关键词: 赤铁矿石, 粗粒干选, 高梯度强磁选, 正浮选

Abstract: An iron ore from Sichuan province belongs to an acid，low-magnetic iron ore with low sulfur and phosphorus，high silicon and aluminium，and iron mainly exists in the form of hematite. In order to provide a basis for developing and utilizing the ore，beneficiation tests were carried out through the process of dry high intensity magnetic separation for coarse particles-high gradient high intensity magnetic separation for fine particles-middlings back into flotation process. The results showed that after crushing and screening，the ore was divided into two sections，namely 40~15 mm and -15 mm. Iron concentrate with yield of 20.42%，iron grade of 52.67%，iron recovery of 22.47% was obtained for dealing with 40~15 mm ores through dry high intensity magnetic separation by YCG-350×1000 permanent magnetic roller separator; Iron concentrate with iron grade of 60.35%，iron recovery of 32.46% was obtained for dealing with -15 mm fraction and tailings from dry separation through grinding at 85% passing 0.074 mm through the process of one roughing，one cleaning，one scavenging with SLon high gradient magnetic separator; Iron concentrate with iron grade of 60.39% and iron recovery of 13.11% was received by dealing with middlings of high gradient magnetic separation through the process of one roughing，two cleaning direct flotation，with fatty acid NZ as collector，which makes comprehensive iron recovery rate reach 68.04%.

Key words: Hematite, Separation at coarse particles, High gradient high intensity magnetic separation, Direct flotation