颗粒物质兼具固体与流体的双重复杂力学特征,其运动行为通常呈现显著的非线性、多尺度耦合及能量耗散特性,因此经典连续介质理论难以精准描述颗粒系统的内在机理。离散单元法(Discrete element method,DEM)基于牛顿第二运动定律,通过追...颗粒物质兼具固体与流体的双重复杂力学特征,其运动行为通常呈现显著的非线性、多尺度耦合及能量耗散特性,因此经典连续介质理论难以精准描述颗粒系统的内在机理。离散单元法(Discrete element method,DEM)基于牛顿第二运动定律,通过追踪颗粒的运动状态与颗粒间相互作用力,可有效捕捉颗粒的接触、碰撞及能量耗散过程,已成为连接颗粒系统微观作用机制与宏观动力学行为的重要研究手段。本文首先系统介绍了适用于颗粒流动系统的连续模型与离散模型两类经典模型,重点阐述了DEM的理论基础,并围绕颗粒系统的堆积特性与流动特性等基础科学问题展开分析;在此基础上,综述了DEM及其流固耦合方法在矿物加工与冶金领域的典型工程应用。研究表明,基于DEM的颗粒系统研究可将传统依赖经验的“黑箱式”工艺参数优化模式逐步转变为基于颗粒运动轨迹、接触行为及碰撞特征的定量化分析方法,实现从实验室尺度机理研究到工业尺度过程预测的跨尺度关联与动态模拟。颗粒物质基础理论研究与工程应用的深度融合,不仅能够深化对复杂颗粒系统动力学行为的认知,还可为流程工业的绿色化、高效化及智能化发展提供重要的理论支撑与技术基础。展开更多
The equilibrium phase relations of the CaO–SiO2–TiO2–5wt%Fe3O4system were experimentally investigated at 1400℃ in air High-temperature equilibration-quenching techniques were employed in an electric Mo...The equilibrium phase relations of the CaO–SiO2–TiO2–5wt%Fe3O4system were experimentally investigated at 1400℃ in air High-temperature equilibration-quenching techniques were employed in an electric MoSi2resistance heated furnace,with phase composition analysis conducted using an electron probe microanalyzer and X-ray diffraction.A single liquid region,liquid–solid phase equilibria regions (including liquid–tridymite,liquid–rutile,liquid–perovskite,and liquid–wollastonite),and three-phase equilibria regions of liquid–tridymite–rutile and liquid–rutile–perovskite were found.The 1400℃ isothermal sections of the CaO-SiO2-TiO2-5wt%Fe3O4system in air were projected.The present experimental results exhibited good agreement with the calculation results obtained from FactSage.展开更多
摘要颗粒物质兼具固体与流体的双重复杂力学特征,其运动行为通常呈现显著的非线性、多尺度耦合及能量耗散特性,因此经典连续介质理论难以精准描述颗粒系统的内在机理。离散单元法(Discrete element method,DEM)基于牛顿第二运动定律,通过追踪颗粒的运动状态与颗粒间相互作用力,可有效捕捉颗粒的接触、碰撞及能量耗散过程,已成为连接颗粒系统微观作用机制与宏观动力学行为的重要研究手段。本文首先系统介绍了适用于颗粒流动系统的连续模型与离散模型两类经典模型,重点阐述了DEM的理论基础,并围绕颗粒系统的堆积特性与流动特性等基础科学问题展开分析;在此基础上,综述了DEM及其流固耦合方法在矿物加工与冶金领域的典型工程应用。研究表明,基于DEM的颗粒系统研究可将传统依赖经验的“黑箱式”工艺参数优化模式逐步转变为基于颗粒运动轨迹、接触行为及碰撞特征的定量化分析方法,实现从实验室尺度机理研究到工业尺度过程预测的跨尺度关联与动态模拟。颗粒物质基础理论研究与工程应用的深度融合,不仅能够深化对复杂颗粒系统动力学行为的认知,还可为流程工业的绿色化、高效化及智能化发展提供重要的理论支撑与技术基础。
基金financially supported from the National Natural Science Foundation of China (No. 52204310)the National Key Research and Development Program of China (No. 2021YFC2901000)+4 种基金the China Postdoctoral Science Foundation (Nos. 2020TQ0059 and 2020M570967)the Natural Science Foundation of Liaoning Province, China (No. 2021-MS-083)the Fundamental Research Funds for the Central Universities, China (No. N2125010)the Open Project Program of Key Laboratory of Metallurgical Emission Reduction & Resources Recycling (Anhui University of Technology), Ministry of Education, China (No. JKF22-02)the Key Laboratory for Anisotropy and Texture of Materials, Ministry of Education, China。
摘要The equilibrium phase relations of the CaO–SiO2–TiO2–5wt%Fe3O4system were experimentally investigated at 1400℃ in air High-temperature equilibration-quenching techniques were employed in an electric MoSi2resistance heated furnace,with phase composition analysis conducted using an electron probe microanalyzer and X-ray diffraction.A single liquid region,liquid–solid phase equilibria regions (including liquid–tridymite,liquid–rutile,liquid–perovskite,and liquid–wollastonite),and three-phase equilibria regions of liquid–tridymite–rutile and liquid–rutile–perovskite were found.The 1400℃ isothermal sections of the CaO-SiO2-TiO2-5wt%Fe3O4system in air were projected.The present experimental results exhibited good agreement with the calculation results obtained from FactSage.