露天煤矿火烧岩粉尘复合抑尘剂性能表征研究

Performance Characterization of Composite Dust Suppressant for Burning Rock Dust in Open-Pit Coal Mine

为有效解决露天煤矿开放空间采装过程中火烧岩粉尘严重污染的问题,利用羧甲基纤维素钠、氯化镁、柠檬酸和十二烷基苯磺酸钠作为单体材料,研制兼具黏结、吸湿、保湿和润湿功能的复合抑尘剂。采用傅里叶变换红外光谱仪、扫描电镜对抑尘剂进行微观表征,分析抑尘剂的黏结性、保水性、抗蒸发性、抗风蚀性及抑尘效率等性能。结果表明:在保证良好流动性的前提下,复合抑尘剂能有效提高火烧岩粉尘的亲水性和黏结性,能够在粉尘表面形成致密保护膜;25℃条件下,喷洒抑尘剂尘样在56 h时的含水率仍达28%,失水速率缓慢;55℃高温条件下,在16 h时,喷洒抑尘剂尘样的蒸发量约为喷洒水尘样的一半,抗蒸发性能显著;不同风力等级下,在50 min时,喷洒抑尘剂尘样最大风蚀率仅为28%。抑尘效率对比试验表明,研制的复合抑尘剂对全尘、呼吸性粉尘的抑尘效率均优于3种市售抑尘剂,比喷洒水分别对应提高2.3,1.6倍。自主研发的复合抑尘剂能够从岩料本质上改善火烧岩粉尘的理化性质,通过化学基团改性、表面黏结、长效保湿等作用能够有效控制火烧岩粉尘析出,实现采装过程的粉尘源头防治。

In order to effectively solve the problem of serious pollution of burning rock dust in the open space mining and loading process of open-pit coal mine,sodium carboxymethyl cellulose,magnesium chloride,citric acid and sodium dodecyl benzene sulfonate were used as monomer materials to develop a composite dust suppressant with adhesion,moisture absorption,moisture retention and wetting functions.The microstructure of this dust suppressant was characterized by fourier transform infrared spectrometer and scanning electron microscope.The bonding,water retention,evaporation resistance,wind erosion resistance and dust suppression efficiency of the dust suppressant were analyzed.The results show that under the premise of ensuring good fluidity,the composite dust suppressant can effectively improve the hydrophilicity and adhesiveness of the burning rock dust and form a dense protective film on the dust surface.Under the condition of 25℃,the moisture content of the dust sample sprayed with dust suppressant is still 28%at 56 h,and the water loss rate is slow.Under the condition of 55℃high temperature,at 16 h,the evaporation of dust sample sprayed with dust suppressant is about half of that sprayed with water dust,and the evaporation resistance performance is remarkable.Under different wind power levels,the maximum wind erosion rate of dust samples sprayed with dust suppressant is only 28%at 50 min.The comparison test of dust suppression efficiency shows that the dust suppression efficiency of the developed composite dust suppressant for total dust and respirable dust is better than that of three commercially available dust suppressants,which is 2.3 and 1.6 times higher than that of spraying water,respectively.The self-developed composite dust suppressant can essentially improve the physical and chemical properties of burning rock dust.Through chemical group modification,surface bonding,long-term moisturizing and other effects,it can effectively control the precipitation of burning rock dust,realize the prevention and control of dust source in the mining and loading process.