Copper - what kind of metal it is and where it is used. Copper as a metal and raw material in construction: its features and processing nuances Material copper

Copper is an element of the secondary subgroup of the first group, the fourth period of the periodic system of chemical elements of D.I. Mendeleev, with atomic number 29. It is designated by the symbol Cu (lat. Cuprum). The simple substance copper (CAS number: 7440-50-8) is a ductile transition metal of a golden-pink color (pink in the absence of an oxide film). It has been widely used by people for a long time.

History and origin of the name

Copper is one of the first metals widely mastered by man due to its comparative availability from ore and low melting point. In ancient times it was used mainly in the form of an alloy with tin - bronze for the manufacture of weapons, etc. (see Bronze Age).
The Latin name for copper Cuprum (ancient Aes cuprium, Aes cyprium) comes from the name of the island of Cyprus, where already in the 3rd millennium BC. e. There were copper mines and copper smelting was carried out.
Strabo calls copper chalkos, from the name of the city of Chalkis on Euboea. From this word came many ancient Greek names for copper and bronze objects, blacksmithing, blacksmithing and casting. The second Latin name for copper Aes (Sanskrit, ayas, Gothic aiz, German erz, English ore) means ore or mine. Proponents of the Indo-Germanic theory of the origin of European languages ​​derive the Russian word copper (Polish miedz, Czech med) from Old German smida (metal) and Schmied (blacksmith, English Smith). Of course, the relationship of the roots in this case is undoubtedly, however, both of these words are derived from the Greek. mine, mine independently of each other. From this word came related names - medal, medallion (French medaille). The words copper and copper are found in the most ancient Russian literary monuments. Alchemists called copper Venus. In more ancient times the name Mars was found.

Physical properties

Copper is a golden-pink ductile metal; in air it quickly becomes covered with an oxide film, which gives it a characteristic intense yellowish-red hue. Thin films of copper have a greenish-blue color when exposed to light.
Copper forms a cubic face-centered lattice, space group F m3m, a = 0.36150 nm, Z = 4.
Copper has high thermal and electrical conductivity (it ranks second in electrical conductivity after silver).
It has two stable isotopes - 63 Cu and 65 Cu, and several radioactive isotopes. The longest-lived of these, 64 Cu, has a half-life of 12.7 hours and two decay modes with different products.
There are a number of copper alloys: brass - with zinc, bronze - with tin and other elements, cupronickel - with nickel, babbit - with lead and others.

Chemical properties

Does not change in air in the absence of moisture and carbon dioxide. It is a weak reducing agent and does not react with water diluted with hydrochloric acid. It is transferred into solution with non-oxidizing acids or ammonia hydrate in the presence of oxygen, potassium cyanide. It is oxidized by concentrated sulfuric and nitric acids, aqua regia, oxygen, halogens, chalcogens, and non-metal oxides. Reacts when heated with hydrogen halides.

Modern mining methods

90% of primary copper is obtained by pyrometallurgical method, 10% - by hydrometallurgical method. The hydrometallurgical method is the production of copper by leaching it with a weak solution of sulfuric acid and subsequent separation of copper metal from the solution. The pyrometallurgical method consists of several stages: enrichment, roasting, smelting for matte, purging in a converter, refining.
To enrich copper ores, the flotation method is used (based on the use of different wettability of copper-containing particles and waste rock), which allows one to obtain copper concentrate containing from 10 to 35% copper.
Copper ores and concentrates with high sulfur content are subjected to oxidative roasting. In the process of heating the concentrate or ore to 700-800 °C in the presence of atmospheric oxygen, sulfides are oxidized and the sulfur content is reduced by almost half of the original. Only poor concentrates (with a copper content of 8 to 25%) are fired, and rich concentrates (from 25 to 35% copper) are melted without firing.
After roasting, the ore and copper concentrate are smelted into matte, which is an alloy containing copper and iron sulfides. Matte contains from 30 to 50% copper, 20-40% iron, 22-25% sulfur, in addition, matte contains impurities of nickel, zinc, lead, gold, and silver. Most often, smelting is carried out in fiery reverberatory furnaces. The temperature in the melting zone is 1450 °C.
In order to oxidize sulfides and iron, the resulting copper matte is subjected to blowing with compressed air in horizontal converters with side blast. The resulting oxides are converted into slag. The temperature in the converter is 1200-1300 °C. Interestingly, heat is released in the converter due to chemical reactions, without fuel supply. Thus, the converter produces blister copper containing 98.4 - 99.4% copper, 0.01 - 0.04% iron, 0.02 - 0.1% sulfur and a small amount of nickel, tin, antimony, silver, gold. This copper is poured into a ladle and poured into steel molds or a casting machine.
Next, to remove harmful impurities, blister copper is refined (fire refining and then electrolytic refining are carried out). The essence of fire refining of blister copper is the oxidation of impurities, removing them with gases and converting them into slag. After fire refining, copper with a purity of 99.0 - 99.7% is obtained. It is poured into molds and ingots are obtained for further smelting of alloys (bronze and brass) or ingots for electrolytic refining.
Electrolytic refining is carried out to obtain pure copper (99.95%). Electrolysis is carried out in baths where the anode is made of fire-refined copper, and the cathode is made of thin sheets of pure copper. The electrolyte is an aqueous solution. When a direct current is passed, the anode dissolves, the copper goes into solution, and, cleaned of impurities, is deposited on the cathodes. Impurities settle to the bottom of the bath in the form of slag, which is processed to extract valuable metals. The cathodes are unloaded after 5-12 days, when their weight reaches 60 to 90 kg. They are thoroughly washed and then melted in electric furnaces.

