The Jinfeng mine is Sino Gold's flagship project and is the second largest gold mine in China. Sino Gold Limited (SGL) holds 82 per cent equity in the Sino-Foreign joint venture Sino Guizhou Jinfeng Mining Limited (SGJML) with a Chinese partner._x000D_
Jinfeng is located in a relatively remote site in southwestern Guizhou province. The orebody is considered to be the largest known Carlin type deposit in China._x000D_
Jinfeng Plant has the world's third largest BIOX bacterial oxidation facilities (790 t/d), treating highly refractory concentrate generated from crushing, semi-autogenous grinding (SAG) and ball milling and bulk sulfide flotation operations. The Jinfeng Plant construction started in February 2005, commissioning was completed in April 2007, and commercial gold production was achieved in September 2007._x000D_
This paper describes the successful operations of Jinfeng Plant over the last two years. The key events of the project development are described, from the project background and process design, through to the commissioning and achieving design mill throughput of 3600 t/d resulting 180 000 ounces of gold per year._x000D_
Process aspects of the BIOX and carbon-in-leach (CIL) operations over the last two years are discussed which illustrate a very high BIOX oxidation rate (more that 97 per cent) and excellent CIL recovery (more than 96 per cent)._x000D_
The management of the Jinfeng plant CIL tailings detoxification and filtration is described, and Jinfeng has became the first BIOX processing plant to have achieved dry stacking of detoxified and pressure filtered CIL tailings. Current efforts to recover cyanide from CIL detoxified solution and the achievement of a zero discharge site water balance are also introduced._x000D_
Many improvement projects have been made over the last two years which have culminated in a 15 per cent increase in mill throughput over the design and BIOX CIL recovery increasing from 92.5 per cent to 96 per cent._x000D_
Significant operating cost reductions from lowered of acid, lime and cyanide usage through process modifications and technical innovations are discussed.