Abstract
To solve the problem that the iron-bearing silicate gangue aegirite is difficult to separate because of its own density, specific magnetization coefficient and mineral surface properties similar to those of iron oxide. The effect of thiosalicylic acid（TSA） on the floatability of specularite and aegirite under the condition of sodium oleate（NaOL） as collector was investigated by flotation test, and the depression mechanism of TSA on aegirite was studied by infrared spectroscopy（FTIR）, adsorption tests, Zeta potential detection, XPS analyses and Boltzmann theory analysis. The results show that TSA has a significant depression effect on aegirite and almost no depression effect on specularite. TSA mainly adsorbes on the surface of aegirite, resulting in a leftward shift of the iso-electric point of aegirite from 3.3 to 1.0, while it adsorbes less on the surface of specularite and its iso-electric point changes weakly. The -SH group in TSA combines with metal ions on the surface of aegirite to form metal complexes during the adsorption process, and the hydrophilic group -COOH increases the hydrophilicity of aegirite, which widenes the hydrophilic difference between aegirite and specularite, and achieves the selective depression effect on aegirite.