Effect of mineralogy on grindability -A case study of copper ores

Abstract

The effect of mineralogy on the grindability was investigated using three copper ores - two sulphides and one oxide. The dominant copper minerals were identified by optical microscopy and mineral chemistry derived from SEM-EDS analysis. The sample designated sulphide 1 was bornite-rich, sulphide 2 ore was mainly chalcopyrite, and the oxide ore was predominantly malachite and minor azurite. The gangue minerals were identified using semi-qualitative XRD analysis. Sulphide 1 contained more than 80% (w/w) of quartz compared to about 70% in the other two ores. The Bond work indices were 13.8, 21.6, and 17.3 kWh/t for sulphide 1, sulphide 2, and oxide ore respectively. This suggested that the chalcopyrite-rich ore is the hardest, while the malachite-rich ore has intermediate hardness, and the bornite-rich ore is the softest. The brittleness indices of the ores were calculated using the chemical composition of the gangue, and a good correlation between brittleness indices and Bond work indices was observed, which highlights the importance of the gangue composition in determining the fracture behaviour of the ores. There is scope for further investigation into the relationship between ore mineralogy and comminution behaviour using other breakage characterization techniques.

Geometallurgical Simulation of the Work Index in a Porphyry Copper Deposit Using Geostatistical Techniques

“…followed by mixed and finally oxides; which is related to the works developed byHarbort et al (2013),Harbort et al (2011) andNghipulile et al (2023) ; however, in each study, there is a variation in the values for BWi due to the specific characteristics of deposits (Figure15).…”

“…In this sense Harbort et al (2011) performed geometallurgical modeling for a porphyry copper-gold deposit located in Peru. Nghipulile et al (2023) studied the effect of mineralogy on the milling of copper oxides and sulfides in a deposit located in Namibia. Harbort et al (2013) applied geometallurgy to estimate comminution attributes in porphyry copper deposits.…”