Primary steel making process is conventional process, it mainly constitute Blast Furnace -> LD/BOF route. Whereas secondary steel making processes are hybrid processes, they have a number of routes such as :

1. Scrap -> EAF

2.DRI -> EAF

3. DRI -> Induction furnace

4. BF + DRI -> EAF

and counting

Major bulk steel making processes like Open hearth, LD & EAF are termed as primary steel making, where melting & major portion of total refining  is carried out.

Secondary steel making includes processes where final refining and finishing of steel takes place for example Ladle furnace, AOD, VOD etc.