Abstract: High-gradient magnetic separation (HGMS) is a key technology for processing weakly magnetic mineral resources,
offering advantages such as high throughput and effective tailing discarding,yet it suffers from limited separation precision
and selectivity. To address these limitations,coupling high-gradient magnetic fields with additional force fields (e. g. ,hydrodynamic,
vibrational,or centrifugal) to form a composite force field separation mode has emerged as an effective strategy for
enhancing separation efficiency and selectivity. This paper aims to provide a systematic review of the developments and research
status of composite force field HGMS technology over the past two decades. Firstly,focusing on three core coupling modes:magneto-
hydrodynamic,magneto-vibrational,and magneto-centrifugal,the paper delves into their underlying strengthening mechanisms
(e. g. ,utilizing pulsating inertial force to reduce mechanical entrainment,employing vibration to disrupt magnetic agglomeration)
and summarizes the optimization principles for key operational parameters. Secondly,it reviews the progress in numerical
simulation technologies,such as FEM and CFD-DEM,for multi-field coupling analysis,equipment optimization,and visualization
of microscopic separation mechanisms. By integrating specific application cases (e. g. ,the separation of low-grade iron
ore and fine-grained copper-molybdenum ore,and iron recovery from red mud,with recovery rates exceeding 37%-40%),
this paper illustrates the industrial application potential of the technology. Finally,based on a synthesis of existing achievements,
current challenges are identified,including the quantitative characterization of composite field coupling mechanisms,the
scaling-up and intellectualization of equipment,and the development of green,low-carbon processes. Future development directions
in secondary resource recovery and environmental protection are also prospected.