Production of Low-Phosphorus Molten Iron from High-Phosphorus Oolitic Hematite Using Biomass Char

Abstract

In this study, an energy-saving and environmentally friendly method to produce low-phosphorus molten iron from high-phosphorus oolitic hematite was experimentally investigated and theoretically analyzed. The results indicate that biomass char is a suitable reducing agent for the proposed method. In the direct reduction stage, the ore–char briquette reached a metallization degree of 80–82% and a residual carbon content of 0.1–0.3 mass%. Under the optimized condition, phosphorus remained in the gangue as calcium phosphate. In the melting separation stage, phosphorus content ([%P]) in molten iron could be controlled by introducing a Na2CO3 additive, and the phosphorus behavior could be predicted using ion molecular coexistence theory. Molten iron with [%P] less than 0.3 mass% was obtained from the metallic briquettes with the aforementioned quality by introducing 2–4% Na2CO3 and the iron recovery rate was 75–78%.