The first metal mastered by man. The oldest metals of mankind

As you know, the main material from which primitive people made tools was stone. No wonder the hundreds of thousands of years that have passed between the appearance of man on earth and the emergence of the first civilizations are called the Stone Age. But in 5-6 millennia BC. e. people discovered metal.

Most likely, at first, a person treated metal in the same way as a stone. He found, for example, copper nuggets and tried to process them in the same way as a stone, that is, with the help of upholstery, grinding, squeezing flakes, etc. But the difference between stone and copper quickly became clear. Perhaps, even initially, people decided that there would be no sense in metal nuggets, especially since copper was quite soft, and the tools that were made from it quickly failed. Who came up with the idea of ​​melting copper? Now we will never know the answer to this question. Most likely, everything happened by accident. An annoyed person threw a pebble, which seemed to him unsuitable for making an ax or an arrowhead, into the fire, and then was surprised to notice that the pebble spread out in a shiny puddle, and after the fire burned out, it froze. Then it took only a little thought - and the idea of ​​melting was discovered. On the territory of modern Serbia, a copper ax was found, created 5,500 years before the birth of Christ.

True, copper, of course, was inferior in many respects even to stone. As mentioned above, copper is too soft a metal. Its main advantage was fusibility, which made it possible to make a wide variety of objects from copper, but in terms of strength and sharpness, it left much to be desired. Of course, before the discovery, for example, of Zlatoust steel (Article "Russian Bulat from Zlatoust"), several more millennia should have passed. After all, technologies were created gradually, at first - insecure, timid steps, by trial and countless mistakes. Copper was soon replaced by bronze, an alloy of copper and tin. True, tin, unlike copper, is not found everywhere. It is not for nothing that in ancient times Britain was called the "Tin Islands" - many peoples equipped trading expeditions there for tin.

Copper and bronze became the basis of ancient Greek civilization. In the Iliad and the Odyssey we constantly read that the Greeks and Trojans were dressed in copper and bronze armor and used bronze weapons. Yes, in ancient times, metallurgy largely served the military. They often plowed the land in the old fashioned way, with a wooden plow, and, for example, drains could be made of wood or clay, but the fighters entered the battlefield in strong metal armor. However, bronze as a material for weapons had one serious drawback: it was too heavy. Therefore, over time, a person learned to smelt and process steel.

Iron has been known since the Bronze Age on Earth. However, raw iron, obtained as a result of processing at a low temperature, was too soft. Meteoritic iron was more popular, but it was very rare, it could only be found by chance. However, meteoritic iron weapons were expensive, and it was very prestigious to have them. The Egyptians called daggers forged from meteorites that fell from the sky Heavenly.

It is generally accepted that iron processing was widespread among the Hittites living in the Middle East. They are about 1200 BC. e. learned to smelt real steel. For a while, Middle Eastern powers became incredibly powerful, the Hittites defied Rome itself, and the Philistines, mentioned in the Bible, owned vast territories in the modern Arabian Peninsula. But soon their technological advantage faded, because steelmaking technology, as it turned out, was not so difficult to borrow. The main problem was the creation of furnaces in which it was possible to reach the temperature at which iron turned into steel. When the neighboring peoples learned to build such melting furnaces, steel production began literally throughout Europe. Of course, much depended on raw materials. After all, only relatively recently people have learned to enrich the raw materials with additional substances that give steel new properties. For example, the Romans mocked the Celts, because many of the Celtic tribes had such bad steel that their swords bent in battle, and the warriors had to run back to the back row to straighten the blade. But the Romans bowed before the products of gunsmiths from India. And among some Celtic tribes, steel was not inferior to the famous Damascus. (Article "Damascus steel: myths and reality")

But, in any case, humanity entered the Iron Age, and it could no longer be stopped. Even the widest spread of plastics that occurred in the twentieth century could not displace metal from most areas of human activity.

Student Supplement #2

on the topic "Minerals and alloys in the design

Station "Revolution Square"

Moscow Metro"

Copper is the first metal mastered by man

The role of copper in the development of human culture is special. The use of copper and bronze as the most important materials lasted for millennia. Copper, like noble metals, sometimes forms nuggets. Scientists believe that it was from them that the first metal tools were made 10 thousand years ago. Due to the softness and rather widespread occurrence of copper in nature, man began to use it long before iron.

