THE STEELMAKER'S
KITCHEN
 
Dear Friends,

This book is about mining and steelmaking. It is both unusual and simple. You won't find kilometres of formulas and trainloads of technical terms here. Just what's most important, written in a way that you can understand. Few words and lots of pictures. Funny stories and interesting facts. I want everyone, even people who have never seen inside a factory, to be able to understand how everything works in the steelmaker's kitchen. Sort of a basic introduction. By the way, this book compares the whole process of mining ore and making steel with cooking. Something that is familiar and understandable to everyone. I hope you get as much pleasure from this book as from delicious food.

Stone, bronze, iron. The world has gone through different stages of development, from the simplest metals to complex alloys. Today, a different element rules the periodic table: silicon. Artificial intelligence can already match human intellect. Soon, our entire lives will be digital. None of this would be possible without steel — you can't even make a computer without it. I think steel is the ideal material and has changed our world. It can be recycled an infinite number of times. Steel is eternal.

I grew up in a family of steelmakers. I saw red-hot pig iron for the first time when I was three years old. To this day, I still remember that spectacle and my emotions at that moment. Now, I lead Metinvest Group, the largest steelmaking company in Ukraine and one of the largest in the world. This is my dream job. Creating useful things drives me, makes me proud and offers a sense of personal fulfilment.

There is much to see in this book: deep mines, giant quarries, fire-breathing furnaces. You will learn how solid rock is turned into planes, bridges and skyscrapers — everything that surrounds us every day.

Yuriy Ryzhenkov
Chief Executive Officer
Metinvest Group
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STEEL
an alloy of iron and carbon with a carbon content of less than 2.14%. Steel is smelted using pig iron, flux and ferroalloys.
It is impossible to imagine the modern world without steel. It is everywhere. In bridges and skyscrapers, airplanes and ships, computers and safety pins. The list goes on. Thanks to this material, we have new opportunities — to rise higher, to move faster, to live more interesting and comfortable lives. All because of steel's special properties. It is both durable and flexible. It can also be recycled an infinite number of times. Who knows, today you are riding in a car and in a few years, it could become part of a spaceship.

Each day, from morning to night, we use things made of steel. Let's do an experiment and try to count how many steel gadgets surround us throughout the day. Look at the page on the right. Who has more, the man or the woman?
IRON'S MYSTERIOUS ORIGINS
Steel is an alloy of iron and carbon. The origins of one of the most common metals in the Earth's core remain a mystery. Legend has it that the first iron fell from the sky. Ancient people learned to make arrowheads, spears, shields, swords and decorations from giant meteorites that landed on the planet. The Sumerians (the people who used to live in parts of the Middle East) and Egyptians are delieved to be the first people who mastered the metal. This happened in the fourth millennium BC.

It took nearly three thousand years for items made of iron to come into common use. The stone, copper and bronze ages made way for the iron age. Iron from meteorites was rare, and products made from it were more valuable than gold. The people who had mastered its secrets were in no hurry to share them. Ornaments and weapons of such "heavenly" origin were owned mostly by the nobility.

The first mentions of a method for making iron from ore — the charcoal-hearth process — date to the second millennium BC. Iron that was obtained from ore and charcoal, at first in closed pits and then in clay ovens, resembled dough. To get rid of the slag, it was hand-forged using strong blows from a hammer.

FIG. 1 STEEL IN OUR LIVES
Iron casting was not invented until the late Middle Ages with the advent of blast furnaces, in which pig iron is smelted from iron ore. Pig iron is also an alloy of iron and carbon but is more brittle in its solid state. It is used to make cars, cooking pans and bathtubs, and is also a semi-finished product used to make steel. In ancient times, pig iron was considered worthless because of how brittle it was. Later, they discovered that when re-smelted in a furnace, pig iron becomes good-quality steel. This principle was popular for many centuries and remains so today.

Iron quickly became the main material used to make weapons and agricultural tools. The possession of ferrous metals determined the outcome of battles, the course of history and the pace of technological progress.

In 1864, a French engineer named Pierre-Émile Martin took out a licence on the open hearth furnace, first developed by Carl Wilhelm Siemens, and used it to smelt iron and scrap metal into steel. This invention made it possible, for the first time in history, to obtain high-quality liquid steel. The Siemens-Martin's process became the primary method of steel production until the 1970s. Today, Siemens-Martin's open-hearth furnaces are no longer used, having been replaced by oxygen converters and electric-arc furnaces.

One of the world's largest meteorites fell in the Sikhote-Alin mountains
of Russia's Primorsky region in February 1947.
STEEL AROUND THE WORLD AND IN UKRAINE
ТОP-15 COUNTRIES — STEEL PRODUCERS
1 China
2 Japan
3 India
4 USA
5 Russia
6 South Korea
7 Germany
8 Тurkey
9 Brazil
10 Italy
11 Taiwan
12 Ukraine
13 Iran
14 Mexico
15 France

Global steel production is steadily growing and reached almost 1.8 billion tonnes in 2018. Around half of this volume is smelted in China. Other major steelmaking countries include Japan, India, the US, Russia, South Korea, Germany, Turkey, Italy, Taiwan and Ukraine.

Ukraine's mining and metals sector unites companies in ferrous and non-ferrous metallurgy, mining and processing plants, ferroalloy and coke plants, and companies that make metal products. Steelmaking accounts for a quarter of the country's industry and foreign currency revenue, as well as up to 10% of government budget revenues.

Ukraine has three main steelmaking regions: Donetsk, Priazovsk and Pridneprovsk. They have large concentrations of fuel (mostly coal) and iron ore, and they also produce iron ore raw materials and metal products. Mining and processing plants, known as GOKs in Ukraine, are located mainly in the city of Kryvyi Rih, including Sukha Balka, Ingulets GOK, Northern GOK, Southern GOK and Central GOK. The steelmaking industry is located in Mariupol (Ilyich Steel and Azovstal), Zaporizhia (Zaporizhstal, Dniprospetsstal and Zaporizhia Ferroalloy Plant), Dnipro (Dniprovsky Steel Plant and Interpipe Steel), Kryvyi Rih (ArcelorMittal Kryvyi Rih) and other cities. The country has several main steelmakers. The largest is Metinvest Group. It is a vertically integrated holding. Put simply, the Group's companies produce all the components that are needed to make steel products. The quarries of the four mining and processing plants in Kryvyi Rih mine iron ore, the coke plants in Avdiivka and Zaporizhia make coke, and steel is made at Ilyich Steel and Azovstal in Mariupol, as well as at Zaporizhstal. The Group has plants in Bulgaria, the UK and Italy that only make finished products from its feedstock. Metinvest has its own sales network that sells its metal products in more than 100 countries worldwide.

Miners and smelters always work together. This is how the steelmaker's kitchen works. The comparison with cooking here is not accidental. After all, people cannot live without food, just like the world cannot live without steel. To understand the intricacies of cooking this dish, we look at each shelf in the steelmaker's kitchen and analyse every ingredient. Are you ready to be a chef? Then let's go!
22 billion tonnes of steel have been recycled globally since 1900 as steel is 100% recyclable
Trametal, plant of Metinvest Group in Italy
FIG. 2 MINING AND SMELTING
C H A R T E R 1
Metal production is a technologically complex and lengthy process. The end product depends on many factors. Preparation of raw materials plays an important role here. Just like in your kitchen at home, we need the right ingredients of the finest quality to cook such delicious dishes as pig iron and steel. One of them is coking coal. First, it is mined, and then coke is made, which becomes the fuel and chemical reagent for pig iron production.

