Abstract
For the purpose of determining comparatively small contents of Zn in nodular cast iron treated with Zn-alloy, the authors studied on the separation of Zn from cast iron by applying the oxine volumetric method. The procedure obtained was as follows: -
1. Sample was dissolved in HCl+HNO3, baked, and then dissolved again by adding HCl Si, graphite, etc., were separated by filtration.
2. The greater part of iron were removed by applying the ether extraction method.
3. The Cu was separated from the extractive acid layer solution by introducing H2S gas into it and the remaining Fe and Mn were precipitated by adding NH4Cl+NH4OH and (NH4)2S2O8 reagent, and they were removed by filtration.
4. If Ni was contained in sample, it was precipitated by dimethyl-glyoxime reagent, and was removed by filtration.
5. The filtrate was prepared so as to be of slightly acetic acid solution, and Zn was precipitated by addition of oxine reagent, and dissolved wih HCl, and were titrated by N/25 KBrO3 sol. and N/25 Na2S2O3 sol.
By this method, reproducible results were obtained.
