Activation effect of lead ions on scheelite flotation: Adsorption mechanism, AFM imaging and adsorption model
Activation effect of lead ions on scheelite flotation: Adsorption mechanism, AFM imaging and adsorption model
复制标题
铅离子对白钨矿浮选的活化作用：吸附机理、AFM成像和吸附模型
DOI：
10.1016/j.seppur.2018.09.051
复制
发表时间：
2019-01-31
影响因子：
8.6
通讯作者：
Jia, Wenhao
中科院分区：
文献类型：
--
作者：
Dong, Liuyang;Jiao, Fen;Jia, Wenhao
This paper systematically studied the effect of lead ions on floatability of scheelite under sodium oleate (NaOL) system, and the deep adsorption mechanism was revealed by a series of mechanism experiments and the adsorption morphology of NaOL was observed by atomic force microscope (AFM). Micro-flotation test indicated that the floatability of scheelite increased sharply from 47.25% to 80.12% in the presence of lead ions at pH 7. Zeta potential results revealed the positively charged lead ions species (Pb2+ and PbOH+) positively changed the zeta potential of scheelite, which favored the adsorption of negatively charged NaOL species (RCOO-, RCOOH.RCOO- etc.). XPS and FTIR analysis confirmed that NaOL was chemisorbed on scheelite surface and the adsorption was more severe in the presence of lead ions. Lead ions were chemisorbed on scheelite surface in the form of W-O-Pb2+, which facilitated the further adsorption of NaOL. This increased the active sites on scheelite surface for NaOL adsorption. AFM images intuitively showed the presence of lead ions increased the adsorption coverage of NaOL but did not affect the thickness of the adsorption layer. The adsorption thickness was still 6 nm-7 nm and the adsorption was multilayer adsorption. Based on these studies, an adsorption model was finally obtained.