§1. Chemical properties of a simple substance (st. approx. = 0).

a) Relation to oxygen.

Unlike its subgroup neighbors - silver and gold - copper reacts directly with oxygen. Copper exhibits insignificant activity towards oxygen, but in humid air it gradually oxidizes and becomes covered with a greenish film consisting of basic copper carbonates:

In dry air, oxidation occurs very slowly, and a thin layer of copper oxide forms on the surface of the copper:

Externally, copper does not change, since copper oxide (I), like copper itself, is pink. In addition, the oxide layer is so thin that it transmits light, i.e. shines through. Copper oxidizes differently when heated, for example, at 600-800 0 C. In the first seconds, oxidation proceeds to copper (I) oxide, which from the surface turns into black copper (II) oxide. A two-layer oxide coating is formed.

Q formation (Cu 2 O) = 84935 kJ.

Figure 2. Structure of the copper oxide film.

b) Interaction with water.

Metals of the copper subgroup are at the end of the electrochemical voltage series, after the hydrogen ion. Therefore, these metals cannot displace hydrogen from water. At the same time, hydrogen and other metals can displace metals of the copper subgroup from solutions of their salts, for example:

This reaction is redox, as electrons are transferred:

Molecular hydrogen displaces metals of the copper subgroup with great difficulty. This is explained by the fact that the bond between hydrogen atoms is strong and a lot of energy is spent on breaking it. The reaction occurs only with hydrogen atoms.

In the absence of oxygen, copper practically does not interact with water. In the presence of oxygen, copper slowly reacts with water and becomes covered with a green film of copper hydroxide and basic carbonate:

c) Interaction with acids.

Being in the voltage series after hydrogen, copper does not displace it from acids. Therefore, hydrochloric and dilute sulfuric acid have no effect on copper.

However, in the presence of oxygen, copper dissolves in these acids to form the corresponding salts:

The only exception is hydroiodic acid, which reacts with copper to release hydrogen and form a very stable copper (I) complex:

2 Cu + 3 HI → 2 H[ CuI 2 ] + H 2

Copper also reacts with oxidizing acids, for example, nitric acid:

Cu + 4HNO 3( conc. .) → Cu(NO 3 ) 2 +2NO 2 +2H 2 O

3Cu + 8HNO 3( diluting .) → 3Cu(NO 3 ) 2 +2NO+4H 2 O

And also with concentrated cold sulfuric acid:

Cu+H 2 SO 4(conc.) → CuO + SO 2 +H 2 O

With hot concentrated sulfuric acid :

Cu+2H 2 SO 4( conc. ., hot ) → CuSO 4 + SO 2 + 2H 2 O

With anhydrous sulfuric acid at a temperature of 200 0 C, copper (I) sulfate is formed:

2Cu + 2H 2 SO 4( anhydrous .) 200 °C → Cu 2 SO 4 ↓+SO 2 + 2H 2 O

d) Relation to halogens and some other non-metals.

Q formation (CuCl) = 134300 kJ

Q formation (CuCl 2) = 111700 kJ

Copper reacts well with halogens and produces two types of halides: CuX and CuX 2 .. When exposed to halogens at room temperature, no visible changes occur, but a layer of adsorbed molecules first forms on the surface, and then a thin layer of halides. When heated, the reaction with copper occurs very violently. We heat the copper wire or foil and lower it hot into a jar of chlorine - brown vapors will appear near the copper, consisting of copper (II) chloride CuCl 2 with an admixture of copper (I) chloride CuCl. The reaction occurs spontaneously due to the heat released. Monivalent copper halides are obtained by reacting copper metal with a solution of cuprous halide, for example:

In this case, the monochloride precipitates from solution in the form of a white precipitate on the surface of the copper.

Copper also reacts quite easily with sulfur and selenium when heated (300-400 °C):

2Cu +S→Cu 2 S

2Cu +Se→Cu 2 Se

But copper does not react with hydrogen, carbon and nitrogen even at high temperatures.

e) Interaction with non-metal oxides

When heated, copper can displace simple substances from some non-metal oxides (for example, sulfur (IV) oxide and nitrogen oxides (II, IV)), thereby forming a thermodynamically more stable copper (II) oxide:

4Cu+SO 2 600-800°C →2CuO + Cu 2 S

4Cu+2NO 2 500-600°C →4CuO + N 2

2 Cu+2 NO 500-600° C →2 CuO + N 2

§2. Chemical properties of monovalent copper (st. ok. = +1)

In aqueous solutions, the Cu + ion is very unstable and disproportionates:

Cu + ↔ Cu 0 + Cu 2+

However, copper in the (+1) oxidation state can be stabilized in compounds with very low solubility or through complexation.

