Characteristic properties of copper. Features of the use of copper in various fields of industry and construction. Copper mining methods

The ancient Greeks called this element khalkos, in Latin it is called cuprum (Cu) or aes, and medieval alchemists called this chemical element just like Mars or Venus. Mankind has long become acquainted with copper due to the fact that in natural conditions it could be found in the form of nuggets, which are often very impressive in size.

The easy reducibility of carbonates and oxides of this element contributed to the fact that, according to many researchers, our ancient ancestors learned to recover from ore before all other metals.

At first, copper rocks were simply heated over an open fire, and then sharply cooled. This led to their cracking, which made it possible to perform metal recovery.

Having mastered such a simple technology, man began to gradually develop it. People learned to blow air into fires with the help of furs and pipes, then they thought of installing walls around the fire. In the end, the first shaft furnace was also constructed.

Numerous archaeological excavations have made it possible to establish a unique fact - the simplest copper products existed already in the 10th millennium BC! And more actively copper began to be mined and used after 8-10 thousand years. Since then, humanity has been using this chemical element, unique in many respects (density, specific gravity, magnetic characteristics, and so on), for its needs.

Copper nuggets are extremely rare these days. Copper is mined from various, among which the following can be distinguished:

bornite (it contains up to 65% of cuprum);
copper luster (aka chalcocite) with a copper content of up to 80%;
copper pyrite (in other words, chalcoperite), containing about 30% of the chemical element of interest to us;
covellite (it contains up to 64% Cu).

Also, cuprum is mined from malachite, cuprite, other oxide ores and almost 20 other minerals containing it in various quantities.

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IN simple form the described element is a pinkish-red metal, characterized by high ductility. Natural cuprum contains two nuclides with a stable structure.

The radius of a positively charged copper ion has the following meanings:

with a coordination index of 6 - up to 0.091 nm;
with an indicator of 2 - up to 0.060 nm.

A neutral atom of an element has a radius of 0.128 nm and an electron affinity of 1.8 eV. With successive ionization, the atom has values from 7.726 to 82.7 eV.

Cuprum is a transition metal, so it has variable oxidation states and a low electronegativity (1.9 units on the Pauling scale). (coefficient) is equal to 394 W / (m * K) at a temperature range from 20 to 100 ° C. The electrical conductivity of copper (specific index) is a maximum of 58, a minimum of 55.5 MSm / m. Only silver is characterized by a higher value, the electrical conductivity of other metals, including aluminum, is lower.

Copper cannot displace hydrogen from acids and water, since it is located to the right of hydrogen in the standard potential row. The described metal is characterized by a face-centered cubic lattice with a value of 0.36150 nm. Copper boils at a temperature of 2657 degrees, melts at a temperature of a little over 1083 degrees, and its density is 8.92 grams / cubic centimeter (for comparison, the density of aluminum is 2.7).

Other mechanical properties of copper and important physical characteristics:

pressure at 1628 ° C - 1 mm Hg. Art .;
thermal expansion (linear) - 0.00000017 units;
tensile strength is reached equal to 22 kgf / mm2;
copper hardness - 35 kgf / mm2 (Brinell scale);
specific gravity - 8.94 g / cm3;
modulus of elasticity - 132000 MN / m2;
elongation (relative) - 60%.

The magnetic properties of copper are somewhat unique. The element is completely diamagnetic, its magnetic atomic susceptibility index is only 0.00000527 units. The magnetic characteristics of copper (however, like all of its physical parameters- weight, density, etc.) determine the demand for an element for the manufacture of electrical products. Approximately the same characteristics are available for aluminum, so they form a "sweet couple" with the described metal, used for the production of conductive parts, wires, cables.

It is almost impossible to change many mechanical parameters of copper (the same magnetic properties, for example), but the ultimate strength of the element in question can be improved by performing work hardening. In this case, it will approximately double (up to 420–450 MN / m2).

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Cuprum in Mendeleev's system is included in the group of noble metals (IB), it is in the fourth period, has a serial number of 29, has a tendency to complex formation. Chemical characteristics copper is no less important than its magnetic, mechanical and physical characteristics, be it its weight, density, or any other value. Therefore, we will talk about them in detail.

The reactivity of cuprum is low. Copper in a dry atmosphere changes insignificantly (one might even say that it hardly changes). But with an increase in humidity and the presence of environment carbon dioxide, a greenish film is usually formed on its surface. It contains CuCO3 and Cu (OH) 2, as well as various sulfurous copper connections... The latter are formed due to the fact that there is almost always a certain amount of hydrogen sulfide and sulfur dioxide in the air. This greenish film is called patina. It protects the metal from destruction.

