ArcelorMittal Ostrava's slag recycling project reaps many rewards

2017-10-19

Oct. 18, 2017 - The Czech Republic's Ministry of Industry and Trade has recently announced the results of its "Transforming waste into resources" competition. Jitka Halamová attended the award presentation at the Czech Senate in Prague on behalf of ArcelorMittal Ostrava.

Her project, which substituted the primary raw materials for steelmaking with specially processed recycled slag, ranked fourth in the competition of 127 contestants. 

A panel of experts from the Ministry of Industry and Trade, the Ministry of Education, universities, professional associations and unions assessed the entries.

In accepting the award, Jitka Halamová whose job in the technical excellence team is to efficiently recycle waste back into the production process, said, “This award is an affirmation of a project I have been working on for more than two years.” 

Steel production generates slag pellets as a by-product. While slag is a valuable source of iron, its phosphorus content limits its usefulness in the sintering process, because phosphorus reduces the quality of the resulting pig iron.

So traditionally, very little slag was returned to the sintering process. 

But by mechanically processing the 0-8mm steel slag which contains 35-40% of iron, ArcelorMittal Ostrava has been able to increase the slag’s iron content to 54-57%, while keeping the phosphorus content low enough to reuse the enriched slag in the sintering process, replacing iron ore, additives and fuel in production.

One tonne of enriched slag replaces:

    1.027 tonnes of ore

    336kg of carbonate additives

    Fuel

Using slag in this way increases the sustainability of the business’ operations, but also saves it money compared to extracting and using primary natural resources. In 2016 ArcelorMittal Ostrava recycled on average 1,900 tonnes of enriched slag per month and in the process saved a total of over $865,000 US. 

“Since we've been using a special technology to sort the slag to end up a with higher iron content and a lower level of phosphorus, we have been able to reuse that slag in our operations in much higher amounts than before. Thanks to that, we are able to save iron ore, additives and fuel and, at the same time, we don’t accumulate large amounts of waste on our premises,” says Jitka Halamová.