[Solved] Given below are the processes used in the metallurgy of Alum
Detailed Solution. Bayer's process when the impurity of ferric oxide is present. Serpeck's process when the impurity of silica is present. Hall's process when the impurity of silica and ferric oxide both are present. Hoopes process it is not used to produce pure alumina from bauxite. It is used for purification of Aluminium.