A method, process or system for producing an iron oxide concentrate from a treatment slurry of a low grade mineral assemblage includes mixing a flocculant with the treatment slurry and dewatering the treatment slurry before passing the treatment slurry through a wet high intensity magnetic separator of a type that employs a flux amplifying matrix (i.e., a WHIMS-FAM device) and recovering an iron oxide concentrate fraction and a tailings fraction from the WHIMS-FAM device. Another method, process or system for producing an iron oxide concentrate includes passing the treatment slurry through a WHIMS-FAM device and recovering an iron oxide concentrate fraction slurry and a tailings fraction slurry from the WHIMS-FAM device; mixing a flocculant with the concentrate fraction slurry and dewatering the concentrate slurry to provide a thickened concentrate slurry before filtering the thickened concentrate slurry to provide a concentrate filter cake.