What is the slag formed in the extraction of iron?

1. $\mathrm{CaO}$
2. $\mathrm{CaSiO}_3$
3. $\mathrm{MgSiO}_3$
4. $\mathrm{SiO}_2$

Asked in: AP EAMCET 2018 (23 Apr Shift 2)

Practice more General Principles and Processes of Isolation of Metals questions on Aicharya