Mastering Metals. The oldest metals of mankind Varieties of marble in the design of metro stations

“Seven metals created light according to the number of seven planets” - one of the most important postulates of medieval alchemy was concluded in these simple rhymes. In ancient times and in the Middle Ages, only seven metals and the same number of celestial bodies (the Sun, the Moon and five planets, not counting the Earth) were known. In the opinion of the luminaries of science of that time, only fools and ignoramuses could not see in this the deepest philosophical regularity. A slender alchemical theory said that gold is represented in the heavens by the Sun, silver is a typical Moon, copper is undoubtedly related by kinship with Venus, iron is personified by Mars, mercury corresponds to Mercury, tin to Jupiter, lead to Saturn. Until the 17th century, metals were designated in literature by the corresponding symbols.

Figure 1 - Alchemical signs of metals and planets

More than 80 metals are currently known, most of which are used in technology.

Since 1814, at the suggestion of the Swedish chemist Berzelius, letter signs have been used to designate metals.

The first metal that a person learned to work was gold. The most ancient things made of this metal were made in Egypt about 8 thousand years ago. In Europe 6 thousand years ago the Thracians, who lived on the territory from the Danube to the Dnieper, were the first to make jewelry and weapons from gold and bronze.

Historians distinguish three stages in the development of mankind: the Stone Age, the Bronze Age and the Iron Age.

In the 3rd millennium BC. people began to widely use metals in their economic activities. The transition from stone to metal tools was of colossal importance in the history of mankind. Perhaps no other discovery has led to such significant social changes.

The first metal to become widespread was copper (Figure 2).

Figure 2 - Map-diagram of the territorial-chronological distribution of metals in Eurasia and North Africa

The map clearly shows the location of the oldest finds of metal products. Almost all known artifacts dating back to the period from the end of the 9th to the 6th millennium BC. (that is, before the Uruk-type culture spread widely in Mesopotamia), originate from only three dozen sites scattered over a vast territory of 1 million km 2. About 230 small samples were recovered from here, and 2/3 of them belong to two settlements of the pre-ceramic Neolithic - Chaionu and Ashikli.

Constantly looking for the stones they needed, our ancestors, one must think, already in ancient times drew attention to reddish-green or greenish-gray pieces of native copper. In the cliffs of the banks and rocks, they came across copper pyrite, copper luster and red copper ore (cuprite). At first, people used them as ordinary stones and processed them accordingly. They soon discovered that when the copper was hammered with a stone hammer, its hardness increased significantly and it became suitable for making tools. Thus, the methods of cold metal working or primitive forging came into use.

Then another important discovery was made - a piece of native copper or surface rock containing metal, falling into the fire of a fire, discovered new features that were not characteristic of a stone: from strong heating, the metal melted and, cooling down, took on a new shape. If the form was made artificially, then a product necessary for a person was obtained. Ancient craftsmen used this property of copper first for casting jewelry, and then for the production of copper tools. This is how metallurgy was born. Smelting began to be carried out in special high-temperature furnaces, which were a slightly modified design of pottery furnaces well known to people (Figure 3).

Picture 3 - Smelting of metal in Ancient Egypt (blowing is supplied by furs, sewn from animal skins)

In Southeastern Anatolia, archaeologists have discovered a very ancient pre-pottery Neolithic settlement, Chaionu Tepesi (Figure 4), which was struck by the unexpected complexity of stone architecture. Scientists have found among the ruins about a hundred small pieces of copper, as well as many fragments of a copper mineral - malachite, some of which have been processed into beads.

Figure 4 - Settlement of Chaionu Tepesi in Eastern Anatolia: IX-VIII millennium BC The oldest metal on the planet was discovered here

Generally speaking, copper is a soft metal, much inferior in hardness to stone. But the brass tools could be sharpened quickly and easily. (According to S.A. Semenov's observations, when replacing a stone ax with a copper one, the cutting speed increased approximately threefold.) The demand for metal tools began to grow rapidly.

