Study on the synergistic effect of sodium oleate/salicylaldoxime mixed collector co-adsorption on cassiterite flotation

Cassiterite, a vital source of tin, is commonly separated via flotation. This study presented a mixed collector comprising sodium oleate (NaOL) and salicylaldoxime (SAOX) for cassiterite flotation. Micro-flotation experiments showed that the recovery of cassiterite increased to above 90 % upon adding mixed NaOL/SAOX collectors under the concentration of 0.6*10⁻⁴ mol L⁻¹ with a molar ratio of 1:3 at pH 7. The classical first-order model offered the most suitable fit for the experimental data. It exhibited fast-floating behavior as the k value of cassiterite increases to 1.77 under the mixed collector system. Zeta potential measurements revealed that both NaOL and SAOX could adsorb onto the cassiterite surface. The mixed collector NaOL/SAOX leads to a significant change in the zeta potential of cassiterite, indicating that this mixed collector may interact with the surface of cassiterite. Contact angle measurements indicated that the mixed collector increased the contact angle of cassiterite, thereby enhancing its hydrophobicity. FTIR analysis revealed the chemical adsorption and synergistic effect of the mixed collectors on the cassiterite surface. XPS analysis further confirmed this synergism on the cassiterite surface. Overall, this paper introduces a mixed collector for cassiterite flotation, elucidates the synergistic adsorption mechanism of NaOL and SAOX on the cassiterite surface, and provides a new approach for improving the flotation efficiency of cassiterite.