A study on reduction kinetics of titaniferous magnetite ore using lean grade coal

• High titanium (23.23% TiO2) bearing magnetite ore has been exploited for reduction.
• Details of isothermal reduction kinetics have been studied.
• Mixed controlled mechanism initially contracting geometry followed by diffusion has been delineated.

Reduction behaviour of cold bonded self-reducing titaniferous magnetite ore (TMO) and lean grade coal briquettes have been investigated under isothermal condition. The reduction experiments of TMO-coal composite briquettes have been performed at varying temperatures ranging between 1273 and 1473 K for 3–60 min. The metallised briquettes are characterised by XRD and further FESEM. It can be inferred that the coal devolatisation and char gasification are solely responsible for the reduction process. The isothermal kinetic study has been performed considering the loss of oxygen fraction from the TMO which showed contracting geometry (CG3) to be the initial mechanism followed by diffusion controlled mechanism (Jander kinetic model; D4) in the later part of the reaction. The corresponding activation energies using Arrhenius Equation are evaluated as 93.42 and 179.80 KJ/mol, respectively.