A literature study on measurement methods for calculating the FeO activity in slag

Sammanfattning: During the time we live in, climate change is more important than ever. HYBRIT, formed bySSAB, LKAB, and Vattenfall, is an initiative set out to make the steel production fossil free, by developing a novel process that produce direct reduced iron (DRI) using hydrogen as reagent. Electric arc furnaces (EAF) will then be employed to melt the DRI. For SSAB, it is important to obtain a satisfied dephosphorisation in the EAFs for the production of high strength steel. The composition of the DRI, has a big impact on the dephosphorisation and it is important that the slag has an optimal basicity and FeO content. To better understand the impact that FeO has on dephosphorisation, experimental data has to be collected and the FeO activity calculated in different slag systems. Activity measurements of FeO is rather complex. In this thesis, three methods were looked at: experimental determination, electrochemical methods and equilibrating the slag. Equilibrating the slag turned out to be the best suitable method forcalculating the FeO activity and is recommended to be evaluated further.