Copper in the compounds has. Features of the use of copper in various fields of industry and construction. Areas of use of copper

Solid metal copper people learned to melt even before our era. The name of the element according to the periodic table is Cuprum, in honor of the first mass production of copper. It was on the island of Cyprus in the third millennium BC. ore began to be mined. Metal has proven to be a good weapon and beautiful, shiny material for the manufacture of dishes and other appliances.

copper melting process

Making items required a lot of effort in the absence of technology. In the first steps of the development of civilization and the search for new metals, people learned how to mine and smelt copper ore. The ore was obtained in the malachite, and not in the sulfide state. Obtaining free copper at the output, from which parts can be made, required firing. To exclude oxides, metal with charcoal was placed in a clay vessel. The metal was set on fire in a specially prepared pit, the carbon monoxide formed in the process contributed to the process of the appearance of free copper.

For accurate calculations, the graph of copper melting was used. At that time, an accurate calculation of the time and approximate temperature at which copper is smelted was made.

Copper and its alloys

The metal has a reddish-yellow hue due to oxide film, which is formed during the first interaction of the metal with oxygen. The film gives a noble appearance and has anti-corrosion properties.

Now there are several ways to extract metal. Common are copper pyrites and glitter, which occur as sulfide ores. Each of the technologies for obtaining copper requires a special approach and following the process.

Mining in natural conditions occurs in the form of a search for copper slates and nuggets. Volumetric deposits in the form of sedimentary rocks are located in Chile, and copper sandstones and shales are located on the territory of Kazakhstan. The use of metal is due to the low melting point. Almost all metals melt by destroying the crystal lattice.

Basic melting order and properties:

• at temperature thresholds from 20 to 100°, the material completely retains its properties and appearance, the top oxide layer remains in place;
• the crystal lattice breaks up at around 1082°, the physical state becomes liquid, and the color is white. The temperature level lingers for a while and then continues to rise;
• the boiling point of copper begins at around 2595 °, carbon is released, a characteristic seething occurs;
• when the heat source is turned off, the temperature decreases and the transition to the solid stage takes place.

Copper smelting is possible at home, subject to certain conditions. The stages and complexity of the task depend on the choice of equipment.

Physical Properties

The main characteristics of the metal:

• in its pure form, the density of the metal is 8.93 g/cm3;
• good electrical conductivity with an indicator of 55.5S, at a temperature of about 20⁰;
• heat transfer 390 J/kg;
• boiling occurs at around 2600 °, after which the release of carbon begins;
• electrical resistivity in the average temperature range - 1.78×10 Ohm/m.

The main areas of exploitation of copper is electrical purposes. High heat transfer and ductility make it suitable for various applications. Alloys of copper with nickel, brass, bronze, make the cost more acceptable and improve performance.

In nature, it is not homogeneous in composition, since it contains a number of crystalline elements that form a stable structure with it, the so-called solutions, which can be divided into three groups:

1. solid solutions. They are formed if the composition contains impurities of iron, zinc, antimony, tin, nickel and many other substances. Such occurrences significantly reduce its electrical and thermal conductivity. They complicate the hot type of pressure treatment.
2. Impurities dissolving in a copper lattice. These include bismuth, lead and other components. They do not impair the quality of electrical conductivity, but make it difficult to process under pressure.
3. Impurities that form brittle chemical compounds. This includes oxygen and sulfur, as well as other elements. They worsen the strength qualities, including reducing the electrical conductivity.

The mass of copper with impurities is much greater than in its pure form. In addition, the elements of impurities significantly affect the final characteristics of the finished product. Therefore, their total composition, including quantitative, should be separately regulated at the production stage. Let us consider in more detail the influence of each element on the characteristics of final copper products.

1. Oxygen. One of the most undesirable elements for any material, not just copper. With its growth, quality such as ductility and resistance to corrosion processes deteriorates. Its content should not exceed 0.008%. During heat treatment, as a result of oxidation processes, the quantitative content of this element decreases.
2. Nickel. Forms a stable solution and significantly reduces conductivity.
3. Sulfur or selenium. Both components have the same effect on quality finished products. A high concentration of such occurrences reduces the plastic properties of copper products. The content of such components should not exceed 0.001% of total weight.
4. Bismuth. negatively affects the mechanical and technological characteristics finished products. The maximum content should not exceed 0.001%.
5. Arsenic. It does not change properties, but forms a stable solution, is a kind of protector from the harmful effects of other elements, such as oxygen, antimony or bismuth.

