Construction of Molecular Model and Adsorption of Collectors on Bulianta Coal

Abstract

To study the effects of different oxygen functional groups on the quality of flotation clean low-rank coal, two kinds of collectors with different oxygen-containing functional groups, methyl laurate, and dodecanol, were selected and their flotation behaviors were investigated. The Bulianta coal was the typical sub-bituminous coal in China, and the coal molecular model of which was constructed based on proximate analysis, ultimate analysis, 13C-NMR, and XPS. The chemical structure model of the coal molecule was optimized, and the periodic boundary condition was added via the method of molecular dynamics methods. The different combined systems formed by collectors, water, and a model surface of Bulianta coal have been studied using molecular dynamics simulation. The simulation results of dodecanol and methyl laurate on the surface of Bulianta coal show that dodecanol molecules are not evenly adsorbed on the surface of coal, and have higher adsorption capacity near carboxyl and hydroxyl groups, but less adsorption capacity near carbonyl and ether bonds. Methyl laurate can completely cover the oxygen-containing functional groups on the coal surface. Compared with dodecanol, methyl laurate can effectively improve the hydrophobicity of the Bulianta coal surface, which is consistent with the results of the XPS test and the flotation test.

Microscopic Diffusion Characteristics of Linear Alkylbenzene Sulfonates on the Surface of Anthracite: The Influence of Different Attachment Sites of Benzene Ring in the Backbone

“…Through the Amorphous Cell module of Materials Studio 6.0, 40 optimized coal molecules (ratio 1:1) were randomly packed in a cubic simulation cell 35 × 35 × 35 Å 3 (X Y Z) to obtain a lowdensity three-dimensional structure model. Then 300 ps molecular dynamics simulations were performed to adjust the crystal cell structure continuously using the NVT ensemble (the constant-temperature, constant-volume ensemble) and NPT ensemble (the constanttemperature, constant-pressure ensemble), so that the density of coal molecular structure reached a balance [30], as shown in Figure 3. The final 3D coal structure model is shown in Figure 2b.…”

“…However, the experimental me structure, dynamics, and energy characteristics of the molecula the coal surface. Molecular dynamics (MD) simulation can expla tics [29][30][31][32].…”

“…Through computer simulation, the microstructure and macr surfactant system can be linked. In particular, MD simulation useful tool for studying the structure and dynamics of surfactan At present, a large number of MD simulation studies have been sion of other surfactants on the surface of coal [29][30][31], but ther diffusion characteristics of LAS on the surface of coal [20,24].…”

“…In particular, MD simulation has proven to be a very useful tool for studying the structure and dynamics of surfactants at the molecular level. At present, a large number of MD simulation studies have been conducted on the diffusion of other surfactants on the surface of coal [29][30][31], but there are few studies on the diffusion characteristics of LAS on the surface of coal [20,24].…”

Computational Study on the Microscopic Adsorption Characteristics of Linear Alkylbenzene Sulfonates with Different Chain Lengths on Anthracite Surface

“…Surfactants have been widely used in the coal industry, such as in the fields of coal flotation and coal dust suppression [34][35][36][37][38][39][40][41]. e research on the interface characteristics of coal relies on the basic theory of coal wettability [42][43][44]. A large number of experimental studies have shown that the surface active agent diffusion characteristics on the coal surface determine the wetting effect of coal [45][46][47][48][49][50].…”