Behavior of Fe and P during reduction magnetic roasting-separation of phosphorus-rich oolitic hematite

Fe–P separation and the behaviors of Fe and P in separation process of high-phosphorus oolitic hematite ore from western Hubei province in China were studied. Various parameters, including reducing temperature and time, dosage of the pulverized coal, grinding fineness of magnetic separation feed, magnetic field intensity and grinding fineness of flotation feed were investigated. Experimental results show that the iron concentrate with total iron grade of 61.78% and phosphorus content of 0.23% was obtained from an oolitic hematite ore containing 47.71% iron and 0.874% phosphorus by magnetization roasting-magnetic separation-reverse flotation separation process under the proper conditions. In the magnetization roasting process, the Fe and P grade was rising by 1.30% and 11.49%, respectively; the forms of Fe and P are oolite hematite (magnetite) and collophanite which mainly distributed inside oolite structure and a small portion being distributed in other shapes. In the magnetic separation process, the Fe is from 48.33% to 58.52%, and P grade was slipped to 0.70% from 0.97%, however, the forms of Fe and P have no change compared with the roasted ore. In the reverse flotation separation process, Fe is from 58.52% to 61.78%, phosphorus is from 0.70% to 0.23%, the flotation concentrate mainly contained fine iron mineral and phosphorus is finely disseminated inside the iron mineral.