(1. 北京科技大學土木與環(huán)境工程學院，北京 100083；
2. 北京科技大學工業(yè)典型污染物資源化處理北京市重點實驗室，北京100083)
摘 要: 以廣西某典型錫尾礦為對象，重點研究不同模擬酸雨pH值(3.0，4.5，6.0)條件下尾礦中特征重金屬As、Zn、Pb的釋放規(guī)律。結果表明：As、Zn、Pb累積釋放量、淋溶強度及淋出液電導率與模擬酸雨pH值呈負相關，而淋出液pH值與模擬酸雨pH值呈正相關。在尾礦淋溶過程中，淋出液的pH值呈先急速上升后快速下降最后緩慢增長的趨勢，電導率保持持續(xù)增長；重金屬As、Zn、Pb的釋放過程分為3個階段，且淋溶強度由大到小的順序依次為Pb、Zn、As。XRD分析表明：淋溶后尾礦中主要礦物石英、方解石及磷鐵鋁礦衍射峰的強度明顯減弱，且模擬酸雨pH值越低，強度減弱越明顯。SEM-EDS分析發(fā)現(xiàn)，尾礦經(jīng)淋溶后表面變得不平整，出現(xiàn)大量孔洞和硅酸鈣顆粒物，隨著淋溶時間延長，F(xiàn)e、S、As、Zn、Pb的含量明顯減少。
關鍵字: 錫尾礦；模擬酸雨；重金屬；釋放規(guī)律
（1. School of Civil and Environmental Engineering,
University of Science and Technology Beijing,Beijing100083, China;
2. Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants,
University of Science and Technology Beijing, Beijing 100083, China）
Abstract:Leaching experiments of a Guangxi typical tin tailings under simulated acid rain (pH=3, 4.5, 6.0) were carried out to investigate the release law of As, Zn and Pb. The results indicate that the pH of leaching liquid is positively correlated to the pH of simulated acid rain, while the conductivities, the accumulated leaching liquid concentrations of As, Zn and Pb and leaching intensity are negative correlated. The pH of leaching liquid increases at first, and then decreases frequently, and last it keeps increasing gradually. The conductivitieskeep steady growth and the releasing characteristic of As, Zn and Pb is similar in the leaching process. It can be divided into three stages. The leaching intensity from big to small is Pb, Zn and As. The main difference with the XRD pattern of tailings decreases obviously in the relative height of peak of main mineral, such as quartz, calcite and paravauxite.The pH of the acid rain islower,the decrease of the height is more significant. The results of SEM analysis show that the surface of leaching residue becomes rough which appears lots of holes and precipitation. The EDS analysis indicates that the precipitation adhered to the leaching residue surface is CaSiO3, and with time prolonging, the contents of Fe, S, As, Zn, Pb reduce significantly.
Key words: tin tailing; simulated acid rain; heavy metal; leaching characteristic