There are many varieties of coal, called grades. They have different properties and fields of application. Only special types of metallurgical coal grades are used in the steelmaking industry. It is distinguished by its special energy intensity, capability of obtaining flexible state and, under special conditions, sintering1. This is not a suitable fuel for home heating, but it is ideal for the production of blast-furnace coke.
Up to 7 minutes it takes miners to descend
into Ukrainian mineshafts
MINING
The coal mining process requires physical strength. Whoever has held a shovelb in their hands knows that digging up even a bucket of potatoes is no easy task. While powerful combines have been introduced to make the work easier over the years, a miner's job is still considered one of the most difficult of all.

There are two ways to mine for coal — open-pit and shaft mining. Open-pitining is used in shallow coal beds up to 100 metres deep. In Ukraine, coal seams can run more than 1,500 metres deep. In such cases, underground shaft mining is used. The seams are developed along longwalls, which resemble long underground tunnels.

The main technological processes in mining include excavating the coal from the mining face (the main place where work takes place), moving it along the longwall and loading the raw materials onto a vehicle. For safety, the face is ventilated and cleaned of the gases that are released from the coal seams. The rock pressure must be watched closely during the work. To keep the voids formed after the coal is mined from collapsing, a special type of support called lining is erected.

Excavating coal consists of blasting and loading the mineral. The coal is then chopped with a machine called an excavator that gets its name from the kind of work it does. The mined rock is loaded onto a drag conveyor, transported through the mine and lifted in skip hoists (steel boxes) to the surface.

1,546 metres — the deepest coal mine in
the world is located in Ukraine
FIG. 3 COAL MINING
COAL ENRICHMENT
The hard coal that is mined has many impurities. They reduce the raw material quality and, when burned, generate lower temperatures. To remove waste material from the coal, it is enriched, or cleaned. During this process, the mineral content is reduced and the coal is also sorted into grades according to grain size.

The first stage is grizzly screening, or sorting by size. This is done using grizzlies, which are special machines with vibrating screens: the coal passes over screens with different sized holes and is sorted into groups. The screens make a distinctive sound, not unlike a grizzly bear, which is how the machines got their name.

The second stage is enrichment. The most common type of coal enrichment is a "wet" cleaning process called coal washing (also known as flotation, from the French word flotter — float). Coal and impurities have different densities. In water, they separate from each other. This happens in gravitational enrichment machines called jigging machines. Coal is placed on a screen through which water gradually rises. The heavy rock sinks and the light coal floats. The impurities (from 10% to 15%) are transported to the dump, while the concentrate, which is the coal that has already been enriched, is sent to the coking plant.

Another type of coal washing is foam flotation. During this process, coal that has been treated with a reagent floats to the surface of a tank along with air particles. The final step of coal washing is dehydration. The coal passes through a filter and is dried.

By the way, just like there is a wet cleaning process, there is also a dry cleaning process! It uses cyclones that work based on centrifugal force. When the machine rotates at high speeds, the coal is collected in the upper part of the cyclone and the waste is collected in the lower part.

The coke plant is waiting for the coal concentrate - an irreplaceable product of the highest quality. So, we are ready to "cook" the first dishes in our steelmaker's kitchen. What do you think about our cake? Not just any old cake, a coke cake!

C H A R T E R 2
COKE
(from the late Middle English word colke) — a high-quality, smokeless fuel that is required for smelting pig iron in a blast furnace. Coke is made from specific types of hard coal that are heated in an airtight environment.
We have mined coal and enriched it to obtain concentrate. Now we are climbing out of the depths of the mine and moving straight to the coke production plant. It is going to be hot here!

To make blast-furnace coke, we will need coking coal and a coke oven. Most often, several types of coal are used. The special mix of coal that is created is called the charge.

In steelmaking, coke (from the late Middle English word colke) is a hard, porous, grey product. It is obtained by heating hard coal to 1,000° C in an airtight environment. This process is called coking.

Coke is a high-quality smokeless fuel used to make pig iron in a blast furnace. It is used not only to melt the charge but also to recover the iron from the ore. Coke is used in rather diverse ways: at foundries, in the chemical and ferroalloy industries, and even for heating homes.

Avdiivka Coke is Europe's largest coke plant. It makes 31 different products for companies in Ukraine and around the world.

Ukraine's largest coke plants also include Zaporizhia Coke, Dniprovsky Coke, Yuzhkoks and Kharkiv Coke.

The steelmakers ArcelorMittal Kryvyi Rih and Azovstal also have their own coke production facilities.

Avdiivka Coke Plant
1,546 metres — the deepest coal mine in
the world is located in Ukraine
PREPARATION
Now we have the ingredients we need to bake our cake. The product we make in a coke oven is actually called a coke cake.

After being mined and processed, coking coal is sent to coking plants to be made into coke. The first step in baking our cake is crushing coal to make flour. Or rather, a coal preparation.

The flour needs to be of the highest grade and finely ground. This makes it possible to obtain uniform, durable coke. Each grain of impurity reduces the quality of the coke, violates its homogeneity and helps cracks to form, which will impede the chemical reactions during pig iron production.

Andrey Golovchenko, refractory man at Avdiivka Coke
PIG IRON
— an alloy of iron and carbon with a carbon content of more than 2.14%. To make pig iron, iron ore, coke and flux are smelted at a high temperature. Pig iron is used to make products (pans, bathtubs and manhole covers) or is smelted further into steel.
COKING
Coke cakes are baked in special ovens called coke ovens, which are joined together to form coke-oven batteries. Each coke-oven battery can contain 45-70 ovens.

Just like in the kitchen at home, the only difference is the size of the oven and the baking temperature. Coke ovens are horizontal, rectangular chambers that are heated through their side walls. Coal is loaded on top. The transformation takes place in an airtight environment at a temperature above 1,000° C. Cake batter usually consists of more than just flour. Similarly, in most cases, coke is made not from one type of coal, but from a charge. Like an ordinary cake, a coke cake bakes from the outer edges to the middle. The coking process takes 14-16 hours and is divided into several stages, depending on the heating temperature.

The first stage is drying. Coal is heated to 200° C and moisture evaporates from it. After further heating to 350° C (the second stage), the coal begins to soften. A film of bitumen, a residual tar-like by-product of coal processing, appears on the coal grains. During the third stage, at a temperature of 500° C, the coal becomes flexible. Starting at 600° C, as the cake is just beginning to bake, semi-coke is formed. Then, by 1,050° C, the process of forming solid coke is completed.

Each stage of baking coke is accompanied by complicated chemical processes. When sintering coke, a valuable by-product called coke-oven gas is formed. It can be refined into tar, ammonia, sulphuric acid, benzene, phenolates and light pyridine bases. While not everyone can remember the formulas of these substances, everyone has seen products made from them. These substances are used to make fertilisers, varnishes and paints for refrigerators and cars, naphthalene, tar for road construction and much more.

Europe's largest — coke plant, Avdiivka Coke,
is located in Ukraine
The hot coke cake becomes crumbly. It is taken out of the oven with the help of a door lifter and coke pusher and placed into a special railcar. To keep the coke from burning outside the oven, it is extinguished. There are two ways to cool it: wet cooling, where the coke is doused with water; and dry cooling, where the temperature is reduced by blowing circulation gas.

The coke is then sifted and sorted by chunk size. The largest chunks are blast-furnace coke, the medium chunks are shot coke and the remaining chunks are coke fines. The large chunks are used in blast furnaces to smelt pig iron, the medium chunks are used as fuel in the ferroalloy industry and the fines are used in sinter production.

