Effect of content of Al₂O₃ and MgO on crystallization of blast furnace slag during fiber formation

Abstract

The simulation of blast furnace slag was prepared by pure chemical reagents. Test methods like DSC, XRD and SEM were used to study the effect of Al₂O₃ and MgO content on crystallization of blast furnace slag during fiber formation. The results show that as Al₂O₃ and MgO contents in the sample changed, blast furnace slag was crystallized at the average temperature below 1232 K. When the ratio of Mg/Al in the samples is 0.6 calculated by Kissinger equation, crystallization activation energy is at the maximum value and the system is in the most stable condition. The sample crystallization phases are mainly calcium akermanite (2CaO·MgO·2SiO₂) and gehlenite (2CaO·Al₂O₃·SiO₂). Secondary crystallization phases are anorthite (CaAl₂Si₂O₈), wollastonite minerals (WOLLA) and pyroxene minerals (cPyrA). Meanwhile, the principal crystallization phases of the samples are different types and have different contents, and the microstructures of the sample sections are different due to the difference between MgO/Al₂O₃ ratio.

摘要

模拟高炉渣成分采用化学纯试剂配制了实验原料, 采用 DSC、 XRD 和 SEM 等测试手段研究了 Al₂O₃, MgO 含量对高炉渣成纤过程析晶行为的影响。 结果表明: 随着试样中 Al₂O₃ 和 MgO 含量的变化均呈现了析晶现象, 析晶温度均在 1232 K 以下。 通过 Kissinger 方程计算, 当试样中镁铝比为 0.6 时, 析晶活化能最大, 此时体系最稳定。 试样析出的晶相主要有钙镁黄长石 (2CaO·MgO·2SiO₂) 和钙铝黄长石 (2CaO·Al₂O₃·SiO₂), 次要晶相有钙长石 (CaAl₂Si₂O₈)、 硅灰石类矿物 (WOLLA) 和辉石类矿物 (cPyrA)。 同时, 由于 Al₂O₃, MgO 含量不同, 试样析出的主晶相的种类及含量不同, 试样断面微观形貌不同。