People began a real "hunt" for copper ore. It turned out that it is not found everywhere. In those places where rich copper deposits were found, their intensive development occurred, ore and mining operations appeared. As the discoveries of archaeologists show, in ancient times the process of ore mining was set up on a large scale. For example, near Salzburg, where copper mining began around 1600 BC, the mines reached a depth of 100 m, and the total length of drifts extending from each mine was several kilometers.

The ancient miners had to solve all the problems that modern miners face: strengthening the vaults, ventilation, lighting, climbing a mountain of mined ore. The adits were reinforced with wooden supports. The mined ore was smelted nearby in low clay kilns with thick walls. Similar centers of metallurgy existed in other places (Figures 5 and 6).

Figure 5 - Ancient mines

Figure 6 - Tools of ancient miners

At the end of the 3rd millennium BC. ancient craftsmen began to use the properties of alloys, the first of which was bronze. The discovery of bronze should have been prompted by an accident inevitable in the mass production of copper. Some grades of copper ores contain insignificant (up to 2%) tin impurities. When smelting such ore, the craftsmen noticed that the copper obtained from it is much harder than usual. Tin ore could have entered the copper smelting furnaces for another reason. Be that as it may, observations of the properties of ores led to the development of the value of tin, which they began to add to copper, forming an artificial alloy - bronze. When heated with tin, copper melted better and was easier to cast, as it became more fluid. Bronze tools were harder than copper ones, and sharpened well and easily. The metallurgy of bronze has made it possible to increase labor productivity in all branches of human activity by several times (Figure 7).

The very production of tools has become much easier: instead of long and hard work hammering and grinding the stone, people filled the finished forms with liquid metal and received results that their predecessors had never dreamed of even in a dream. The casting technique was gradually improved. At first, casting was carried out in open clay or sand molds, which were simply a depression. They were replaced by open forms carved out of stone that could be reused. However, the big disadvantage of open molds was that they only produced flat products. They were not suitable for casting complex shapes. The solution was found when closed detachable forms were invented. Before casting, the two halves of the mold were firmly connected to each other. Then molten bronze was poured through the hole. When the metal cooled down and hardened, the mold was disassembled and a finished product was obtained.

Figure 7 - Bronze tools

This method made it possible to cast products of complex shapes, but it was not suitable for shaped casting. But even this difficulty was overcome when the closed form was invented. With this casting method, an exact model of the future product was first molded from wax. Then it was coated with clay and fired in an oven.

The wax melted and evaporated, and the clay took on an accurate cast of the model. Bronze was poured into the void thus formed. When it cooled down, the mold was broken. Thanks to all these operations, craftsmen were able to cast even hollow objects of very complex shapes. Gradually, new techniques for working with metals were discovered, such as drawing, riveting, brazing and welding, complementing the already known forging and casting (Figure 8).

Figure 8 - Golden Hat of the Celtic Priest

Perhaps the largest metal casting was made by Japanese craftsmen. It was 1200 years ago. It weighs 437 tons and represents the Buddha in a pose of peace. The height of the sculpture together with the pedestal is 22 m. The length of one arm is 5 m. Four people could dance freely on an open palm. We add that the famous ancient Greek statue - the Colossus of Rhodes - 36 m high and weighed 12 tons. It was cast in the III century. BC e.

With the development of metallurgy, bronze products began to displace stone ones everywhere. But one shouldn't think that it happened very quickly. Non-ferrous metal ores were not found everywhere. Moreover, tin was found much less frequently than copper. Metals had to be transported over long distances. The cost of metal tools remained high. All this prevented their wide distribution. Bronze could not completely replace stone tools. Only the hardware could do it.

In addition to copper and bronze, other metals were also widely used.

Beads and pendants found in Asia Minor during the excavations of Chatal-Huyuk and seals and figurines found in Yarim-Tepe (Northern Mesopotamia) are considered to be the most ancient lead products. These findings date back to the 6th millennium BC. The first iron rarities, which are small krytsy found in Chatal Huyuk, date back to the same time. The oldest silver items were found in Iran and Anatolia. In Iran, they were found in the town of Tepe-Sialk: these are buttons dating from the beginning of the 5th millennium BC. In Anatolia, in Beyjesultan, a silver ring was found dating from the end of the same millennium.