If copper is heated in air, oxidation of its surface will begin. At temperatures from 375 to 1100 degrees as a result of oxidation, a two-layer scale is formed, and at temperatures up to 375 degrees - copper oxide. At ordinary temperatures, Cu compound with moist chlorine is usually observed (the result of such a reaction is the appearance of chloride).

Copper also interacts with other elements of the halogen group quite easily. In sulfur vapors it lights up, high level it also has an affinity for selenium. On the other hand, Cu does not combine with carbon, nitrogen and hydrogen even at elevated temperatures. Upon contact of copper oxide with sulfuric acid (dilute), sulfate and pure copper are obtained, with hydroiodic and hydrobromic acids - copper iodide and bromide, respectively.

If the oxide is combined with one or another alkali, the result of a chemical reaction will be the appearance of cuprate. But the most famous reducing agents (carbon monoxide, ammonia, methane and others) are able to restore copper to a free state.

Of practical interest is the ability of this metal to react with iron salts (in the form of a solution). In this case, the reduction of iron and the transition of Cu into solution are recorded. This reaction is used to remove the sprayed copper layer from decorative items.

In mono- and bivalent forms, copper is capable of creating complex compounds with a high index of stability. These compounds include ammonia mixtures (they are of interest for industrial enterprises) and double salts.

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The main field of application of aluminum and copper is probably known to everyone. A variety of cables are made of them, including power ones. This is facilitated by the low resistance of aluminum and copper, their special magnetic capabilities. In the windings of electric drives and in transformers (power) are widely used copper wires, which are characterized by the unique purity of copper, which is the initial raw material for their production. If only 0.02 percent of aluminum is added to such purest raw materials, the electrical conductivity of the product will decrease by 8-10 percent.

Cu, which has high density and strength, as well as low weight, lends itself well to mechanical processing. This allows us to produce excellent copper pipes that demonstrate their high performance in gas, heating, and water supply systems. In many European countries, it is copper pipes that are used in the overwhelming majority of cases for the arrangement of internal engineering networks of residential and administrative buildings.

We have said a lot about the electrical conductivity of aluminum and copper. Let's not forget about the excellent thermal conductivity of the latter. This characteristic makes it possible to use copper in the following structures:

in heat pipes;
in coolers of personal computers;
in heating systems and air cooling systems;
in heat exchangers and many other devices that remove heat.

The density and low weight of copper materials and alloys have led to their widespread use in architecture.

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It is clear that the density of copper, its weight and all kinds of chemical and magnetic indicators, by and large, are of little interest to the average person. But many people want to know the healing properties of copper.

The ancient Indians used copper to treat the organs of vision and various ailments of the skin. The ancient Greeks cured ulcers, severe swelling, bruises and bruises with copper plates, as well as more serious diseases (inflammation of the tonsils, congenital and acquired deafness). And in the east, copper red powder, dissolved in water, was used to repair broken bones in the legs and arms.

The medicinal properties of copper were well known to the Russians. Our ancestors used this unique metal to cure cholera, epilepsy, polyarthritis and radiculitis. Currently, copper plates are usually used for treatment, which are applied to special points on the human body. The healing properties of copper with this therapy are manifested in the following:

the protective potential of the human body increases;
infectious diseases are not terrible for those who are treated with copper;
there is a decrease in pain and the removal of inflammation.

Copper is a metal that was one of the first to be mastered by people and was widely used due to its low melting point. This metal is found in nature even more often than iron. The widespread use of copper began immediately after the Stone Age. S.A. Semyonov conducted a lot of studies that showed that the use of tools and tools made of copper gives much more advantages than stone ones.

In ancient times, copper was used not only in its pure form, but also in alloys with tin, calling the resulting metal bronze. Bronze was used to make tools, tools, dishes and jewelry because it was more durable than copper.
Initially, copper was mined not from sulphide, but from malachite ore, because it required much less additional processing. To obtain copper, a mixture of malachite ore and coal was placed in an earthen vessel, the container was placed in a small pit, and then the coal was set on fire. Carbon monoxide released from the burning of coal produced free copper from malachite. Already around the 3rd millennium BC. in Cyprus, mines appeared, engaged in the extraction and smelting of copper.

Why copper was named that way

In Latin, copper sounds like Cuprum, and this name comes from the first mine from the island of Cyprus. Another Latin name for copper is Aes, which means mine.
The word copper is already found in the most ancient literary works, but there it does not have a clear designation. V.I. Abaev suggested calling the metal copper, based on the name of the country of Media: * Mѣd from ir. Mada.
Alchemists originally called copper "Venus", although the name "Mars" can also be found in more ancient treatises.

