煤泥浮选中黏土的表/界面动态特征及PEO抑制泥化机理

黏土，特别是膨胀型黏土在水中存在“表面水化—渗透膨胀—晶层分散”这一动态过程，所以是造成高灰煤泥浮选效率低的关键因素之一。前期工作表明，低分子量PEO（聚乙二醇）可以抑制黏土分散泥化，强化煤泥浮选效果。本项目以煤系黏土为对象，采用表/界面测试、分子动力学模拟计算等手段，首先研究黏土晶层膨胀分散与颗粒表/界面性质变化的动态关系，及其对煤泥浮选的影响机制；其次，基于试验和模拟计算研究PEO在煤/黏土/水这一复杂体系中的选择性吸附行为；最后通过PEO在黏土层间域的吸附作用能计算和构象解析，揭示其抑制黏土晶层膨胀分散的机理。项目旨在明晰低分子量PEO对高灰难选煤泥浮选的强化机制，以期为煤泥浮选过程黏土行为调控提供一定的理论基础和技术参考。

Clay minerals, bentonite sepecially, easily swell and disperse into platelets. It has been acknowleged that clays have a significant effect on the rheological and chemical characteristics of pulp, ultimately decrease flotation recovery. polyethylene glycol （PEO）can inhibit clay swelling and dispersing and has been used as expansive retarder in oil production. This project introduces the idea of clay dispersion controlling into fine coal flotation. The investigation will include the influence of clay swelling and dispersion on its interface properties with AFM, Cryo-SEM, XRD and other testing methods. Using quantum chemistry calculation method, the selective mechanism of PEO coating on clay and coal surface will be researched and strengthened process will be developed. As a result of this research project, the flotation mode will upgrade from end-of-pipe to a start-of-pipe mode. With a view to enhancing coking coal flotation recovery and providing a theoretical basis to the flotation of coal with high ash content, but also for the strengthening of coal flotation easy mudding provide a new idea.