Her stress exposure is many times higher than mine.

FORBES: How to Turn Your Man into Mr. 50%

Rollinson said mine optimization will be a factor going forward and that the company will focus on margin increases, rather than higher mine production at any costs.

FORBES: Kinross: Main Focus Will Be On Increasing Margin And Prioritizing Cash Flow

It quotes a review in Zambia which found that between 2005 and 2009, 500, 000 copper mine workers were paying a higher rate of tax than major multinational mining firms.

BBC: Kofi Annan: Africa plundered by secret mining deals

The production of gold from the Grasberg mine alone is expected to rise by 40% higher than the levels seen in 2012.

FORBES: Freeport Banks Future On Better Copper Production And Energy Exploration

Workers at the Marikana mine returned to work last month after receiving pay rises far higher than the rate of inflation.

BBC: South African mine owner Amplats fires 12,000 workers

Freeport blamed this drop largely on changes to mine plans at the Grasberg mine in Indonesia, which delayed access to higher-grade material, and a slower-than-expected ramp-up at the Deep Ore Zone underground mind.

FORBES: Freeport Copper, Gold Output Falls In 3Q But Expected To Rise Again As Indonesian Production Picks Up

Although production in the next two years is forecast to be lower than the average achieved over the last five years, it is expected to return to higher levels as the mine transitions to higher grade, but lower carat value, ore from the Misery and Pigeon open pits.

FORBES: Harry Winston to Purchase Ekati Diamond Mine For $500 Million