Abstract: Iron distribution rate of an amphibole hematite ore in form of hernatile-limonite from Yuanjiacun Taigang Group is 90.37%，followed by ferrosilicate.Hornblende ore content is 12.60%，the susceptibility of which is a little lower than that of hematite，which brings large difficulty for magnetic separation of the ore.In order to provide technique basis on mineral processing for the ore in this type，high gradient magnetic separation properties were studied based on the process mineralogy research.By single factor conditioning test，for various grind fineness，magnetic medium size and background magnetic field strength，which have significant impact on factors of high gradient magnetic separation index，and orthogonal tests was also conducted with swivel speed，pulse frequency and rinse water as factors in three factors and three levels design.The optimum high gradient magnetic separation conditions were selected.Iron concentrate with iron grade of 44.12% and recovery of 81.66% was obtained at the grinding fineness of 85% -0.074 mm，magnetic field intensity of 796 kA/m，magnetic medium rod diameter is 2 mm，swivel speed is 2 r/min，pulse frequency is 400 times per minute，rinse water of 25 L/min.The analysis results at optimum condition show that in the process of high intensity magnetic separation，hornblende will be enriched in magnetic products for its weak magnetism is the main reason for low separation index；low liberation degree，too much interlocked particles of concentrate，and serious mechanical entrainment is the important reason for the low grade of high gradient magnetic separation.To reslizr reasonable development of the ore in this type，further research on magnetization roasting or depth reduction method should be conducted.

Key words: Amphibole type hematite, Magnetic separation, Orthogonal experiment