a) Copper oxide (I) Cu 2 O

Amphoteric oxide. Brown-red crystalline substance. It occurs in nature as the mineral cuprite. It can be artificially obtained by heating a solution of a copper (II) salt with an alkali and some strong reducing agent, for example, formaldehyde or glucose. Copper(I) oxide does not react with water. Copper(I) oxide is transferred into solution with concentrated hydrochloric acid to form a chloride complex:

Cu 2 O+4 HCl→2 H[ CuCl2]+ H 2 O

Also soluble in a concentrated solution of ammonia and ammonium salts:

Cu 2 O+2NH 4 + →2 +

In dilute sulfuric acid it disproportionates into divalent copper and metallic copper:

Cu 2 O+H 2 SO 4(diluted) →CuSO 4 +Cu 0 ↓+H 2 O

Also, copper(I) oxide enters into the following reactions in aqueous solutions:

1. Slowly oxidized by oxygen to copper(II) hydroxide:

2 Cu 2 O+4 H 2 O+ O 2 →4 Cu(OH) 2 ↓

2. Reacts with dilute hydrohalic acids to form the corresponding copper(I) halides:

Cu 2 O+2 HГ→2CuГ↓ +H 2 O(G=Cl, Br, J)

3. Reduced to metallic copper with typical reducing agents, for example, sodium hydrosulfite in a concentrated solution:

2 Cu 2 O+2 NaSO 3 →4 Cu↓+ Na 2 SO 4 + H 2 SO 4

Copper(I) oxide is reduced to copper metal in the following reactions:

1. When heated to 1800 °C (decomposition):

2 Cu 2 O - 1800° C →2 Cu + O 2

2. When heated in a stream of hydrogen, carbon monoxide, with aluminum and other typical reducing agents:

Cu 2 O+H 2 - >250°C →2Cu +H 2 O

Cu 2 O+CO - 250-300°C →2Cu +CO 2

3 Cu 2 O + 2 Al - 1000° C →6 Cu + Al 2 O 3

Also, at high temperatures, copper(I) oxide reacts:

1. With ammonia (copper(I) nitride is formed)

3 Cu 2 O + 2 N.H. 3 - 250° C →2 Cu 3 N + 3 H 2 O

2. With alkali metal oxides:

Cu 2 O+M 2 O- 600-800°C →2 MCuO (M= Li, Na, K)

In this case, copper (I) cuprates are formed.

Copper(I) oxide reacts noticeably with alkalis:

Cu 2 O+2 NaOH (conc.) + H 2 O↔2 Na[ Cu(OH) 2 ]

b) Copper hydroxide (I) CuOH

Copper(I) hydroxide forms a yellow substance and is insoluble in water.

Easily decomposes when heated or boiled:

2 CuOH → Cu 2 O + H 2 O

c) HalidesCuF, CuWITHl, CuBrAndCuJ

All these compounds are white crystalline substances, poorly soluble in water, but highly soluble in excess NH 3, cyanide ions, thiosulfate ions and other strong complexing agents. Iodine forms only the compound Cu +1 J. In the gaseous state, cycles of the type (CuГ) 3 are formed. Reversibly soluble in the corresponding hydrohalic acids:

CuG + HG ↔H[ CuG 2 ] (Г=Cl, Br, J)

Copper(I) chloride and bromide are unstable in moist air and gradually transform into basic copper(II) salts:

4 CuG +2H 2 O + O 2 →4 Cu(OH)G (G=Cl, Br)

d) Other copper compounds (I)

1. Copper (I) acetate (CH 3 COOCu) is a copper compound that appears as colorless crystals. In water it slowly hydrolyzes to Cu 2 O, in air it is oxidized to cupric acetate; CH 3 COOCu is obtained by reduction of (CH 3 COO) 2 Cu with hydrogen or copper, sublimation of (CH 3 COO) 2 Cu in vacuum or interaction of (NH 3 OH)SO 4 with (CH 3 COO) 2 Cu in solution in the presence of H 3 COONH 3 . The substance is toxic.

2. Copper(I) acetylide - red-brown, sometimes black crystals. When dry, the crystals detonate when struck or heated. Stable when wet. When detonation occurs in the absence of oxygen, no gaseous substances are formed. Decomposes under the influence of acids. Formed as a precipitate when passing acetylene into ammonia solutions of copper(I) salts:

WITH 2 H 2 +2[ Cu(N.H. 3 ) 2 ](OH) → Cu 2 C 2 ↓ +2 H 2 O+2 N.H. 3

This reaction is used for the qualitative detection of acetylene.

