(a) The ore is heated strongly in the absence of any blast of air
Calcination is a process in which an ore (Naturally found rock type) is transformed to oxide under high temperature.
The reactions during Calcination will not happen smoothly in the presence of air.
Calcium and carbon are converted to respective oxides, but not used in the process.
Limestone is used for the process of Iron Calcination.
Reactions that occur during Calcination are highly exothermic, hence they can be carried out in the absence of air.