Sodium Lauroyl Glutamate as a Collector in Cassiterite Flotation

In this paper, sodium lauroyl glutamate (SLG), a stable and inexpensive green surfactant, was used as a flotation collector for the first time in cassiterite flotation. The micro-flotation tests revealed that SLG could effectively collect cassiterite and have superior selectivity against quartz over a wide pH range, compared with benzohydroxamic acid (BHA). The maximum recovery of cassiterite in the presence of SLG was 93.2%, while the quartz recovery was consistently lower than 8%. The adsorption experiments and zeta potential measurements suggested SLG was chemisorbed onto the cassiterite surface. The Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses indicated that the polar groups of SLG anions (the carboxyl and amide groups) chelate with the Sn ions on the cassiterite surface to form five-membered rings. This structure made SLG attach firmly to the cassiterite surface, effectively recovering cassiterite. Lastly, a good flotation index was achieved in the bench-scale flotation tests using SLG as the collector, which confirmed its potential economic value in practical application.