Analytical methods for RE-Co alloys

Abstract

Total RE, Co and Fe in mischmetal and its cobalt alloys are determined by visual complexometric methods and instrumental X-ray fluorescence techniques. As Fe causes interference in the determinations of RE and Co and its own determination is affected by the presence of Co, it is removed by precipitation. The iron is determined from the precipitate and RE and Co from the filtrate. Accuracy of the method is checked by analysing synthetic mixtures of RE, Co and Fe. The individual REs in mischmetal are determined by X-ray fluorescence method. The analysis technique is based on comparison of the oxides of the test samples with standards (both in pressed pellet form) in the appropriate composition range. The total RE content of mischmetal determined through complexometric analysis is compared with the total RE determined through X-ray fluorescence.