Multiple choice

For what purpose is limestone used in the extraction of iron from haematite?

  1. As gangue

  2. As slag

  3. As reducing agent

  4. As flux

  5. -

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The limestone is added to convert rocky material into slag which melts and runs to the bottom. The heat of the furnace decomposes the limestone to give calcium oxide. Thus, it is used as a flux.