METALLURGY: THE SCIENCE OF THE UNIVERSE AND MATTER
Metallurgy is one of the key branches in the Russian industry. Despite a period of economic instability, the steel industry accounts for about 10 billion dollars of exports to the EU countries and the USA. And the share of the metallurgical industry in the Russian export portfolio amounts to about 15 % of the total revenue. In addition to the great importance for the Russian economy, metallurgy is also a science of how metals emerge and how their chemical composition, structure and properties change under the influence of different processes.
Art of Metallurgy
In fact, the scientific significance of the metallurgical industry was formed much earlier than the economic one. Metallurgy was originally called the art of extracting metals from ores, and it was only nowadays that metallurgy has become an independent industry and a sector of the national economy.
Metallurgy is a science of commercial metal production. In the 16th century, the scientist and doctor Georg Agricola (his real name is Georg Bauer) laid the foundations of the modern science by writing "12 Books on Metals". In particular, it is written in these books that the main task of metallurgy is the melting of mined ore "with benefit for the cause." This means that through different processes it is necessary to separate slugs from ore and to obtain pure metals from it.
An extract from Agricola’s works says: «By subjecting ore to heating, kilning and furnacing, a part of substances mixed with metal is removed. A lot of impurities are taken away when ore is crushed in mortars, and even more when washing, screening and sorting. We cannot separate everything that hides metal from the eye by such a method. Smelting is necessary because only through it rock and hardened juices are separated from metals that acquire its color, purified and become useful in many ways to mankind».
Indeed, smelting (this physicochemical process is now called pyrometallurgical and is still part of metallurgy these days) is not the only method and not the only possible technology to mine metals. Obtaining the largest (in terms of their production) metallurgical products such as cast iron and steel and a number of other valuable metals and alloys, is based on pyrometallurgical processes. However, at the end of the 19th century, there was another widespread technology called hydrometallurgy.
In general, hydrometallurgical processes are considered necessary for the production of rare, scattered, particularly valuable metals, but this principle is not always applicable. For example, even copper is quite often mined with the help of the hydrometallurgy industry.
The pyrometallurgical processes are based on еру chemical reactions of kilning. In such a case kilning can be oxidizing (steel), regenerative, sulfatizing (copper, lead, zinc) and so forth. The hydrometallurgy processes include leaching and precipitation of metals from solutions, extraction, sorption of metals. Copper, zinc, uranium are produced with the help of sulfuric acid; molybdenum, tungsten - with the help of soda.
Despite the fact that hydrometallurgy is a more recent technology, pyrometallurgical and hydrometallurgical processes should not be opposed. They often accompany or precede each other (the hydrometallurgical processes precede the pyrometallurgical ones). Once metals have been obtained in one way or another, they undergo clean-up (refining) and thermal treatment stages to improve their physical-chemical properties, most often durability.
Electrometallurgy, powder metallurgy and metallothermy are also some special types of metallurgical processes. For example, powder metallurgy is based on the use of metal powders. These particles are very small, ranging from 0.1 μm to 0.5 mm; first, it is compressed, and then sintered. Many countries also study and implement various advanced metallurgical technologies, such as bioleaching, biooxidation, biosorption, biodeposition and solution cleaning.
History of Metallurgy
Development traces of the metallurgical industry are found in different cultures and civilizations in different times, up to the 7th and 6th millenniums BC.
The first evidence that man mined metals was discovered by archaeologists in the territories of Serbia, Bulgaria, Spain and Great Britain. Scientists found there, in particular, copper axes. Later, people learned to extract not only copper, but also tin from rock, in the 3500s BC came the so-called Bronze Age. After copper, people began to use iron. It is believed that the mining technology of this metal was invented by the people of Hittite (Indo-European people of small Asia) around 1200 B.C., and this was the beginning of the Iron Age.
Since then new and new technologies appeared: they made various tools for war and agriculture from iron and other metals and impurities, metals were also used in urban construction. As a result, the metallurgical industry developed everywhere: from the eastern nomads who knew the art of craft of the blacksmith and the inhabitants of China who learned to receive liquid cast iron, to India, where columns were made of metals, which still have no touch of rust, and Ancient Romans, engaged in mining and forging. It is believed that the founders of the metallurgical industry are Chinese because many of the methods, devices and technologies of this science were invented in ancient China, and then Europeans mastered the craft, inventing domain furnaces, cast iron, steel and so forth.
The current history of metallurgy in Russia begins with the construction of the first metallurgical factories at the Urals in the early 18th century and the creation of factory districts, which comprise not only factories, but also mines, products, forests, quarrying and ancillary production.
Industry of Metallurgy
Today the metallurgical industry includes:
- metal production;
- alloys production;
- metal processing;
- coating of metals;
- materials sciences, study of the physicochemical characteristics of metals and alloys.
Related industries are the development, production and operation of machinery, machines and equipment used in metallurgy. The production of fire-resistant materials, recycling and others is also closely associated with metallurgy.
Metallurgy is divided into ferrous and non-ferrous. This is due to the fact that metals are divided into blacks (iron and alloys) and all others. It is not difficult to guess that the ferrous metallurgy includes the mining of ferrous ores, the production of iron, steel, ferroalloys, the rolling of ferrous metals, steel, iron and other products. Non-ferrous metallurgy is the production of heavy non-ferrous (copper, lead, zinc, tin, nickel) and light non-ferrous (aluminum, titanium, magnesium) metals.
Education of Metallurgists
Enterprises use different methods and technologies for the production of different types of metals, and they constantly evolve and improve, as in other industries. Most processes are automated; IT modeling and analysis are used. Of course, it has its impact on the training of experts of the metallurgical industry, not only in specialized universities, but also directly at production sites. Often large metallurgical enterprises develop and implement such educational programs.