【摘要】 宁夏贺兰山煤炭开采和煤层自燃已有300多年历史,该区近30年来开采强度加大,自燃程度趋重。本工作深入调查和系统测试了该区地表土和牧草等共计137件样品中的氟含量,结果显示:地表土中氟含量总均值为707±126μg/g,显著高于当地氟背景值;牧草氟含量为218±42μg/g,表明羊氟中毒可能与地表土及牧草高氟息息相关。地表土中硫酸盐均值为1771±130μg/g,而p H均值为5. 92±0. 82,与当地背景值相比,该区硫酸盐含量显著偏高,酸性明显较强。研究表明,贺兰山北段地表土存在酸污染及硫酸盐污染,并伴随氟污染,可能源于该区域采煤、用煤及煤层自燃历史悠久,导致氟化物、酸性硫酸盐沉降并存,随之污染牧草,进而引发羊氟中毒。更多还原

【Abstract】 There is a history of 300 years of coal mining and coal seam fire in the Helan Mountain,Ningxia province. The coal mining and spontaneous combustion kept increasing for nearly 30 years and the endemic sheep fluorosis aggravated. A total of 137 samples including topsoil and grass were collected in this area and their fluorine levels were determined. The mean content of fluorine in topsoil samples was 707±126 μg/g（ n = 77） and the mean fluorine content of grass was 218±42 μg/g（ n = 28）,significantly higher than respective background values of the region,suggesting that the sheep fluorosis may be associated with high fluorine contents in topsoil and grass; the sulfate content and p H of topsoil were 1 771±130 μg/g（ n = 77） and 5. 92±0. 82（ n = 77）,respectively,and positively correlated in acidic topsoil samples（ r = 0. 72）,indicating that the acidity of soil may result from acidic sulfates,such as NaHSO₄ and KHSO₄. The high fluorine,sulfate and acidity in soil may because of the long history of coal mining,coal using and coal spontaneous combustion,which result in fluoride and acidic sulfate coexisting depositions.更多还原