关键词: 赤铁矿, 菱铁矿, 悬浮焙烧, 热力学分析, 磁性分析

Abstract: Main valuable element of iron ore from Qijiang is iron，with grade of 35.47%. Iron mainly exists in form of hematite and siderite，with distribution of 45.45% and 51.11% respectively. The results of suspension roasting-low intensity magnetic separation experiment on ground products with different size show that，concentrate index is optimum when grinding fineness is -0.074 mm accounted for 50%. Suspension roasting-low intensity magnetic separation experiment was conducted on products with size of -0.074 mm accounted for 50% sieve to +0.1，0.074~0.1，0.045~0.074，-0.045 mm. Results indicate the concentrate index was relatively good when the feed particle size was 0.045~0.074 mm and 0.074~0.1 mm. The XRD and magnetism analysis on products with different particle size show that the reaction is not complete and there are still some hematite and siderite have not been reduced in reduced products for +0.1 mm fraction for too large particle size; iron minerals of reduced products for 0.074~0.1 mm and 0.045~0.074 mm fraction is mainly high intensity magnetic magnetite; over reduction performance was took place in -0.045 mm fraction，and low intensity magnetic wustite was generated. The results can provide technique basis for the optimization of the suspension roasting process of Qijiang iron ore.

Key words: Hematite ore, Siderite ore, Suspension roasting, Thermodynamic analysis, Magnetic property analysis