准东高钠煤中钠的富集机理及其动力学模型研究

Abundant coal resources have been found in Zhundong coal field, Xinjiang autonomous region. But the large scale utilization of Zhundong coal has been restricted by the high sodium contents in coal. Different geological environments and distribution characteristics have been found between Zhundong coal and high-sodium coals abroad. In this research, detailed investigations were conducted to analyze the distribution of sodium in coal seams and rock stratum, and the paragenetic association of sodium and other elements, macerals, minerals. The modes of occurrences and material sources of sodium in Zhundong coal were analyzed by a variety of research methods. The syngenetic sodium in coal were classified considering the enrichments of inorganic elements in depositional stages, the weathering effect in geological history, while the epigenetic sodium were also classified considering the leaching characteristics of groundwater and constraints of porosity. Two different enrichment modes, weathered leaching of surface saline- groundwater transportion - sodium in coal and dissolved halogenide- groundwater transportion - sodium in coal were compared. The influences of enrichment modes on the paragenetic association of sodium and other anions were conducted. The groundwater dynamics mechanisms of sodium into coal seams and the dynamics mechanisms of physic-absorbed sodium in pores were illuminated based on the principles of groundwater dynamics and porosity characters of coal seams. Dynamics of groundwater and dynamic adsorption model of sodium enrichment in coal were established. The material sources, controlling factors and enrichment dynamics of sodium in Zhundong coal will be resolved by multidisciplinary studies conducted in this research.

准东煤田煤炭资源丰富，但煤中钠含量高的问题一直制约着准东煤的高效应用。目前的研究表明，准东高钠煤呈现出与国外高钠煤不尽相同的成因。本项目通过分析准东煤田主要可采煤层及其上覆和下伏岩层中钠的分布特征，以及钠与其他元素之间的共生组合关系，研究钠在煤中的赋存状态及其物质来源。研究准东煤田泥炭沉积作用、地质历史表生风化作用、地下水淋滤作用、煤层孔隙束缚作用等因素对煤中同生和后生成因钠的控制作用，并探究准东煤中地表盐碱风化淋滤-地下水运移-煤中钠富集、卤化盐岩溶解-地下水运移-煤中钠富集等两种富集模式，及其对煤孔隙水中钠离子与其它阴离子共生组合的影响。在此基础上，结合地下水动力学原理和煤中孔隙特征研究，阐明钠进入煤中的地下水动力学机理和煤层孔隙吸附水合离子钠的动力学机理，建立煤中钠富集的地下水动力学和吸附动力学模型。通过以上多学科交叉研究，解决准东煤中钠的来源、主控因素及富集动力学等关键科学问题。

项目针对我国准东地区典型的高钠煤矿区，围绕准东煤中钠的赋存状态及其物质来源、钠的富集模式及其主控因素、钠富集的地下水动力学和孔隙吸附动力学模型开展研究，取得了以下成果：新疆高钠煤中钠的赋存状态以水溶态为主，矿物态钠的含量很低；除水溶态钠之外，新疆高碱煤中含有较高含量的水溶态钙、镁、硫酸根、氯等离子，随埋深变化，各种水溶态离子含量纵向变化显著；准东不同矿区煤中水溶态离子的组合模式有明显差异；新疆高钠煤中水溶态离子主要来源于地表盐岩；地表盐岩中水溶态离子向煤层迁移过程中，受离子交换作用的影响，煤中水溶态离子组合模式差异显著；新疆煤中碱含量高，是现代地质作用的产物，其成因与地下水淋溶富集密切相关；利用Fick第二定律和准二级吸附动力学模型建立了吸附动力学模型和钠进入煤层的扩散动力学模型。.四年来，项目组共发表学术论文7篇，其中SCI收录2篇，EI收录1篇；申请发明专利2项，获授权发明专利2项；获省部级科技进步一等奖1项、三等奖2项、中国煤炭工业协会创新团队奖1项。项目执行期间，项目负责人白向飞入选煤炭工业技术委员会煤炭加工利用与节能环保专家委员会委员；培养硕士研究生1名；项目骨干丁华获全国煤炭青年科技奖，入选中国青年科技工作者协会环境与能源科学专业委员会委员并兼任副秘书长，入选煤炭工业技术委员会质量技术委员会委员；项目组成员参加国内外学术交流会议30余次，作报告10余次。