1. Manganese. It is able to completely dissolve in copper at almost room temperature. Affects the conductivity of the current.
2. Antimony. The component will dissolve best of all in copper, causing minimal harm to it. Its content should not exceed 0.05% by weight of copper.
3. Tin. Forms a stable solution with copper and enhances its heat conduction properties.
4. Zinc. Its content is always minimal, so it does not have such a detrimental effect.

Phosphorus. The main copper deoxidizer, the maximum content of which at a temperature of 714°C is 1.7%.

An alloy based on copper with the addition of zinc is called brass. In some situations, tin is added in smaller proportions. James Emerson in 1781 decided to patent the combination. The zinc content in the alloy can vary from 5 to 45%. Brass is distinguished depending on the purpose and specification:

• simple, consisting of two components - copper and zinc. The marking of such alloys is indicated by the letter "L", which directly means the copper content in the alloy as a percentage;
• multi-component brasses - contain many other metals, depending on the intended use. Such alloys increase the operational properties of products, they are also denoted by the letter "L", but with the addition of numbers.

The physical properties of brass are relatively high, corrosion resistance is average. Most alloys are not critical to low temperatures; it is possible to operate the metal in various conditions.
Brass production technology interacts with the processes of the copper and zinc industries, processing of secondary raw materials. Effective way melting is the use of an induction type electric furnace with a magnetic outlet and temperature control. After obtaining a homogeneous mass, it is poured into molds and subjected to deformation processes.

The use of the material in various industries increases its demand every year. The alloy is used in court construction and the production of ammunition, various bushings, adapters, bolts, nuts and plumbing materials.

Non-ferrous metal for the manufacture of products of various types began to be used from ancient times. This fact is confirmed by the materials found during archaeological excavations. The composition of bronze was originally rich in tin.

The industry produces a different number of varieties of bronze. An experienced craftsman is able to determine its purpose by the color of the metal. However, not everyone can determine the exact brand of bronze; marking is used for this. Methods for the production of bronze are divided into foundry, when melting and casting occurs, and deformable.

The composition of the metal depends on the intended use. The main indicator is the presence of beryllium. The increased concentration of the element in the alloy, subjected to the quenching procedure, can compete with high-strength steels. The presence of tin in the composition takes away the flexibility and ductility of the metal.

The production of bronze alloys has changed since ancient times by actually introducing modern equipment. The technology using charcoal as a flux is still used today. Sequence of obtaining bronze:

• the furnace is heated to the required temperature, after which the crucible is installed in it;
• after melting, the metal may oxidize; to avoid this, flux is added as charcoal;
• phosphoric copper serves as an acid catalyst, the addition occurs after the alloy is completely heated.

smelting bronze

Antique bronzes are subject to natural processes - patination. A greenish color with a white tint appears due to the formation of a film that envelops the product. Artificial patination methods include methods using sulfur and parallel heating to a certain temperature.

Melting point of copper

The material melts at a certain temperature, which depends on the presence and amount of alloys in the composition.

In most cases, the process takes place at a temperature of 1085°. The presence of tin in the alloy gives a run, the melting of copper can begin at 950 °. Zinc in the composition also lowers the lower limit to 900°.

For accurate time calculations, you need a graph of the melting of copper. On an ordinary piece of paper, a graph is used, where time is marked horizontally, and degrees are marked vertically. The graph should indicate at what points the temperature is maintained during heating for the complete crystallization process.

Melting copper at home

At home, copper alloys can be melted in several ways. When using any of the methods, you will need related materials:

• crucible - dishes made of hardened copper or other refractory metal;
• charcoal, needed as a flux;
• metal hook;
• shape of the future product.

The easiest option for melting is the muffle furnace. Pieces of material fall into the container. After setting the melting temperature, the process can be observed through a special window. The installed door allows you to remove the oxide film formed in the process, for this you need a pre-prepared metal hook.

The second way to melt at home is to use a torch or cutter. Propane - an oxygen flame is perfect for working with zinc or tin. Pieces of materials for the future alloy are placed in a crucible and heated by the master with arbitrary movements. The maximum melting point of copper can be reached when interacting with a blue flame.

Melting copper at home involves working at elevated temperatures. Safety is a priority. Before any procedure, you should wear protective fire-resistant gloves and tight clothing that completely covers the body.

Copper Density Value

Density is the ratio of mass to volume. It is expressed in kilograms per cubic meter of the total volume. Due to the heterogeneity of the composition, the density value may vary depending on the percentage of impurities. Since there are different brands of rolled copper with different content of components, their density will also be different. The density of copper can be found in specialized technical tables, which is equal to 8.93x10 3 kg / m 3. This is a reference value. These tables show specific gravity copper, which is equal to 8.93 g / cm 3. Not all metals are characterized by such a coincidence of density values ​​and its weight indicators.