3. Copper nitride - an inorganic compound with the formula Cu 3 N, dark green crystals.

Decomposes when heated:

2 Cu 3 N - 300° C →6 Cu + N 2

Reacts violently with acids:

2 Cu 3 N +6 HCl - 300° C →3 Cu↓ +3 CuCl 2 +2 N.H. 3

§3. Chemical properties of divalent copper (st. ok. = +2)

Copper has the most stable oxidation state and is the most characteristic of it.

a) Copper oxide (II) CuO

CuO is the main oxide of divalent copper. The crystals are black in color, quite stable under normal conditions, and practically insoluble in water. It occurs in nature as the black mineral tenorite (melaconite). Copper(II) oxide reacts with acids to form the corresponding copper(II) salts and water:

CuO + 2 HNO 3 → Cu(NO 3 ) 2 + H 2 O

When CuO is fused with alkalis, copper (II) cuprates are formed:

CuO+2 KOH- t ° → K 2 CuO 2 + H 2 O

When heated to 1100 °C, it decomposes:

4CuO- t ° →2 Cu 2 O + O 2

b) Copper (II) hydroxideCu(OH) 2

Copper(II) hydroxide is a blue amorphous or crystalline substance, practically insoluble in water. When heated to 70-90 °C, Cu(OH)2 powder or its aqueous suspensions decomposes to CuO and H2O:

Cu(OH) 2 → CuO + H 2 O

It is an amphoteric hydroxide. Reacts with acids to form water and the corresponding copper salt:

It does not react with dilute solutions of alkalis, but dissolves in concentrated solutions, forming bright blue tetrahydroxycuprates (II):

Copper(II) hydroxide forms basic salts with weak acids. Dissolves very easily in excess ammonia to form copper ammonia:

Cu(OH) 2 +4NH 4 OH→(OH) 2 +4H 2 O

Copper ammonia has an intense blue-violet color, so it is used in analytical chemistry to determine small amounts of Cu 2+ ions in solution.

c) Copper salts (II)

Simple salts of copper (II) are known for most anions, except cyanide and iodide, which, when interacting with the Cu 2+ cation, form covalent copper (I) compounds that are insoluble in water.

Copper (+2) salts are mainly soluble in water. The blue color of their solutions is associated with the formation of the 2+ ion. They often crystallize as hydrates. Thus, from an aqueous solution of copper (II) chloride below 15 0 C, tetrahydrate crystallizes, at 15-26 0 C - trihydrate, above 26 0 C - dihydrate. In aqueous solutions, copper(II) salts are slightly hydrolyzed, and basic salts often precipitate from them.

1. Copper (II) sulfate pentahydrate (copper sulfate)

Of greatest practical importance is CuSO 4 * 5H 2 O, called copper sulfate. Dry salt has a blue color, but when slightly heated (200 0 C), it loses water of crystallization. Anhydrous salt is white. With further heating to 700 0 C, it turns into copper oxide, losing sulfur trioxide:

CuSO 4 ­-- t ° → CuO+ SO 3

Copper sulfate is prepared by dissolving copper in concentrated sulfuric acid. This reaction is described in the section "Chemical properties of a simple substance." Copper sulfate is used in the electrolytic production of copper, in agriculture to control pests and plant diseases, and for the production of other copper compounds.

2. Copper (II) chloride dihydrate.

These are dark green crystals, easily soluble in water. Concentrated solutions of copper chloride are green, and diluted solutions are blue. This is explained by the formation of a green chloride complex:

Cu 2+ +4 Cl - →[ CuCl 4 ] 2-

And its further destruction and the formation of a blue aqua complex.

3. Copper(II) nitrate trihydrate.

Blue crystalline substance. It is obtained by dissolving copper in nitric acid. When heated, the crystals first lose water, then decompose with the release of oxygen and nitrogen dioxide, turning into copper (II) oxide:

2Cu(NO 3 ) 2 -- t° →2CuO+4NO 2 +O 2

4. Hydroxocopper (II) carbonate.

Copper carbonates are unstable and are almost never used in practice. Only the basic copper carbonate Cu 2 (OH) 2 CO 3, which occurs in nature in the form of the mineral malachite, is of some importance for the production of copper. When heated, it easily decomposes, releasing water, carbon monoxide (IV) and copper oxide (II):

Cu 2 (OH) 2 CO 3 -- t° →2CuO+H 2 O+CO 2

§4. Chemical properties of trivalent copper (st. ok. = +3)

This oxidation state is the least stable for copper, and copper(III) compounds are therefore the exception rather than the "rule". However, some trivalent copper compounds do exist.

a) Copper (III) oxide Cu 2 O 3

This is a crystalline substance, dark garnet in color. Does not dissolve in water.

It is obtained by oxidation of copper(II) hydroxide with potassium peroxodisulfate in an alkaline medium at negative temperatures:

2Cu(OH) 2 +K 2 S 2 O 8 +2KOH -- -20°C →Cu 2 O 3 ↓+2K 2 SO 4 +3H 2 O

This substance decomposes at a temperature of 400 0 C:

Cu 2 O 3 -- t ° →2 CuO+ O 2

Copper(III) oxide is a strong oxidizing agent. When reacting with hydrogen chloride, chlorine is reduced to free chlorine:

Cu 2 O 3 +6 HCl-- t ° →2 CuCl 2 + Cl 2 +3 H 2 O

b) Copper cuprates (C)

These are black or blue substances, unstable in water, diamagnetic, the anion is a ribbon of squares (dsp 2). Formed by the interaction of copper(II) hydroxide and alkali metal hypochlorite in an alkaline environment:

2 Cu(OH) 2 + MClO + 2 NaOH→2MCuO 3 + NaCl +3 H 2 O (M= Na- Cs)

c) Potassium hexafluorocuprate(III)

Green substance, paramagnetic. Octahedral structure sp 3 d 2. Copper fluoride complex CuF 3, which in a free state decomposes at -60 0 C. It is formed by heating a mixture of potassium and copper chlorides in a fluorine atmosphere:

3KCl + CuCl + 3F 2 →K 3 + 2Cl 2

Decomposes water to form free fluorine.

