A blast furnace in operation at thyssenkrupp Steel's Schwelgern steel mill in Germany, turned 50 years old on 6 February.

Known officially as Schwelgern 1 – the Black Giant – the blast furnace is 110 metres in height and has a daily capacity of 10kt of pig iron; it is regarded as one of the biggest blast furnaces in the western world.

Back in February 1973, a team of over 50 chemists and designers worked towards the goal of a 'blue sky over Hamborn' – proving that even 50 years ago, the German steel giant was conscious of environmental protection. Since then, of course, there have been massive investments, claims thyssenkrupp Steel, in environmental protection measures, especially dust removal.

Today thyssenkrupp Steel claims it is well on the way to climate-neutral steel production. Coal-based pig iron production in the blast furnace is being replaced by direct reduction plants which can operate in a climate-friendly way using hydrogen. Eventually, the "black giant" will be retired.