Depression mechanism of a novel environment-friendly depressant konjac gum in flotation separation of chalcopyrite and sphalerite

Conventional inorganic depressants are widely used in the flotation separation of chalcopyrite and sphalerite. However, their widespread use entails some inevitable disadvantages, such as environmental hazards, waste generation, and additional costs. In this work, Konjac gum (KG) was investigated as a non-toxic and eco-friendly sphalerite depressant in the flotation separation of chalcopyrite and sphalerite. Micro-flotation and artificial mixed mineral experiments suggested that the addition of KG dramatically depressed the floatability of sphalerite while having a negligible depressive effect on chalcopyrite at pH = 7. Wettability measurements, Zeta potential measurements, adsorption measurements and interaction energy calculations showed that KG have a stronger affinity to sphalerite rather than chalcopyrite, preventing the adsorption of collector on sphalerite surface. FTIR and XPS measurements demonstrated that KG could interact with sphalerite and change the chemical environment of oxygen atoms on sphalerite surface. The Bronsted acid-base interaction, hydrogen bonding, and the attraction between the hydrophobic sections of KG and sphalerite surface were considered as the potential mechanisms in the adsorption of KG on sphalerite.