Iron and steel slag in road building: Routine determination of the total fluorine content
Using iron and steel slag in road building can cause the fluorine compounds contained in the slag to enter the environment. Dominik Hahn, currently a PhD student in the Technical Chemistry department at the University of Koblenz- Landau, developed a method for the determination of fluorine content in slag using Combustion IC as part of his bachelor's thesis. For this, he was awarded the VDI research prize by Verein Deutscher Ingenieure Mittelrhein e. V. (the Association of German Engineers for the Middle Rhine region).
Slag: A useful byproduct
In 2016, approx. 460-600 million tonnes of iron and steel slag (blast furnace and steel mill slag) accrued in the steel industry, according to an estimate by the United States Geological Survey. Slag is the non-metallic substance that is left over when ore is smelted. However, it is not a waste product: For example, slag is a basis for alternative construction materials in road engineering or for raw materials in the cement industry.
An important parameter for assessing the environmental compatibility of iron and steel slag is the leachability of fluorine. How the leaching behaviour of slag products containing fluorine works is not entirely clear. Current research projects are therefore focusing on understanding the complex processes of fluorine leaching and influencing these by making changes in metallurgical work.