Coke is a finished product used for smelting pig iron. One more irreplaceable ingredient is ore. To get it, we will go to the quarry.

FIG. 4 COKE PRODUCTION
C H A R T E R 3
Imagine that you are standing at the edge of an open-pit iron ore mine. Its scale and depth are mindboggling. The huge dump trucks winding up serpentine roads seem like toys in comparison. It is hard to believe that this was made by human hands.

Open-pit mines resemble giant craters, picturesque mountain dumps and deep pits. The world's largest mine is Bingham Canyon, in the US, which has a depth of 1.2 kilometres, a diameter of more than 4 kilometres and an area of 7.7 square kilometres. This is enough space to fit a city or even a small state.

In Ukraine, most iron ore mines are concentrated in Kryvyi Rih. Ore is mined there at the open pits of mining and processing plants, which are known as GOKS in Ukraine — Northern GOK, Ingulets GOK, Central GOK and Southern GOK — as well as in the mines of Sukha Balka and Kryvyi Rih Iron Ore Plant. By the way, Europe's largest open-pit mine is operated by Ingulets GOK. It is 426 metres deep and 38 million tonnes of ore are extracted from its depths each year. There is a large iron ore deposit in Horishni Plavni (its open-pit mines are operated by Poltava GOK).

The world has around 170 billion tonnes of proven iron ore reserves. Ukraine ranks in the global top 10 in terms of iron reserves. Our deposits contain 6.5 billion tonnes of ore.

Iron ore is the primary raw material used in steel production. The resulting rock mass is enriched to obtain iron ore, a concentrate from which pellets and sinter are made. Without them, it would be impossible to smelt pig iron.

Raw iron ore is the main component of a wholesome, balanced diet for a blast furnace. Ore, like coke, is part of the charge that is later turned into a pure, "diet" metal.
Blast furnace
— a metallurgical furnace used to smelt pig iron from iron ore, coke and flux.
ORE MINING
DUMP
— a mound formed after mining minerals from the land or disposing of processing plant waste.
Iron ore, like coal, can be mined in open pits and shafts. If the ore lies close to the surface and the ore layer is thick enough, open-pit mining is used. If the ore is buried deep in a thin layer, shaft mining is used. Shaft mining is very similar to coal mining.

There are two stages of open-pit mining. The first is stripping work. To reach the ore, you must remove soil, sand and stone and take them to a dump (a pile of barren rock). The second stage is the actual mining. Solid ore formations are broken up with explosions. Several hundred tonnes of explosives are used at once to do this.

Metinvest's mining and processing plants use environmentally safe explosives that do not contain trinitrotoluene, otherwise known as TNT. This causes less dust and gas to rise into the air.

Next comes the turn of special equipment, including bulldozers, excavators and dump trucks. The blasted rock is heterogenous in form and composition. How it is further processed depends on the size of the rock pieces. Iron ore is crushed and ground, as well as sorted by screening and classification.

The finer the ore is crushed, the better it will be separated from waste rock and various impurities. Once all impurities have been removed, it becomes iron ore concentrate, which is suitable for further processing and smelting into pig iron. In terms of iron content, ore is classified as rich (at least 57% iron) and poor (at least 26%). Enrichment is used to increase the iron concentration. Enriched ore makes blast furnaces operate more efficiently and reduces slag yield and coke consumption while smelting pig iron. To enrich the ore, magnetic separation and flotation are used.

SLAG
— in ferrous metallurgy, slag is a by-product or waste product of metal production. Slag is used to manufacture building materials (bricks and cement), gravel for road construction and fertilisers.
The Hleyevatsky open-pit mine in Kryvyi Rih is
30 times deeper than the Azov Sea. It stretches
4 km in length and covers an area of nearly 500 hectares, which is equivalent to the size of several small villages
ELECTRIC DUMP TRUCK

Huge dump trucks transport ore at open-pit mines. This beauty is a 220-tonne BelAZ 75306. It is currently the largest type of dump truck in Ukraine. It works at Ingulets GOK. This is an electric hybrid vehicle. Its 2,300 horsepower diesel engine powers electric motors that transmit torque to the wheels.

In one run, this giant could carry up to 40 elephants. In three shifts, it could move the Eiffel Tower.

ENRICHMENT
The first enrichment method is used most frequently in industrial settings: crushed ore is passed through a magnetic field. Do you remember experimenting with magnets as a child — how a horseshoe magnet attracted all sorts of things made of iron? That is how this method works. A magnetic separator consists of a fixed magnet and a rotating drum. Ore and water are fed into the outer surface of the drum. The iron particles are attracted to the surface of the rotating drum and can only be washed off it outside the magnetic field, which helps to separate the concentrate.

In the flotation method, crushed ore is processed in a flotation machine by blowing air through the pulp (a mix of ore and liquid) in the presence of starch, soda, pine oil and other flotation reagents. The iron particles remain in the flotation machine's chamber while the waste rock collects in the foam.

As moisture makes further processing more energy-intensive, after enrichment, the concentrate needs to be dehydrated. Vacuum filters are used for this. Wet concentrate is filtered using discs covered on both sides by a special cloth, the precipitate is dried under a vacuum and the liquid is removed. After dehydration, we receive iron ore concentrate that is ready to be shipped to the consumer. It looks like a black and slightly moist sand.

5,000,000,000
pellets are made on average each day at Metinvest's mining and processing plants, which is 10 times more than the daily number of Twitter messages
PELLETS
Iron ore concentrate is used to produce sinter and pellets, which are needed to smelt pig iron in a blast furnace. Sinter will be discussed in the following chapter. Pellets are strong, spherical granules with a diameter of 7-28 millimetres. Their iron content reaches 67.5%, much higher than in ore.

To make pellets, you need to prepare the charge. This is a mixture of concentrate and additives — flux and bentonite clay. All the ingredients need to be thoroughly mixed until homogenous, then moistened and rolled into pellets in rotating bowls or pelletising drums (granulators).

Next, the raw pellets need to be strengthened: dried at a temperature of 300-600° C, heated, baked (1,200-1,300° C) and cooled. This allows the pellets to be transported great distances and stored for long periods of time. These roperties are especially important for steelmakers, which are located far from the mining and processing plants.

In this chapter, we mined ore, enriched it, turned it into iron ore concentrate and even made pellets. Just a couple more ingredients and we will be at the threshold of the steelmaker's kitchen.

FIG. 5 MINING PRODUCTION
C H A R T E R 4
SINTER
(also known as agglomerate, from the Latin word agglomeratus — collected or formed into a mass) — an iron ore powder or dust that has been caked into porous chunks. In addition to iron, sinter also contains coke and flux. Sinter is a raw material used to make pig iron in blast furnaces.
RETURNS
— the fine sinter and un-caked furnace charge that is re-used in the sintering process.
On the threshold of the steelmaker's kitchen we find the sinter plant. Here, the preparation of iron ore raw materials for the production of pig iron is completed — sinter is produced. The plant has a place to store all the ingredients, equipment for grinding and preparation, as well as workshops where raw materials are received, processed and shipped in the form of finished products.

Sinter, which is also known as agglomerate (from the Latin word agglomeratus — collected or formed into a mass), is fine ore that has caked into porous chunks. After enrichment, iron ore turns into concentrate, a dust that could blow away in the wind. That is why concentrate is made into pellets or caked into chunks at a sinter plant. The concentrate is added into huge bowls, mixed with various additives with a special mixer and heated up strongly. The necessary for sintering temperature is kept with hot air. This process is called agglomeration and serves for turning the iron ore raw material into a semi-finished product necessary for the production of pig iron. Moreover, the quality of the metal directly depends on the quality of the sinter.