Physical properties of copper

Copper is a highly ductile metal that has a golden pink color. When interacting with air, copper is rather short time covered with an oxide film that gives it a yellowish-red tint.
Copper is one of the few metals that has a color, because most metals have silver.
Copper has a high thermal conductivity, and in terms of electrical conductivity it ranks second among all metals. In addition, this metal has a high temperature coefficient of resistance: 0.4% / ° C.
There are many alloys with copper: zinc alloy - brass, tin alloy - bronze, nickel alloy - cupronickel, etc.

The use of copper in production

The use of copper in production is quite extensive, because this metal has significant advantages. Most often, copper is used:

In electrical engineering, due to its low resistivity. In electrical engineering, it is used for the manufacture of cables and conductors.
Cooling system for laptop heat pipes - used due to high thermal conductivity.
To create pipes - copper has high strength and is excellent for processing metal products. Copper pipes are excellent for transporting gas and liquids. In some countries, copper is the main material for making pipes.
In jewelry, this metal is widely used to create jewelry, because it easily contacts other precious metals.
Copper is an ideal conductor of electricity and is therefore excellent for induction installations. As a rule, the inductor is made of copper.

The scope of application of copper is quite extensive and is not limited only to the above-described areas. Today, copper is a widespread metal that makes the task of many metallurgical enterprises easier. Copper easily lends itself to this type of heat treatment such as heating of a TVC and soldering of a TVC.

Since the 15th century, the Indians of Ecuador have been smelting copper, containing 99.5%, and creating coins from them. Coin made by Indians was in circulation for the most part South America, including used by the Incas.
In Japan, copper pipes carrying gas are recognized as the most "earthquake resistant".
An adult's body can contain up to 80 mg of copper.
Polish scientists have found that in reservoirs containing copper, carps are especially large.

So we got acquainted with such a versatile and popular metal as copper. The price of copper today reaches up to $ 8,000 per ton.

History of copper

Copper is called one of the first metals that man mastered in antiquity and uses it to this day. Copper mining was affordable because the ore had to be smelted at a relatively low temperature. The first ore from which copper was mined was malachite ore (calorizator). Stone Age in the history of mankind has changed exactly copper, when household items, tools and weapons made of copper became widespread.

Copper is an element of the XI group of the IV period of the periodic system of chemical elements of D.I. Mendeleev, has an atomic number of 29 and an atomic mass of 63.546. The accepted designation is Cu(from Latin Cuprum).

Being in nature

Copper is widely represented in the earth's crust, in sedimentary rocks, in the waters of sea and fresh water bodies, in shales. It is distributed both in the form of compounds and in an independent version.

Physical and chemical properties

Copper is a ductile, so-called transition metal, has a golden pink color. Upon contact with air, an oxide film forms on the surface of the copper, giving the metal a yellowish-red tint. The main copper alloys are known - with zinc (brass), with tin (bronze), with nickel (cupronickel).

Daily copper requirement

The requirement for copper in an adult is 2 mg per day (about 0.035 mg / 1 kg of body weight).

Copper is one of the most important micronutrients for the body, so foods rich in copper should be in everyone's diet. This is:

nuts, cereals,
fish,
cereals (especially and),
dairy products
, berries and

Signs of copper deficiency

Signs of an insufficient amount of copper in the body are: anemia and impaired breathing, loss of appetite, indigestion, nervousness, depression, fatigue, pigmentation disorders of the skin and hair, fragility and hair loss, skin rashes, frequent infections. Internal bleeding is possible.

Signs of excess copper

An overabundance of copper is characterized by insomnia, brain disturbances, epilepsy, and menstrual problems.

Interactions with others

It is assumed that copper and compete with each other in the process of absorption in the digestive tract, so an excess of one of these elements in food can cause a deficiency of another element.

Copper is of great importance in the national economy, its main application is electrical engineering, but the metal is widely used for minting coins, often in works of art. Copper is also used in medicine, architecture, and construction.

Useful properties of copper and its effect on the body

Required to convert the body into hemoglobin. Enables the use of the amino acid tyrosine, allowing it to act as a pigmentation factor for hair and skin. After copper is absorbed by the intestines, it is transported to the liver with the help of albumin. Copper is also involved in the growth and reproduction processes. Takes part in the formation of collagen and elastin and the synthesis of endorphins - hormones of "happiness".

