Selective flotation separation of spodumene from feldspar using a novel mixed anionic/cationic collector NaOL/ND13

The mixed anionic/cationic collector sodium oleate/ N-lauryl-1, 3-propylene diamine (NaOL/ND13) was firstly used to separate spodumene from feldspar and exhibited high selectivity. The flotation experiments of single and artificial-mixed mineral showed that the mixed NaOL/ND13 (NaOL: ND13 = 5:1) exhibited excellent flotation separation performance for spodumene from feldspar at pH 8.0. The zeta potential measurement results showed that NaOL and ND13 adsorbed on the mineral surface through chemical and electrostatic adsorption, respec-tively. The FTIR measurement results showed that the dominant species of NaOL/ND13 adsorbed strongly on mineral surface than each of its components and the interaction between collector and spodumene surface was stronger than that of feldspar surface. Contact angle measurements showed the mixed NaOL/ND13 amplified the difference in surface hydrophobicity between spodumene and feldspar. Ultra-microcalorimetric measurements showed the greater the absolute values of the net reaction heat for spodumene and feldspar reacted with col-lectors, the better their flotation separability. XPS further showed that NaOL/ND13 had strong chemical reaction with Al sites on mineral surface, but the interaction of NaOL/ND13 with spodumene was stronger than that with feldspar. Therefore, the results of this study are expected to provide more reference value and a meaningful guide for the development of selective flotation collectors for spodumene and feldspar.