In prehistoric times, gold was obtained from placers by washing. It came out in the form of sand and nuggets. Then they began to use gold refining (removal of impurities, separation of silver), in the second half of the 2nd millennium BC. In the 13-14 centuries, they learned to use nitric acid to separate gold and silver. And in the 19th century, the amalgamation process was developed (although it was known in antiquity, there is no evidence that it was used to extract gold from sands and ores).

Silver was mined from galena, along with lead. Then, centuries later, they began to be smelted together (by about the 3rd millennium BC in Asia Minor), and this became widespread even after 1500-2000 years.

Around 640 BC e. began to mint coins in Asia Minor, and around 575 BC. e. - in Athens. In fact, this is the beginning of stamping production.

Tin was once smelted long ago in simple shaft furnaces, after which it was purified by special oxidizing processes. Now in metallurgy, tin is obtained by processing ores according to complex integrated schemes.

Well, mercury was produced by roasting ore in heaps, in which it condensed on cold objects. Then ceramic vessels (retorts) appeared, which were replaced by iron ones. And with the growing demand for mercury, they began to receive it in special furnaces.

Iron was known in China as early as 2357 BC. e., and in Egypt - in 2800 BC. e., although as early as 1600 BC. e. iron was looked upon as a curiosity. The "Iron Age" in Europe began around 1000 BC. e., when the art of smelting iron penetrated the states of the Mediterranean from the Scythians of the Black Sea region.

The use of iron began much earlier than its production. Sometimes they found pieces of grayish-black metal, which, forged into a dagger or a spearhead, gave a weapon more durable and ductile than bronze, and held a sharp blade longer. The difficulty was that this metal was found only by accident. Now we can say that it was meteoric iron. Since iron meteorites are an iron-nickel alloy, it can be assumed that the quality of individual unique daggers, for example, could compete with modern consumer goods. However, the same uniqueness led to the fact that such weapons were not on the battlefield, but in the treasury of the next ruler.

Iron tools have drastically expanded the practical possibilities of man. It became possible, for example, to build houses chopped from logs - after all, an iron ax felled a tree not three times, like a copper one, but 10 times faster than a stone one. Construction of cut stone is also widespread. Naturally, it was also used in the Bronze Age, but the high consumption of a relatively soft and expensive metal decidedly limited such experiments. The possibilities of farmers have also expanded significantly.

For the first time people of Anatolia learned how to process iron. The ancient Greek tradition considered the Khalib people to be the discoverer of iron, for whom the constant expression “father of iron” was used in the literature, and the very name of the people comes precisely from the Greek word Χ? Λυβας (“iron”).

The “Iron Revolution” began at the turn of the 1st millennium BC. e. in Assyria. From the VIII century BC. e welded iron quickly spread in Europe, in the 3rd century BC. e. displaced bronze in Gaul, in the II century AD it appeared in Germany, and in the VI century AD it was already widely used in Scandinavia and in the tribes living in the territory of the future Russia. In Japan, the Iron Age did not come until the 8th century AD.

Initially, only small quantities of iron were received, and over several centuries it sometimes cost forty times more than silver. The iron trade restored the prosperity of Assyria. The way was opened for new conquests (Figure 9).

Picture 9 - Furnace for smelting iron in the ancient Persians

Metallurgists were able to see iron as liquid only in the 19th century, however, even at the dawn of iron metallurgy - at the beginning of the 1st millennium BC - Indian craftsmen were able to solve the problem of obtaining elastic steel without melting iron. This steel was called damask steel, but due to the complexity of manufacturing and the lack of necessary materials in most of the world, this steel remained an Indian secret for a long time.

A more technologically advanced way of obtaining elastic steel, which did not require either highly pure ore, graphite, or special furnaces, was found in China in the 2nd century AD. Steel was reforged many times, folding the workpiece in half with each forging, resulting in an excellent weapon material, called Damascus, from which, in particular, the famous Japanese katanas were made.

