Reinforcing steel is made from scrap. This is good, because it means that a lot of 'waste' is reused. Good for the environment. The importance of this is becoming increasingly clear. So it's a good thing that recycling is possible!
When you start making reinforcing steel from a refrigerator or a car, or any other former product, that means that there will be impurities in the steel. After all, it is recycled material. It is not made from clean iron ore.
Then you wonder what the impurities are. And whether there are differences when you look at the origin of the reinforcement steel and the impurities it contains. And how we should deal with this. After all, we all want to continue to live on this planet for a while.
University of Tokyo
Betonstaal.nl contributed to a study on impurity levels that compared impurities in steel scrap internationally. The study was carried out by the University of Tokyo in cooperation with Leiden University, where Benjamin Sprecher participated in the research.
Steel scrap is a good step in the fight against climate change and the transition to a circular economy.
When you look at the process, it is not only important how high the recycling percentage is, but also how high the quality of the secondary materials is. In other words, the original products from which the reinforcement steel is made. The scrap has various origins and the accumulation of impurities in the recycling process affects the quality of the steel. When you think of the circular economy, in which recycling will increase more and more, these impurity levels are crucial to know.
So it is a very good thing that this research took place!
More than 500 reinforcement bar samples were compared in the study. Betonstaal.nl supplied 100 of these.
The research showed that the following elements play a role in the level of impurities:
This makes the study complex, as the accumulation of impurities in steel is influenced by several variables.
It can be concluded from the study that the level of impurities in steel scrap is not uniform between countries. The content was found to be higher in Western Europe and Japan, especially in the case of copper and tin, than in Ukraine, Vietnam and China.
By communicating the chemical composition of scrap, cooperation between the recycling and steel industries can be strengthened to match supply and demand and increase the proportion of scrap in steel production. Information about the chemical content of scrap could be the next step in that cooperation.
By introducing quality control, recycling facilities can provide information about the quality of scrap, guarantee a standardised quality grade or even meet specific requirements for steel production.
For steel producers, knowledge of the chemical composition of scrap can contribute to a larger share of secondary inputs.
In short, the study clarified the steps that can be taken to give scrap recycling an even greater place in the rebar of the future.
You can read the entire study here: https://onlinelibrary.wiley.com/doi/10.1111/jiec.13246
