Study of the Influence of the Crystallographic Orientation of Cassiterite Observed with Colloidal Probe Atomic Force Microscopy and its Implications for Hydrophobization by an Anionic Flotation Collector

Abstract

In this study, the physicochemical behaviors of the ( 110), (100), as well as (001) of SnO 2 were investigated by using high-resolution direct force spectroscopy. The measurements were conducted between a silica sphere and sample surfaces in 10 mmol/L KCl between pH 3.1 and 6.2 using colloidal probe atomic force microscopy (cp-AFM-hydrophilic). Dissimilar interactions were detected on different-oriented surfaces. The pH values where the force switched from positive to negative can be clearly distinguished and be ordered as SnO 2 (100) < SnO 2 (001) ≈ SnO 2 (110). By fitting the force curves in the Derjaguin−Landau− Verwey−Overbeck theory framework, anisotropic surface potentials were computed between the three sample surfaces following a similar trend as force interaction. To study the implication of crystallographic orientation to surfactant adsorption, we used Aerosol 22 (sulfosuccinamate) as an anionic collector for cassiterite flotation to functionalize the different samples at pH 3. The contact angle measurements, the topography visualizations by AFM, and the force measurement using cp-AFM with hydrophobized spheres (cp-AFM-hydrophobized) have shown that Aerosol 22 was adsorbed on the sample surfaces inhomogeneously. The adsorption followed the range of SnO 2 (110) > SnO 2 (100) > SnO 2 (001) in the concentration from 1 × 10 −6 to 1 × 10 −4 mol/L.

Insights into the Fracture Nature of Hematite from First Principles DFT Calculations

“…Zhu et al analyzed the reactivity of different crystal planes of spodumene with the help of the D b method. Similar application of the D b method is also reflected in the adsorption behaviors of the anionic collector on the different surfaces of cassiterite studied by Wu et al…”

“…Song et al 16 found that the (112) surface with a smaller broken bond density is more likely to be broken than the (001) surface, thereby explaining the cleavage characteristics and exposed surface properties of wulfenite. Wang et al 17 application of the D b method is also reflected in the adsorption behaviors of the anionic collector on the different surfaces of cassiterite studied by Wu et al 19 Surface energy is another method commonly used to characterize surface reactivity and the surface fracture possibility. 20 It is generally believed that the lower the surface energy, the higher the stability of the crystal face and the greater the fracture probability.…”

Coadsorption of CO and CH4 on the Au doped SnO2 (110) surface: a first principles investigation

“…In our calculations, we choose the most stablest SnO 2 (110) surface as the research surface [60,61], which is modeled by a periodic 3 × 1 plate with 3 layers. To avoid the interaction of adjacent adsorbates, a vacuum layer of 15 Å was added to the SnO 2 model.…”