Copper Geometallurgy Programs: Comparison Between Different Deposit Types

Geometallurgy is a multidisciplinary program that allows for exploration and mining projects to de-risk and increase value of their deposit. This paper will discuss the application of geometallurgical methodology by comparing two settings of copper mineralogy and metallurgy that have the same goal: understanding and modeling copper metallurgical grade and recovery within a mine plan for a prefeasibility study. The first setting is a copper-rich magmatic sulfide deposit from the Midcontinent Rift, Minnesota, USA. This deposit is an intercontinental setting, has simple geomechanics, and is comprised of relatively fresh mafic–ultramafic rocks that contain critical metals. The metallurgy and tailings management options are relatively straightforward. The second setting is a copper porphyry deposit from Arizona, USA. Porphyry deposits are contained within felsic rock types with extensive alteration profiles. Recent tectonics creates complicated geomechanical considerations that affect mine planning and water management. The extraction potential of the supergene-hypogene model affects mineral processing and tailings management. The overall framework of the geometallurgy programs will be the same at the highest level: choose samples, perform standardized testwork, analyze and model data, then domain the deposit and scale-up. However, project location and ore type dictate the internal methodology and analysis details. This results in optimized metallurgical decisions and a more adaptable mine plan that increase confidence in copper grade and recovery predictions.