河北开滦矿区煤洗选过程中 15种主要有害微量元素的迁移和分配特征

以河北开滦矿区晚古生代煤及其洗选产品为例,运用电感耦合等离子体质谱 (ICP-MS)和冷原子吸收光谱 (CV-AAS)方法对煤中主要微量有害元素 (包括 Be、 Cr、 Co、 Ni、 Cu、 Zn、 Ga、 As、 Se、 Mo、 Tl、 Pb、 Th、 U和 Hg)的含量及其在洗选过程中的迁移和分配特征进行了研究.通过对开滦矿区 10个矿井 47个煤层刻槽样品主要有害微量元素含量的统计,发现开滦矿区晚古生代煤中 Cr、 Ni、 Cu、 Zn、 Pb和 As富集.通过对原煤精煤中煤尾煤煤泥两套系列样品的分析,发现主要有害微量元素在精煤中都有不同程度的脱除,中煤中相对富集的元素有 Se和 Th,明显被脱除的元素有 Co和 Tl.除 Tl以外,尾煤中主要微量有害元素均有不同程度的富集,以 As的富集率最高,可达 34.4%, Hg的富集率最低,为 1.1%.煤泥中所有微量有害元素均相对富集,以 Hg的相对富集率最高,达 78.4%.因此,如果对尾煤和煤泥加以利用,需要特别关注 As和 Hg等微量有害元素对环境的影响.主要微量有害元素在洗选过程中的分配行为主要受控于它在煤中的赋存状态.

Migration and distribution of fifteen toxic trace elements during the coal washing of the Kailuan Coalfield, Hebei Province

The contents and migration and distribution of toxic trace elements (including Be, Cr, Co, Ni, Cu, Zn, Ga, As, Se, Mo, Tl, Pb, Th, U, and Hg) during the coal washing of the Paleozoic coals and their washing products were determined using inductively coupled plasma mass spectrometry (ICP-MS) and cold-vapor atomic absorption spectrometry (CV-AAS). The results show that elements, such as Cr, Ni, Cu, Zn, Pb, and As are a little enriched in the coals from the Kailuan Coalfield. According to the study of two sets of raw coal, cleaned coal, middling coal, tailings, and slime, it is found that the toxic trace elements are all removed to some extent in the cleaned coal. Se and Th are relatively enriched in the middling coal, and Co and Tl are relatively removed. Except for Tl, the toxic elements are enriched in the tailings among which As is the highest enriched, as high as 34.4%, but Hg the lowest enriched, as low as 1.1%. The toxic trace elements in the coal slime are all enriched, and Hg is the highest enriched. Therefore, special attentions should be focused on As and Hg if the tailing and coal slime are used. The migration and distribution of toxic trace elements during coal washing are controlled by their occurrence.