To make sinter, we need the following products: sinter ore (iron ore fines), iron ore concentrate, fluxing limestone and coke fines or thermal coal. We will also need an ingredient we have not seen before — return sinter fines, or simply returns. This is fine sinter and un-caked furnace charge. They are obtained by sifting the finished sinter. Using returns improves the sintering process. Steelmaking wastes are also used: slag, tailings and blast-furnace dust.

The central component in this process is ore. It is mixed with the returns and sintered with the other elements of the charge. The ingredients enter receiving bunkers at the ore yard, where raw materials are delivered by rail or in dump trucks. From the bunkers, materials are fed in a certain ratio into mixing drums. They look like a blender. The charge is mixed and moistened in special machines. It gradually clumps together, becoming grainy and crumbly, which increases its gas permeability. That means that it is easier for gas to combine with the fuel particles, allowing the mass to sinter evenly.

In cooking, dough can be placed on parchment to keep from sticking to the pan. The same thing happens with the sinter: a bed for the charge is made from returns or large pieces of charge remaining from the previous batch of sinter.

The oven is a special sintering furnace known as a sinter machine. Here, like in a normal oven, there is also a grill — a grate on which the sinter ore and fuel are placed. At steelmaking plants, most sinter machines are conveyors. This is a continuous chain of sintering arts with grated bottoms.

The sintering process begins at the sinter machine's hearth, which burns a mixture of natural gas and air. The temperature in the furnace reaches 1,400°C. Just imagine: this is almost the same temperature as the Earth's mantle or red-hot volcanic lava. At high temperatures, the fire passes to the upper layer of the charge.

CHARGE
— a mixture of materials that is loaded into a smelting furnace to obtain a specific metal composition.
SINTERING
— the conversion of fine powdered or dust-like materials into larger, porous products using high temperature or pressure. Sintering products in steelmaking include sinter and coke.
The combustion zone gradually moves from the top down. The whole process takes 10-20 minutes. The baked "cake" needs to be cooled in a special place. That is what it is called — the cooling zone. The hot sinter is cooled to 400-600°C in a vacuum.

At the end of the machine, the finished product is dropped from the carts, crushed, screened, cooled with air or water and sent to the blast furnace. Small pieces of sinter, or returns, go back to the mixer to prepare the charge — they will be used to make the next batch of sinter.

There is just one ingredient left and we will have everything we need to smelt pig iron.

FIG. 6 SINTER PRODUCTION
C H A R T E R 5
In cooking, spices are used to turn an ordinary dish into a culinary masterpiece. The steelmaker's kitchen has its own magical seasoning — fluxing limestone.

Every person has seen limestone at least once in their lives. Have you written with chalk at school? Do you know what happens if carbide
is mixed with water? Chalk, lime and carbide are all made using limestone. For example, lime is baked limestone.

Limestone is a soft rock formed at the bottom of the sea from the remains of creatures that lived in the water. In Ukraine, limestone
deposits are found in the eastern, southern and western parts of the country. In addition to steelmaking, the material is used in the food, chemical, glassmaking, construction and agricultural industries.

Flux is a type of "helpful bacteria" that is added during the smelting of pig iron and steel. Limestone binds waste rock, ash and other undesirable impurities and is removed from the furnace in the form of liquid slag. It is the flux that makes it possible to successfully smelt
and produce metal of sufficient quality.

Limestone, lime, bauxite, fluorspar and chamotte rubble are most often used as flux. The main types of flux in steelmaking are limestone
and lime, which is made by baking limestone. Huge amounts of this material are used in smelting pig iron and steel. Each tonne of pig iron requires up to 10 kilogrammes and each tonne of converter steel requires up to 80 kilogrammes.
CONVERTER
(from the Latin word converto — change, transform) — a type of furnace used to smelt steel from molten pig iron and scrap that is blown using air or technically pure oxygen. This is the world's most common method of steel production.
FLUX
(from the Latin word fluxus — flow, current) — the inorganic substances that are added to ore when smelting metals from it to lower its melting point and help to separate the metal from the waste rock. In steelmaking, limestone is most often used as a flux.
Egypt's pyramids were mostly built out of limestone that was often quarried right next to them
Limestone is mined in open pits. The top layers of earth are stripped back, then the limestone is lifted from the quarry with excavators and
sent for processing. The stripping process is the same as for mining ore. A bulldozer or loader is used to remove the fertile topsoil, or black earth. It is stored to be used later to re-cultivate the land that has been disturbed by mining operations.

Next comes a clay layer with a thickness of around 20 metres, which is removed by excavators. Then the low-quality limestone directly below the clay layer is removed.

The excavator bucket cannot always cope with the strength of the rock. In such cases, drilling and blasting operations often precede mining. This is a very important part of the overall process. A solid layer of limestone is drilled, then explosives are placed in the holes and detonated.
A BelAZ truck is able to carry 4,600 tonnes
of rock in a single shift, which is equal to the mass of 2,500 passenger cars
The average depth of one hole is 15 metres, although they can reach up to 32 metres. The diameter is 25 centimetres. Several holes are
often drilled at once. It takes around an hour to drill each hole. The explosions take place in succession with a delay of several hundredths
of a second.

The limestone is loaded into vehicles and transported to crushing and processing plants. The limestone passes through jaw and cone
crushers that operate on the principles of crushing, abrasion and fracturing. The pieces are then sent over vibrating screens for classification.
The finished product is loaded into railcars and small off-spec pieces, or screenings, go back to the quarry. There, they are piled on the
territory that has already been developed, which is then re-cultivated. The topsoil layer that was removed is replaced. Trees are planted. This helps to reduce the impact on the environment.
C H A R T E R 6
At last, the time has come for a true spectacle. When pig iron pours out of a blast furnace, it resembles a volcanic eruption or fireworks display. One cannot help feeling amazed by it.

We now have all the ingredients we need to cook the main dish in our steelmaker's kitchen. We have mined coal and processed it into coke, taken ore from the depths of the Earth and turned it into sinter. We have learned what flux is and what limestone is used for. Now, we will put all these ingredients in a massive pot, called a blast furnace, and begin to cook pig iron.

Pig iron and steel are alloys of iron and carbon with other chemical impurities. The thing they have in common is iron. The difference
between them is that there is more carbon in iron than in steel. Pig iron is used to make a lot of things, from sewer manhole covers to
radiators and pans. It can be further processed into steel by adding scrap steel and alloying elements to reduce the concentration of
carbon and harmful impurities like phosphorus and sulphur, which make steel brittle and fragile.

In an ordinary kitchen, the cook wears an apron and pulls back any long hair. We do the same thing: steelmakers must wear protective
suits, helmets and goggles.
ALLOYING
(from the Latin word alligare — bind) — the process of purposefully changing a metal's composition using alloying elements (for example, tungsten, chromium, vanadium, manganese, molybdenum and titanium) to adjust its structure and other physical, chemical and mechanical properties.
HOW A BLAST FURNACE WORKS
THROAT
— the top part of a blast furnace shaped like a cylinder.
MIX
— the steelmaker's term for assortment: a set of steel products of different shapes and sizes.
GRIZZLY
— a device containing a screen that is used to sort ore, coal and other bulk materials into pieces of various sizes. It got its name because of the noise it makes.
BOSH
— the middle of a blast furnace, its widest part, which has a cylindrical shape.
HEARTH
— the lowest part of a blast furnace where pig iron and slag collect.
HEARTH BOTTOM
— the bottom of a blast furnace.
Just like the most important part of a kitchen is the oven, the most important part of a steel plant is the blast furnace. Compared with kitchen appliances, it resembles a crockpot. It is two things in one: a stove and a pot.

