充填尾砂颗粒干扰沉降过程实验研究
|
摘要
尾砂浓密作为充填料浆制备的关键工序是目前研究的热点,并已经取得了包括尾砂仓浓密机理,絮凝剂选择方法在内的多种实践性研究成果。但该工序中所涉及的充填尾砂颗粒"干扰沉降"过程的机理研究却相对滞后,缺乏相应的经验或理论计算模型,已经成为制约不同级配尾砂高效浓缩、稳态造浆与精准过程控制的技术瓶颈。因此,探索尾砂颗粒"干扰沉降"过程的特征,在总结与综述国内外具有代表性的干扰沉降相关理论基础上,利用某矿山经分级处理后的分级尾砂与溢流细砂为原料,开展了多种配比尾砂浆的干扰沉降实验,并依据Kynch理论,对实验数据进行拟合处理,在此基础上分析论证了Richardson-Zaki均匀干扰沉降与Selim非均匀干扰沉降理论在研究充填尾砂颗粒沉降过程时的适用性。研究结果表明:基于Richardson-Zaki理论计算的尾砂颗粒均匀干扰沉降速率值与实验实测结果相吻合,两者的相关性可决系数达0. 87,且残差值无明显规律,验证了其对尾砂颗粒均匀干扰沉降速率计算的适用性。基于Selim理论所得计算结果较均匀干扰沉降理论计算值更接近实验中尾砂浆非均匀干扰沉降的实测值,从而证明该理论能够反映尾砂颗粒非均匀干扰沉降中因不同粒径颗粒相互作用而降低了各自的沉降速率的特性,能够为尾砂浓密工程实践提供参考。同时,通过分析,为进一步阐明尾砂颗粒干扰沉降机理,将继续对尾砂级配对干扰沉降的影响及其定量化表征以及粗细颗粒相互作用的机理等问题进行深入研究。
As a key procedure of preparation of backfill slurry,the tailings thickening has hence been treated as a research focus. Many practical results including the thickening mechanism of tailings tank and principles of selection of flocculants have already been obtained. However,the mechanism studies of the hindered settling of tailing particles have been lagged,resulting in lacking empirical or theoretical calculation models,which will restrict the high efficient thickening of tailings and the precise control of preparation of different tailings slurries. Therefore,to further study the insuffi-cient aspects of aforementioned researches and to gain the features of the hindered settling of backfill tailing par-ticles,by using the classified and fine tailings from a real mine,the hindered settling experiments with the different contents of tailings and concentrations have been carried out. Based on Kynch theory,the experimental results have been fitted to describe and demonstrate the applicability of Richardson-Zaki theory and Selim theory in calculating the hindered and polydisperse settling of tailing particles. The fitted results show that the R-square figure between the calculated settling rates based on Richardson-Zaki theory and the experimental results is over 0.87 and there is no obvious relations among the residual errors,which proves the applicability of Richardson-Zaki theory. Comparing to the values calculated through Richardson-Zaki theory,the results based on Selim theory are closer to the real ones of polydisperse settling,which means Selim theory can represent some features of polydisperse settling,namely the velocity decrease features caused by the interactions of tailing particles and can be utilized as a reference in tailings thickening.Furthermore,to clearly explain the mechanism of hindered settling process,the effects of PSD of tailings on hindered settling and its mathematical expression and the mechanism of interactions between coarse and fine tailings in this process will be studied in the future.
As a key procedure of preparation of backfill slurry,the tailings thickening has hence been treated as a research focus. Many practical results including the thickening mechanism of tailings tank and principles of selection of flocculants have already been obtained. However,the mechanism studies of the hindered settling of tailing particles have been lagged,resulting in lacking empirical or theoretical calculation models,which will restrict the high efficient thickening of tailings and the precise control of preparation of different tailings slurries. Therefore,to further study the insuffi-cient aspects of aforementioned researches and to gain the features of the hindered settling of backfill tailing par-ticles,by using the classified and fine tailings from a real mine,the hindered settling experiments with the different contents of tailings and concentrations have been carried out. Based on Kynch theory,the experimental results have been fitted to describe and demonstrate the applicability of Richardson-Zaki theory and Selim theory in calculating the hindered and polydisperse settling of tailing particles. The fitted results show that the R-square figure between the calculated settling rates based on Richardson-Zaki theory and the experimental results is over 0.87 and there is no obvious relations among the residual errors,which proves the applicability of Richardson-Zaki theory. Comparing to the values calculated through Richardson-Zaki theory,the results based on Selim theory are closer to the real ones of polydisperse settling,which means Selim theory can represent some features of polydisperse settling,namely the velocity decrease features caused by the interactions of tailing particles and can be utilized as a reference in tailings thickening.Furthermore,to clearly explain the mechanism of hindered settling process,the effects of PSD of tailings on hindered settling and its mathematical expression and the mechanism of interactions between coarse and fine tailings in this process will be studied in the future.
