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4. Efficient use of resources and high recycling rates

Now more than ever, we are focused on understanding the full life cycle of materials and products. Steel is at a distinct advantage, as the most recycled material in the world – more than aluminum, paper, glass, gas and plastic combined. This is because steel is infinitely recyclable, meaning that it can be recycled indefinitely without compromising its quality. As a result, steel plays an important role in the circular economy. 

Why is this important to us?

In recent years, a greater emphasis has been placed upon the reuse and recyclability of all materials. Steel is everywhere in our daily lives, and we must highlight all of its advantages. As the leading steel provider in the U.S., we carry the responsibility of maximizing our efficiency and recyclability. 

The commercial imperative

What kind of challenges do we face?

Many of our stakeholders are not fully aware of steel’s contribution to the circular economy and its inherent life cycle advantage. As a result, competing materials pose a challenge to our leadership in the market. In addition, we must continue to utilize all of our materials in the most efficient ways possible and find new ways to maximize our reuse or recycling.    

What do we need to do?

We must continue to drive process innovation, as it is the key to using our resources in the most efficient ways possible. We must also collaborate with our stakeholders, including our customers, the government and our local communities, to better inform them of steel’s life cycle advantages and to encourage higher end of life recycling rates for products made from our steel. 

What is the potential to create value?

Steel will always be a leader due to its high recyclability rate. When steel is recycled, we minimize our use of natural resources, decrease our emissions and reduce our overall environmental footprint. We have the opportunity to create additional long-term value through continued innovation and stakeholder collaboration. 

Recyclability of steel

Recyclability of steel

Steel is the most recycled material in the world. Since 1988, more than one billion tons of steel have been recycled by the North American steel industry, according to the American Iron and Steel Institute. There are typically 60 to 80 million tons of steel scrap recycled per year into new steel products in North America. When steel is recycled, 74 percent of the energy that would be used to create steel purely from raw materials is conserved. In addition, every ton of steel recycled conserves 2,500 pounds of iron ore, 1,400 pounds of coal and 120 pounds of limestone. Production through an integrated steelmaking facility allows for high quality steels that are able to meet more advanced applications.

In total, 29 percent of each ton of steel produced by ArcelorMittal in the U.S. is from recycled scrap steel.

Beyond the recycling of steel itself, ArcelorMittal also recycles many coproducts and byproducts of the steelmaking process. Some byproducts, like mill scale, steelmaking oxides and beneficiate steelmaking slags fines can be recycled to a certain extent right on site through sinter plants to make iron-bearing raw material for our blast furnaces. Others, like coal tar or ammonium sulfate from the coke plants, are highly valued as raw materials in the chemical industry or for use as fertilizers. Blast furnace and coke oven gas is captured and used to create electricity and steam.

One of our highest volume byproducts is steelmaking slags. We have begun to market this byproduct to the cement industry as a raw material as well as for reuse in fertilizer.

Another excellent example of our recycling efforts is seen in our reuse of slag and sludge within our steelmaking process. Recent innovations by our research and development team are allowing us to reuse more of these resources onsite. The sustainability benefit is significant, as we are able to greatly reduce costs, landfilling and the consumption of virgin raw materials: iron ore and fluxes. In addition, slag can also be recycled into new products, which include:

  • Dark colored glass, including medicine and beer bottles
  • The mineral wool industry, including ceiling tiles, insulation, fire proofing and sound proofing
  • Concrete blocks
  • Construction applications, including heavy highway and bridge materials, base for roads, concrete, hot mix asphalt and under drains for piping


VIDEO: Environmental stewardship through recycling

ArcelorMittal USA recycles product--not just steel, but also the byproducts of steel that end up in places you might never have thought.

 

 

 



2016 Highlights


29 percent of each ton of steel produced by ArcelorMittal in the U.S. is from recycled scrap steel.

When steel is recycled, 74 percent of the energy that would be used to create steel purely from raw materials is conserved.

 

Every ton of steel recycled conserves 2,500 pounds of iron ore, 1,400 pounds of coal and 120 pounds of limestone.

Case studies: Recycling and reuse

Extracting iron from blast furnace byproducts reaps benefits

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Like many steelmakers, ArcelorMittal Burns Harbor produces byproducts that contain valuable iron units, yet not enough to be recycled directly back into our operations. The Burns Harbor iron producing department has initiated a separation process where the high-value iron material can be extracted and used in the blast furnace. 

