Workers have gone on strike at Chile’s Chuquicamata copper mine, the world’s largest open pit copper mine (MARTIN BERNETTI)

Santiago (AFP) – Workers employed by the world’s top copper producer went on strike Friday at the sprawling Chuquicamata mine in Chile, unions said.

Three unions issued a statement saying adherence to the open-ended stoppage was massive at the mine operated by the state-owned company Codelco.

Codelco produces more than a third of the world’s copper.

The miners are demanding wage increases and other improvements in working conditions, in particular health care for workers who are about to retire.

The strike follows the break down of two weeks of talks between unions and management. The company had said its offer took into account “the reality of the mining sector” and its future prospects.

The mine produced 320,000 fine metric tons of copper last year. Economists estimate one day of downed tools will cost the company 1,000 tons of copper and around $5.8 million (5.1 million euros)

The mine employs 4,600 people. Unions said 3,200 of them were on strike.

One of the unions tweeted pictures of strikers waving red, white and blue Chilean flags at gates leading into the facility.

Located in the harsh Atacama Desert in northern Chile, Chuquicamata is considered the world’s largest open pit copper mine.

The strike comes at a delicate moment. After operating for more than 100 years as an open pit, Chuquicamata will shift in July to underground block cave mining after an investment of $5.8 billion.

Unions want better health care, especially for workers leaving the mine because of the transition to digging underground.

Disclaimer: Validity of the above story is for 7 Days from original date of publishing. Source: AFP.