Abstract:
BACKGROUND Carlin-type gold deposits have attracted much attention because of the influence of As on the analysis and recovery of gold. It is necessary to develop the specific reference materials (RM) to support application research.
OBJECTIVE Study samples were collected from the super large Carlin-type gold deposit in the Yangshan gold mine, discovered in recent years. Four kinds of reference materials GBW07854-GBW07857 for Carlin-type gold ore were developed according to country-level standard technical specification.
METHODS A total of 20 laboratories simultaneously determined element values. The main gold analysis methods included Atomic Absorption Spectrometry and Fire Assay. Wet analysis uses gradient roasting-activated carbon adsorption of gold to separate arsenic and other interference components. Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) and Spectrophotometry were mainly used to analyze arsenic. Citation analysis relative deviation permissible limit to define within-group outliers makes up for the incompleteness of the Dixon and Grubbs methods to eliminate outliers.
RESULTS The homogeneity test index F < F0.05(29, 30)=1.84, indicated that there were no significant differences between the groups and within the group. No statistically significant changes were observed in 5 analyses during 22 months. The certified values of gold and arsenic in this series of certified reference materials (CRMs) were superior to those of the same level country-level gold ore RM and foreign arsenic-bearing polymetallic ore RM.
CONCLUSIONS This series of CRMs can be used as standards for the analysis and study of gold and arsenic in Carlin-type gold deposits.