A blast furnace is shaped like a large, round tower. It is 35 metres tall and has a working volume of 1,000-5,500 cubic metres. The most important thing to remember about a blast furnace is that once it is fired up, it must keep working constantly, because the pig iron smelting process cannot be stopped.

Inside a blast furnace, the temperature reaches 2,000° C. It has an inner lining of refractory (fireproof) material and an outer casing of steel. The top of the blast furnace is called the throat. It is about 8 metres wide. This is where they load the charge, a mix of components containing iron (sinter and pellets), coke and flux. The size, quality and quantity of each individual ingredient affects the final
product. If the pieces are larger than necessary, they are passed through screens called grizzlies. Then they are sent to the blast furnace in batches.

Either skip hoists or conveyors are used to lift the ingredients to a height of 35 metres. The ingredients are continuously fed into the furnace in layers. A charging machine is used to ensure the blast furnace remains sealed and the charge is distributed uniformly. It takes about six hours from the time the ingredients are loaded until the dish is ready to serve.

The blast furnace's widest part is called the bosh. It is shaped like a cylinder and located in the middle of the furnace. The ingredients come down the throat into the stack, which is located between the throat and bosh. The lowest part of the blast furnace is called the hearth. This is the heart of the furnace. It is here that pig iron and slag are collected. The bottom of the blast furnace is called the hearth bottom. It sits on a reinforced concrete foundation.

SMELTING PIG IRON
TUYERE
— a nozzle through which gas is blown into a metallurgical furnace or ladle.
COWPER
— a blast furnace's air heater. This is a vertical, cylindrical steel casing with an internal refractory nozzle. It is about the same size as a blast furnace. Each furnace usually has three or four cowpers.
It takes very high temperatures to cook in a blast furnace. Coke is the primary fuel. It is ignited using heated air. Like a bonfire in the forest, you must blow on the logs to get them to catch fire. The process is called a hot blast.

The air is enriched with oxygen to get the flame burning faster: this is called a fuel-enriched blast. The upper part of the hearth has special devices used to blast in the air, and these are called tuyeres. They are made of double-walled pipe. Water circulates between the pipe walls to cool the tuyeres. The tuyeres blast in air that has been heated to 1,050-1,300° C. The heating process takes place in the blast furnace's air heater, which is called a cowper.

The cowper is only slightly smaller than the blast furnace itself. It has a vertical cylindrical steel casing and an internal chessboard-like nozzle made of refractory bricks. Purified blast-furnace gas is fed into the cowper and burned in the combustion chamber. The combustion gases rise to heat the brick nozzle. When the required temperature is reached, the heating is stopped, and the cowper is switched to blast mode to heat the tuyeres.

Each blast furnace usually has three or four cowpers. While two heat up, the others are in hot blast mode. Their airflow is switched to maintain a continuous temperature. The hot air from the tuyeres ignites the coke near them. The tombustion gases rise to heat the charge. The temperature softens it and it descends into the hearth. As a result of a chemical reaction, the iron is reduced and enriched with carbon. It melts and drips into the hearth, forming pig iron.

Modern blast furnaces emit 1,250-1,800 cubic metres of gas per tonne of pig iron. This gas is used to fuel other processes in the steelmaker's kitchen. Just like wheat is washed and separated from the chaff before it can be cooked, last-furnace gas needs to be purified by removing dust.

2,250 оС — is the maximum temperature
of a blast furnace. This is nearly half
the temperature of the Sun's surface
The amount of dust in the gas depends on how the raw materials were prepared for smelting, how strong the coke was and how the furnace operated. Under poor conditions, the amount of dust can reach 100 grams per cubic metre. Under good conditions, it is 30-35 grams per cubic metre. For the burners to operate correctly, blast-furnace gas is purified so that its dust content does not exceed 5 milligrams per cubic metre.

Each blast furnace has its own gas purification system, which is made of several devices installed sequentially. Dust is classified into coarse, semi-fine and fine. Blast-furnace gas can be purified using dry and wet processes. First, a basic dry purification is performed.
Then comes semi-fine purification. The gas is thoroughly moistened, and the wet dust particles are removed as a sludge. The final stage is fine purification, which is performed by electrifying the dust particles.
TYPES OF PIG IRON
MOULD
— 1) a special form that is filled with liquid metal to produce slabs; 2) a steel box used for loading raw materials into steel-smelting furnaces.
We are done, we have made pig iron! However, there are different kinds of pig iron. Depending on what it will be used for, pig iron is divided into categories: conversion pig iron (which is further smelted into steel), foundry pig iron (used for casting products) and blast-furnace ferroalloys (used in steelmaking).

Commercial pig iron, which is intended for sale, is fed on the casting machine's conveyer belt from two parallel continuous chains. They are attached to pig iron casting forms called moulds. These are special forms that molten pig iron is poured into from the ladle. The future ingots (called pigs) are sprayed with water to cool. The chains move continuously. The pigs cool, are overturned and fall along a trough onto a railway platform or into a trolley. Each pig weighs 12-18 kg.

The blast-furnace slag is not wasted, either! It is used to make reinforced concrete structures and roads. Liquid conversion pig iron is further smelted. It is used to make steel, which you will learn about in the next chapter.
2,500,000,000 frying pans could be made
from the amount of pig iron produced
by Metinvest within a year
FIG. 7 PIG IRON PRODUCTION
C H A R T E R 7
The signature dish in the steelmaker's kitchen is steel. There are tons of different types of steel: it is classified by its use, chemical composition, quality and structure. However, there are not nearly so many production methods. The main ones are the converter, open-hearth and electric-arc methods. The names come from the machines that make the steel: converters, open-hearth furnaces and electric-arc furnaces. The converter method is most popular. It is used to smelt two-thirds of the world's steel.
CONVERTER PRODUCTION
To make converter steel, we need conversion pig iron and scrap steel or pig iron. We use flux as a seasoning: lime, limestone, fluorspar or bauxite. And for a bit of spicy zest, we use oxygen as an oxidising agent.

Pig iron contains excess carbon, silicon, manganese, as well as harmful impurities such as sulphur and phosphorus, which make steel brittle. Such material cannot be forged or rolled. We need to reduce the quantity of harmful impurities, which we do by oxidising the metal with oxygen.

Steel is made in a special saucepan called a converter. Its name comes from the Latin word converto — change, transform. It is a pear-shaped steel vessel lined on the inside with refractory bricks. It has a capacity of 50-400 tonnes.

A converter is quite an agile vessel. It can rotate 360 degrees around its horizontal axis. To load the ingredients, the converter is tilted and filled with scrap metal through its neck, and hot (1,250-1,400° C) pig iron is poured in. The converter is then returned to its vertical position and a water-cooled tuyere is placed inside to supply oxygen.

The oxygen stream mixes and oxidises the liquid metal. The chemical reaction generates heat, warming the converter's contents to the desired temperature. No fuel is used for heating. The silicon and manganese impurities combine with the oxygen and burn. As the temperature rises, the excess carbon is also burned. The iron becomes intensely oxidised. Iron oxide dissolves in the slag and metal, enriching the metal with oxygen.

