STEEL Talk presents to you interesting stories of Science, Technology, Energy, Environment, Life — and of course STEEL!

A tower crane sure looks like a giant standing tall like a commander at a construction site. In fact, tall buildings can not be constructed if it wasn’t for the tower cranes. Before finding out more about tower cranes, let’s first look into an ancient construction method.

The pyramids in Giza, northern Egypt, are considered one of the 7 Wonders of the World! They are said to be built about 2,500 years ago by ancient Egyptians who piled up 2.3 million blocks totaling over 2.5 tons. The completed pyramid was gigantic — 147m high, 230m wide, and 230m long.

No one knows exactly how the Egyptians transported the stone blocks, but many scholars presume that they created slopes on the sides of the pyramid and moved the stones using a wooden roll.

They say that it took about 20 years to build a single pyramid, so when calculated, it could be said that more than 13 blocks — which weigh more than 2.5 tons — were stacked per hour, day and night. No wonder some say that the pyramids were built by aliens.

l A Tower Crane Is A Game Changer?

What if there were tower cranes of today when building the pyramids of Giza? Since a tower crane can lift construction materials amounting to dozens of tons at a speed of more than 50 to 80m per minute, it would have taken less than two to three years to complete a pyramid.

The invention of the crane goes back to 6c B.C, Greece. When the ancient Greeks built structures like the Parthenon, they needed to lift heavy marbles, and they did so by attaching sheaves to long wooden posts. In Korea, the first crane to be recorded was “Geojunggi,” and it was invented by Yak-Yong Jeong in 1794. Geojunggi was applied in the construction of Suwon Castle.

With technology development in structural mechanics, modern buildings are becoming taller and bigger. Therefore, lifting heavy materials higher has become necessary, and the construction machinery suitable for this is the tower crane.

As the name suggests, a steel-made tower crane refers to a crane that is as tall as a tower. With this machinery, it becomes possible to transport heavy loads of more than 3 tons in any direction — up and down, left and right. Thus, enabling the beautiful skylines and landmarks of downtown areas.

HSA650^*, POSCO’s premium high-strength steel for construction, was applied to the Lotte World Tower, Dongdaegu Bus Transfer Center, and Incheon International Airport Terminal 2. These places have another thing in common — they utilized tower cranes in lifting the pillars and columns crafted with HSA650.
^*HSA650(High Strength Steel for Architecture) : Steel for structural construction with high yield strength of 650Mpa-class and seismic performance.

l What Are the Scientific Principles Behind Tower Cranes?

Tower cranes are divided into T-Tower Cranes and Luffing Cranes. A T-Tower Crane is shaped like the letter “T” and consists of a tower mast, which is the vertical column, and a jib, which is the horizontal arm, forming a right angle. A Luffing Crane lifts the jib vertically and takes the shape of the letter “L” to avoid obstacles within the operating radius.

The principle of how the tower crane works is a combination of the sheaves in the Geojunggi and Archimedes’ principle of the lever. With four movable sheaves equipped on the trolley pulley and a hook to transport the load, the tower crane can lift eight times more than its original power source. And with the operator cab serving as a support point, a counter weight made with concrete is suspended on a counter jib, a horizontal arm at the rear, to balance the weight with the front jib.

The principle of the lever shows that heavier objects can be lifted by moving the trolley pulley to a point closer to the fulcrum. In fact, even on construction sites, heavy weights are moved as close to the fulcrum as possible.

l How Does the Tower Crane Become Taller?

You’ve probably seen tower cranes bustling at construction sites. And one day, you might have noticed that the tower crane was somehow becoming taller. How did this happen?

Right under the tower crane’s operator cab is a “Telescopic Cage” that provides working space for telescoping^* and supports the top of the crane with hydraulic cylinders and guide rails.

Making the tower crane taller works like this. First, the operator cab is raised about 3m along the guide rail using the hydraulic cylinder of the telescopic cage to create an empty space. Then, an additional mast that acts as a pillar is added and fixed with bolts. So, the height of the tower crane grows to the height of the new mast.

^*Telescoping: A method of “inserting in” a new mast on the stable base of the tower crane.

Tower cranes whose foundation is fixed with reinforced concrete can be raised up to 150m or more by installing steel bracing at regular intervals on each floor of the building.

