淮南煤田石炭-二叠系煤中有害元素分布与富集赋存特征

为调查分析淮南煤田石炭—二叠系有害元素的分布与富集赋存特征,采用ICP-MS对张集矿、潘三矿和顾桥矿共159件样品的煤中微量元素含量进行了测试分析,分析了11种有害元素的含量分布特征、富集特征,利用聚类图谱探讨了有害元素的富集赋存特征。研究结果表明:除As外,绝大多数元素的平均含量均低于地壳丰度,除Ba和As外,绝大多数元素的平均含量均高于中国煤、美国煤和世界;采用地壳丰度作为对比值所得到的富集系数严重偏离了煤中有害元素的分布特征,与中国煤、美国煤和世界煤相对比较,Cd高度富集,Cr、Cu、Ni、Pb、Sn、Ti为轻度富集至富集;不同煤层有害元素的富集程度存在较大的差异,Cd、Cr、Pb、Ni、Sn易出现富集,Cd为典型富集的有害元素,在8煤、7煤、6煤、5煤和4中出现高度富集;不同矿井主采煤层中有害元素富集程度存在差异,明显高度富集的有害元素为Cd、Ti;原煤灰分中的酸性组分超过灰成分的80%,灰成分指数平均碱酸比为9. 64%,煤中有害元素主要为陆源碎屑来源,部分存在自生矿物; As、Ni赋存富集于黄铁矿中,Ba、Mn可能赋存富集于碳酸盐矿物中,Cr可能吸附富集于粘土矿物中、Pb、Sn、Ti可能与硫酸盐矿物有关,Zn、Cu可能赋存在闪锌矿中,Cd可能赋存富集于黄铁矿和吸附富集于粘土矿物中,其富集程度与沉积环境和煤层稳定程度有关。

Characteristics of Distribution, Enrichment and Occurrence of Harmful Element in Carboniferous-Permian Coal from Huainan Coalfield

In order to investigate the characteristics of distribution, enrichment and occurrence of the harmful elements from Carboniferous-permian coal in Huainan coalfield, 159 coal samples were collected from Zhangji coal mine, Pansan coal mine and Guqiao coal mine, and trace elements were tested by ICP-MS, the concentration distribution characteristics, the enrichment characteristics of 11 types of the harmful elements was analyzed, the occurrence characteristics of the harmful elements was discussed by clustering map. The results show that the average content from most of the harmful elements is lower than the continental crust abundance except As, the average content from most of the harmful element is higher the average value of them in Chinese coal, American coal and the international coal except Ba and As. The enrichment coefficients calculated by the continental crust abundance seriously deviate from the concentration distribution characteristics of the harmful elements in coal from the studied area. Comparison with Chinese coal, American coal, and the international coal, Cd has highly enriched, Cr, Cu, Ni, Pb, Sn, Ti occur slight enrichment to enrichment. The enrichment level of the harmful element in the different coal seams is different, Cd, Cr, Pb, Ni, Sn are easily enriched. Cd as a typically harmful enrichment element has highly enriched in coal No.8, No.7, No.6, and No.5. There is difference in the enrichment level of the harmful elements in the main mining coal seam from the different coal mines, the obvious highly enriched harmful elements are Cd, Ti. The acidic content in the ash content of the raw coal is beyond 80%, the ratio between alkali and acid in the index of ask component is 9.64%, the harmful elements in coal mainly derive from terrigenous clastic deposits, and the partial harmful elements form the authigenic minerals. As and Ni occur and enrich in the pyrite, Ba and Mn may occur and enrich in the carbonate minerals, Cr may be adsorbed and enrich in the clay minerals, the occurrence and enrichment of Pb, Sn and Ti may be related with the sulfate minerals, Zn and Cu may occur in the sphalerite. Cd may occur and enrich in the pyrite or may be adsorbed and enrich in the clay minerals.