浮选颗粒条栅结构表面润湿行为特性研究  

Study of grid-structured flotation particle surface wetting behavior characteristics

作　　者：张锐[1,2] 于锋 邢耀文[4,5] 桂夏辉[4,5] ZHANG Rui;YU Feng;XING Yaowen;GUI Xiahui(State Key Laboratory of Coal Mine Disaster Dynamics and Control,Chongqing University,Chongqing 400044,China;School of Resources and Safety Engineering,Chongqing University,Chongqing 400044,China;Wuhai Energy Co.Ltd.,China National Energy Group,Wuhai 016000,China;State Key Laboratory of Coking Coal Resources Green Exploitation,China University of Mining and Technology,Xuzhou 221116,China;National Engineering Research Center of Coal Prepara-tion and Purification,China University of Mining and Technology,Xuzhou 221116 China)

机构地区：[1]重庆大学煤矿灾害动力学与控制全国重点实验室,重庆400044 [2]重庆大学资源与安全学院,重庆400044 [3]国家能源集团乌海能源有限责任公司,内蒙古乌海016000 [4]中国矿业大学炼焦煤资源绿色开发全国重点实验室,江苏徐州221116 [5]中国矿业大学国家煤加工与洁净化工程技术研究中心,江苏徐州221116

出　　处：《选煤技术》2024年第4期13-21,共9页Coal Preparation Technology

基　　金：国家资助博士后研究人员计划项目(GZC20233329)。

摘　　要：矿物颗粒间表面润湿性差异是浮选成功的关键,受表面化学性质与物理形貌结构的双重影响。为进一步明确表面物理形貌结构对液滴在矿物颗粒表面上润湿行为的影响,采用光刻显影技术制备了5种具有不同粗糙度系数和表面面积分数的条栅结构聚二甲基硅氧烷(PDMS)表面,并利用自制的动/静态接触角测量系统及润湿三相接触线行为测试系统对液滴在PDMS表面上的润湿行为进行了测试。动/静态接触角测试结果表明:当表面粗糙度系数相同时,固体表面面积分数增加,条栅结构表面不同润湿方向上的接触角均呈减小趋势,而当表面面积分数相同时,条栅结构表面不同润湿方向上的接触角则与固体表面粗糙度系数呈正相关;此外,各样品表面垂直于条栅结构方向的动/静态接触角均大于平行方向(即θ_(⊥)>θ_(∥)),且不同润湿方向上接触角的差异随样品表面润湿性的增强而减小。动态接触角测试结果还表明:表面接触角滞后(Δθ=θ_(a)-θ_(r))与表面面积分数呈正相关,而与表面粗糙度系数呈负相关,且前进与后退接触角的预测值与试验值基本吻合,说明动态接触角能够真实地反映固体表面润湿性;此外,在液滴滚动时,其运动行为总是周期性地发生后端接触线先从固体表面分离,而后液滴重新与固体表面发生黏附形成新的前端接触线的过程,这种运动特性在不同条栅结构表面上完全相同。润湿三相接触线行为测试结果表明:液滴在条栅结构表面优先沿着条栅结构方向润湿或去润湿,而跨越条栅结构润湿时,受表面微结构的“钉扎”作用,润湿半径远小于平行润湿方向,且三相接触线在不同条栅结构表面的移动均呈现“解钉—钉扎—再解钉—再钉扎”的一种断续周期性过程。研究结果深化了矿物颗粒表面物理形貌结构对其润湿行为特性的影响,可为后续通过表面形貌调控颗粒表�Difference of mineral particles in surface wettability is the key to success of flotation process,and the wetting characteristics are influenced by both surface chemical properties and physical morphological structure.In order to further clarify the influence of surface physical morphology on wetting behavior,five groove-structured surfaces with different roughness coefficients and percentages of surface area are prepared with polydimethysiloxane sheet(PDMS)as material and through photo-engraving process.Then the wetting behavior of droplets on PDMS surface is explored using self-made dynamic/static contact angle measuring system and the three-phase contact line movement testing system.As indicated by both dynamic and static contact angle measurements,when the surface roughness remains unchanged,the contact angles in different wetting directions on groove-structure surface all tend to decrease with the increase of surface area,and when the percentages of surface area are identical,the contact angles in different wetting directions are positively correlated with roughness of solid surface;the dynamic and static contact angles of droplets in the direction perpendicular to the grooves on the surfaces of different specimens are all greater than those in the parallel direction(i.e.θ_(⊥)>θ_(∥)),and the difference in values of contact angles in different wetting directions tends to decrease with the increased wettability of solid surface.Results of test on dynamic contact angles also indicate that the hysteresis of contact angels(Δθ=θ_(a)-θ_(r))is positively correlated with percentage of surface area and negatively correlated with surface roughness,and the predicted values of both forward and receding contact angles are basically in agreement with the actually measured values,indicating that the dynamic contact angels of droplets can truly reflect the change in surface wettability;and the droplet when rolling is observed to always undergo a cyclic motion on different structured solid surfaces,namely,its rear-e

关 键 词：浮选 润湿行为 条栅结构 表面形貌 动/静态接触角测量 三相接触线行为测试 各向异性 断续周期性 

分 类 号：TD943[矿业工程—选矿]