Treatment of cyanide by using the Mexican modification of the Merrill-Crowe process

Cyanide consumption can be a major factor which contributes to operating cost for cyanidation. Also after extraction and recovery of precious metals substancial amounts of cyanide are delivered to tailings ponds which creates environmental problems due to the toxicity of cyanides. In this regard, the air-sparged hydrocyclone (ASH) has been used as a reactor for the treatment of cyanide solutions in two ways; first for cyanide recovery by acidulation using the Mexican modification of the Merrill-Crowe process and second for cyanide destruction by oxidation with the use of chlorine dioxide (C102). In both cases excellent performance can be archieved using the high capacity ASH technology.