关键词: 菱铁矿, 流态化, 磁化焙烧, 浮氏体, 预氧化, 低温

Abstract: The contents of siderite in a high magnetic concentrate in Anshan is high， so it is difficult to achieve effective separation. Therefore， the fluidized roasting reactor was used to carry out the experimental study of low temperature pre-oxidation， ultra-low temperature reduction magnetization roasting and low magnetic separation on the basis of traditional reduction magnetization roasting. The results showed that: ① The TFe grade of the sample is 29.47%， the contents of the main gangue component SiO2 is 52.81%， and the contents of harmful impurities S and P are low. Iron mainly exists in the form of hematite with a distribution rate of 79.37%， followed by iron carbonate of 11.71% and magnetic iron of 3.46%. ② Under the conditions of 500 ℃ and 550 ℃， weakly magnetic wustite is formed in the process of direct reduction magnetization roasting with industrial producer gas as reducing gas. It is difficult to achieve complete magnetic transformation of iron mineral phase. ③ Stable and complete strong magnetic transformation could be obtained by low temperature pre-oxidation and ultra-low temperature reduction magnetization roasting. The appropriate parameters of fluidized magnetization roasting are pre-oxidation at 550 ℃ for 2.5 min and reduction roasting at 450 ℃ for 10 min. ④ Under the conditions of grinding fineness of -30 μm accounting for 92.60% and magnetic field intensity of 79.60 kA/m， a good index of iron concentrate with grade of more than 63% and recovery rate of more than 84% was obtained. ⑤ The results of XRD analysis， BSE mineral phase detection and EDS detection for the productions showed that there was no weakly magnetic hematite and wustite in the test process， the pre-oxidized ore maintained the initial shape of the phase boundary of the iron-bearing material in the original sample， and Mg and Ca elements in the siderite mineral phase through isomorphism did not migrate during the roasting process， also the process of grinding and low intensity magnetic separation couldn't achieve separation.

Key words: siderite, fluidization, magnetization roasting, wustite, preoxidation, low temperature