Investigations on the reverse flotation of quartz from hematite using carboxymethyl chitosan as a depressant

Depressant carboxymethyl chitosan (CMCS) was introduced to reverse flotation of quartz from hematite using collector DDA. Microflotation experiments presented that CMCS completely depressed the hematite flotation while it had little effect on quartz flotation. The mineral mixture flotation confirmed the reagent scheme of DDA/CMCS could achieve efficient separation of quartz from hematite. It was also found that CMCS has better selective depression ability than the widely-used starch . Zeta potential measurements illustrated that CMCS could prevent DDA adsorption onto the hematite surface, while it did not affect the interaction between DDA and quartz surface. X-ray photoelectron spectroscopy (XPS) indicated that CMCS interacted with the Fe(III) components of hematite by chemisorption , which was stronger than the bonding between starch and hematite. Molecular dynamics simulation (MDS) further revealed the twice interaction energy of CMCS with (001) hematite surface than that of starch. Hence, CMCS has the potential to replace starch in practice.