THE SYSTEMS Li 2 SO 4 –K 2 SO 4 –H 2 O AND Li 2 SO 4 –Na 2 SO 4 –H 2 O AT 25 °C.

Abstract

The 25° isotherm of the system Li 2 SO 4 –K 2 SO 4 –H 2 O shows the existence of the double salt, Li 2 SO 4 . K 2 SO 4 , whereas that of the system Li 2 SO 4 –Na 2 SO 4 –H 2 O yields no double salt but extensive solid solution of lithium sulphate in sodium sulphate. On the other hand, a study at 39.5 °C. of the latter system shows that the double salt, Li 2 SO 4 . Na 2 SO 4 , does form at this temperature, accompanied as before by solid solution of lithium sulphate in sodium sulphate. The transition temperature for the reaction[Formula: see text]is 29.3 °C. A further transition, of unknown nature, occurs between 49° and 57°.