Copper is a malleable, golden-pink metal with a characteristic metallic luster. In the periodic system of D.I.

The Latin name Cuprum comes from the name of the island of Cyprus. It is known that there were copper mines in Cyprus in the 3rd century BC and local craftsmen smelted copper. You can buy copper in the company « ».

According to historians, the acquaintance of society with copper is about nine millennia. The most ancient copper items were found during archaeological excavations in the area of modern Turkey. Archaeologists have discovered small copper beads and plaques for decorating clothes. The finds date back to the turn of the VIII-VII thousand BC. In ancient times, copper was used to make jewelry, expensive dishes and various tools with a thin blade.

The great achievement of the ancient metallurgists can be called the production of an alloy with a copper base - bronze.

Basic properties of copper

1. Physical properties.

In air, copper acquires a bright yellowish-red hue due to the formation of an oxide film. Thin plates are greenish-blue when translucent. In its pure form, copper is quite soft, viscous and easily rolled and stretched. Impurities can increase its hardness.

The high electrical conductivity of copper can be called the main property that determines its preferential use. Copper also has a very high thermal conductivity. Impurities such as iron, phosphorus, tin, antimony and arsenic affect the basic properties and reduce electrical conductivity and thermal conductivity. According to these indicators, copper is second only to silver.

Copper has a high density, melting point and boiling point. Good corrosion resistance is also an important property. For example, at high humidity, iron oxidizes much faster.

Copper lends itself well to processing: it is rolled into a copper sheet and a copper rod, pulled into a copper wire with a thickness brought to thousandths of a millimeter. This metal is diamagnetic, that is, it is magnetized against the direction of the external magnetic field.

Copper is a relatively low-activity metal. Under normal conditions, in dry air, its oxidation does not occur. It reacts easily with halogens, selenium and sulfur. Acids without oxidizing properties do not affect copper. There are no chemical reactions with hydrogen, carbon and nitrogen. In humid air, oxidation occurs with the formation of copper (II) carbonate - the upper layer of platinum.
Copper is amphoteric, that is, it forms cations and anions in the earth's crust. Depending on the conditions, copper compounds exhibit acidic or basic properties.

Methods for obtaining copper

In nature, copper exists in compounds and in the form of nuggets. Compounds are represented by oxides, hydrocarbonates, sulfurous and carbon dioxide complexes, as well as sulfide ores. The most common ores are copper pyrite and copper luster. The copper content in them is 1-2%. 90% of primary copper is mined by pyrometallurgical method and 10% by hydrometallurgical method.

1. The pyrometallurgical method includes the following processes: beneficiation and roasting, matte smelting, blowing in a converter, electrolytic refining.
Copper ores are enriched by flotation and oxidative roasting. The essence of the flotation method is as follows: copper particles suspended in an aqueous medium adhere to the surface of air bubbles and rise to the surface. The method allows you to obtain a copper powder concentrate, which contains 10-35% copper.

Copper ores and concentrates with a significant sulfur content are subject to oxidative roasting. When heated in the presence of oxygen, sulfides are oxidized, and the amount of sulfur is almost halved. Lean concentrates containing 8-25% copper are roasted. Rich concentrates containing 25-35% copper are melted without roasting.

The next stage of the pyrometallurgical method for producing copper is matte smelting. If lump copper ore with a large amount of sulfur is used as a raw material, then smelting is carried out in shaft furnaces. And for the powdery flotation concentrate, reverberatory furnaces are used. Melting takes place at a temperature of 1450 ° C.

In horizontal side-blown converters, the copper matte is blown with compressed air in order to oxidize sulphides and ferrum. Further, the formed oxides are transferred to slag, and sulfur to oxide. Blister copper is formed in the converter, which contains 98.4-99.4% copper, iron, sulfur, as well as trace amounts of nickel, tin, silver and gold.

Blister copper is subject to fire and then electrolytic refining. Impurities are removed with gases and transferred to slag. As a result of fire refining, copper is formed with a purity of up to 99.5%. And after electrolytic refining, the purity is 99.95%.

2. The hydrometallurgical method consists in leaching copper with a weak solution of sulfuric acid, and then separating metallic copper directly from the solution. This method is used for processing poor ores and does not allow the associated extraction of precious metals along with copper.

Application of copper

Thanks to valuable qualities copper and copper alloys are used in the electrical and electrical engineering industry, in radio electronics and instrument making. There are copper alloys with metals such as zinc, tin, aluminum, nickel, titanium, silver, gold. Less commonly used alloys with non-metals: phosphorus, sulfur, oxygen. There are two groups of copper alloys: brass (alloys with zinc) and bronze (alloys with other elements).

