The Sunrise Dam gold mine lies on the eastern shore of Lake Carey in the northern goldfields of Western Australia, some 770km north-east of Perth, 220km north/north-east of Kalgoorlie and 55km south of Laverton. It is 100% owned by AngloGold Ashanti.
Formerly just an open cut mine, the operation comprises of both a large open pit and an underground mine. Each commenced operations in 1997 and 2003 respectively.
The mine achieved record production of 401,000oz for 2009. Just 2.53moz was sourced from the underground mine.
The conversion of the mine’s diesel power station to liquefied natural gas (LNG) went according to plan in 2007 and the new LNG facility was expected to get operational by the second quarter of 2008. This was expected to drastically reduce energy costs as well as reduced greenhouse emissions. The conversion of the mine’s diesel power station to LNG was completed in the first quarter of 2009 instead of 2008, as there was an explosion at the site. This conversion is expected to cut down the power expenses for Sunrise.
Capital expenditure for the year amounted to A$39m (US $32m), and was spent mostly on the underground operation. A major portion of the amount was spent on the expansion of underground operations. About $8m (A$10m) was invested to build a paste fill plant. The plant will help in improving the productivity of the mine.
Some 360 people are employed at the mine, 255 of whom are contractors.
Geology and reserves
Gold ore at Sunrise Dam is structurally and lithologically controlled within gently dipping high-strain shear zones (for example, Sunrise Shear) and steeply dipping brittle-ductile low-strain shear zones (for example, Western Shear). Host rocks include andesitic volcanic rocks, volcanogenic sediments and magnetic shales.
Total ore reserves as of the end of 2009 were 1.73Moz. Total mineral resources were 3.62Mozoz Au.
Mining and processing
The mine comprises a large open pit, which is now in its 11th year of operation, and an underground mine, which began production in 2003. All the mining is carried out by contractors and ore is treated in a conventional gravity and carbon-in-leach (CIL) processing plant which is owner-managed.
Production and costs
Production for 2009 decreased 7% to 401,000oz, compared to 433,000oz for 2008.
The GQ zone in the open pit provided the anticipated large volumes of high-grade ore, which accounted for the increase in annual gold production. Some 157,000oz oz of gold came from the underground mine. Progress was made in developing access to the Cosmo, Dolly and Watu lodes, and 2,000m of underground capital development and 6,100m of operational development were completed. A total of 67,400m of diamond drilling was also completed.
Processing plant throughput in 2009 increased to 3.9Mt from 3.8Mt due to plant productivity improvement initiatives. Total cash cost increased to $646/oz from $531/oz (up by 17.8%).
Despite rising costs, the greater volume of ore mined, and the high value of the Australian dollar, the increase in production, due primarily to the higher grade of ore mined, resulted in the decrease in cash costs, year-on-year.
Sunrise expects to produce 381,000oz to 398,000oz of gold from the mine in 2010, with over 157,000oz produced from the underground mine. The underground production is expected to increase for the next few years, with a peak annual capacity target of over 200,000oz a year targeted for 2013.