The Steelmaking Process

So, what does a blast furnace do in the steelmaking process? There are 4 main parts to the process of making steel, and in each process, the accompanying production equipment is as vital as the materials that make steel. Each batch of steel starts off with iron, molten iron to be exact, and the blast furnace is what transforms raw materials into molten iron.

Molten iron leaves through the bottom of a blast furnace

Molten iron comes from two raw materials; iron ore and coal. First, iron ore is converted into sinter ore in a sintering plant and coal is converted into raw coke using a coke oven. The processed materials are then poured into a blast furnace through the top opening. Hot air reaching 1200℃ is blown in from the bottom through tuyeres and chemically reacts with the materials as they fall to the bottom of the blast furnace. This process oxidizes the coke and reduces the sintered ore, creating molten iron. The molten iron is then further processed to make steel.

The Importance of the Blast Furnace

The Blast furnace is one of the oldest and most significant equipment in the steelmaking process. The average lifespan of a blast furnace is about 15 years before it needs to be replaced or refurbished.

The Pohang No.1 blast furnace

POSCO is a few months shy of its 50th anniversary, and the Pohang No.1 blast furnace has been in operation for 45 of those years. Interestingly, the blast furnace has never broken down or gone out of service. With an annual capacity of 1.3 million tons, it helped establish Korea as the top-5 steelmaker in the world and was even named Korea’s Economic National Treasure No.1.

A New Technology from an Old Furnace        

In the beginning of 2017, POSCO decided to shut down the Pohang No.1 blast furnace for good in response to the slowing steel market and put the national treasure in a museum instead. It seemed the oldest operating blast furnace in Korea would finally retire.

However, just before pulling the plug, engineers used the Pohang No.1 blast furnace in a pilot operation program using low-grade raw materials such as soft coke and low-cost iron ore to produce molten iron. To everyone’s astonishment, it succeeded, and with lower charter costs than the larger blast furnaces that have 3 times the production capacity.

As it turns out, because of its smaller size, the blast furnace can operate with low-grade raw materials such as soft coke and low-cost iron ore, and can flexibly adapt to fluctuations in operations. Employees further developed the technology and as a result, Pohang No.1 blast furnace recorded the lowest charter costs of all POSCO blast furnaces in April this year.

Thanks to the new-found technology, the legacy of the Pohang No.1 blast furnace will continue.

What’s the Secret to Longevity?

Usually, a blast furnace needs to be sprayed down every 6 months so that it does not get damaged from temperatures that can reach up to 2000℃. The bottom of the blast furnace is where the heat is concentrated, thus most susceptible to damage. Furthermore, fluctuations of the internal gas composition can lead to explosions. To solve this problem, POSCO’s technicians developed a technique to lower the coke to below the tuyere and repair the bottom of the blast furnace. This technology was applied to other furnaces and maintenance systems and is still in use today.

The Pohang No.1 blast furnace’s TFT during maintenance

To add, the Pohang No.1 blast furnace even has its own voluntary task force team (TFT) to care for and maintain the blast furnace called “Love for the blast furnace, love for POSCO.” The team of 15 not only makes sure the blast furnace is operating smoothly, they also continually research new technologies to prevent malfunctions and enhance the blast furnace.          

In a matter of months, the furnace went from almost becoming an artifact to a central part of POSCO’s competitiveness. This blast furnace’s long history in itself is impressive, but with its recent transformation, there is no telling what greater innovations and technology POSCO will achieve.

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With the emergence of the 4th industrial revolution as a hot topic of the world economy, AI is expected to drive manufacturing innovation by providing breakthroughs in smart factories.

POSCO Smart factory in Gwangyang

In his recent POSCO Issue Report, Kim Ho-In, a senior researcher at POSRI, examined what innovations AI can bring to the upgrowth of smart factories, and identified key issues related to such technological introductions.

Smart Factory Takes Wing with AI

Kim looked at how AI will provide breakthroughs in areas of manufacturing, such as preventive system maintenance, process control, expert process control and robot automation, and how AI  will make smart factories more efficient, less wasteful and more productive.

Traditional stock, inventory and statistical analysis provided insufficient information for preventing factory defaults, and made certain failures inevitable. With AI, however, factories can predict quality deficiency, gather and analyze complex data and improve equipment reliability. Also, by integrating such intelligence with robots, there are now self-learning, versatile beings that can automatically overhaul and optimize system defaults.

Thus the ability to self-teach, analyze and create will lead to a more comprehensive statistical analysis and achieve positive results in preventive maintenance.

The Right Kind of Smart

The different innovative tools in smart factories, however, may have distinct values depending on its application for the industry in question, so while such technological advances may be a breakthrough for manufacturing, companies must apply the tools that are most effective for their field and industry.

AI that can self-teach, analyze and create in a smart factory

For instance, the technology required for “smartization” is entirely different for assembly process industries such as parts production, automotive and electronics, than from mechanisms industries such as metals, chemicals and energy.

In the assembly process industries, customizing production, cutting labor costs and responding to the fast life cycle of products are the major areas for innovation. AI applications like robot automation can guarantee positive results because many production processes can be replaced with robots, resulting in minimized labor costs.

In the process equipment industries, however, improving productivity through optimal control of core processes, controlling the linkage between processes and maintaining the facility are the major issues. The loss of data can be extremely critical in the case of a core facility failure, so preventive equipment maintenance would have a greater impact than robot automation.

The investment size and outcome value for implementation and innovation of smart factories will differ by industry. Thus it is necessary to build up strategies on technologies that are most suitable for each required field.

Smart Reconstruction

Recently, the world’s fifth largest blast furnace located in Pohang Works, went through major renovations to “go smart”. The Pohang Blast Furnace No.3 was first fired up in 1978 with an internal volume of 3795㎥, and was repaired in 1989, 2006 and finally in 2017, when it leaped toward POSCO’s vision of “smartization”.

After a 102-day repair period, the furnace volume expanded to 5600㎥, and the site is now fully equipped with AI to precisely monitor the condition of the blast furnace.

The Blast Furnace No.3 dismantled at the start of the repairing process

Engineers, including Gi Wan Son, Blast Furnace No.3 Repair Quality PJT team leader, worked on all three renovations and provided exceptional knowledge based on more than 40 years of experience with the Blast Furnace No.3. According to Son, the main focus was to build a smart technology infrastructure that utilizes AI and collects big data.

POSCO added smart sensors that automatically monitor the internal state of the blast furnace such as raw material quality and ventilator status. Both measures are expected to help forecast and extend the lifespan of the blast furnace to longer than the average period of 15 years.

[clickToTweet tweet=”POSCO Blast Furnace No.3 will lead the future of  blast furnaces for another 50 years if we incorporate POSCO’s advanced technologies” – Gi Wan Son, Blast Furnace No.3 Repair Quality PJT team leader” quote=”POSCO Blast Furnace No.3 will lead the future of  blast furnaces for another 50 years if we incorporate POSCO’s advanced technologies” – Gi Wan Son, Blast Furnace No.3 Repair Quality PJT team leader” theme=”style6″]

Though in its early stages, AI has already had a significant impact on smart factories and further innovations are expected. The manufacturing industry needs to pay close attention to the future scope of AI development and how it will allow them to overcome existing challenges and open doors to a limitless future.

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