“This creates a win-win situation, as we get a very inexpensive iron source for the blast furnace that’s half the cost of an iron pellet, and we are able to minimize our environmental footprint at the same time,” said Doug White, lead engineer, operating technology, iron producing, ArcelorMittal Burns Harbor. “We’re in the early stages of this project, producing about 6,000 tons a month with hopes to improve on that number in the future.”

The process has been developed jointly by ArcelorMittal Global Research and Development and other service providers. It’s been successful at producing a useable product in the blast furnace that has more than 70 percent iron, where a typical pellet would contain about 65 percent iron.

“The product we are putting into the blast furnace is less than half the price of a pellet, so every ton of this material we use saves about $50,” said White. “Another cost benefit is that this high-iron material has a relatively low slag volume in the blast furnace. This saves coke rate in the furnace and produces more iron in the blast furnace than what could be produced with just pellets alone.”

White says there are also energy benefits to this process. The material that goes into the blast furnace – called metalized material – has only to be melted and not reduced like an oxide material. When it gets to the blast furnace, the material is able to be processed into pig iron at a lower energy (fuel) rate than iron oxide pellets.

While there are no start-up costs for this iron extraction process, White said that the service provider does charge a fee for processing the material. Our Indiana Harbor facility is also starting to utilize this process. 

“There are also long-term sustainability benefits as these materials are returned directly to the process. So while the program is still in the infancy stage, we’re seeing many possibilities and benefits from re-using this recycled material,” added White.

“After many tries to identify a viable separation process to recover these valuable iron units that is cost effective, it’s gratifying to see these preliminary results that seem so promising,” said Dale Heinz, senior division manager, primary operations, ArcelorMittal Burns Harbor. “It seems a long time in the making, but this recycling breakthrough promises significant economic benefits to the company.”

VIDEO: Recycling byproducts at ArcelorMittal Burns Harbor

Iron oxide and mill scale: recycling our byproducts for everyday use

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The steelmaking process requires significant raw materials. As these materials are transformed into steel, a number of byproducts are created. To reduce our waste, we seek ways to recycle and reuse these byproducts whenever possible.

For example, 4 percent of the mixture included in a cement kiln is iron. The presence of iron reduces the temperature at which the cement reaction can take place, thereby resulting in less energy consumption and less wear and tear on the refractory kiln. 

Some cement kilns are located near a limestone quarry that naturally has enough iron required to optimize the reaction process. Those kilns do not add extra iron to the kiln. Other companies, however, make cement out of limestone that is low in iron. Those kilns must have added iron-rich material to lower the temperature for the reaction.

That’s where ArcelorMittal comes in. In our process, not all iron is converted into steel. Some is converted to iron oxide and recovered through the fume collection system. This material is a dry dust that is a fairly pure form of iron oxide. In many cases, this iron oxide cannot be reused in blast furnaces. At Indiana Harbor and Riverdale facilities, we avoid landfilling this byproduct by selling micro pellets of iron oxide to cement companies. The process for making these pellets is relatively simple: we add a binder (ironically often cement) to iron oxide and mix it in a kiln onsite. As the oxide, moisture and binder tumble together in the rotating kiln, the material turns into spherical pellets that we then sell to cement companies.

It costs ArcelorMittal approximately $15 to make 1 ton of micro pellets, more than the $10 per ton price of the pellets we sell. This is more cost effective than the landfilling alternative, which totals $35 per ton. This saves the company money and helps us to use resources most efficiently. 

In addition to iron oxide, ArcelorMittal also recycles mill scale from our Indiana Harbor East and Cleveland plants. During the steelmaking process, heated slabs are red hot, and when the slabs are rolled, the outer “skin” come off as mill scale. While some mill scale can be recycled into the sintering process, we try to sell the rest. 

Mill scale can be pressed into sheets and reused as a counterweight for filing cabinets. With a sheet of very heavy material in the back of the filing cabinet, the center of gravity is close to the wall and therefore the drawer won’t tip over. This same counterweight effect using mill scale can also be found in stadiums and sports arena seats. Mill scale in the back of the seats ensures chairs flip up automatically. 

While iron oxide and mill scale are not harmful materials, they do accumulate and must be either landfilled or reused. William Sammon, manager, procurement, at ArcelorMittal Indiana Harbor, explains that, “We try to think about the properties of our byproducts and educate ourselves on what industries require materials with such properties. With research, knowledge of the market, and listening to others, we figure out how we can provide a customer with something valuable while also recycling our own byproducts and enhancing our efficiency.” 

In an effort to be more sustainable, we are dedicated to figuring out who would consider our byproducts to be raw materials in their processes.