EVALUATING POTENTIAL FOR RECOVERY OF TE AS A BYPRODUCT OF AU EXTRACTION AT THE GOLDEN SUNLIGHT MINE (WHITEHALL, MT)

Tellurium (Te) is an energy-critical element, found in limited supply in the earth’s crust (average crustal abundance 3 μg kg^-1). The development of high efficiency CdTe-based thin-film photovoltaics has created unprecedented demand for Te, which is predicted to outstrip current global production. Although there are several high-grade Au-Ag telluride deposits in the Western US, almost all Te is produced as a byproduct of copper extraction. Telluride minerals of Au, Ag, Bi, and Pb, the most common Te-bearing phases in Au-Ag and Cu ores, vary widely in their vulnerability to extraction methods. Despite metallurgical challenges, recovering Te from Au-Ag mining is one potential way to meet increasing demand for Te. This project examined the behavior of Te throughout the Au extraction process at the Golden Sunlight Mine (Whitehall, MT). Total elemental analysis of mill samples was performed either by wavelength dispersive X-ray fluorescence (WD-XRF) or using peroxide sinter dissolution prior to analysis by inductively coupled plasma-mass spectrometry (ICP-MS). Elemental concentrations up to 100s mg kg^-1 were observed, indicating that significant amounts of Te are present in the mill samples. Future recovery of Te relies on a detailed understanding of Te speciation and transformation throughout the extraction process. However, this study is an important first step in determining the feasibility of Te recovery from Au-Ag telluride deposits.