| 摘要 |
PROBLEM TO BE SOLVED: To elute Sb from a chelating resin with a low consumption of alkali at low cost by repeatedly eluting with a part of the supernatant or filtrate neutralized with alkali and then eluting with an acid soln. having the Sb concn. below a specified value and acid concn. above specified value. SOLUTION: The neutralized soln. is repeatedly used in the initial stage, because the free acid concn. is lowered preferably to <=2 N and the consumption of Ca(OH)2 , etc., for neutralization is reduced. Meanwhile, normal elution using only an acid soln. is applied in the subsequent stage. Consequently, the Sb concn. is controlled to <=3 g/l and the acid concn. is controlled to >=4 N to keep the elution rate high. The acid concn. of the soln. lowered in Sb concn. in the latter stage is regulated, and the soln. is repeatedly used in the subsequently stage as an eluent. The eluent normally contains 10-300 g/l HCl and 1-3 g/l Sb. |
