CUHRIG/E+ via Getty Images

CUHRIG/E+ via Getty Images

Rio Tinto (NYSE:RIO ) subsidiary Kennecott Exploration said Monday it started drilling on the Copper Gulch prospect of Alderan Resources' (OTCPK:ALDRF) Frisco project in Utah.

The company says Copper Gulch is a porphyry copper target southwest of the copper-rich tourmaline beccias at the historical Cactus copper mine.

Frisco is the subject of an option agreement between Kennecott and Alderan's Volantis Resources subsidiary; Kennecott can earn up to 70% in Frisco by spending at least $30M in three stages over 10 years.

Separately, Russian aluminum producer Rusal (OTC:UNRIF) has filed a lawsuit against Rio Tinto (RIO), seeking to win back access to its 20% share of the alumina produced at a jointly owned refiner in Queensland, Reuters reported on Monday,

Rio (RIO) stepped in to take sole control of Queensland Alumina in April, cutting Rusal's access to the refinery's alumina production; Rio owns 80% of the refinery, while Rusal owns the remaining 20%.

"With shares just above a strong 10-year support base, Rio offers an exceptionally asymmetric risk/reward opportunity," Brian Kapp writes in a bullish analysis posted recently on Seeking Alpha.