Study on the characteristics and re-concentration process ofthe reverse flotation tailings from Qidashan iron ore

The physicochemical characteristics of the reverse flotation tailings of Qidashan iron ore, including chemical and mineral phase composition, particle size distribution, and mineralogical characteristics were investigated systematically, by the usage of X-ray diffraction, chemical element, particle size distribution and microscope technology.Additionally, re-concentration of the tailings was studied.The results showed that the valuable mineral in the tailings was hematite, which was mainly distributed in the fine fractions, while the main gangue mineral was quartz.The process containing desliming, screening, gravity concentration, magnetic separation followed by reverse flotation was adoptedto recycle valuable mineral of the tailings.And the concentrate with iron grade of 65.48% and recovery of 16.88% was collected after the progress of desliming, screening, and gravity concentrationby the usage of spiral.Magnetic separation concentrate with iron grade of 30.45% and recovery of 54.51% was fed into reverse flotation.The NaOH, starch, CaO and LYK were chosen as the regulator, depressant, activator and collector, respectively.Reverse flotation concentrate with iron grade of 65.36% and recovery up to 31.04% could be obtained after one roughing and two cleaning stages.As a result, iron minerals were recycled effectively from the reverse flotation tailings of Qidashan iron ore.