As indicated in the previous chapter, individual copper crafts (mainly jewelry) appeared very early. At present, archeology cannot indicate exactly where they first began to smelt ores or where bronze was first obtained - an alloy of copper with other metals. In all likelihood, people first used copper of native origin, which was processed as a special type of stone with plastic properties. But when it was discovered that pieces of copper ore began to melt when heated strongly, and when cooled, they became solid again, the process of metal smelting was discovered. The new property of copper began to be used to create tools with a pre-planned shape, that is, the casting process was invented.

With the development of copper smelting, interest in it increased as a new material for the manufacture of tools, and not just jewelry. However, native copper is rarely found on the surface of the earth. In the V millennium BC. e. began to develop oxidized copper ores, the veins of which came to the surface. The development of sulphide ores dates back to a later time. The workings were narrow slots that were formed as a result of the excavation of ore-bearing veins. If a miner stumbled upon a powerful ore lens, the gap would turn into a cavity at the mine site. In the IV millennium BC. e. began to move to the development of underground deposits. On the Balkan Peninsula, for example, mine workings reached a depth of 27 m. To break off pieces of ore, it was necessary to first warm up the rock, then pour water over it. The result was cracks, into which wooden wedges soaked in water were inserted. When swelling, the wooden wedges tore the ores to pieces. In the workings of the Balkan Peninsula, socketed wedges-kaila made of antler were found. It is believed that miners used them to extract copper ore from veins.

The ore dressing process took place close to the mining. At first, the dry method of beneficiation was known: the mined ore was separated from the waste rock and crushed with stone hammers. Later, the wet enrichment process was used. The crushed ore was placed in wooden trays filled with water. The trays were shaken, as a result pieces of ore, as heavier ones, settled to the bottom, and lighter waste rock floated upward. It was raked up, and pieces of copper ore remained in the tray. Sulfide copper ores were burned on fires for a long time before smelting.

Ore was also smelted not far from mining in special clay kilns. To obtain a higher temperature in the oven, people blew air through the blower tubes. In the III millennium BC. e. leather blowing furs were invented. Ingots of metal smelted from copper ores served as an object of exchange; as a rule, metallurgists were not engaged in jewelry and blacksmithing.

In the V millennium BC. e. the person got acquainted with other non-ferrous metals: silver and gold.

The first alloy, as the researchers suggest, was billon - an alloy of copper and silver. From it in southern Turkmenistan at the turn of the V-IV millennium BC. e. forged jewelry (pins). The alloy of copper with arsenic became known in the 4th millennium BC. e. Arsenic alloys appear in Transcaucasia a thousand years earlier than the tin bronzes of Western Europe. From the III millennium BC e. in the countries of the Ancient East, bronze was obtained more often from an alloy of copper with various proportions of tin. In comparison with copper, bronze alloys are characterized by low melting properties, high casting qualities, and great strength. Depending on the purpose of the casting, from 1-2% to 8-10% tin was added to the metal. The more tin was added, the more fragile the piece was.

If ore was smelted in the immediate vicinity of mining sites, copper and bronze items were cast in settlements. To obtain a bronze alloy, copper and tin or copper and arsenic, taken in certain proportions, were placed in clay crucibles, which were placed in a furnace. Molten metal from crucibles was poured into molds of sand, stone, wood. First, they used open and then closed sash forms. Weapons, tools and various tools were cast in molds. Artistic and jewelry items were cast using a wax model. The model was molded from wax, on which finely exhausted clay was applied in layers until the clay wall became strong. Special holes were left in the clay mold to melt the wax and pour the bronze alloy inside. Upon cooling, in order to remove the object, the clay was broken, and to obtain a new casting, the whole process had to be repeated anew. Wax-cast items are of artistic value.

Non-ferrous metal ores were poorly available for mining; tin deposits - the main raw material for bronze alloys - were known in antiquity on a rather limited scale. The metal had to be transported from the ore mining site over very long distances. All this prevented the widespread introduction of non-ferrous metals into production. According to F. Engels, “... bronze provided usable tools and weapons, but could not supplant stone tools; only iron could do it, and they did not know how to extract iron yet ”(K. Marx, F. Engels Soch., vol. 21, p. 161).

