Enhancing chalcopyrite flotation by tackling hydrophobic silicate gangue

The Khetri Copper concentrator of M/s Hindustan Copper Limited, encountered with the problem of voluminous black froth, while treating copper ore from Banwas mine. The copper concentrate of the plant assayed 16.19% Cu, and 19.57% Acid insoluble with ~89% Cu recovery. Mineralogical studies revealed that the plant concentrate consists of ~45% chalcopyrite, 10–15% quartz, ~5% mica, 15–20% amphibole, 10–15% pyrite and pyrrhotite, 2–3% magnetite and ~5% other minerals. In order to find a solution to the black froth problem, and to improve the Cu grade and recovery, ROM copper ore sample from Banwas mine was sent to RODL, IBM, Ajmer by M/s HCL, Khetri. Bench scale flotation studies carried out at plant grind of 65.9% < 75 μm, under optimized reagent dosage, at dilute pulp density yielded a II cleaner concentrate assaying 28.81% Cu, 7% acid insoluble with 92.4% Cu recovery. The wt% yield was 6.0. The grade and recovery achieved is much better than that was stipulated by M/s. HCL, Khetri. The study revealed that it is possible to control silicate gangue minerals by slight modifications of the flotation parameters under the existing plant practice conditions.