Abstract: The influence of roasting on the acid leaching-dephosphorization of svanbergite high phosphorous iron ore represented by that from Henan and its mechanism are studied.The result shows that roasting is of great importance to the acid leaching-dephosphorization of this kind of ore.The hard acid-soluble svanbergite will gradually decompose into hexagonal AlPO₄ which is acid-soluble at a roasting temperature of 500~700 ℃, thus greatly improving the dephosphorization effect of acid leaching.However, when the roasting temperature rises to over 1 025 ℃， the AlPO₄ crystals will change from hexagonal to cristobalite that is hard to solve in acid, leading to the decrease of dephosphorization.For this test sample, it is best to have a roasting temperature of 800 ℃, which is kept for one hour.

Key words: Svanbergite high phosphorous iron ore, Roasting, Dephosphorization by acid leaching