Smelting takes anywhere from half an hour to an hour. Once the carbon content reaches the desired level, the conversion is finished. The converter is tilted again, and the molten steel is poured through a tap hole into a ladle. It is then tilted to the other side and the slag is poured through the neck into a special pot installed in a slag carrier under the converter.

The alloy now needs to be conditioned by balancing its temperature and chemical composition, removing harmful impurities and adding alloying elements.

This is called steel ladle treatment. It is done in a steel-teeming ladle with the help of additional equipment.

Oxygen converters are primarily used to smelt carbon steel (with a carbon content of 0.02-2.00%), low-alloyed steel and alloyed steel (by adding chromium, nickel or molybdenum).

The last stage involves casting the steel into billets, which are then processed into metal products (plates, sheets, coils, rails, rebars, rods and other products). Steel can be cast using several methods. For example, molten steel can be poured from a ladle into a casting form, which is a type of pig iron form used to make a slab. The steel hardens in the casting form and the slab is then rolled on a blooming mill. This is how the billets used for metal products are made. The shape of the casting form determines the type of end product: square billets are used to make long products, rectangular billets are used to make steel sheets, and round billets are used to make pipes. This steelmaking method works particularly well for high-alloyed steels.

Converter from the inside
BLOOM
— a steel billet with a square or rectangular cross-section. This semi-finished steel product is used to make long products.
Steel can also be cast continuously, using a special piece of equipment called a continuous-casting machine (CCM). It immediately gives the billets their desired shape. During continuous casting, steel is poured from the ladle into a type of trough called a tundish. Below that is a water-cooled crystalliser. It is like a casting form, only without a bottom. Before the metal is poured, a starting bar — a steel rod with a replaceable head — is placed into the crystalliser. The starting bar acts like the bottom of a casting form and is removed from the billet after casting. The billet comes out with its insides still molten and a cooled outer skin.

To fully solidify the billet, it is cooled with water. The semi-finished product is then cut into pieces. This is how slabs, blooms and billets are made.

FIG. 8 CONVERTER STEEL PRODUCTION
OPEN-HEARTH PRODUCTION
This technology dates back to the middle of the XIX century. Openhearth production uses the Siemens-Martin process, the name of which is derived from the surnames of Carl Wilhelm Siemens, the German engineer who first developed the open hearth furnace, and Pierre-Émile Martin, the French engineer and metallurgist who applied the technology in 1864. Until the 1970s, this was the primary process used to produce steel. Open-hearth furnaces have since been replaced by oxygen converters and electric-arc furnaces.

We use the same ingredients for this recipe — pig iron, scrap steel, iron ore, flux and alloying additives. The main difference from converter production is that it is impossible to smelt steel in an openhearth furnace without fuel, in this case, natural gas.

An open-hearth furnace is like a giant bathtub that is lined on the inside with refractory bricks. There is a vaulted ceiling above the bathtub and a lower shell below it. The front of the furnace has special charging doors used to load the ingredients. The back has holes used to pour out the metal and slag. To keep the steel from flowing out too soon, the holes are plugged with refractory clay.

Open-hearth furnaces come in various sizes. They can smelt from several tonnes to several hundred tonnes of steel. The smelting time depends on the molten metal's mass and the proportion of scrap metal in the charge. The process takes an average of 6-8 hours.

The smelting process occurs in several stages. First, scrap, ore and lime are loaded into special boxes called moulds. A charging machine loads the charge through the thick steel charging doors, after which they are closed.
FIG. 9 OPEN-HEARTH STEEL PRODUCTION
SCRAP
— junk metal and production waste metal that is re-smelted and used to produce steel.
The scrap is heated with a scorching hot mixture of natural gas and air to a temperature of 1,300-1,400° C. Molten pig iron is then poured from a ladle through a trough and into the furnace. The smelting stage involves melting the scrap, breaking down the limestone and dissolving the iron in the slag, then oxidising the impurities in the charge. The heating process causes the molten metal to rapidly emit gases, and it begins to spray. As soon as the metal "calms down", the smelting process ends.

The next stage is finishing and deoxidising the metal. The quality of the finished steel depends on whether these processes are performed correctly. The alloy is conditioned by heating the metal to remove gases and non-metallic inclusions, as well as to oxidise the carbon. This also reduces the sulphur and phosphorus content.

After that, the metal is deoxidised and alloyed if needed. At this time, the person operating the furnace, called the steel founder, takes several quick samples through inspection doors. To do so, he uses a large steel spoon-like tool to scoop up molten metal and check it for harmful impurities so that he can correct its chemical composition if needed, not unlike a chef tasting soup as it cooks.

Now the product is ready. The molten steel is poured from the furnace's steel tap into a ladle. From there, it is poured into smaller containers called casting forms. After the steel has hardened, the casting form is removed from the slab — a blank that is further processed into metal products.
ELECTRIC-ARC PRODUCTION
Since the second half of the XX century, an ever-increasing amount of steel has been produced using electric-arc furnaces. This production method requires a lot of electricity. That is why it has only been developed in the countries that can afford it, including the US, India and China. Today, electric steel accounts for about a third of overall global production. Most of this steel is smelted in electric-arc furnaces.

An electric-arc furnace consists of an iron upper shell with a spherical bottom. The inside of the upper shell is lined with refractory bricks. The furnace proper, where the smelting occurs, has a rotating cover. The device resembles a huge crockpot.

To cook a dish, the "pot" is filled with the charge, scrap metal and the remaining ingredients needed to make a particular grade of steel. It is seasoned with limestone. After the ingredients have been loaded into the pot, the lid is closed, the electrodes are lowered and the electrical current is switched on. The pot's contents are heated to 1,500° C and become even hotter once the electrodes get to work. However, the energy comes not from the electrodes themselves, but rather from the arc that occurs between them and the metal charge that has been loaded into the furnace. Steelmakers got the idea by observing a natural phenomenon: lightning. An electric charge is carried from the electrodes to the liquid metal just like lightning surges to the ground from the clouds.

Once the smelting is complete, steel and slag remain in the furnace. The slag absorbs any unnecessary impurities and floats to the top. The purpose of the process is to obtain a semi-finished product with the necessary chemical composition.

Steel founders have a secret that lets them check the steel's quality while it is still inside the vessel. They take samples of the slag. Performing a chemical analysis of the slag helps to determine whether the steel is ready for use.

To control the smelting process, the furnace has an observation hole, a steel tap hole and a slag tap hole.

Electric-arc furnaces come in various capacities ranging from 0.5 tonnes to 400 tonnes. The smelting time is only 40-55 minutes, which makes it possible to do up to 40 smeltings a day. Electric-arc furnaces can produce high-quality steel. This method is used for smelting high-alloyed, structural and specialty steels, as well as alloys.

Electric-arc furnace
А 7,000 km line will be formed if you put together
all the slabs which were smelted by continuous casting machine #1 at Ilyich Steel within 25 years — this equals to the length of the Amazon River
FIG. 10 ELECTRIC-ARC STEEL PRODUCTION
C H A R T E R 8
Every sector of the economy needs steel products: 50% is used in construction, 16% for mechanical equipment, 13% for automobiles, 5% for other transportation and 3% for electrical equipment.

Every day, the world produces enough steel to build 548 Eiffel Towers. On average, 215 kg of steel products are produced annually per inhabitant of the Earth. Ukraine also has something to be proud of. We are one of the world's largest steel producers. Year after year, steelmakers invent new steel grades to produce even more types of products. The combination of different shapes and sizes of products is called the product mix.

