Abstract: To address the difficulty in flotation of smithsonite,this study employed fine sulfur particles as an auxiliary
collector and systematically investigated the flotation behavior of smithsonite in the Na2S-DDA-sulfur system. Combined with
surface characterization techniques including contact angle,Zeta potential,and Fourier-transform infrared spectroscopy (FTIR),
the adsorption and collection mechanism of sulfur on the sulfidized smithsonite surface was explored. The flotation results
show that with the addition of fine sulfur alone,the recovery of smithsonite increased from 28. 46% (with only frother) to
59. 00%. In the Na2S+DDA system,the recovery was 84. 10%,which further increased to 92. 93% after sulfur addition. Mechanism
analysis indicates that fine sulfur particles,characterized by large specific surface area,and abundant reactive sites,effectively
enhance the floatability of smithsonite through their inherent hydrophobicity. Moreover,sulfur adsorbs onto the DDA-coated
sulfidized smithsonite surface via electrostatic interaction,modifies surface roughness,and synergistically strengthens collection
together with DDA and Na2S. Therefore,fine sulfur can serve as an efficient auxiliary collector in the Na2S-DDA system to
significantly improve the flotation recovery of smithsonite.