Abstract: In order to explore the effects of the types and dosage of dephosphorization agents and roasting temperature on the grinding characteristics of the reduction products of high- phosphorus oolitic hematite from Algeria, the grindability of the reduction products and the distribution of iron and phosphorus after grinding were studied by means of screening analysis, chemical analysis and scanning electron microscopy. The results showed that: ① The particle size of the reduction products is mainly distributed in +0.074 mm and -0.030 mm, and the yield of -0.074+0.045 mm and -0.045+0.030 mm is small. ② The grindability of the reduction product increased with the increase of the dosage of dephosphorization agents. The effects degree of different dephosphorization agents on the grindability of reduction products were CaCO3+Na2CO3, CaCO3, CaCO3+CaF2, CaF2 and Na2CO3 in descending order. ③ Phosphorus in the production above 0.074 mm mainly exists in apatite and part of iron without dephosphorization agents. The distribution of phosphorus is more concentrated, mainly in the form of apatite with CaCO3 or mixed dephosphorization agents. The distribution of phosphorus is more uniform and exists in gangue as aggregate with iron when Na2CO3 is regarded as dephosphorization agent. The phosphorus is evenly distributed and exists in gangue and iron and the dephosphorization effect is poor with CaF2. ④ The yield of +0.074 mm grain increased, the other grain yield gradually decreased, and the grindability of the reduction product decreased rapidly with the increase of roasting temperature. The iron grade and phosphorus contents in +0.074 mm grain increased, and iron and phosphorus gradually enriched into coarse grain with the increase of roasting temperature.

Key words: high phosphorus oolitic hematite, reduction roasting, dephosphorization agent type and dosage, roasting temperature, distribution of iron and phosphorus