Products are divided into flat, long, pipe and roll-formed steel. Various types of products are included in these groups. For example, long products can be large, medium and small, depending on their size. All products are made from semi-finished products, which only differ from one another by their shape. Slabs are made into hotrolled coils and sheets, square billets are made into medium and small rolled products, blooms are made into large rolled products and round products are turned into pipes.

Slab
FLAT PRODUCTS
Have you ever seen how homemade noodles are made? If you have, then it will be easier for you to understand how metal is rolled. After we make steel slabs, we need to turn them into a finished product.

The most common way to shape metal is rolling. It is done using a special mill. Like a kitchen rolling pin and dough, the metal is passed through a set of rollers. The kitchen is fine, but everything is much more interesting in steelmaking! Here, we are not limited to one type of "rolling pin". Rolling mills can process steel billets, sheets and strips. When a steel slab passes through the rollers, it becomes thinner and longer. Rolling can be either longitudinal or transverse.

Most rolled products are rolled longitudinally. That is how sheets, coils and long products are made. Flat steel can be thick (more than 4 millimetres) or thin (less than 4 millimetres). To make pies, the dough is rolled out warm, but for shortbread it must be cold. This is also how our hot-rolling and cold-rolling mills work.

To make thick steel sheets, slabs enter the mill after the continuous-casting machine. The slab is then heated in a furnace and rolled several times in both directions until it reaches a predetermined thickness. The resulting metal is cut into sheets of the required length and then undergoes finishing: heat treatment, descaling, etc. The sheet is now ready for use. It is needed by shipbuilders, machine builders, large-diameter pipe makers and other consumers.

Packed coils in warehouse
1,000,000 LEGO bricks are roughly equivalent to the volume of one slab, which is a semi-finished product used to make steel plates, sheets and rolls. Their average weight is 20-30 tonnes
SLAB
— a steel billet with a rectangular cross-section. A semi-finished steel product used to produce sheet steel.
In addition to sheets, slabs are also used to make coils. It starts the same way. The slab is heated to a temperature of 1,200° C, passed through an initial rolling, then is sprayed with water for descaling and rolled again. The metal is cooled with water or air and wound into a coil by a coiling machine. This type of steel can be used in construction, machine building and pipe making, or it can be sent for further cold rolling. Why suddenly cold? After a certain thickness is reached, hot rolling is no longer effective. The metal quickly cools, its resistance to deformation increases and, due to the frequent heating, even more scale forms on the surface. So, sheets thinner than 1.5 millimetres are made by cold rolling. This makes it possible to more precisely calculate the thickness of the final product. It also improves the product's surface quality and mechanical properties.

Before being cold rolled, hot-rolled metal undergoes pickling treatment. The surface of the rolled product is treated with a solution of sulphuric or hydrochloric acid. Part of the scale dissolves and part flakes off. The metal is then washed in pure water and the acid residues are neutralised in an alkaline bath. The metal is lubricated with special oils or emulsions and rolled. Once it reaches the required thickness, the rolled product is finished by either heat treatment or galvanisation. The steel is annealed to remove stiffening.
Imagine removing the crust from bread to make the entire inside of the loaf the same hardness. Annealing is a type of heat treatment in which the metal is heated to a certain temperature and held there for some time, and then gradually cooled. Annealing lets the metal "rest", reduces its hardness and makes its microstructure homogenous. After that, the sheet is sent for final finishing or tempering, which is cold rolling at a low pressure without lubrication. Tempering improves the steel's surface quality. Sometimes, products are sent to customers without annealing in a cold-worked state.

Less than 0,1% of the mass of products that Metinvest's plants produce in a day is needed to launch into orbit one of the world's most powerful launch vehicles,
Elon Musk's Falcon Heavy rocket
The final stage is finishing. The edges of the sheets or coils are cut off, the metal is cut to length and a protective coating is applied. To make the product resistant to mechanical damage and corrosion, it is coated with zinc, tin or aluminium. The most economical method is hot galvanisation. This is when the product passes through a bath of molten zinc. Galvanised products can remain rust-free for up to 30 years. Cold-rolled coils are used in construction, as well as to make car parts and household appliances.

Flat products — including sheets, coils, strips and plates — are end products used only by steelmakers. Other manufacturers do not use these products in their initial form. They must be processed further. Today it is a steel coil, tomorrow it is the roof of a house, body of a car or shell of a refrigerator.

For consumers who need products in a certain shape, steelmakers have a separate menu — long products. To figure out what they are, remember your favourite childhood dish — pasta. The more intricate the shape, the more interesting the pasta: bowties, elbows, butterflies. From here, we will talk about the geometry of the dough and large shapes.
FIG. 11 PRODUCTION: FLAT PRODUCTS
LONG PRODUCTS
Long products are one of the main types of rolled steel. This includes different shapes that are not hollow inside, but solid. They come in large, medium and small sizes. The shapes are divided into simple (circles, squares and strips), shaped (rails, channels, angles and beams) and specialty steel products (wheels and balls). Each of these varieties is rolled from blooms or square billets. Remember the semi-finished products from the steel production chapter? To imagine what blooms are, let's set the dough aside. Today, we have chocolate bars. Blooms are steel billets with square or rectangular cross-sections and sides of 140-500 millimetres. They resemble a parallelepiped. The mass of one bloom can reach 25 tonnes.

Blooms are made from slabs by rolling in a special mill or from liquid metal poured in a continuous-casting machine. A blooming mill usually has two rollers, sometimes three. Metal slabs are delivered on railway platforms to the blooming workshop's heating wells. There, the steel is heated to 1,100-1,300° C and brought on slab carriers to the blooming mill's rolling conveyor. The slabs are rolled several times until they reach the necessary sizes and then the front and rear ends of the roll are cut. Now, the semi-finished product is ready to
become beams, channels, rails and other forms. It depends on which mill they go to next.

What do rails remind you of? Noodles? Maybe spaghetti? Ukraine's only producer of main-line rails is Azovstal. Just imagine: over the years, this giant factory in Mariupol has produced enough rails that they could wrap around the Earth's equator 16 times!

Metal cutting
Earth-Moon Railway
The combined length of all the rails produced at Azovstal would be enough to build a railway to the Moon
Speed shortens distance. Rails are a vital part of the history of highspeed trains. Semi-finished products arrive at the site of the mill's heating furnaces to be brought to the required temperature before rolling. The heated billet is then sequentially pressed between various calibres cut in two rollers that rotate in opposite directions. In the process of rolling rails, the blooms become nearly 10 times longer. Each bloom makes two 25-metre rails. Trains travel around Ukraine on such rails. After rolling, rails and sections are cut into measured lengths, branded, cooled in refrigerators and sent for final processing and acceptance.

For example, after rails are rolled and cooled, they go through a mangle and are checked by ultrasound. After being tempered and straightened, holes are drilled in the ends of each rail so that they сan be connected end-to-end. The rails are then transferred to inspection racks to be inspected and sorted, and from there to the warehouse.

Blooms are a fairly universal semi-finished product. In addition to rails and specialty sections, blooms can be used to produce large beams, channels, angles and other long products. Consider them giant bows or horns of dough. The production technology at a large long product mill is similar to that at a rail and beam mill. Blooms are heated in furnaces and rolled in several stages. The billet is sequentially pressed between several calibres cut in rollers. After rolling in the final calibre, the shape of the finished product is obtained.
The products are transported to hot-cutting saws and cut into lengths of 4,000-24,000 millimetres. They are then cooled and straightened on special machines and, if needed, cut again. This time, using cold-cutting saws to obtain the final length specified by the customer. After that, the finished products are packaged, weighed and stored.

