Lecture on the topic "man discovers the world of metal." When was metal first used? What metal did ancient people learn to smelt first?

Copper can rightfully be called the first metal of humanity, because people began to use it more than 10,000 years ago - in the Stone Age. Over the centuries, people have learned to properly handle metal, processing it in the most in various ways- using hammers, heating, casting or by alloying (mixing) with other metals such as lead, silver, zinc or tin. The discovery that copper and zinc combine well marked the beginning of an entire era called the Bronze Age.

All great cultures and peoples have worked with copper: the Colossus of Rhodes was built from copper, and the ancient Egyptians used copper to build their aqueducts. The Romans were the first to give this metal a name: They called copper “aes cyprium” (ore from Cyprus). Later it was called "cuprum" for short. From this word the names of copper were formed in many European languages (copper, Kupfer. cuivre).

In nature, copper is found as a native metal and also in minerals. This raw material is found on all continents and a decrease in its reserves is not yet expected, because copper is not consumed, but only used, which is ensured by the recycling of this metal. This saves copper in natural resources and corresponds to the ideal handling of minerals.

The most significant copper deposits today are located in Chile and the United States, where about 20 percent of the world's known reserves are concentrated. Other important production regions include Africa, Australia, China, Canada, Indonesia, South America, Russia and Poland. There are also small deposits of copper in Europe. Unfortunately, many of them have already exhausted themselves.

The earth's copper reserves will last for a very long time, because despite the annual increase in copper ore production, known deposits are not decreasing, but are even growing. The reason for this is the discovery of more and more new deposits of this metal. In addition, constantly evolving development and extraction processes and techniques are leading to an increase in usable reserves of raw materials.

Studies confirm that known world reserves increased from 90 million tons (1950) to 280 million tons (1970), and by 1998 they reached 340 million tons. Recent estimates place global copper reserves at more than 2.3 billion tons.

Copper ore is mined both open-pit and in mines. Before the actual metallurgical processing of copper ore, the “waste” accompanying rocks are separated, resulting in an ore concentrate with a copper content in the range of 20–30 percent after flotation (flotation enrichment). Copper concentrates are processed exclusively by the pyrometallurgical method, and oxide copper ores (copper ores approx. 15-20%) by the hydrometallurgical method, resulting in refining (purification), during which the remaining impurities are removed.

Today, the most preferred technology is electrolysis.

Did you know that copper, as a natural, limited in quantity and therefore valuable raw material, is not consumed, but is used in various forms and can it be reused after use?

That is why the ancient Egyptians designated copper with the so-called “ankh” symbol, meaning “eternal life” - indeed, the most appropriate name. Because this metal, since its discovery, can be used without any restrictions. Therefore, there is hardly any doubt that somewhere on Earth copper, which was once mined in Ancient Egypt, is still actively used.

The reason for this is its unproblematic meltability. This is what makes it possible to regenerate copper indefinitely.

More than 80% of the copper ever mined is currently still in circulation.

(Slide 1) A person uses various materials to meet his vital needs. The entire history of mankind is connected with the development of materials. The materials gave names to entire eras: Stone Age, Bronze Age, Iron Age.

Stone Age, the oldest period in the development of mankind. The Stone Age is divided into ancient (Paleolithic), middle (Mesolithic) and modern (Neolithic).

Paleolithic – the ancient Stone Age, the first period of the Stone Age, the time of the existence of fossil humans (paleoanthropes, etc.). The Paleolithic lasted from the emergence of man (over 2 million years ago) until approximately the 10th millennium BC.

(Slide 2) Hundreds of thousands of years ago, in the Old Stone Age (Paleolithic), people used tools made of stone. Such tools were made by splitting stones suitable shape. At first these were rough, unpolished wedges.

(Slide 3) At an early stage of its development, man also used other natural materials: wood, bone. Using beaten stone, wood, and bone tools, people hunted and gathered. About 500,000 years ago, people began to make fire using stone.

(Slide 4) Mesolithic - Middle Stone Age, transition from Paleolithic to Neolithic (X - V millennium BC). In the Mesolithic, bows and arrows, microlithic tools appeared, and the dog was domesticated. They began to use fire to burn clay to make household utensils.

(Slide 5) The first Neolithic cultures appeared around 7000 BC. e. In the Neolithic era, the new Stone Age, man learned to process stone: drilling, grinding, sawing, polishing, etc. A wide variety of stone tools appeared, the processing of wood and bone was improved, and pottery appeared.

(Slide 6) The Copper Age (Chalcolithic) is a transitional period from the Stone Age to the Bronze Age (IV–III millennium BC). Stone tools predominate, but copper ones also appear. The main occupations of the population are hoe farming, cattle breeding, and hunting.

At this stage of human development, metals began to be used, which are among the most common materials. Metals as a group of materials, known since ancient times, played a huge role in the development of the material culture of human society. With the development of human society, the use of metals also expanded. Gradually, metals became more and more important and necessary for people.

(Slide 7) Bronze Age, a historical period that replaced the Chalcolithic and is characterized by the spread of bronze metallurgy, bronze tools and weapons at the end of the 4th – beginning of the 1st millennium BC. e. In the Bronze Age, nomadic cattle breeding and irrigated agriculture, writing, and slavery appeared (the Middle East, China, South America, etc.).

(Slide 8) Iron Age, a period in the development of mankind that began with the spread of iron metallurgy and the manufacture of iron tools and weapons. Replaced by the Bronze Age at the beginning of the 1st millennium BC. e. The use of iron gave a powerful stimulus to the development of production and accelerated social development.

Modern technology cannot be imagined without metal materials.

