| 摘要 |
<p>1403638 Removal of mercury from gases SHOWA DENKO KK 3 Dec 1973 [4 Dec 1972] 55849/73 Heading C1A Mercury is removed from a contaminated gas by its passage over activated carbon impregnated with sulphuric acid. The adsorption may be carried out under conditions represented by where t=adsorption temperature (‹ C.), P= partial pressure of water in the gas to be treated (mm. Hg.), and A and B are numerical factors of 3À34Î10<SP>-3</SP> and 3À7Î10<SP>-4</SP>, respectively. The amount of sulphuric acid contained in the activated carbon is preferably more than 10% by weight based on the activated carbon. The activated carbon may be prepared by immersing it in aqueous sulphuric acid (30-80% by weight) and drying it at 100-200‹ C. in an air stream. The method may be used for purifying gas streams of air, hydrogen, nitrogen or carbon dioxide (especially also containing sulphur dioxide or halogens as impurities) as for example, gaseous discharges from a mercury mine, non-ferrous metal smelting plant or a coal-fired boiler. The mercury may be recovered by heating the spent activated carbon at over 200‹ C. in a stream of super-heated steam and condensing out the mercury.</p> |
