Aluminium is extracted from alumina (Al2O3) by electrolysis of a molten mixture of
-
Al2O3 +HF +NaAlF4
-
Al2O3 + CaF2 +NaAlF4
-
Al2O3 +Na3AlF6 +CaF2
-
Al2O3 +KF +Na3AlF6
C.
Al2O3 +Na3AlF6 +CaF2
Alumina, Al2O3, is a bad conductor of electricity and has a very high melting point, so before subjecting to electrolysis, it is mixed with fluorspar (CaF2) and cryolite (Na3AlF6), which lower its melting point and make it more conducting.