Patent ID: 8545594

Claim:
A method of enriching the iron ore content of low grade iron bearing materials to provide a concentrate having a relatively high iron content comprising: (a) forming a slurry of particulate low grade iron bearing materials; (b) subjecting the slurry of (a) to an ultrasonic treatment to separate interfering materials, including clays, from iron ore compounds; (c) subjecting the slurry of (b) to at least one stage of low intensity magnetic separation of 800-1600 gauss to produce magnetic concentrate and a paramagnetic tail slurry fraction; (d) treating the paramagnetic tail fraction to a further ultrasonic step to separate interfering materials; and (e) treating the tail fraction to a plurality of stages of low intensity magnetic separation of 800-3000 gauss and high intensity magnetic separation of 7500-12,500 gauss to produce a concentrate of paramagnetic ores.