The special properties of the new material were quickly mastered, more productive tools and weapons were created, which could not but affect the development of agriculture and crafts.

Like gold and silver, copper is sometimes found in the earth's crust as nuggets. Perhaps the first metal tools were made from them about 10 thousand years ago. The spread of copper was promoted by such properties as its ability to be cold forged and ease of smelting from rich ores. In Cyprus, already in the 3rd millennium BC, copper mines existed and copper was smelted. From here comes the Latin name for copper - suprum. Copper mines appeared on the territory of Russia 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 khalkos, from the name of the city of Chalkis. Many terms in geochemistry and mineralogy originated from this word, for example - chalcophilic elements, chalcopyrite. The 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.

A simple substance copper is a plastic metal of golden-pink color. In the periodic table it occupies cell number 29 (symbol Cu) with an atomic mass of 63, 55 amu.

Chalcopyrite crystal 4х5х4 cm.Nikolaevsky mine, Primorsky Krai.

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

Copper ore reserves for 2016

The largest copper-producing country is Chile. On its territory there is the world's largest copper deposit, Chuquicamata, where copper ore has been mined in an 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. For 2011, the cost of copper was about $ 9000 per ton. Due to the global economic crisis, the price of most raw materials fell, and the cost of 1 ton of copper in 2016 did not exceed $ 4,700.

add to Favorites to Favorites from Favorites7

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

The design of products, which has been mastered over 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 even in this case, the original material of natural origin was in front of the master's eyes. Even in the process of mastering the production of ceramics, the natural processes of firing clay in the flame of a fire were imitated. Manufacturing of products from ore metal is a revolutionary technology, a technology that could not be "spied" in nature! This is the first completely artificial technology in the history of civilization. How did a person learn how to receive and process metals? Consider a modern version of this amazing process.

What do lobster shells and super steel have in common in the near future? Scientists have found that the chitinous base of the shell, which consists of carbon, hydrogen and nitrogen, is a honeycomb structure of polymer crystals about a nanometer in size, the free space of which is filled with protein. This allows the material to simultaneously float in water and have a strength higher than that of many special-purpose steels. It remains to study and apply natural technology in practice. So, the analysis of natural processes and structures is the key to the success of innovative technologies of the XXI century. However, man 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 the stone. The most primitive stone products were ordinary river pebbles, chipped from one edge. The oldest stone tools date back to a period of about 2.5 million years. The most important event was the development of flint tools.

In flint, the shape of such fundamental items for technical progress as an ax, sickle, knife, and hammer was first found and embodied. 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 searching, extracting stones and making from them not only tools of labor, but also jewelry for primitive people had become an everyday thing and turned into a kind of industry.

It was in the process of searching for stones suitable for the manufacture of new products that a person drew attention to the first nuggets of metals, apparently copper, which are much more common in nature than nuggets of noble 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, America. There are still copper nuggets weighing several kilograms. The largest manifestation of native copper is considered to be a solid copper vein found on the Cusinow Peninsula (Lake Superior, USA). Its mass is estimated at about 500 tons.

Not only noble metals can be present in earthly conditions in their native form. 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, and cast iron. They are found in the form of small leaves and scales embedded in rocks, most often in basalt. Native iron in the twentieth century was found, for example, on Disko Island near the coast of Greenland, in Germany (near the city of Kassel), in France (department of Auvergne), in the United States (Connecticut). It always contains a significant amount of nickel, impurities of cobalt, copper and platinum (from 0.1 to 0.5 wt% of each element) and, as a rule, is very poor in carbon. There are known finds of native cast iron, for example, on the Russkiy Islands (in the Far East) and Borneo, as well as in Avaria Bay (New Zealand), where the native alloy was represented by cogenite - iron-nickel-cobalt carbide (Fe, Ni, Co) 3C.

