| 摘要 |
1,138,667. Removal of mercury from caustic soda solutions. CANADIAN INDUSTRIES Ltd. 6 April, 1967 [22 April, 1966], No. 15805/67. Heading C1A. [Also in Division B1] Mercury is removed from aqueous caustic soda solutions by passage through a bed comprised of a particulate material consisting of polyethylene shreds, polytetrafluoroethylene shreds, graphite, charcoal or activated carbon, and a metal e.g. nickel, stainless steel, or tantalum wettable by mercury but resistant to attack by caustic soda, the metal being in the form of discrete particles mixed with said particulate material or in the form of separate liquid-permeable layers. Caustic soda liquor from a mercury cell process for the production of caustic soda and chlorine is passed from feed line 9 into the column 1 which contains two layers 11 and 12 of nickel turnings, or of nickel wire mesh, and a layer 13 of activated carbon. Clarified aqueous caustic soda, freed of the brownish cast caused by organic contamination of the feed water to the cell, flows out of the column via line 3; mercury may be recovered from the bed by backwashing with water. |
