Flotation and Adsorption Studies of Chalcopyrite with 8-Hydroxyquinoline

Flotation tests were conducted in a modified Hallimond tube on chalcopyrite with a collector system of 8-hydroxyquinoline (oxine) and fuel oil. The effects of oxine concentration, pH and conditioning time were studied. The necessity of using fuel oil was established by conducting experiments without fuel oil. Adsorption experiments were carried out in column apparatus under
similar conditions as in flotation but without the addition of fuel oil. The adsorption density of oxine and floatability of chalcopyrite were high both in acidic and basic ranges, where the reagent complexes the metal ions in aqueous solutions. The amount of oxine adsorbed on 1.0 g of the mineral surface was measured at 313°K (40°C) and (along with room temperature data) used to calculate the heat of adsorption, which works out to - 20 KJM-1 indicating that the adsorption reaction is exothermic. The free enersy of oxine adsorption on chalcopvrite, calculated
from the adsorption density data, is approximatelv - 48 KJM-I, indicating the chemisorption. Contact angle measurements reveal the beneficial influence of fuel oil addition. The surface compounds formed were studied by U.V. Visible and Infrared Spectrophotometrv. Results from all the spectral studies confirm that the nature of adsorption is chemisorption and also the formation of
chelating complexes namely, copper and iron oxinates on the mineral surface.