§5. Copper compounds in oxidation state (+4)

So far, science knows only one substance where copper is in the oxidation state +4, this is cesium hexafluorocuprate(IV) - Cs 2 Cu +4 F 6 - an orange crystalline substance, stable in glass ampoules at 0 0 C. It reacts violently with water. It is obtained by fluoridation at high pressure and temperature of a mixture of cesium and copper chlorides:

CuCl 2 +2CsCl +3F 2 -- t ° r → Cs 2 CuF 6 +2Cl 2

Which refers to non-ferrous metals, has been known for a long time. Its production was invented before people began to make iron. It is believed to have occurred as a result of its availability and fairly simple extraction from copper-containing compounds and alloys. So, let's look today at the properties and composition of copper, the world's leading countries in copper production, the manufacture of products from it and the features of these areas.

Copper has a high coefficient of electrical conductivity, which has increased its value as an electrical material. If previously up to half of all copper produced in the world was spent on electrical wires, now aluminum is used for these purposes as a more affordable metal. And copper itself becomes the most scarce non-ferrous metal.

This video discusses the chemical composition of copper:

Structure

The structural composition of copper includes many crystals: gold, calcium, silver, and many others. All metals included in its structure are distinguished by relative softness, ductility and ease of processing. Most of these crystals, when combined with copper, form solid solutions with continuous rows.

The unit cell of this metal is cubic in shape. For each such cell there are four atoms located at the vertices and the central part of the face.

Chemical composition

The composition of copper during its production may include a number of impurities that affect the structure and characteristics of the final product. At the same time, their content should be regulated both by individual elements and by their total quantity. Impurities that are found in copper include:

• Bismuth. This component negatively affects both the technological and mechanical properties of the metal. That is why it should not exceed 0.001% of the finished composition.
• Oxygen. It is considered the most undesirable impurity in copper. Its maximum content in the alloy is up to 0.008% and rapidly decreases when exposed to high temperatures. Oxygen negatively affects the ductility of the metal, as well as its resistance to corrosion.
• Manganese. In the case of the manufacture of conductive copper, this component negatively affects its conductivity. Already at room temperature it quickly dissolves in copper.
• Arsenic. This component creates a solid solution with copper and has virtually no effect on its properties. Its action is largely aimed at neutralizing the negative effects of antimony, bismuth and oxygen.
• . Forms a solid solution with copper and at the same time reduces its thermal and electrical conductivity.
• . Creates a solid solution and enhances thermal conductivity.
• Selenium, sulfur. These two components have the same effect on the final product. They form a fragile connection with copper and amount to no more than 0.001%. As the concentration increases, the degree of ductility of copper sharply decreases.
• Antimony. This component is highly soluble in copper and therefore has minimal impact on its final properties. It is allowed no more than 0.05% of the total volume.
• Phosphorus. Serves as the main deoxidizer of copper, the maximum solubility of which is 1.7% at a temperature of 714°C. Phosphorus, in combination with copper, not only promotes better welding, but also improves its mechanical properties.
• . Contained in a small amount of copper, it has virtually no effect on its thermal and electrical conductivity.

Copper production

Copper is produced from sulfide ores, which contain at least 0.5% of this copper. In nature, there are about 40 minerals containing this metal. The most common sulfide mineral actively used in copper production is chalcopyrite.

To produce 1 ton of copper, you need to take a huge amount of raw materials that contain it. Take, for example, the production of cast iron; to obtain 1 ton of this metal, it will be necessary to process about 2.5 tons of iron ore. And to obtain the same amount of copper, it will be necessary to process up to 200 tons of ore containing it.

The video below will tell you about copper mining:

Technology and necessary equipment

Copper production involves a number of stages:

1. Grinding of ore in special crushers and its subsequent more thorough grinding in ball-type mills.
2. Flotation. The pre-crushed raw material is mixed with a small amount of flotation reagent and then placed in a flotation machine. This additional component is usually potassium and lime xanthate, which is coated with copper minerals in the machine chamber. The role of lime at this stage is extremely important, since it prevents the envelopment of xanthate by particles of other minerals. Only air bubbles stick to the copper particles, which carry it to the surface. As a result of this process, a copper concentrate is obtained, which is directed to remove excess moisture from its composition.
3. Burning. Ores and their concentrates undergo a roasting process in monopod furnaces, which is necessary to remove sulfur from them. The result is cinder and sulfur-containing gases, which are subsequently used to produce sulfuric acid.
4. Melting of the charge in a reflective furnace. At this stage, you can take raw or already fired mixture and fire it at a temperature of 1500°C. An important operating condition is to maintain a neutral atmosphere in the furnace. As a result, copper is sulfided and converted into matte.
5. Conversion. The resulting copper in combination with quartz flux is blown in a special convector for 15-24 hours. The result is blister copper as a result of complete burnout of sulfur and removal of gases. It may contain up to 3% of various impurities, which are removed due to electrolysis.
6. Refining by fire. The metal is pre-melted and then refined in special furnaces. The output is red copper.
7. Electrolytic refining. The anodic and flame copper goes through this stage for maximum purification.

