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Fiscal concerns and new environmental regulations regarding the transportation and destruction of cyanide have led to a renewed interested in recovering cyanide and copper from gold processing operations.


SGS is the world leader in cyanide recovery technologies. The innovative new Hannah Process for cyanide recovery, developed in SGS laboratories, effectively addresses both of these concerns.

The Hannah Process is particularly well suited to the recovery of copper cyanide, and can be applied to cyanide in solutions or pulp. The process uses a strong base resin technology to extract free cyanide radicals as well as metal-cyanide complexes from gold tailings. The process offers a number of important benefits including:

  • Efficient extraction of free cyanide and metal cyanide complexes in 2 or 3 adsorption stages
  • Rapid elution of cyanide and base metals under ambient conditions
  • Separation and recovery of valuable by-products in the eluate, including copper compounds
  • Significant cost savings. The Hannah Process allows you to efficiently recover the cyanide from your solutions or pulp at one quarter to one sixth of the average cost of traditional recovery techniques
  • Increased plant safety. Cyanide is recovered for direct recycle-to-leach, without volatilizing toxic hydrogen cyanide gas (HCN)
  • Reduced transportation costs and lower risk of spills during transport-to-site. Cyanide recovery saves you money on transportation and decreases your environmental risks
  • Regulatory compliance. Cyanide recovery enables you to comply with strict new environmental regulations concerning cyanide in gold tailings 

Contact SGS early in the planning and proposal stage of your gold recovery operation. We offer a number of cyanide recovery solutions to improve your bottom line while meeting safety and environmental regulations. Allow our technical experts and chemists to work along with you to decide if the Hannah Process is a viable option for your gold processing flowsheet.