Gasification Removal Behaviour of Phosphorus Compounds from High-Phosphorous Iron Ore

The gasification removal behaviour of phosphorus from high-phosphorus iron ore is theoretically and experimentally studied in the temperature range of 400–900 °C under H₂ reducing and N₂ atmospheres. In the first step, thermodynamic analysis is conducted to reveal the gasification and reaction behaviours of common phosphorus compounds, namely P₄O₁₀, FePO₄, AlPO₄, Ca₂P₂O₇, and Ca₃(PO₄)₂. The results indicate that P₄O₁₀, FePO₄, and AlPO₄ under H₂ reducing atmosphere and P₄O₁₀ under a N₂ atmosphere can be removed by gasification, and the influence of the interaction between the vaporized gases and iron ore should be investigated. Therefore, dephosphorization experiments are performed on simulated iron ores containing P₄O₁₀, FePO₄, or AlPO₄. For the sample containing P₄O₁₀, ferric phosphates and iron phosphides are formed under the N₂ and H₂ reducing atmospheres, respectively, and their formation rates decreases with decreasing temperature, becoming almost stagnant at 400 °C. Moreover, it is confirmed that FePO₄ and AlPO₄ cannot be removed even when pure H₂ is introduced.