Synergistic mechanism of acidified water glass and carboxymethyl cellulose in flotation of nickel sulfide ore

Abstract

• The effect mechanisms of serpentine and talc on sulfide flotation are different. • Acidified water glass can eliminate heterocoagulation between serpentine and talc. • Carboxymethyl cellulose can inhibit talc flotation . • When serpentine and talc coexist, dispersants and inhibitors need to be used together. Efficiently utilizing nickel sulfide ores containing multiple magnesium silicate gangue minerals through flotation is difficult. Therefore, in this study, we investigated the flotation behavior and discussed the mechanism of a refractory nickel sulfide ore with multiple MgO gangue minerals. The synergistic mechanism of acidified water glass (AWG) and carboxymethyl cellulose (CMC) in the flotation of the nickel sulfide ore was studied through flotation tests, zeta potential measurements, adsorption capacity tests, Fourier transform infrared ray (FTIR) spectroscopy, and observation under a microscope. The results showed that the addition of AWG could change the electrical properties on the surface of serpentine, weaken the heterogeneous aggregation of serpentine and talc, and increase the selective adsorption of CMC on the talc surface. The actual ore flotation test was conducted with the synergistic effect of AWG and CMC. In the practical flotation test of the ore, the concentration of MgO in the concentrate, compared with the original process with CMC alone, was reduced from 9.62% to lesser than 5.92%, with the combined synergistic action of acidified sodium silicate and CMC acting as the depressant. Simultaneously, the grade and recovery of Ni from the Ni-mixed concentrate remained unchanged, and the inhibiting effect of the magnesium-bearing gangue minerals improved.