MMSA is pleased to announce the first commercial application of its CN-D cyanide destruction process at Randgold Resources new 300000tpm Tongon Gold Mine in Cote d’Ivoire West Africa is due for commissioning in the last quarter of 2010. As the Tongon ore is refractory it will also be treated using Maelgwyn’s Leachox™ process to treat a flotation concentrate and tails.
The Maelgwyn CN-D™ process was selected after an intensive testwork program and is able to reduce the weak acid dissociable cyanide to less than 0.5ppm in the residue which is low enough to be discharged to the environment.
In the CN-D Process free and WAD cyanide are oxidised by Aachen reactors using oxygen and activated carbon at specific Eh and pH values .The optional use of a metal catalyst can further reduce cyanide levels. Apart from its inherent simplicity the process by utilising activated carbon has the added advantage of acting as a “policeman” or safety net to further reduce any residual soluble loss of gold. The Aachen reactors are also able to drive leach kinetics using the remaining residual cyanide prior to destruction to dissolve additional gold .This combined gold from additional dissolution and adsorption can provide a credit which at times can cover the entire cost of the CN-D process and contribute towards reducing overall operating costs.