Spanish media report that 85 per cent of the 800 workers at First Quantum Mineral's Cobre Las Cruces mine in Spain went on strike in demand for the payment of 'toxic bonuses' (hazard pay) for subcontractors.
What they call 'toxic bonuses' are additional payments for work that is particularly risky.
According to EFE news agency, the spokesperson for the Comisiones Obreras union, Juan Antonio Caravaca, said the strike began early on Friday and no major incidents were reported except for the detention of some administrative staff along the road that leads to the mine.
The protest action, which on Friday was accompanied by a picket line at the entrance of the mine, is supposed to last for four days and is to be joined by both permanent staff and the workers of at least eight subcontractor companies.
MINING.com reached out to First Quantum Minerals for comment but did not receive an answer by publication time.
Cobre Las Cruces, operated by a local subsidiary of FQM, is a copper mining complex with an open pit mine and hydrometallurgical processing plant.
The 946-hectare site straddles the municipalities of Gerena, Guillena and Salteras, located in the southern Spanish province of Seville, and it sits on top of the Iberian Pyrite Belt. Reserves are estimated at 17.6 million tonnes of ore grading 6.2% copper.
According to the company's website, expected annual production averages 72,000 tonnes of copper, equivalent to 25% of Spanish internal demand.