Question

Why carbon is used as reducing agent in commercial metallurgy?

Answer 1

Carbon is a good reducing agent, especially at higher temperatures, because it is a non-metal and it combines with oxygen and forms its gaseous non-metallic oxides. 

Answer 2

Reducing agents are required for redox chemical reactions to occur. Reducing agents donate electrons in order to reduce another substance. Reducing agents make it possible to power electronic devices and are also involved in corrosive chemical reactions, such as rust formation.