Now it is impossible to determine exactly when people began to mine and process metals. We can only guess which metal was the first to find practical application. Obviously, the first to be used were metals that are found in nature in a pure, native form.

(Slide 9) Judging by the results of excavations and archaeological research, gold has been known to mankind since ancient times. Perhaps gold was the first metal with which man became acquainted. It has always attracted people with its brilliance. In nature, gold occurs primarily in the form of nuggets; compared to other metals, it is easily processed.

(Slide 10) Since ancient times, gold has been used to make various items. True, it was impossible to make tools or weapons from gold, but acquaintance with and handling gold brought people experience that would be useful to them in the future when processing other metals.

The Sumerians, who lived at the turn of the 3rd - 4th millennia BC. along the Tigris and Euphrates rivers, they made gold products that today remain as shiny and pure as they were in those distant times.

There is evidence of gold mining and the manufacture of products from it in Ancient Egypt (4100-3900 BC), India and Indochina (2000-1500 BC), where it was used to make money, expensive jewelry, and works of art. cult and art.

According to some data, in China already around 2250 BC. e. there was a gold coin. In Western Asia and Africa, the gold coin appeared much later. The Phoenicians, especially in later times, used gold as an instrument of exchange and were zealous in its production.

Egypt learned to process gold in the late Neolithic. In 2900 BC. the founder of the ancient Egyptian state, Menes, ordered that the unit of value expressed by a gold bar weighing 14 g be named after him. Gold came to the pharaohs from Nubia, where they owned gold mines.

(Slide 11) From archaeological excavations we know about the treasures of the tomb of Pharaoh Tutankhamun, who died young around 1350 BC. His elaborate golden sarcophagus alone weighed 110.4 kg. Even today, the art of goldsmiths who perfectly mastered metal processing techniques is admired.

(Slide 12) From the images found in the tomb of Pharaoh Mererub (VI dynasty of the Old Kingdom), one can judge the metal processing technology achieved in Egypt four thousand years ago. In the first picture, an official weighs out metal (gold) and a scribe writes down the quantity. In the second picture, six people are inflating the melting forge with pipes similar to glass blowers. Then the master pours the molten metal from the crucible into a mold standing on the ground, while an assistant holds back the slag. The ingot is beaten with stones (hammers) and brought to the finished product. At the top of the image you can see the manufactured vessels.

Excavations of ancient burial mounds in Denmark have shown that weapons and household items were made mainly of gold and only certain parts of iron. Apparently, manufacturers could dispose of copper and gold quite freely, but had to economize on iron. Observations of the natives of the American and African continents also showed that the use of gold and silver preceded the use of other useful metals. When other metals were discovered and methods of processing them were discovered, gold, due to its rarity and beauty, became a particularly valuable item of decoration and acquired the right to the name “noble metal” over all other metals. Gold retains this significance to this day.

(Slide 13) Today it is generally accepted that the Bronze Age was preceded by a period when weapons and tools were made of copper. According to some archaeological data, copper was well known to the Egyptians as early as 4000 BC. e. Mankind's acquaintance with copper dates back to an earlier era than with iron. This is explained, on the one hand, by the fact that copper occurs in nature in the form of nuggets, and on the other, by the relative ease of obtaining it from compounds. It is possible that the first small copper objects, such as arrow and spear points, were forged from found nuggets. Ancient Greece and Rome received copper from the island of Cyprus (Cyprum), hence the name Cuprum.

(Slide 14) Then people discovered that during cold forging, copper not only takes the desired shape, but also becomes harder and stronger, and if the hardened metal is heated over a fire, it will become soft again. But before people learned to melt copper and cast it into molds, a lot of time passed. Copper mining began in various areas of Ancient Egypt during the time of Pharaoh Snefru, around the middle of the 3rd millennium BC.

In addition to all its advantages, copper had a very significant drawback: copper tools and tools, such as knives, quickly became dull. Not having high strength and wear resistance, even in a cold-hardened state, copper tools and implements could not completely replace stone tools. The replacement of stone tools and tools was made possible by a copper alloy - bronze.

(Slide 15) Bronze refers to alloys of copper with tin in various proportions, as well as alloys of copper with tin and zinc and some other metals or metalloids (lead, manganese, phosphorus, silicon, etc.). Bronze has better casting properties compared to copper, has greater strength and hardness, and stronger hardening as a result of cold deformation.

Tin bronze is the oldest alloy smelted by man. The first bronze products were produced around 3000 BC. e. a smelting reducing mixture of copper and tin ores with charcoal. Much later, tin and other metals were added to copper to produce bronze. Bronze was used in ancient times for the production of weapons and tools (arrowheads, daggers, axes), jewelry, coins and mirrors.

It is possible that bronze was originally obtained by accident from ore that contained both copper and tin. Then the bronze was prepared according to a certain recipe, as evidenced by the results of analyzes of ancient bronze items.

It can be assumed that metallurgy and metalworking of the Bronze Age originated in the first large cultural centers of antiquity - in the valleys of the Tigris and Euphrates, as well as the Nile. It is believed that bronze products began to be produced in Egypt at the beginning of the 2nd millennium BC. In the Middle East, the Bronze Age began somewhat earlier.

In the tomb of a high-ranking Egyptian official of the 18th Dynasty (New Kingdom, around 1450 BC), an image of the technological process for obtaining castings in those days was found.

In Europe, the beginning of the Bronze Age falls on the 2nd millennium BC.

Many outstanding bronze items from various nations have come down to us. Weapons, tools, jewelry, dishes and other objects testify to the amazing art of ancient craftsmen, who were well aware of the specific properties of copper and its alloy - bronze.