STEEL Talk presents to you interesting stories of Science, Technology, Energy, Environment, Life — and of course STEEL!

l Buildings: Standing Firm Like ‘Giants’

Bones are like solid columns supporting the entire human body. And the buildings that we see around us function similar to the human body. They are like ‘giants’ standing tall — a much bigger version of the human body. The columns of the building support the entire structure, just as bones support the human body, and this column is steel! The steel used here is called construction steel and it is applied to various structures such as buildings and bridges around us.

Just as the bones inside our body are invisible to the naked eye, the steel material for construction, the bones of the building, is also placed inside the building and cannot be seen easily. However, It is considered as the most important material because it is closely related to safety.

The tallest building in Seoul is the Lotte World Tower! A huge amount of POSCO steel plate and high-performance construction steel were applied in its construction. If you take an x-ray of this building, you might be able to see POSCO steel supporting it entirely, just like you can see the bones inside your body in an x-ray!

l Looks Matter Too!

Supposing a building is a human body, the skin would be its exterior wall. Architects struggle a lot to make a building aesthetically pleasing. That’s why the exterior walls of buildings are decorated with shiny glass or ornamental stone. Recently, steel is often used as well because of its strongness and artistic properties.

Do you remember Pengsoo House that POSCO had built for the EBS mascot Pengsoo? The exterior walls of Pengsoo House, where Pengsoo’s face is printed, are also made of steel. The steel plate applied here is POSCO Advanced Resolution printing Technology (PosART). PosART allows high-resolution inkjet print hence emulating the textures and patterns of various materials, including marble, wood, and fabric. As long as there is an image file, anything is printable. Last year, POSCO had launched INNOVILT, a premium brand of steel products for construction. PosART is one of these INNOVILT products, and it won the worldsteel Steelie Awards ‘Innovation of the Year’ in 2019.

Steel is used not only for exterior walls but also for roofs. The roof of Incheon International airport’s Terminal 2 was made with POSCO stainless steel fabricated with reduced reflectivity to prevent glare for aircraft pilots during takeoff and landing.

l Keeping the Building Alive!

Blood vessels of the human body serve as channels to deliver oxygen to every corner. Just as we have blood vessels and nerves, buildings also have invisible “blood vessels” and “nerves” that keep them alive — “pipes”.

Most of the pipes in the building are made of steel. If the pipe is rusted, water or gas may leak inside the building, which might trigger a big accident. Also, if water travels through the rusty pipes, it will be contaminated and harm the health of people. Therefore, corrosion-resistant stainless steel is appropriate in making the pipes of buildings.

STEEL Talk presents to you interesting stories of Science, Technology, Energy, Environment, Life — and of course STEEL!

Medical dramas depict events and stories that happen at a hospital. In a scene inside the operating room, a doctor asks for a scalpel, a surgical instrument. Then, it is handed over instantly. The shining silver-looking surgical tools here seem threatening, but they’re actually the opposite once you get to know them. In fact, these steel-made tools play a crucial role in saving our lives.

“Cleanliness” and “hygiene” would be the two keywords that people are most interested in these days, due to the COVID-19 pandemic. The government, local authorities, corporates, and individuals are all doing their best to sanitize public places, such as hospitals, theaters, and public transportation facilities. The most needed and useful thing here is medical stainless steel known as “Surgical Steel.” POSCO Newsroom presents to you the secrets of the life-saving surgical steel.

l No More Germs! Stainless Steel Innovates the Medical Field

Before we learn more about surgical steel, let’s first go back to when stainless steel was invented.

It was only after the invention of stainless steel in 1913 that patients could get medical treatments in sanitary environments. In the past, many people lost their lives due to infections while undergoing medical treatment in an unsanitary environment.

The World Health Organization (WHO) has also cited that one of the most serious challenges that the modern healthcare industry faces is patient infections during treatment. Hundreds of millions of patients worldwide are exposed to diseases caused by infection every year, so maintaining a clean and healthy environment is paramount.

In fact, a publication by WHO in 2010 revealed that per 100 patients, seven in developed countries, and ten in developing countries suffer from healthcare acquired infections (HAIs). In high-income countries, about 30% of intensive care unit patients suffer from HAIs while the figure is two to three times higher in the case of low-income countries.

