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工程科学学报.第42卷,第10期:1308-1317.2020年10月 Chinese Journal of Engineering,Vol.42,No.10:1308-1317,October 2020 https://doi.org/10.13374/j.issn2095-9389.2019.10.19.002;http://cje.ustb.edu.cn 时间-速率双因素下全尾砂膏体的屈服应力易变行为 李翠平2),颜丙恒,2)四,王少勇12),侯贺子1,2),陈格仲12) 1)北京科技大学土木与资源工程学院.北京1000832)金属矿山高效开采与安全教有部重点实验室,北京100083 ☒通信作者,E-mail:ybh19920509@126.com 摘要以往对全尾砂膏体屈服应力的研究局限于理想屈服应力流体框架内,认为一定材料配比条件下,膏体的屈服应力是 确定的,即认为屈服应力是膏体料浆固有的一个物理属性值.通过开展不同质量分数全尾砂膏体屈服应力测量实验,分析了 测量速率与测量时间对不同浓度膏体屈服应力的影响,发现屈服应力值的大小与测量过程相关.对比分析峰值屈服应力、动 态屈服应力、静态屈服应力,发现全尾砂膏体屈服应力随测量时间-测量速率在一定条件下的变化规律,即峰值屈服应力、静 态屈服应力正比于膏体的测量速率,动态屈服应力反比于测量时间,以变异系数C,评价料浆屈服应力的离散程度,其中 74%质量分数膏体动态屈服应力变异系数最大,Cvmax=-27.07%,而66%质量分数膏体静态屈服应力变异系数最小,Cmim= 233%.进而从细观层面分析了膏体屈服过程中颗粒间作用力、颗粒网络结构随测量时间-测量速率的变化规律.解释了全尾 砂膏体屈服应力易变性机理 关键词全尾砂膏体:屈服应力:测量过程:易变行为:触变性 分类号TD853 Variability behavior of yield stress for unclassified tailings pasted under measurement time-velocity double factors LI Cui-ping2).YAN Bing-heng WANG Shao-yong 2),HOU He-i2,CHEN Ge-zhong2) 1)School of Civil and Resource Engineering,University of Science and Technology Beijing,Beijing 100083,China 2)Key Laboratory of Ministry of Education of China for High-Efficient Mining and Safety of Metal Mines,Beijing 100083,China Corresponding author,E-mail:ybh19920509@126.com ABSTRACT The rake torque of deep cone thickener,pipeline resistance,and paste accumulation slope were important technological parameters for the efficient paste backfill process,which are to be solved or optimized for the practical application in mines.The yield stress of paste was considered as an important rheological parameter for solving these technological parameters.In the past,the research of yield stress of the materials for unclassified tailings paste was limited to the concept and analysis of yield stress fluids used.For example,the fluids such as Bingham fluid,H-B fluid,and Casson fluid were commonly used.When the shear stress of the paste was less than yield stress,the slurry paste remained stationary,and the paste started to flow when shear stress was greater than yield stress.So it concluded that the yield stress was an important parameter in the transition from solid state to flow state.It was considered that yield stress of paste with a certain ratio of material had a unique value,which was regarded as inherent physical property of paste.At present, most rheological studies of concentrated suspensions had found that the evolution of particle structure in suspensions resulted in thixotropy,which increased the difficulty of measuring yield stress of suspensions.Considering the unclassified tailings as specific experimental sample,experiments with different mass fractions paste were carried out and yield stresses were measured.The influence of measuring velocity and measuring time on yield stress of paste was analyzed.It is found that the yield stress value is correlated with 收稿日期:2019-10-19 基金项目:国家重点研发计划资助项目(2017YFC0602903:国家自然科学基金资助项目(51774039):北京市自然科学基金资助项目(8192029)时间–速率双因素下全尾砂膏体的屈服应力易变行为 李翠平1,2),颜丙恒1,2) 苣,王少勇1,2),侯贺子1,2),陈格仲1,2) 1) 北京科技大学土木与资源工程学院,北京 100083    2) 金属矿山高效开采与安全教育部重点实验室,北京 100083 苣通信作者,E-mail: ybh19920509@126.com 摘    要    以往对全尾砂膏体屈服应力的研究局限于理想屈服应力流体框架内,认为一定材料配比条件下,膏体的屈服应力是 确定的,即认为屈服应力是膏体料浆固有的一个物理属性值. 通过开展不同质量分数全尾砂膏体屈服应力测量实验,分析了 测量速率与测量时间对不同浓度膏体屈服应力的影响,发现屈服应力值的大小与测量过程相关. 对比分析峰值屈服应力、动 态屈服应力、静态屈服应力,发现全尾砂膏体屈服应力随测量时间–测量速率在一定条件下的变化规律,即峰值屈服应力、静 态屈服应力正比于膏体的测量速率,动态屈服应力反比于测量时间,以变异系数 Cv 评价料浆屈服应力的离散程度,其中 74% 质量分数膏体动态屈服应力变异系数最大,Cvmax=27.07%,而 66% 质量分数膏体静态屈服应力变异系数最小,Cvmin= 2.33%. 进而从细观层面分析了膏体屈服过程中颗粒间作用力、颗粒网络结构随测量时间–测量速率的变化规律,解释了全尾 砂膏体屈服应力易变性机理. 关键词    全尾砂膏体;屈服应力;测量过程;易变行为;触变性 分类号    TD853 Variability behavior of yield stress for unclassified tailings pasted under measurement time‒velocity double factors LI Cui-ping1,2) ,YAN Bing-heng1,2) 苣 ,WANG Shao-yong1,2) ,HOU He-zi1,2) ,CHEN Ge-zhong1,2) 1) School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China 2) Key Laboratory of Ministry of Education of China for High-Efficient Mining and Safety of Metal Mines, Beijing 100083, China 苣 Corresponding author, E-mail: ybh19920509@126.com ABSTRACT    The rake torque of deep cone thickener, pipeline resistance, and paste accumulation slope were important technological parameters for the efficient paste backfill process, which are to be solved or optimized for the practical application in mines. The yield stress of paste was considered as an important rheological parameter for solving these technological parameters. In the past, the research of  yield  stress  of  the  materials  for  unclassified  tailings  paste  was  limited  to  the  concept  and  analysis  of  yield  stress  fluids  used.  For example, the fluids such as Bingham fluid, H–B fluid, and Casson fluid were commonly used. When the shear stress of the paste was less than yield stress, the slurry paste remained stationary, and the paste started to flow when shear stress was greater than yield stress. So it concluded that the yield stress was an important parameter in the transition from solid state to flow state. It was considered that yield stress of paste with a certain ratio of material had a unique value, which was regarded as inherent physical property of paste. At present, most  rheological  studies  of  concentrated  suspensions  had  found  that  the  evolution  of  particle  structure  in  suspensions  resulted  in thixotropy,  which  increased  the  difficulty  of  measuring  yield  stress  of  suspensions.  Considering  the  unclassified  tailings  as  specific experimental sample, experiments with different mass fractions paste were carried out and yield stresses were measured. The influence of measuring velocity and measuring time on yield stress of paste was analyzed. It is found that the yield stress value is correlated with 收稿日期: 2019−10−19 基金项目: 国家重点研发计划资助项目 (2017YFC0602903);国家自然科学基金资助项目 (51774039);北京市自然科学基金资助项目 (8192029) 工程科学学报,第 42 卷,第 10 期:1308−1317,2020 年 10 月 Chinese Journal of Engineering, Vol. 42, No. 10: 1308−1317, October 2020 https://doi.org/10.13374/j.issn2095-9389.2019.10.19.002; http://cje.ustb.edu.cn
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