(Slide 16) Without exaggeration, we can say that the history of artistic bronze is at the same time the history of civilization. In a crude and primitive state we find bronze in the most remote prehistoric eras of mankind. Among the Egyptians, Assyrians, Phoenicians, and Etruscans, artistic bronze achieved significant development and widespread use. In the 7th century BC. e. learned to cast statues in bronze - a discovery thanks to which we owe the existence of inimitable works of art, starting with Athena Phidias and ending with the Etruscan Orator of the Florentine Museum and Marcus Aurelius Capitoline.

(Slide 17) Artistic bronze is widely used in architecture, as the main component of a temple or palace, or simply as an external ornament. The palace described by Homer in the Odyssey was surrounded by a bronze wall. In imitation of the palaces of Assyria, decorated with bronze slabs, Agrippa ordered the Roman Pantheon to be decorated with bronze ornaments. Since ancient times, bronze has been used to decorate weapons, amulets, vases and for the manufacture of various household utensils and furniture. During the time of the pharaohs, the inhabitants of Tire and Sidon conducted an extensive trade in bronze products along the shores of the Mediterranean Sea. Thanks to excavations at Pompeii, we know that bronze products were in great use in Rome and the Roman provinces.

(Slide 18) If you believe the Greek writers, the art of casting various objects from bronze (mainly statues) first arose on the island of Samos, during the time of Cyrus or Croesus, i.e. in the 7th – 6th centuries BC. e. The Bible mentions bronze sculptures made by Hiram of Tire during the construction of the Jerusalem Temple during the reign of King Solomon.

(Slide 19) In Assyria, Palestine, ancient Persia, Egypt, India, China and Japan, bronze items are found in huge quantities and are of significant artistic interest. Bronze bracelets and earrings in the shape of cylinders, tapered at the ends, were found in the graves of Chaldea and Assyria. The Louvre houses a bronze bracelet from that era, ending with a lion's head. It is known that the Temple of Jerusalem was built by Phoenician workers and was decorated with bronze ornaments. A description of this temple and its decorations is found in the Bible.

The great demand for valuable bronze stimulated the development of other sectors of the economy. Mining improved and trade expanded. In Italy, Bronze Age mines up to 130 m deep were discovered. They still preserved mine support with wooden posts and lining.

(Slide 20) Another of the first metals mastered by man is tin. The Egyptians knew it for 3000 - 4000 BC. e. and it is spoken of in the Bible. According to Aristotle, in ancient times coins were minted from tin; During Roman rule in England, vessels were made from tin. Under Henry VIII, the price of tin was equal to the price of silver. Tinning was already mentioned by Pliny.

It is known that tin began to be mined earlier than iron. Tin mines operated in Mesopotamia (present-day Iraq) and Europe as early as 4,000 years ago.

Tin is a soft white metal that can be alloyed with copper to create bronze. Tin, necessary for smelting bronze, is not found everywhere. The Phoenicians, the best sailors and traders of antiquity, reached the southwestern part of the British Isles and found a deposit of tin ore (cassiterite) there. Phoenician merchants traded tin along the entire European coast of the Mediterranean Sea, they exchanged this metal for fabrics and precious stones.

(Slide 21) Tin is a rather rare, but very useful metal. It doesn't rust. The metal was obviously inaccessible and expensive, since tin objects are rarely found among Roman and Greek ancient products, although there is a mention of tin in the early books of the Old Testament (in the Fourth Book of Moses - Numbers).

(Slide 22) In addition to bronze, people increasingly began to use another metal, even more suitable for making tools and weapons - iron. Its history also begins in ancient times. The use of iron gave a powerful stimulus to the development of production and accelerated social development. Iron is also called the metal of the power of civilizations. The advent of the Iron Age is associated with the discovery of a method for obtaining iron from ores located in the bowels of the Earth.

It has not yet been possible to establish where and how iron was first mined in large quantities. The oldest iron item found in Egypt dates back to the 4th millennium BC, it is a necklace made of forged strips of meteorite iron.

(Slide 23) Meteoric iron is chemically pure (does not contain impurities), and therefore does not require labor-intensive technologies for their removal. Iron in ores, on the contrary, requires several stages of purification. The fact that it was “heavenly” iron that was the first to be recognized by man is evidenced by archeology, etymology, and myths widespread among some peoples about gods or demons who dropped iron objects and tools from the sky.

The first iron - a gift from the gods, pure, easy to process - was used exclusively for the manufacture of “pure” ritual objects: amulets, talismans, sacred images (beads, bracelets, rings, hearths). Iron meteorites were worshiped, religious buildings were created at the site of their fall, they were ground into powder and drunk as a cure for many ailments, and carried with them as amulets. The first meteorite iron weapons were decorated with gold and precious stones and used in burials.

In the south of Mesopotamia, where the Sumerian city-state of Ur was once located, a dagger with a gilded handle, also made from meteorite iron, was found around 3100 BC. Meteoric iron was processed in the same way as copper. During cold forging, it acquires the desired shape and at the same time becomes stronger and harder, and annealing in fire again makes the forged metal softer.

In the ancient world, iron was surrounded by an aura of mystery, apparently due to its origin. The Sumerians called it “heavenly copper.” In the Hittite cuneiform tablets, which indicate the geographical location of all then known metals, iron is said to “come from the sky.” The Egyptians always depicted iron objects as blue, the color of the sky.

(Slide 24) First in large quantities iron appeared among the Calibres, a legendary people who lived in Transcaucasia around 1500 BC. They learned to smelt it from ore containing iron. Agricola’s book “On Metals” describes the production of cryogenic iron in cheese furnaces.

