Surface characteristics,collector adsorption,and flotation response of covellite in oxidizing environment

The surface characteristics, collector adsorption, and flotation response of covellite in the presence of NaClO and FeCl₃ were investigated using micro-flotation tests, X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (TOF-SIMS), and contact angle measurements. The micro-flotation test results indicated that covellite was effectively inhibited by the presence of NaClO and FeCl₃. However, the dosages of these depressants were large, and the conditioning time was long. The results of the XPS and TOF-SIMS analyses indicated that NaClO could oxidize the covellite surface and reduce the active sites of Cu. Oxidation products, including CuO and Cu(OH)₂, were generated on the covellite surface. After the addition of FeCl₃, the precipitation of iron hydroxide on the covellite surface increased the content of hydrophilic species on the mineral surface. Thus, the adsorption of ammonium dibutyl dithiophosphate on covellite surface was prevented, which reduced the floatability of the covellite.