Lluvia de Oro, Mexico

Click here for pdf version

BioteQ designed, built, and operated a solution processing plant using BioteQ’s patented ChemSulphide® technology combined with SART (sulphidization-acidification-recycle-thickening), developed by SGS Lakefield and Teck Corporation, at the Lluvia de Oro gold mine site in Sonora, Mexico. The plant recovered dissolved copper from cyanide solution and regenerated cyanide for re-use in gold extraction.

Brining together BioteQ’s ChemSulphide® process for metal recovery with the SART process for cyanide regeneration developed by SGS Lakefield and Teck Corporation, the plant removed and recovered copper from the cyanide leach solution produced by the gold heap leach operation, and regenerated the cyanide so that it can be recycled back to the gold operation. Constructed in 2008, the plant was designed with a capacity of 340 m3/hr, capable of recovering 900,000 pounds of copper and regenerating 2.8 million pounds of cyanide annually.

The plant was designed to produce a high-grade, saleable copper concentrate containing approximately 65% copper, to create an incremental revenue stream for the mine. By removing the metallurgical interference of copper from the gold leach process, the plant could enhance the recovery of gold on activated carbon, and improve purity of the gold-silver dore produced at the mine.

Up to 70% of weak acid dissociable cyanide was regenerated and recycled for gold recovery, reducing the quantity of cyanide required and the associated operating costs, while concurrently increasing environmental performance by eliminating copper-cyanide complexes in residual leach solution and recycling the copper off-site.

BioteQ’s services included process design, equipment procurement, construction, commissioning, operator training and operating services for the project.

Project Benefits:

The application of BioteQ’s technology at Lluvia de Oro had a number of process, environmental, and economic benefits. The plant was designed to:

  • Remove copper from the gold leach solution, improving the overall metallurgical performance of the gold operation, resulting in improved gold recovery and gold product quality.
  • Regenerate cyanide for the gold leach process, reducing the net consumption of cyanide for gold recovery.
  • Reduce operating costs for the gold process by reducing the quantity of cyanide reagent required to extract the gold.
  • Remove copper from the environment, reducing environmental liability while producing a saleable copper by-product that could create an incremental revenue stream and offsets treatment costs.