洒水控制对钢铁厂原料堆场逸散扬尘的影响

选定中国钢铁公司厂内3种不同的原料堆场(煤料、石料与铁矿),分别就其洒水控制前后进行逸散扬尘的采样分析并探讨其变化。使用滤纸匣采样器吊挂于不同高程来替代一般地面上的总悬浮颗粒物(TSP)高量采样器进行现场采样。结果显示:就原料堆场风蚀作用所致逸散扬尘量而言,洒水后的扬尘控制效率分别为煤料的34.42%、石料的48.62%以及铁矿的66.81%;得知洒水对于风蚀扬尘的控制以铁矿为最佳,其次为石料,而煤料则最低。而物理成分分析结果显示,洒水后煤料所含的黏土含量及含水量均较铁矿与石料为高。另外,由于其喷洒水源使用的是厂内再生水,有可能因再生水的成分造成洒水后的逸散扬尘组成分起到变化。针对再生水与扬尘进行离子成分分析,结果发现洒水后,煤料中水溶性离子浓度有明显上升趋势;石料除了Mg2+及Ca2+浓度变化不大外,其余亦有明显上升的趋势;铁矿则与煤料有类似的情形。证实了喷洒再生水对扬尘中离子浓度的上升产生一定程度的影响。

Effects of Water Spray Control on Fugitive Dusts Originated From Raw Material Piles in Steel Plants

In order to investigate the effects of water spray control, the raw material piles including coal, limestone and iron ore for steel production in China Steel Corporation, Taiwan,were selected and compared for the physicochemical characteristics of fugitive dusts (water-soluble ions,metals,carbons and silt). The results from this study indicated that the water spray control could reduce 34.42% ,48.62% and 66.81% of the fugitive dusts emitted from coal, limestone and iron ore piles,respectively,owing to wind erosion. Moreover,the results from the physical characteristics of raw materials indicated that both the silt and water content of coal after water spray was generally higher than iron and limestone. On the other hand, the results from the chemical composition of raw materials indicated that most of the water soluble ions in coal increased concentrations significantly after water spray, with the highest concentration of NO3-for anions and the highest concentration of Na+ for cations. Limestone and iron ore had a similar tendency as coal,suggesting that spraying of the recycled water on these piles indeed effected the chemical composition of raw materials.