Ion Exchange Separations and Atomic Absorption Determination of Trace Metals in Ores after Basic Fusion

Abstract

The determination of trace constituents in ores by atomic absorption after basic fusion and solution in strong acid is erratic due to the light scattering and aspirator clogging of the high concentration of sodium salts. The sodium is separated from the trace constituents using a column procedure and an iminodiacetate chelating ion exchange resin which will retain di- and trivalent metal ions at pH values above 6.0 but will not retain alkali metal ions. The trace constituents are determined by atomic absorption after elution with HCl. The precision (standard deviation of the mean) of the atomic absorption method is increased at least fivefold by the resin separation and the method is applicable to concentrations in the low ppm range. The standard deviation of the mean for an NBS sample containing 0.007% Cu is 0.0004%.