摘要
为揭示水力剪切条件对两步絮凝过程絮体尺寸演化的影响规律,基于聚焦束反射测量(FBRM)技术,实时监测高岭石颗粒在两步絮凝过程中絮体尺寸的动态变化,系统评估了初次剪切速率与时间(G_(1)、T_(1))以及二次剪切速率与时间(G_(2)、T_(2))对絮体形成、破碎与重组过程的调控效应。结果显示,初次剪切阶段是决定絮体成核与初级结构形成的关键,适度的剪切速率(G_(1)=400 r/min)与持续时间(T_(1)=90 s)有助于形成粒径大、结构稳定的絮体,而剪切过强或过长则易导致絮体提前破裂,呈现明显的“生长-破碎”临界行为。二次剪切阶段则主导高阶结构的重组与稳定,适中的剪切条件(G_(2)=200 r/min,T_(2)=180 s)可有效促进再絮凝过程并提升絮体完整性,而过大的剪切强度或剪切持续时间将导致已形成絮体的边缘剥离或骨架解构,粒径回缩,体现出“再聚-解构”的非线性演化特征。研究明确了剪切速率与时间在不同阶段的作用边界与协同匹配机制,为复杂工况下高效絮凝控制与结构调控提供了理论依据与技术支持。
To investigate the influence of hydraulic shear conditions on the floc size evolution during the two-step flocculation process,this study employed focused beam reflectance measurement(FBRM)to monitor,in real time,the dynamic changes in floc size of kaolinite particles.A systematic evaluation was conducted on the regulatory effects of primary shear rate and duration(G_(1),T_(1)),as well as secondary shear rate and duration(G_(2),T_(2)),on floc formation,breakage and restructuring.The results showed that the primary shear stage was critical for floc nucleation and the formation of primary structures.Moderate shear intensity(G_(1)=400 r/min)and duration(T_(1)=90 s)promoted the generation of large,structurally stable flocs,whereas excessive shear strength or prolonged duration led to premature breakage,exhibiting a distinct“growth-breakage”threshold behavior.The secondary shear stage predominantly governed the reorganization and stabilization of higher-order floc structures.Appropriate shear conditions(G_(2)=200 r/min,T_(2)=180 s)effectively enhanced reflocculation and improved floc integrity,while excessive shear intensity or prolonged exposure caused edge peeling or framework disintegration,resulting in size reduction and a nonlinear“reflocculation-deconstruction”evolution pattern.This study delineates the functional boundaries and synergistic interplay of shear rate and duration at different stages,providing a theoretical foundation and technical support for efficient flocculation control and structural regulation under complex conditions such as tailings water treatment.
作者
王露
李硕夫
马力强
朱阳戈
WANG Lu;LI Shuofu;MA Liqiang;ZHU Yangge(BGRIMM Technology Group,Beijing 100160,China;State Key Laboratory of Mineral Processing,Beijing 102628,China;China University of Mining and Technology,Beijing 100083,China;China Nonferrous Metal Mining(Group)Co.,Ltd.,Beijing 100029,China)
出处
《有色金属(选矿部分)》
2025年第9期120-129,共10页
Nonferrous Metals(Mineral Processing Section)
基金
矿冶科技集团有限公司青年科技创新基金(04-2506)。
关键词
两步絮凝
剪切调控
FBRM
絮体尺寸演化
two-step flocculation
shear regulation
focused beam reflectance measurement(FBRM)
floc size evolution
