碱度对含钡磁铁矿粉球团固结机理影响

    Effect of Basicity on Pelletizing Mechanism of Barium Bearing Magnetite

    • 摘要: 本文以含钡磁铁精矿粉和膨润土为原料,通过配加一定比例的Ca(OH)2,研究碱度对含钡球团矿抗压强度的影响,并采用X射线衍射仪、扫描电子显微镜-能谱仪等手段,结合同步热分析仪,分析含钡球团矿的固结机理。结果表明,随着碱度的增加,含钡球团矿的抗压强度先增加后减少,在碱度为0.8时达到最大值,为3 292.8 N/个,而球团的孔隙率呈相反变化趋势,最小孔隙率为21.6%;Ca(OH)2分解出的CaO进而分别与Fe2O3和SiO2反应生成CaFe2O4和CaSiO3,且少量的Ca2FeO4填充在孔隙中,降低球团的孔隙率增加抗压强度。BaSO4分解为BaO和SO2,其中BaO与Fe2O3反应生成BaFe2O4,SO2气体从球团矿内部逸出,降低球团矿基体的致密性,导致球团矿微观结构疏松多孔。

       

      Abstract: In this article, the effect of basicity on the compressive strength of barium bearing pellets was studied by adding a certain proportion of Ca(OH)2 with barium bearing magnetite concentrate powder and bentonite as raw materials. The consolidation mechanism of barium bearing pellets was analyzed by means of X-ray diffrotometer, scanning electron microscope-energy spectrometer and synchronous thermal analyzer. The results show that with the increase of basicity, the compressive strength of barium-bearing pellets increases first and then decreases, and reaches the maximum value of 3 292.8 N/ pellet when the basicity is 0.8, while the porosity of pellets shows an opposite trend and the minimum porosity is 21.6%. CaO decomposed by Ca(OH)2 reacts with Fe2O3 and SiO2 respectively to form CaFe2O4 and CaSiO3, and a small amount of Ca2FeO4 fills the pores to reduce the porosity of the pellets and increase the compressive strength. BaSO4 is decomposed into BaO and SO2, and BaO reacts with Fe2O3 to form BaFe2O4. SO2 gas escapes from inside the pellet, reducing the compactness of the pellet matrix, resulting in loose and porous microstructure of the pellet.

       

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