基于密度泛函理论计算对捕收剂在烧绿石表面的吸附行为差异研究

通过密度泛函理论计算和浮选实验研究了烧绿石晶体性质以及三种捕收剂在其表面的吸附行为差异。计算和 XPS 分析结果显示：烧绿石晶体中 Nb 和 Ca 的强反应活性和解离面的不稳定性使得捕收剂与其结合而产生浮选作用，BHA 和 DDA 主要通过脱质子化和非脱质子化官能团在烧绿石表面吸附，吸附活性位点为 Nb，因而其具有较强的捕收性和选择性，而 NaOl 主要通过 RCOO-和烧绿石表面的 Ca 相互作用而产生化学吸附，吸附能较小，故其捕收性和选择性最差。验证实验表明，在适宜的浮选条件下，DDA的浮选效果最好，回收率可达 89%，受 pH 影响较大，BHA 和 NaOl 捕收性能略差，但作用稳定，浮选指标能够保持在较高水平。

Study on the difference of adsorption behavior of collectors on the surface of pyrochlore based on DFT calculation

In this work, the difference of adsorption behavior of three collectors on pyrochlore surface were studied by DFT and flotation experiment to provide theoretical support for selecting more efficient collectors. The results of calculation and XPS analysis show that the strong reactivity of Nb and Ca in the pyrochlore crystals and the instability of the dissociation surface enable collector to combine with it to produce flotation effect. BHA and DDA adsorbed on pyrochlore surface mainly through deprotonated and non deprotonated functional groups, the adsorption active site was Nb, so they have strong collection andselectivity, while NaOl was chemisorption mainly through the interaction of RCOO- and Ca on pyrochlore surface, so its collection and selectivity are the worst. The verification experiment shows that under the suitable flotation conditions, DDA has the best flotation effect and the recovery rate can reach 89%, and BHA and NaOl is slightly worse.