Goldcorp has achieved first gold at the Pyrite Leach project (PLP) at its Peñasquito operation in Mexico.

Commissioning commenced in the September quarter and the PLP is now processing 100% of the existing plant tailings, with the PLP plant operating 24 h/d as it continues to ramp up.

David Garofalo, President and Chief Executive Officer of Goldcorp, said the project was a major investment decision for the company and one of the first that went through the “Goldcorp Investment Framework”.

“We are very pleased with the results in completing the project both ahead of budget and schedule. We are already moving forward with a post investment review where we can take our lessons learned to continue to improve our framework and overall capital allocation strategy,” he said.

The PLP is part of Goldcorp’s $420 million investment to improve the processing facilities at its Peñasquito operation. It is expected to recover some 35% of the gold and 42% of the silver currently reporting to the tailings and add production of over 1 Moz of gold and 45 Moz of silver over the current life of the mine.

The PLP plant processes the existing plant tails, feeding a sequential flotation and leach circuit with precious metals recovered through a Merrill Crowe process, producing doré as the final product. Tails from the new plant will report to the existing tailings storage facility. As the plant is ramped up to achieve design recovery, there will be ongoing optimisation of the circuit chemistry and regrind performance.

Goldcorp highlighted that the PLP was delivered with over 9.5 Million site-hours, zero lost time incidents and an industry-leading all injury frequency rate of 0.09. It was constructed by a 100% Mexican workforce, commissioned two quarters ahead of schedule and came in 9% under the $420 million budget.

Commercial production is now expected by the end of 2018, two quarters ahead of plan, the company said.

The carbon pre-flotation circuit (CPP), which is integral to the performance of the PLP and existing plant, was commissioned in the June quarter as planned and the circuit has now treated 6 Mt of high-carbon ore and is operating and exceeding initial performance expectations.

The completion of the CPP de-risks not only stockpiled material, it also enhances flexibility to sequence ores and has the capability to process the complex organic carbon ore types remaining in the reserves. CPP achieved commercial production on October 1.

The CPP circuit currently consists of three stages of flotation to remove organic carbon from the cyclone overflow prior to the existing lead flotation circuit.