Crystallization of ammonium aluminium alum

The report deals with the research and development of the process for production of extra pure ammonium aluminium sulphate by crystallization from solution. The distribution of contaminants (Na, K, Fe, Si, Ca, Cr, Mg, Ti, Ga, Mn, Zn, Co, Pb a Cu) between the crystalline phase and solution was determined for two initial concentrations of ammonium aluminium sulphate and for two final crystallization temperatures. The effect of recrystallization of ammonium aluminium sulphate and the effect of the excess of ammonium ions upon the product purity was investigated