Observing 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 metal forming. The development of 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 typical stone chips, but changed its size and shape without violating 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 humans. In addition, forging has been observed to increase the hardness and strength of the metal.

At first, ordinary pieces of hard stone were used as a hammer. The primitive craftsman, holding the stone in his hand, struck them with blows on a piece of native, and later - smelted from ore metal. The evolution of this simplest method of forging led to the creation of the prototype of the blacksmith's hammer, equipped with a handle. However, cold forging metal processing 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.

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

When extracting 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 how to cast products, receive wire and foil, gold was first refined. In fact, all metallurgical technologies used in the era of the Ancient World for silver, copper, lead, tin were originally worked out on gold.

However, the basis of civilization up to the 3rd millennium BC. e. there remained a stone. The transition to large stone tools became a characteristic feature of the early Neolithic technique. Their appearance is associated with the development of new technological methods of stone processing - drilling, sawing, grinding. Composite ("insert") tools were invented, in which stone material was used only for the working part, and the handles were made of wood, horn or bone. The repair of tools was gradually developed - their refurbishment as the working part wears out. Mining emerged, in which fire was used to destroy rocks. An amazing technical achievement of the 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 possessed a variety of knowledge about natural substances and materials, methods of processing them.

Thermal technologies of the Neolithic

The most important distinguishing feature of a producing Neolithic economy is the creation of a food supply. When solving the problem of making utensils for storing it, ceramic products are invented and thermal technologies are gradually developing. The first items made of ceramics were baskets made of twigs, coated with clay and fired at the stake. Then, special kilns for roasting were created - forges.

Neolithic oven adapted for natural blowing

Modern reconstructions reproduce the Neolithic method of firing ceramics as follows. The horn was built on the steep bank of the river, within 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 furnace was filled with pre-dried pots, the top was covered with pot scrap and a low fire was made using raw wood. Such a fire was maintained until the separation of vapors ceased, after which the fire was intensified to a red heat. The pots were kept in this fire for at least 6 hours. Then the top of the forge 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 increased. Finally, the top of the forge was opened and the finished pots were taken out. Such ancient kilns for 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, requiring reliable high temperatures, an artificial blast furnace was needed. For the first time such kilns were created for pottery production. Thus, a person got acquainted with ore metal during the burning of clay pots. There was a process of metal recovery from substances applied to 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 the application of colored patterns on ceramics is one of the oldest forms of art.

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

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

The 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 referred 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 mine Aibunar, 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. Gold jewelry and objects decorated with complex ornaments attract particular attention, but massive copper tools, tools and weapons are of equal interest to specialists.

The gold and copper of the Balkan-Carpathian metallurgical province posed an unexpected problem for researchers of the ancient metal: what were the general efforts of this metallurgical production aimed at? Casting and forging metal tools to increase productivity, as described in most well-known textbooks, or something else? The calculations of archaeologists have shown that from the very first steps of mining and metallurgical production, the overwhelming share of its energy was directed to the creation of those products that served the symbolic spheres of public life - jewelry, attributes of power and ritual objects. A giant piece of metal served as a kind of evidence of the social significance of the dead. Thus, for several millennia, metals performed primarily a social rather than a production function.

In the 5th millennium BC. e. in most parts of Eurasia, oxidized copper ores were actively developed, the veins of which came to the surface. Mine workings were narrow slots that were formed as a result of the excavation of ore-bearing veins. If a miner stumbled upon a powerful ore lens, the gap would turn into a cavity at the mine site. The oldest copper mines are found in Mesopotamia, Spain and the Balkan Peninsula. In the era of antiquity, the island of Cyprus became one of the largest deposits of copper, from its late Latin name "cuprum" the modern name of copper as a chemical element originated. The Russian name for the metal comes from the ancient Slavic word "smida", meaning 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 \u200b\u200bthe term "smida" began to be used to denote a person working with metal, and was fixed in the form "smith" (English) or "schmidt" (German) - "blacksmith".