Copper is highly environmentally friendly, which allows its use in the construction of residential buildings. For example, a copper roof, due to its anti-corrosion properties, can last more than a hundred years without special maintenance and painting.

Copper in alloys with gold is used in jewelry. This alloy increases the strength of the product, increases the resistance to deformation and abrasion.

Copper compounds are characterized by high biological activity. In plants, copper takes part in the synthesis of chlorophyll. Therefore, she can be seen in the composition mineral fertilizers... Lack of copper in the human body can cause a deterioration in the composition of the blood. It is found in many foods. For example, this metal is found in milk. However, it is important to remember that excess copper compounds can cause poisoning. That is why you cannot cook food in copper dishes. Large amounts of copper can be added to food during boiling. If the dishes inside are covered with a layer of tin, then there is no danger of poisoning.

In medicine, copper is used as an antiseptic and astringent. It is a component of conjunctivitis eye drops and burn solutions.

Copper is a ductile metal of golden-pink color, which in its pure form is found in nature more often than nuggets of gold or silver. But mainly copper is mined from copper ores - natural mineral formations. Most of the copper is found in sulfide ores. In oxidation zones, copper is found in most silicates, carbonates, and oxides. Copper is also found in sedimentary rocks: shale and cuprous sandstones.

More than 200 copper minerals are known to modern science. The industry most often uses metal extracted from sulfates, including:

Chalcocite (79% copper);
Bornite (up to 65%);
Chalcopyrite, or copper pyrite (about 35%).

Copper is also contained in copper-nickel compounds. The most famous of them is cubanite (up to 45% copper). Of the oxidized ores, it is worth noting cuprite (88%), malachite (up to 58%), azurite (up to 56%). Native copper deposits are sometimes found.

Characteristics and types of copper

Copper is one of the first metals to be used by humans. The chemical symbol is Cu (Cuprum). This metal has high thermal conductivity, corrosion resistance, electrical conductivity. Copper melts at low temperatures, excellent solderability, and the metal is easy to cut and process.

Some copper compounds can be toxic to humans. Excessive copper content in water and food can cause liver and gallbladder disease. The quarries left behind after the extraction of copper become sources of toxins. For example, Berkeley Peet Lake, formed in the crater of a former copper mine, is considered the most toxic lake in the world. But, the bactericidal properties of copper are incomparably higher. It has been proven that copper helps fight influenza viruses, destroys staphylococci.

In industry, copper is rarely used in its pure form. Alloys have found greater application:

Brass (copper-zinc alloy);
Bronze (with tin);
Babbits (with lead);
Cupronickel (with nickel);
Dural (with aluminum);
Jewelry alloy (with gold).

Deposits and mining of copper

The largest copper deposit in the world is located in Chile - it is the Esconida quarry. Huge deposits of native copper have been discovered here.

Other major deposits:

Mines on the Kivino Peninsula (USA, Michigan);
Chuquicamata mine in Chile (up to 600 thousand tons per year);
Bolivia's Corocoro Mine;
Mine Gumishevsky (Middle Urals, Russia) - now depleted;
Valley of the Lyovikha River (Middle Ural, Russia);
Massif of gabbro (Italy).

According to the US Geological Survey, Chile owns the largest copper deposits. This is followed by the United States, Russia, Peru and Mexico.

Copper mining methods:

Open;
Hydrometallurgical - when copper is leached from the rock with a weak solution of sulfuric acid;
Pyrometallurgical - consists of several stages (enrichment, roasting, matte smelting, blowing and refining).

Respect for copper ores

Copper ores are non-renewable resources, and therefore their development requires respectful attitude, both in mining methods and in industrial processing.

More and more, the industry is becoming demanding for a constant amount of resources obtained, which leads to their gradual depletion. To do this, it is necessary to carefully control the extraction of copper ores, along with other non-renewable resources, such as oil, natural gas, is more careful and rational in use, both in industrial and domestic consumption.

Application of copper

Copper is one of the most important non-ferrous metals, which has found application in almost all spheres of human life.

Electrical industry (wires, wire);
Mechanical engineering (starter, windows, radiators, coolers, bearings);
Shipbuilding (hull plating);
Construction (pipes, pipelines, roofing and cladding materials, bathtubs, mixers, sinks);
In art (jewelry, statues, coinage);
At home (air conditioners, microwave ovens, coins, food additives, musical instruments).

Interestingly, the Statue of Liberty is made of copper. Its construction required about 80 tons of metal. And in Nepal, copper is considered a sacred metal.