Are you planning to use recycled steel for a green building project but don’t know where to start?
Or, are you curious about the sustainability benefits of recycled steel over its primary counterpart? Either way, you probably have a few recycled steel FAQs you’d like answered to help you make the right decision.
Recycling building materials like steel reduces carbon emissions while diverting waste from landfills. The use of recycled steel contributes toward sustainable construction by significantly reducing the over 1.4 tons of carbon emitted from manufacturing each ton of crude steel.
Furthermore, recycled steel conserves non-renewable resources like limestone and coal that go into making virgin steel, and avoid the pollution often caused by mining to obtain the iron ore and coal used in the manufacture of new steel.
In the rest of this article, I’ll answer some common recycled steel FAQs to find the solutions to your most pressing construction questions. This will help you understand why recycled steel is the best option for your sustainable construction project. Stay tuned!
Recycled steel is as strong as new steel.
According to the World Auto Steel Organization, steel doesn’t lose its properties when recycled. It can go through remelting and recycling without losing its tensile strength and durability.
The fact that steel is magnetic contributes to its ability to be recycled without compromising its strength. This feature allows it to be separated from other materials like aluminum during recycling.
There are many facts you should know, both environmental and economic, about steel recycling.
The table below summarizes some important facts about recycling steel:
|Recycled Steel Fact||Answer|
|Amount of steel recycled||81% from all industries globally|
|Energy conservation per ton (2,000 lb) of steel||60 to 74 percent|
|Coal conservation per ton (2,000 lb) of steel||1,400 pounds (0.7 tons)|
|Iron ore conservation per ton (2,000 lb) of steel||2,500 pounds (1.25 tons)|
|Steel cans recycled per second in the U.S.||Over 600|
|Water consumption reduction||40%|
|Water pollution reduction||76%|
|Mining waste reduction||97%|
|Air pollution reduction||86%|
Table 1: Key facts about recycling steel compared with manufacturing new steel from iron ore.
Steel can be recycled repeatedly without losing its strength and durability because it’s 100% recyclable.
The material’s magnetic nature makes it possible to efficiently separate steel scrap for recycling from other metals present in the waste stream.
That said, it’s worth noting that a competent company must handle the recycling process to avoid contamination of the waste stream with other materials.
According to a recent study, recycled steel in the U.S. is worth $415 per metric ton.
However, the price of recycled steel fluctuates based on market conditions like supply and demand, the availability of raw materials, and production costs.
Despite the fluctuations, recycled steel is cheaper than its primary counterpart. Its production doesn’t involve as much energy-intensive processing or excessive consumption of natural resources. Therefore, you’ll get the best value for your money if you opt for recycled steel over its virgin counterpart.
Galvanized steel can be recycled.
The material is easily recycled in electric arc furnaces with temperatures over 3,500°C (6,332°F).
During the recycling process, the zinc coating present on galvanized steel volatilizes before the rest of the metal. Therefore, it’s collected earlier and recovered for use in the production of other refined steel products.
After the collection of stainless steel scrap (industrial scrap, reclaimed scrap, and new materials), it’s taken to the recycling plant for processing.
Once in the plant, stainless steel is recycled in the following process:
- Shredding: A recycling processor transfers the scrap into shredders for shredding into smaller pieces for efficient handling.
- Chemical analysis: Analyzing the scrap to know its composition and grade before sorting it into piles based on alloy content. The process may involve blending the shredded scrap into nickel alloys, chrome steels, and other stainless steel-based components.
- Melting: After sorting, the scrap is melted in an electric arc furnace or induction furnace at over 3,500°C (6,332°F).
- Refining and separation: Non-metallic elements are removed from the molten steel while alloying materials like nickel, manganese, and chromium are added. Chemical analysis is also conducted to make final adjustments for the expected refined stainless steel product.
- Solidification: The refined material is transferred into cooling chambers. Here, it’s cooled and molded into the desired shape.
- Finishing: The finished product is polished before being shipped to customers for manufacturing, construction, and other uses.
Recycled steel is used for construction, motor vehicle production, machinery, food containers, ships, pipes, bridges, and railways.
Most of the steel products sold today contain approximately 60 percent recycled steel and 93% of structural steel is recycled.
At the time of writing, you get $199.63 on average for recycling a metric ton (2,205 lb) of steel in the U.S. The amount you get varies depending on your steel scrap’s purity, grade, and type.
The type of steel scrap can either be ferrous or non-ferrous.
Non-ferrous steel scrap will fetch a higher price than its ferrous counterpart. This is because there is high demand and poor supply for non-ferrous scrap.
Approximately 81 percent of the steel from all industries is recycled. This recycling rate makes steel the most recycled material globally.
However, it’s worth noting that because more steel is produced than scrapped, recycled steel comprises approximately 40 percent of total steel production.
In terms of numbers, over 1,085 million metric tons of steel are recycled annually.
What Is Recycled Steel?
Recycled steel is a more eco-friendly material than new steel and is produced using scrap steel from discarded steel components at the end of their lifecycle.
The material helps reduce greenhouse gas emissions and conserve natural resources like iron ore, limestone, and coal. It achieves that by reducing the demand for primary steel manufacturing, an energy-intensive process that uses more non-renewable resources.
Moreover, primary steel production contributes immensely toward environmental degradation through opencast mining.
Carbon steel is recyclable because all steel is iron alloy.
