Mining
Mining at the Chatree and Chatree North gold deposits is conducted by the Kingsgate Thai subsidiary, Akara Mining Limited (Akara). The method of mining is by open cut and utilises simple drill and blast technology, after initial drilling to accurately determine the gold grade of each block of rock. Each block is marked into a category dependant on the gold grade and also identifies the waste rock. Excavators and hydraulic loaders shift the blasted gold-mineralised rock and load it into a fleet of trucks. The ore is trucked either to the processing plant via the Run-Of-Mine (ROM) stockpile or to a stand-by stockpile for later processing. Waste is trucked to a waste rock dump.

Lotus Hall, a Thai based mining contractor, was introduced to contract mining by Akara in 2001 and has grown substantially since, with other mining projects in Thailand and Laos.

The drilling is performed by a global drilling services company introduced to Thailand by Akara in 1995, Boart Longyear Asia Pacific, who have an office established in Chiang Mai and a technical services base adjacent to the Chatree mine.

Processing
The Chatree Gold Processing Plant uses a simple, proven ore dressing technique called Carbon-in-Leach (CIL) which has a capacity of processing approximately 2.3 million tonnes of ore per annum (2.3mtpa). This technique takes low-grade gold mineralised rock, containing 1-2 grams of gold per tonne of rock, which is then crushed into a fine powder in the plant's grinding circuit. Water and reagents for extracting gold, including a weak cyanide solution, are then mixed with the powdered rock and activated carbon to separate approximately 90% of the gold and 35-45% of the silver. The gold-silver product is then poured as "doré" bars. The doré is refined in Hong Kong into the pure gold (999 fine gold) and pure silver necessary to sell the product on the international market.

The fine powdered waste is stored in a tailings storage facility (TSF) and most of the water and reagents are recycled for further use. Non-toxic host minerals including carbonate, chlorite, clay and silica exist with the gold which means that processing can occur without generating any chemical complexes that are difficult to manage. The most common leaching agent used in the gold industry is sodium cyanide. Any cyanide that is not able to be recycled within the plant is chemically destroyed to non-toxic total cyanide levels of 5-10 parts per million (ppm) - similar to that contained in a cup of instant coffee - and contained for further breakdown in the tailings storage facility. [more - see powerpoint slides (Op slides) flowsheet and description]