| Baotou Iron and Steel(Group)Co.Is located in the Inland area.Freight of Australian and other foreign ores is 170 yuan/t higher than that of coastal iron and steel enterprises.If other lump ores can be used instead of Australian ore,great economic benefits will be achieved.In this paper,the Mongolian lump ore basic metallurgical properties of ore phase,burst index,reducibility and metal droplet were studied.The possibility of substituting Mongolian lump ores for Australian lump ores is explored.The chemical composition of Mongolia and Austrlian lump ores were measured by titration method.The ore phase and burst index of the two lump ores were tested and analyzed.The thermal decomposition properties of Monogolian and Australian ores were tested by comprehensive thermal analysis.At the same time,the reducibility of sinter,pellet and two kinds of lump ores were measured.The shrinkage and metal droplet were tested.The iron grade of Mongolia ore is low,the content of harmful impurities is higher.Mongolian lump ore has poor reducibility and high thermal burst index.Australian ore has higher iron grade,lower impurity content and better reducibility.The content of Na and K in Mongolian ore is higher than that in Australian ore.Magnetite and limonite are the main iorn mineral in Mongolian lump ores,and a small amount of hematite can be detected.There are about 70% magnetite(volume ratio,the same below),15% limonite,and15% gangue in Mongolian ore.The grain size of Mongolian ore is larger.There are some fluorine and alkali in gangue.There are high burst index for Mongolia ore.It will not bust to produce fines or powders less than 6.3mm.The burst index of Australia ore is below 2.45%.The quality loss of Mongolian ore in heating process is smaller than that of Australian ore.The reducibility experiment shows that sinter has good reducibility,reaching 81.14%,followed by Australian ore,with reducibility of 74.15%,and pellet with reducibility of72.05%.Mongolian ore block has the worst reducibility,its reducibility is 67.16%,and the reducibility index of Mongolian ore is only 0.37.the shrinkage test of comprehensive burden shows that the volume shrinkage of burden is the smallest(29.5%)when Mongolian ore is not added.When Mongolian ore is added,the volume shrinkage increases.When Mongolianore is added at 5%,the volume shrinkage is the highest(34.7%)and increases 5.2% than that of free-Mongolian ore.Adding 10% Mongolian ore and 10% Australian ore,the volume shrinkage rate is 31.6%,which is only 2.1% higher than that of non-Mongolian ore.It has little effect on the shrinkage of burden and the permeability of blast furnace.When the consumption of sinter and pellet are fixed,the softening temperature is the highest when Mongolian ore is not added.When Mongolian ore was added 5%,the final softening temperature decreased about 50 ?,the range of softening temperature becomes wider,and the pressure difference reaches 9.2KPa.When Mongolian ore was added 10%,there were increases for the softening temperature and the final softening temperature,and the pressure difference is the same as that of free Mongolian ore.The production test showed that there were little effect on BF smelting operation for Btsteel BF and the indices of the blast furnace had little change. |
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