Which process is used to convert sulphide ores into oxides by heating them in the presence of excess air?

In the $Hall-Heroult$ process,which substances are added to alumina to lower its melting point?

Which metal is purified by the method of liquation?

Which of the following metals exist in their native state in nature?
$(i)$ $Cu$
$(ii)$ $Au$
$(iii)$ $Zn$
$(iv)$ $Ag$

What is the molecular formula of calcium silicate (slag)?

In the electrolytic refining of metals, the insoluble impurities present in the impure metal settle down at the bottom of the container below the anode. What is this called?