基于泥层高度的耙架扭矩力学模型及机理分析
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摘要
通过进行不同泥层高度下的连续动态浓密实验,得到压密区尾砂浆的质量分数和屈服应力的变化规律;借助屈服应力与泥层高度的回归关系,并对浓密机耙架进行力学分析,建立不同泥层高度下的耙架扭矩力学模型。研究结果表明:耙架扭矩随泥层高度的变化规律可以分为缓慢—强化—线性3个阶段。结合压密区砂浆存在形式的变化,发现随着泥层高度的增加,压密区尾砂颗粒受到的压力增大,砂浆密度提高并逐渐致密化,导致耙架扭矩在不同阶段内增长规律不同。通过采用扫描电镜观测压密区尾砂浆的微观结构,发现3个阶段内,絮团发生沉积—致密—稳定3种不同形式的变化,并伴随着絮团尺寸的改变,从而最终提高了浓密机耙架扭矩,进一步验证了耙架扭矩力学模型。
Through continuous and dynamic thickening experiments at different sludge heights, the change law of the concentration and yield stress of the slurry in the compaction zone was obtained; Based on regression analysis of yield stress and sludge height and mechanical analysis of rake frame, the mechanical model of rake torque with different sludge heights was established. The results show that with the increase of sludge height, the change law of rake torque can be divided into 3 stages: slow stage, strengthening stage and linear stage. The change of the existing form of slurry in compaction area shows that with the increase of sludge height, the pressure of tailings particles increases, and the density of slurry increases and slurry is gradually densified, resulting in different growth rules of rake torque at different stages.Through observing the microstructure of the slurry in compaction area by using scanning electron microscope, it is found that in the 3 phases, flocs change in three different forms: sedimentation, densification and stability. With the change of floc size, the rake torque is ultimately improved, which verifies the mechanical model of rake torque.
Through continuous and dynamic thickening experiments at different sludge heights, the change law of the concentration and yield stress of the slurry in the compaction zone was obtained; Based on regression analysis of yield stress and sludge height and mechanical analysis of rake frame, the mechanical model of rake torque with different sludge heights was established. The results show that with the increase of sludge height, the change law of rake torque can be divided into 3 stages: slow stage, strengthening stage and linear stage. The change of the existing form of slurry in compaction area shows that with the increase of sludge height, the pressure of tailings particles increases, and the density of slurry increases and slurry is gradually densified, resulting in different growth rules of rake torque at different stages.Through observing the microstructure of the slurry in compaction area by using scanning electron microscope, it is found that in the 3 phases, flocs change in three different forms: sedimentation, densification and stability. With the change of floc size, the rake torque is ultimately improved, which verifies the mechanical model of rake torque.
引文
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[19]高维鸿,王洪江,陈辉,等.尾矿动态浓密过程中底流浓度主要影响因素研究[J].金属矿山,2016,45(11):102-105.GAO Weihong,WANG Hongjiang,CHEN Hui,et al.Study on main factors of underflow concentration in the dynamics thickening process of tailings[J].Metal Mine,2016,45(11):102-105.
[20]尹升华,王勇.泥层高度对细粒全尾浓密规律的影响[J].科技导报,2012,30(7):29-33.YIN Shenghua,WANG Yong.Influence of mud height on the concentration of the fine tailing[J].Science&Technology Review,2012,30(7):29-33.
[21]陈述文,陈启文.HRC高压浓缩机的原理,结构及应用[J].金属矿山,2002,32(12):33-36.CHEN Shuwen,CHEN Qiwen.Principle,structure and application of HRC high pressure thickener[J].Metal Mine,2002,32(12):33-36.
[22]王勇,王洪江,吴爱祥.基于高径比的深锥浓密机底流浓度数学模型[J].武汉理工大学学报,2011,33(8):113-117.WANG Yong,WANG Hongjiang,WU Aixiang.Mathematical model of deep cone thickener underflow concentration based on the height to diameter ratio[J].Journal of Wuhan University of Technology,2011,33(8):113-117.
[23]FARROW J B,JOHNSTON R R M,SIMIC K,et al.Consolidation and aggregate densification during gravity thickening[J].Chemical Engineering Journal,2000,80(1):141-148.
[2]REID C,BECAERT V,AUBERTIN M,et al.Life cycle assessment of mine tailings management in Canada[J].Journal of Cleaner Production,2009,17(4):471-479.
[3]GüNTHERT F W.Thickening zone and sludge removal in circular final settling tanks[J].Water Science and Technology,1984,16(10/11):303-316.
[4]WARDEN J H.The design of rakes for continuous thickeners especially for waterworks coagulant sludges[J].Filtration&Separation,1981,18(2):113-116.
[5]GLADMAN B,DE KRETSER R G,RUDMAN M,et al.Effect of shear on particulate suspension dewatering[J].Chemical Engineering Research and Design,2005,83(7):933-936.
[6]LAKE P,BORIS M E,GOLLAHER T.High density paste thickener in Siberia[C]//Proceedings of the 13th International Seminar on Paste and Thickened Tailings.Toronto,Canada,2010:411-419.
