| 摘要 |
<PICT:1075525/C6-C7/1> Sulphur hexafluoride is made by electrolyzing hydrogen sulphide in anhydrous H.F., applying 7-20V and preferably 7-8V. Current density of at least 0.023A cm2 is used, a nickel anode and an iron cathode spaced 2 to 5 mm. H2S is admitted to the H.F. in a finely divided stream and at the rate of 0.094 to 0.1 g per ampere hour. An electrolytic cell 1 has a number of anodes and cathodes arranged alternately and is cooled by brine. Hydrogen sulphide stored in a receiver 14 from a supply cylinder 13, passes in controlled amount governed by pressure into the cell containing H.F. and KF. A reflux condenser retains H.F. in the cell, and the electrolytic product passes through a safety vessel 3 and frit 5 in water washing plant, two lye washers 7 and a sodium sulphite washer 8, where oxygen difluoride and other by-products are removed. The treated gases are then dried by KOH tower 9 and CaCl2 tower 10. Sulphur hexafluoride is condensed at a tower 11 cooled by liquid hydrogen. Electrolytically produced hydrogen escapes through a meter 12. |
