| 摘要 |
<p>PURPOSE:To effectively extract and remove Fe ions from a galvanizing bath by contact with an extracting reagent by using a specified acidic extracting reagent and a specified basic extracting reagent as the extracting reagent. CONSTITUTION:A galvanizing bath 1 of <3 pH contg. Fe ions as impurities is introduced into an extracting apparatus 3 provided with a porous solid membrane 2 of polytetrafluoroethylene or the like and the bath 1 is brought into contact with an extracting reagent with the membrane 2 in-between to extract into an extracting agent 11 and remove the Fe ions. At this time, a soln. prepd. by diluting an acidic extracting reagent such as 2-ethylhexyl phosphonate and a basic extracting reagent such as 1-(3-ethylpentyl)-4- ethyloctylamine or other primary to quat. amine in 0.1:1-1:1 molar ratio with CCl4, heptane or the like is used as the extracting reagent. The Fe ions in the extracting reagent, after passing through an alkali is washing tower 5, are sent to a back-extracting apparatus 4, where the Fe ions are extracted and removed with a reducing agent such as sodium dithionite as a back- extracting reagent.</p> |
