| 摘要 |
A water-soluble barium compound is prepared from an aqueous solution of barium sulphide by a process comprising contacting a strongly acidic cation exchange resin in its sodium or potassium form with an amount of the barium sulphide solution such that some barium sulphide remains unchanged, separating the resin from the resulting solution, which contains barium sulphide and sodium or potassium sulphide, and thereafter regenerating the resin with an aqueous solution of a sodium or potassium compound whose anion corresponds to that of the barium compound desired, separating the resin from the resulting solution and isolating the desired barium from that solution. The elution with a sodium or potassium compound is preferably effected with the hydroxide, yielding barium hydroxide which may be crystallized out from the eluent which also contains alkali metal hydroxide, or with the chloride yielding barium chloride which may be recovered by crystallization or salting out. Sodium and potassium acetates and nitrates may be used analogously. The process may be operated cyclically. The barium sulphide solution is preferably passed through the exchange resin until barium sulphide appears in the issuing effluent containing sodium or potassium sulphide. The latter can be recovered from this effluent by precipitating the barium using alkali metal carbonate or by feeding the effluent to one or more exchange columns operated as above and then if desired treating it in accordance with the parent invention to obtain substantially pure alkali metal sulphide.ALSO:Barium acetate is prepared from an aqueous solution of barium sulphide by contacting a strongly acidic cation exchange resin in its sodium or potassium form with an amount of the barium sulphide solution such that some barium sulphide remains unchanged, separating the resin from the resultant solution, thereafter regenerating the resin with an aqueous solution of sodium or potassium acetate and isolating the desired barium acetate from the resultant effluent. |
