Experimental Study On Iron Increase And Phosphorus Reduction Of High Phosphorus Oolitic Hematite In Western Hubei

High phosphorus oolitic hematite is one of most complicated and refractory iron,which has a large reservation,occupied about 11% of the iron ores.The reservation of High phosphorus oolitic hematite which has been verified is about 3.72 billion ton in China.The new resource which could be verified is estimated to be more than 10 billion ton.Oolitics hematite is widely distributed and largely reserved in china, which is a complicated and internationally-known refractory iron.The mineralogy of oolitic hematite has been studied systemically by X-Ray Fluorescence(XRF), and polarizing microscope. It was learned that this oolitic hematite with 43.13% of Fe, the content of harmful element P is up to 0.86%,and the content of SiO2 is also high which is 17.20%. This ore is a typical kind of high phosphorus oolitic hematite, due to the complicated chemical composition and mineral oolitic structure, as well as disseminated grain size,many exploratory experiments were done for improving the grade of Fe and reducing the content of P.The raw ore was separated with the process of one rough separation to recovery iron, one fine separation,one scavenging separation after rough grinding. It was showed the conditions were best which the grinding fineness of-0.074 mm about 65%, roughing magnetic field intensity of 0.8T, cleaning magnetic field intensity of 0.5T, scavenging magnetic field intensity of 0.9T. The middlings were addressed again with magnetic separation again after gathering together for regrinding,which process is one rough separation, one fine separation, the best conditions of separation processing were the grinding fineness of-0.074 mm about 90%, roughing magnetic field intensity of 0.8T, cleaning magnetic field intensity of 0.4T. The concentrate with the Fe grade of 53.06%,which improved by 9.94% compared with the raw ore and Fe recovery of 78.53% and the magnetic tailing with the yeild of 36.18% and Fe grade of 25.59% were gained by adopting the closed-circuit process of re-magnetic separation of middles bact to regrinding. The index of concentrate was well and discarding tailing worked well.The study of reverse flotation experiment dealing with magnetic concentrate indicated that index of magnetic concentrate with the process of fine grinding-direct reverse flotation was not well,but the effect of reverse-flotation was improved after adding the desliming process. The best condition for selective flocculation desliming is:-0.038 mm occupied 95%,dispersing agent 12kg/t,NaOH 1.2kg/t,caustic starch 0.3kg/t. The best condition of reverse flotation roughing was: NaOH 2.0kg/t, starch 1.0kg/t,CaCl2 0.2kg/t,collector PL 0.8kg/t,the time of flotation was 4min.The tailing of reverse flotation with Fe grade of 56.75% which improved by 3.63% compared with magnetic concentrate and Fe recovery of 72.26% was obtained by adopting the closed-circuit process of fine grinding magnetic concentrate-selective flocculation desliming-reverse flotation, reverse flotation with the flowsheet of one roughing, two cleaning,one scavenging, the middling returned in turns.The study of acid lixiviated experiment dealing with the tailing of reverse flotation showed that under the condition of HCl dosage 100kg/t, LX dosage 5kg/t, reaction time 2h, lixiviated concentration 40%, stirring speed 200r/min.P content of the acid concentrate decreased to about 0.1%, with the Fe grade of 59.13% and recovery of 69.32%, it was learned that the phosphorus reduction effect.The optimum technological conditions in each phase were combined. The iron concentrate with the Fe grade of 59.20%,which improved by 16.07% compared with the raw ore,the Fe recovery of 69.96%, the P content in concentrate was only 0.1%, which dephosphorization rate was 94.07%,were obtained by adopt the combination flow of high gradient magnetic separation-selective flocculation desliming-anionic reverse flotation-acid lixiviate.The effect of dephosphorization and iron enrichment worked well. This processing flowsheet has great instructive significance on development of other oolitic hematite.The Zate results showed that: collector PL adsorbed on the surface of quartz which was activated by Ca2+ with chemical adsorption which resulted in the mineral surface hydrophobicity; the surface adsorption results showed that: after activating by Ca2+, the Adsorption of collector on quartz surface was the highest when the pH reached 11.