| 摘要 |
<p>PROBLEM TO BE SOLVED: To regenerate a waste iron chloride liq. etchant contg. nickel by adding gaseous chlorine to the waste etchant to oxidize the contained iron, heating the waste etchant under reduced pressure to concentrate it to a specified so.gr. and then cooling the waste to crystallize nickel chloride. SOLUTION: Gaseous chlorine is blown into a waste iron chloride liq. etchant contg. >=40% FeCl3 , several % FeCl2 and about 5% NI to oxidize the iron (II) in the waste to iron (III). The waste etchant is heated at 80-100 deg.C and 0.2-1.0kg/cm<2> pressure to concentrate it to 1.6sp.gr. The concd. waste etchant is cooled to <=50 deg.C and kept at that temp. to complete the crystallization of nickel chloride. The crystal is separated by filtration, the free hydrochloric acid and iron (III) chloride concns. in the filtrate are adjusted, then the filtrate is reutilized as a liq. etchant, and the filter cake is used as Ni resources.</p> |
