Complexation flotation of boron from the salt lake brine using a novel flotation agent prepared by N-methyl-D-glucamine and 1,2-epoxyoctadecane

A novel boron flotation agent (N-2-hydroxyoctadecyl-N-Methylglucamine, NHO-NMDG) was fabricated using 1,2-epoxyoctadecane and N-methyl-D-glucamine. The obtained collector possesses both collecting and foaming properties and it was characterized by nuclear magnetic resonance, mass spectrometry, Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy methods. The flotation performance for boron removal from the salt lake brine has been studied. The flotation experiments indicated a highly effective removal of boron from the salt lake brine. The boron removal rate in the Da Qaidam brine could reach 67.08% by NHO-NMDG. The mechanism analysis shows that the meglumine group in the bifunctional flotation agent can be complexed with boron, and the long-chain alkyl group can attach to the surface of the bubble and enter into the bubble layer, so as to separate boron from the aqueous solution.