Research On Increasing Reverse Flotation Recovery Of Donganshan Iron Mines

The finely disseminated hematite and magnetite ore in Anshan ore are refractory to process. Since2002, the concentrating performance in Donganshan Sintering Plant has been improved to concentrate grade64%by a process of classification-gravity-magnetic separation-anionic reverse flotation. But the tailing grade maintained as high as24.02%. For this, the reason of high tailing grade was found by analysing samples systematically from the flowsheet of Donganshan Sintering Plant in this paper, and studied the effect of the size fraction of hematite and quartz and the mass ratio of hematite on the flotation performances that give a valid way to improve the indices, and has studied the de-adsorption mechanism of fine hematite particles from the surface of coarse quartz particles.The analysis of the samples from Donganshan Sintering Plant processing flowsheet includes chemical components, chemical phase, size distribution, liberation degrees of hematite and quartz through XRD, chemical multielement analysis, microscope identification, SEM and EDS. The results show that the main reason of high tailing grade is the adsorption of a lot of fine clean hematite particles to the surface of coarse quartz surface, which takes the hematite particles into the tailing by "carrier flotation".Tests involving the effect of size fraction of hematite and quartz and mass percents of hematite on flotation have been taken by orthogonal testing and measurement of adsorption. Results reveal that the main factor is the size of fraction of hematite and there is a proper correlation between the adsorption amount of fine hematite on the surface of quartz and the flotation performances, e.g. there is low recovery for the flotation of mixture of quartz and different percents-10μm hematite.De-adsorption-flotation results using different inorganic and organic desorbents and their mixtures show that proper addition of mixture of sodium silicate and CMC can effectively improve concentrate recovery and reduce tailing grade in the reverse flotation system using sodium oleate as collector. A desorption-flotation flowsheet of one roughing, one cleaning and three scavenging gives concentrate grade66.14%and recovery75.89%, and tailing grade 20.94%. In addition, the de-adsorption mechanism is analysed in this paper.This research can be used to guide the produce in Donganshan Sintering Plant for increasing the flotation recovery.