Study On Palletizing,Oxidizing And Roasting Performance Of Ji Dong Iron Concentrate

Considering the characteristics of the Jidong magnetite concentrates. It is researched and analyzed that the influence of moisture, contents of bentonite and granularity composition of fine ore powders on the balling capability; the oxidized and roasted mechanism of Jidong magnetite pellets and the main factors related to the roasting quality. Brought forward the measures to improve the balling and roasting of Jidong magnetite fine.By mineralogical analysis of Jidong magnetite concentrates what can be found is that: It is mainly composed of magnetite, concentrate grain is medium-coarse granular crystal texture, the most is subidiomorphic or xenomorphic, is chevron and granulated, surface of the concentrate is smooth, minority of concentrate has inclusion or intergrowth, grain inch normally is 0.05~0.16mm, there is incompletely cleavage in concentrate grain. Gangue minerals mostly is quartz, the ratio of quartz is 4%~6%, also there are few pyrite,carbonate and silicate ect.By balling experiment what can be found is that: because glazed surface of Jidong fine magnetite concentrate, moreover water intake capacity and adhesion of glassiness crystal surface is worse than that of coarse surface, so friction between grains is small; as well as owing to high gangue content, and that gangue has big impact on hydrophile of iron ore, low wettability of quartz, so hydrophile of Jidong fine magnetite concentrate is reduced, result in balling capacity is bad. Therefore at production, bentonite proportion in Jidong magnetite concentrates more that in other high quality concentrate. With bentonite ratio increasing, not only can improves green ball drop number and compression strength, but also can increases green ball shock temperature; moisture has markedly effect on green ball properties, optimal balling moisture should be 7.9%~8.4%; With reduction of concentrate inch, green ball strength increases, but shock temperature decreases markedly.By roasting oxidation experiment what can be found is that: The oxidation process of Jidong magnetite concentrate pellets obeys"unreacted core model"macroscopically, but in microscopic, there is incompletely cleavage in Jidong magnetite concentrate grain, and octahedron crack exists in magnetite crystal, oxidation develops along octahedron crack or cleavage seam, forms strip oxidation texture or diamond lattice oxidation texture. Oxidized temperature has directly effect on balling oxidation, the oxidizing temperature is reasonable between 900℃to 950℃. Gangue composition has no impact on pellets'oxidation process, but has markedly impact on roasting. The optimal roasting temperature of Jidong magnetite concentrate pellets is between 1250℃to 1275℃.