摘要
Wollastonite and calcite were both calcium-containing phases possessing remarkably analogous surface physical-chemical characteristics. Conventional primary amine collectors exhibit poor selectivity between the two, making separation difficult. In this experiment, the quaternary ammonium salt octadecyltrimethylammonium chloride (STAC) was employed as a novel collector to achieve efficient separation of wollastonite and calcite. Flotation experiments on both single and mixed minerals demonstrated that efficient separation of wollastonite and calcite could be achieved under conditions of 20 mg/L STAC and pH 7.0. Zeta potential and contact angle measurements showed that, following interaction with STAC, the zeta potential and contact angle of wollastonite increased significantly; Fourier-transform infrared (FTIR) analysis revealed that, after adsorption of STAC onto wollastonite, new absorption peaks appeared at 2922.88 cm −1 and 2854.06 cm −1 , whilst no significant changes were observed in calcite; Field-emission scanning electron microscopy (FESEM) revealed that the collector STAC significantly altered the surface microtopography of wollastonite upon adsorption. Based on the data regarding the increase in nitrogen content, STAC appears to prefer adsorption onto the surface of wollastonite; XPS analysis revealed that after STAC treatment, the O1s binding energy shift on wollastonite was 1.10 eV, which is approximately 22 times the shift observed on calcite (0.05 eV), suggesting substantially stronger interaction between STAC and wollastonite; Finally, molecular dynamics simulations further elucidated that STAC undergoes oriented adsorption on the wollastonite surface via strong electrostatic anchoring, whereas only transient non-covalent interactions occur on calcite. In summary, STAC is a highly promising flotation collector capable of efficiently separating wollastonite from calcite.
危险品化学品经营许可证（带存储）