JAES Learning

Electric Furnace - Direct Reduced iron (HBI) - the future of steel

Index:
Introduction on scrap, from what it is obtained, in which sector.
Electric furnace technology utilising scrap.
Electric furnace benefits for the environment.
Future scrap shortage, scrap data sorted by country.
Scrap, what it is, how it is produced, advantages.

Have you ever thought about the destiny of vehicle wreck? For example, what’s the destiny of dismissed military tanks or your cars?

The majority of these vehicles components are composed of steel, resistant and abiding irony material, capable of resisting crashes and corrosion.

In our previous video we showed you steel’s history and its features, the various type of steel existing nowadays and how to produce it. But with this new video we want to show you its most important feature, which is recyclability.

Let’s take our tank as an example, an armoured, blast-resistant vehicle composed mostly of alloy steel plates, as we can see here. From this technical division, we notice that there are many parts made of steel, and the same goes for cars, in which the chassis with its uprights are all made of ultra-high-strength steel.

All these components in different types of steel, once they fall into disuse can easily become material for the production of new steel; that’s when steel scrap comes into play. Scrap steel is nothing more than steel scraps that are used by steel plants using electric furnaces to produce clean steel.

Now let’s talk about the whole steel production chain to better understand the use of steel scrap.

Basically, there are two big categories: steel plants using blast furnaces and steel plants using electricfurnaces.

For the first category of steel plants, blast furnaces use guarantees a wide production of steel thanks to the furnace’s capacity. In fact, this is a complex process which implies raw materials like iron minerals and limestone to be united with coke to obtain cast iron, subsequently becoming steel by using a converter. Moreover, this process creates big amounts of polluting substances, especially CO2, throughout its different stages. The process is very polluting since the beginning: for example, coke plants need to burn high quantities of fossil carbon in order to produce the coke needed. Doing that, they emit enormous quantities of CO2. For this process, steel scrap is only used during the last stage, when it is added to cast iron in the converter in order to increase the steel purity.

For steel plants that use electric furnaces, the process is very different; the material used by these plants is limited to just one, the scrap steel indeed. With graphite electrodes, in presence of an electric arc furnace, they melt the scrap at a temperature of 2000 °C or 3.600 °F with small additions of coal or cast iron to provide with the carbon needed to produce the steel.