| Name | Sepon | |
| Location | Located approximately 40 kilometres north of the town of Sepon, in Savannakhet Province, south-central Laos | |
| Workforce* | Over 5,080 (Sepon Copper and Sepon Gold) | |
| Sepon Copper | Sepon Gold | |
| Product | Copper cathodes | Gold and silver doré |
| Mining Method | Open pit | Series of open pits |
| Processing Method | Whole-of-ore leach, solvent extraction electrowinning (SX-EW) | Conventional carbon-in-leach (CIL) |
| Commenced Operation | 2005 | 2002 |
| Reserves** | 792,000 tonnes copper | 0.18 million ounces gold |
| Resources** | 1.8 million tonnes copper | 3.3 million ounces gold |
| 2008 Production | 64,075 tonnes copper cathode | 93,072 ounces gold |
| Sales | Cathodes are transported via road and sea to customers in south-east Asia | Doré bars are transported by air freight to a refinery in Australia |
| * Includes all employees (full-time, part-time and casual) and contractors as at 31 December 2008 | ||
| ** As at 30 June 2008 (see OZ Minerals ASX Release 23 December 2008 for full statement of Mineral Resources and Ore Reserves) | ||
The Sepon gold and copper operation comprises a 1,250 square kilometres contract area located approximately 40 kilometres north of the town of Sepon in Savannakhet Province, south-central Laos. The Government of Laos holds a 10 per cent interest in Sepon with OZ Minerals owning the other 90 per cent.
Sepon Copper
The Sepon copper operation commenced operation in 2005 and has consistently produced more than 60,000 tonnes of copper, as cathodes, annually. The Sepon copper operation is based on mining the very high-grade (+5 per cent) Khanong orebody. The newly discovered, smaller, Thengkham and Phabing deposits will also be mined.
The installation of a second autoclave, designed to increase copper recovery, process reliability and reduce production downtime, was commissioned in the first quarter of 2009.
OZ Minerals had commenced work on an expansion to the Sepon copper operation but this was suspended until after 2009 due to financial constraints.
In 2008, a record 64,075 tonnes of copper cathode was produced. Production for 2009 is forecast to be 65,000 - 70,000 tonnes of copper. Sepon copper is sold to manufacturers of cable, wire and tubes in neighbouring countries including Thailand, Vietnam, Malaysia and China.
Sepon Gold
Gold has been produced at Sepon since December 2002 and in early 2005, an expansion of the original gold processing facility doubled the capacity of the gold processing plant, to 2.5 mtpa.
In 2008 the operation produced 93,072 ounces of gold. Production for 2009 is forecast to be 90,000 - 105,000 ounces. Gold doré bars produced at Sepon are transported to refineries for refining into gold bullion. These bars are then sold to jewellers, manufacturers and banks.
The Sepon area contains significant resources of primary gold mineralisation. While this material can not be treated in the current plant, a modification to the existing plant could enable processing of this gold ore. Pre-feasibility study work carried out previously indicated that additional primary gold resources are needed to justify such an expansion and work to increase the resource base is ongoing.
Exploration
New discoveries continue to be made in the Sepon district and exploration for both copper and gold is ongoing with many targets remaining to be assessed. Exploration for further copper resources at Sepon is focused around the Khanong deposit, which is currently being mined, and on the Thengkham and Phabing deposits which lie seven kilometres to the west of Khanong.
Drilling continued to deliver excellent primary copper-gold results at Thengkham East and new zones of primary copper mineralisation were outlined for follow-up drilling at Thengkham South. A large-scale geophysics survey undertaken in 2008 will aid in targeting gold and copper mineralisation in 2009.
Exploration for gold at Sepon is ongoing. Resource definition drilling in 2008 confirmed Houay Yeng as a new high grade open pit gold deposit. Seven kilometres east of the Sepon Gold plant, drilling at the Houay Bang target intersected moderate-high grade (primary) gold mineralisation.
