Steel now requires a carbon source such as coal or carbon. That's it, no bells or whistles.

Features:

This mod adds an intermediate step to steel processing where you must grind iron ore with coal or carbon in order to make a steel mixture and then smelt it into actual steel.
This mod was designed for people who aren't using a big overhaul mod since those usually add their own steel complications.
A recipe to reuse already-smelted iron plates is also provided.

Compatibility:
Compatible with base game with or without space age.