| 摘要 |
1,247,563. Mercury chloro-alkali or diaphragm chlorate cells. HOOKER CHEMICAL CORP. Nov. 22, 1968 [Dec. 4, 1967], No. 55493/68. Heading C7B. Hypochlorite is removed from the cell liquor of a mercury chloro-alkali or disphragm chlorate cell by contacting it externally of the cell with an ethylenically unsaturated compound to produce chlorohydrin, or, by further reaction with caustic alkali, a glycol and/or polyol, and recycling the treated liquor. For a diaphragm chlorate cell, the treated liquor may be passed to crystallizer from which the mother liquor containing the product of reaction, e.g. ethylene glycol, and make-up feed brine is recycled to the anode compartment of the cell, the product being sacrificially oxidized at a graphite anode in preference to carbon so reducing its oxidation. Similarly, depleted mercury cell brine, containing the product after reaction with the ethylenically unsaturated hydrocarbon, may be reconstituted preferably after dechlorination and neutralizing with alkali metal (e.g. sodium) chloride and recycled to the mercury cell where the product serves to decrease graphite anode oxidation and reduce the amount of hydrogen evolved with chlorine in the cell. The unsaturated compound is preferably an aliphatic or a cycloaliphatic hydrocarbon of C 2-8 , e.g. ethylene, propylene, 2- methyl-propene, 1- or 2-butene, 1, 3-butadiene or pentadiene and/or 1, 4-pentadiene. |
