BioteQ currently operates a plant in the US, in a joint venture with a large mining firm. Following evaluation of several potential project opportunities in the US, BioteQ signed a joint venture agreement in October 2002, which led to the construction and commissioning of a plant using BioteQ's BioSulphide® Process in 2004 at an inactive mine site.


The plant recovers copper from the drainage of a large low-grade stockpile, which had been previously under leach with copper recovered by cementation with iron. Leach solution draining from the stockpile passes to the BioSulphide® Plant where copper is precipitated into a high-grade copper sulphide concentrate using hydrogen sulphide reagent generated in a bioreactor in which elemental sulfur is reduced.

The copper concentrate, containing typically 40 to 45% copper, is shipped to a smelter, where it is processed under commercially competitive terms. The capital cost for the plant was approximately US $3.2 million, which was paid back within 2 years. The plant capacity is estimated to be 3 million lbs/year of copper. In 2007, the plant recovered 1.4 million lbs of copper, of which BioteQ was entitled to half under the terms of the JV; BioteQ’s share of operating costs were about $1.2 million for the year. It is estimated that the total amount of copper contained in the stockpile is over 400 million pounds. Work is in progress to optimize water management and copper extraction from the low grade stockpile.

Project Benefits

The application of BioteQ's technology at this site provides immediate economic benefit from copper recovery as well as long term potential economic and environmental benefits, including:

• Copper recovery from stockpiles at the site
• Increased rate of copper extraction from existing stockpiles
• Reduced operating costs for site water management
• Contribution to eventual closure plan for site
• Demonstration of the BioteQ process for application at other mine sites for copper recovery and water management.