【国外标准】 Standard Test Method for Analysis of Ores, Minerals, and Rocks by the Fire Assay Preconcentration Optical Emission Spectroscopy (Withdrawn 2007)

1.1 This test method covers the spectrographic analysis of ores, minerals, and rocks for silver, palladium, platinum, gold and rhodium. The concentrations of precious metals which can be determined in the material being analyzed depend on the amount of sample assayed (Note 1). Concentration ranges for the lead fire assay beads are as follows:Element Concentration Range,%Silver 0.028 to 1.40Palladium 0.004 to 0.14Platinum 0.004 to 0.14Gold 0.003 to 0.14Rhodium 0.004 to 0.07Note 1—The amounts used are large enough to minimize weighing errors. A wide range of precious metal concentrations in rocks, minerals and ores can be covered by a modest range of percentages in the lead beads by regulating the weights of the initial sample and the lead bead. Also, both gold and silver can be determined in the lead bead. When either of these metals is used as a collector for the others in the assay, as is generally done, it cannot be determined without another assay.1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.Specific hazard statements are given in Section 9.