Projektinitiativ #74: Fundamental studies of how to improve the slag-line refractories ( 1 kommentar)

Fundamental studies of how to improve the slag-line refractories to improve the conditions to both produce clean steel and a slag that can be turned in to a commercial product. It is a well known phenomenon that the refractory erosion is high especially at the slag/steel interface during secondary refining. This is due to strong chemical reactions between the salg and the refractory including the binder materials. Typically, carbon-based binders are used in the industry. However, these are not stable always. For example, carbon in the refractory can react with the refractory material such as MgO as the pressure is lowered during vacuum treatment. The carbon content can also be lowered during the preheating of the ladles before tapping.

It is also known that we traditionally optimize the process with respect to the steel. However, in the future it will be equally important to optimize a process so that we produce a slag that can be transformed into a commercial product. Thus, this aspect will be an important part of this proposal.

The approach in this study is to take a fundamental approach to study how the refractory materials and binders can be improved with respect to stability towards refractory erosions. Here, an essential part of the research is to consider the slag compositions so that they will both be optimized respect to a lower refractory wear as well as a potential to make new products. The type of refractories to be studied will be discussed together with the participating companies. The project will study the following aspects for the selected refractory materials:
a) alternative binder materials to use instead of carbon
B) use of coated refractories at the slag line
C) how to modify the slags to enable a better recyclability as well as a dercreased refractory wear

The fundamental research will include the following aspects and for the selected refractories and slags
i) dissolution kinetics in lab scale experiments
ii) wettabilities between the refractories and slag as well as steel in lab scale experiments
iii) thermodynamics

Pär Jönsson, Björn Glaser and Andrey Karasev – Division of Processes, KTH Materialvetenskap

Namn Pär Jönsson
Organisation KTH Materialvetenskap

Kommentar #1

In order to produce "the steels of the future" it is very important to control the amount and type of inclusions. When slag also become a "procuct" we also have to control its composition even more than today. Therefore the goal must be to minimize the interaction with all refractories, and especially from the slag lining which is more exposed during the process.

Namn Ewa Sjöqvist Persson
Organisation Uddeholms AB