在煤炭资源的加工利用过程中,部分重金属元素会在环境中富集,对环境和人体均有一定 危害。 煤炭分选作为煤炭加工利用的前端处理工艺,可以去除煤中大部分矸石,但是目前对分选过 程中重金属元素的迁移研究较少。 选用内蒙古低灰高硫煤样和高灰低硫煤样进行浮沉、浮选试验, 通过电感耦合等离子质谱仪(ICP-MS)、X 射线衍射(XRD)、X 射线荧光分析(XRF)等测试方法研 究重金属铅元素在煤中的赋存形式及分选过程中的迁移富集规律。 试验结果表明:不同灰分煤样 中重金属元素赋存形式差别较大,对分选中的富集与迁移规律影响显著。 由逐级化学提取可知铅 元素有机结合态含量较少,约为 5%,整体表现出向矿物质中富集的趋势;浮沉试验中铅元素在 2 种 煤中易于向较大密度 1.6 ~ 1.8 g / cm3 富集;浮选试验中铅元素趋于向尾煤中富集,且铅元素含量变 化与灰分能够保持一致性。 此外,低灰高硫煤尾煤中的铅与硫的含量变化呈现较好的一致性,而在 含有机硫较高的低硫煤中无此现象,表明铅受无机硫的影响较大。 以上规律表明,通过分选可将煤 中的大部分铅元素除去,进而提高煤的品质,降低煤中铅元素对环境及人体的危害。

During the utilization of coal resources,some heavy metal elements will be enriched in the environment, which is harmful to environment and human body. As a front-end treatment process for coal utilization,coal wash- ing can remove most of the gangue in coal,but there are currently few studies on the migration of heavy metals in the washing process. Inner Mongolia low-ash,high-sulfur coal samples and high-ash,low-sulfur coal samples were selected for floatation and flotation tests, and heavy metal lead ( Pb ) was studied by inductively coupled plasma mass spectrometry(ICP-MS),X-ray diffraction,X-ray fluorescence analysis and other test methods. The occurrence mode of Pb in the coal and the migration and enrichment behavior during coal washing process was investigated. The experimental re- sults showed that the occurrence mode of Pb in coal samples with different ash content was quite different,which had a sig- nificant impact on the migration and enrichment behavior during the washing process. By chemical sequential extraction,the content of Pb in the organic bound state was little,about 5%,and the overall trend was to be enriched in min- erals. In the float-and-sink test, Pb was easily enriched in higher density of 1. 6 - 1. 8 g / cm3 in the two coals. In the flotation test,Pb tended to be enriched in the tailings,and the change of Pb and ash content could maintain consistency.In addition,the changes in the content of lead and sulfur in the tailings of low-ash and high-sulfur coal showed a good consistency,but there was no such phenomenon in the low-sulfur coal with higher organic sulfur,indicating that lead was greatly affected by inorganic sulfur. It indicated that most of the Pb in coal could be removed by washing process, thereby improving the coal quality and reducing the harm of heavy metals in coal to the environment and human body.