So what’s so special about surgical steel, or medical stainless steel? The answer is that it’s an excellent material in terms of hygiene! Surgical steel is resistant to corrosion, which means that there is no need to worry about any corrosion or degradation. Another advantage would be that it can be safely sterilized without any other side effects. Stainless steel is used in hospitals all around the world, in surgical knives, injection needles, and screws to hold broken bones, since it is safe to the human body — even inside!

What if we don’t use surgical steel? Rusty steel will penetrate your body, which can eventually cause tetanus, a terrible disease, or infection of various germs. Then how come stainless steel can be rust-free? Let’s look into the answer!

l Stainless Steel: The Secret Lies on the Passive Film!

Stainless steel is alloy steel made by adding chromium, carbon, nickel, manganese, etc. to iron (Fe). So, it is a highly corrosion-resistant material and versatile because it has excellent malleability to deform and it can withstand high external impact.

Stainless steel does not rust easily thanks to its special protective film called, ‘passive film,’ on the surface. This special protective film is chromium oxide (Cr2O3), which is formed spontaneously through the oxidation of chromium (Cr). Approximately 2nm (2mm divided by 1 million) in thickness, the film is so thin that it is invisible to bare eyes but it’s extremely solid and protects the base iron from oxidation. Even when a part of the film is destroyed due to a scratch, it quickly regenerates as the chromium meets oxygen again.

l Sterilizing Power, the Amazing Property of Stainless Steel!

In 2017, the International Stainless Steel Forum (ISSF) published a study result on its website demonstrating the amazing sterilizing power of stainless steel.

The study was jointly conducted by Manchester Metropolitan University in the UK and AgroParisTech, one of the most prestigious universities in the field of life and environmental science in France. The study explains how hygienic and crucial stainless steel is to use in environments where we are exposed to germs, like hospitals. Here is a brief explanation.

First, the researchers prepared two stainless steel samples. One was aged stainless steel (A), which was contaminated and cleaned repeatedly on purpose, and the other was newly-made stainless steel (B). Both sample (A) and (B) were exposed to ‘Staphylococcus aureus,’ a deadly bacteria responsible for food poisoning and infections, and ‘Pseudomonas aeruginosa,’ a bacteria difficult to treat. Both samples were then cleaned with the same disinfectant.

What was the difference between sample (A) and (B)? Surprisingly, the two samples showed almost no difference. Both samples were revealed to be 99.9 percent effective against Staphylococcus aureus and 97.6 percent effective against Pseudomonas aeruginosa. The experiment confirms that stainless steel can be used hygienically and safely over a long period of time.

Today, we learned about stainless steel that saves our lives. The scary-looking medical tools in the hospital might look differently to you now that you know about what surgical steel is. Stainless steel in the hospitals might look threatening, but remember! They’re actually our life-savers!

STEEL Talk presents to you interesting stories of Science, Technology, Energy, Environment, Life — and of course STEEL!

“Amusement park,” the word alone is enough to put a smile on your face. It’s a perfect place to take pictures, eat delicious food, and make pleasant memories with friends and family. The rides in the amusement parks are mostly made of steel. Especially, steel is a must in making thrill rides, such as a Drop Tower, which enables you to experience free-fall from top to bottom in the blink of an eye, and super-fast roller coasters. POSCO Newsroom presents to you the story of steel hidden in the rides of the amusement parks.

l Safety, the No.1 Priority in Thrill Rides!

Just looking at the thrill rides makes you feel all excited! Amusement rides must be safe and strong since people ride on them, but at the same time, they should be made with a material that can work properly according to circumstances and last for a long time. The material that satisfies all of these conditions is none other than “steel.” Let’s dive into the details!

l Roller Coaster: Enjoy the Safety & Fun on the Steel Tube Rail!

Did you know that the origin of the roller coaster is a wooden coal truck? There is a hidden story of how the roller coaster became the steel cart of today from the former wooden carts.

The roller coaster, which is one of the must-visit spots in an amusement park, originates from trains that used to carry coal mines in the Bavarian region of Germany. It was found that when people rode on the wooden minecart — a cart with no top cover used to transport coals — from a high place to a low one, they could relieve their stress. In 1851, the concept of this roller coaster was introduced at the “World’s Fair” held in London, England.

However, the wooden roller coaster introduced at the “World’s Fair” had disadvantages of being deformed and corroded by exposure to ultraviolet rays. Due to this reason, modern roller coasters were born made of steel.