It is no secret that the final mass of the manufactured product directly depends on the density. However, for calculations it is much more correct to use specific gravity. This indicator is very important for the production of products from copper or any other metals, but applies more to alloys. It is expressed as the ratio of the mass of copper to the volume of the entire alloy.

Specific Gravity Calculation

Currently, scientists have developed a huge number of methods to help find the characteristics of the specific gravity of copper, which allow even without resorting to specialized tables to calculate this important indicator. Knowing it, you can easily choose necessary materials, thanks to which, in the end, you can get the desired part with the required parameters. This is done at the preparation stage, when it is planned to create the necessary part from copper or its alloys.

As mentioned above, the specific gravity of copper can be peeped in a specialized reference book, but if this is not at hand, then it can be calculated using the following formula: we divide the weight by volume and get the value we need. In general terms, this ratio can be expressed as the total weight value to the total value of the volume of the entire product.

Do not confuse it with the concept of density, since it characterizes the metal in a different way, although it has the same values ​​​​of the indicators.

Consider how the specific gravity can be calculated if the mass and volume of the copper product are known.

For example, we have a clean copper sheet 5 mm thick, 2 m wide and 1 m long. First, let's calculate its volume: 5 mm * 1000 mm (1 m = 1000 mm) * 2000 mm, which is 10,000,000 mm 3 or 10,000 cm 3. For the convenience of calculations, we will assume that the mass of the sheet is 89 kg 300 grams or 89300 grams. We divide the calculated result by the volume and get 8.93 g / cm 3. Knowing this indicator, we can always easily calculate the weight content in copper of a particular alloy. This is convenient, for example, for metal processing.

Specific Gravity Units

Different measurement systems use different units to indicate the specific gravity of copper:

1. The CGS or centimeter-gram-second system uses dyne/cm3.
2. The International SI uses units of N/m 3 .
3. In the MKSS system or meter-kilogram-second-candle, kg / m 3 is used.

The first two indicators are equal to each other, and the third, when converted, is 0.102 kg / m 3.

Weight calculation using specific gravity values

Let's not go far and use the example described above. Calculate the total copper content in 25 sheets. Let's change the condition and assume that the sheets are made of a copper alloy. Thus, we take the specific gravity of copper from the table and it is equal to 8.93 g / cm 3. The sheet thickness is 5 mm, the area (1000 mm * 2000 mm) is 2,000,000 mm, respectively, the volume will be 10,000,000 mm 3 or 10,000 cm 3. Now we multiply the specific gravity by the volume and we get 89 kg and 300 gr. We calculated the total amount of copper contained in these sheets without taking into account the weight of the impurities themselves, which means that the total weight value may be greater.

Now we multiply the calculated result by 25 sheets and get 2,235 kg. Such calculations are appropriate to use when processing copper parts, as they allow you to find out how much copper is contained in the original objects. Similarly, copper bars can be calculated. The cross-sectional area of ​​the wire is multiplied by its length, where we get the volume of the bar, and then by analogy with the above example.

How density is determined

The density of copper, like the density of any other substance, is a reference value. It is expressed as a ratio of mass to volume. It is very difficult to calculate this indicator on your own, since it is impossible to check the composition without special devices.

Copper Density Calculation Example

The indicator is expressed in kilograms per cubic meter or in grams per cubic centimeter. Density is more useful for manufacturers who, based on available data, can compose a particular part with the required properties and characteristics.

Areas of use of copper

Due to its physical and mechanical properties, it is widely used in various industries. Most often it can be found in the electrical field as an integral part of electric wire. It is equally popular in the production of heating and cooling systems, electronics and heat exchange systems.

In the construction industry, it is used primarily to create various kinds of structures, which are obtained much less in mass than from any other similar materials. Often it is used for roofing, as such products are lightweight and ductile. Such material is easily processed and allows you to change the profile geometry, which is very convenient.

As mentioned above, it finds its main application in the manufacture of electrical and other conductive cables, where it is used for the manufacture of cores of wires and cables. Possessing good electrical conductivity, it gives sufficient resistance to current electrons.

Copper alloys are also widely used, for example, an alloy of copper and gold increases the strength of the latter at times.

Salt deposits never form on the walls of copper bars. This quality is useful for transporting liquids and vapors.

Based on copper oxides, superconductors are obtained, and in its pure form it is used to manufacture galvanic power supplies.

It is part of bronze, which is resistant to aggressive environments, like sea water. Therefore, it is often used in navigation. Also, bronze products can be seen on the facades of houses, as an element of decor, since such an alloy is easily processed, as it is very plastic.

