TELLURIUM SPECIATION IN SURFICIAL WEATHERING ENVIRONMENTS

Basic tellurium (Te) geochemical behavior is largely unexplored due to low crustal abundance, but increasing industrial use creates a need for information on Te behavior in the environment. Telluride-bearing ore minerals frequently remain in mill tailings after extraction and extended weathering periods often give rise to stratified geochemical environments in the near surface. Characterization of particles in these environments using a suite of geochemical tools such as X-ray diffraction, particle size analysis, micro-focused X-ray fluorescence, and X-ray absorption spectroscopy provides insight into the effects of the geochemical environment on mineral weathering and Te speciation. Our characterization of paired ore samples and mill tailings sampled as a function of depth demonstrate marked Te oxidation. Tellurium concentrations are often elevated in areas enriched in clay-sized fractions, suggesting that sorption to clay minerals is a likely controller of Te mobility. Investigation of Te species present in natural environments lends insight into basic Te geochemistry as well as guiding more controlled laboratory experiments.