Copper-(Fe)-sulfide ore deposits typically have Cu grades varying from 0.5 to 5%. This equates to approximately 1.5 to 15% sulfide minerals, hence 85 to 98.5% of the remaining ore mass is comprised of gangue minerals. Many of the gangue minerals are relatively benign during mineral processing and subsequent hydrometallurgical and/or pyrometallurgical processing. However, gangue minerals with layered silicate structures (i.e. micas, chlorite, clay minerals) are universally problematic during materials handling due to their propensity to absorb water, easily slime during grinding/milling, depress physical-chemical-thermal separation of ore from gangue minerals, and finally inhibit separation of fluids from residues leading up to final disposal. Acid reactive minerals such as micas, chlorite, carbonates also impact on reagent consumption rates during tank and heap leaching. When developing flow sheets and operating a plant, the impact of each gangue mineral present in the ore needs to be quantified and assessed for each unit of operation within the processing plant.
CITATION:Ehrig, K, Liebezeit, V, Smith, M, Pewkliang, B, Li, Y and Macmillan, E, 2019. Effect of Gangue Mineralogy on Flow Sheet Design and Plant Operation Olympic Dam, in Proceedings MetPlant 2019, pp 1527 (The Australasian Institute of Mining and Metallurgy: Melbourne).