The history of mankind has more than one thousand years. Throughout the entire period of the existence of our race, steady technological progress has been noted, an important role in which was played by the ability of a person to handle metal, create and mine it. Therefore, it is quite logical that metallurgy is something without which it is impossible to imagine our life, the normal fulfillment of work responsibilities and much more.
Definition
First of all, it is worthwhile to understand how the modern sphere of production is called scientifically, from a technical point of view.
So, metallurgy is a branch of science and technology that covers the process of obtaining various metals from ore or other materials, as well as all processes related to the transformation of the chemical composition, properties and structure of alloys.
Structure
Today, metallurgy is a powerful industry. In addition, it is an extensive concept that includes:
- Direct metal production.
- Processing of metal products both in hot and cold form.
- Welding.
- Application of various metal coatings.
- The branch of science is materials science. This direction in the theoretical study of physicochemical processes focuses on the knowledge of the behavior of metals, alloys and intermetallic compounds.
Varieties
All over the world there are two main branches of metallurgy - ferrous and non-ferrous. This gradation has developed historically.
Iron and steel industry is the processing of iron and all alloys in which it is present. Also, this industry involves the extraction from the bowels of the earth and the subsequent beneficiation of ferrous ores , steel and iron foundries, rolling stocks, and the production of ferroalloys.
Non-ferrous metallurgy is considered to work with ore of any metal except iron. By the way, non-ferrous metals are conventionally divided into two large groups:
- Heavy (nickel, tin, lead, copper).
- Light (titanium, magnesium, aluminum).
Scientific solutions
Undoubtedly, metallurgy is an activity that requires the introduction of innovative technologies. In this regard, many countries of our planet are actively conducting research work, the purpose of which is to study and put into practice a wide variety of microorganisms that would help solve, for example, such an urgent issue as wastewater treatment, which is an indispensable component of metallurgical production. In addition, processes such as biological oxidation, precipitation, sorption and others have already become a reality.
Process separation
Metallurgy plants can be conditionally classified as two main groups:
- pyrometallurgy, where processes occur at very high temperatures (smelting, firing);
- hydrometallurgy, which is the extraction of metals from ores using water and other aqueous solutions using chemical reagents.
The principle of choosing the place of construction of the metallurgical plant
In order to understand on the basis of what conclusions the decision is made to build an enterprise in a particular place, it is worth considering the main factors in the location of metallurgy.
In particular, if the issue concerns the deployment of a non-ferrous metallurgy plant, then criteria such as:
- The availability of energy resources. Production associated with the processing of light non-ferrous metals requires a tremendous amount of electrical energy. Therefore, such enterprises are being built as close as possible to hydroelectric power plants.
- The required amount of raw materials. Of course, the closer the ore deposits are, the better, respectively.
- Environmental factor. Unfortunately, the countries of the post-Soviet space cannot be assigned to the category where metallurgy enterprises are environmentally friendly.
Thus, the location of metallurgy is a complex issue, the solution of which should be given the closest attention, taking into account all sorts of requirements and nuances.
To form the most detailed picture in the description of metal processing, it is important to indicate the key areas of this production.
Iron and steel industry incorporate several so-called redistributions. Among them: sinter, steel, rolling. Let's consider each of them in more detail.
Blast furnace production
It is at this stage that iron is released directly from the ore. This happens in a blast furnace and at temperatures above 1000 degrees Celsius. Thus, iron is smelted. Its properties will directly depend on the course of the melting process. By controlling the melting of the ore, one can ultimately obtain one of two types of cast iron: pig iron (used in the future for steel production) and foundry (cast iron billets are cast from it).
Steel production
By combining iron with carbon and, if necessary, with various alloying elements, steel is finally obtained. There are enough methods for smelting it. We especially note the oxygen-converter and electrofusion, which are the most modern and highly productive.
Converter smelting is characterized by its transience and the resulting steel with the required chemical composition. The process is based on blowing liquid metal with oxygen through a lance, as a result of which the iron is oxidized and transformed into steel.
