La determination des EGP dans les roches: revue des techniques analytiques basees sur Putilisation de la fusion plombeuse et de la fusion au sulfure de nickel

CIM Bulletin, Vol. 83, No. 936, 1990

Mario Bergeron, INRS-Georessources, Ste-Foy, Quebec

Mineral exploration for PGE (PGE: platinum, palladium, iridium, osmium, ruthenium, rhodium) requires appropriate measurement methods. Selecting an appropriate analytical method must take into account several factors. The most important ones are: the type of material to be analyzed, its representativity, the required detection limits and the operational cost. Several analytical approaches are possible, all of which require a preconcentration step. One of the most appropriate methods consists of carrying out a lead fire-assay followed by ICP-ES measurements (15 $/sample). In cases where one or more of the PGE are present in interesting concentrations, a preconcentration by nickel sulphide fire-assay followed by neutron activation provides concentration for all PGE as well as gold measurements (90 $/sample). It must be stressed that nickel, if present at concentrations higher than 4%, interferes during the preconcentration step by lead fire-assay, which causes platinum concentration to be underestimated. Therefore, PGE exploration program in nickel-rich rocks should utilize a nickel sulphide fire-assay instead of a lead fire-assay.
Mots Clés: Exploration, Platinum group elements, Lead fire-assay, Nickel sulphide fire-assay.