Read below about copper factories and centers in Russia and around the world.

Famous manufacturers

There are only four largest copper mining and production enterprises in Russia:

1. "Norilsk Nickel";
2. "Uralelectromed";
3. Novgorod Metallurgical Plant;
4. Kyshtym copper electrolyte plant.

The first two companies are part of the famous UMMC holding, which includes about 40 industrial enterprises. It produces more than 40% of all copper in our country. The last two plants belong to the Russian Copper Company.

The video below will tell you about copper production:

DEFINITION

Copper- the twenty-ninth element of the Periodic Table. Designation - Cu from the Latin "cuprum". Located in the fourth period, IB group. Refers to metals. The nuclear charge is 29.

The most important minerals that make up copper ores are: chalcocite, or copper luster Cu 2 S; chalcopyrite, or copper pyrite CuFeS 2; malachite (CuOH) 2 CO 3 .

Pure copper is a viscous, viscous metal of light pink color (Fig. 1), easily rolled into thin sheets. It conducts heat and electricity very well, second only to silver in this regard. In dry air, copper remains almost unchanged, since the thin film of oxides that forms on its surface (giving copper a darker color) serves as good protection against further oxidation. But in the presence of moisture and carbon dioxide, the copper surface becomes covered with a greenish coating of hydroxycopper carbonate (CuOH) 2 CO 3.

Rice. 1. Copper. Appearance.

Atomic and molecular mass of copper

DEFINITION

Relative molecular weight of the substance(M r) is a number showing how many times the mass of a given molecule is greater than 1/12 the mass of a carbon atom, and relative atomic mass of an element(A r) - how many times the average mass of atoms of a chemical element is greater than 1/12 of the mass of a carbon atom.

Since in the free state chromium exists in the form of monatomic Cu molecules, the values ​​of its atomic and molecular masses coincide. They are equal to 63.546.

Isotopes of copper

It is known that in nature copper can be found in the form of two stable isotopes 63 Cu (69.1%) and 65 Cu (30.9%). Their mass numbers are 63 and 65, respectively. The nucleus of an atom of the copper isotope 63 Cu contains twenty-nine protons and thirty-four neutrons, and the isotope 65 Cu contains the same number of protons and thirty-six neutrons.

There are artificial unstable isotopes of copper with mass numbers from 52 to 80, as well as seven isomeric states of nuclei, among which the longest-lived isotope 67 Cu with a half-life of 62 hours.

Copper ions

The electronic formula demonstrating the orbital distribution of copper electrons is as follows:

1s 2 2s 2 2p 6 3s 2 3p 6 3d 10 4s 1 .

As a result of chemical interaction, copper gives up its valence electrons, i.e. is their donor, and turns into a positively charged ion:

Cu 0 -1e → Cu + ;

Cu 0 -2e → Cu 2+ .

Copper molecule and atom

In the free state, copper exists in the form of monoatomic Cu molecules. Here are some properties characterizing the copper atom and molecule:

Copper alloys

The most important alloys of copper with other metals are brasses (alloys of copper and zinc), copper-nickel alloys and bronze.

Copper-nickel alloys are divided into structural and electrical. Structural stones include cupronickel and nickel silver. Cupronickel contains 20-30% nickel and small amounts of iron and manganese, while nickel silver contains 5-35% nickel and 13-45% zinc. Electrical copper-nickel alloys include constantan (40% nickel, 1.5% manganese), manganin (3% nickel and 12% manganese) and copel (43% nickel and 0.5% manganese).

Bronzes are divided according to the main component in their composition (except copper) into tin, aluminum, silicon, etc.

Examples of problem solving

EXAMPLE 1

EXAMPLE 2

Copper

Copper(lat. Cuprum) is a chemical element of group I of the periodic system of Mendeleev (atomic number 29, atomic mass 63.546). In compounds, copper usually exhibits oxidation states +1 and +2; a few trivalent copper compounds are also known. The most important copper compounds: oxides Cu 2 O, CuO, Cu 2 O 3; hydroxide Cu(OH) 2, nitrate Cu(NO 3) 2. 3H 2 O, CuS sulfide, sulfate (copper sulfate) CuSO 4. 5H 2 O, carbonate CuCO 3 Cu(OH) 2, chloride CuCl 2. 2H2O.

Copper- one of the seven metals known since ancient times. The transition period from the Stone to the Bronze Age (4th - 3rd millennium BC) was called copper age or Chalcolithic(from the Greek chalkos - copper and lithos - stone) or Chalcolithic(from Latin aeneus - copper and Greek lithos - stone). Copper tools appeared during this period. It is known that copper tools were used during the construction of the Cheops pyramid.

Pure copper is a malleable and soft metal of a reddish color, pink when fractured, in places with brown and mottled tarnish, heavy (density 8.93 g/cm3), an excellent conductor of heat and electricity, second in this regard only to silver (melting point 1083 ° C). Copper is easily drawn into wire and rolled into thin sheets, but has relatively little activity. In dry air and oxygen under normal conditions, copper does not oxidize. But it reacts quite easily: already at room temperature with halogens, for example with wet chlorine, it forms CuCl 2 chloride, when heated with sulfur it forms Cu 2 S sulfide, with selenium. But copper does not interact with hydrogen, carbon and nitrogen even at high temperatures. Acids that do not have oxidizing properties do not act on copper, for example, hydrochloric and dilute sulfuric acids. But in the presence of atmospheric oxygen, copper dissolves in these acids to form the corresponding salts: 2Cu + 4HCl + O2 = 2CuCl2 + 2H2O.