Historians have established that in ancient Egypt, when building pyramids, artisans used stone tools (made of granite and dolerite) and copper tools. The metal was remarkably hard. This allowed Egyptologists to suggest that already in the III millennium BC. e. The Egyptians had some special recipe for mechanical processing of copper, which gave the metal high strength.

The addition of tin to copper significantly increases the strength and hardness of the material. This was known as early as 5000 years ago, and possibly even earlier. The production of copper alloys was greatest achievement ancient metallurgy and gave the name to an entire era - the Bronze Age.

The change of epochs among different peoples, in different parts of the globe took place unevenly, and the chronological framework of the epochs can only be indicated approximately:

STONE → COPPER AGE → BRONZE → IRON
AGE (chalcolith) AGE AGE

4th-3rd millennium 4th-1st millennium beginning of the 1st millennium

BC e. BC e. BC e.

The spread of bronze in the advanced cultural centers of metallurgy began at the end of the 4th millennium BC. e. The oldest bronze items were found on the territory of Mesopotamia (in Sumer), Turkey, Iran. At the end of the third millennium BC. e. bronze appeared in Egypt, India, and in the middle of the II millennium BC. e. in China and Europe. In America, the Bronze Age, the Bronze Age covers the period from the 4th to the 10th centuries. n. e. The leading metallurgical centers here were located on the territory of modern Peru and Bolivia.

In addition to bronzes - copper-tin alloys, the ancients also used copper-zinc alloys - brass, which are stronger and more malleable than bronze. It is noteworthy that people of ancient times were not familiar with zinc as a substance. In its pure form, this metal was isolated only in the middle of the 18th century by electrolysis. So, during excavations in Thebes, papyri were found, which describe the secret of making "gold" from copper. In fact, they are, in all likelihood, about obtaining brass by adding natural zinc compounds to copper. Brass resembles gold in its color and brilliance.

Methods for obtaining copper

The low chemical activity of copper makes it possible for it to exist in nature in its native state.

More than 200 minerals are known that contain copper in their composition, including chalcopyrite (copper pyrite) CuFeS2, malachite (CuOH) 2CO3, chalcocite (copper luster) Cu2S, cuprite Cu2O.

Get pure copper various methods. Hydrometallurgical method - extraction of metals from ores using reagents (H2SO4, KCN, etc.) in the form of compounds soluble in water, followed by processing of these solutions to isolate metals in a free form.

When ore containing CuO is treated with dilute sulfuric acid, copper goes into solution in the form of sulfate:

CuO + H2SO4 = CuSO4 + H2O

Then it is removed from the solution either by electrolysis or displaced from sulfate with iron:

CuSO4 + Fe = Cu + FeSO4

All methods of obtaining copper from compounds are based on redox processes.

Chemical properties of copper

In dry form and at normal temperature, copper almost does not change. At elevated temperatures, copper can react with simple and complex substances.

Interaction with simple substances:

Cu + Cl2 = CuCl2

2CuO + O2 = 2CuO

Interaction with complex substances:

Cu + 2H2SO4 = CuSO4 + SO2 + 2H2O

Cu + 4HNO3 = Cu(NO)3 + 2NO2 + 2H2O

Copper and its alloys

Copper has a melting point of 1083oC.

There are two groups of copper alloys: brass– copper-zinc alloys, bronze- alloys of copper with other (except zinc) elements.

Aluminum "href="/text/category/aluminij/" rel="bookmark">aluminum, Mn - manganese, C - lead, B - beryllium, Mg - magnesium, Cp - silver, F - iron, Msh - arsenic, Su - antimony, K - silicon, H - nickel, T - titanium, Kd - cadmium, O - tin, F - phosphorus, X - chromium, C - zinc .

All bronze is marked with the abbreviation "Br", indicating this category of copper alloys. After designating the class of copper alloy "Br" come letters to help identify the added elements.

For example, BrO5Ts6 means that this bronze alloy contains 5% tin and 6% zinc, and the designation BrO5Ts2N5 indicates that the alloy includes 5% tin, 2% zinc and 5% nickel. The BrO10Ts2 marking identifies a bronze alloy containing 10% tin and 2% zinc.

