To mitigate the dust dispersion pollution in the open-pit coal mines, this study experimentally develops a novel environmentally friendly coal dust suppressant. The experiment uses naturally biodegradable soybean protein isolate (SPI) as the main material and utilizes anion surfactant sodium dodecyl sulfate (SDS) to modify SPI. In the carboxymethylcellulose sodium and sodium silicate and other auxiliary agents, this process produces gives rise to the SDS-SPI coal dust suppressant. Experimental characterization of the developed dust suppressant reveals that the viscosity of the 5% dust suppressant solution can reach 24.6 mPa s. Correspondingly, the compressive strength reaches 0.48 MPa, and the dust suppression efficiency can reach 93.47% with the presence of force 9 wind. Furthermore, this study uses Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) to analyze the dust suppression mechanism of the developed dust suppressant. It is observed that a layer of compact hardened shell is formed at the surface of the coal powder treated with the newly developed dust suppressant. Also, there exists a strong cementing effect among dust particles, yielding a decent cementing performance. Therefore, the present dust suppressant can effectively suppress dust dispersion in the open-pit coal mines, allowing a mitigation of the environmental pollution.

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The LiV 0.96 Mn 0.04 PO 4 F/C composite was prepared by partial substitution of vanadium with manganese and in situ carbon coating of LiVPO 4 F via a modified carbothermal reduction route. Rietveld refinement of X-ray diffraction (XRD) patterns shows that the crystalline lattice is smaller than the value reported in the literature. While electron energy loss spectroscopy (EELS) on a selected area of high resolution transmission electron microscopy (HRTEM) demonstrates that Mn is successfully doped into LiVPO 4 F, X-ray photoelectron spectroscopy (XPS) indicates the co-existence of Mn 3+ and Mn 4+ . With $6.29 wt% residual carbon (estimated by thermogravimetric analysis, TGA) included, the specific discharge capacity of LiV 0.96 Mn 0.04 PO 4 F/C at 0.1 C and 6 C could reach 138 mA h g À1 and 98 mA h g À1 , respectively. The capacity retention after 1000 cycles at 1 C is about 90%, corresponding to only 0.01% loss per cycle. Electrochemical impedance spectroscopy (EIS) shows that the charge transfer resistance (R ct ) is significantly reduced by Mn substitution, and the lithium diffusion coefficient was calculated to be 1.34 Â 10 À13 cm 2 s À1 , which is an order of magnitude higher than that of pristine LiVPO 4 F/C. Moreover, LiV 0.96 Mn 0.04 PO 4 F/C retains 74% of its initial capacity after 500 cycles at 1 C at 65 C, indicating its potential application at high temperatures.

In view of the fugitive dusts caused by wind disturbance and material handling in coal bunkers, surface plants, and open-air coal stocking yards of coal businesses, the solidifying dust suppressant based on modified chitosan is synthesized and prepared through the chemical modification of-NH 2 with chitosan as a raw material and-NH 2 was replaced by-CH 2 CH(OH)CH 2 N þ (CH 3)CI À through the technique of Fourier transform infrared spectroscopy. According to viscosity experiment results, the viscosity of the modified solidifying dust suppressant increased significantly. The coal particles suppressed by the dust suppressant as observed with a 50,000X scanning electron microscope were coagulated together, which indicated very good cohesion effect. In addition, wind erosion resistance experiment was conducted to analyze the wind erosion rate of coal powders before and after sprayed with the suppressant at different wind speeds, which indicated that the dust suppressant can effectively prevent fugitive dusts at a wind speed of 17 m/s.

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