Synonyms: Thin mixtures of native copper and cuprite were called cuprocuprite (Vernadsky, 1910). Whitneyite (Gent, 1859) and Darwinite (Forbes, 1860) are arsenic copper that forms mixtures with algodonite.

origin of name

The Latin name for copper cuprum comes from the name of the island of Cyprus, from where copper was imported in ancient times. The origin of the Russian name is unclear.

The English name for the mineral Copper is Copper

• Chemical composition
• Varieties
• Form of being in nature
• Physical Properties
• Chemical properties. Other properties
• diagnostic signs. Satellites.
• Origin of the mineral
• Place of Birth
• Practical use
• Buy

Formula

Chemical composition

It sometimes contains admixtures of Fe, Ag, Pb, Au, Hg, Bi, Sb, V, Ge 3 (silver copper with 3-4% Ag, iron-2.5% Fe and golden-2-3% Au). Impurities are observed more often in primary native copper; recycled copper is usually purer. The composition of native copper from the Shamlugh deposit (Armenia): Cu - 97.20 -97.46%, Fe - 0.25%; in copper from the Altai deposits, 98.3% Cu and more were determined.

Crystallographic characteristic

Syngony. Cubic.

Class. Hexoctahedral.

Crystal structure

The crystal structure is characterized by a face-centered lattice; copper atoms are located at the corners and in the centers of the faces of the elementary cube. This is a formal expression of the fact that in the structure of copper there is a closest packing (the so-called cubic closest packing) of metal atoms with a radius of 1.27 A and a distance between the nearest atoms of 2.54 A while fulfilling a space of 74.05%. Each Cu atom is surrounded by 12 similar ones (coordination number 12), located around it along the vertices of the so-called Archimedean cuboctahedron.

Main forms:a (100), d (110), o (111), l (530), e (210), h (410).

Form of being in nature

Crystal Shape. The shape of the crystals is cubic, tetrahexahedral, dodecahedral, less often - octahedral (possibly, pseudomorphs after cuprite). The edges are often rough, with depressions or elevations. Simple crystals are rare.

Doubles. Intergrowth twins along (111) are common, sometimes polysynthetic, often lamellar in the axis twin direction or elongated plane twins parallel to the diagonal. Usually crystals (simple and twins) are unevenly developed: elongated, shortened or deformed. Dendritic forms are characteristic, which are uniform intergrowths of many crystals (uniformly deformed or regular) in any one direction. These are, for example, crystals twinning along (111) elongated along the 2nd order symmetry axis and fused parallel to the faces of a rhombic dodecahedron) or intergrowths of regular twin crystals branching along the edges and diagonals of octahedral faces, as well as parallel intergrowths of crystals elongated in the direction axes of the 4th order. In continuous precipitates of native copper during etching, signs of collective crystallization are found with the development of large grains due to smaller, irregularly shaped zonal grains.

Aggregates. Distorted crystals, in single irregular grains, dendritic intergrowths, filamentous, wiry, mossy formations, thin plates, concretions, powdery accumulations and continuous masses weighing up to several hundred tons.

Physical Properties

Optical

The color in the fresh fracture is light pink, quickly changing to copper red, then to brown; often with a yellow or variegated tint.

The line is copper-red, shiny.

Shiny metallic.

Transparency. Opaque. In the thinnest plates, it shines through in green.

Refractive indices

Ng = , Nm = and Np =

Mechanical

Hardness 2.5-3.

Density 8.4-8.9

Cleavage is not observed.

Fracture splintery, hooked.

Chemical properties

Easily soluble in dilute HNO 3 and in aqua regia, in H 2 SO 4 - when heated, in HCl - with difficulty. It dissolves in an aqueous solution of ammonia, turning it blue. In polished sections it can be etched with all major reagents. Internal structure easily detected with NH 4 OH + H 2 O 2 or Hcl + CrO 3 (50% solution).

Other properties

Very malleable and ductile. The electrical conductivity is very high; significantly reduced by impurities.

Behavior on heating. Pure copper melts at 1083°. The thermal conductivity is somewhat less than that of silver.

Artificial production of the mineral.

It can be easily obtained from melts or by electrolysis from solutions of copper salts.

Diagnostic signs

Similar minerals

Recognized by the red color of the fresh surface, shiny line, medium hardness and malleability, usually covered with greenish, black, blue deposits of oxidized copper minerals. Under a microscope in reflected light, it is easily determined by color and reflectivity.

Associated minerals. Cuprous gold, chalcocite, calcite, diopside, apatite, sphene, magnetite, malachite, barite, quartz, chalcopyrite.

Origin and location

Hydrothermal. Accumulates in placers. Nuggets weighing up to 450 tons are described as unique phenomena.