引文
[1]杨小聪,郭利杰,许文远,等.尾矿和废石综合利用技术[M].北京:化学工业出版社,2018:1-3.
[2]尹光志,敬小非,魏作安,等.尾矿坝溃坝相似模拟试验研究[J].岩石力学与工程学报,2010,29(S2):3830-3838.YIN Guangzhi,JING Xiaofei,WEI Zuoan,et al.Experimental study of similar simulation of tailings dam-break[J].Chinese Journal of Rock Mechanics and Engineering,2010,29(S2):3830-3838.
[3]梅国栋,吴宗之.尾矿库溃坝风险定量评价方法探讨[J].中国安全生产科学技术,2012,8(2):78-82.MEI Guodong,WU Zongzhi.Discussion on quantitative assessment method of dam failure risks in tailings dam[J].Journal of Safety Science and Technology,2012,8(2):78-82.
[4]黄玉诚.矿山充填理论与技术[M].北京:冶金工业出版社,2014:7-9.
[5]史秀志,胡海燕,杜向红,等.立式砂仓尾砂浆液絮凝沉降试验研究[J].矿冶工程,2010,30(3):1-3.SHI Xiuzhi,HU Haiyan,DU Xianghong,et al.Experimental study on flocculating sedimentation of tailings slurry in a vertical sand tank[J].Mining and Metallurgical Engineering,2010,30(3):1-3.
[6]王洪江,王勇,吴爱祥,等.细粒全尾动态压密与静态压密机理[J].工程科学学报,2013,35(5):566-571.WANG Hongjiang,WANG Yong,WU Aixiang,et al.Dynamic compaction and static compaction mechanism of fine unclassified tailings[J].Chinese Journal of Engineering,2013,35(5):566-571.
[7]焦华喆,王洪江,吴爱祥,等.全尾砂絮凝沉降规律及其机理[J].工程科学学报,2010,32(6):702-707.JIAO Huazhe,WANG Hongjiang,WU Aixiang,et al.Rule and mechanism of flocculation sedimentation of unclassified tailings[J].Chinese Journal of Engineering,2010,32(6):702-707.
[8]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.
[9]郭亚兵,胡钰贤,王守信.沉降-浓缩理论及数学模型[M].北京:化学工业出版社,2014:9-10.
[10]BUSTOS M C,TORY E M,BüRGER,et al.Sedimentation and thickening:Phenomenological foundation and mathematical theory(Vol.8)[M].New York:Springer Science and Business Media,1999:27-29.
[11]KYNCH G J.A theory of sedimentation[J].Transactions of the Faraday Society,1952,48(2):166-176.
[12]RICHARDSON J F,ZAKI W N.Sedimentation and fluidization:Part I[J].Transactions of the Institution of Chemical Engineers.1954,32:35-53.
[13]BATCHELOR G K.Sedimentation in a dilute dispersion of spheres[J].Journal of Fluid Mechanics,1972,52(2):245-268.
[14]BARNEA E,MIZRAHI J.A generalized approach to the fluid dynamics of particulate systems:Part 1.General correlation for fluidization and sedimentation in solid multiparticle systems[J].Chemical Engineering Journal,1973,5(2):171-189.
[15]SELIM M S,KOTHARI A C,TURIAN R M.Sedimentation of multisized particles in concentrated suspensions[J].AIChE Journal,1983,29(6):1029-1038.
[16]SMITH T N.Differential sedimentation of particles of two different species[J].Transactions of the Institution of Chemical Engineer,1965,43(3):69-73.
