Justification of the possibility to involve productive fractions of the off-grade polycomponent ores in processing

During open-pit mining, large volumes of off grade ores are delivered to the surface and dumped along with various grades of commercial ores. These ores may generally contain a significant amount of the useful metal, but their average grade does not allow for profitable processing of this mineral raw material, even with the use of heap leaching. At the same time, being blasted many ores produce ore fines that contain significant amounts of useful components. The conducted experimental studies of oxidized off-grade polycomponent ore from one of the copper-porphyry deposits showed an increased content of copper in the –15 mm size class, as well as gold and copper in the –2.5 mm size class. The article proposes a process flow diagram that involves separation of productive small and fine fractions from the off-grade ore by means of dry and wet screening, which are sent for separate processing using heap and cuvette leaching, respectively. Staged cuvette leaching of the productive fine fraction will ensure a relatively high extraction of metals into the productive solution in comparison with heap leaching. Implementation of the technology will significantly reduce the amount of metal lost with the off-grade ores.