Separation mechanism of iron and cobalt components from alloys using oxygen-chlorine arc plasmas

Abstract Arc plasma treatments of Fe-Co-Ni alloy using Ar, Ar-Cl 2 , Ar-N 2 , Ar-O 2 , Ar-Cl 2 -N 2 and Ar-Cl 2 -O 2 arc plasmas with varying O 2 flow rate were examined. Large amounts of fumes were formed when Ar-Cl 2 -N 2 and Ar-Cl 2 -O 2 plasmas were used. The Fe component was separated selectively from the alloy using Ar-Cl 2 , Ar-Cl 2 -N 2 and Ar-Cl 2 -O 2 plasmas with a small concentration of O 2 , while the Co component was separated using Ar-Cl 2 -O 2 plasmas with a high concentration of O 2 . The separation of Fe components was attributed to the selective chlorination of Fe. The separation of Co was attributed to both the chlorination of Co and the oxidation of Fe.