We report a fluoride-free comparative study with promising results of an alkali-assisted roasting with KOH and water-based leaching of the Nigerian and Rwandan columbite-tantalite concentrates and application of guanidine ...

The nature of gold (Au) ore deposits plays an essential role in determining the best gold recovery method as an alternative to cyanidation, considering environmental concerns. Thiourea (Tu) leaching of gold is an alternative ...