1-羟基-2-甲基-2-烯辛基膦酸对锡石的浮选行为及吸附机理

摘要

The flotation behavior and adsorption mechanism of novel (1-hydroxy-2-methyl-2-octenyl) phosphonic acid (HEPA) to cassiterite were investigated by micro-flotation tests, zeta potential measurements, FTIR determination and density functional theory (DFT) calculation. The flotation results demonstrated that HEPA exhibited superior collecting performance compared with styrene phosphonic acid (SPA). The cassiterite recovery maintained above 90% over a wide pH range of 2−9 with 50 mg/L HEPA. The results of zeta potential measurement and FTIR detection indicated that the adsorption of HEPA onto cassiterite was mainly attributed to the chemisorption between HEPA monoanions and Sn species on mineral surfaces. The DFT calculation results demonstrated that HEPA monoanions owned higher HOMO energy and exhibited a better affinity to cassiterite than SPA, which provided very clear evidence for the stronger collecting power of HEPA presented in floatation test and zeta potential measurement.%采用纯矿物浮选实验、动电位测试、红外光谱检测以及密度泛函理论计算研究了1-羟基-2-甲基-2-烯辛基膦酸(HEPA)对锡石的浮选行为及吸附机理。浮选实验结果表明，相比苯乙烯膦酸(SPA)，HEPA具有出更强的捕收性能。当HEPA浓度为50 mg/L时，在pH 2−9范围内锡石回收率都保持在90%以上。动电位测试和红外光谱检测结果表明，HEPA在锡石表面的吸附主要是通过HEPA单阴离子与锡石表面的锡原子形成化学吸附。密度泛函计算结果表明，HEPA单阴离子比SPA单阴离子具有更高的HOMO能量和对锡石更强的吸附力，这为浮选实验和动电位测试中HEPA的更强捕收力提供了有力证明。