Effective separation of specularite and aegirite using chitosan as a novel depressant

Abstract

As a typical iron-bearing silicate gangue, aegirite often associates with specularite. Due to the iron element contained in aegirite, it has similar surface properties to specularite. Flotation is by far one of the most efficient methods of processing this kind of iron ore. But the traditional depressants unable to take action in the separation of specularite and aegirite. Chitosan was used as a novel depressant to attempt to separate specularite from aegirite through microflotation tests, adsorption tests, contact angle measurements, Zeta potential measurements, and XPS analysis. The flotation results indicate that chitosan show more strong depression effect on specularite than aegirite. Zeta potential measurements, contact angle measurements and adsorption tests demonstrate that chitosan is more inclined to adsorb on the specularite surface than aegirite, which hinders the subsequent adsorption of collector sodium oleate and increases difference in hydrophobicity between the two minerals. The XPS results of specularite validate the adsorption of chitosan on specularite, and illustrate that electrons of chitosan were partially transferred to oxygen and iron atoms in specularite during the adsorption process.