煤泥调浆湍流强化作用机理与新型涡流强化调浆过程  

Turbulence enhancement mechanism of coal slime pulp conditioning and new type vortex enhancing pulp conditioning process

作　　者：张海军[1,2] 王海楠 陈瑞丰 闫小康[1,2] 郑恺昕 李丹龙 蒋善勇[4] ZHANG Haijun;WANG Hainan;CHEN Ruifeng;YAN Xiaokang;ZHENG Kaixin;LI Danlong;JIANG Shanyong(National Engineering Research Center of Coal Preparation and Purification,China University of Mining and Technology,Xuzhou221116,China;School of Chemical Engineering and Technology,China University of Mining and Technology,Xuzhou221116,China;School of Electric Power Engineering,China University of Mining and Technology,Xuzhou221116,China;Baicheng County Zhongtai Coal Coking Co.,Ltd.,Aksu842300,China)

机构地区：[1]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 [2]中国矿业大学化工学院,江苏徐州221116 [3]中国矿业大学电气与动力工程学院,江苏徐州221116 [4]拜城县众泰煤焦化有限公司,新疆阿克苏842300

出　　处：《煤炭学报》2022年第2期934-944,共11页Journal of China Coal Society

基　　金：国家自然科学基金资助项目(51974310);国家重点研发计划资助项目(2019YFC1904301)。

摘　　要：调浆过程为煤泥浮选提供良好的界面条件,是实现其高效分选的必要条件,其本质是一个多相流动过程,流体作用贯穿其中。聚焦煤泥调浆过程中的“湍流效应”,搭建了实验室型搅拌装置,利用数值模拟分析其湍流特征参量,研究了不同流场条件下颗粒分散特性和颗粒表面疏水性变化规律,并通过浮选试验进行验证,以此构建了基于湍流能量密度适配的新型涡流强化煤泥调浆过程,并分析其流场特性。研究结果表明:搅拌装置内存在流向相反的循环区,有利于颗粒分散,叶轮区流体流速和湍动能耗散率高于其他区域,叶轮叶片后存在尾涡,其发展状况与湍动能耗散率分布一致,叶轮区最小涡尺度最低,增强颗粒与药剂的相互作用,随着叶轮转速增大,流体流速和湍动能耗散率增大,最小涡尺度减小;颗粒分散浓度方差随着叶轮转速的增大而减小,低转速时搅拌装置底部颗粒浓度较高,分散效果差,包覆角随着叶轮转速的增大而增大,相同条件下,叶轮区颗粒包覆角最大,在试验范围内,叶轮转速增大,浮选产率增大;基于上述调浆过程中的湍流效应分析,构建了集成管流、错向旋流、撞击流等不同流场环境的煤泥调浆过程,并设计了MRM-800×3 600 mm型煤泥混合调质器,数值模拟表明该装置内湍流能量密度分配合理,旋流区流体流速较大,呈切向运动,撞击流区域流体运动剧烈,湍流能量密度大,最小涡尺度小,工业生产实践表明该装置矿浆通过量为300~500 m^(3)/h,在原有工艺条件下,浮选精煤回收率提高超过4%。It has been acknowledged that a conditioning process can provide favorable interfacial conditions for fine coal flotation, thereby being a required premise of its efficient separation. Essentially, a fine coal conditioning is a process involving multiphase flow, throughout which the role of fluid exists. This paper focused on the turbulence effect in the coal pulp conditioning process, and designed a laboratory stirring device. Numerical simulation was used to acquire the turbulent characteristic parameters of the stirring device. Additionally, the properties of particle dispersion and surface hydrophobicity were analyzed under different conditions of flow field to characterize the influence of flow field characteristics on fine coal conditioning process, which was further verified by flotation tests. Based on the studied above, a new type vortex enhancing pulp conditioning process with adapted turbulence energy density was constructed for fine coal conditioning, and the flow field characteristics were analyzed. The results indicated that there was a circulation area with opposite flow in the stirred tank to promote particle dispersion, and the fluid velocity, together with the turbulent kinetic energy in the vicinity of impeller, was higher than that of other region. Trailing vortexes were formed behind the blade, which exhibited similar development trends to the distribution of the turbulent kinetic energy. The Kolmogorov scale was the lowest in the impeller region to enhance particle-collector interaction. With the raising impeller speed, the fluid velocity and turbulent kinetic energy increased, while the Kolmogorov scale and variance of particle dispersion concentration decreased. At low impeller speeds, the particle concentration of the cell bottom was high, corresponding to poor dispersion performance. The wrap angle increased with rising impeller speed, and under the same condition, the maximum wrap angle of particles collected near the impeller was measured. In this experiment, the lager impeller speed c

关 键 词：煤泥 调浆 湍流 浮选 表面改性 

分 类 号：TD94[矿业工程—选矿]