Comparison of process alternatives for gold recovery from cyanide leach solutions

Both conventional and nonconventional process alternatives for gold recovery from cyanide heap leach solutions are discussed in terms of possible flowsheets. Conventional process alternatives include carbon adsorption and zinc dust precipitation, while nonconventional process alternatives include resin ion exchange, solvent extraction, and direct electrowinning. These strategies for gold recovery are compared on the basis of technological features and on the basis of process economics. Review of the technology status and process economics suggests that improvements for conventional process alternatives are possible and that further development of nonconventional process alternatives is warranted.