[17]MASLIYAH J H.Hindered settling in a multi-species particles system[J].Chemical Engineering Science,1979,34(9):1166-1168.
[18]GB/T 50123-1999,土工试验方法标[S].
[19]JTG E42-2005,公路工程集料试验规程[S].
[20]HAPPEL J,BRENNER H.Low Reynolds number hydrodynamics:With special applications to particulate media[M].New York:Springer Science and Business Media,2012:3-10.
[2]尹光志,敬小非,魏作安,等.尾矿坝溃坝相似模拟试验研究[J].岩石力学与工程学报,2010,29(S2):3830-3838.YIN Guangzhi,JING Xiaofei,WEI Zuoan,et al.Experimental study of similar simulation of tailings dam-break[J].Chinese Journal of Rock Mechanics and Engineering,2010,29(S2):3830-3838.
[3]梅国栋,吴宗之.尾矿库溃坝风险定量评价方法探讨[J].中国安全生产科学技术,2012,8(2):78-82.MEI Guodong,WU Zongzhi.Discussion on quantitative assessment method of dam failure risks in tailings dam[J].Journal of Safety Science and Technology,2012,8(2):78-82.
[4]黄玉诚.矿山充填理论与技术[M].北京:冶金工业出版社,2014:7-9.
[5]史秀志,胡海燕,杜向红,等.立式砂仓尾砂浆液絮凝沉降试验研究[J].矿冶工程,2010,30(3):1-3.SHI Xiuzhi,HU Haiyan,DU Xianghong,et al.Experimental study on flocculating sedimentation of tailings slurry in a vertical sand tank[J].Mining and Metallurgical Engineering,2010,30(3):1-3.
[6]王洪江,王勇,吴爱祥,等.细粒全尾动态压密与静态压密机理[J].工程科学学报,2013,35(5):566-571.WANG Hongjiang,WANG Yong,WU Aixiang,et al.Dynamic compaction and static compaction mechanism of fine unclassified tailings[J].Chinese Journal of Engineering,2013,35(5):566-571.
[7]焦华喆,王洪江,吴爱祥,等.全尾砂絮凝沉降规律及其机理[J].工程科学学报,2010,32(6):702-707.JIAO Huazhe,WANG Hongjiang,WU Aixiang,et al.Rule and mechanism of flocculation sedimentation of unclassified tailings[J].Chinese Journal of Engineering,2010,32(6):702-707.
[8]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.
[9]郭亚兵,胡钰贤,王守信.沉降-浓缩理论及数学模型[M].北京:化学工业出版社,2014:9-10.
[10]BUSTOS M C,TORY E M,BüRGER,et al.Sedimentation and thickening:Phenomenological foundation and mathematical theory(Vol.8)[M].New York:Springer Science and Business Media,1999:27-29.
[11]KYNCH G J.A theory of sedimentation[J].Transactions of the Faraday Society,1952,48(2):166-176.
[12]RICHARDSON J F,ZAKI W N.Sedimentation and fluidization:Part I[J].Transactions of the Institution of Chemical Engineers.1954,32:35-53.
[13]BATCHELOR G K.Sedimentation in a dilute dispersion of spheres[J].Journal of Fluid Mechanics,1972,52(2):245-268.
[14]BARNEA E,MIZRAHI J.A generalized approach to the fluid dynamics of particulate systems:Part 1.General correlation for fluidization and sedimentation in solid multiparticle systems[J].Chemical Engineering Journal,1973,5(2):171-189.
[15]SELIM M S,KOTHARI A C,TURIAN R M.Sedimentation of multisized particles in concentrated suspensions[J].AIChE Journal,1983,29(6):1029-1038.
[16]SMITH T N.Differential sedimentation of particles of two different species[J].Transactions of the Institution of Chemical Engineer,1965,43(3):69-73.
[17]MASLIYAH J H.Hindered settling in a multi-species particles system[J].Chemical Engineering Science,1979,34(9):1166-1168.
[18]GB/T 50123-1999,土工试验方法标[S].
[19]JTG E42-2005,公路工程集料试验规程[S].
[20]HAPPEL J,BRENNER H.Low Reynolds number hydrodynamics:With special applications to particulate media[M].New York:Springer Science and Business Media,2012:3-10.