Stability of Inorganic Fluorine‐Bearing Compounds: I, Binary Metallic Fluorides

Because of the practical importance in connection with the loss of fluorine from slags and enamels, the stabilities of NaF, KF, MgF 2 , CaF 2 , and ZnF 2 in dry and moist atmospheres at elevated temperatures were studied by following the loss in weight of 0.25‐ to 2.0‐gm. samples. The principal reaction was shown to be hydrolysis of the salts in moist atmospheres. The activation energies for the hydrolysis were calculated. NaF and KF were hydrolyzed little or not at all below 1000°C., MgF 2 was hydrolyzed readily in the range 1050° to 1150°C., CaF 2 was hydrolyzed slowly in the range 1200° to 1350°C., and ZnF 2 was completely hydrolyzed in the range 680° to 750°C.