At the Leningrad state copper-working plant "Krasny Vyborzhets" (1924), the so-called artistic red bronze with a zinc additive not exceeding 6% was used for casting. Red bronze is not sensitive to temperature changes.

But the projects at the plant were cast 80 sculptural figures for the station "Revolution Square" of the Moscow Metro.

Varieties of marbles in the design of metro stations

Each metro station is like a mineralogical museum, each of them has its own exposition.

The basement of the Ploshchad Revolyutsii metro station is lined with black Armenian marble-like limestone with “golden” veins, which has turned into a huge pedestal, and the arches are made of dark red marble-like limestone shrosha. The arches were built from solid stones carved from marble blocks. The walls of the pylons are lined with red shrosha, gray-blue ufaley, yellow-pink marble-like biyuk-yanka limestone. The track walls of the station were decorated with gray Ufaley marble, with a cornice made of red shrosha, and a plinth-carpet mosaic of olive-black marble-like sadakhlo and dalu limestones. The floor of the station hall is a checkerboard alternation of dark gray Zhezhelevsky granite and black gabbro, and the platforms are finished with the same granite and labranite.

On the walls of the platforms are fixed bronze arrows with the inscriptions "Exit to the city" - these are the oldest surviving signs of the Moscow metro.

The following types of marbles are most common in construction practice:

Ufaleysky(Ufaley), gray-blue.

Marbles of Georgia. Shroshinsky (Shrosha), dark red with white streaks.

Sadakhlinsky(Sadakhlo), dark black with white and yellowish-golden streaks.

Marbles of Armenia. Davalinsky (Davalu), black with golden streaks. This marble is usually used in combination with marbles of other colors for pedestals and plinths of marble cladding.

Like gold and silver, copper is sometimes found in the earth's crust in the form of nuggets. It is possible that the first metal tools were made from them about 10 thousand years ago. The spread of copper was facilitated by its properties such as the ability to cold forging and ease of smelting from rich ores. In Cyprus, already in the 3rd millennium BC, there were copper mines and copper smelting was carried out. From here comes the Latin name for copper - suprum. On the territory of Russia, copper mines appeared two millennia BC. e. Their remains are found in the Urals, the Caucasus, Siberia. In the writings of the ancient Greek historian Strabo, copper is called chalkos, from the name of the city of Chalkis. Many terms in geochemistry and mineralogy originated from this word, for example, chalcophile elements, chalcopyrite. Russian word copper is found in the most ancient literary monuments and does not have a clear etymology. Some researchers refer the origin of the term to the name of the ancient state of Media, located on the territory of modern Iran.

The simple substance copper is a ductile metal of a golden-pink color. In the Periodic Table, it occupies cell No. 29 (symbol Cu) with an atomic mass of 63.55 a.m.u.

Chalcopyrite crystal 4x5x4 cm. Nikolayevsky mine, Primorsky Krai.

According to data for 2016, Chile is the world leader in copper reserves with a share of 34%, the second and third places are shared by the USA and Peru - 9% each, Australia is fourth - 6%, fifth - Russia with a share of 5%. Other countries less than 5%.

Reserves of copper ores for 2016

Chile is the largest copper producing country. On its territory is the world's largest copper deposit Chuquicamata (Spanish: Chuquicamata) where copper ore is mined open way since 1915. The quarry is located in the central Andes at an altitude of 2840 m and is currently the largest quarry in the world: length - 4.3 km, width - 3 km, depth - 850 m.

Chuquicamata Quarry, Chile.

Copper is widely used in electrical engineering for the manufacture of power and other cables, wires and other conductors. In 2011, the cost of copper was about $9,000 per ton. Due to the global economic crisis, the price of most types of raw materials fell, and the cost of 1 ton of copper in 2016 did not exceed $4,700.

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For many thousands of years, stone products have been the main tools used by man. The craftsmen who processed the stone, like a sculptor, guessed a new quality in it and, cutting off the excess, produced required item. However, ancient man, in essence, only reproduced natural processes, destroying rocks.