(Slide 25) At first, iron was very expensive. In Babylon under King Hammurabi (1728 - 1686 BC), iron was 8 times more expensive than gold and 40 times more expensive than silver. One of the Assyrian kings, who lived three thousand years ago, was famous for his iron treasures, which were more valuable to him than gold. Achilles, the hero of ancient Greek myth, killed his opponent in order to take possession of his iron armor.

(Slide 26) Impressive masterpieces were created by the metallurgists of ancient India. In Delhi there is the famous Kutub Column, weighing 6 tons, 7.5 m high and 40 cm in diameter. It consists of individual crits welded in a forge. Even more surprising than the size of the column is the fact that so far no rust has formed on it.

(Slide 27) Ancient Indian metallurgists were also famous for their steel. Indian swords were highly valued in ancient times. During excavations of ancient burials, steel weapons made in the middle of the 1st millennium BC were found. Already at that time, Indian craftsmen mastered the art of preparing “real” Damascus steel.

(Slide 28) In China, cast iron was first smelted from ore, which was then smelted into steel, or castings were made from cast iron. Foundry technology there reached high perfection earlier than in other countries. Bronze and cast iron in Ancient China were the favorite materials for casting monumental figures. In the garden of an ancient Buddhist monastery there is a cast iron lion 6 m high.

(Slide 29) Soft and relatively easily accessible lead was used in ancient times for various purposes. Pipes were made from bent lead sheets. Coins, medals and seals were minted from lead, and sinkers for fishing equipment and anchors for ships were made. Text was engraved on thin lead plates and, by stitching them together, lead books were made.

Presumably, the first information about lead comes from India. Lead ingots in the form of bricks served as a trade item; they are also mentioned in the lists of goods that the Egyptian pharaohs received as tribute. On the islands of the Mediterranean Sea, in Italy, on the coast of Greece and in many places in Western and Central Europe, traces of ancient lead mines have been preserved.

(Slide 30) Antimony was known much less than lead - a silvery-white, highly shiny, very brittle metal. In Babylon, vessels were made from it as early as 3000 BC. However, not metallic antimony, but its compounds were used much more widely, in particular in cosmetics. Obviously, antimony also served as an alloying element in the smelting of antimony bronzes, which have excellent casting properties.

Much later, during the period of fascination with alchemy, antimony acquired special significance, primarily because in its molten form it dissolves many other metals well - “devours” them. Alchemists chose the wolf as a symbol of this metal.

Antimony looks like an ordinary metal with a traditional gray-white color with a slight bluish tint. The more impurities, the stronger the blue tint. This metal is moderately hard and very fragile: in a porcelain mortar and pestle, this metal can be easily crushed into powder.

(Slide 31) The Romans called mercury “argentum vivum” - living silver. This amazing metal is the only one that remains in a liquid state at normal temperatures. Mercury is not difficult to obtain from its natural compound with sulfur - the well-known cinnabar. The first written mention of mercury belongs to Aristotle and dates back to approximately 350 BC, but, as archaeological finds show, it was known much earlier.

(Slide 32) In ancient times, mercury was widely used for gilding. Gold easily dissolves in mercury and forms an alloy with it - gold amalgam, which is applied to the product being processed. Then it is heated, the mercury evaporates, and a layer of gold remains on the product.

(Slide 33) Silver, known to man since ancient times, is found in nature in the form of native metal . This predetermined the significant role of silver in the cultural traditions of various peoples. Various jewelry was made from silver, and it was used for minting coins. In Assyria and Babylon, silver was considered a sacred metal and was a symbol of the Moon. In the Middle Ages, silver and its compounds were very popular among alchemists. Since the middle of the 13th century, silver has become a traditional material for making tableware. Silver is still used to mint coins.

(Slide 34) In addition to bronze and steel, alloys of lead and tin and brass were known. Brass was used back in the time of Homer (8th century BC). Under Emperor Augustus (63 BC – 14 AD), brass coins were minted in Rome. Brass lends itself well to pressure processing, so parts from it are often made using the deep drawing method.

However, it was not yet known that brass contains another metal - zinc. Europe learned about zinc only in the 18th century from the Freiberg metallurgist Johann Friedrich Henckel (1675 – 1744). The Chinese knew this metal before.

(Slide 35) During the collapse of the Roman Empire, people already had solid knowledge in the field of metallurgy. They mastered the extraction and processing of many metals: gold, silver, copper, iron, tin, lead, mercury and antimony.

(Slide 36) Thank you for your attention.

List of sources used.

1. Beckert M. The world of metal./Ed. V.G. Lutzau. – M.: Mir, 1980

2. Golden Fund of Encyclopedias (electronic version):

Great Soviet Encyclopedia
Illustrated Encyclopedic Dictionary
Russian encyclopedic dictionary
Encyclopedia of Brockhaus and Efron
Great encyclopedia Cyril and Methodius.

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Metal categories

Precious or noble metals include a number of substances that have increased wear resistance and are not susceptible to corrosion and oxidation. In addition, their preciousness is determined by their rarity. There are 8 types in total and they are:

. Plastic, does not corrode, ρ (density) = 19320 kg/m3, melting temperature – 1064 Cᵒ.
. It has ductility and malleability, has high reflectivity, electrical conductivity, ρ = 10500 kg/m3, melting point – 961.9 Cᵒ.
. Viscous, refractory, malleable element, ρ = 21450 kg/m3, melting temperature – 1772 Cᵒ.
. It is soft and malleable, has a silver-white color, the lightest, fusible, plastic element, does not corrode, ρ = 12020 kg/m3, melting t – 1552 Cᵒ
. Hardness and refractoriness are above average, distinguished by its fragility, unaffected by alkalis, acids and their mixtures, ρ = 22420 kg/m3, melting temperature – 2450 Cᵒ
. Externally similar to platinum, however, it has greater hardness, brittleness and refractoriness, ρ = 12370 kg/m3, melting point – 2950 Cᵒ.
Rhodium. Hardness above average, refractory, brittle, has high reflectivity, not exposed to acids, ρ = 12420 kg/cm3, melting temperature – 1960 Сᵒ
Osmium. Heavy, has increased refractoriness, above average hardness, brittle, not susceptible to acids, ρ = 22480 kg/m3, melting point – 3047 Cᵒ.