Later on, as the steel industry developed, La Marcus Thompson installed the first modern roller coaster, “Gravity Pleasure Switchback Railway,” in New York, 1884. This first roller coaster in the U.S. was set up in New York’s theme park in Coney Island, and it became so popular that, in the 1920s, about 2,000 roller coasters were installed throughout the U.S.

However, with the Great Depression in 1929, two World Wars, and the emergence of new entertainment industries, such as TV and movies, the popularity of roller coasters began to fade. In the U.S., the number of roller coasters, which was formerly near 2,000, reduced to 172 in 1970. But they soon boomed again, as the modern steel technology made it possible to construct roller coasters with steel tube rails, which led to a huge structure providing faster speed with enhanced stability.

In the third story of STEEL Talk, we learned about why the amount of carbon (C) in steel is important. As carbon contents in steel increase, its hardness — resistance to pressure — increases as well, but it becomes fragile and doesn’t easily stretch. Conversely, the less carbon contents in steel, the more flexible and stretchable it becomes. So, it is necessary to adjust the hardness of the steel product with the amount of carbon depending on its use nor to add other elements accordingly. Thanks to this versatile properties, the types of steel have become more diverse, and its performance is also improving day by day.

Steel is playing a crucial part in designing roller coasters that require appropriate engineering skills. Various high-performance steels, such as construction steel and specialized steel, are used in roller coasters. Watch the worldsteel video above to grasp the details.

Except for certain types of roller coasters where wood is used, there is no substitute for steel in making roller coasters.

l Magnets Behind Drop Tower Seats?

The Lotte World Gyro Drop is probably the most familiar Drop Tower ride in Korea. It is a thrill ride that has been popular in Korea since its first appearance in 1998. There is an interesting scientific principle behind this Gyro Drop ride with regard to the “magnetic properties” of steel.

If you’ve ever been on the Gyro Drop, you might have experienced the tension and anxiety of not knowing when you will drop once you get to the top of the Gyro Drop. However, in a few seconds, you are soon filled with the thrill of dropping suddenly and the relief of reaching the ground! Many people love this ride because of this excitement. The reason why the Gyro Drop can drop down and land at the bottom safely is because of steel’s “magnetic properties.”

If you put metal between the N pole and the S pole of the magnet, an electric current flows instantaneously, and the metal becomes magnetic. As a magnetic field is generated around this metal, the magnetic field of the metal and the magnetic field of the magnet repel each other. The Gyro Drop uses this repulsive force as a brake.

The safety of the people on the ride is paramount, so the brakes on the Gyro Drop must work at all times, even when the amusement park suddenly goes out of power. Especially since the Gyro Drop falls at high speed, brakes that utilize frictional force aren’t appropriate because they might wear out when used for a long time. Then what kind of a brake is safe to use?

There are 12 horseshoe-shaped magnets behind the Gyro Drop’s seats and 12 metal plates on the central tower column. When the seats reach the top (about 70 m from the ground) and drop quickly, the magnet attached to the back meets the metal plates on the central tower column at 25 meters above the ground. An instantaneous current flows through the metal in the tower column, and as it becomes magnetic, a strong repulsive force is generated between them. Due to this repulsive force, the Gyro Drop can be stopped without any external force or physical contact! Isn’t it amazing?

Nothing is more important than safety for the rides in amusement parks. And the material responsible for this safety is none other than “steel.” If it weren’t for steel, there would be no thrill rides or amusement parks. Next time you’re on a ride, remember the hidden story behind it!

STEEL Talk presents to you interesting stories of Science, Technology, Energy, Environment, Life — and of course STEEL!

Have you ever seen a blast furnace? The picture below — molten iron pouring out from the blast furnace — might be familiar to you, and it could be the first thing on your mind when it comes to blast furnaces. However, seeing the blast furnace in real life isn’t a daily event.

The POSCO worker in the photo is clearing the area around the tap hole (an exit where the molten iron is discharged) so that the molten iron can smoothly flow out of the blast furnace. That is not easy since the discharged molten iron reaches over 1,500 ℃. However, POSCO employees can do this job owing to the pride and passion they possess for the blast furnace.

Iron ores become molten iron on entering the blast furnace. Then the molten iron is taken to the converter to filter all impurities. Next, the molten iron is shaped into large cuboids, which are then sent to different plants to be various steel products. This entire mechanism is called an integrated steelmaking process. The name says it all. It’s a process that flows continuously from the molten iron stage to the final steel product stage. So the entire blast furnace and steelworks are under operation 24/7 all through the year!

