Enrichment of phosphorus in reduced iron during coal based reduction of high phosphorus-containing oolitic haematite ore.

With the objective of phosphorus enrichment in the metallic iron during coal-based reduction, high-phosphorus oolitic haematite ore was reduced in the presence of coal with the coal/ore molar ratio (coal/ore, the molar ratio of fixed carbon in coal to oxygen in iron oxides of ore) varying from 1.0 to 2.5 at temperatures ranging from 1 473 to 1 548 K. The metallic iron was beneficiated from reduction products by magnetic separation. The results showed that the enrichment of phosphorus in the metallic iron improved with increasing temperature and coal/ore molar ratio. The phosphorus content and the phosphorus enrichment could reach 2.5 and 77.5%, respectively, with a coal/ore molar ratio of 2.5 at 1 548 K and after 60 minute reduction. The high phosphorus-containing metallic iron so obtained could then be converted to steel and high phosphorus steelmaking slag that can be used as a phosphate fertiliser. Kinetic analysis demonstrated that the process of phosphorus enrichment in the metallic iron could be divided into two stages, early and late, described by phase boundary-controlled reaction and diffusion-controlled, respectively. The effect of reduction temperature and coal/ore molar ratio on the enrichment behaviour of phosphorus in the metallic iron during coal-based reduction of high phosphorus-containing oolitic haematite ore was studied in this paper. Furthermore, the kinetic parameters of phosphorus enrichment in the metallic iron were determined through kinetic model fitting to provide scientific understanding of phosphorus enrichment behaviour during reduction of oolitic haematite ores. This will in turn boost the utilisation of high phosphorus-containing oolitic haematite ores. (Authors.)
With the objective of phosphorus enrichment in the metallic iron during coal-based reduction, high-phosphorus oolitic haematite ore was reduced in the presence of coal with the coal/ore molar ratio (coal/ore, the molar ratio of fixed carbon in coal to oxygen in iron oxides of ore) varying from 1.0 to 2.5 at temperatures ranging from 1 473 to 1 548 K. The metallic iron was beneficiated from reduction products by magnetic separation. The results showed that the enrichment of phosphorus in the metallic iron improved with increasing temperature and coal/ore molar ratio. The phosphorus content and the phosphorus enrichment could reach 2.5 and 77.5%, respectively, with a coal/ore molar ratio of 2.5 at 1 548 K and after 60 minute reduction. The high phosphorus-containing metallic iron so obtained could then be converted to steel and high phosphorus steelmaking slag that can be used as a phosphate fertiliser. Kinetic analysis demonstrated that the process of phosphorus enrichment in the metallic iron could be divided into two stages, early and late, described by phase boundary-controlled reaction and diffusion-controlled, respectively. The effect of reduction temperature and coal/ore molar ratio on the enrichment behaviour of phosphorus in the metallic iron during coal-based reduction of high phosphorus-containing oolitic haematite ore was studied in this paper. Furthermore, the kinetic parameters of phosphorus enrichment in the metallic iron were determined through kinetic model fitting to provide scientific understanding of phosphorus enrichment behaviour during reduction of oolitic haematite ores. This will in turn boost the utilisation of high phosphorus-containing oolitic haematite ores. (Authors.)