Elements similar in their chemical structure and color (silver-white). There are 17 types of these metals. They were discovered in 1794 in Finland by chemist Johan Gadolin. By 1907, there were already 14 of these elements. The modern name “rare earth” was assigned to this group by the end of the 18th century. For a long time, scientists assumed that elements belonging to this group were rare. The following rare earth metals are known:

Thulium;

Regarding chemical properties, then metals form refractory and water-insoluble oxides.

First exploration of metals

The 4th millennium BC brought fateful changes to humanity. Most important process began the development of metals. At this time, a person discovers metals such as copper, gold, silver, lead and tin. Copper was mastered most quickly.

Initially, the metal was extracted from ore by roasting over an open fire. This technique was mastered around the 6th-5th millennium BC in India, Egypt and Western Asia. Copper was most widely used for the manufacture of tools and weapons. Having replaced stone tools, copper greatly facilitated human labor. They made objects of labor using clay molds and molten copper, poured it into the molds and waited until it cooled.

In addition, the development of copper gave a new round in the development of the social system. This marked the beginning of the stratification of society by wealth. Copper became a sign of wealth and prosperity.

By the 5th millennium, people became acquainted with precious metals, namely silver and gold. Scientists suggest that the first was a copper-silver alloy, it was called billon.

Products made from these metals are finds from ancient burials. In ancient times, these elements were mined in Egypt, Spain, Nubia, and the Caucasus. Mining also took place in Russia in the 2nd-3rd millennium BC. If metals were mined from placers, they were washed with sand on trimmed animal skins. To extract metal from ore, it was heated, it cracked, then it was crushed, ground and washed.

In the Middle Ages, most of the mining was silver. Most of the production took place in South America (Peru, Chile, New Granada), Bolivia, and Brazil.
At the beginning of the 16th century, the inhabitants of Spain discovered platinum, which was very reminiscent of silver and therefore its diminutive version of the Spanish word “plata” - “platina”, which means small silver or silver. From a scientific point of view, platinum was considered in 1741 by William Watson.

1803 - discovery of palladium and rhodium. In 1804 - iridium and osmium. Four years later, Vestium was discovered, later renamed ruthenium.

As for rare earth metals, until the 60s of the twentieth century they were not of interest in the scientific community. However, it was at this time that the technology for isolating pure metals emerged. At the same time, the powerful magnetic properties of these metals were discovered. Over time, it became possible to grow single crystals of these metals. Today, rare earth metals make it possible to produce many household items without which people cannot imagine their existence, for example, energy-saving lamps. As well as military and automotive equipment.

Modern mining of precious metals

IN modern times Gold is considered the most valuable metal. The largest amount of resources is devoted to its production. The first “gold mines” were developed in Africa, Asia and America.

Today gold is mined in South America, Australia and China. Russia is one of the largest gold-mining countries and ranks fourth in the world. Mining is carried out by 16 companies in Magadan, the Amur Region, the Khabarovsk Region, the Krasnoyarsk Territory, the Irkutsk Region and Chukotka.

Extraction methods

Until modern mining technology was invented precious metals, they were mined by hand. And to say that this is an extremely labor-intensive process means to say nothing.

So, modern gold mining processes:

Screening. This type of gold mining was popular during the Gold Rush in America. This method required a lot of effort, patience and skill. The main tools were sieves, buckets with grates at the bottom, or bags. In order to find even a drop of gold, a person went into the river up to his waist, scooped up water and poured it onto a sieve and into a bucket with a lattice bottom. Thus, large stones and gold particles remained on its surface. In this case, a sieve or lattice bottom had to be constantly held on the surface in order to wash out unnecessary stones, sand and water and leave only particles of precious metal. Today this method is rarely used.
Extraction from gold ore. This is also a manual method of extraction. Here the tools were a shovel, a hammer for crushing ore and a pick. This method involves climbing mountains, digging soil, trenches and mines. Such mining was carried out mainly in Russia.
Industrial method. Thanks to the development of science and the discovery of certain chemical compounds, the rate of extraction has increased significantly, and the use of small and large equipment has also begun. This process is automatic and requires virtually no human intervention.

Industrial production, in turn, is divided into:

Almagalmirovaniye. The meaning of this method lies in the interaction of mercury and gold. Mercury has the property of attracting and enveloping the precious metal. To detect metal, ore is poured into barrels with mercury at the bottom. The gold was attracted to the mercury, and the rest, the devastated ore, was discarded. This method was in demand and effective in the mid-20th century. It was considered quite cheap and simple. However, mercury is still a toxic element and therefore the method was abandoned. Adhered particles of precious metal could not always be completely separated from the mercury, which is not practical and leads to the loss of part of the mined metal.
Leaching. This method is produced using sodium cyanide. With the help of this element, precious metal particles transform into a state of water-soluble cyanide compounds. After this, they are returned to a solid state using chemical reagents.
Flotation. There are varieties of gold-bearing particles that are resistant to water and do not get wet. They float on the surface like air bubbles. This type of rock is crushed, then poured with liquid or pine oil and mixed. The required gold particles float up like air bubbles, they are purified and the final result is obtained. If we are talking about an industrial scale, then pine oil is replaced with air.