In an atmosphere containing CO 2, H 2 O vapors, etc., it becomes covered with patina - a greenish film of basic carbonate (Cu 2 (OH) 2 CO 3)), a toxic substance.

Copper is included in more than 170 minerals, of which only 17 are important for industry, including: bornite (variegated copper ore - Cu 5 FeS 4), chalcopyrite (copper pyrite - CuFeS 2), chalcocite (copper luster - Cu 2 S) , covellite (CuS), malachite (Cu 2 (OH) 2 CO 3). Native copper is also found.

Copper density, specific gravity of copper and other characteristics of copper

Density - 8.93*10 3 kg/m 3 ;
Specific gravity - 8.93 g/cm3;
Specific heat capacity at 20 °C - 0.094 cal/deg;
Melting temperature - 1083 °C;
Specific heat of fusion - 42 cal/g;
Boiling temperature - 2600 °C;
Linear expansion coefficient(at a temperature of about 20 °C) - 16.7 * 10 6 (1/deg);
Coefficient of thermal conductivity - 335kcal/m*hour*deg;
Resistivity at 20 °C - 0.0167 Ohm*mm 2 /m;

Copper elastic moduli and Poisson's ratio

COPPER COMPOUNDS

Copper (I) oxide Cu 2 O 3 and cuprous oxide (I) Cu2O, like other copper (I) compounds, are less stable than copper (II) compounds. Copper (I) oxide, or copper oxide Cu 2 O, occurs in nature as the mineral cuprite. In addition, it can be obtained as a precipitate of red copper(I) oxide by heating a solution of a copper(II) salt and an alkali in the presence of a strong reducing agent.

Copper(II) oxide, or copper oxide, CuO- a black substance found in nature (for example, in the form of the mineral tenerite). It is obtained by calcination of copper (II) hydroxycarbonate (CuOH) 2 CO 3 or copper (II) nitrate Cu(NO 2) 2.
Copper(II) oxide is a good oxidizing agent. Copper (II) hydroxide Cu(OH) 2 precipitates from solutions of copper (II) salts under the action of alkalis in the form of a blue gelatinous mass. Even with low heating, even under water, it decomposes, turning into black copper (II) oxide.
Copper(II) hydroxide is a very weak base. Therefore, solutions of copper (II) salts in most cases have an acidic reaction, and with weak acids copper forms basic salts.

Copper (II) sulfate CuSO 4 in an anhydrous state it is a white powder, which turns blue when absorbing water. Therefore, it is used to detect traces of moisture in organic liquids. An aqueous solution of copper sulfate has a characteristic blue-blue color. This color is characteristic of hydrated 2+ ions, therefore all dilute solutions of copper (II) salts have the same color, unless they contain any colored anions. From aqueous solutions, copper sulfate crystallizes with five molecules of water, forming transparent blue crystals of copper sulfate. Copper sulfate is used for electrolytic coating of metals with copper, for the preparation of mineral paints, and also as a starting material in the preparation of other copper compounds. In agriculture, a diluted solution of copper sulfate is used to spray plants and treat grain before sowing to destroy spores of harmful fungi.

Copper (II) chloride CuCl 2. 2H2O. Forms dark green crystals, easily soluble in water. Very concentrated solutions of copper (II) chloride are green, diluted solutions are blue-blue.

Copper (II) nitrate Cu(NO 3) 2. 3H2O. It is obtained by dissolving copper in nitric acid. When heated, blue copper nitrate crystals first lose water and then easily decompose, releasing oxygen and brown nitrogen dioxide, turning into copper (II) oxide.

Copper (II) hydroxycarbonate (CuOH) 2 CO 3. It occurs naturally in the form of the mineral malachite, which has a beautiful emerald green color. It is artificially prepared by the action of Na 2 CO 3 on solutions of copper (II) salts.
2CuSO 4 + 2Na 2 CO 3 + H 2 O = (CuOH) 2 CO 3 ↓ + 2Na 2 SO 4 + CO 2
It is used for the production of copper (II) chloride, for the preparation of blue and green mineral paints, as well as in pyrotechnics.

Copper (II) acetate Cu (CH 3 COO) 2. H2O. It is obtained by treating copper metal or copper(II) oxide with acetic acid. Usually it is a mixture of basic salts of various compositions and colors (green and blue-green). Under the name verdigris, it is used to prepare oil paint.

Complex copper compounds are formed as a result of the combination of doubly charged copper ions with ammonia molecules.
A variety of mineral paints are obtained from copper salts.
All copper salts are poisonous. Therefore, to avoid the formation of copper salts, copper utensils are coated on the inside with a layer of tin (tinned).