Native copper is formed under reducing conditions during various geological processes; a significant part of it is released from hydrothermal solutions. In the form of microscopic segregations, it is observed in many, mainly mafic, igneous rocks exposed to hydrothermal solutions, for example, in serpentinized peridotites, dunites and serpentinites. In this case, the appearance of native copper is possibly associated with the decomposition of previously formed copper sulfides, for example, cubanite (Urals, Transcaucasia). A similar origin can be attributed to native copper in amphibolized basic rocks of the Serov region. Sverdlovsk region. In the Karabash cuprous gold deposit of the Chelyabinsk region, native copper is observed in vein-like bodies of diopside-garnet rocks occurring among serpentinites; for native copper it is characterized by association with cuprous gold, chalcocite, calcite, diopside, apatite, sphene, magnetite, etc.
In some ancient volcanic rocks (melafirs, diabases, etc.), metamorphosed under the influence of vapors, gases and hydrothermal solutions, copper fills tonsils, forms cement between minerals of altered lava, fills voids and cracks; accompanied by hydrothermal minerals: analcime, lomontite, prehnite, datolite, adularia, chlorite, epidote, pumpeliite, quartz, calcite. The largest deposits of this type are located on the Kivino Peninsula in the Lake Superior region (Michigan, USA), where mineralization is confined to the Upper Proterozoic sequence. The main mass of copper is mined from melafirs and conglomerates, but the largest copper segregations (up to 400 tons and more) are found in calcite veins containing native silver and domeikite.

Mineral change.

The most common alteration products of native copper are cuprite, malachite, and azurite.

Place of Birth

Allocations of native copper were observed in the diabases of Novaya Zemlya, in the traps of the Siberian Platform, among the main effusive rocks in Italy, the Faroe Islands (Denmark), Nova Scotia (Canada) and other places. Representatives of rare types of hypogene deposits of native copper are the Franklin zinc-manganese deposit (New Jersey, USA) and the Longban and Jacobsberg manganese deposits (Sweden). Hypogenic, apparently, are the allocation of native copper weighing up to several tons from the previously developed Kalmaktas deposit in Kazakhstan, presented in museums with excellent samples.
In the oxidation zone, especially in its lower parts, native copper is mainly an early product of the alteration of copper sulfide minerals, mainly chalcocite. It composes predominantly irregularly shaped discharges, less often - crystals and dendritic aggregates.
Most often, native copper is accompanied by chalcocite, cuprite, calcite, and limonite. It is observed in a number of deposits in Kazakhstan (Dzhezkazgan, Berkara, Uspenskoye, etc.), Rudny Altai (Belousovskoye, Zyryanovskoye, Chudak, Talovskoye, etc.), the USA (Bisbee and Clifton-Morensee in Arizona, Tintik in Utah, etc.) .
Part of the native copper in the oxidation zone is formed by deposition from solutions containing copper sulfate. Such, for example, is native copper, which forms precipitates in cavities among limonite aggregates, sometimes in association with cuprite (Copper ore deposit, Sverdlovsk region, etc.). Native copper pseudomorphs are known, formed in the zone of oxidation after chalcocite, cuprite, antlerite, chalcanthite, azurite, calcite, aragonite and other minerals.
Particularly beautiful samples of native copper (crystals and dendritic aggregates) come from the Turin mines of the Sverdlovsk region.
In some mine workings, so-called cement copper is released from copper-containing waters on iron objects in the form of films and crusts. There are also known cases of copper formation on half-decayed remains of fasteners.
In an increased amount, native copper is observed in some sedimentary rocks (sandstones, clays, marls) containing plant remains, in the form of irregularly shaped segregations, sometimes in pseudomorphs on wood or in the form of concretions. Such, for example, are the Permian cupriferous sandstones of certain regions of Russia (the Urals, Tatarstan, etc.), the Naukata sandstones in Kyrgyzstan, and the Cretaceous cuprous sandstones of Korokoro and Kobritsos in Bolivia, and others.
The formation of native copper in some peat bogs is also associated with the recovery processes, for example, in the Sverdlovsk region - along the Lyovikha River in the Tagil River basin and in the Sysert region.
In the form of pebbles and grains, native copper is found in Russia in some placers: in the Urals, along the Yenisei, along the B. Sarkhoy River in Buryatia, along the Chorokh River in Georgia, on the Commander Islands and in other places. In the state of Connecticut (USA), native copper was found in glacial deposits in the form of segregations weighing up to 75 kg. Small, irregularly shaped precipitates of native copper are noted in the native iron of the Vengerovo meteorite in association with troilite.

Practical use

Important component some copper ores, sometimes the main copper mineral of such ores.

It is used in electrical engineering, instrument making; various alloys with copper (bronze, brass, cupronickel) are widely used.