Modern processing technologies

There are two ways to process precious metals.

Casting

This method is relatively simple. Indeed, all that is required is to pour the molten metal into a pre-prepared mold made of copper, lead, wood or wax. After complete cooling, the product is removed from the mold and polished.

Special melting furnaces are used to soften the metal. They are induction and muffle.

The induction furnace is considered the most popular and functional type of melting. In it, heating occurs due to the influence of eddy currents.
A muffle furnace allows you to heat certain materials to a specified temperature.

Muffle furnaces are divided into various types depending on the type of heating element (electric, gas), on the protective treatment mode (air, with a gas atmosphere, vacuum), on the type of design (vertical loading, bell-type, horizontal loading, tubular).

Coinage

This method is considered more complex. Here the metal is not melted, but heated to the state necessary for further work. Next, using hammers, the softened raw material is turned into a thin layer on a lead substrate. Next, the future product is given the required shape.

Applications and types of products

The first thing that comes to mind when it comes to the use of precious metals is the jewelry industry. Today we see an abundance of different jewelry and products for every taste. These include both decorations and household items, for example, tableware and dishes. Each jewel has a mark that corresponds to authenticity and a certain sample. However, this is only a small part of the scope of use of precious metals.

Their use is in demand in the automotive industry.

Platinum, iridium, palladium, and gold are indispensable in the medical field. Medical needles are a prime example of this. Also, prosthetics, various instruments, parts, and preparations are made on the basis of white metal.

In addition, high-strength and stable devices in the electrical field are manufactured using valuable metals. For example, anti-corrosion devices and devices that resist the formation of an electric arc. The catalytic properties of platinum are used in the production of sulfuric and nitric acid. Formalin is made using the chemical properties of argentum. It is difficult to imagine the oil refining industry without gold.

Stronger metals are used to melt parts used in more aggressive conditions. For example, when it comes to working with high temperatures, aggressive chemical reactions, electricity and more.

Sputtering of these metals is also used to coat others. This helps get rid of corrosion, gives protective properties inherent in precious metals.

Pricing

The price of precious metals is determined by many processes, including technical, fundamental and speculative. However, the most important factor is supply and demand. It is this factor that is taken into account when setting prices for jewelry. Demand is generated by buyers. They use metals in various industries - medical, engineering, radio engineering, jewelry. Also, the presence of products made of precious metals often determines a person’s belonging to a certain status. The most popular among others is gold. This is also due to the fact that each state has its own gold reserve, and its scale partially determines the weight of the state on the world stage.

According to the Central Bank Russian Federation the cost of one gram of gold is 2686.17 rubles, silver – 31.78 rubles/gram, platinum – 1775.04 rubles/gram, palladium – 2179.99 rubles/gram.

The birth of metallurgy. The development and spread of metallurgy was of great importance for the development of the productive forces of the material culture of mankind. Judging by archaeological finds, people were familiar with native metal (copper, gold, meteorite iron, lead) in the Stone Age. Nuggets were used as decorations, amulets, etc. In ancient times, methods of cold forging of metals were discovered, but nuggets were rare, and this could not have economic significance. The art of metal smelting was discovered, most likely, by accident. Pieces of ore caught in a fire or kiln during ceramic production could give rise to the idea of metallurgy.

The beginning of metal processing originated in areas where there were outcrops of ore rocks on the surface. But where and when this happened is not known. There is an assumption that the birthplace of metallurgy was the region from Transcaucasia to Asia Minor, although there are copper deposits in the Carpathians, the Balkans, the Caucasus, Altai and Tien Shan and the Urals. As for the time of the emergence of metallurgical production, with each new archaeological find it has to be made more ancient. By the 8th millennium BC. e. (that is, when Mesolithic cultures still existed in most of the inhabited lands) include layers of the Chayenu-Tepezi monument in Anatolia (Turkey), where copper and bronze beads, a tetrahedral awl and wire pins were found. In the 7th millennium BC. e. the metal was mined and processed by the inhabitants of the settlements of Catal Huyuk (Türkiye). In the layers of the settlement of Yarym-Tepe I in the Sinjar Valley (Iraq), dating back to the 6th millennium BC. e., copper jewelry and slag from metal smelting were found.

Native copper is very rare and therefore, when it became scarce, people began to mine it using fire. The area where the ore was located was heated by fires and then watered; the ore was cracked and then mined using bone diggers, and large pieces were broken off with stone axes. Impacts separated the ore from the surrounding waste rock. Raw materials were transported to copper smelting centers. Here metal was smelted in the most primitive ways: the ore was piled up, covered with firewood and set on fire. Thus, the chemical composition and properties of the finished metal depended on the composition of the ore, impurities and their quantity, as well as on the smelting temperature.

It should be noted that the ore could have various impurities, as a result of which not pure copper, but some types of bronze were smelted. It is traditionally believed that man learned to make alloys of copper with impurities (ligature), most often arsenic, antimony and lead. Later (around the 3rd millennium BC) man created “classical” bronze - with the addition of tin. Four main stages in the development of copper metallurgy can be distinguished: cold (and then hot) forging, casting of native copper, smelting of copper from ore (this is the beginning of metallurgy proper), copper-based bronze alloys.

Despite the advantages of copper and especially bronze, metal not only did not replace stone, bone and wood in the production of tools, but remained a rather rare and expensive material until the Bronze Age. It can be added that for a long time copper products were mostly small - needles, awls, jewelry, knives, and copper tools repeated the shape of stone ones. Towards the end of the Chalcolithic, massive copper products began to be produced, first by forging, and later by casting. The next period is called the Bronze Age and its chronological framework for each territory is determined separately.

