Cyanide analysis for complex cyanide solutions
CIM Journal, Vol. 4, No. 2, 2013
W. van der Merwe
Measurement and Control Division, MINTEK Randburg, South Africa
Parker CRC for Integrated Hydrometallurgy Solutions, CSIRO Minerals Down Under National Research Flagship, CSIRO Process Science and Engineering, Australia
With the gold industry processing more complex ores, the online measurement and control of cyanide addition to the gold leaching circuit has become more critical. This paper compares the two commonly employed ‘free’ cyanide online analysis methods (amperometric and potentiometric endpoint silver nitrate titration) with the rhodanine endpoint silver nitrate titration and ion selective electrode methods common at site laboratories. Measurement differences between these methods are presented and discussed for cyanide solutions containing copper and zinc with varying cyanide to metal ion ratios. The resulting cyanide available to leach gold is also compared using these measurement techniques.