred.

The Statue of Liberty

Groups of copper ores

All copper ores are usually divided into nine industrial-geological types, which, in turn, are divided into six groups according to their origin:

Stratiform group

This group includes copper shales and sandstones. These materials are represented by large deposits. Their characteristic features are: a simple reservoir shape, a uniform distribution of useful components, a flat surface occurrence, which allows the use of open-pit mining methods.

pyrite group

This includes native copper, vein and copper-pyrite compounds. The native metal is most commonly found in the oxidation zones of copper sulfide mines along with other oxidized minerals.

Copper-pyrite metals differ in shapes and sizes. The main mineral in the ore is pyrite, chalcopyrite and sphalerite are also present.

Veined ores are characterized by a veinlet structure with inclusions. Such ores, as a rule, occur in contact with porphyries.

Porphyry copper (hydrothermal)

These deposits, together with copper and molybdenum, contain gold, silver, selenium and other useful elements, the presence of which is much higher than the norm.

Copper Nickel

The deposits are presented in reservoir, lenticular, irregular and vein form. The metal has an interspersed massive texture with cobalt, platinoids, gold, etc.

Skarn ore

Skarn ores are local deposits in limestones and calc-terrigenous rocks. They are characterized by small size and complex morphology. The copper concentration is high, but uneven - up to 3%.

Carbonate

This group includes iron-copper and carbonatite ore. This type of copper has been discovered so far the only deposit in South Africa. This complex mine belongs to the alkaline rock massif.

What ore is copper obtained from?

Interesting! Copper is very rarely found in nature in the form of nuggets. To date, the largest such find is considered to be a nugget found in North America in the United States weighing 420 tons.

There are almost 250 types of copper, but only 20 of them are used in industry. The most common of them:

Khalkozin

Compound of minerals containing sulfur (20%) and copper (80%). It is called "copper sheen" because of its characteristic metallic sheen. The ore has a dense or granular structure of black or gray tint.

Chalcopyrite

The metal is of hydrothermal origin, found in skarns and greisens. Most often it is included in the composition of polymetallic ore together with galena and sphalerite.

bornite

A naturally occurring mineral of the sulfide class, one of the main elements of copper ores. It has a characteristic bluish-purple tint. Contains copper (63.33%), iron (11.12%), sulfur (25.55%) and silver impurities. It occurs in the form of dense fine-grained masses.

Methods for extracting copper ore

Depending on the depth of the mine, open and closed methods of metal mining are used.

In closed (underground) development, mines are built with a length of several kilometers. The mines are equipped with elevators to move workers and equipment, as well as to transport the mineral to the surface.

Under the ground, the rock is subject to crushing with special drilling equipment with spikes. Then, with the help of buckets, the ore is taken and loaded.

The open method is relevant when the deposits are at a depth of up to 400-500 meters. First, the upper layer of waste rock is removed, after which the copper ore is removed. To make it easier to get hard rocks, it is first destroyed by explosive devices.

Open pit mining of copper ore

There are two main methods of copper production:

• pyrometallurgical;
• hydrometallurgical.

The first method involves fire refining of the metal and allows you to process any raw material with the extraction of all useful elements. Using this technology, it is possible to obtain copper even from poor rock, in which the metal content is below 0.5%. The second method is used, as a rule, only for the processing of oxidized or native ore with poor copper content.

Mining of copper ores in the world

Copper mines are not concentrated in certain geographical areas, but are found in different countries. In America, in the states of Nevada and Arizona, chalcosine deposits are being developed. Copper oxide deposits, cuprite, are common in Cuba. Copper chloride is mined in Peru.

There are almost no sources of enriched ores left in the world, copper has been mined for several hundred years, so all the rich mines have long been developed. In industry, low-grade minerals (up to 0.5% copper) have to be used.

Interesting! In terms of world production, copper is in third place after iron and aluminum.

Leading countries in terms of reserves and production of copper ore

The list of countries rich in copper ores includes: Chile, America, China, Kazakhstan, Poland, Indonesia, Zambia. The share of the Russian Federation in the world ore production is 9% (this is the third place after Chile and the USA). In terms of mineral reserves, Chile is the leader, in which 33% of the world's copper is located.

