Fluorine Production

Elemental fluorine is prepared industrially by Moissan's original process: electrolysis of fusion KFx(1.8-2.0)HF, which is enriched by HF up to 40-41%. Hydrofluoric acid, which is the main source of fluorine, may be obtained from the reaction between sulphuric acid H₂SO₄ and calcium fluorite CaF₂, or by apatite and phosphorites processing. The electrolytic furnace is made from steel, electrodes: carbon anode and steel cathode. Electrolysis is processed by 95-100°C with voltage 9-11 V. The fluorine power yield may reach 90-95%. Produced fluorine may contain up to 5% of hydrofluoric acid HF which is removed by freezing and absorbing by sodium fluoride. Fluorine is stored either in gaseous state under pressure or as liquid, cooled by liquid nitrogen in special equipment made of nickel and its alloys (Monel) with copper, aluminium and its alloys, stainless steel or brass.