Generation of magnesium for in situ desulphurisation–investigations on influence of inert gas flowrate

In situ generation of magnesium by the reduction of its oxide is being considered by researchers as a possible means of effective desulphurisation of liquid iron. Generation of magnesium in this process will be affected by the flow rate of inert gas. The influence of the flow rate of inert gas on the degree of reduction of magnesium oxide by aluminium was studied. The liberation of magnesium increases with increase in flowrate of inert gas. A mathematical model was developed to predict the influence of argon flow rate on the degree of reduction. The reduction was significantly influenced by temperature. Whereas the degree of reduction was about 30% at 1473 K, it was about 85% at 1673 K. SEM studies showed that the reduction of the oxide with aluminium was a complex process. A part of magnesium vapour generated during reduction was trapped inside the (oxide+aluminium) tablets. Temperature, flowrate of argon, and the porosity of the tablets were parameters that critically influenced the degree of reduction.