The largest mines are:

• Chuquicamata mine (Chile). Developments have been going on for more than 100 years, during this period 26 million tons of metal have been developed;

• Escondida mine (Chile). Mining has been carried out since 1990;

• Grasberg mine (Indonesia).

Recently, large mines have been discovered in Peru (Antamina), Brazil (Salobu), Kazakhstan (Nurkazgan).

Experts say that the volume of economically viable copper is more than 400 million tons. around the world.

Extraction of copper ore in Russia

The structure of the raw material base of copper in Russia is significantly different from the world market. The main share in it falls on sulfide copper-nickel (40%) and pyrite (19%) mines. While in other countries porphyry copper deposits and cuprous sandstones predominate.

Deposits of copper ores in Russia

When answering the question of where copper ores are mined in Russia, the Taimyr Autonomous Okrug should be singled out first. More than 60% of all copper ore deposits in Russia are concentrated in the Oktyabrsky, Tapakhninsky and Norilsk deposits. About one third of the mineral is mined in the Ural copper ore region.

In the Chita region, a large Udokan mine has been discovered, which has not yet been developed due to an undeveloped transport infrastructure. According to expert data, the exploited fields in the Russian Federation will last no more than 30 years.

In small concentrations may be present:

• nickel;
• gold;
• platinum;
• silver.

Deposits all over the world have approximately the same set of chemical elements in the composition of the ore, differing only in their percentage. To obtain pure metal, various industrial methods are used. Almost 90% of metallurgical enterprises use the same method of producing pure copper - pyrometallurgical.

The scheme of this process also makes it possible to obtain metal from secondary raw materials, which is a significant plus for industry. Since the deposits belong to the group of non-renewable deposits, the reserves decrease every year, the ores become poorer, and their extraction and production becomes expensive. This ultimately affects the price of the metal on the international market. In addition to the pyrometallurgical method, there are other ways:

• hydrometallurgical;
• fire refining method.

Stages of pyrometallurgical production of copper

The industrial production of copper using the pyrometallurgical method has advantages over other methods:

• the technology provides high productivity - with its help it is possible to obtain metal from rocks in which the copper content is even lower than 0.5%;
• allows you to efficiently process secondary raw materials;
• a high degree of mechanization and automation of all stages has been achieved;
• when using it, emissions of harmful substances into the atmosphere are significantly reduced;
• method is economical and efficient.

Enrichment

Ore beneficiation scheme

At the first stage of production, it is necessary to prepare the ore, which is delivered to the processing plants directly from the quarry or mine. Often there are large pieces of rock that must first be crushed.

This happens in huge crushing units. After crushing, a homogeneous mass is obtained, with a fraction of up to 150 mm. Pre-enrichment technology:

• raw materials are poured into a large container and filled with water;
• oxygen is then added under pressure to form a foam;
• metal particles stick to the bubbles and rise to the top, and the waste rock settles at the bottom;
• further, the copper concentrate is sent for roasting.

Burning

This stage aims to reduce the sulfur content as much as possible. The ore mass is placed in a furnace, where the temperature is set to 700–800 o C. As a result of thermal exposure, the sulfur content is halved. Sulfur oxidizes and evaporates, and part of the impurities (iron and other metals) passes into an easily slag state, which will facilitate further smelting.

This stage can be omitted if the rock is rich and contains 25–35% copper after enrichment, it is used only for poor ores.

Melting on matte

The matte smelting technology makes it possible to obtain blister copper, which differs in grades: from MCh1 - the purest to MCh6 (contains up to 96% pure metal). During the smelting process, the raw material is immersed in a special furnace in which the temperature rises to 1450 o C.

After melting the mass, it is blown with compressed oxygen in converters. They have a horizontal view, and blowing is carried out through a side hole. As a result of blowing, iron and sulfur sulfides are oxidized and converted into slag. The heat in the converter is formed due to the flow of the hot mass, it does not heat up additionally. The temperature is 1300 o C.

