桥联改性对硅孔雀石表面疏水性的强化效应

Flotation is the primary method to recover chrysocolla. But due to the surface hydrophilicity of chrysocolla is extremely strong and the steric effect of anionic groups around the copper atoms is large, thus, the collector is difficult to form a stable adsorption, which resulting in a poor recovery of chrysocolla. According to the surface properties of chrysocolla, the project proposed the theory model of bridging modification flotation that “macromolecular and polyatomic adsorption - intermediate metal ion bridging - collector adsorb bridging metal ion”. In the project, crystallographic analysis, thermodynamic calculation, kinetics and theoretical calculation were used to determine the mineral crystal characteristics such as lattice constant etc. and copper ions state on the mineral surface. By density functional calculations, combined with x-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), Raman spectroscopy (RS) to study atomic structure of chrysocolla crystal surface, optimize the energy of adsorption reaction between macromolecular reagent and bridging copper ion, and establish the steady state adsorption model of macromolecular reagent and bridging copper ion on the surface of chrysocolla; chrysocolla pure mineral was used as the raw material, and through comparative analysis of the results such as the measurement of collector adsorption capacity before and after surface bridging modified, and Halimond single mineral flotation response, to reveal the hydrophobic evolution law of bridging modification on chrysocolla surface, preliminary establish theoretical model of bridging modification flotation on chrysocolla surface, and provide new ideas for the efficient utilization of chrysocolla.

浮选是回收硅孔雀石的主要方法，但由于硅孔雀石表面亲水性极强，铜原子周围的阴离子基团位阻效应大，捕收剂难以形成稳定的吸附，导致硅孔雀石回收效果差。针对硅孔雀石表面性质的特点，本项目提出“高分子多原子吸附-中间金属离子桥联-捕收剂吸附桥联金属离子”的桥联改性浮选理论模型。项目采用晶体学分析、热力学计算、动力学研究和理论计算，确定矿物晶格常数等晶体特征和表面铜离子的状态；通过密度泛函计算，结合XPS、AFM、RS等研究硅孔雀石晶体表面原子结构，优化高分子药剂与铜离子桥联剂吸附反应的能量，建立高分子药剂与铜离子桥联剂在硅孔雀石表面吸附的稳态模型；以硅孔雀石纯矿物为研究对象，通过表面桥联改性前后捕收剂吸附量测定、Halimond单矿物浮选响应等研究结果对比分析，揭示桥联改性对硅孔雀石表面疏水性的演变规律，初步建立硅孔雀石表面桥联改性浮选的理论模型，为难选硅孔雀石的高效回收提供新的思路。

硅孔雀石表面亲水性强，铜原子周围的阴离子基团位阻效应大，捕收剂难以形成稳定的吸附，导致硅孔雀石回收效果差。针对这一特点，本项目以硅孔雀石为研究对象，通过晶体学分析和理论计算，确定了矿物晶格常数等晶体特征和表面铜离子的状态；计算药剂与铜离子桥联剂在硅孔雀石表面吸附的热力学路径，弄清了药剂与铜离子桥联剂在硅孔雀石表面吸附的动力学影响；明确了桥联改性对硅孔雀石表面疏水性的强化效应的关联因素，探究桥联强化效应微观机制及所反映的表面润湿性演化规律；通过桥联改性前后硅孔雀石表面特性的研究结果比较分析和捕收剂吸附量测定、Halimond 单矿物浮选响应，揭示反映桥联改性对硅孔雀石表面疏水性的演变规律，以及对浮选影响的内在原因。研究结果对硅孔雀石的高效浮选提供新的思路，建立了硅孔雀石表面桥联改性浮选的理论模型。本项目通过DFT理论计算模拟手段构建了硅酸铜晶体模型及药剂在硅酸铜（110）面吸附模型；通过硅孔雀石纯矿物浮选试验验证“多原子吸附-中间金属离子桥联-捕收剂吸附桥联金属离子”桥联改性浮选理论模型；采用Zeta电位、吸附量、SEM-EDS、接触角、ICP-MS、TOF-SIMS、XPS等分析测试手段对桥联改性药剂体系下硅孔雀石表面浮选机理进行分析研究，查清了硅孔雀石表面亲水性强的原因，揭示了硅孔雀石表面与多原子药剂的多点吸附规律研究，揭示了桥联改性前后硅孔雀石表面疏水演变规律，为硅孔雀石浮选高效回收提供了重要理论依据。