| 摘要 |
<PICT:0850345/III/1> Chlorine and alkali metal hydroxide are produced from an alkali metal chloride brine by electrolysing the brine to free chlorine and the amalgam of the metal, decomposing the amalgam by reacting it with water in contact with an electrode negative to said amalgam to form negative-electrode-seeking ions and the alkali metal hydroxide, the ions being attracted to said negative electrode to produce electric potential, depolarising the negative electrode with a gas containing at least 18% by volume of oxygen, and employing the potential so produced to reduce the electrical potential required from an outside source to electrolyse additional brine. Sodium and potassium chlorides may be so electrolysed and the depolorising gas may be air or pure oxygen. As shown apparatus comprises a cell divided into two chambers 18, 19 by a partition 17 which does not extend to the bottom of the cell, and anode 23 and a hollow cathode 35 having a porous carbon surface 37 activated with silver. A circulating layer of mercury seals the aperture 45 at the bottom of the partition. In operation, an alkali chloride solution in chamber 18 is electrolysed, the alkali metal forms an amalgam with the mercury which then flows into chamber 19 containing water where it reacts to form the alkali metal hydroxide. Air or oxygen is supplied to the porous cathode through tube 41. Electrode 62 allows direct connection to be made to the mercury in order to start the cell. |
