Advances in depressants for flotation separation of Cu–Fe sulfide minerals at low alkalinity: A critical review

The flotation separation of Cu–Fe sulfide minerals at low alkalinity can be achieved using selective depressants. In the flotation system of Cu–Fe sulfide minerals, depressants usually preferentially interact with the pyrite surface to render the mineral surface hydrophilic and hinder collector adsorption. This study summarizes advances in depressants for the flotation separation of Cu–Fe sulfide minerals at low alkalinity. These include inorganic depressants (oxidants and sulfur-oxygen compounds), natural polysaccharides (starch, dextrin, konjac glucomannan, and galactomannan), modified polymers (carboxymethyl cellulose, polyacrylamide, lignosulfonate, and tricarboxylate sodium starch), organic acids (polyglutamic acid, sodium humate, tannic acid, pyrogallic acid, salicylic acid, and lactic acid), sodium dimethyl dithiocarbamate, and diethylenetriamine. The potential application of specific inorganic and organic depressants in the flotation separation of Cu–Fe sulfide minerals with low alkalinity is reviewed. This paper comprehensively discusses advances in the use of organic depressants in the flotation separation of Cu–Fe sulfide minerals and summarizes the depression performance and mechanism of different types of organic depressants on mineral surfaces. Finally, perspectives on depressants in the flotation separation of Cu–Fe sulfide minerals at low alkalinity are proposed.