AUS EINER IMPRAEGNIERTEN TRAEGERSUBTANZ BESTEHENDES MITTEL ZUR SORPTION VON FLUESSIGEN METALLEN UND VON METALLDAEMPFEN SOWIE VERFAHREN ZUR RUECKGEWINNUNG DER METALLE UND DER IMPRAEGNIERUNG

1376544 Sorption of mercury; reaction in silica gel ROTH HANDELS GmbH 12 June 1972 [10 June 1971 4 Aug 1971] 27434/72 Headings B1L and B1X [Also in Divisions Cl and C7] Absorbent for Hg liq. or vapour comprises SiO 2 gel impregnated with Ag NO 3 , the absorbent having an H 2 O content of 5-15% by wt. and being free-flowing and externally appearing dry. The absorbent may also contain a K 2 S or Ag 2 S. The absorbent preferably contains 5-50% by wt. of AgNO 3 and has a particle size of 0.2-0.5 mm. The absorbent may be prepared by mixing together the SiO 2 gel with an aq. soln. of the AgNO 3 until the mixture is free-flowing. The Hg may be recovered from the absorbent by firstly removing the Hg-Ag amalgain with ZnCl 2 and then dissolving the remaining Hg 2 (NO 3 ) 2 with HNO 3 and adding K, Ca, Al, Zn or Fe to the soln. to displace the Ag and Hg.