Research Projects

Selenium (Se) and tellurium (Te) are rare metals classified as energy critical elements (ECEs) by the American Physical Society and Materials Research Society. They are essential for carbon-free energy production but are only recoverable in limited quantities. Se and Te are rarely found as native metals, but can be found as trace metals in base metal sulfides and sulfosalts, where they may be recovered as an economic by-product. Se and Te are considered environmental hazards at mine sites and beneficiation plants due to their potential adverse effects on the environment. However, the rising demand for carbon-free energy has increased the demand for minor metals like Se and Te used in thermoelectric and photoelectric device manufacturing. The majority of the world's output of Se and Te comes from porphyry and skarn copper deposits, where chalcopyrite is the predominant host for both elements. These elements are recovered as by-products during electrolytic refining of copper. Trace elemental studies of chalcopyrite show concentrations ranging from hundreds to thousands of parts per million. However, these investigations have only determined the concertation of Se and Te in natural chalcopyrite, which is insufficient in explaining the mode of occurrence, mechanism of incorporation, and limit of incorporation. Additionally, it is unknown what physico-chemical conditions exist in hydrothermal fluids that control the fractionation of Se and Te between liquid and solid phases. This research aims to conduct dry and hydrothermal experiments to understand the solubility limits and partitioning of Se and Te between hydrothermal solution and co-precipitated chalcopyrite under various pH-Eh and temperature conditions.