AI 2023. Meet ChatGPT. - page 214
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A bit of statistics:
There is both a lot and a little data on mining on the Internet - it is probably there, but it is hard to say where. Perhaps there are resources where these data are organised and presented clearly and holistically, but this is enough for general understanding. Let's move on to metallurgy.
The point of this presentation is to see:
1. The real world.
2. Real production.
3. Real technology.
4. Real economics.
5. Real development potential.
Let's continue to familiarise ourselves with the industries. Six more to go. Today we'll look at metallurgy.
Let me remind you what the point is: to finally rid your mind of Hollywood phantasmagorias and delusions about technology.
To wake up.
Metallurgy(Wikipedia)
(text edited by me for readability)
(from Greek μεταλλουργέω - extracting ore, processing metals) is a field of science and technology covering the processes of obtaining metals from ores or other raw materials, as well as the processes associated with changing the chemical composition, structure and properties of metal alloys and the production of a variety of metal products from them. In the original, narrow meaning - the art of extracting metals from ores. Currently, metallurgy is also a branch of industry.
The structural properties of metallic materials depending on their composition and processing methods are studied within the framework of metallurgy.
Metallurgy includes:
Metallurgy is adjoined to the development, production and operation of machines, apparatuses, units used in the metallurgical industry. On the conditional boundary between metallurgy and mining are the processes of pelletising (preparation of enriched raw materials for further pyrometallurgical processing). From the point of view of academic science they are referred to metallurgical disciplines. Closely related to metallurgy are coking, refractory materials, and chemistry (when it comes to rare earth metals metallurgy, for example).
Varieties of metallurgy
In the world practice, historically, metals are divided into ferrous metals (iron, manganese, chromium and alloys based on them) and all other metals- nonferrous metals or non-ferrous metals. Accordingly, metallurgy is often divided into ferrous and non-ferrous.
Ferrous metallurgy includes extraction and concentration of ferrous ores, production of pig iron, steel and ferroalloys. Ferrous metallurgy also includes the production of rolled ferrous metals, steel, cast iron and other ferrous metal products.
Non-ferrous metallurgy includes extraction and concentration of non-ferrous metal ores, production of non-ferrous metals and their alloys. By physical properties and purpose non-ferrous metals are conditionally divided into heavy (copper, lead, zinc, tin, nickel) and light(aluminium, titanium, magnesium).
Metallurgy is divided into pyrometallurgy and hydrometallurgy.
Pyrometallurgy (from Greek πῦρ "fire") - metallurgical processes occurring at high temperatures (roasting, smelting, etc.). A variation of pyrometallurgy is plasma metallurgy.
Hydrometallurgy (from Greek ὕδωρ "water") is a process of extraction of metals from ores, concentrates and wastes of various industries with the help of water and various aqueous solutions of chemical reagents (leaching) with subsequent separation of metals from solutions (e.g. cementation, electrolysis).
In many countries of the world there is an intensive scientific search for application of various microorganisms in metallurgy, i.e. application of biotechnology (bioleaching, biooxidation, biosorption, bio-deposition and solution purification). To date, the greatest application of biotechnical processes has been found for the extraction of non-ferrous metals such as copper, gold, zinc, uranium, nickel from sulphide raw materials. Of particular importance is the real possibility of using biotechnology methods for deep treatment of metallurgical waste water[6].
Production and consumption of metals
Distribution and spheres of application
Of the most valuable and important metals for modern technology, only a few are found in the Earth's crust in large quantities: aluminium (8.9 %), iron (4.65 %), magnesium (2.1 %), titanium (0.63 %). Natural resources of some very important metals are measured in hundredths and even thousandths of per cent. Nature is particularly poor in noble and rare metals.
Production and consumption of metals in the world is constantly growing. From the mid-1980s to the mid-2000s, the annual world consumption of metals and the world metal stock have doubled and amount to about 800 million tonnes and about 8 billion tonnes, respectively. The share of products manufactured using ferrous and non-ferrous metals now accounts for 72-74 % of the gross national product of states. Metals in the XXI century remain the main structural materials, as by their properties, economical production and consumption are unrivalled in most areas of application[6].
Of the 800 million tonnes of metals consumed annually, more than 90% (750 million tonnes) is steel, about 3% (20-22 million tonnes) is aluminium, 1.5% (8-10 million tonnes) is copper, 5-6 million tonnes is zinc, 4-5 million tonnes is lead (the rest is less than 1 million tonnes).
