Real-Time Measurement Of Aqueous Cyanide In Mining Operations

A detection method and apparatus have been developed to perform real-time measurement of aqueous free cyanide, C-. A laboratory prototype can measure cyanide ranging from 5 micrograms ,per liter to 100 milligrams per ?liter for analysis times as short as 2 minutes per measurement. Sample size per measurement is typically only a few mI, thus? minimizing the waste volume produced from spent samples. The basis for this detection device is a quantifiable, stable affinity between the electrode material and free cyanide in the sample; The electrode exhibits piezoelectric behavior, allowing it to be used as a microbalance. This technology 'has experienced two generations of laboratory prototypes, and has been thoroughly tested to determine the operational sensitivity toward process variables such as pH, competing reactions, etc. The speed and ,accuracy of this method make it superior to conventional wet chemistry methods used for quantifying cyanide levels in water. A device based on this technology could be useful in areas involving process monitoring and environmental compliance, .particularly in the cyanide-based leach mining industry. Interest for this detector has been shown by the gold mining industry and others. Patent application is in progress.