So, what if the blast furnace is idled? The blast furnace itself will be hardened into a huge mass of solid iron, so to restore the process and operate normally, it should be dismantled and replaced with a new one. The cost reaches 500 billion to 1 trillion KRW, and the reconstructing takes several months. Another problem is that it doesn’t end with just the blast furnace. As mentioned earlier, the steelworks is a continuous process, so if the blast furnace stops operation, all the plants that use the molten iron from the blast furnace need to cease their operation as well, meaning that the whole steelworks would have to be shut down.

That is why for the workers at POSCO, the blast furnace is like the subject of “sacred worship.” Did you know that torch lit with the sun was used to ignite the blast furnace No. 1 of Pohang Works in 1973? The records of POSCO history describes the moment very movingly, saying that “each torch relayers in turns took over the ‘flame of the sky.’”

▲ A sacred ceremony of the Olympic torch lighting in honor of Prometheus, who gave fire to humans. Inside the circle shows Tae-Joon Park lighting the torch with the sun to ignite POSCO’s first blast furnace (June 7, 1973).

As a result of this ceremony, the blast furnace has become a sublime object that must be protected for the POSCO workers. The commitment is as deep and heavy as the ancient Persian religion, Zoroastrianism, which cherished the fire used for rituals, and the people of the Stone Age desperate to preserve the flame which was obtained with much difficulty. The reason for this is because steel created with the ‘flame of the sky,’ laid the foundation for the development of the Korean manufacturing industry, and is everywhere in the advancement of the Korean economy.

There are some steelworks around the world where blast furnaces have been idled. As a result, other plants attached to it stopped operation as well, which led to the whole steelworks having to be shut down. As the steelworks were closed, the local economy collapsed as well, deteriorating the entire economy of a country eventually.

So idling the blast furnace is a big problem we need to pay attention because there is no simple solution when we look at the effects caused by it. If it’s shut down, the whole steelworks is closed subsequently. POSCO operates four blast furnaces at Pohang Works and five blast furnaces at Gwangyang Works, respectively. It is necessary to understand that if the furnaces stop operation, local economies might collapse as well. The consequence is enormous.

Although we’re not aware, our heart pumps and circulates blood throughout our body to keep us alive. POSCO blast furnaces are just like our ‘heart.’ They pour out molten iron 24/7 and help the economy of Korea ‘thrive.’

▲ A POSCO worker dealing with molten iron

POSCO’s furnaces are under operation based on cutting-edge technologies such as Big Data and AI. Due to this outstanding feature, POSCO was designated as a ‘Lighthouse Factory’ by the World Economic Forum (WEF) for the first time in Korea. When it comes to blast furnaces, the spirit of POSCO workers is still alive even in the high-tech world of today.

The answer to today’s question became a little serious, but we can’t help it. Because POSCO Newsroom — being a part of POSCO — also shares the pride and passion of the workers at the steelworks. POSCO Newsroom will be back with more interesting stories! See you next time!

* This article was written with help from Jun-Seok Park of POSCO Pohang Works Technology Development Section.

STEEL Talk presents to you interesting stories of Science, Technology, Energy, Environment, Life — and of course STEEL!

Anyone who doesn’t like getting deliveries? ʕ •ɷ•ʔฅ Probably none. In Korea, almost everyone — men and women of all ages — shops online and receives home deliveries. You can order anything and everything online these days — from clothing and electronics to even food! Then, is this possible for steel as well? That’s the question that flew into Newsroom today.

POSCO steel products are ordered and sent to companies that make the end products that people use — consumer products like mobile phones, cars, and refrigerators! When we receive parcel deliveries, it usually comes in a small box. Can you imagine how big steel could be shipped? POSCO Newsroom shows you how it’s done.

l Purchase POSCO Steel ‘Online’

▲ POSCO client companies buy steel through ‘e-Sales’ of [Steel-N.com]

Client companies can place orders directly through this site. When the order comes through, POSCO marketers look at the order form and checks if POSCO can produce the steel as requested, and also whether it can be delivered by the desired date. Then, they decide whether to produce the steel in Pohang or Gwangyang Works. Next, the system automatically checks the order with the marketers rechecking for any possible errors. After this process, the order is confirmed and then production begins!

