APPLICATION OF THE GANGUE REJECTION AMENABILITY TEST (GRAT) FOR GOLD ORES

摘要

Rejection of gangue by means of gravity based separations prior to intensive, and costly, grinding can lead to numerous advantages. These benefits include processing of a higher feed grade at a higher net throughput by rejection of a sufficiently waste stream, the creation of dual product streams (e.g. high grade and low grade) that can be processed separately, or, when possible, the rejection of deleterious elements (i.e., preg-robbing carbonaceous material or cyanide consuming copper minerals) prior to downstream processing. Ultimately, the application of gangue rejection may increase profitability for existing operations and may lead to the conversion of otherwise uneconomic material into ore reserves. Curtin University has developed a method for assessing the gangue rejection amenability for gold ores in the hydraulically pumpable size range. Using this method, a database of results from the gangue rejection amenability test (GRAT) containing 11 different ores, and 20 unique datasets has been generated. This database has been interrogated to determine the optimal gold loss vs mass rejected response based on size or density based separations for each sample and the database can now be used for benchmarking.