Challenges and Opportunities in tellurium supply

Tellurium is vital to a number of emergent and growing technologies, including photovoltaic power and thermoelectric devices. It is however, one of the rarest elements in the Earth's crust, and future supply of Te is not without challenges. At present, Te is almost exclusively sourced from the reprocessing of waste materials from copper refining. There is potential for an increase in Te production from this source, but production statistics indicate that there has actually been a decrease in the efficiency of Te supply from this source. Alternatives are deposits in which Te is the dominant product (e.g. Dashuigou, China; Moctezuma, Mexico), mines where Te is a by-product (Kankberg), or mines in which Te may be recovered as a by-product. Tellurium enrichments are reported from epithermal Au, orogenic Au, VMS, IOCG and Carlin-type deposits. In many deposits, Te is likely hosted in pyrite abundant but relatively low grade, and not always considered an ore phase. Tellurium in pyrite is unlikely to be recoverable with current technologies. Where Te occurs as stoichiometric component of gold, silver and other metal/metalloid minerals, recovery may be targeted. Co-recovery with precious metals is key to economic supply of Te.