While non-members can freely purchase products in general online shopping, an inquiry with client information is needed in advance to purchase POSCO steel. If a direct inquiry is hard, you can consider buying POSCO steel through a general trading company.

l How Is Such Large and Heavy Steel Delivered?

Have you ever seen a delivery truck in front of your house? You must have seen all the parcels stacked up inside. The items we order online are usually delivered by trucks. What about large steel? Well, POSCO’s steel could be sent on trucks, vessels, and even trains!

Once the steel is produced and its quality checked, it’s tightly packed according to its feature and the client’s request. The packing protects the steel from rain, abrasion, and other damages. The steel then leaves the warehouse in one of these three ways: land transport, sea transport, and rail transport, depending on the order.

Let’s suppose you ordered a box of fruit, and it was placed at the bottom of the parcel stack and delivered to you. Wouldn’t your fruit be scratched and bruised? This is why POSCO makes sure the steel is transported safely and appropriately so that customers can use them at the best quality. Now let’s look into the details of each transportation method.

Land Transport
Land transport is a way of loading steel onto cargo trucks and transporting them on roads. Best suited for short-distance transportation, this method is usually used in delivering to nearby areas. It’s easier to arrange than other modes of transportation, making it perfect for urgent deliveries. POSCO also makes a lot of steel that is too large to be transported by regular trucks, so there are special vehicles for this purpose. These vehicles enable the safe delivery of large-sized products.

Sea Transport
Sea transport is considered the most economical method since large amounts of steel — 3,000 to 5,000 tons depending on the size of the ship — can be transported at a single time. POSCO Pohang Works is located on the East Sea, and Gwangyang Works on the left side of the South Sea. So the location of both steelworks makes it appropriate for sea transport since the steel can be shipped to the docks as soon as production is complete. When shipping domestically, POSCO uses a specialized ship called, RO-RO (Roll-On, Roll-Off). Rather than having to ship products one by one, the steels are loaded on a truck in advance, and the truck itself is placed on the RO-RO ship. It makes the work process much more efficient. POSCO is exporting steel to numerous countries around the world as well.

Rail Transport
When transporting steel by rail, a ‘Special Freight Car’ is utilized. Products sensitive to moisture are transported using a freight car equipped with screens and waterproof curtains to protect products. Rail transport causes lower CO₂ emissions than land and sea transport. It’s also appropriate for pre-scheduled transportation and safer — since there’s a lesser risk of accidents.

As seen here, POSCO’s clients can use the online ordering system to order the steel they desire, as well as check the production and delivery process, just as they can with online shopping. Overseas deliveries and other special deliveries are no problem as well. That is all for today! If you have any questions about POSCO in the future, please send them to POSCO Newsroom!

* This article was written with help from Vin-Na Choi of POSCO Sales and Production Coordination Office

STEEL Talk presents to you interesting stories of Science, Technology, Energy, Environment, Life — and of course STEEL!

POSCO volunteered spreading silicate fertilizer at a farm in Gwangyang last year. Since POSCO is a steel maker, the connection with fertilizer might seem odd. However, steel and fertilizer are quite close — closer than we think. Let’s see how these two go together.

l What Is Silicate And What Is Slag?

To make iron, iron ore is first smelted in a large blast furnace. After this, the iron ore is separated into molten iron and stony by-product. This by-product is called a ‘blast furnace slag.’ A blast furnace slag has a specific gravity different from molten iron, so it is easily separable.

When slag is first separated, it looks like hot molten lava. So to cool it down, high-pressure water is sprayed on it. After it cools down, the slag takes a sand-like form, and this is called ‘granulated slag.’ The granulated slag is then dehydrated and pulverized into pellet-like shapes about the size of 2 to 5mm. This slag is rich in silicic acid (SiO₂), which is essential for rice farming, so it is made and utilized as a ‘silicate slag fertilizer.’

The main component of silicate fertilizer is silicon (Si). Silicon is not an essential component for plant growth itself, but it is a vital component for the rice plant since 5-10% of its weight is silicic acid — the rice plant is even nicknamed a ‘Silicate Plant.’ Silicon is the most abundant in soil, but because it doesn’t separate well, the rice plant can not absorb the silicic acid. That’s why you need silicate fertilizer. Silicate fertilizers provide the rice plant with silicic acid that is absorbable — enhancing its ability to withstand heavy rainfall, strong winds, and pests.

