First Solar signals interest in US tellurium supplies for solar panel production

From pv magazine USA

Rio Tinto plans to spend nearly $3 million on a facility to recover tellurium, a critical mineral used in solar panels, from its Kennecott mine near Salt Lake City, Utah. And First Solar said it is now in talks with the mining group to procure the mineral for cadmium telluride (CadTel) semiconductor processing in the United States.

The mineral is a byproduct of copper smelting. Rio Tinto said it expects to start production in the fourth quarter. Its Utah plant will be able to produce around 20 tons of tellurium per year.

First Solar uses a layer of CadTel semiconductor that is 3% the thickness of a human hair. It said that CadTel is efficient, cost-competitive, and fast to produce, helping it to make its modules in around 4.5 hours. First Solar said that CadTel technology has a carbon footprint that is around 2.5 times lower than crystalline silicon panels.

First Solar sources its CadTel from suppliers in the United States, Canada, and Europe. It declined to disclose quantities or names of suppliers, but said that Rio Tinto’s supply, if contracted, “could add to existing sources.”

For its part, Rio Tinto is looking to extract more from each rock it mines in order to reduce waste and meet demand for critical minerals.

Tellurium also can be used as an additive to steel and copper to improve machinability, making these metals easier to cut, as well as added to lead to increase resistance to sulfuric acid, vibration, and fatigue.

Kennecott’s smelting process in Utah also recovers gold, silver, lead carbonate, platinum, palladium, and selenium. Elsewhere, Rio Tinto is investing in facilities to extract battery-grade lithium from waste rock at its Boron, California, mine site, and scandium oxide from waste streams at a complex in Sorel-Tracy, Quebec.