At the Grasberg mine, the sequencing of mining areas with varying ore grades also causes fluctuations in the timing of ore production resulting in varying quarterly and annual sales of copper and gold. FCX expects sales from Indonesia to approximate 0.7 billion pounds of copper and 0.9 million ounces of gold for the year 2012, compared with 846 million pounds of copper and 1.3 million ounces of gold for the year 2011. Indonesia's current sales estimates for 2012 are approximately 40 million pounds of copper and 45,000 ounces of gold lower than the July estimates because of mine plan changes in the Grasberg open pit, which delayed access to higher grade material, and a slower ramp-up of the DOZ mine. FCX expects sales from Indonesia to increase in the second half of 2013 as PT Freeport Indonesia gains access to higher ore grades.
Indonesia's unit net cash costs (including gold and silver credits) of $1.65 per pound of copper in third-quarter 2012 were significantly higher than unit net cash credits of $0.48 per pound in third-quarter 2011 primarily reflecting lower sales volumes.
Because of the fixed nature of a large portion of Indonesia's costs, unit costs vary from quarter to quarter depending on volumes of copper and gold sold, as well as average realized gold prices during the period. FCX estimates Indonesia's average unit net cash costs (net of gold and silver credits) would approximate $1.34 per pound of copper for the year 2012, based on current sales volume and cost estimates and assuming an average gold price of $1,700 per ounce for fourth-quarter 2012. Indonesia's unit net cash costs for 2012 would change by approximately $0.02 per pound for each $50 per ounce change in the average price of gold for fourth-quarter 2012. Assuming consistent commodity price assumptions, Indonesia's unit net cash costs for future periods are expected to be lower than 2012, as PT Freeport Indonesia accesses higher grade ore beginning in the second half of 2013.