In China, iron ore with hematite grain size of less than 0.045mm or magnetite grain size of less than 0.03mm is commonly referred to as fine-grained iron ore . Yuanjiacun Iron deposit and Qidong Iron deposit in Shanxi and Hunan Province, respectively, are the most typical fine grain iron deposits in China. The Taiyuan Iron and Steel Group and scientific research units, who aimed at the Yuanjiacun iron ore recycle and conduct a large number of experimental studies. The original iron ore grade of 31.18%, −0.045mm particle size accounted for 93.81% of the total ore, they got concentrate iron grade 66.95%, and recovery rate of 72.62%. With this process, the Yuanjiacun iron deposit built a mineral processing plant with annual capacity of 22 million tons by the end of 2012 . Changsha Institute of Mining and Metallurgy proposed a selective flocculation desliming-anti-flotation technology and developed a SA-2 flocculant (for the purpose of fine grain size, complex nature of igneous iron ore in Qidong iron deposit) . At present, the Qidong iron deposit uses this technology to build a beneficiation plant with an annual treatment capacity of 2.8 million tons. Under the conditions of a raw ore grade of 28.36% and a grinding fineness of −0.038mm (98%), the concentrate iron grade 62.5%, the recovery of 68% have been achieved [18, 19, 20]. There are many examples like this. Stage grinding—stage magnetic separation likely is the best process for processing fine-grained magnetite [21, 22]; for fine-grained magnetite-hematite mixed iron ore, weak magnetic—strong magnetic—resurfacing—reverse flotation process can obtain the high recovery rate; that sorting fine particles hematite process mainly has strong magnetic—desliming—reverse flotation [23, 24], selective flocculation—reverse flotation  and strong magnetic—centrifugal beneficiation .