Also in the case two–components mixtures, calcium carbonate or oxide with iron (III) oxide, in which ferrite are formed, and three components mix: CaO + Al 2 O 3 + Fe 2 O 3, in which alumina–ferrites are formed, Jander's formula is well satisfied.. First aluminate formed in the mixture CaO + Al 2 O 3 is the monocalcium aluminate CaO·Al 2 …