| abstract |
<PICT:0832196/III/1> A denuder 28 for producing sodium hydroxide employs a sodium amalgam anode 36 delivered from an electrolytic cell 25 (see Group XXXVI) and cathodes 29 formed wholly or mainly of heavy metals of the first and/or eighth group of the periodic system, Ag, Cu, Co, Ni being specifically mentioned. The metals may be in the form of coatings and may be alloyed, e.g. with minor amounts of other metals, An oxygen-containing gas, e.g. air, is delivered to the cathodes 29 at 38, and water is introduced at 33. In the apparatus, ten electrolytic cells supply amalgam to nine denuders, the mercury leaving the denuders being distributed to the ten cells. The cathodes may be meshes, boxes, sintered structures or hollow plates. |