The structure of ferrous metallurgy is determined by a number of diverse industries, which differ greatly in the nature of the products produced in them, in the technology and technology of its production, in the direction and use both in the country itself and outside it. In the structure of the industry, raw materials are extracted (extraction and enrichment of iron ore, its agglomeration, collection of scrap metal and its preparation for remelting); Semi-product redistribution (smelting of pig iron and blast-furnace ferroalloys, steel and its alloys). Particular, decisive importance is the final redistribution – the receipt of rolled and castings of cast iron and steel. Extraction of ores of alloying metals, coking coal, refractories and other auxiliary materials in most countries of the world is referred to other industries.
Progressive shifts in the development of ferrous metallurgy reflects the ratio of steel and cast iron smelting. The growing predominance of steel smelting is the result of the increased demand for rolling in engineering and construction. At the beginning of the century – in 1913 – cast iron was produced in the world 1.04 times more than steel. In 1950, steel was already 1.67 times more than cast iron, as smelting was concentrated in a few industrial countries of the world. The creation of large-scale production of ferrous metals in many new industrial countries in 1950-1995. Led to a decrease in this coefficient to 1.43 (for developed states, it remains high: in the US – 1.87, etc.). In Russia in 1995 the coefficient fell to 1.28 (in the USSR in 1990 it was 1.4). In China, the acute shortage of ferrous metals, especially steel and rolled products from it, stimulated the smelting of foundry iron, which led to a decrease in the coefficient in 1995 to 0.91.
Raw materials base of the world’s iron and steel industry. Iron ore is the main source of raw materials in the industry. In recent decades, the processes of using ore for direct smelting of steel have been mastered, bypassing the stage of obtaining pig iron, which further increased the role of iron ore in all metallurgical production. Iron ore is taken by one of the most massive types of products of the global mining industry: it yields only to coal, oil and natural gas in terms of production. However, the problems of its extraction, enrichment and transportation are more difficult than these energy carriers.
The reserves of explored iron ores in the world are constantly increasing as exploration works are deployed. Thus, the world reserves of explored and developed iron ores in 1922 were estimated at 35.5 billion tons, and the probable reserves of 98.2 billion tons. In the early 1990s, According to various estimates, the total geological reserves varied from 400 to 800 billion tons, of which 150-185 billion tons were spent on reconnaissance. Thus, despite the intensive extraction of iron ore, comprehending in recent years 1 billion tons, their reconnoitered resources in the world Not only did not decrease, but as a whole they increased significantly.
The significance of individual countries and regions of the world in the common geological reserves of iron ore is not the same. More than 28% of them are in the countries of Eastern Europe, mainly in the CIS (Russia, Ukraine), up to 17% in Asia (China, India), 16% in South America (Brazil) and Africa, 13% in North America (USA, Canada) and 5-6% in Western Europe and Australia. The geography of iron ore reserves by regions and countries of the world does not at all coincide with the need for it for a number of states, often completely devoid of developed deposits of this raw material, but having large ferrous metallurgy (Japan, Germany, Republic of Korea, etc.).
The iron content in the ores of different deposits varies widely: the rich ones include ores with an iron content of more than 50%, to the ordinary ones – from 25 to 50% and to the poor – to 25%. In the developed countries of the world, there are few deposits of rich ores: in Western Europe, such limited ore is practically found only in Sweden (60-65% of iron). The vast majority of the region’s mineral resources are poor. Therefore, many countries (Great Britain, Germany, Belgium, etc.) in the 80-ies. Generally stopped their development. Even France, with the largest reserves in the region, in 1993, curtailed the extraction of iron ore. The quality of extracted iron ore in North America also deteriorated. In the United States, the best quality deposits have almost been worked out and now mostly ordinary ore is used (up to 50% of iron). Only Canada and Mexico still have rich ores (61-63% of iron).
The same situation has developed in the countries of Eastern Europe, where the average iron content in extracted ores in Russia and Ukraine is about 40%. In Asia, rich ore is mined in India (up to 63% of iron), and the PRC is forced to develop mainly its poor ores. Such countries with developed ferrous metallurgy, like Japan and the Republic of Korea, do not have their iron ore resources.
