球磨机介质离散传热及热力破碎特性研究.pdf

硕士学位论文 球磨机介质离散传热及热力破碎特性研究 Study on Discrete Heat Transfer and Thermal Breakage Behaviour of Charge in Ball Mills 作 者吴桂义 导 师彭玉兴 教授 中国矿业大学 二〇一九年四月 万方数据 学位论文使用授权声明学位论文使用授权声明 本人完全了解中国矿业大学有关保留、使用学位论文的规定，同意本人所撰 写的学位论文的使用授权按照学校的管理规定处理 作为申请学位的条件之一， 学位论文著作权拥有者须授权所在学校拥有学位 论文的部分使用权，即①学校档案馆和图书馆有权保留学位论文的纸质版和电 子版，可以使用影印、缩印或扫描等复制手段保存和汇编学位论文；②为教学和 科研目的，学校档案馆和图书馆可以将公开的学位论文作为资料在档案馆、图书 馆等场所或在校园网上供校内师生阅读、浏览。另外，根据有关法规，同意中国 国家图书馆保存研究生学位论文。 （保密的学位论文在解密后适用本授权书） 。 作者签名 导师签名 年 月 日 年 月 日 万方数据 中图分类号 TD453 学校代码 10290 UDC 621 密 级 公开 中国矿业大学 硕士学位论文 球磨机介质离散传热及热力破碎特性研究 Study on Discrete Heat Transfer and Thermal Breakage Behaviour of Charge in Ball Mills 作 者 吴桂义 导 师 彭玉兴 申请学位 工学硕士 培养单位 机电学院 学科专业 机械设计及理论 研究方向 矿山机械 答辩委员会主席 刘送永 评 阅 人 二○一九年五月 万方数据 致谢致谢 岁月如梭，韶光易逝，转眼间，为期三年的硕士研究生学习生涯即将结束， 期间的学习、科研经历将使我受益终生，此刻，种种情景犹如镜头快放般的从脑 中一闪而过，其中有亢奋、有苦楚、有激动，但更多的，还是感激 在即将完成博士研究生的学业之际， 我深深地感谢导师彭玉兴教授对我的悉 心指导。恩师无论在科研还是在生活上都给予了极大的关怀和帮助。回首数年来 自己在科研领域的进展，每一级进步的阶梯都凝结了老师的汗水。彭玉兴教授严 谨的治学态度、一丝不苟的科研精神、掌控全局的学术思维以及高尚的人格给我 留下了深刻的印象，并将使我受益终身。在此，谨向我的导师致以崇高的敬意和 衷心的感谢。 感谢李同清博士和尹自信博士在我试验和写作过程中帮助和指导， 共勉互励、 风雨同舟的生活使我求学路上不再寂寞。 感谢实验室常向东博士、徐春明博士以及熊力群、施雨雨、赵跃叶等实验室 的伙伴们在本课题研究中和论文写作中给予的指导和帮助。 感谢父母一直以来不辞辛劳不遗余力为我提供无忧无虑的成长环境， 在我迷 茫时给予我肯定与鼓励，你们永远是鞭策我不断前进的力量。 最后，感谢各位专家学者在百忙之中审阅我的论文，并给予宝贵的指导。在 此谨向各位专家学者表示深深的感谢 作者吴桂义 2019 年 4 月于徐州 万方数据 I 摘摘 要要 球磨机是冶金、选矿、化工等行业关键的粉磨设备，我国每年经球磨机粉磨 的物料总量高达数十亿吨，其耗电量约占我国发电总量的 2-5。球磨机的根 本作用是将入料矿石颗粒破碎至所需粒度， 然而矿石颗粒有效破碎能量仅占球磨 机输入能量的 0.5-1，球磨效率极低，能耗巨大。本文在国家自然科学基金面 上项目的资助下，针对球磨过程中磨矿温升和磨矿效率低的问题，开展研磨介质 运动形态研究、研磨介质运动特性研究、研磨介质冲击离散传热特性研究、铁矿 石热力破碎特性研究。 旨在掌握磨矿过程的能量损耗机理和铁矿石颗粒热力破碎 特性，为提高球磨机磨矿效率、降低能耗提供基础理论和技术支撑。 首先，基于球磨机研磨介质运动学理论，分析了研磨介质的运动状态和运动 特性；通过试验与仿真相结合的方法，解析了研磨介质特征参数与球磨机功率随 转速率、研磨介质填充率和提升条面角的变化规律，并构建了可以预测研磨介质 运动特征参数的数学模型。 接着，基于颗粒破碎理论，分析了颗粒破碎的能量转化率，构建了离散元传 热模型，开展了研磨介质、铁矿石颗粒及衬板之间传热、温升规律的离散元仿真 研究，解析了不同因素下颗粒系统的传热、温升规律。 最后，基于非线性总体平衡模型，开展了铁矿石颗粒热力破碎试验，解析了 铁矿石比破碎速率和粒度分布随入料粒度、预处理温度的变化规律，探究了铁矿 石颗粒运动规律与破碎规律的关联特性， 对比了铁矿石热力破碎法与普通破碎法 的破碎效率。 该论文有图 51 幅，表 17 个，参考文献 126 篇。 关键词关键词球磨机；研磨介质；运动特性；热传导；热力破碎法 万方数据 II Abstract Ball mill is the key milling device, which is wildly used in metallurgy, mineral processing and chemical industry etc. The total amount of material grinded by ball mill is as high as several billion tons per year and its electrical consumption accounts for 2-5 of the total electricity in our country. The function of the ball mill was to grind and break the ore particles into the required size distribution. However, the effective breakage energy only accounts for 0.5-1 of the energy in ball mill that leads to a lower milling efficiency and greater energy consumption. This paper was supported by the National Natural Science Foundation of China, which studied the motion characteristics of grinding media, the discrete heat transfer and the particle thermal-breakage characteristics in ball mill. Understating the energy loss and the particle thermal-breakage characteristics in the milling processes can be helpful to provide the theoretical basis for improving milling efficiency and reducing energy loss. Firstly, based on the kinematics theory of grinding media, the load behavior of the grinding media was studied and which can be provided the theoretical research for the grinding media motion characteristics. Combined with the experiment and the numerical simulation, the variation of the mill parameter such as mill speed, ball filling and lifter angle on the load behavior was analyzed. Besides, this paper constructed a mathematical model that can predict the load behavior of the grinding media. Then, based on the theory of particle breakage, the energy transfer rate of particle breakage was analyzed, the discrete heat transfer model was constructed, and the variation of the heat transfer phenomenon and temperature rise at different milling parameters were studied and analyzed. Finally, based on the nonlinear population balance model, the iron ore breakage experiments were carried out and studied the variation of the breakage rate and the particle size distribution at different feed particle sizes and temperatures. Moreover, this paper analyzed the relationship between charge motion and breakage regime, and compared the thermal-breakage and general-breakage . Keywords Ball mill; Grinding media; Motion characteristics; Heat transfer; Thermal breakage 万方数据 III 目目 录录 摘摘 要要............................................................................................................................ I 目目 录录......................................................................................................................... III 图清单图清单........................................................................................................................ VII 表清单表清单........................................................................................................................... X 变量注释表变量注释表 ................................................................................................................ XI 1 绪论绪论............................................................................................................................ 1 1.1 选题背景及意义 .................................................................................................... 1 1.2 国内外研究现状 .................................................................................................... 2 1.3 存在的问题和不足 ................................................................................................ 6 1.4 研究内容与研究目标 ............................................................................................ 7 1.5 课题来源 ................................................................................................................ 8 1.6 本章小结 ................................................................................................................ 8 2 研磨介质运动形态研究研磨介质运动形态研究 ........................................................................................... 9 2.1 研磨介质运动理论分析 ........................................................................................ 9 2.2 研磨介质冲击特性 .............................................................................................. 13 2.3 实际工作过程中研磨介质的运动状态 .............................................................. 15 2.4 影响研磨介质运动规律的因素分析 .................................................................. 16 2.5 本章小结 .............................................................................................................. 23 3 研磨介质运动特性研究研磨介质运动特性研究 ......................................................................................... 24 3.1 研磨介质运动特征参数 ...................................................................................... 24 3.2 运动学实验系统 .................................................................................................. 26 3.3 研磨介质运动规律试验设计 .............................................................................. 27 3.4 研磨介质运动特征参数变化规律 ...................................................................... 30 3.5 球磨机功率分析 .................................................................................................. 42 3.6 本章小结 .............................................................................................................. 43 4 研磨介质冲击离散传热特性研究研磨介质冲击离散传热特性研究 ......................................................................... 45 4.1 球磨机冲击离散传热模型 .................................................................................. 45 4.2 球磨机转速率分析 .............................................................................................. 52 万方数据 IV 4.3 球磨机填充率分析 .............................................................................................. 54 4.4 球磨机提升条面角分析 ...................................................................................... 56 4.5 本章小结 .............................................................................................................. 57 5 铁矿石热力破碎特性研究铁矿石热力破碎特性研究 ..................................................................................... 59 5.1 总体平衡模型 ...................................................................................................... 59 5.2 矿石颗粒热力破碎试验 ...................................................................................... 62 5.3 铁矿石颗粒热力破碎法破碎特性研究 .............................................................. 66 5.4 热力破碎效率与输入能量 .................................................................................. 71 5.5 本章小结 .............................................................................................................. 72 6 总结与展望总结与展望 ............................................................................................................. 73 6.1 结论 ...................................................................................................................... 73 6.2 创新点 .................................................................................................................. 74 6.3 展望 ...................................................................................................................... 74 参考文献参考文献 ..................................................................................................................... 75 作者简历作者简历 ..................................................................................................................... 83 学位论文原创性声明学位论文原创性声明 ................................................................................................. 84 学位论文数据集学位论文数据集 ......................................................................................................... 