Dec 14 (LTIT) – Three unions at Codelco’s Chuquicamata mine downed tools late Wednesday and blocked access to the century-old operation, claiming that the Chilean copper miner has been violating agreements with workers and threatening union leaders.

A spokeswoman for the company, the world’s No. 1 copper producer, told MINING.com the mine was operating normally, adding that the blockage has not prevented workers from showing up at work.

Unions claim Codelco has failed to properly include workers in the mine redesign and said there were ongoing issues with healthcare provisions.

Unionized staff at Chuquicamata, Codelco’s second largest by size, have protested for months over plans to convert the massive open pit into an underground mine, which is one of the main goals of the company’s $39 billion, 10-year plan to update its aging deposits.

The current bone of contention seems to be a collective agreement covering health care benefits, according to a statement posted Thursday by Union No.1.

"It’s estimated that about 1,700 employees will lose their jobs as a result of the mine becoming an underground operation only and Codelco is not offering any type of health benefits as part of the retirement plan for most of those workers," the union said.

“We’re conscious of the fact that the redesign is a necessity for Chuquicamata, but we also know that the process should be inclusive … of workers and that has not been respected,” it said.

The $4.9 billion-switch, expected to be completed by mid-2019, will extend Chuquicamata’s life by another 50 years, allowing Codelco to keep production rates, despite falling ore grades and increasing costs at its assets.

Last year, “Chuqui” — as locals call it — produced 330,900 tonnes of copper, out of the company’s total of 1.734 million tonnes. Annual production from the 103-year-old mine after the transition from surface to underground is projected to be 320,000 tonnes of fine copper and 15,000 tonnes of molybdenum.

Codelco, which hands over all of its profits to the state, holds vast copper deposits, accounting for 10% of the world's known proven and probable reserves and about 11% of the global annual copper output with 1.8 million metric tonnes of production.