Contractors protest at BHP Billiton's Escondida in Chile

Contract workers blocked some roads to Chile's Escondida copper mine, the world's largest, on Thursday in a bonus dispute, although production operations weren't halted, reports local newspaper La Tercera.

Escondida, owned by BHP Billiton (NYSE: BHP), produced 819.261 tons of copper last year.

Earlier this year, BHP CEO Marius Kloppers, said he expected a significant production increase at the copper mine to over 1.3Mt/y in the 2015 financial year.

“This is a more than 600,000t copper uplift over 2010,” Kloppers said, adding that in terms of mine equivalence “it is sort of like adding another Chuquicamata or Collahuasi.”

Escondida, one of the lowest cost producers, it is currently undergoing a  $544 million optimization known as the Escondida Ore Access (EOA) project. The development plan will relocate the primary crusher and conveying system to access higher-grade ore and increase output from 2013.

Kloppers said that the completion of the EOA project would facilitate a recovery in the grade profile to well over 1% copper through the second half of this year.