85 万方数据 V Contents Abstract ........................................................................................................................ II Contents ....................................................................................................................... V List of Figures ........................................................................................................... VII List of Tables ................................................................................................................ X List of Variables ......................................................................................................... XI 1 Introduction ............................................................................................................... 1 1.1 Background Topics and Significance ....................................................................... 1 1.2 Domestic and Foreign Research Status ................................................................... 2 1.3 Existing Problems and Deficiencies ........................................................................ 6 1.4 Main Contents and Objects ...................................................................................... 7 1.5 Origin of Dissertation .............................................................................................. 8 1.6 Summary .................................................................................................................. 8 2 Study on the Motion Morphology of Grinding Media .......................................... 9 2.1 Motion Theoretical Analysis of Grinding Media ..................................................... 9 2.2 Impact Properties of Grinding Media .................................................................... 13 2.3 The Motion State of the Grinding Media during Actual Work .............................. 15 2.4 Analysis of Factors Affecting the Motion Law of Grinding Media ....................... 16 2.5 Summary ................................................................................................................ 23 3 Study on the Motion Characteristics of Grinding Media ................................... 24 3.1 Characteristic Parameters of Grinding Media Motion ........................................... 24 3.2 Kinematics Experiment System ............................................................................. 26 3.3 Experimental Design of Grinding Media Motion Law .......................................... 27 3.4 Variation Law of Motion Characteristic Parameters of Grinding Media ............... 30 3.5 Power Analysis of Ball Mill ................................................................................... 42 3.6 Summary ................................................................................................................ 43 4 Study on Discrete Heat Transfer Characteristics of Impact in Grinding Media ...................................................................................................................................... 45 4.1 Discrete Element Modeling of Impact Heat Conduction of Ball Mills ................. 45 4.2 Speeds Analysis of Ball Mill ................................................................................. 52 4.3 Filling Analysis of Ball Mill .................................................................................. 54 万方数据 VI 4.4 Face Angle Analysis of Lifter in Ball Mill ............................................................ 56 4.5 Summary ................................................................................................................ 57 5 Study on Thermal Fragmentation Characteristics of Iron Ore ......................... 59 5.1 Population Balance Model ..................................................................................... 59 5.2 Thermal Breakage Test of Ore Particles ................................................................ 62 5.3 Study on Breakage Characteristics of Iron Ore Particles by Thermal Breakage ... 66 5.4 Thermal Breakage Efficiency and Energy .................................................... 71 5.5 Summary ................................................................................................................ 72 6 Summary and Prospects ......................................................................................... 73 6.1 Conclusion ............................................................................................................. 73 6.2 Innovations ............................................................................................................. 74 6.3 Research Prospects ................................................................................................ 74 Reference..................................................................................................................... 75 Author’s Resume ........................................................................................................ 83 Declaration of Thesis Originality....................