Study On Flotation Technique And Thickening And Dewatering Of High Grade Pyrite Concentrate

Pyrite concentrate is one of 100 categories of important chemical products, which is mainly used to produce sulfuric acid, and partly used in agrochemical, medicine, explosive, metallurgy and oil industries. In this paper, based on mineralogy, the flotation technology and reagent system for producing high grade pyrite concentrate by using the pyrite concentrates with the grades of about 46% S and 48% S from Da Plant and Huaguang Company respectively in Jinduicheng Molybdenum industry Co. Ltd., were investigated, and the dewatering properties of high grade pyrite concentrate obtained was also studied.XRD and SEM analysis showed that the mineral constituents in pyrite concentrates from Da Plant and Huaguang Company were basically same, the main mineral was pyrite, while secondary minerals were chalcopyrite, molybdenite, hametite, sphalerite and galena etc.. The size analysis showed that the grades of sulfur and iron in +325 mesh of the pyrite concentrates from Da Plant and Huaguang Company were higher, but didn't reach up to the requirements of high grade pyrite concentrate. Mineralogy indicated that the intergrowth pyrites in every sieve internals were little, but the intergrowth relationship is complicated. The purity of high grade pyrite concentrate should be more than 96%, so the existence of intergrowth minerals with pyrite could affect the production of high grade pyrite concentrate.Based on the above investigation, through optimizing the flotation technology and reagent system, the batch laboratory tests showed that when the content of —325 mesh accounted for 95% after re-grinding the pyrite concentrate from Da Plant, the qualified high grade pyrite concentrate with the yield of 54.21%, the grades of 50.62% S and recovery of 60.27% , 45.81% Fe and recovery of 60.27%, could be obtained by usingthe flotation flowsheet with one roughing stage, three cleaning stages and middlings backing out in turn.The mineralogy of pyrite concentrate from Huaguang Company was also studied. Based on the mineralogy results, the flotation technology and reagent system were investigated for producing high grade pyrite concentrate by using the pyrite concentrate from Huaguang Company as raw material. The obtained results indicated that the contents of galena, chalcopyrite, sphalerite and molybdenite were relatively higher, even if the content of —325 mesh accounted for 95% after re-grinding the pyrite concentrate from Huaguang Company, the final high grade pyrite concentrate with the grade of more than 45% could not obtained through the open flotation flowsheet with one roughing stage and two cleaning stages. The qualified high grade pyrite concentrate can not be produced by using the pyrite concentrate as raw material.The dewatering test of the high grade pyrite concentrate obtained was carried out. The results showed that although the size was very small( more than 90% -325 mesh), and there was some reagent in high grade pyrite concentrate, its sedimentation velocity was fast, and the sedimentation was very easy. Therefore, the ordinary thickener or thickening pool can be used. The researches of drying properties of high grade pyrite concentrate showed that the size was very small, but its purity was very high, and there was basically no clay minerals, so the drying velocity was fast, and the high grade pyrite concentrate with moist content of less than 0.2% was easy to obtained.The achievement of producing technology of high grade pyrite concentrate expands the use of pyrite concentrate product, improves the market competing ability of products in Jinduicheng Molybdenum industry Co. Ltd.. the high grade pyrite concentrate has amplitude developing prospect.