The Preparation of Reference Materials for Germanium and Indium Ores

There are no ore standard materials which are characterized by the dispersed elements germanium and indium. In order to meet the need of geological exploration, Pb-Zn ores from Fankou of Guangdong were used as the candidates of Ge-ores and Pb-Zn ores from Tongkeng, Nandan of Guangxi were used as the candidates of In-ores. According to Class A standard material specifications, germanium ore (GBW07831) and indium ore (GBW07833) were prepared by ten laboratories using different analysis methods. Germanium ore standard contains certified values of 45 elements, whereas In-ore standard contains certified values of 47 elements. These elements include characteristic elements, coexisting elements, 15 rare earth elements, rock-forming elements and trace elements. The contents of Ge and In are 21.6×10^-6 and 39.7×10^-6, respectively in the germanium and indium ores. The two standard materials extend the types of ore standard material in China, which can be used as a chemical composition standard for Ge and In ores and used in daily quality control.