The development of underground ore deposits was developed in the 4th millennium BC. e. The depth of mine workings reached 30 m and more. Fire, water and wooden wedges were used to crush the rock. A fire was made near the area under development, the rock was heated up, and then quickly cooled by pouring abundant water. Wooden wedges were driven into the resulting cracks, which were also watered. Swelling, the wedges split the rock. The fragments of ore rock were again heated in a fire flame, sharply cooled and crushed with hammers and picks directly in the mines. The crushed ore was recovered from the mines in leather bags or wicker baskets. Then it was pounded in large stone mortars to the size of a pea. The ancient metallurgists used charcoal, dense wood, 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, holes were provided in the lid for the outlet of gases. In the neolithic pottery hearths described above, a temperature (up to 1100 ° C) was reached, sufficient to obtain copper containing up to 2% of the mass. natural impurities of arsenic, nickel, antimony. Subsequently, pit furnaces were installed to smelt copper. In this case, an earthen 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 melting site, 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 usually amounted to several tens of grams, so they gradually switched to the production of copper in pits directly from ore. For this, copper ore, mixed with charcoal, was placed in pits up to 30 cm deep, the bottom of which was lined with stones. Some more charcoal was poured over the layer of the charge, and tree branches and a small amount of earth were laid on top so as not to impede the flow of air into the heap. They tried to locate the melting point on the slopes of the hills in order to use the natural movement of air. This was the first "industrial" metallurgical unit.

Upon completion of the smelting, the unburned fuel was removed and the resulting metal was crushed into convenient pieces. This was done immediately after the metal had solidified, 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 cold forged. It was discovered very early on that copper is a soft and malleable metal, easily compacted and freed from coarse inclusions during the simplest machining.

With many advantages, copper, even naturally alloyed, had a very significant disadvantage: 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, during the Copper-Stone Age (4th millennium BC), the stone successfully competed with copper, which is reflected in the name of the era. The decisive step in the transition from stone to metal was taken after the invention of bronze.

As you know, stone was the main material from which primitive people made tools. No wonder the hundreds of thousands of years that elapsed between the appearance of man on earth and the emergence of the first civilizations are called the Stone Age. But in the 5-6 millennia BC. e. people have 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 work them in the same way as a stone, that is, by upholstering, grinding, squeezing out flakes, etc. But very quickly the difference between stone and copper became clear. Maybe even, initially, people decided that there would be no use from metal nuggets, especially since copper was soft enough, and the tools that were made from it quickly failed. Who invented to melt copper? Now we will never know the answer to this question. Most likely, everything happened by accident. An annoyed man 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 into a shiny puddle, and after the fire burned out, it froze. Then it only took a little thought - and the idea of \u200b\u200ba 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 characteristics even to stone. As mentioned above, copper is too soft a metal. Its main advantage was fusibility, which made it possible to make a 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 millennia should have passed. After all, technologies were created gradually, at first - by uncertain, 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 antiquity Britain was called the "Tin Islands" - many peoples equipped there trade expeditions for tin.

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

Iron has been known since the Bronze Age on Earth. However, the raw iron produced by processing at low temperatures was too soft. Meteoric iron was more popular, but it was very rare, it could only be found by chance. However, meteorite iron weapons were expensive and very prestigious to own. The Egyptians called the daggers, forged from the meteorites that fell from the sky, Heavenly.

It is generally accepted that the processing of iron was widespread among the Hittites living in the Middle East. They are about 1200 BC. e. learned to smelt real steel. For a time, the Middle Eastern powers became incredibly powerful, the Hittites challenged Rome itself, and the Philistines mentioned in the Bible owned vast territories in the modern Arabian Peninsula. But soon their technological advantage came to naught, 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 turns into steel. When the surrounding peoples learned to build such melting furnaces, steel production began literally throughout Europe. Of course, a lot depended on raw materials. After all, people have only relatively recently learned to enrich raw materials with additional substances that give new properties to steel. For example, the Romans mocked the Celts, because many Celtic tribes had such poor 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 worshiped the products of the master armourers 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 distribution of plastics, which occurred in the twentieth century, could not displace metal from most spheres of human activity.

It might be useful to read: