同轴旋转磁场作用下重介质旋流器分选效果研究.pdf

硕士学术学位、硕士非工程类专业学位 学位论文答辩信息表 论文题目 同轴旋转磁场作用下重介质旋流器分选效果研究 课题来源* 国家自然科学基金项目 论文答辩日期 2020.06.11 答辩秘书 杨宏丽 学位论文答辩委员会成员 姓名 职称 博导/硕导 工作单位 答辩委员 会主席 王怀法 教授 博导 太原理工大学 答辩委员 1 董连平 副教授 硕导 太原理工大学 答辩委员 2 李志红 副教授 硕导 太原理工大学 *课题来源可填国家重点研发计划项目、国家自然科学基金项目、 国家社科基金项目、教育部人文社科项目、国家其他部委项目、省科技厅 项目、省教育厅项目、企事业单位委托项目、其他 摘 要 I 摘 要 为了探究旋转磁场与离心力场形成的复合力场对以磁铁矿粉作为重介 质的重介旋流器分选效果的影响，本文将永磁铁制作成的 N-S 交替磁场、 全 N 布置磁场以及 N/S 对角布置磁场同轴放置于重介旋流器顶盖及筒体位 置，开展同轴旋转磁场放置位置、磁极布置方式、磁场强度、磁场旋转速度 以及入料压力对重介质旋流器分选作用的影响研究。以旋流器内重介质分 配规律试验， 以及特定试验条件点的粗煤泥分选试验， 对分选效果进行了评 定。利用有限元分析软件 ANSYS MAXWELL 中的静磁场模拟分析功能对 磁场特性进行了分析。 将同轴旋转磁场安装于旋流器顶盖及筒体位置， 静磁场时， 入料流量大 幅度升高， 入料压力大幅度下降。 随着磁场旋转速度的增加， 流量随之下降， 压力有所上升。当加装静磁场时，底流密度大幅降低， 溢流密度随之增加。 随着磁场旋转速度的增加，溢流密度开始下降，底流密度开始上升。 且不同 的磁场强度以及磁极布置方式下底流与溢流密度的变化幅度存在差异。 将同轴旋转磁场安装于旋流器顶盖位置，粗煤泥分选试验结果表明， 1.5 mm 粒级灰分从 15.66降低至 11.34，尾煤灰分从 80.00略有增加 至 80.32。 1.5-1 mm 粒级灰分从 13.20降低至 10.77， 尾煤灰分从 76.83 略有降低至 76.50。1-0.5 mm 粒级灰分从 12.39降低至 10.05，尾煤灰 分从 76.96降低至 75.66。0.5-0.25mm 粒级精煤灰分从 11.20增加至 11.61， 尾煤灰分从 77.97降低至 74.94。 0.125-0.25 mm 精煤灰分从 11.87 增加至 14.04， 尾煤灰分从 85.78降低至 84.86。 旋转磁场有利于 0.5 mm 以上粒级粗煤泥的分选。 同轴旋转磁场位于旋流器筒体时降低了 0.25 mm 以上各粒级精煤灰分， 1.5 mm 粒级精煤灰分从 16.57降低为 14.29，尾煤灰分从 80.85略有 增加至 81.01。1.5-1 mm 粒级精煤灰分从 13.73降低为 12.57，尾煤灰 分从77.35降低至75.97。 1-0.5 mm粒级精煤灰分从12.60降低为11.30， 尾煤灰分从 77.69降低至 76.14。0.5-0.25 mm 粒级精煤灰分从 11.25降 低至 10.64，尾煤灰分从 80.51略有降低至 80.19。0.125-0.25 mm 粒级 精煤灰分有所增加从 11.51升高至 11.91，尾煤灰分基本保持不变。重产 物分配曲线表明， 与无磁场时相比静磁场的存在降低了分选密度及精度， 旋 转磁场时分选精度与分选密度略有降低。 还比较了不同磁场强度， 入料压力，磁极布置方式下的灰分变化。随着 太原理工大学硕士学位论文 II 磁场强度的增加， 精煤灰分基本呈现下降的趋势。 不同磁极布置方式下， N- S 布置方式对应的各粒级精煤灰分最低。 随着入料压力的增加， 各粒级精煤 灰分呈现下降的趋势。 采用 ANSYS MAXWELL 有限元分析软件，对磁极布置方式以及磁场 强度进行了模拟计算及分析。结果表明，全 N 布置方式下，几何中心位置 虽然距离磁极位置较远， 但是仍旧保留了较强的磁场强度， 磁感线分布较为 凌乱。N-S 布置方式下，几何中心位置处的磁场强度基本为零，但是磁感线 分布规律。磁极对角布置方式时，磁场强度的分布不均匀，几何中心位置处 存在较弱的场强。在粗煤泥分选试验过程中，N-S 布置方式下，分选效果更 为良好，说明磁场力作用范围较为集中的磁极布置方式能够实现旋流器内 磁性矿浆的加速，进而有利于旋流器的分选。 关键词关键词重介质旋流器，旋转磁场，复合力场，磁场模拟 ABSTRACT III ABSTRACT In order to investigate the effect of the composite force field ed by the rotating magnetic field and the centrifugal force field on the separation of the heavy medium cyclone using magnetite powder as the heavy medium, this paper will use the alternating magnetic field of NS, the magnetic field of all N and N / S Diagonally arranged magnetic field is placed coaxially on the top cover and barrel of the heavy medium cyclone, and the coaxial rotating magnetic field placement position, magnetic pole arrangement, magnetic field strength, magnetic field rotation speed and feed pressure are placed on the heavy medium cyclone Research on the impact of sorting. Experiments were carried out on the distribution law of heavy medium in the cyclone, and at the same time, the specific test conditions were selected to conduct the coarse slime separation test, and the separation effect was uated. The static magnetic field simulation analysis function in the finite element analysis software ANSYS MAXWELL was used to analyze the magnetic field characteristics. The coaxial rotating magnetic field is installed in the cyclone. When a static magnetic field is installed, the flow rate in the pipeline increases greatly and the pressure decreases greatly. As the rotation speed increases, the flow rate decreases and the pressure increases. When a static magnetic field is added, the underflow density is greatly reduced, and the overflow density is increased accordingly. As the rotation speed increases, the overflow density begins to decrease and the underflow density begins to increase. In addition, under different magnetic field strengths and magnetic pole arrangements, there are differences in the amplitudes of underflow and overflow density. The coaxial rotating magnetic field was installed at the position of the top cover of the cyclone. The results of the coarse slime separation test showed that the ash content of 1.5 mm particle size was reduced from 15.66 to 11.34, and the tail coal ash content was slightly increased from 80 to 80.32. The ash content of 1.5-1 mm particle size was reduced from 13.20 to 10.77, and the ash content of tailings was slightly reduced from 76.83 to 76.50. The ash content of 1-0.5 mm particle size was reduced from 12.39 to 10.05, and the ash content of tailings was reduced from 76.96 to 75.66. The ash content of 0.5- 0.25 mm granular clean coal increased from 11.20 to 11.61, and the ash 太原理工大学硕士学位论文 IV content of tail coal decreased from 77.97 to 74.94. The ash content of 0.125- 0.25 mm clean coal increased from 11.87 to 14.04, and the ash content of tail coal decreased from 85.78 to 84.86. The rotating magnetic field is beneficial to the sorting of coarse slime with particle size above 0.5 mm. When the coaxial rotating magnetic field is located in the cyclone barrel, the ash content of each grade of coal is reduced by more than 0.25 mm, the ash content of 1.5 mm particle size is reduced from 16.57 to 14.29, and the ash content of tail coal is slightly increased from 80.85 to 81.01. The ash content of 1.5- 1 mm granular coal was reduced from 13.73 to 12.57, and the tail coal ash content was reduced from 77.35 to 75.97. The ash content of 1-0.5 mm granular clean coal was reduced from 12.60 to 11.30, and the tail coal ash content was reduced from 77.69 to 76.14. The ash content of 0.5-0.25 mm granular coal was reduced from 11.25 to 10.64, and the tail coal ash content was slightly reduced from 80.51 to 80.19. The ash content of 0.125-0.25 mm granular coal has increased from 11.51 to 11.91, and the tail coal ash content has remained basically unchanged. The heavy product distribution curve shows that the presence of a static magnetic field reduces the sorting density and accuracy compared to when there is no magnetic field, and the sorting accuracy and sorting density decrease slightly when the magnetic field is rotating. In addition, the changes in ash content under different magnetic field strengths, feed pressures, and magnetic pole arrangements are compared. As the strength of the magnetic field increases, the ash content of clean coal basically shows a downward trend. Under different magnetic pole layouts, the ash content of each grade of clean coal corresponding to the N-S layout is the lowest. As the feed pressure increases, the ash content of each grade of clean coal shows a downward trend. Using ANSYS MAXWELL finite element analysis software, simulation calculation and analysis of different magnetic pole layouts and different magnetic field strengths were carried out. The results show that in the all-N arrangement, although the geometric center position is far from the magnetic pole position, it still retains a strong magnetic field strength, and the distribution of magnetic induction lines is messy. In the N-S arrangement, the magnetic field strength at the geometric center is basically zero, but the distribution of magnetic induction lines is regular. When the magnetic poles are arranged diagonally, the distribution ABSTRACT V of the magnetic field strength is uneven, and there is a weak field strength at the geometric center. In the course of coarse slime separation test, the separation effect is better under the N-S layout, indicating that the composite force field under the N-S layout is more suitable for the separation of coarse slime. In the course of coarse slime separation test, under the N-S arrangement, the separation effect is better, indicating that the magnetic pole arrangement with a concentrated magnetic force range can accelerate the magnetic slurry in the cyclone, which is beneficial to the cyclone Sorting. Keywords Heavy medium cyclone；Rotating magnetic field；Compound force field；Magnetic field simulation 太原理工大学硕士学位论文 VI 目 录 VII 目 录 学位论文原创性声明 ................................................................................................................. I 学位论文版权使用授权书 ......................................................................................................... I 摘 要 ......................................................................................................................................... I ABSTRACT ............................................................................................................................. III 目 录 .................................................................................................................................... VII 第一章 绪论 ............................................................................................................................ 1 1.1 研究背景及意义 ....................................................................................................... 1 1.1.1 研究背景 ........................................................................................................ 1 1.1.2 研究目的与意义 ............................................................................................ 2 1.2 国内外研究现状 ....................................................................................................... 2 1.2.1 传统重介质旋流器发展现状 ........................................................................ 2 1.2.2 重介质旋流器的调控方法 ............................................................................ 5 1.2.3 磁力旋流器发展现状 .................................................................................... 7 1.2.4 磁场对重介质旋流器的影响 ...................................................................... 11 1.2.5 磁力驱动技术与设备 .................................................................................. 13 1.3 研究内容 ................................................................................................................. 15 第二章 同轴旋转磁场试验系统的构建及试验方法 .......................................................... 17 2.1 试验用旋流器的设计及制作 ................................................................................. 17 2.1.1 旋流器的设计及制作 .................................................................................. 17 2.1.2 旋转机构及传动机构的设计与制作 .......................................................... 19 2.2 试验系统构建 ......................................................................................................... 19 2.2.1 试验系统及主要设备选型 .......................................................................... 19 2.2.2 试验平台的构建 .......................................................................................... 20 2.3 样品性质 ................................................................................................................. 22 2.3.1 煤样粒度组成 .............................................................................................. 22 2.3.2 煤样密度组成 .............................................................................................. 23 2.3.3 重介质性质 .................................................................................................. 24 2.4 永磁场构建 ............................................................................................................. 25 2.5 试验方法及评价指标 ............................................................................................. 26 2.5.1 重介质分配试验 .......................................................................................... 27 2.5.2 粗煤泥分选试验 .......................................................................................... 27 太原理工大学硕士学位论文 VIII 2.5.3 重选效果评定 .............................................................................................. 27 2.5.4 Ansoft Maxwell 有限元磁场分析方法 ....................................................... 28 第三章 同轴旋转磁场作用于旋流器顶盖的分选试验研究 .............................................. 29 3.1 磁极布置方式试验研究 ......................................................................................... 29 3.1.1 介质分配试验 .............................................................................................. 29 3.1.2 粗煤泥分选试验 .......................................................................................... 30 3.2 磁铁数量分选试验研究 ......................................................................................... 33 3.2.1 介质分配试验 .............................................................................................. 33 3.2.2 粗煤泥分选试验 .......................................................................................... 35 3.3 旋转速度分选试验研究 ......................................................................................... 37 3.3.1 介质分配试验 .............................................................................................. 37 3.3.2 粗煤泥分选试验 .......................................................................................... 38 3.4 入料压力分选试验研究 ......................................................................................... 41 3.4.1 无磁粗煤泥分选试验 .................................................................................. 41 3.4.2 有磁场粗煤泥分选试验 .............................................................................. 42 3.5 同轴旋转磁场对于分选过程流量及压力的影响 ................................................. 44 3.5.1 对流量的影响 .............................................................................................. 44 3.5.2 对压力的影响 .............................................................................................. 45 3.6 同轴旋转磁场对分选性能的影响 ......................................................................... 47 3.7 本章小结 ................................................................................................................. 50 第四章 同轴旋转磁场作用于旋流器筒体的分选试验研究 .............................................. 51 4.1 磁极布置方式分选试验研究 ................................................................................. 51 4.1.1 介质分配试验 .............................................................................................. 51 4.1.2 粗煤泥分选试验 .......................................................................................... 53 4.2 磁铁数量分选试验研究 ......................................................................................... 55 4.2.1 介质分配试验 .............................................................................................. 55 4.2.2 粗煤泥分选试验 .......................................................................................... 57 4.3 旋转速度分选试验研究 ......................................................................................... 59 4.3.1 介质分配试验 .............................................................................................. 59 4.3.2 粗煤泥分选试验 .......................................................................................... 60 4.4 入料压力分选试验研究 ......................................................................................... 63 4.4.1 重介质分配试验 .......................................................................................... 63 4.4.2 粗煤泥分选试验 .......................................................................................... 64 4.5 同轴旋转磁场对于分选过程流量及压力的影响 ................................................. 67 目 录 IX 4.5.1 对流量的影响 .........