Analysis of Sulfides for Gold and Associated Trace Metals by Direct Neutron Activation With a Low-Flux Reactor

A routine method for the direct determination of Au and associated trace metals in sulfides has been developed for use with a low-flux nuclear reactor (SLOWPOKE II Reactor Facility, University of Toronto). Small samples (100–200 mg) are analysed simultaneously for Au, Ag, As, Sb, Mo, Co, Se, Cd, Fe, and Zn. Sulfides containing finely divided gold can be analysed with a high degree of precision and yield results which agree closely with commercial fire assay-atomic absorption analyses for Au. Favourable comparisons with other analytical techniques (flameless atomic absorption and emission spectrometry) are also indicated for Ag, As, and Sb. Neutron activation has the advantage of providing precise and accurate results for these elements without chemical separation or preconcentration. Analyses of 10 sulfide-bearing reference materials from CANMET, Ottawa are compared with published best values for selected trace metals including Au.