The scale of production of non-ferrous metals such as aluminium, copper, zinc, lead is measured in million tonnes/year; such as magnesium, titanium, nickel, cobalt, molybdenum, tungsten - in thousand tonnes, such as selenium, tellurium, gold, platinum - in tonnes, such as iridium, osmium, etc. - in kilograms[6].
Currently, the bulk of metals are produced and consumed in countries such as USA, Japan, China, Russia, Germany, Ukraine, France, Italy, UK and others.
Due to their physical properties (hardness, high density, melting point, thermal conductivity, electrical conductivity, acoustic conductivity, appearance and others) they find application in various fields.
The applications of metals depend on their individual properties:
Iron and steel have hardness and strength. These properties make them widely used in construction;
aluminium is forged, conducts heat well, and has high strength at ultra-low temperatures. It is used for making pots and foil, in cryogenic technology. Due to its low density - in the manufacture of aircraft parts;
copper has ductility and high thermal and electrical conductivity. This is why it is widely used in the manufacture of electrical cables and in power engineering;
gold and silver are very ductile, viscous and chemically inert, have a high value and are used in jewellery. Gold is also used to make non-oxidisable electrical connections.
Alloys and their uses
In pure form, metals are used only marginally. Much greater use is made of metal alloys, as they have special individual properties. The most commonly used alloys are aluminium, chromium, copper, iron, magnesium, nickel, titanium and zinc. Much effort has been devoted to the study of iron and carbon alloys. Ordinary carbon steel is used to create cheap, high-strength products when weight and corrosion are not critical.
Stainless or galvanised steel is used when corrosion resistance is important. Aluminium and magnesium alloys are used when strength and lightness are required.
Copper-nickel alloys (such as monel metal) are used in corrosive environments and for non-magnetic products.
Nickel-based superalloys (such as Inconel) are used at high temperatures (turbochargers, heat exchangers, etc.).
At very high temperatures, monocrystalline alloys are used.
Extractive metallurgy
Extractive metallurgy consists of extracting valuable metals from ore and preparing the extracted raw materials for further processing.
In order toconvert a metal oxide or sulphide into pure metal, the ore must be beneficiated physically, chemically, optically or electrolytically.
Thescale of ore processing in the world is enormous. In the late 1980s and early 1990s, more than 1 billion tonnes of ore were mined and beneficiated annually in the USSR alone.
Metallurgists work with two main components:
Mining is not necessary if the ore and the environment allow leaching. This can dissolve the mineral and produce a mineral-rich solution. Often the ore contains several valuable metals. In this case, the waste from one process can be used as a raw material for another process.
Iron metallurgy
Iron is naturally found in ore in the form of Fe3O4, Fe2O3 oxides, Fe2O3×H2O hydroxide, FeCO3 carbonates and others. Therefore, for the reduction of iron and obtaining alloys based on it, there are several stages, including:
Blast furnace iron production
The first stage of iron alloy production involves the release of iron from ore or pelletised raw materials in the blast furnace at temperatures above 1000 °C and the smelting of pig iron. The properties of the resulting pig iron depend on the process in the blast furnace. Therefore, by setting the process of iron reduction in the blast furnace, two types of pig iron can be obtained:
Steel production
The pig iron is used to produce steel. Steel is an alloy of iron with carbon and alloying elements. It is stronger than cast iron and is more suitable for building structures and the production of machine parts. Steel is smelted in steelmaking furnaces where the metal is in a liquid state.
There are several methods of making steel.
The main methods of making steel are:
Each method uses different equipment:
Oxygen-converter process
The first method of mass production of liquid steel was the Bessemer process. This method of steel production in an acid lined converter was developed by the Englishman G. Bessemer in 1856-1860. In 1878 S. Thomas developed a similar process in a converter with a basic lining, which was called the Thomas process. The essence of air-blown converter processes (Bessemer and Thomas) is that cast iron poured into the melting unit (converter) is blown from below with air: oxygen contained in the air oxidises impurities of cast iron, as a result of which it turns into steel. In the Thomas process, phosphorus and sulphur are also removed into the main slag. The oxidation process generates heat, which heats the steel to a temperature of about 1600 °C.
