【作者】 张晓逵；

【导师】 宋党育；

【作者基本信息】 河南理工大学 ， 地质资源与地质工程， 2010， 硕士

【摘要】 煤中重金属元素的含量及其在煤中的赋存状态是影响其在煤炭加工和利用过程中环境效应的决定因素,对煤中的微量元素进行定量和赋存状态的研究,能够为煤中有害微量元素迁移、富集规律提供理论依据,以期寻求有效的可控脱除技术,减少煤中重金属元素的环境危害。因此研究煤中重金属元素的含量和赋存特性具有重要的理论意义和现实意义。采用密闭的微波消解装置,利用不同的酸、功率、溶样时间进行多次微波条件实验,寻求最佳溶样效果,确立微波消解处理煤样的优化方法,应用ICP-MS、原子荧光光谱仪、XRD、逐级化学提取分析等多手段测定,分析山西、河南部分煤中的As、Se、Pb、Cr、Cd、Hg等微量重金属元素的含量水平及赋存状态,并应用XRD对煤中的无机矿物组分进行物相分析,深入剖析重金属元素和矿物组分间的亲和关系,揭示了重金属元素在煤中的分布特性,为建立煤中重金属元素聚集的地质地球化学模式提供理论依据。(1)从煤样消解方法看,利用密闭微波消解法,采用HNO3-H2O2混合体系达到最佳溶样效果,优化了实验条件,为煤样微波消解提供依据。(2)从定量分析的结果看,山西煤样品中铬、硒、汞的平均含量均低于河南煤样品的平均含量,而砷、镉的平均含量略高于河南样品中平均含量。与全国均值相比,山西煤样中铬、砷、镉的平均含量略高于全国均值,铅的平均含量远高于全国均值,硒、汞的平均含量略低于全国均值。河南煤样中铬、砷、硒、镉、铅和汞的平均含量都略高于全国均值。(3)从定性分析的结果看,样品中主要存在的矿物为高岭石、方解石和石英,还有部分伊利石、白云石,个别样品中还有白云母、黄铁矿和锐钛矿。(4)从赋存状态分析的结果看,煤样中铬、砷、硒、镉、铅和汞均具多种赋存状态,多数元素赋存状态以粘土矿物结合态、有机结合态和硫化物结合态为主,其次为水溶态和可交换态、铁锰氧化物结合态和碳酸盐结合态。更多还原

【Abstract】 The content of trace metals in coal and their modes of occurrence are the determinant elements which influence their use in coal processing and the process of environmental effects. Studies on quantitative analysis and occurrence characteristics in coal can provide a theoretical basis on hazardous trace elements migration and enrichment rule with a view to finding effective controllable removal technology, which reduces environmental hazards of trace metals in coal. Therefore, there is vitally important theoretical and practical significance to study harmful content of trace metals in coal and the occurrence characteristics.In this paper, Using the airtight microwave digestion systems, uses the different acid, the power, the dissolved time to carry on the multiple microwave condition experiment, seeks dissolves the type effect best, the establishment microwave resolution processing coal sample optimized method. ICP-MS, atomic fluorescence spectrometer, XRD, sequential chemical extraction analysis and many other means of measurement are used to analyze As, Se, Pb, Cr, Cd, Hg and other trace element content and occurrence of trace metals status in coal in Shanxi and Henan, and application XRD to phase analysis inorganic mineral compositions in coal, in-depth analysis relationships between trace metals and mineral components, which reveals distribution properties of the trace metals in coal to provides theoretical basis on establishment geological and geochemical model of harmful trace metals gathering in coal.(1)From the coal sample resolution method, using the airtight microwave resolution method, uses the HNO3-H2O2 mix system to achieve dissolves the type effect best, optimized the experimental condition, provides the basis for the coal sample microwave resolution.(2)From the results of quantitative analysis, the average content of chromium, selenium and mercury in the samples in Shanxi are lower than that of Henan; while the average content of arsenic, cadmium are slightly higher than that of Henan. Compared with the national average, the average content of chromium, arsenic, cadmium are slightly higher; while the lead is far higher and selenium and mercury are slightly lower. The average content of chromium, arsenic, selenium, cadmium, lead and mercury in the samples in Henan are slightly higher than that of the national average.(3)From the results of qualitative analysis, in the samples there is mainly kaolinite, calcite and quartz, as well as some of illite, dolomite, and muscovite, pyrite, and anatase exit in individual samples.(4)From the results of occurrence analysis, the chromium, the arsenic, the selenium, the cadmium, the lead and the mercury have many kinds of modes of occurrence in the coal sample. Modes of occurrence of the most element focus on the clay mineral union condition, the organic synthesis condition and the sulfide union condition primarily, next for water-soluble condition and the exchange condition, the iron and manganese oxide condition and the carbonate condition.更多还原