关键词: 高磷鲕状赤铁矿, 直接还原, 粉末还原铁, 电炉炼钢

Abstract: A high-phosphorus oolitic hematite from abroad was used as a research object for dephosphorization. The iron grade and phosphorus content of the high-phosphorus oolitic hematite were 55.81% and 0.72% respectively.48.61% phosphorus was present in the phosphate and 47.22% is present in the iron minerals. The effects of dephosphorization agent dosage， straw carbon dosage， reduction temperature and reduction time on the indexes of powdery reduced iron were studied. The results showed that the qualified indexes could not be obtained without additives. In the case of calcium carbonate dosage of 25%， straw carbon dosage of 12.5%， reduction temperature of 1 200 ℃， reduction time of 75 min， two sections of grinding and two sections of magnetic separation， iron grade， iron recovery and phosphorus content of 94.27%， 87.34% and 0.077% powdery reduced iron can be obtained respectively， which can be used as high quality raw material for electric furnace steelmaking. When no additives were added， some phosphorus-containing minerals were reduced to elemental phosphorus and enter the metal iron. Therefore， the phosphorus content in powdery reduced iron is high. When the amount of calcium carbonate added was 25%， the reduction of the phosphorus-containing mineral was inhibited and remains in the gangue phase， which can achieve the purpose of phosphorus removal. When the reduction time was too long， the phosphorus was still in the gangue phases， and the iron particles would partially encapsulate the phosphorus-containing minerals， and the grinding was difficult to separate， resulting in an increase in phosphorus content.

Key words: High-phosphorus oolitic hematite, Direct reduction, Powdery reduced iron, Electric furnace steelmaking