Physical research methods

Differential thermal analysis

Main lines on radiographs:

ancient methods. It melts under the blowpipe. At a white heat temperature, it gradually oxidizes, turning the flame green.

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Crystal optical properties in thin preparations (sections)

In polished sections in reflected light pink. Reflectivity (in%): for green rays - 61, for orange - 83, for red - 89. Isotropic. Refractive indices (according to Kundt) in prisms for red light - 0.45, for white - 0.65, for blue - 0.95; in reflective light (according to Drude) for Na-light 0.641, for red - 0.580. The absorption coefficient for Na-light is 4.09, for red light - 5.24.

Copper. Somorodok

a) Density and hardness.

Metals of the copper subgroup, like alkali metals, have one free electron per metal ion-atom. It would seem that these metals should not differ much from alkali metals. But they, unlike alkali metals, have rather high melting points. The large difference in melting temperatures between the metals of these subgroups is explained by the fact that there is almost no free space between the ion-atoms of the metals of the copper subgroup, and they are located more closely. As a result, the number of free electrons per unit volume, the electron density, they have more. Consequently, the strength of the chemical bond they have more. Therefore, metals of the copper subgroup melt and boil at higher temperatures.

Metals of the copper subgroup have, in comparison with alkali metals, have greater hardness. This is explained by an increase in the electron density and a denser arrangement of atoms in the crystal lattice. It should be noted that the hardness and strength of metals depend on the correct arrangement of ion-atoms in the crystal lattice. In metals that we practically encounter, there are various kinds of violations of the correct arrangement of ion-atoms, for example, voids in the nodes of the crystal lattice. In addition, the metal consists of small crystals (crystallites), between which the bond is weakened. At the Academy of Sciences of the USSR, copper was obtained without disturbance in the crystal lattice. To do this, very pure copper was sublimated at high temperature in a deep vacuum onto a deep substrate. Copper was obtained in the form of small threads - “whiskers”. As it turned out, such copper is a hundred times stronger than ordinary copper.

b) The color of copper and its compounds.

Pure copper has another interesting feature. The red color is due to traces of oxygen dissolved in it. It turned out that copper repeatedly sublimated in a vacuum (in the absence of oxygen) has a yellowish color. Copper in a polished state has a strong luster.

With an increase in valency, the color of copper and its compounds darkens, for example, CuCl- white, Cu 2 O- red, CuCl + H 2 O- blue, CuO- black. Carbonates are characterized by blue and green colors, subject to water content, which is an interesting practical feature for searching.

c) Electrical conductivity.

Copper has the highest (after silver) electrical conductivity, which is the reason for its extensive use in electronics.

d) Crystal lattice.

Copper crystallizes in the form of a centralized cube (Fig. 1).

Figure 1. Crystal lattice of copper.

e) Isotopes.

Natural copper consists of two stable isotopes, 63 Cu and 65 Cu, with abundances of 69.1 and 30.9 atomic percent, respectively. More than two dozen unstable isotopes are known, the longest-lived of which is 67 Cu with a half-life of 62 hours.

§four. copper alloys.

Copper alloys are the first metal alloys created by man. Until about the middle of the 20th century. in world production, copper alloys occupied the 1st place among non-ferrous metal alloys, then losing it to aluminum alloys. With many elements copper forms broad areas substitutional solid solutions in which additive atoms take the place of copper atoms in a face-centered cubic lattice. Copper in the solid state dissolves up to 39% Zn, 15.8% Sn, 9.4% Al, and Ni - unlimitedly. When a copper-based solid solution is formed, its strength and electrical resistance increase, the temperature coefficient of electrical resistance decreases, corrosion resistance can significantly increase, and ductility remains at a fairly high level.

Currently, there are countless copper-based alloys, here I will give the three most basic and common alloys in technology and everyday life:

a) brass

Brass is a copper alloy with zinc added. Zinc, the content of which in the composition can reach up to 40%, increases the strength and ductility of the alloy. The most ductile brass, with a zinc content of about 30%. It is used for the production of wire and thin sheets. The composition may also include iron, tin, lead, nickel, manganese and other components. They increase the corrosion resistance and mechanical properties of the alloy. Brass is well processed: welding and rolling, perfectly polished. A wide range of properties, low cost, ease of processing and a beautiful yellow color make brass the most common copper alloy with a wide range of applications.

b) Bronze

Bronzes are an alloy of copper, usually with tin as the main alloying component, but bronzes also include copper alloys with aluminum, silicon, beryllium, lead and other elements, with the exception of zinc (this is brass) and nickel. As a rule, any bronze contains small amounts of additives: zinc, lead, phosphorus, etc.

