Dreistoffsysteme Wasser-Salz mit Lithiumselenat, Natriumselenat, Cobaltselenat und Magnesiumselenat bei 25°C

The phase interaction in the systems Li2SeO4-CoSeO4-H2O, Li2SeO4-MgSeO4-H2O, and Na2SeO4-CoSeO4-H2O at 25°C was studied. The systems Li2SeO4-CoSeO4-H2O and Li2SeO4-MgSeO4-H2O were found to be of the simple eutectic type. The pure salts Li2SeO4·H2O, CoSeO4·6H2O, Li2SeO4·H2O, and MgSeO4·6H2O were found to crystallize from these systems. The formation of a new phase, a double salt of composition Na2SeO4·CoSeO4·4H2O in the system Na2SeO4-CoSeO4-H2O was established. The composition of the double salt obtained was identified by physico-chemical and derivatograph analysis. X-ray-phase analysis of the double salt was carried out.