In Korea, rice that is sticky with a weak scent is generally considered ‘good’ rice. Silicate fertilizer lowers the protein content in the rice, improving the taste and enhancing the quality and standard of the rice.

Slag, which is a by-product of ironmaking at steelworks, contains 25-30% of soluble silicic acid. POSCO has contributed to increase farm income by continuously supplying slag to fertilizer companies since 1974, the year after the Pohang Works began operation. Did you know that all silicate fertilizer used in Korea is made from POSCO slag? In the past 45 years, a total of 13.76 million tons of silicate fertilizers have been supplied to domestic rice paddies.

l Make The Earth Greener

It is a known fact that greenhouse gas causes global warming. In terms of carbon dioxide emissions from the agricultural and dairy industries in Korea, the numbers add up to 21 million tons per year — with 29% accounting from rice paddies. The use of silicate fertilizer is set to help reduce the amount of greenhouse gas emitted.

Since rice is grown with water-filled into the paddies, the organic matters in the paddy soil break down into methane (CH₄). Research from agricultural experts states that the iron ions (Fe3 +) in the slag fertilizer reduce the methane concentration from the paddy fields by 15-20%. The fertilizer is also expected to contribute to the ultimate reduction in greenhouse gas emissions by 1.1 to 1.5 million tons per year in Korea!

Increasing the use of silicate slag fertilizer is helpful to all — farmers, fertilizer companies, and the whole environment. First of all, the fertilizer improves the soil quality, which in turn enhances rice quality and grades. This eventually leads to higher incomes for the farming communities. For the government, the use of fertilizer reduces methane gas from the paddies, decreasing the amount of overall greenhouse gas. Also, better rice taste boosts the consumption of rice, which increases the competitiveness of fertilizer companies. So silicate slag fertilizer is not only environmentally conscious but also beneficial to the whole society.

POSCO plans to expand the demand for silicate slag fertilizer and develop overseas export markets so that the by-products are recycled well all around! (๑❛ᴗ❛๑)

[See more about the use of by-products here!] POSCO’s Eco Driver: Steel 2

* This article was written with help from Keon-Mok Sohn of POSCO By-Product Recycling Group

STEEL Talk presents to you interesting stories of Science, Technology, Energy, Environment, Life — and of course STEEL!

Magnets attract iron, and because of this, they are utilized in various forms. There are a lot of magnets that we can see in our daily lives as well — like the tiny magnets on souvenir magnets that stick on the fridge door, magnetic snaps that help items close tightly, and so on.

But if iron is in our body, why aren’t we attracted to magnets? Let see the reason in detail.

 l Iron — Essential for Our Bodies Too!

We can not live without oxygen, and it is the red blood cells that deliver this oxygen to cells all over the body. A molecule called hemoglobin in the red blood cells contains iron. Oxygen sticks to the iron here and moves around the body. So we can say iron is essential in our lives not just because of the benefits it provides, but because it carries oxygen around our body, thus making us stay alive.

Now that we know we have iron in our body, the next question might pop up — “Will magnets attract blood because of the iron in it?” Many scientists also had this question and have got the answer. Because if magnets do attract blood, we must be careful of the magnets around us!

Fortunately, the iron in our blood isn’t attracted to magnets. Iron is almost everywhere in our body but in tiny quantities. The amount of iron in an adult’s body put together is 3.5g. The iron contained in blood only is just 2g. This small amount is spread all over the body, so obviously, it isn’t greatly affected by the pull of magnets.

But this explanation isn’t perfect. Because in the case of super magnets, it could attract any magnetic substance no matter how small the amount is. So let’s find out a more accurate reason for this!

l What Keeps Our Body Safe From Magnets?

Hemoglobin molecules that contain iron tend to repel from the magnet when attached to oxygen. In contrast, oxygen-depleted hemoglobin molecules are attracted slightly by magnets.

A Youtube creator arranged an experiment regarding this explanation as well. Take a look at the real experiment! (Korean)

Hemoglobin in our blood is mostly attached to oxygen. Also, blood is composed mostly of ‘water,’ which tends to repel from magnets. So even if you put a strong magnet close to your body, you can see your body moving away rather than sticking to it. Isn’t it amazing?

