Density Functional Theory and Atomic Force Microscopy Study of Oleate Functioned on Siderite Surface

• Main Authors: Lixia Li, Chen Zhang, Zhitao Yuan, Haiqing Hao, Chenyang Zhao
• Format: Article
• Language: English
• Published: MDPI AG 2018-01-01
• Series: Minerals
• Subjects: siderite; density functional theory; atomic force microscopy; flotation mechanism; oleate
• Online Access: http://www.mdpi.com/2075-163X/8/1/33

Efficiently discovering the interaction of the collector oleate and siderite is of great significance for understanding the inherent function of siderite weakening hematite reverse flotation. For this purpose, investigation of the adsorption behavior of oleate on siderite surface was performed by density functional theory (DFT) calculations associating with atomic force microscopy (AFM) imaging. The siderite crystal geometry was computationally optimized via convergence tests. Calculated results of the interaction energy and the Mulliken population verified that the collector oleate adsorbed on siderite surface and the covalent bond was established as a result of electrons transferring from O1 atoms (in oleate molecule) to Fe1 atoms (in siderite lattice). Therefore, valence-electrons’ configurations of Fe1 and O1 changed into 3d6.514s0.37 and 2s1.832p4.73 from 3d6.214s0.31 and 2s1.83p4.88 correspondingly. Siderite surfaces with or without oleate functioned were examined with the aid of AFM imaging in PeakForce Tapping mode, and the functioned siderite surface was found to be covered by vesicular membrane matters with the average roughness of 16.4 nm assuring the oleate adsorption. These results contributed to comprehending the interaction of oleate and siderite.