| 摘要 |
<p>1515610 Selenium and mercury PREUSSAG AG-METALL 22 Oct 1976 [23 Dec 1975] 43994/76 Heading C1A [Also in Division C7] Selenium and mercury are recovered from intermediate-products, by-products or waste products obtained from a metallurgical process, the products being suspended in water or dilute hydrochloric acid, chlorine gas is introduced into the aqueous suspension until mercury combined with selenium and/or sulphur, and elementary selenium, which are initially in the suspension, have gone into solution, the solution is alkalized to precipitate the mercury as mercuric oxide, and, after filtration to remove the mercuric oxide and acidification, the selenium is precipitated from the filtrate by reduction. The solution into which the chlorine gas has been introduced may be boiled to reduce the selenium. Residual mercury in the solution after alkalization may be precipitated by adding ammonium hydroxide solution.</p> |
