A process for the recuperation of mercury from an inactive mercury - ii - chloride / activated carbon - contact

摘要

1,162,328. Recovery of mercury chlorides from catalysts. KNAPSACK A.G. 2 April, 1968 [4 April, 1967], No. 15742/68. Heading C1A. [Also in Division C7] In the recovery of Hg from a contaminated inactive HgCl 2 / active C catalyst by burning the C with a deficiency of O 2 or air so as to produce predominantly CO, a mixture consisting of gaseous Hg, HgCl 2 and Hg 2 Cl 2 is expelled or sublimed off (together with combustion gases), the mixture is condensed, and the HgCl 2 and Hg 2 Cl 2 in the condensate are reduced to Hg by addition of a reducing agent such as hydrazine sulphate, ferrous sulphate or formaldehyde. As shown, inactive catalyst 9 is burnt in shaft furnace 3. The products leave the furnace through line 10 and are cooled in tube condenser 11. Condensate and combustion gases pass through line 13 to scrubbing tower 14 which is supplied with reducing solution 15. Hg is withdrawn at 17, while combustion gases, after scrubbing out of mercury chloride contaminants and reduction thereof, leave through line 16 and are burnt. The reducing solution is recycled by pump 19 through line 18, fresh solution being introduced when necessary through line 21.