常规卤化物和高分子材料抑制尾矿库扬尘的试验

Control of dust from tailings pond using conventional halides and polymer materials

  • 摘要: 选取溶液质量浓度、溶液喷洒量以及外部风速作为变量,通过室内试验考察了常规卤化物和高分子材料对扬尘控制的效果。以抗风蚀能力和结壳抗破坏能力为响应变量。结果表明,随着抑尘剂浓度的增加和喷洒量的增加,结壳的抗风蚀性和抗破坏性可以得到提高。在卤化物溶液中,CaCl2的抑尘性能最好。在风速为7.5 m·s−1的条件下,CaCl2喷洒量为4.5 L·m−2,且其质量浓度为50 g·L−1时,尾矿质量损失量为0.75 g·m−2·min−1,贯入阻力为466 kPa。在高分子材料中,聚丙烯酰胺的抑尘效果最好。在风速为7.5 m·s−1的条件下,聚丙烯酰胺喷洒量为4.5 L·m−2,且其质量浓度为0.5 g·L−1时,尾矿质量损失量为0.30 g·m−2·min−1,贯入阻力为248 kPa。抑尘剂的选取可根据当地年均风速确定,年均风速较大时,可选择聚丙烯酰胺作为尾矿库抑尘剂,反之则可选择CaCl2为尾矿库抑尘剂。

     

    Abstract: Mine tailings, the byproducts of mineral processing, are special solid wastes generally classified as loose sandy silts or silty sands that are vulnerable to wind erosion, especially in arid and semiarid regions. Mine tailings also contain potentially toxic elements such as Cd, Cr, Mn, Ni, Zn, Pb, and As. Thus, fugitive dust from mine tailings is associated with a number of environmental and safety concerns. In recent years, dust control has become a hot topic in the environmental management of tailings storage facilities. Using the response variables of wind erosion resistance and penetration resistance, the experimental variables of the solution concentration, spray amount, and external air speed, laboratory tests were conducted to investigate the effects of conventional halides and polymer materials on dust control. The results indicate that the wind erosion resistance and penetration resistance of the crust can be improved with increase in the concentration of the dust-depressor and the amount of spray used. In the halide solution, CaCl2 exhibited the best dust control effect. When the wind speed is 7.5 m·s−1 and the spraying amount of CaCl2 is 4.5 L·m−2 at a concentration of 50 g·L−1, the loss quantity of tailings is 0.75 g·m−2·min−1 and the penetration resistance is 466 kPa. Among the polymer materials, polyacrylamide exhibits the best dust control effect. The loss quantity of tailings is 0.30 g·m−2·min−1 and the penetration resistance is 248 kPa when the wind speed is 7.5 m·s−1 and the spraying amount of polyacrylamide is 4.5 L·m−2 at a concentration of 0.5 g·L−1. This paper emphasizes that the selection of dust-depressor can be determined based on the local annual mean wind speed, whereby polyacrylamide should be selected as the dust suppressant for a tailings pond when the annual mean wind speed is high. Otherwise, CaCl2 should be selected as the dust-depressor for a tailings pond.

     

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