Martensky process
The essence of another way to produce steel using the open-hearth process is to conduct melting on the pad of a flame reflection furnace, which is equipped with regenerators for preheating air (sometimes gas). The idea of producing cast steel on the bed of a reflective furnace was suggested by many scientists (e.g. in 1722 by Rheaumeur), but it could not be realised for a long time, because the temperature of the flame of the usual fuel at that time - generator gas - was insufficient to produce liquid steel. In 1856, the Siemens brothers proposed to use the heat of hot exhaust gases for air heating, installing regenerators for this purpose. The principle of heat regeneration was used by Pierre Martin to melt steel. The beginning of the existence of the open-hearth process can be considered as 8 April 1864, when P. Martin at one of the plants in France produced the first smelting.
To smelt steel, a charge consisting of pig iron, scrap, scrap metal and other components is loaded into the open-hearth furnace. Under the action of heat from the torch of burning fuel, the charge is gradually melted. After melting, various additives are introduced into the bath to produce metal of a given composition and temperature. The finished metal is released from the furnace into ladles and poured. Due to its qualities and low cost open-hearth steel has found wide application. Already at the beginning of XX century half of the total world steel production was smelted in open-hearth furnaces.
The first open-hearth furnace in Russia was built in Kaluga province at the Ivano-Sergiev ironworks by S. I. Maltsev in 1866-1867. In 1870 the first smelting operations were carried out in a furnace with a capacity of 2.5 tonnes built by the famous metallurgists A. A. Iznoskov and N. N. Kuznetsov at the Sormovsky plant. Similar furnaces with a larger capacity were later built at other Russian plants on the model of this furnace. The martensky process became the main process in domestic metallurgy. Open-hearth furnaces played a huge role during the Great Patriotic War. The Soviet metallurgists at the Magnitogorsk and Kuznetsk metallurgical plants for the first time in the world practice managed to double the capacity of open-hearth furnaces without their substantial reconstruction, having organised the production of high-quality steel (armour, bearing steel, etc.) at the open-hearth furnaces in operation at that time. At present, due to the expansion of converter and electric steelmaking, the scale of open-hearth steel production is decreasing.
In the main open-hearth furnace it is possible to remelt pig iron and scrap of any composition and in any proportion and to obtain quality steel of any composition (except for high-alloyed steels and alloys, which are obtained in electric furnaces). The composition of the metal charge used depends on the composition of pig iron and scrap and on the consumption of pig iron and scrap per 1 tonne of steel. The ratio between the consumption of pig iron and scrap depends on many conditions.
Electric steelmaking
At present for mass steelmaking electric arc furnaces powered by alternating current, induction furnaces and direct current arc furnaces, which have become widespread in recent years, are used. The share of the latter two types of furnaces in the total volume of smelting is small.
AC arc furnaces are used to smelt steels of electric furnace variety. The main advantage of electric arc furnaces is that for many decades they have been smelting the bulk of high-quality alloyed and high-alloyed steels, which are difficult or impossible to smelt in converters and open-hearth furnaces. Due to the possibility to heat the metal quickly, it is possible to introduce large quantities of alloying additives and to have a reducing atmosphere and oxidation-free slags in the furnace (during the reducing period of melting), which ensures low carbon monoxide emissions of the alloying elements introduced into the furnace. In addition, it is possible to deoxidise the metal more completely than in other furnaces, producing it with a lower content of oxide non-metallic inclusions, as well as to produce steel with a lower sulphur content due to its good removal into the oxidation-free slag. It is also possible to regulate the temperature of the metal smoothly and precisely.
Steel alloying
The process of alloying steel is used to give steel a variety of properties. Alloying is the process of changing the composition of alloys by introducing certain concentrations of additional elements. Depending on their composition and concentration, the composition and properties of the alloy change. The main alloying elements for steel are: chromium (Cr), nickel (Ni), manganese (Mn), silicon (Si), molybdenum (Mo), vanadium (V), boron (B), tungsten (W), titanium (Ti), aluminium (Al), copper (Cu), niobium (Nb), cobalt (Co). Nowadays, there are a large number of steel grades with different alloying elements.
Powder metallurgy
A fundamentally different method of producing ferrous-based alloys is powder metallurgy. Powder metallurgy is based on the use of metal powders with particle sizes ranging from 0.1 µm to 0.5 mm, which are first compressed and then sintered.
Non-ferrous metallurgy
Non-ferrous metallurgy uses a very wide variety of methods to produce non-ferrous metals. Many metals are produced by pyrometallurgical processes involving selective reduction or oxidative smelting, often using sulphur contained in ores as a heat source and chemical reagent. However, a number of metals have been successfully produced by hydrometallurgical processes involving their conversion to soluble compounds and subsequent leaching.
