| 摘要 |
<p>1330197 Mercury cathode cell FRIEDRICH UHDE GmbH 19 Nov 1971 [21 Nov 1970] 53842/71 Heading C7B [Also in Division B1] Mercury-bearing wastewater, from a plant for the electrolysis of brine employing a mercury cathode, is purified by evaporating water from the wastewater at subatmospheric pressure (e.g. 92À5 mm Hg) and condensing the vapour, the condensate being used as flushing water for the electrolysis plant. The concentrated impurities are intermittently discharged from the evaporator, by means of an adjustable timer, and may be treated to obtain mercury-bearing sludge, the dry sludge being sent to a distillation oven where mercury is recovered. Before being introduced into the evaporator, the wastewater may be submitted to treatment with hydrazine followed by filtration. The heat needed for the distillation may be obtained from hot brine.</p> |