The electric steelmaking method is the most effective. Thanks to the use of arc furnaces, the highest quality alloyed steel grades can be smelted. In such units, the heating of the metal loaded in them occurs very quickly, while it is possible to add the required number of alloying elements. In addition, the steel obtained by this method has a low content of non-metallic inclusions, sulfur and phosphorus.
Alloying
This process consists in changing the composition of the steel by introducing into it the calculated concentrations of auxiliary elements to subsequently give it certain properties. Among the most commonly used alloying components are: manganese, titanium, cobalt, tungsten, aluminum.
Rent
Many metallurgy plants incorporate a rolling group of workshops. They produce both semi-finished products and already completely finished products. The essence of the process is the passage of metal in the gap between the rolling rolls of the rolling mill rotating in opposite directions. Moreover, the key point is that the distance between the rolls should be less than the thickness of the blank. Due to this, the metal is drawn into the lumen, moves and eventually deforms to the specified parameters.
After each pass, the gap between the rolls is reduced. An important point - often the metal is not plastic enough in the cold state. And therefore, for processing it is preheated to the required temperature.
Recycling
In modern conditions, the market for the consumption of recyclable materials of both ferrous and non-ferrous metals is steadily developing. This is largely due to the fact that ore resources, unfortunately, are not renewable. Each year of their production significantly reduces reserves. Considering the fact that the demand for metal products in mechanical engineering, construction, aircraft building, shipbuilding and other sectors of the national economy is steadily growing, it seems quite reasonable to develop a processing of parts and products that have already exhausted their resources.
It is safe to say that the development of metallurgy is to some extent also explained by the positive dynamics of the industry segment - the use of recycled materials. At the same time, both large and small companies are engaged in the processing of scrap metal.
World trends in the development of metallurgy
In recent years, there has been a clear increase in the output of rolled metal, steel and cast iron. This is largely due to the real expansion of China, which has become one of the leading planetary players in the metallurgical production market.
At the same time, various factors of metallurgy allowed the Celestial Empire to win almost 60% of the entire world market. The remaining ten major producers were: Japan (8%), India and the United States of America (6%), Russia and South Korea (5%), Germany (3%), Turkey, Taiwan, Brazil (2%).
If we consider separately 2015, then there is a tendency for a decrease in the activity of metal producers. Moreover, the largest decline was noted in Ukraine, where the result was recorded, which is 29.8% lower than last year.
New technologies in metallurgy
Like any other industry, metallurgy is simply unthinkable without the development and implementation of innovative developments in practice.
So, employees of the Nizhny Novgorod State University have developed and began to put into practice new nanostructured wear-resistant hard alloys based on tungsten carbide. The main direction of application of the innovation is the production of modern metalworking tools.
In addition, the grate drum with a special ball nozzle was modernized in Russia in order to create a new technology for processing liquid slag. This event was carried out on the basis of a state order of the Ministry of Education and Science. Such a step fully paid off, since its results ultimately exceeded all expectations.
The largest metallurgical enterprises in the world
International ratings claim that the leading metal producers on the planet are:
- Arcelor Mittal is a company headquartered in Luxembourg. Its share is 10% of the total global steel production. In Russia, the company owns the Berezovskaya, Pervomaiskaya, Anzherskaya mines, as well as Severstal-group.
- Hebei Iron & Steel is a giant from China. It is wholly owned by the state. In addition to production, the company is engaged in the extraction of raw materials, its transportation and research. The company’s factories use exclusively new developments, and the most modern technological lines, which allowed the Chinese to learn how to produce ultra-thin steel plates and ultra-thin cold-rolled sheets.
- Nippon Steel is a representative of Japan. The management of the company, which began its work back in 1957, seeks to merge with another company called Sumitomo Metal Industries. According to experts, such a merger will allow the Japanese to quickly become the first in the world, ahead of all their competitors.