People learned to smelt traditional tin bronze at the beginning of the Bronze Age and for a very long time it was widely used; even with the advent of the iron age, bronze did not lose its importance (in particular, until the 19th century, guns were made from gunmetal)

The most widely used bronzes are: silicon bronzes, beryllium bronzes, silicon bronzes, chromium bronzes, but by far the best known and most applicable is tin bronze.

c) Copper-nickel alloys

Copper-based alloys containing nickel as the main alloying element - Melchior, German silver (copper alloy with 5-35% Ni and 13-45% Zn). Nickel forms a continuous series of solid solutions with copper. When nickel is added to copper, its strength and electrical resistance increase, the temperature coefficient of electrical resistance decreases, and corrosion resistance is greatly increased. Copper-nickel alloys work well in hot and cold pressure.

Copper is a metal that belongs to the non-ferrous group, because it has a bright reddish-pink color, with varying degrees of processing it can have a brown, green, golden hue. This metal has high electrolytic properties, thermal conductivity, strength and elasticity. Copper is easy to process, is part of many alloys, thereby increasing its chemical and physical properties. The most famous alloys are bronze - 7 - 10% tin is added to the bulk of copper, a copper-nickel alloy - constants (in the total mass up to 40% nickel) and manganin (nickel and manganese are included in the alloy). The presence of a large number of distinctive characteristics and the availability of metal determine the widespread use of copper in various industries, agriculture, construction, medicine.

How copper is used in industry

Copper is smelted in industry

In the production of various products, I use copper in its pure form and in the form of alloys with various metals. The pure metal is used to make network cables and power wires. Copper is characterized by its ability to conduct electricity quickly and without loss. According to this indicator, it is second only to silver, but since it belongs to precious metals and has a high cost, the use of copper is preferred in electrical wiring. Only pure metal is used for the production of the cable core - copper core, the presence of any impurities significantly reduces the conductive effect. To obtain pure copper, its blanks are subjected to the process of electrorefining. It is the immersion of metal in a bath filled with a solution of copper sulfate, and an electrode connected to electricity is immersed there. The metal ions move towards the electrode, and the impurity particles collect near the anode, so they can be removed, and the output is a material with a content of 99.999% pure copper.

Copper-nickel alloys are characterized by high electrical resistance and are used in instrument making. These alloys are resistant to corrosion, do not collapse even in sea water. An alloy in which 40% zinc is called brass, it has increased strength, and its low cost leads to widespread use:

• in mechanical engineering;
• in the production of household goods;
• in the chemical industry.

Made from brass:

• pipes;
• radiators;
• sleeves;
• automotive accessories and more.

Copper plating is used for chrome plating of steel. Steel products are often coated with chromium or nickel for decorative purposes, but this coating is short-lived and may fall off during operation, in order to avoid this, copper coating is applied between the steel and the chrome layer, it provides better adhesion.

The use of copper in industry can also be observed during soldering, it greatly facilitates this process, and the part is homogeneous and durable. This metal is quite ductile, it can be used for the manufacture of water pipes of various configurations, in Russia the use of such pipes is not widespread, but in Europe such products can be found quite often.

Copper products in everyday life

This metal is used not only for the production of industrial goods, copper products can also be found in everyday life:

All these items can be found in almost every home.

An important role in agriculture is played by soil fertilizers containing blue vitriol- it stimulates the active growth of various crops, protects them from pests, trees, shrubs, seeds are treated with vitriol solution.

Interior items made of copper

During the construction of houses, copper sheets are used in roofing. It is known that given metal resistant to various atmospheric phenomena, under their influence a protective layer is formed - patina, which has a greenish tint. Patina prevents metal corrosion, and a roof with such a coating can serve for a long time.

copper coins

Electroplating can also be attributed to the scope of copper, it has been known since 1873. Electroplating is a special kind of art based on the electrolytic deposition of metal in an aqueous salt solution. This method has long gone beyond art and is used in space industry, aviation, mechanical engineering. Its essence lies in the fact that the created model of the product, for example, from gypsum or plasticine, is metallized, after removing the model, only the metal form remains. The metallization process occurs by applying a thin layer of metal to the layout, graphite is more often used, the workpiece is placed in a solution that contains copper salts. The layout plays the role of a cathode and attracts metal particles, which later form the shape of the finished product.

The use of copper in medicine

Traditional medicine considers copper to be a very important element in human life. In the body, this substance is contained in an amount of 2 * 10 -4% of the total mass. Every day a person consumes up to 60 mg of copper with food, of which approximately 2 mg is absorbed, which is the necessary norm for a healthy body. Copper plays an important role in the biosynthesis of hemoglobin, in maintaining the level of sugar, cholesterol and uric acid. Copper is necessary for the normal functioning of the cardiovascular system, brain, and digestive tract. In case of its deficiency, it develops:

• for the treatment of acute insufficiency, drugs containing this microelement are used;
• in therapy - the use of metal applications or bracelets.

