陕北矿区煤矸石淋滤试验研究

露天堆积的煤矸石遭雨淋滤后易污染环境。以陕北矿区煤矸石为研究对象，利用自主研制淋滤仪器，模拟降雨工况，尝试不同降雨强度及矸石粒径条件下淋滤试验，结果表明:淋滤液电导率随时间表现为“快降—缓降—趋稳波动”3个阶段，Cr浓度随时间表现为“快降—缓降（或趋稳波动）”2个阶段；降雨强度增大68%时，大、小粒径组的电导率平均值分别降低18.9%、24.6%，Cr浓度平均值分别降低18.8%、22.0%；平均粒径增大50%时，大、小雨强组的电导率平均值分别降低4.0%、10.7%，Cr浓度平均值分别增大34.5%、29.2%。主要结论:矸石可溶元素释放呈指数衰减规律，雨强对可溶元素整体淋出水平更为敏感；Cr淋出过程与其他可溶物相似，遵循淋出浓度分段降低逐渐趋稳的规律，粒径对Cr淋出水平更为敏感；矸石风化面较新鲜面更早达到Cr释放峰值，导致淋滤后期浓度波动；可溶元素的整体释放水平决定于试样总表面积，但Cr主要由矸石风化表面淋出。 

Coal gangue leaching experiment of mining area in Northern Shaanxi

The coal gangue of northern Shaanxi is set as the research object, a self-developed leaching instrument was used to simulate rainfall conditions, leaching experiments were attempted under different rainfall intensity and different grain size of gangue. The results are as follow:the leachate conductivity shows three stages, that is fast decline, slow decline and stable fluctuation with test time, the Cr concentration shows two stages:fast decline and slow decline (or stable fluctuation) with test time; With the increase of rainfall intensity by 68%, the mean conductivity in large and small particle size groups are decreased by 18.9%, 24.6%, the Cr mean concentration are decreased by 18.8% and 22.0%; With the increase of mean particle size by 50%, the mean conductivity in large and small rainfall intensity groups are decreased by 4.0% and 10.7%, the Cr mean concentration are increased by 34.5% and 29.2%. The conclusions are:the release of soluble elements in gangue shows a law of exponential decay, rainfall intensity is more sensitive to the release of soluble elements; Cr leaching process is similar to other soluble substances which follows the law that concentration decreases in several stages and stabilizes gradually, particle size is more sensitive to the release of Cr; Cr leaching concentration peak appears earlier in weathered surface than fresh surface, which makes concentration fluctuation in later stage of leaching; The overall release level of soluble element depends on the total sample surface area, but Cr mainly releases through weathered surface of gangue.