All this predetermined the rapid transfer of iron ore production to other countries of different regions of the world. The quality of the ore there is much better (in Brazil up to 68% of iron, in Australia and Venezuela – 64, India – 63, South Africa – 60-65%). They have large reserves for the deployment of a powerful iron ore industry. In 1938, these countries accounted for only 16% of the world’s total iron ore, in 1970 – 35%, in 1995 – more than 55%.
The new scientific and technical methods of enriching the poor and ordinary ores, introduced in Western Europe and the United States, allowed to improve the quality of the product. Thus, the agglomeration processes involved fine ore in circulation and made them suitable for a high-power domain. But the ore agglomerate is low-transportable and manufactured only in the areas of metallurgy. Much more important for the enrichment of all types of ore was the development of the production of iron ore pellets with a metal content of up to 65-70%. They are distinguished by high transportability and, in addition to the blast furnace process, have found a new field of application – in direct iron reduction. This led to the transition to a broad distribution, especially for exports.
In the geography of the iron ore industry of the world in the XX century. There have been cardinal shifts. Up to the Second World War, Western Europe remained the leading region in the extraction of iron ore: in 1913 – 55%, in 1938 – 40% (North America, respectively, 35 and 20%). After the Second World War in 1950, North America gave 43% of the world’s iron ore (Western Europe 30%). In the 70-80-ies. Three regions came forward: South America, Asia and Eastern Europe with a share in the world production of each of them from 20 to 30%, as well as Australia. Their leadership was preserved until 1995. Western Europe and North America collect iron ore less than one Australia. Even greater changes occurred in the extraction of ore by country.
An increasingly important type of raw material is scrap of ferrous metals. Each ton of scrap saves about the same amount of cast iron and, respectively, necessary for its production of iron ore and coke. The metal fund of the national economy of the developed countries is huge and amounts to hundreds of millions and even billions of tons. Its sources are amortization scrap (scrapping machines, equipment, buildings, etc.); Industrial scrap (metalworking waste) and recycled scrap (waste steel casting). The problem of the formation of scrap resources (collection, preparation for remelting) is one of the main tasks of the world’s metallurgy.
The global scrap market is determined within each country by available resources, depending on the level of development of the economy. These scrap resources are very different in individual countries, but in general they are very large. Requirements for scrap of ferrous metals in the world in 1995 reached 385 million tons. Of this secondary raw materials, 40% of steel was smelted in all countries. The benefits of scrap processing in electric arc furnaces and in oxygen converters increase the demand for it. Therefore, a relatively limited amount of scrap is involved in foreign trade: about 5-7% of its resources.
Production of metallurgical coke. Coke, obtained from coking coal, is a fuel and a reducing agent for iron ore during the smelting of cast iron. Coke is the first cost component in the domain process. It is supplied by coke-chemical shops in the metallurgical or in the fuel industry. Despite the emergence of a new direction for the production of steel in no-coke (or without-domain) metallurgy, the absolute role of coke in the world does not decrease. Its production is forced to create for its metallurgical industry even devoid of coking coal resources of the country, importing them in large quantities.
The achievements of the NTP contributed to a sharp decrease in the consumption rates of coke for the smelting of cast iron. Thus, in 1938 the world average coke consumption per 1 ton of pig iron was more than 1.68 tons, by 1960 it was reduced to 1.09 tons, and in 1990 was just 0.66 tons. Improvement of the quality of iron ore , Improvement of technology and techniques of smelting of pig iron allowed to reduce specific expenses of coke more than twice. Therefore, the combustion of coke from the 70’s. In the world it stabilized at the level of 350-360 million tons, despite the growth of pig iron smelting. In the US and a number of countries in Western Europe, the production of coke even decreased by 2-3 times;
Placement of coke production for 1938-1995. Has undergone great changes. In pre-war 1938, Western Europe, which had coking coal resources, was the world’s leading producer of coke, yielding more than half (55%). After World War II, primacy passed to coal-rich North America: in 1950, 40% of coke in the world. In 1990, Asia became the leader in coke production, 43%, and in 1995 its share increased to 55%. Significant shifts in the role of producers of coke occurred in individual countries: before World War II Germany was separated, after the war until 1961, the USA, then until 1991 – the USSR, and after 1991 – the PRC.
