Comparative study on adsorption and depressant effects of carboxymethyl cellulose and sodium silicate in flotation

Depressant effects of carboxymethyl cellulose (CMC) and sodium silicate on flotation of ilmenite and forsterite using sodium oleate (NaOL) as a collector were investigated by single mineral flotation, zeta-potential, Fourier transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS), and artificially mixed minerals flotation experiments. Single mineral flotation tests indicated that there was significant depressant effect for ilmenite and forsterite in the presence of CMC or sodium silicate, and the selective depressant using sodium silicate was more effective. FT-IR and XPS analysis suggested that CMC and sodium silicate were hardly interacted on the ilmenite surface. For forsterite, CMC adsorbed by hydrogen bonding and weakly chemical adsorption; however, sodium silicate chemically reacted with Mg on the forsterite surface, and made them hydrophilic. The depressant effect of forsterite could be attributed to that CMC and sodium silicate adsorbed on the forsterite surface, which inhibited the approach and adsorption of NaOL to the forsterite surface. (C) 2018 Elsevier B.V. All rights reserved.