三水铝石型高铝褐铁矿粉烧结液相生成特性

Melt Formation Phenomena of High Alumina Limonite of Gibbsite Type in Sintering Process

烧结矿依靠液相黏结未熔颗粒获得强度，因此铁矿粉与CaO反应生成液相的能力对保证烧结矿质量非常重要。采用高温综合热分析仪（TG-DSC）对塞拉利昂高铝铁矿粉配加CaO的液相生成特性进行了研究。试验结果表明：提高CaO的配比，可以增加液相生成量，液相生成峰值温度基本稳定在1209℃左右；随着矿粉粒度逐渐减小，液相生成量一直减少，同时，液相生成峰值温度先降低后增加，当粒度为0.074～0.180 mm时，液相生成温度最低；熔剂粒度的增加可增加液相生成量，同时初始液相生成温度显著提高；与生石灰（CaO）相比，采用石灰石（CaCO3）做钙源可以降低液相生成温度、增加液相量；与其他种类的矿粉对比表明，高铝铁矿粉其液相生成温度最高，反应性最差， Al2O3含量一般的澳大利亚褐铁矿的液相生成温度相对较低，高品位磁铁矿的液相生成温度最低，反应性良好。烧结杯试验表明，随着塞拉利昂铁矿配比的增加，成品率从78.37%逐渐降低到73.36%，烧结矿的转鼓强度由60.5%逐渐下降到49.6%，该高铝矿的配加比例应控制在混匀矿的20%以内。

Sinter is consolidated by melt phase through adhering the adjacent unreacted nucleus and therefore the melt for-mation ability of iron ore fine with CaO is very important to guarantee the quality of the sinter. The high temperature si-multaneous thermal analyzer was used to examine the melt formation phenomena of Sierra Leone high alumina iron ore fine with CaO. The melt amount increased with the increasing of CaO content and the melt formation peak temperature of the iron ore was stably kept at around 1 209 ℃. The amount of melt decreased and the melt formation temperature de-creased first and then increased with the particle size decreasing. The Sierra Leone high alumina iron ore fine with diame-ter from 0.074 mm to 0.180 mm had the lowest melt formation temperature. The formation temperature and amount of the melt could be both significantly increased with the increasing of flux particle size. When using limestone as the calcium re-source, the melt formation temperature was lower and the amount of melt was more than using the calcined lime. Com-pared with the other kinds of iron ores, the sierra leone high alumina iron ore had the highest melt formation temperature. The medium alumina content limonite had the relatively lower melt formation temperature. The magnetite iron ore fine had the best melt formation property. The sintering pot test result showed that the yield of sinter decreased from 78.37%to 73.36%and the tumbling index decreased from 60.5%to 49.6%with the increasing of Sierra Leone iron ore addition. The appropriate addition ratio should be less than 20%of the ore blender.