When casting, less metal is spent on the product, and the shapes of the tools become more elegant. Axes, hammers, needles, awls, chisels, punches, and jewelry are cast. Casting requires temperatures of over 1000 degrees. By the 3rd–2nd millennium BC. e. metallurgical production has improved somewhat. Bronze smelting began to be carried out in furnaces using coal, which improved the recovery process. Casting was improved, including using a wax model, and the techniques of forging, chasing and hardening bronze were improved.

But the transition to tin-based “classical” bronze caused certain difficulties associated with the extraction of tin, which is quite rare. Its deposits are located far from ancient metallurgical centers. To overcome these difficulties, it was necessary to expand trade relations, means of transport, etc., which, in turn, led to the further development of productive forces.

Along with copper and bronze, people knew and used other metals: lead, gold, silver. But the scope of lead at that time was limited. Precious metals, due to their high cost, were used only for decoration; ancient craftsmen achieved high perfection in their processing. They knew how to make cast objects, decorate them with embossing, and cover the surfaces of products made from cheaper materials with the thinnest gold leaves. They also knew an alloy of gold and silver - electr, which was quite widespread (such an alloy is also found in nature).

Bronze brought a new way of life. New tools and weapons, the development of new previously unsuitable lands, increased mobility of the population, the expansion of exchange, especially metal, was accompanied by a complication of the social structure of society, expanding inequality, an increase in the number of military conflicts, and the emergence of slavery. The territories located near copper deposits were ahead of other areas in their development. And only the appearance of iron accelerated progress, and a new metal became from the 1st millennium BC. e. the main material for the manufacture of tools and weapons, finally displacing stone, bone, copper and bronze.

Man's acquaintance with iron occurred long before this. Not to mention meteorite iron (possibly native iron), which they knew how to smelt in the 3rd and perhaps 4th millennium BC. e. But it is even rarer than copper, and the first iron things were rare and expensive, used for decoration along with precious metals. There are known cases of iron inlay into gold jewelry and ceremonial dishes. The widespread use of iron as a cheap mass material occurred at the turn of the 2nd and 1st millennia BC. e.

The most ancient finds of iron production were recorded on the territory of Iranian Azerbaijan; they date back to about 2800. BC e. The experience of smelting copper allowed man to master the smelting of iron, although this requires a higher temperature. To extract iron from ore, ancient metallurgists found a way out - reducing the metal by injecting oxygen into the furnace during iron cooking (the "cheese ore method"). To do this, they used small furnaces in which the metal, one might say, was boiled rather than melted. During the smelting process, all foreign impurities and waste rock float up (this is slag), and the metal accumulates at the bottom of the furnace in the form of a spongy mass saturated with liquid slag (kritsa). This metal was soft, so it was forged repeatedly. But still, iron remained softer than bronze. Only the development of such technological processes as carburization (cementation), hardening and tempering allowed iron to take precedence over bronze.

In addition to hardness, iron had another very important advantage: iron ore is found almost everywhere, including in swamps, forest zones, mountainous areas, etc. Copper-poor countries quickly caught up with other territories in their development. The Bronze Age is replaced by the Iron Age.

Total:

The development of metal smelting became the largest technical achievement of man in the Eneolithic and Bronze Ages, but real technical revolution occurred only with the development of iron metallurgy at the end of the 2nd millennium BC. Iron ore is more common than copper ore, making iron a common metal. Metallurgy accelerated the progress of society, improved land cultivation, the development of crafts into independent production, the development of trade and the use of metals in military affairs, stimulated the formation of a class society and the emergence of a state.

“Seven metals were created by light according to the number of seven planets” - these simple verses contained one of the most important postulates of medieval alchemy. In ancient times and in the Middle Ages, only seven metals and the same number of celestial bodies were known (the Sun, the Moon and five planets, not counting the Earth). According to the luminaries of science of that time, only fools and ignoramuses could fail to see the deepest philosophical pattern in this. The harmonious alchemical theory stated that gold is represented in the heavens by the Sun, silver is the typical Moon, copper is undoubtedly related to 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 corresponding symbols.

Figure 1 - Alchemical signs of metals and planets

Currently, more than 80 metals are known, most of which are used in technology.

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

The first metal that man learned to process was gold. The most ancient things made of this metal were made in Egypt approximately 8 thousand years ago. In Europe, 6 thousand years ago, they were the first to start making gold and bronze jewelry and weapons of the Thracians, who lived in the territory from the Danube to the Dnieper.

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

In 3 thousand BC. people began to widely use metals in their economic activities. The transition from stone tools to metal ones was of enormous 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 - Schematic map of the territorial and 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. (i.e., before the Uruk-type culture spread widely in Mesopotamia), come from only three dozen monuments scattered over a vast territory of 1 million km 2. About 230 small samples were recovered from here, 2/3 of them belong to two pre-ceramic Neolithic settlements - Chayonu and Ashikli.

Constantly looking for the stones they needed, our ancestors, presumably, already in ancient times paid attention to reddish-green or greenish-gray pieces of native copper. In the cliffs of the banks and rocks they came across copper pyrites, copper shine and red copper ore (cuprite). At first, people used them as ordinary stones and processed them accordingly. They soon discovered that when copper was treated with blows from a stone hammer, its hardness increased significantly, and it became suitable for making tools. Thus, the techniques 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, revealed new features not characteristic of stone: from strong heating the metal melted and, cooling, acquired a new shape. If the shape was made artificially, it would work necessary for a person product. 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. Melting began to be carried out in special high-temperature furnaces, which were a slightly modified design well known to people pottery kilns (Figure 3).

