At the Grasberg mine, the sequencing of mining areas with varying ore grades 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 1.1 billion pounds of copper and 1.2 million ounces of gold for the year 2013, compared with 716 million pounds of copper and 915 thousand ounces of gold for the year 2012. FCX expects sales from Indonesia to increase in fourth-quarter 2013 as PT Freeport Indonesia gains access to higher ore grades and achieves the targeted ramp up in production from the DOZ mine. Approximately 33 percent of Indonesia's projected copper sales and 38 percent of projected gold sales are expected in fourth-quarter 2013.
Indonesia's unit net cash costs (including gold and silver credits) of $1.33 per pound of copper in fourth-quarter 2012 were lower than unit net cash costs of $3.57 per pound in fourth-quarter 2011 primarily reflecting higher sales volumes. Fourth-quarter 2011 costs also included $66 million, or $1.30 per pound of copper, for bonuses and other strike-related costs.
FCX estimates Indonesia's unit net cash costs (net of gold and silver credits) would approximate $0.68 per pound of copper for the year 2013, based on current sales volume and cost estimates and assuming an average gold price of $1,700 per ounce. Indonesia's unit net cash costs for 2013 would change by approximately $0.055 per pound for each $50 per ounce change in the average price of gold. Because of the fixed nature of a large portion of Indonesia's costs, unit costs vary from quarter to quarter depending on copper and gold sales volumes, as well as average realized gold prices for the quarterly period. Indonesia's unit net cash costs for first-quarter 2013 are expected to approximate $1.57 per pound of copper and are expected to decline in future quarterly periods as volumes increase.