十二胺和十二烷基磺酸钠在长石石英表面的吸附

Adsorption of Dodecyl Amine and Sodium Dodecyl Sulfonate on Feldspar and Quartz

采用浮选试验、ζ-电位和FTIR光谱分析,研究了十二胺(阳离子捕收剂,DDA)和十二烷基磺酸钠(阴离子捕收剂,SDS)作捕收剂在长石石英表面的吸附。浮选结果表明,pH值在2附近时,长石和石英的浮游差最大,混合捕收剂能增大二者的浮游差,有利于长石的优先浮选。在单一捕收剂中长石和石英ζ-电位均整体向正或负方向移动,在混合捕收剂溶液中,二者ζ-电位在碱性介质中正移幅度较酸性介质明显。FTIR光谱结果表明,pH值为2时,DDA在长石和石英表面均只存在物理吸附;SDS在长石表面既存在物理吸附,还与Al-O形成化学吸附,而在石英表面仅存在物理吸附;混合捕收剂在长石表面既有物理吸附,还存在氢键作用,而在石英表面仅存在物理吸附。

The adsorption of dodecyl amine （ DDA, cationic collector ） and sodium dodecyl sulfonate （SDS, anionic collector ） on feldspar and quartz have been studied through flotation tests, zeta potential and FTIR spectra. According to the analysis of flotation tests, there has the most significant floatability difference when the pH value is about 2, and mixed collector is beneficial to the selective flotation of feldspar. The zeta potential tests indicate that the potentiodynamic of mineral surface integrally shifts to positive direction in cationic collector, while it moves to negative direction in anionic collector, when compared with acid medium, the potential value obviously shift to positive direction in alkaline medium. The FTIR spectroscopy results under condition of pH=2 show that dodecyl amine in the surface of feldspar and quartz both have only physical adsorption, and sodium dodccy1 sulfonate has physical adsorption as well as chemical adsorption in feldspar by aluminium-oxygen bond, while it just has physical adsorption in quartz. There are physical adsorption and hydrogen bonding between the surface of feldspar and mixed collector, and only physical adsorption between quartz and mixed collector.