COPPER PRODUCTION

Copper is mined from oxide and sulfide ores. 80% of all mined copper is smelted from sulfide ores. Typically, copper ores contain a lot of gangue. Therefore, a beneficiation process is used to obtain copper. Copper is obtained by smelting it from sulfide ores. The process consists of a number of operations: roasting, smelting, converting, fire and electrolytic refining. During the firing process, most of the impurity sulfides are converted into oxides. Thus, the main impurity of most copper ores, pyrite FeS 2, turns into Fe 2 O 3. The gases produced during roasting contain CO 2, which is used to produce sulfuric acid. The resulting oxides of iron, zinc and other impurities during the firing process are separated in the form of slag during melting. Liquid copper matte (Cu 2 S with an admixture of FeS) enters the converter, where air is blown through it. During conversion, sulfur dioxide is released and crude or raw copper is obtained. To extract valuable (Au, Ag, Te, etc.) and to remove harmful impurities, blister copper is first subjected to fire and then electrolytic refining. During fire refining, liquid copper is saturated with oxygen. In this case, impurities of iron, zinc and cobalt are oxidized, turn into slag and are removed. And copper is poured into molds. The resulting castings serve as anodes during electrolytic refining.
The main component of the solution during electrolytic refining is copper sulfate - the most common and cheapest copper salt. To increase the low electrical conductivity of copper sulfate, sulfuric acid is added to the electrolyte. And to obtain a compact copper deposit, a small amount of additives is introduced into the solution. Metal impurities contained in unrefined (“blank”) copper can be divided into two groups.

1)Fe, Zn, Ni, Co. These metals have significantly more negative electrode potentials than copper. Therefore, they anodicly dissolve together with copper, but are not deposited on the cathode, but accumulate in the electrolyte in the form of sulfates. Therefore, the electrolyte must be replaced periodically.

2)Au, Ag, Pb, Sn. Noble metals (Au, Ag) do not undergo anodic dissolution, but during the process they settle at the anode, forming anode sludge together with other impurities, which is periodically removed. Tin and lead dissolve together with copper, but in the electrolyte they form poorly soluble compounds that precipitate and are also removed.

COPPER ALLOYS

Alloys, which increase the strength and other properties of copper, are obtained by introducing additives into it, such as zinc, tin, silicon, lead, aluminum, manganese, and nickel. More than 30% of copper is used for alloys.

Brass- alloys of copper and zinc (copper from 60 to 90% and zinc from 40 to 10%) - stronger than copper and less susceptible to oxidation. When silicon and lead are added to brass, its anti-friction qualities increase; when tin, aluminum, manganese and nickel are added, its anti-corrosion resistance increases. Sheets and cast products are used in mechanical engineering, especially in chemical, optics and instrument making, and in the production of meshes for the pulp and paper industry.

Bronze. Previously, bronzes were alloys of copper (80-94%) and tin (20-6%). Currently, tin-free bronzes are produced, named after the main component after copper.

Aluminum bronzes contain 5-11% aluminum, have high mechanical properties combined with anti-corrosion resistance.

Lead bronzes, containing 25-33% lead, are used mainly for the manufacture of bearings operating at high pressures and high sliding speeds.

Silicon bronzes, containing 4-5% silicon, are used as cheap substitutes for tin bronzes.

Beryllium bronzes, containing 1.8-2.3% beryllium, are distinguished by hardness after hardening and high elasticity. They are used for the manufacture of springs and spring products.

Cadmium bronzes- copper alloys with a small amount of cadmium (up to 1%) - are used for the manufacture of fittings for water and gas lines and in mechanical engineering.

Solders- alloys of non-ferrous metals used in soldering to obtain a monolithic soldered seam. Among hard solders, copper-silver alloy is known (44.5-45.5% Ag; 29-31% Cu; the rest is zinc).

USES OF COPPER

Copper, its compounds and alloys are widely used in various industries.

In electrical engineering, copper is used in its pure form: in the production of cable products, busbars of bare and contact wires, electric generators, telephone and telegraph equipment and radio equipment. Heat exchangers, vacuum devices, and pipelines are made from copper. More than 30% of copper goes to alloys.

Alloys of copper with other metals are used in mechanical engineering, in the automotive and tractor industries (radiators, bearings), and for the manufacture of chemical equipment.

The high viscosity and ductility of the metal make it possible to use copper for the manufacture of a variety of products with very complex patterns. Red copper wire in the annealed state becomes so soft and flexible that you can easily twist all kinds of cords from it and bend the most complex ornamental elements. In addition, copper wire is easily soldered with hard silver solder and is well silvered and gold-plated. These properties of copper make it an indispensable material in the production of filigree products.

The coefficient of linear and volumetric expansion of copper when heated is approximately the same as that of hot enamels, and therefore, when cooled, the enamel adheres well to the copper product and does not crack or bounce off. Thanks to this, craftsmen prefer copper to all other metals for the production of enamel products.

Like some other metals, copper is one of the vital microelements. She is involved in the process photosynthesis and the absorption of nitrogen by plants, promotes the synthesis of sugar, proteins, starch, and vitamins. Most often, copper is added to the soil in the form of pentahydrate sulfate - copper sulfate CuSO 4. 5H 2 O. In large quantities it is poisonous, like many other copper compounds, especially for lower organisms. In small doses, copper is necessary for all living things.