The electrolytic process of aqueous solutions or molten media is often most suitable.
Sometimes metallothermal processes are used, using other metals with a high affinity for oxygen as reducing agents for the metals produced. Other methods such as chemical-thermal, cyanidation and chloride distillation can be mentioned.
Copper production
Scheme of copper refining production (on the example of Uralelectromed copper smelting shop)
1 - blister copper
2 - smelting
3 - reflection furnace
4 - slag removal
5 - copper pouring into anodes
6 - carousel type caster
7 - anode removal machine
8 - anode removal
9 - wagons
10 - transport to electrolysis shop
Two methods of copper extraction from ores and concentrates are known: hydrometallurgical and pyrometallurgical.
The hydrometallurgical method is not widely used in practice. It is used in the processing of poorly oxidised and nugget ores. This method, unlike the pyrometallurgical method, does not allow to extract precious metals along with copper.
Most copper (85-90 %) is produced by pyrometallurgical method from sulphide ores. At the same time, the problem of extracting other valuable associated metals from ores, in addition to copper, is solved in parallel. The pyrometallurgical method of copper production involves several stages. The main stages of this production include:
Aluminium production
Electrolysis baths at Alcoa's Musjoen aluminium smelter in Norway
The main modern method of aluminium production is the electrolytic process, which consists of two stages. The first stage is the production of alumina (Al2O3) from ore raw materials and the second stage is the production of liquid aluminium from alumina by electrolysis.
In world practice, almost all alumina is produced from bauxite mainly by the method of Bayer,[16] an Austrian engineer who worked in Russia. Plants in Russia produce alumina by two methods from different types of ores. From bauxite by the Bayer method and from bauxite and nepheline by sintering. Both of these methods belong to alkaline methods of alumina extraction from ores. The obtained alumina is then used in electrolysis production, which involves the production of aluminium by electrolysis of alumina dissolved in a molten electrolyte. The main component of the electrolyte is cryolite.
In pure cryolite Na3AlF6 (3NaF-AlF3) the ratio of NaF: AlF3 is 3:1. To save energy it is necessary to have this ratio in the range of 2.6-2.8:1 during electrolysis, therefore aluminium fluoride AlF3 is added to the cryolite. In addition, some CaF2, MgF2 and sometimes NaCl are added to the electrolyte to reduce the melting point. The content of the main components in the industrial electrolyte is in the following proportions: Na3AlF6 (75-90) %; AlF3 (5-12) %; MgF2 (2-5) %; CaF2 (2-4) %; Al203 (2-10) %. At increase of Al2O3 content more than 10 % the refractoriness of electrolyte sharply increases, at the content less than 1,3 % the normal mode of electrolysis is disturbed.
Aluminium extracted from electrolysis baths is raw aluminium. It contains metallic (Fe, Si, Cu, Zn, etc.) and non-metallic impurities, as well as gases (hydrogen, oxygen, nitrogen, carbon oxides, sulphur dioxide). Non-metallic impurities are mechanically entrained alumina particles, electrolyte, lining particles, etc. To purify aluminium from mechanically entrained impurities, dissolved gases, as well as from Na, Ca and Mg, it is subjected to chlorination.
Then aluminium is poured into electric mixer furnaces or reflection furnaces, where it is sedimented for 30-45 min. The purpose of this operation is additional purification from non-metallic and gas inclusions and averaging of the composition by mixing aluminium from different baths. The aluminium is then cast on conveyor casting machines to produce aluminium ingots, or on continuous casting machines into ingots for rolling or drawing. In this way, aluminium with a purity of at least 99.8% Al is produced.
Production of other non-ferrous metals
For the production of other non-ferrous metals - lead, tin, zinc, tungsten and molybdenum - use some of the technological methods discussed above, but naturally, the production schemes of these metals and units for their production have their own features.
The material is very interesting. Opens your eyes to the hidden technological processes, thanks to which all the available to mankind technology appears. Without metals, and consequently metallurgy, mankind will sink into the Stone Age.
In the post above I missed an interesting part - the history of metallurgy. I will post it later, otherwise the text becomes too long.
Tomorrow I will try to summarise the most important part. (If I have time).
h ttps:// 4pda.to/2024/05/11/427612/sostavlena_podrobnaya_3d_skhema_chelovecheskogo_mozga_foto/
and there's no references to research.
but it looks like a sprouted potato.