[7]ROSART J W.Advantages of bolted tank construction for paste thickeners[C]//Proceedings of the 13th International Seminar on Paste and Thickened Tailings.Toronto,Canada,2010:403-410.
[8]FROST R C,HALLIDAY J,DEE A S.Continuous consolidation of sludge in large scale gravity thickeners[J].Water Science and Technology,1993,28(1):77-86.
[9]HONG Zhenshun,YIN Jie,CUI Yujun.Compression behaviour of reconstituted soils at high initial water contents[J].Géotechnique,2010,60(9):691-700.
[10]王勇,吴爱祥,王洪江,等.全尾膏体动态压密特性及其数学模型[J].岩土力学,2014,35(增刊):168-172.WANG Yong,WU Aixiang,WANG Hongjiang,et al.Dynamic thickening characteristics and mathematical model of total tailings[J].Rock and Soil Mechanics,2014,35(Suppl):168-172.
[11]李辉,王洪江,吴爱祥,等.基于尾砂沉降与流变特性的深锥浓密机压耙分析[J].北京科技大学学报,2013,35(12):1553-1558.LI Hui,WANG Hongjiang,WU Aixiang,et al.Pressure rake analysis of deep cone thickeners based on tailings’settlement and rheological characteristics[J].Journal of University of Science and Technology Beijing,2013,35(12):1553-1558.
[12]焦华喆,王洪江,吴爱祥,等.深锥浓密机底流流变特性实验研究[C]//中国矿业科技创新与应用技术高峰论坛.成都,2010:130-132.JIAO Huazhe,WANG Hongjiang,WU Aixaing,et al.Experiment study on the properties of underflow in deep core thickener[C]//Forum on Technological Innovation and Applied Technology of China’s Mining Industry.Chengdu,2010:130-132.
[13]郭跃久,姜磊,于勇,等.浓缩机“压耙”事故及试验的重要性[J].科技传播,2014(3):102.GUO Yuejiu,JIANG Lei,YU Yong,et al.The importance of“pressure rake”accident and test of thickener[J].Public Communication of Science&Technology,2014(3):102.
[14]王占楼.选矿厂“压耙”事故引起的思考[J].矿山机械,2007,35(10):169-169.WANG Zhanlou.The accident thinking of“pressure rake”for concentration plant[J].Mining&Processing Equipment,2007,35(10):169-169.
[15]董永胜,穆永森,齐秀英.自动报警和高压风在预防浓缩机压耙子事故中的应用[J].选煤技术,2003(5):43-44.DONG Yongsheng,MU Yongsen,QI Xiuying.Application of automatic alarm and high pressure air in the accident prevention of rake thickeners[J].Coal Preparation Technology,2003(5):43-44.
[16]RUDMAN M,SIMIC K,PATERSON D A,et al.Raking in gravity thickeners[J].International Journal of Mineral Processing,2008,86(1):114-130.
[17]吴爱祥,焦华喆,王洪江,等.深锥浓密机搅拌刮泥耙扭矩力学模型[J].中南大学学报(自然科学版),2012,43(4):1469-1474.WU Aixiang,JIAO Huazhe,WANG Hongjiang,et al.Mechanical model of scraper rake torque in deep-cone thickener[J].Journal of Central South University(Science and Technology),2012,43(4):1469-1474.
[18]王卫,杨金艳.深锥浓密机刮泥功率的确定及扩能改造功率校核[J].黄金,2014,24(1):44-46.WANG Wei,YANG Jinyan.Determination of slob-scraper output power of deep-cone thickener and the power check of capacity expansion[J].Gold,2014,24(1):44-46.
[19]高维鸿,王洪江,陈辉,等.尾矿动态浓密过程中底流浓度主要影响因素研究[J].金属矿山,2016,45(11):102-105.GAO Weihong,WANG Hongjiang,CHEN Hui,et al.Study on main factors of underflow concentration in the dynamics thickening process of tailings[J].Metal Mine,2016,45(11):102-105.
[20]尹升华,王勇.泥层高度对细粒全尾浓密规律的影响[J].科技导报,2012,30(7):29-33.YIN Shenghua,WANG Yong.Influence of mud height on the concentration of the fine tailing[J].Science&Technology Review,2012,30(7):29-33.
[21]陈述文,陈启文.HRC高压浓缩机的原理,结构及应用[J].金属矿山,2002,32(12):33-36.CHEN Shuwen,CHEN Qiwen.Principle,structure and application of HRC high pressure thickener[J].Metal Mine,2002,32(12):33-36.
[22]王勇,王洪江,吴爱祥.基于高径比的深锥浓密机底流浓度数学模型[J].武汉理工大学学报,2011,33(8):113-117.WANG Yong,WANG Hongjiang,WU Aixiang.Mathematical model of deep cone thickener underflow concentration based on the height to diameter ratio[J].Journal of Wuhan University of Technology,2011,33(8):113-117.
[23]FARROW J B,JOHNSTON R R M,SIMIC K,et al.Consolidation and aggregate densification during gravity thickening[J].Chemical Engineering Journal,2000,80(1):141-148.