Figure 3 - Metal smelting in Ancient Egypt (the blast is supplied by furs made from animal skins)

In southeastern Anatolia, archaeologists discovered a very ancient Pre-Pottery Neolithic settlement, Çayonü Tepesi (Figure 4), which amazed with the unexpected complexity of its stone architecture. Among the ruins, scientists discovered about a hundred small pieces of copper, as well as many fragments of the copper mineral malachite, some of which were processed into beads.

Figure 4 - Çayonü Tepesi settlement in Eastern Anatolia: IX-VIII millennium BC. The oldest metal on the planet was discovered here

Generally speaking, copper is a soft metal, much less hard than stone. But copper tools could be sharpened quickly and easily. (According to the observations of S.A. Semenov, when replacing a stone ax with a copper one, the cutting speed increased approximately three times.) 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 deposits of copper were discovered, their intensive development arose, ore and mining appeared. As the discoveries of archaeologists show, already in ancient times the process of ore mining was carried out 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 the drifts extending from each mine was several kilometers.

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

Figure 5 - Ancient mines

Figure 6 - Tools of ancient miners

At the end of 3 thousand BC. ancient masters began to use the properties of alloys, the first of which was bronze. The discovery of bronze must have been prompted by an accident inevitable during the mass production of copper. Some varieties of copper ores contain an insignificant (up to 2%) admixture of tin. While smelting such ore, the craftsmen noticed that the copper obtained from it was 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 began to be added 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 instruments were harder than copper ones and sharpened well and easily. Bronze metallurgy has made it possible to increase labor productivity several times in all sectors of human activity (Figure 7).

The production of tools itself became much simpler: instead of long and hard work beating and polishing stone, people filled ready-made forms with liquid metal and obtained results that their predecessors had never dreamed of. Casting techniques were gradually improved. At first, casting was done in open clay or sand molds, which were simply a depression. They were replaced by open forms carved from stone that could be used repeatedly. However, the big disadvantage of open molds was that they only produced flat products. For casting products complex shape they were no good. A solution was found when closed split molds were invented. Before casting, the two halves of the mold were firmly connected to each other. Molten bronze was then poured through the hole. When the metal cooled and hardened, the mold was disassembled and the 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 figure casting. But this difficulty was overcome when the closed form was invented. With this method of casting, an exact model of the future product was first molded from wax. Then it was coated with clay and fired in a kiln.

The wax melted and evaporated, and the clay took an exact 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 technical techniques for working with metals were discovered, such as drawing, riveting, soldering and welding, complementing the already known forging and casting (Figure 8).

Figure 8 - Golden hat of a Celtic priest

Perhaps the largest metal casting ever made to Japanese masters. This was 1200 years ago. It weighs 437 tons and represents 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. Let us add that the famous ancient Greek statue - the Colossus of Rhodes - 36 m high, weighed 12 tons. It was cast in the 3rd century. BC e.

With the development of metallurgy, bronze products began to replace stone ones everywhere. But don't think that this happened very quickly. Non-ferrous metal ores were not available everywhere. Moreover, tin was much less common 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 iron could do this.

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

The oldest items made of lead are considered to be the beads and pendants found in Asia Minor during excavations at Çatalhöyük and the seals and figurines discovered in Yarym Tepe (Northern Mesopotamia). These finds date back to the 6th millennium BC. The first iron rarities date back to the same time, representing small krits found in Çatalhöyük. The oldest silver items were discovered in Iran and Anatolia. In Iran, they were found in the town of Tepe-Sialk: these are buttons dating back to the beginning of the 5th millennium BC. In Anatolia, in Beyjesultan, a silver ring dating from the end of the same millennium was found.

In prehistoric times, gold was obtained from placers by panning. It came out in the form of sand and nuggets. Then they began to use gold refining (removing impurities, separating silver), in the second half of the 2nd millennium BC. In the 13th and 14th 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 ancient times, 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 (around the 3rd millennium BC in Asia Minor), and this became widespread another 1500-2000 years later.

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

Once upon a time, tin was smelted in simple shaft furnaces, after which it was purified using special oxidative processes. Now in metallurgy, tin is obtained by processing ores according to complex integrated schemes.

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

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

The use of iron began much earlier than its production. Sometimes pieces of greyish-black metal were found which, when forged into a dagger or spearhead, produced a weapon stronger and more ductile than bronze and held a sharp edge longer. The difficulty was that this metal was found only by accident. Now we can say that it was meteorite 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 ended up not on the battlefield, but in the treasury of the next ruler.

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

The peoples of Anatolia were the first to learn how to process iron. The ancient Greek tradition considered the Khalib people to be the discoverer of iron, for whom the stable expression “father of iron” was used in 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 8th century BC. e wrought iron quickly began to spread in Europe in the 3rd century BC. e. replaced bronze in Gaul, appeared in Germany in the 2nd century AD, and in the 6th century AD it was already widely used in Scandinavia and among tribes living in the territory of future Rus'. In Japan, the Iron Age did not begin until the 8th century AD.

At first, only small quantities of iron were obtained, and for several centuries it sometimes cost forty times more than silver. The iron trade restored Assyria's prosperity. The way was opened for new conquests (Figure 9).

Figure 9 - Furnace for smelting iron among the ancient Persians

Metallurgists were able to see liquid iron 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 producing elastic steel without melting iron. This steel was called damask steel, but due to the complexity of manufacturing and the lack necessary materials In most of the world, this steel remained an Indian secret for a long time.

A more technologically advanced way to produce elastic steel, which did not require particularly pure ore, graphite, or special furnaces, was found in China in the 2nd century AD. The steel was forged many times, with each forging the workpiece was folded in half, resulting in an excellent weapon material called Damascus, from which, in particular, the famous Japanese katanas were made.