The design of products, which has been mastered for several thousand years, required the development of spatial thinking and the development of fundamentally new skills in the manufacture of composite, from several parts and connecting elements, tools. But in this case, before the eyes of the master was the source material natural origin. Even in the process of mastering the production of ceramics, the natural processes of firing clay in a fire flame were imitated. The manufacture of products from ore metal is a revolutionary technology, a technology that could not be “peeped” in nature! This is the first fully artificial technology in the history of civilization. How did a person learn to receive and process metals? Consider a modern version of this amazing process.

What do the lobster shell and the "supersteel" of the near future have in common? Scientists have found that the chitinous base of the shell, consisting of carbon, hydrogen and nitrogen, is a honeycomb structure of polymer crystals with dimensions of the order of a nanometer, the free space of which is filled with protein. This allows the material to both float in water and have a strength higher than many grades of special purpose steel. It remains to study and apply natural technology on practice. So, the analysis of natural processes and structures is the key to success. innovative technologies XXI century. However, man has learned to master this key in ancient times, and the development of metallurgical technologies is a clear example of this.

native metals

Neolithic civilization was preceded by a long formation and slow development of tools and tools used by man. The history of primitive human society was inextricably linked with stone. The most primitive stone products were ordinary river pebbles, chipped at one end. The age of the oldest stone tools dates back to a period of about 2.5 million years. major event was the development of flint tools.

In flint, for the first time, the form of such fundamental for technical progress items like axe, sickle, knife, hammer. The use of native metals most likely began in the Mesolithic (Middle Stone Age), i.e. several tens of thousands of years ago. By this time, the skill of finding, extracting stones and making them not only tools, but also jewelry for primitive man had become commonplace and turned into a kind of industry.

It was in the process of searching for stones suitable for the manufacture of new products that people drew attention to the first nuggets of metals, apparently copper, which are much more common in nature than nuggets of precious metals - gold, silver, platinum. Native (telluric, from the Latin word "tellus" - earth) copper is still found today in many regions of the world: in Asia Minor, Indochina, Altai, and America. Until now, there are copper nuggets weighing several kilograms. The largest manifestation of native copper is considered to be a continuous copper vein found on the Kyusinou Peninsula (Lake Superior, USA). Its mass is estimated at about 500 tons.

Not only noble metals can be present in native form under terrestrial conditions. It is known that nuggets of iron, mercury and lead are found in nature, much less often - nuggets of such metals and alloys as zinc, aluminum, brass, cast iron. They are found in the form of small leaves and scales interspersed in rocks, most often in basalt. In the 20th century, native iron was found, for example, on Disko Island off the coast of Greenland, in Germany (near the city of Kassel), in France (Auvergne department), in the USA (Connecticut). It always contains a significant amount of nickel, impurities of cobalt, copper and platinum (from 0.1 to 0.5% by weight of each element) and, as a rule, is very poor in carbon. Finds of native cast iron are known, for example, on the Russky Islands (on Far East) and Borneo, as well as in Crash Bay (New Zealand), where the native alloy was represented by cohenite - iron-nickel-cobalt carbide (Fe, Ni, Co)3C.

Observation of the change in the shape of nuggets under the blows of hard stones prompted a person to use them for making small jewelry by cold forging. Forging is the oldest method of working metals by pressure. Mastering the method of processing native metal by forging was based on the skills and experience of making stone tools by “upholstering” the stone with a stone hammer. Native copper, which primitive people at first also considered a kind of stone, when struck by a stone hammer, did not give chips characteristic of stone, but changed its size and shape without disturbing the continuity of the material. This remarkable technological property of the "new stone" has become a powerful incentive for the search and extraction of native metal and its use by man. In addition, it has been observed that forging increases the hardness and strength of the metal.

At first, ordinary pieces of hard stone were used as a hammer. A primitive craftsman, holding a stone in his hand, struck them at a piece of native, and later - smelted from ore metal. The evolution of this simplest forging method led to the creation of a prototype blacksmith's hammer equipped with a handle. However, metal processing by cold forging had limited possibilities. In this way, it was possible to shape only small objects - a pin, a hook, an arrowhead, an awl. Later, the technology of forging copper nuggets with preheating - annealing was mastered.

Gold nuggets, a metal much more ductile than copper, provided great opportunities for the development of the first metalworking technologies. Gold played an outstanding role in the development of mining metallurgical production civilization. Placer deposits were the first gold-bearing deposits developed by man. Gold nuggets were found in the mass of alluvial sands and gravels, which were the products of the destruction of gold-bearing rocks, which were exposed to river flows for a long time. Apparently, the oldest jewelry made of gold were nuggets processed in the form of beads by cold forging. These polished beads looked like colored stones strung together in various combinations.

During the extraction of gold from veins, technologies were created, which were then used in the development of deposits of other ancient metals. Gold became the first metal from which they learned to cast products, get wire and foil, gold was first refined. Essentially, all metallurgical technologies used in the era ancient world to silver, copper, lead, tin, were originally worked out on gold.

However, the basis of civilization until the 3rd millennium BC. e. the stone remained. characteristic feature early Neolithic technology was the transition to large stone tools. Their appearance is associated with the development of new technological methods of stone processing - drilling, sawing, grinding. Composite ("liner") tools were invented, in which stone material was used only for the working part, and the handles were made of wood, horn or bone. Gradually, the repair of tools was developed - their correction as the working part wears out. Mining arose, in which fire was used to destroy rocks. An amazing technical achievement of people of the Neolithic era is the extraction of flints in mines with a vertical shaft up to 10 m deep and short drifts. Thus, at the beginning of the Neolithic revolution, people had a variety of knowledge about natural substances and materials, methods for their processing.

Thermal technologies of the Neolithic

The most important distinguishing feature of a productive Neolithic economy is the creation of a food supply. When solving the problem of making dishes for its storage, ceramic products are invented and gradually develop thermal technologies. The first pottery items were baskets made of twigs coated with clay and fired at the stake. Then special kilns for firing were created - forges.

Neolithic stove adapted for natural draft

Modern reconstructions reproduce the Neolithic method of firing pottery as follows. The horn was built in the steep bank of the river, in the walls of ravines or hills, and consisted of two branches. The horizontal sleeve served as a firebox, and the vertical one was filled with pots. When the forge was filled with pre-dried pots, the top of the forge was covered with scrap pottery and a low fire was built using raw wood. Such a fire was maintained until the separation of vapors ceased, after which the fire was increased to a red heat. The pots were in this fire for at least 6 hours. Then the top of the hearth was covered with sand, the firebox was covered with clay and the unit was left in this state for several days. After that, a hole was made in the firebox and gradually enlarged. Finally, the top of the hearth was opened and the finished pots were taken out. Such ancient kilns for firing ceramics were found in Mesopotamia, North Africa, and Eastern Europe. The heating temperature of products in them reached 1100 °C.

To master the metallurgical technology of extracting metal from ore, which requires reliable provision of high temperatures, a furnace with artificial blast was needed. For the first time such furnaces were created for pottery production. Thus, a person got acquainted with the ore metal during the firing of clay pots. There was a process of metal recovery from substances deposited on the walls of pottery for their coloring. It is known that copper carbonates - malachite and lapis lazuli, mercury sulfide - cinnabar, yellow, red and brown iron ocher are bright mineral paints, and applying color patterns to ceramics is one of the oldest art forms.

The process of gradual development of new metals and materials by civilization

The first ore metal mastered by man was copper. This happened, apparently, about 10 thousand years ago. Pins, awls, drills, beads, rings and pendants found in the settlements of Chaionu Tepesi and Chatal Huyuk, which are located on the Konya plateau in Turkey, are currently considered the oldest products from ore copper. These finds date back to the 8th-7th millennium BC. e.

Beginning of the era of metals

The real era of metals began in Eurasia in the 5th millennium BC. e. It is characterized by rarities found in the north of the Balkan Peninsula and in the Carpathian region. In archeology, these territories are usually attributed to the most important Balkan-Carpathian metallurgical province of the Copper-Stone Age.

In the early 70s of the last century, incredibly rich and expressive monuments were discovered there: the Varna “golden” necropolis and the huge Aibunar mine, where, according to calculations, at least 30 thousand tons of copper ore were mined. More than 3 thousand various gold and about 100 copper items were found in the Varna burials. Particular attention is drawn to gold jewelry and objects decorated with complex ornaments, however, massive copper tools, tools and weapons are of no less interest to specialists.

The gold and copper of the Balkan-Carpathian metallurgical province posed an unexpected problem for researchers of ancient metal: what were the general efforts of this metallurgical production aimed at? For casting and forging metal tools in order to increase productivity, as described in most well-known textbooks, or for something else? Calculations of archaeologists have shown that already from the first steps of mining and smelting production, the vast majority of its energy was directed to the creation of those products that served the symbolic spheres. public life, - decorations, attributes of power and ritual objects. A giant piece of metal served as a kind of evidence social significance dead. Thus, for several millennia, metals performed mainly a social, and not a production function.

In the 5th millennium BC. e. in most of the territory of Eurasia, oxidized copper ores were actively developed, the veins of which came to the surface. Mining workings were narrow cracks that were formed as a result of excavation of the rock of ore-bearing veins. If a miner came across a powerful ore lens, the gap turned into a cavity at the mining site. The oldest copper mines have been found in Mesopotamia, Spain and the Balkan Peninsula. In the era of antiquity, one of largest deposits Copper became the island of Cyprus, from its late Latin name "cuprum" came the modern name of copper as a chemical element. The Russian name for the metal comes from the ancient Slavic word "smida", which meant metal in general. Note that the term "smida" goes back to those ancient times when the ancestors of the Slavs and Germans were still a single Indo-Aryan people. Subsequently, in the Germanic languages, the term "smida" began to be used to refer to a person working with metal, and was fixed in the form "smith" (English) or "schmidt" (German) - "blacksmith".

The development of underground ore deposits was mastered in the 4th millennium BC. e. The depth of mine workings reached 30 m or more. Fire, water and wooden wedges were used to crush the rock. A fire was lit near the developed site, the rock was heated, and then quickly cooled, pouring abundant water. Wooden wedges were driven into the formed cracks, which were also poured with water. Swelling, the wedges split rock. Fragments of ore rock were again heated in the flame of a fire, cooled sharply and crushed with hammers and picks directly in the mines. Crushed ore was taken from the mines in leather bags or wicker baskets. Then it was pounded in large stone mortars to the size of a pea. Ancient metallurgists used charcoal, dense woods, and bones as fuel for smelting metal.

The most ancient method of processing copper ore is crucible smelting: the ore was mixed with fuel and placed in crucibles made of clay mixed with bone ash. The dimensions of the crucibles were small, their height was 12–15 cm, and holes were provided in the lid for the release of gases. In the pottery hearths of the Neolithic times described above, a temperature (up to 1100 ° C) was reached, sufficient to obtain copper containing up to 2% wt. natural impurities of arsenic, nickel, antimony. Subsequently, for the smelting of copper, pit furnaces began to be arranged. In this case, a clay crucible with ore and coal was placed in a shallow pit with a layer of charcoal poured over it. Of particular importance was the choice of the place of melting, which was supposed to provide an intensive flow of air into the unit to fan the fire and achieve the required temperature.

The amount of copper produced in crucibles was small and, as a rule, amounted to several tens of grams, so they gradually switched to the production of copper in pits directly from the ore. To do this, copper ore mixed with charcoal was placed in pits up to 30 cm deep, the bottom of which was lined with stones. A certain amount of charcoal was poured over the charge layer, and tree branches and a small amount of earth were placed on top in such a way as not to impede the flow of air into the heap. They tried to place the smelting place on the slopes of hills in order to use the natural movement of air. This was the first "industrial" metallurgical unit.

Upon completion of the smelting, unburned fuel was removed, and the resulting metal was crushed into pieces convenient for use. This was done immediately after the solidification of the metal, since at this stage copper is especially brittle and easily broken into pieces with a hammer. To give raw copper a marketable appearance, it was subjected to cold forging. Very early it was discovered that copper is a soft and malleable metal, easily compacted and freed from coarse inclusions with the simplest mechanical processing.

With many advantages, copper, even naturally alloyed, had a very significant drawback: copper tools quickly became dull. The wear resistance and other properties of copper were not so high that copper tools and tools could completely replace stone ones. Therefore, throughout the Copper-Stone Age (4th millennium BC), stone successfully competed with copper, which was reflected in the name of the era. The decisive step in the transition from stone to metal was made after the invention of bronze.