Solid-liquid phase equilibria of binary salt hydrate mixtures involving ammonium alum

The solid-liquid phase diagrams of binary mixtures of ammonium alum with ammonium iron(III) alum, with aluminum nitrate nonahydrate and with ammonium nitrate and of aluminum sulfate hexadecahydrate with aluminum nitrate nonahydrate are presented. The alum rich branches of the former three-phase diagrams were fitted by the Ott equation. The specific enthalpy of fusion/freezing of some compositions of the former three mixtures was determined by differential drop calorimetry.