You’ve probably seen an MRI (Magnetic Resonance Imaging) equipment in hospitals or medical dramas. An MRI is a device that lets you see inside the body using powerful magnetic fields. If blood is attracted to the magnet, the person inside the MRI would be in grave danger. However this never happens because the iron-containing blood doesn’t respond very much even to a powerful magnet. Also, blood circulates the body moving swiftly in the blood vessels, so the effect of the magnet is reduced even more! So don’t worry!

Was the answer satisfying? Just like the various steel products made by steelmakers, such as POSCO, make our daily lives more convenient and happier, it is important to remember that iron in our bodies plays an important role too! That’s all for today! See you next time! Bye~!

* This article was written with help from science communicator Jung-Wan Mok, and Youtube creator <Gwa Bboon Ssa>

STEEL Talk presents to you interesting stories of Science, Technology, Energy, Environment, Life — and of course STEEL!

Your dad was right to call Earth, ‘a planet of iron.’ Our planet was born about 4.6 billion years ago. It’s said that small planets — made up of rocks or metal masses — collided and merged to form the Earth. In the beginning, Earth was nothing more than a ball of hot magma, and as it gradually cooled down, iron and nickel that are relatively heavier sank to the bottom of the Earth, while lighter rocks rose to the surface and formed the crust.

Now, this is just a plausible hypothesis since no one saw this entire process. However, these two things are for sure — Iron has been on Earth ever since the beginning, and it has also played a significant role in human civilization. So, let’s look into the details!

l The Role of Iron In Our Civilization

Mankind advanced into the Iron Age from the Stone Age and the Bronze Age. Iron was stronger than bronze and readily available in nature, making it suitable as materials for tools. The iron beads of Egypt — made around 4,000 B.C. — was the first item humans made with iron, and the Iron Age arrived at around 1,000 B.C. Do you know what age we are living in today? Surprisingly, we are still living in the Iron Age. So this Iron Age has lasted more than 3000 years!

Before the Iron Age, humans dug into the ground to make houses, or crushed and cut out stones to build dolmens or pyramids. But as civilization evolved into the Iron Age, humans started making buildings using iron since iron was strong enough to make living space much safer and more stable. Before iron came along, most materials used in buildings were stones, bricks, and wood. So there was a high risk of tall buildings to collapse — since these materials were quite heavy, the weight was tremendous. But as iron emerged as the main material of architecture, constructing tall buildings became possible. The sturdy steel columns could support the weight of those buildings.

▲ The tallest skyscraper in Korea, Lotte World Tower! POSCO’s steel were used here!

Have you been to the Lotte World Tower(555m) in Seoul? It is the tallest building in Korea and the fifth tallest in the world. To build skyscrapers you need super strong and tough iron. That’s why POSCO’s own latest high-performance heat-processed ‘High Strength Steel’ was used in the construction of the Lotte World Tower. Thanks to the strong, durable steel, it was possible to create such a wonderful, tall architecture. As you can see here, iron and steel make the city safe and attractive with its role in the construction. We can also encounter steel in so many areas of our daily lives — like the buses and cars we ride, and the frying pans and cutlery of the kitchen.

l Iron — In Charge Of Life On Earth !

Can you guess the element with the largest mass on our planet? It’s ‘Iron(Fe).’ It accounts for 35% of Earth’s weight. But if you take a look around, it’s hard to understand this statement — there just isn’t that much iron around. Then, where is all that amount of iron? Well, it’s all hidden under the ground. As mentioned earlier, iron is a heavy material, so all of them sank to the Earth’s core.

The iron in the core has a significant role. It creates Earth’s magnetic field. Telling the North and South poles on a compass to find directions is possible because of this. A magnetic field is generated by conductive and magnetic materials, such as iron or nickel. The iron — in a liquid state at the core of the earth — creates the magnetic field as the earth rotates.

We can use a compass and also see the beautiful aurora at the poles, all thanks to Earth’s magnetic field. Not only that, but it also protects the Earth from the strong energy — the solar wind — of the sun. Without iron and its magnetic field, the Earth would have been a life-less planet, like Venus. So we are all alive here on Earth, thanks to iron!

Now you know why Earth can be called ‘a planet of iron!’ POSCO Newsroom will be back with a new and exciting story soon! Bye-bye ~! (*•̀ᴗ•́*)و ̑̑

* This article was written with help from researcher Eung-soo Choi of POSCO Technical Research Laboratories