| 摘要 |
<p>1458103 Treating mercury containing wastes CHEM-TROL POLLUTION SERVICES Inc 21 Jan 1974 [19 Jan 1973] 02734/74 Heading C1A Wastes containing mercuric compounds, e.g. mercury muds from electrolytic processes, are treated with at least an equal amount by weight of spent pickle liquor containing sulphuric acid to convert mercury compounds into basic mercuric sulphate and then with a lime slurry to neutralize the mixture and obtain a solid mass containing insoluble mercuric carbonate and a liquid portion containing less than 10 p.p.b. soluble mercury. When the waste contains metallic mercury it is first treated with H 2 SO 4 e.g. a form of spent pickle liquor in the presence of an oxidizing agent to form mercuric compounds which are then treated as above. The solid mass may be used as a land fill material without risk of mercury being leached out under alkaline conditions. In one embodiment the mercury mud is first treated with dilute sulphuric acid, e.g. in the form of a pickle liquor, to convert calcium carbonate present to calcium sulphate and cause any finely divided mercury to be oxidized to mercuric chloride or mercuric oxide. The ratio of pickle liquor to treated waste preferably ranges from 1 to 20 : 1 by weight, especially 10 to 1. The lime slurry suitably contains 5 to 28% by weight CaO and is used to neutralize the mixture to pH 7À5.</p> |
