Mineralogy characteristics and separation technologies of aluminum and iron of high-aluminum iron ores were investigated. The results show that iron minerals are hematite and goethite mainly. Major aluminum-bearing carrier minerals include independent gibbsite enwrapped by goethite as fine granules, and others exist in goethite in the form of isomorphism. Aluminosilicates disperse or symmetrically immerse inside goethite. The existential relation between iron and aluminium in the ore is very complex. Magnetic separation and magnetization roasting-magnetic separation are unable to remove aluminum effectively because they are unable to destroy the isomorphous structure of the ore. However, most of aluminum can be removed by sodium-salt-added roasting followed by leaching processing. The iron concentrate bearing 62.84% TFe, 2.33% A1_2O_3 and 0.45% SiO_2 can be obtained by processing a limonite ore with 48.92% TFe, 8.16% A1_2O_3 and 4.24% SiO_2, and the iron recovery reaches 98.56%.