The largest amount of trace elements is found in foods such as:

• champignons;
• potato;
• Cod liver;
• whole grain;
• oysters and cuttlefish.

At the same time, an excess of copper in the body, when its amount exceeds 250 mg, leads to intoxication and disruption of the liver, the development of Wilson's disease, anemia.

Video: How a copper cable is made

• Designation - Cu (Copper);
• Period - IV;
• Group - 11 (Ib);
• Atomic mass - 63.546;
• Atomic number - 29;
• Radius of an atom = 128 pm;
• Covalent radius = 117 pm;
• Electron distribution - 1s 2 2s 2 2p 6 3s 2 3p 6 3d 10 4s 1 ;
• t melting = 1083.4°C;
• boiling point = 2567°C;
• Electronegativity (according to Pauling / according to Alpred and Rochov) = 1.90 / 1.75;
• Oxidation state: +3, +2, +1, 0;
• Density (n.a.) \u003d 8.92 g / cm 3;
• Molar volume = 7.1 cm 3 / mol.

Copper (cuprum, got its name in honor of the island of Cyprus, where there was a large open copper deposit) is one of the first metals that people mastered - the Copper Age (the era when copper tools prevailed in everyday life) covers the period IV-III millennium BC . e.

An alloy of copper and tin (bronze) was obtained in the Middle East in 3000 BC. e. Bronze was preferred over copper because it was stronger and easier to forge.

Rice. The structure of the copper atom.

The electronic configuration of the copper atom is 1s 2 2s 2 2p 6 3s 2 3p 6 3d 10 4s 1 (see Electronic structure of atoms). In copper, one paired electron from the outer s-level "jumps" to the d-sublevel of the pre-outer orbital, which is associated with the high stability of the completely filled d-level. The completed stable d-sublevel of copper determines its relative chemical inertness (copper does not react with hydrogen, nitrogen, carbon, silicon). Copper in compounds can exhibit oxidation states +3, +2, +1 (the most stable are +1 and +2).

Rice. Electronic configuration of copper.

Physical properties of copper:

• metal, red-pink;
• has high ductility and ductility;
• good electrical conductivity;
• low electrical resistance.

Chemical properties of copper

• when heated, it reacts with oxygen:
  O 2 + 2Cu = 2CuO;
• when exposed to air for a long time, it reacts with oxygen even at room temperature:
  O 2 + 2Cu + CO 2 + H 2 O \u003d Cu (OH) 2 CuCO 3;
• reacts with nitric and concentrated sulfuric acid:
  Cu + 2H 2 SO 4 \u003d CuSO 4 + SO 2 + 2H 2 O;
• copper does not react with water, alkali solutions, hydrochloric and dilute sulfuric acid.

Copper compounds

Copper oxide CuO(II):

• red-brown solid, insoluble in water, showing basic properties;
• when heated in the presence of reducing agents gives free copper:
  CuO + H 2 \u003d Cu + H 2 O;
• copper oxide is obtained by the interaction of copper with oxygen or the decomposition of copper (II) hydroxide:
  O 2 + 2Cu = 2CuO; Cu (OH) 2 \u003d CuO + H 2 O.

Copper hydroxide Cu (OH 2) (II):

• blue crystalline or amorphous substance, insoluble in water;
• decomposes into water and copper oxide when heated;
• reacts with acids to form the corresponding salts:
  Cu(OH 2) + H 2 SO 4 = CuSO 4 + 2H 2 O;
• reacts with alkali solutions, forming cuprates - bright blue complex compounds:
  Cu (OH 2) + 2KOH \u003d K 2.

For copper compounds, see Copper oxides.

Obtaining and using copper

• pyrometallurgical method copper is obtained from sulfide ores at high temperatures:
  CuFeS 2 + O 2 + SiO 2 → Cu + FeSiO 3 + SO 2;
• copper oxide is reduced to metallic copper by hydrogen, carbon monoxide, active metals:
  Cu 2 O + H 2 \u003d 2Cu + H 2 O;
  Cu 2 O + CO \u003d 2Cu + CO 2;
  Cu 2 O + Mg \u003d 2Cu + MgO.

The use of copper is due to its high electrical and thermal conductivity, as well as ductility:

• production of electrical wires and cables;
• in heat exchange equipment;
• in metallurgy to obtain alloys: bronze, brass, cupronickel;
• in radio electronics.