材料期刊网

为了探索复合铁酸钙的生成机制以优化烧结工艺,提高烧结矿质量,采用相平衡法研究了准化学平衡条件下Al2O3与MgO在烧结中的行为.结果表明,Al2O3和MgO的共同存在有利于复合铁酸钙(silico-ferrite of calcium and alminum,简称SFCA)的生成,但存在着交互作用,MgO促进赤铁矿分解生成磁铁矿,Al2O3的存在可抑制MgO的作用,减少磁铁矿生成,尤其在Al2O3质量分数较高时,MgO促进磁铁矿生成能力降低,促进SFCA生成作用增强.当MgO质量分数为2%时,添加质量分数2%的Al2O3矿相中磁铁矿质量分数快速降低,SFCA质量分数快速增加;随着Al2O3质量分数升高,SFCA晶面间距减小,晶体结构稳定性增强,有利于SFCA的生成;Al2O3质量分数超过3%后,孔洞结构增多,SFCA质量分数增加变缓,磁铁矿质量分数呈降低趋势,赤铁矿质量分数有升高趋势.

To clarify the formation mechanism of complex calcium ferrites for the optimization of sintering process and the improvement of sinter quality,the phase equilibrium method was adopted to research the behavior of Al2O3 and MgO in sintering process under the conditions of quasi chemical equilibrium.The results showed that MgO and Al2O3 were conducive to the generation of composite calcium ferrite(SFCA),but there was interaction between MgO and Al2O3.MgO facilitated the decomposition of hematite and the formation of magnetite,the facilitation of MgO was suppressed by Al2O3,especially at high Al2O3 mass fraction.The promotion effect of MgO on the generation of magnetite decreased and the effect on the generation of SFCA enhanced.When the MgO mass fraction was 2%,the magnetite mineral phase content rapidly decreased and the SFCA content increased rapidly after adding 2% Al2O3.With increasing the mass fraction of Al2O3,the SFCA interplanar crystal spacing decreased and the stability of crystal structure increased which was good for the generation of SFCA.When the Al2O3 mass fraction exceeded 3%,the pore structure increased,the SFCA mass fraction increased slowly and the magnetite mass fraction decreased, but the hematite mass fraction tended to increase.