PERTH (miningweekly.com) – Diversified miner Rio Tinto has started tellurium production at its Kennecott copper operation in Utah, becoming one of only two US producers of the critical mineral used in advanced thin film photovoltaic solar panels.
The tellurium will be refined in North America by 5N Plus, a global producer of specialty semiconductors and performance materials, under a commercial agreement between 5N Plus and Rio Tinto.
The refined tellurium will primarily be supplied to First Solar, the only American company among the world’s ten biggest solar manufacturers, under an existing supply contract between 5N Plus and First Solar. 5N Plus will also use the tellurium to manufacture ultra-high purity semiconductor materials at its facility in St. George, Utah, to serve the security and medical imaging markets.
Rio said this week that some 20 t/y of tellurium will be produced through a new $2.9-million circuit built at the Kennecott refinery. This material is recovered from by-product streams generated during the copper refining process, reducing the amount of waste that needs to be treated and discarded as mine tailings.
Tellurium is listed as a critical mineral by the US government, owing to its importance to the economy and energy security, and is one of ten metals and products recovered from ore extracted at Kennecott, which produces nearly 15% of US copper with the country’s lowest carbon footprint.
“We are proud to deliver a new domestic supply of tellurium to support the manufacturing of solar panels and other critical equipment here in the US. Approximately 90% of the world’s tellurium resource is contained in copper ore and no other metal has more critical mineral by-products than copper,” said Rio’s copper COO, Clayton Walker.
“The Kennecott team is constantly looking for ways to extract new critical minerals to meet emerging demand for the clean energy transition.”