摘要
开展半工业全尾砂浓密实验,借助计算机断层扫描与三维重构技术分析高质量分数底流床层内部孔隙结构特征;利用最大球算法研究孔隙连通规律,揭示剪切强化导水机理。研究结果表明:当给料体积分数为10%,絮凝剂单耗为30 g/t时,有/无剪切作用下的肃北钒铁矿全尾砂连续浓密底流质量分数分别可达58.5%和55.8%;当添加转速为2 r/min的剪切作用时,床层平均孔隙率从47.62%降低到40.98%;孔隙平均直径由23.11μm降低至19.01μm,孔隙数量变化较小;床层内部孔隙数量随床层高度上升而增多,分形盒维数由1.60~1.70增加到1.90~1.95;定义临界孔喉比为1,将导水通道划分为主通道、次通道和全封闭通道,床层内部存在主导水通道周围伴随着若干次导水通道;剪切作用对于重塑尾砂絮团排列方式继而形成导水通道实现强化排水具有重要意义。
A semi-industrial unclassified-tailings thickening experiment was carried out.The internal pore structure of bed with high mass fraction of underflow was analyzed by using CT scanning and 3D reconstruction technique.The rule of pore connectivity was studied based on the maximal ball algorithm,and the water conduction mechanism of shear strengthening was revealed.The results show that when the feed volume fraction is 10%and the agent consumption of flocculant is 30 g/t,the underflow mass fraction of vanadium iron ore in northern Gansu reaches 58.5%and 55.8%with or without shear action.When adding 2 r/min shear action,the average porosity of bed decreases from 47.62%to 40.98%.The pore average diameter decreases from 23.11μm to 19.01μm,but there is little change in the number of pores.The number of inner pore of bed increases with the height of bed,and the fractal box dimension increases from 1.60.1.70 to 1.90.1.95.The critical pore-throat ratio is defined to be 1,and the channels are divided into main channel,subchannel and completely closed channel.There are main water conduction channels which are accompanied by several subchannels.Shear action plays an important role in remolding unclassified-tailings floc arrangement and forming water conduction channels to achieve enhanced drainage.
作者
焦华喆
王树飞
吴爱祥
王贻明
杨亦轩
JIAO Huazhe;WANG Shufei;WU Aixiang;WANG Yiming;YANG Yixuan(School of Civil and Engineering,Henan Polytechnic University,Jiaozuo 454000,China;School of Civil and Environment Engineering,University of Science and Technology Beijing,Beijing 100083,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2019年第5期1173-1180,共8页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(51704094,51574013,51834001)
国家安全生产重大事故防治关键技术项目(henan-0005-2016AQ)~~
