中国选煤工艺的洁净煤地质研究

China is one of seldom developing countries taken coal as main energy in energy structure, and its air pollution belongs to typical coal-burning air pollution. It is the times requirements of Chinese energy to rapid develop clean coal technology for making reasonable utilizaiton in coal resoures. In this project, some hazardous substances in coal, ash (mineral matter), sulfur, and trace elements, were selected, the distribution characteristics of these coals with hazardous substances and occurrence conversion, and distribution regularities of these hazardous substances during coal procession and utilization were systematically discussed during coal preparation process before combustion by using some modern analytical methods: confocal microscopy, electron microscopy, micro-probe techniques, X-light technique, and ICP-MS, etc. Various coal preparation technologies were used, such as heavy-medium, and flotation, etc. Meanwhile, the modes of enrichment, dissemination and migration of these hazardous subatances in burial coal bed and coal procession and utilization were studied and the cleaning potentials of different type coals and different regional coals were deeply evaluated by establing synthesized cleaning potential parameters. The spatial and temporal distributions characteristics of coal cleaning potential were investigated by using big data/cloud computing combined with some methods, mathematical statistics, mathematical geology, and geographic information technology. These work results can provide scientific foundation for choosing clean coal technology and making reasonable usage of different quality coals and different grade coals in Chinese coal resources.

中国是少数几个能源结构以煤炭为主的发展中国家，空气污染属典型的煤烟型大气污染，合理利用煤炭资源，大力发展洁净煤技术是我国能源的时代要求。本申请项目以煤中灰分（矿物质）、硫分、有害微量元素等有害物质为研究对象，以煤炭燃前加工利用的重介、浮选、浮选柱等选煤工艺为载体，采用共聚焦显微镜、电子显微镜、各类微区探针技术、X光技术、等离子质谱等现代测试技术，系统探讨煤中有害物质的煤炭资源赋存分布以及在加工利用过程中的赋存迁移分布规律，深入探讨有害物质的埋葬煤层和加工利用中的富集、嵌布及迁移模式，构建综合洁净潜力指标，评价不同类型不同区域煤的洁净潜力，利用数理统计、数学地质及地理信息等方法与技术，以大数据云计算揭示洁净潜力时空分布。研究成果为洁净煤工艺及煤炭分质分级的合理利用提供科学依据。

项目以中国北方山西省六大煤田和陕西多个矿区的侏罗与石炭二叠纪高硫难选煤为研究对象，以重介、跳汰、浮选、干扰床煤泥分选（TBS）等选煤工艺为载体，利用多学科理论，采用SEM-EDS、ICP-MS等现代先进测试手段及Map GIS等多种分析方法对煤中矿物、有害元素等物质开展了赋存分布及大数据研究。研究表明，煤的洁净可选性与煤中矿物赋存状态和嵌布类型有关，与矿物质含量无关，矿物为腔填型、细分散型赋存形式极难脱除，嵌布粒度在2-6μm的矿物颗粒极难分离；煤中矿物与有害元素的赋存、嵌布、解离度及脱除率与成煤环境有关，陆相上三角洲环境形成的煤可选性比近海型潮坪环境形成的煤易选，海陆交互相环境下形成的煤矿物质脱除性最为复杂；煤中矿物的赋存状态和嵌布类型控制了煤可选性，亲硫元素易脱除，有机硫及非矿物无机质及亲石元素较难选。针对选煤工艺，提出了煤的洁净度、洁净潜势度等新指标，运用数据库和MapGIS技术，分析了山西省石炭二叠系煤的质量等级、洁净煤等级分布特性，构建了山西晚古生代煤的煤灰分、硫分、有害微量元素大数据库，评价了矿区及煤田煤的洁净时空潜势特性。项目丰富了煤的洁净时空分布及可选性理论，为煤的分质分级利用提供了科学依据。