At the output of the converter, a draft composition is obtained, which contains up to 0.04% iron and 0.1% sulfur, as well as up to 0.5% other metals:

• tin;
• antimony;
• gold;
• nickel;
• silver.

Such rough metal is cast into ingots weighing up to 1200 kg. This is the so-called anode copper. Many manufacturers stop at this stage and sell such ingots. But since the production of copper is often accompanied by the extraction of precious metals contained in the ore, the processing plants use the technology of refining the crude alloy. At the same time, other metals are separated and preserved.

Refining with cathode copper

The technology for obtaining refined copper is quite simple. Its principle is even used to clean copper coins from oxides at home. The production scheme looks like this:

• a rough ingot is placed in a bath with an electrolyte;
• as an electrolyte, a solution with the following content is used:
  • copper sulfate - up to 200 g / l;
  • sulfuric acid - 135–200 g/l;
  • colloidal additives (thiourea, wood glue) - up to 60 g / l;
  • water.
• electrolyte temperature should be up to 55 ° C;
• cathode copper plates are placed in the bath - thin sheets of pure metal;
• electricity is connected. At this time, the electrochemical dissolution of the metal occurs. Copper particles concentrate on the cathode plate, while other inclusions settle to the bottom and are called sludge.

In order for the process of obtaining refined copper to proceed faster, anode ingots should be no more than 360 kg.

The entire electrolysis process takes 20–28 days. During this period, cathode copper is removed up to 3–4 times. The weight of the plates is obtained up to 150 kg.

How it's done: copper mining

During the refining process, dendrites can form on the copper cathode - growths that shorten the distance to the anode. As a result, the speed and efficiency of the reaction is reduced. Therefore, when dendrites occur, they are immediately removed.

Technology of hydrometallurgical production of copper

This method is not widely used, because, in this case, the precious metals contained in copper ore can be lost.

Its use is justified when the rock is poor - it contains less than 0.3% red metal.

How to get copper by hydrometallurgical method?

First, the rock is crushed to a fine fraction. Then it is placed in an alkaline composition. Most often, sulfuric acid or ammonia solutions are used. During the reaction, copper is displaced by iron.

Cementation of copper with iron

The solutions of copper salts remaining after leaching undergo further processing - cementation:

• iron wire, sheets or other scraps are placed in the solution;
• during a chemical reaction, iron displaces copper;
• as a result, the metal is released in the form of a fine powder, in which the copper content reaches 70%. Further purification takes place by electrolysis using a cathode plate.

Technology of fire refining of blister copper

This method of obtaining pure copper is used when the raw material is copper scrap.

The process takes place in special reverberatory furnaces, which are fired with coal or oil. The melted mass fills the bath, into which air is blown through iron pipes:

• pipe diameter - up to 19 mm;
• air pressure - up to 2.5 atm;
• furnace capacity - up to 250 kg.

In the process of refining, copper raw materials are oxidized, sulfur burns out, then metals. Oxides do not dissolve in liquid copper, but float to the surface. To remove them, quartz is used, which is placed in the bath before the refining process begins and is placed along the walls.

If nickel, arsenic or antimony is present in the scrap metal, then the technology becomes more complicated. The percentage of nickel in refined copper can only be reduced to 0.35%. But if other components (arsenic and antimony) are present, then nickel "mica" is formed, which dissolves in copper, and it cannot be removed.

Video: Copper ores of the Urals

Copper mining is closely related to the technology of extracting metal from ore and is carried out in cost-effective ways, taking into account the specifics of the deposit.

Technology for the production of copper products.

Mineral base for metal extraction

The raw materials for the extraction of copper ore are natural formations of minerals, in which the metal component is contained in an amount necessary for economically profitable industrial development.

Raw materials for the extraction of copper ore.

Ore deposits are represented by silicate, carbonate, sulfate compounds, oxides formed in the oxidation zone.

Among the explored minerals for industrial development are:

• chalcopyrite;
• chalcosine;
• bornite;
• cuprite;
• native copper;
• brochantitis;
• azurite;
• cubanite;
• malachite;
• chrysotile.

