| 摘要 |
Decontamination of solids (I) contaminated with Hg comprises : (a) mechanical prepn.; (b) vaporisation of Hg by dry distn. at 200-400 deg.C in an inert atmos., esp. a N2 stream; (c) deposition of Hg as HgS from the gas stream in an aq. alkali polysulphide-sulphane soln. (II); and (d) sepn. of HgS from (II).Pref. (a) (I) is crushed and pressed if necessary to reduce its water content; (b) Hg is vaporised below 400, usually below 300 deg.C, with a dwell of 30-60 min; (c) (II) is circulated; and (d) HgS is sepd. by filtration, centrifugation or esp. sedimentation. Stage (b) is carried out in an indirectly heated rotary drum furnace. Stage (c) uses condenser(s).
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