The Sunrise Dam Gold Mine is located 55 km south of Laverton, Western Australia, on the eastern margin of Lake Carey. It is fully owned by AngloGold Ashanti and comprises a large-scale mechanized underground mine with a conventional gravity and leach process plant. In 2015 the mine accounted for 5% of the company's production.
History
The gold deposit was originally co-owned by the Granny Smith Joint Venture (Placer Pacific Ltd and Delta Gold NL), which called its eastern portion "Sunrise", and by Acacia Resources Ltd, which called its western portion "Cleo".
The Sunrise portion was found in August 1988, after a 500m by 500m BLEG survey. The Sunrise mine commenced operations in May 1995.
The Cleo portion was first indicated by tenement-wide rotary air blast and aircore drilling in 1991. Acacia Resources commenced production in February 1997, with the first gold pour in March that year. The Sunrise Dam gold mine was officially opened by Premier of Western Australia Richard Court on 6 August 1997.
In 1999, AngloGold acquired the mine through a takeover of Acacia Resources Ltd, a move that also gained it a 33% stake in the Boddington project, which it sold in early 2009 for $1.5 billion. Acacia, originally formed and listed in 1994 when Shell Australia divested its gold and base metal activities, was delisted from the Australian Stock Exchange on 11 January 2000.
An upgrade to the processing plant took place in 2001, the expansion initially designed for 2.5Mtpa, however by year-end plant throughput had been further increased to 3Mtpa. As a result, gold production increased by 31% in 2001, to 295,000oz. A major cutback in the Cleo pit was completed during the year, whilst the corporate office was restructured and relocated from Melbourne to Perth.
Following the capital expansions undertaken the previous year, gold production increased by 30% in 2002 to 382,000oz, as plant throughput rose by 41% to an annual rate of 3.4Mtpa. After completion of a major cutback at the end of 2001, mining in the Mega Pit reached full capacity in the first half of 2002. A smaller cutback, in the Watu section of the pit, was approved during the year.
In December 2002 AngloGold purchased the Sunrise lease from Placer Dome, obtaining control of the entire mineralised system at Sunrise Dam.
During the first half of 2004 an underground scoping study was completed. Deep drilling indicated the sub-vertical, high-grade zones, that had been a feature of open-cut mining at Sunrise Dam, continued at depth. Underground mining commenced later that year, initially as a three-year feasibility project incorporating two declines in the vicinity of defined underground reserves. The primary decline was named the Daniel Decline, after prominent local indigenous businessman Daniel Tucker.
Abnormally heavy rainfall limited access to high-grade ore in the pit early in 2004. As a result, mining moved into the higher-grade Watu section of the orebody, with production increasing by 15% to 410,000 ounces. First gold produced from the underground mine was in the fourth quarter of 2004.
In 2005, open cut mining continued in the high-grade areas in the first half of the year, then onto the lower grade northern section of the pit from the third quarter. Open pit ore was supplemented in the processing plant by higher grade underground ore. Gold production increased by 11% to 455,000 ounces.
Production increased slightly in 2006 to 465,000 ounces. Mining concentrated on the high-grade GQ lode in the open pit. Mining from the known underground reserves increased significantly, especially in the Sunrise and Western Shear zones. Gold production from the underground mine was 67,000 ounces. Record throughput of 3.9Mtpa was achieved in the process plant as a result of additional crushing and grinding circuit optimization.
In 2006, AngloGold Ashanti signed a contract for conversion of its diesel power generators to liquefied natural gas (LNG) as a cost-saving measure as well as to protect the environment. The conversion was delayed by an explosion at the Varanus Island gas production installation and subsequent 2008 Western Australian gas crisis. The LNG-powered facility at Sunrise Dam began operation in the first quarter of 2009.
2007 saw production increase by 29% to a record 600,000 ounces. The GQ zone in the open pit provided the anticipated large volumes of high grade ore. Approximately 79,000 ounces of gold production was sourced from the underground mine. Progress was made in developing access to the Cosmo, Dolly and Watu lodes. A cutback of the north wall of the open pit began (North Wall Cutback), while the underground life of mine study was completed.