摘要
基于全尾砂絮凝过程中絮团弦长的测定,分别研究絮凝和沉降两个过程:首先以絮团平均弦长为指标研究不同絮凝条件下全尾砂絮凝行为,再以固液界面初始沉降速率为指标分析不同絮凝全尾砂料浆的沉降行为.探明了不同絮凝条件下全尾砂尺寸演化规律,全尾砂均快速絮凝形成絮团,絮团的平均弦长增长达到峰值后随着剪切时间逐渐下降,直至达到稳定状态.发现全尾砂絮团的平均弦长与絮凝全尾砂料浆固液界面的初始沉降速率随着不同的絮凝条件而不断改变,确定了在本文研究范围内的最优絮凝条件:Magnafloc 5250絮凝剂,全尾砂料浆固相质量分数10%,絮凝剂单耗10 g·t^-1,絮凝剂溶液中絮凝剂质量分数0.025%,剪切速率94.8 s^-1.最优条件下絮凝过程中絮团平均弦长峰值为620.63μm,絮凝结束时絮团平均弦长为399.57μm,絮凝全尾砂料浆固液界面初始沉降速率为4.61 mm·s^-1.初步建立了适用于本文全尾砂的基于絮团平均弦长的固液界面初始沉降速率模型,固液界面初始沉降速率随着絮团平均弦长的增加而增加,为实际生产中控制全尾砂絮凝沉降参数以及设备结构优化、提高全尾砂料浆的絮凝沉降效率提供参考.
Deep-cone thickening of unclassified tailings is one of the key technologies in the field of cemented paste backfill.Flocculation and settling behavior of unclassified tailings constitute key research topics of the deep-cone thickening technology.Based on the measurement of the floc chord length during the unclassified tailings flocculation process,this study investigated the flocculation and settling processes independently,which is different from the traditional research.First,the average chord length of the floc was used as the index to study the flocculation behavior of the unclassified tailings under different conditions.Then,the initial settling rate of the suspension–supernate interface was used as the index to analyze the settling behavior of the unclassified tailings slurry under varying flocculation conditions.Under different flocculation conditions,the unclassified tailings particles were flocculated rapidly and the average chord length of the floc increased rapidly to the peak value.Then,it decreased gradually with the shear time until it reached a stable state.It was found that the average chord length of the flocs of the unclassified tailings and the initial settling rate of the suspension–supernate interface of the flocculated,unclassified tailings slurry vary with flocculation conditions.For the scope of this study,the optimal flocculation conditions were determined as follows:the flocculant used was Magnafloc 5250,the solid mass fraction was 10%,the flocculant dosage was 10 g·t^-1,the flocculant mass fraction was 0.025%,and the shear rate was 94.8 s^-1.Under such flocculation conditions,the peak value of the average chord length of the floc was 620.63μm,the average chord length after the flocculation was 399.57μm,and the initial settling rate of the suspension–supernate interface of the flocculated tailings slurry was 4.61 mm·s^-1.The initial settling rate model of the suspension–supernate interface,applicable only to the tailings used in this study,was established preliminarily based
作者
阮竹恩
吴爱祥
王建栋
尹升华
王勇
RUAN Zhu-en;WU Ai-xiang;WANG Jian-dong;YIN Sheng-hua;WANG Yong(School of Civil and Resource Engineering,University of Science and Technology Beijing,Beijing 100083,China;Key Laboratory of the Ministry of Education of China for High-efficient Mining and Safety of Metal Mines,University of Science and Technology Beijing,Beijing 100083,China)
出处
《工程科学学报》
EI
CSCD
北大核心
2020年第8期980-987,共8页
Chinese Journal of Engineering
基金
国家自然科学基金重点资助项目(51834001)
国家自然科学基金面上资助项目(51674012)
国家自然科学基金青年科学基金资助项目(51804015)。
关键词
全尾砂
絮团弦长
聚焦式激光反射测量系统
剪切速率
固液界面初始沉降速率
unclassified tailings
floc chord length
focused beam reflectance measurement
shear rate
suspension–supernate interface initial settling rate