In ore, the metal concentration is 0.3–5%, and in minerals, the concentration index is 22–100% (native metal). Copper deposits are in a genetic relationship with other valuable components that are mined as additional chemical elements to the main process.

Associated components include:

• platanoids;
• silver;
• gold;
• tellurium;
• gallium;
• molybdenum;
• bismuth;
• nickel;
• titanium;
• zinc.

Ore for extracting copper contains arsenic, antimony, less often mercury. Depending on the type of associated chemical elements, types of deposits are distinguished, among which the main ones are:

• copper-nickel;
• copper pyrite;
• copper sandstones and shales;
• porphyry copper.

Skarn deposits of metal and quartz-sulfide formations are of subordinate importance. In the future, ferromanganese nodules located in the bottom sediments of the World Ocean are considered as raw materials for the industrial production of metal.

Mining methods

How is copper mined in ore deposits? The low concentration of metal in the rock provides for the processing of a large amount of material. To obtain a unit mass of metal, it is required to process 200 units of ore.

Copper, which is mainly mined in an open pit, is located at a depth of up to 1000 m. The depth of open pit mines reaches 150–300 m, and in some cases up to 600 m. Deposits located at a depth of up to 1000 m are mined underground.

Processing of ore in search of copper.

Certain standards regulate the expediency of deepening developments in order to extract ore raw materials. This is due to mining technology, additional costs and reduced equipment productivity, which increase the cost of raw materials.

Therefore, the open method is widely used in the metallurgical industry, which is characterized by insignificant losses during development. Although there are also disadvantages associated with the storage of waste rock.

For example, in 2013, a landslide occurred at the Kennecott Utah Copper Bingham Canyon Mine in the United States. The depth of the Bingham Canyon quarry is about 1 km, and the diameter is about 4 km. Ore has been mined here for 150 years.

Delivery of raw materials to the place of processing was carried out by vehicles with a carrying capacity of 231 tons. The miners were warned about the dangerous phenomenon and were ready for the development of events. The quarry wall moved at a speed of several inches per day, and the attempts made to strengthen it did not give the desired result.

The conditions for the extraction of raw materials require the use of sequential development technology using:

• self-propelled equipment;
• conducting work during the extraction of raw materials;
• bookmarks with special materials of the mined-out space for the purpose of safety of further development.

Each technological process provides for a reduction in losses during the development of deposits, an improvement in the performance of ore output.

When extracting ore in layers, the full use of reserves is ensured. In the conditions of deep quarries, a cyclic-flow technology is used, taking into account the peculiarities of the ore occurrence.

Metal extraction technology

To separate the rock that does not contain a valuable component, the flotation method is used. Only a small amount of raw materials containing copper in high concentrations is subjected to direct smelting. Metal smelting involves a complex process, including the following operations:

• burning;
• fuse;
• converting;
• fire and electrolytic refining.

Melting of raw materials.

During the roasting of raw materials, the sulfides and impurities contained in it turn into oxides (pyrite turns into iron oxide). The gases released during roasting contain sulfur oxide and are used to produce acid.

Metal oxides, formed as a result of the influence of the temperature gradient on the rock, are separated in the form of slag during firing. The liquid product obtained by remelting is converted.

Valuable components are extracted from blister copper and harmful impurities are removed by fire refining and other metals by saturating the liquid mixture with oxygen, followed by pouring into molds. The castings are used as an anode for the electrolytic copper refining process.

The raw material, which contains copper and nickel, is enriched according to the selective flotation scheme in order to obtain a metal concentrate. Iron-copper ores are subjected to magnetic separation.

Ores of cuprous sandstones and shales, vein rocks and native metal are processed to extract copper concentrate. Enrichment is carried out by the gravitational method.

The flotation method is used for mixed and oxidized ores, but the chemical method and bacterial leaching are more commonly used.

Enrichment of ore with a low content of copper can be carried out by a hydrometallurgical method, consisting in the leaching of copper with sulfuric acid. From the solution obtained as a result of the process, copper and related metals, including precious ones, are isolated.