关键词: 还原焙烧, 弱磁选, 强磁选, 反浮选, 资源综合利用

Abstract: In order to develop an economical and reasonable beneficiation process and provide theo⁃ retical support for industrial application，a systematic process mineralogy diagnosis and multi-path benefi⁃ ciation test are carried out to solve the problem of difficult separation of a refractory iron oxide ore due to its poor，fine and miscellaneous characteristics.Through comprehensive chemical multi-element analysis， mineral composition identification，process mineralogy and element occurrence state research，the basic characteristics of low grade，fine particle dispersion and complex composition of ore are clarified. On this basis，the core idea of“grading separation and taking measures according to theparticle-size”is put for⁃ ward.The combined process of reduction roasting-stage grinding-multi-stage low intensity magnetic separa⁃ tion-reverse flotation desilication is adopted for + 15 mm lump ore，and the simplified process of direct grinding-high intensity magnetic roughing + scavenging is adopted for - 15 mm powder ore.After roasting and magnetization of the lump ore，the magnetic properties of iron minerals are significantly enhanced. By optimizing the grinding fineness and magnetic separation process，low-intensity magnetic separation rough concentrate with iron grade of 54.26% and iron recovery of 90.93% can be obtained.The rough concentrate is subjected to reverse flotation to reduce silicon. Under the reagent system of collector YG-328B dosage of 120 g/t and starch dosage of 300 g/t，the final concentrate iron grade can reach 60.10%，the SiO2 content is reduced to 6.90%，and the iron recovery rate is 80.68%. It effectively realizes the resource utilization of this kind of refractory iron oxide ore，and provides a feasible technical way for the industrial development and utilization of similar iron ore.

Key words: reduction roasting, low intensity magnetic separation, high intensity magnetic separa? tion, reverse flotation, comprehensive utilization of resources