This study represents a part of comprehensive research aimed at integrating nickel into a
thermodynamic database constantly developed at Pyrosearch. The behaviour of Ni in calcium-ferrite
slags is considered. An integrated approach combining experimental and thermodynamic modelling
methods has been employed to predict phase equilibria in the NiO-CaO-FeO-Fe2O3 system under
oxidising conditions and in equilibrium with the metal FeNi phase.
The compositions of liquid slags and coexisting solid solutions have been determined through the
analysis of equilibrated and quenched samples by electron probe microanalysis technique (EPMA).
The research results are presented in the form of liquidus projections on the corresponding phase
diagrams, considering both oxidising and reducing conditions. The solubility of Ni in spinel, dicalcium
ferrite and calcium oxide as well as solubility of Fe and Ca in Ni monoxide, have been examined
under several atmospheric conditions. Additionally, the compositions of the NiO-FeO monoxide in
equilibrium with metal phase have been studied. The experimental data not only support the
outcomes of thermodynamic modelling but also validate the parameters of the applied
thermodynamic models, thus confirming the reliability and accuracy of the integrated approach.