For dessert, we have rail fasteners and grinding balls. The same rails we talked about earlier cannot exist alone. Like a cake cannot exist without icing, rails cannot exist without fasteners.

These are straps and baseplates. Shaped baseplates are used to reliably connect the rails to the ties. Straps with boltholes connect separate rails into a long railway line, so that we can travel anywhere. So, we make strips into straps. We chop them into blanks. We heat the blanks in the furnace, punch holes in them, straighten and label them, then quickly cool them in oil and water and "set the table" for sorting.

Angles
Now we serve a fruit course. We can use tangerines, oranges and grapefruits. As you may have guessed, we are talking about grinding balls. They have various diameters, from 40 millimetres to 120 millimetres. They are used to grind ores of non-ferrous and ferrous metals at mining and processing plants, as well as in the cement and coal industries. Basically, if you need to grind something that is solid, ball grinders are a perfect fit.

The machine that rolls grinding balls is called a ball mill. Round blanks are heated in furnaces and passed through two rollers with circular grooves. The rollers are angled toward the axis of rotation and spin in one direction, so that balls can be formed from a solid blank between the grooves. At this point, they resemble a Christmas garland. Then they are cooled in water, tempered and
dumped into a bunker to fully cool the finished product.

Our tour of the steelmaker's kitchen is over. Together, we have visited the entire production chain, from mine to rolling mill. We have learned how a piece of ore is turned into an eternal product, steel, and what they make from it.

Production is an exciting process. It is a special treat to watch how individual elements are turned into something completely new. We invite you to take a real tour of Metinvest's steelmaking plants. There you will see with your own eyes pouring iron, hot slabs and red-hot steel… And not a single exciting moment will escape your attention.

Balls
FIG. 12 PRODUCTION: LONG PRODUCTS
C H A R T E R 9
Like a student who has just received their school diploma, steel's adult life is just beginning when it leaves the walls of the steelworks.

Once the steel turns into product, two paths open in front of it: either start immediate functioning, that is become part of a building, structure, mechanism or device; or get upgraded and only then find a worthy place.
PARTS MADE OF STEEL
Steel plants produce heaps of various steel products: thick and
thin sheets, bars, circles, squares, rails, pipes, I-beams, channels,
corners… too many to count.

Modern architects and engineers are not limited to the standard
set of factory metal products, they can create structures of any
complexity. Other plants called metalworks produce metal structures
to help them to make or assemble the parts they need.

A metalworks plant resembles a pastry shop filled with professional
equipment. There is a separate attachment for each shape. But instead
of dough, they make a steel sheet. First, the blanks are made:
long metal profiles are cut with guillotine shears and sheets are cut
with a thin laser beam or plasma stream. Small pieces are divided
into parts using high-strength saws. All the necessary holes and bevels
are cut, the edges are trimmed and ground, and the surfaces are
treated. Powerful presses are used to make the necessary shapes,
bends and protrusions in the blanks. When all the parts are ready,
the structure can be assembled. This is done using special conductors,
which are devices that help to put the parts together.

Global technological progress has also affected these plants. New
technology makes it possible to print structures, like a 3D printer.
Finished structures are delivered to the construction site. They
are usually broken down into pieces and assembled directly on
site. However, sometimes they are too large to be broken down.
Then, the transportation becomes a real spectacle. They use multiwheeled
platforms, get police escorts and temporarily remove
everything in the way.

The Darnitsa railway and automobile bridge in Kyiv — 5,500 tonnes of Azovstal steel were used in its сonstruction.
MADE WITH STEEL
Skyscrapers that people live in, family cars, bridges on the way home, wind turbines and electrical poles in fields, ships on the horizon of the sea. Steel is everywhere. Many sectors of industry could not exist without it: construction, shipbuilding, transport, metals and mining, energy and machine building. Below are just a few examples of the impressive structures that have been created using Metinvest steel.
More than 16,000 km
is the length of the longest sea route from Ukrainian ports to Metinvest's customers in Asia
Yuzhny Port, Odesa region
Olympic Stadium
The Olympic Stadium in Kyiv was reconstructed ahead of the Euro 2012 football championships. The 95-yearold stadium has been reconstructed four times. It has the capacity to seat more than 70,000 people and a total area of 145,000 square metres. It is the largest stadium in Ukraine and one of the largest in Europe. It is home to major football matches and concerts of international stars.
Carnival Vista cruise ship
The modern Carnival Vista cruise ship was launched in 2016. The ship has 15 decks, is 322 metres long and can hold nearly 4,000 passengers. It cruises along the coast of Europe and the Caribbean Sea. On board, guests can play football, basketball, volleyball, mini golf and bowling, as well as visit a ropes course and an IMAX movie theatre.
The Shard
The Shard is London's tallest building and the fifth-tallest skyscraper in Europe. It was built in 2009-12. A pyramid covered in glass panels, it reaches 310 metres into the sky. The ragged lines of the tower's spire resemble a shard of glass. That is why they named it the Shard. The 87 floors of the "vertical city" contain 127,400 square metres of offices, apartments, restaurants and a five-star hotel. The three upper viewing platforms offering 360-degree panoramas are popular among tourists. Before, you could only look at the city from such a height on board a helicopter.
Solar power plant in Lviv region
Not far from the village of Ternovytsa in Lviv region, a solar power plant with a capacity of 72 MW is being built on the site of a former chemical plant. This is enough electricity to power nearly 8,000 apartments with electric ranges or more than 500 modern trolleybuses. The first phase of the power plant is already in operation — more than 20,000 silicon photovoltaic solar panels cover an area of 12 hectares.
European Extremely Large Telescope
The European Extremely Large Telescope is called "the world's biggest eye on the sky". Construction of the world's largest telescope for studying planets outside our solar system, black holes and the Universe's dark sector is slated to be completed by 2024 in the Atacama Desert of the Chilean highland. Its job will be to find out whether there is life on other Earth-like planets. The observatory's main tool is an adaptive optical system made up of five mirrors. The largest mirror has a diameter of 39 metres and will be made of 800 separate hexagonal mirrors with diameters of 1.4 metres. This mirror will be able to collect 13 times more light than other telescopes, making it possible to obtain more detailed images. The telescope's revolving cupola will be as big as a football field (86 metres in diameter). Its total weight will be 5,000 tonnes, of which 3,000 tonnes will be the movable part. Its construction is being funded by the European Southern Observatory, an international research agency with 16 member-nations.
Apple's new headquarters
Apple Park in Cupertino, California (US) was built on a 71-hectare site in the middle of Silicon Valley. The main building is ring shaped with four levels above ground and another three underground. Underground, there are roads and parking garages. Inside the ring there is a fruit orchard with a pond. The campus has its own fitness centre, restaurants and a theatre named after Steve Jobs for presentations of Apple's new products. The walls of the campus are made of glass, solar panels are installed on the roof and the interior is finished with certain types of maple. More than twelve thousand people work in the headquarters. Steve Jobs' goal when helping to design the roughly US$5 billion project was to make the best office building in the world.
Hudson Yards
The Hudson Yards complex in downtown New York City is one of the most magnificent
projects of our time. A US$20 billion "city within a city" will be built on 11 hectares of land along the banks of the Hudson River. It will have 16 skyscrapers, shopping centres with restaurants and stores, a school and a park. The tallest building will be 386 metres.
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