Following a 24-hour strike, operations at Chilean copper mine Dona Ines de Collahuasi returned to normal, the company and the workers' union said.

Unionized workers at Chilean copper mine Dona Ines de Collahuasi downed their tools Saturday, the sole mine union said on its Twitter page. The strike comes on the heels of a now week-long stoppage at Escondida, the world's largest copper mine, which is fueling supply concerns in the copper market and driving prices higher. While Collahuasi represents about 3% of global output, Escondida, the world's largest copper mine, accounts for 7% of annual global copper production.

Lonmin PLC (LMI.LN), the world's third largest primary platinum producer, Thursday said it expects to meet its annual platinum sales target, provided there are no work stoppages, and raised its annual unit cost guidance to reflect reduced output in previous quarters. The U.K.-listed, South African miner expects to sell 720,000 troy ounces of platinum in the financial year ending Sept. 30 and expects annual unit costs to rise 11%, up from a previously forecast 8%, due to production setbacks stemming from industrial action and six fatalities during the first six months of the financial year.