Alloying metals are necessary for the production of ferroalloys, low-alloyed (containing up to 2.5% alloying metals), medium-alloyed (2.5-10%) and high-alloy (more than 10%) steels. In general, compared with the basic metal – iron, the use of alloying metals is small. Among them, only manganese, chrome and nickel produce in the world in quantities of more than 1 million tons each. The remaining metals of this group are used in much smaller quantities, sometimes only hundreds of kilograms. Therefore, the volumes of ore extraction of alloying metals and the production of metals themselves for the deployment of ferrous metallurgy have almost no effect.
Most of the leading states for the production of ferrous metallurgy are not provided with all kinds of alloying metals, and sometimes, like Japan, do not have them. As a rule, they have in sufficient quantities only some of them:
Brazil and Ukraine – manganese, Russia and Canada – nickel, Brazil and India – chromium, China – tungsten, USA – molybdenum. Dependence on imports of chromium, manganese and cobalt or raw materials for their production in Western Europe is 100%, nickel 99, tungsten 70%. In the USA, it reaches 70% in nickel and tungsten, up to chromium 75, cobalt 95 and manganese 100%. Very high availability of these and some other alloying metals of Russia and China, they are, along with the countries of Africa and South America, exporters of a number of alloying metals.
Production of metallurgical complex. Melting of cast iron – an alloy of iron with carbon – the first stage of direct production of metal in the industry. Of the smelted iron in blast furnaces, about half of all steel in the world is produced. Depending on the further use in blast furnaces, smelting (white) cast iron is used, which is used for steel conversion. He accounts for the overwhelming majority of pig iron (over 85%). Foundry (gray) cast iron is an important structural metal, which is used for making all kinds of shaped castings. Products of blast-furnace production are also some ferroalloys, for example, cast iron with a high content of silicon, manganese (ferrosilicon, ferromanganese, etc.).
Blast furnace process – the most material-intensive in the main metallurgical cycle. For smelting 1 ton of pig iron, at least 3 tons of iron ore raw materials, fuel, limestone, up to 30 m3 of water, natural gas, oxygen are consumed. To increase the efficiency of iron production, to reduce the cost of materials and fuel, the use of high-quality iron ore has always been and remains a priority. The economic effect is also achieved by increasing the volume of blast furnaces. This allows you to significantly reduce investment in the construction of blast furnaces, reduce the cost of cast iron, improve the technological process, reduce fuel costs. During the postwar years, the maximum volume of the domain in the world increased from 1500 to 5000 m3. The modern blast furnace is able to produce 4-4.5 million tons of pig iron in one year, which is comparable to cast iron smelting in one of such countries as Austria, Turkey or Mexico.
Complex economic, and especially environmental problems caused large changes in the geography of blast-furnace production. Along with local shifts in the location of factories with blast-furnace workshops (their relocation from the old regions of ferrous metallurgy along the way of import of raw materials to the coastal points of coastal countries), major interregional changes also took place. The main result of such migration processes in certain parts of the world is the diminishing role of the old industrialized countries in obtaining pig iron. For the years 1950-1995. The total share of Western Europe and North America decreased (despite the organization of this production in the new countries of these regions) from 75 to 31% in the world.
Cast iron smelting in the 60-70-ies. Increasingly grew in the process of industrialization of the countries of Eastern Europe, and in the 80-90s. in Asia. The total share of these regions in the world for the same years increased from 20 to 60%. This led to global changes in the geography of ferrous metallurgy. Radical changes occurred in the smelting of pig iron for individual countries: in 1970-1990. The leader was the USSR, and in the 90’s. It became the PRC. Against the background of these cardinal shifts, the role of the rest of the world’s regions – Africa, South America and Australia – changed little. For 45 years, their share in the production of pig iron in the world has increased from only 3.6 to 9%, although they account for 31% of the world’s iron ore and more than 10% of coking coals.
The production of steel is an intermediate stage of the metallurgical cycle. Steel is just a semi-product, intended for further conversion into rental, going directly to other branches of the economy. Each of the consumers presents its technical requirements for the quality of rolling products from different grades of steel. There are ordinary (ordinary), high-quality and high-quality steel. Technical properties of steel are determined by the content of alloying additives and carbon in it: low-carbon, high-carbon (instrumental). The volumes of their production are different, but the output of quality steels is growing steadily. Thus, the world production of stainless steel for 1960-1995. Increased from 2 to 15 million tons, i.e. Grew 3.5 times faster than all steel.