Depuration from SiF4 of industrial gaseous waste

The problem of wet treatment of gases containing fluorine compounds produced in industrial processes, with particular reference to the phosphatic fertilizers and ceramic industries, is here considered.With this purpose and also in view of the low limits imposed by law, the chemical-physical properties of the SiF₄ and HF absorption in H₂SiF₆ solutions are discussed. In connection with these properties and with fluorine content in the gases to be treated , several devices and plant schemes are examined, also considering the problem to dispose of liquids at high Fluorine concentration for its recoveryThe results obtained in some industrial plants are finally presented and discussed.