An iron alloy comprises metals and non-metals like carbon, tin, and iron. These components are highly recyclable due to their ability to retain structural properties.
It’s worth noting that carbon steel produces items like cans, tools, and car bodies due to its strength.
It’s a strong metal that can be recycled multiple times without compromising its strength and durability.
Steel can be recycled by collecting and sorting scraps based on their purity. The collected steel scraps are then taken to a recycling plant for further processing and recycling.
At the recycling plant, the steel scraps are melted in furnaces running at approximately 3,500°C (6,332°F).
The molten material is then purified to remove contaminants before being poured into molds to create the desired product.
Eighty-one percent of steel from all industries is recycled, making it the most recycled product worldwide.
In terms of numbers, over 1,085 million metric tons of steel are recycled annually. This accounts for more than 40 percent of the total production in the global steel industry.
The high recycling rate of steel is based on its sustainability. The process conserves energy and other natural resources while preventing environmental degradation.
Steel should be recycled to promote sustainability. Here are the sustainable benefits of recycling steel:
- It conserves between 60 and 74 percent of the energy used to produce primary steel.
- Recycling a ton (2,000 lb) of steel prevents the emission of 1.67 tons (3,340 lb) of carbon dioxide.
- It conserves natural resources like coal, limestone, and iron ore.
- It prevents environmental degradation through open-pit mining.
- It diverts waste from landfills.
Rusted steel can be recycled because rust doesn’t affect structural properties.
Rusted steel is heated, melted, and refined at the recycling plant to remove impurities like dirt and oil.
The smelting process also breaks any bonds between rust and steel. Therefore, the end product is pure recycled steel ready for repurposing.
Mild steel can be recycled because it contains iron. This material, also known as plain-carbon steel, has a low carbon content of 0.05 to 0.25 percent.
Mild steel is used in different applications such as structures, fences, wires, car bodies, and furniture frames.
As with all steel, recycling mild steel conserves energy and other natural resources while preventing environmental degradation.
Recycled steel is sustainable since it conserves energy and non-renewable resources.
Moreover, recycling steel prevents the emission of greenhouse gases like carbon dioxide, nitrogen oxide, and sulfur dioxide from the production of new steel.
Finally, recycling steel conserves the environment by eliminating deforestation and land degradation caused by opencast mining.
It’s worth noting that the recycling process also creates more job opportunities, boosting economic sustainability.
The advantages of recycled steel include:
- Conservation of energy and natural resources.
- Elimination of air and water pollution due to mining.
- Reduced greenhouse gas emissions mitigating global warming.
- Increased job opportunities in the steel recycling industry.
- Lower risk of environmental degradation.
- It remains strong and durable after recycling.
- Elimination of soil erosion by conserving trees and the topsoil.
- Cost savings due to lower production costs.
- Reduction in landfill waste and other issues caused by the accumulation of scrap materials.
The disadvantages of recycled steel include:
- Transportation to take the materials to the recycling facility. This increases the number of carbon-emitting vehicles on the road.
- The process of sorting and melting steel is labor-intensive and still requires energy.
- The raw materials used in the production of recycled steel are limited since they come from scrap materials.
- There’s a possibility of recycled steel containing trace impurities or contaminants that can affect its structural integrity. However, this is addressed during production with appropriate quality control measures.
The carbon footprint of recycling a ton (2,000 lb) of steel is approximately 0.18 metric tons (396.83 lb). This is because manufacturing a ton (2,000 lb) of primary steel emits about 1.85 metric tons (4,078.55 lb) of carbon. On the other hand, recycling a ton (2,000 lb) of steel prevents the emission of 1.67 metric tons (3681.72 lb) of carbon.
Therefore, recycling steel is a great way to reduce your carbon footprint and contribute to a more sustainable environment.
Like any other metal, recycled steel rusts due to environmental conditions.
Rust results from a chemical reaction when metal is exposed to moisture and oxygen.
You can prevent rust by storing your recycled steel in a cool, dry place.
If you need to use recycled steel materials outdoors, ensure they are galvanized (a process that coats the steel in zinc) to protect against the elements.
Steel doesn’t lose its properties when recycled and, thus, can be recycled repeatedly.
This is due to the following factors:
- Metallurgical properties: Steel comprises carbon, iron, and other elements. Steel scrap is melted and purified in a controlled environment to attain the same metallurgical properties as primary steel.
- Homogeneity: Steel is a homogeneous material with consistent properties throughout its structure. Therefore, recycling doesn’t separate its components.
- Recycling efficiency: Over the years, there has been advancement in recycling technology that has improved the efficiency rate of recycling. The efficiency ensures that recycled steel is high quality and has similar properties to primary steel.
- Refining: Steel undergoes refining during recycling to remove impurities. Therefore, the resulting product is highly consistent and the same quality as primary steel.
Recycled Steel FAQ – Final Thoughts
With this list of recycled steel FAQs, you now know more about the benefits and drawbacks of recycled steel.
Recycling steel is a viable way to conserve energy, natural resources, and the environment. It’s also cost-efficient, durable, and strong enough for many different applications.
However, like anything else, recycled steel is not without its drawbacks and these must be weighed up to ensure it’s the right material choice for your project.
That said, the benefits of recycled steel almost always outweigh its drawbacks, making it an excellent way to conserve the environment and build high quality structures.