METHOD FOR PREPARING NITROGEN TRIFLUORIDE NF3 BY ELECTROLYSIS AND INSTALLATION THEREFOR

摘要

The invention concerns a method for preparing nitrogen trifluoride by electrolysis comprising NH4F and hydrofluoric acid HF (NH2F, xHF) with at least a carbon anode of such quality as to prevent passivation and disintegration thereof or a nickel anode, wherein, when the anode is made of carbon: the electrolytic solution NH4F, xHF is such that x ranges between 0.95 and 1.45, that is 34 to 44 % of free HF mass; the temperature of the solution ranging between 115 and 140 DEG C ; the current density being 5 to 15 A/dm<2>; the electrolysis voltage being 5.8 to 9.0 volts ; and when the anode is made of nickel: the electrolytic solution NH4F, xHF is such that x ranges between 1.4 and 1.6, that is 43 to 46 % of free HF mass; the temperature of the solution between 105 and 125 DEG C; the current density is between 6 and 12 A/dm<2>; the electrolysis voltage between 5.5 and 8.5 volts.