Dry　medium-intensity　magnetic　separator　(DMIMS)　plays　a　vital　role　in　enhancing　the　separation　of　low-grade　raw　magnetite　ore.　A　good　understanding　of　the　dynamic　separation　process　of　DMIMS　would　further　boost　its　economic　competitiveness　in　minerals　processing　and　engineering.　Herein,　this　study　analyzed　the　basic　structure　and　simulated　the　dynamic　separation　process　of　DMIMS　in　detail　using　CT4050　magnetic　separator　as　an　example.　Forces　(e.g.,　magnetic　force,　magnetic　particle-particle　attraction　and　gravity)　acting　on　magnetic　ore　bulks　in　multi-physical　fields　have　been　systematically　investigated　to　deepen　the　understanding　for　the　dynamic　behavior　of　magnetic　ore　bulks　based　on　elaborate　experiments　and　dynamic　simulation　using　the　finite　element　method　(FEM).　Results　show　that　the　realistic　movement　trajectory　of　isolated　magnetic　ore　bulks　can　be　well　predicated　using　dynamics　simulation.　Force　analysis　demonstrates　that　the　size　significantly　affects　the　forces　acting　on　magnetic　ore　bulks.　The　magnetic　permeability　of　bulks　not　only　determines　their　movement　trajectory　just　as　the　speed　of　conveyor　belt　does,　but　also　is　vital　in　improving　the　separation　efficiency.　Whereas,　the　shape,　size　and　rotation　angle　of　bulks　demonstrate　negligible　influence　on　their　movement　trajectory　and　separation　efficiency.　This　study　could　provide　theoretical　insights　for　optimizing　the　magnetic　separation　process　and　designing　high-performance　DMIMS.　©　2021　Elsevier　Ltd