CaO-Al_(2)O_(3)-Ce_(2)O_(3)渣系的相平衡关系研究

Phase Coexistence Relationship of CaO-Al_(2)O_(3)-Ce_(2)O_(3)Slag System

CaO-Al_(2)O_(3)-Ce_(2)O_(3)渣系是稀土钢新型冶金渣系的基础渣系,其相平衡关系等热力学信息的缺失限制了相关渣系的研究和开发。本文通过高温相平衡实验,结合X射线衍射分析、扫描电镜及能谱分析,研究了CaO-Al_(2)O_(3)-Ce_(2)O_(3)渣系的相平衡关系。根据1100℃的实验结果,明确了该渣系中十种物相间的共存关系,以Alkemade连线的形式展示,包括:2CaO·Al_(2)O_(3)·Ce_(2)O_(3)-CaO、2CaO·Al_(2)O_(3)·Ce_(2)O_(3)-Ce_(2)O_(3)、2CaO·Al_(2)O_(3)·Ce_(2)O_(3)-3CaO·Al_(2)O_(3)、2CaO·Al_(2)O_(3)·Ce_(2)O_(3)-Ce_(2)O_(3)·Al_(2)O_(3)、2CaO·Al_(2)O_(3)·Ce_(2)O_(3)-2CaO·Al_(2)O_(3)·Ce_(2)O_(3)、2CaO·3Al_(2)O_(3)·Ce_(2)O_(3)-Ce_(2)O_(3)·Al_(2)O_(3)、2CaO·3Al_(2)O_(3)·Ce_(2)O_(3)-3CaO·Al_(2)O_(3)、2CaO·3Al_(2)O_(3)·Ce_(2)O_(3)-CaO·Al_(2)O_(3)、2CaO·3Al_(2)O_(3)·Ce_(2)O_(3)-CaO·2Al_(2)O_(3)、Ce_(2)O_(3)·Al_(2)O_(3)-CaO·2Al_(2)O_(3)、Ce_(2)O_(3)·Al_(2)O_(3)-CaO·6Al_(2)O_(3)。根据1600℃的实验结果,绘制了1600℃的等温截面图,确定了其中的4个三相区、5个两相区、单一液相区,包括:液相+CaO+2CaO·Al_(2)O_(3)·Ce_(2)O_(3)、液相+Al_(2)O_(3)·Ce_(2)O_(3)+2CaO·Al_(2)O_(3)·Ce_(2)O_(3)、液相+Al_(2)O_(3)·Ce_(2)O_(3)+2CaO·3Al_(2)O_(3)·Ce_(2)O_(3)、液相+2CaO·3Al_(2)O_(3)·Ce_(2)O_(3)+CaO·2Al_(2)O_(3)、液相+CaO、液相+2CaO·Al_(2)O_(3)·Ce_(2)O_(3)、液相+Al_(2)O_(3)·Ce_(2)O_(3)、液相+2CaO·3Al_(2)O_(3)·Ce_(2)O_(3)、Liquid+CaO·2Al_(2)O_(3)、液相区。

CaO-Al_(2)O_(3)-Ce_(2)O_(3),slag system is a new basie metallurgical slag system for rare earth steel.The lack of thermo-dynamie information,such as the phase equilibrium relationship,limits the research and development of related slag systems.In this paper,the phase equilibrurmn relationship of CaO-Al_(2)O_(3)-Ce_(2)O_(3),slag system was studied through high temperature phase equilibrium experiment;X-ray diffraction analysis,scanning electron mieroscope and energy spectrum analysis were used to determine the composition of equilibrium phase.According to the experimental results at 1100 C,the coexistence relationship of the slag system was determined and displayed in the form of alkemade lines as fllos:2CaO·Al_(2)O_(3)·Ce_(2)O_(3)-CaO、2CaO·Al_(2)O_(3)·Ce_(2)O_(3)-Ce_(2)O_(3)、2CaO·Al_(2)O_(3)·Ce_(2)O_(3)-3CaO·Al_(2)O_(3)、2CaO·Al_(2)O_(3)·Ce_(2)O_(3)-Ce_(2)O_(3)·Al_(2)O_(3)、2CaO·Al_(2)O_(3)·Ce_(2)O_(3)-2CaO·Al_(2)O_(3)·Ce_(2)O_(3)、2CaO·3Al_(2)O_(3)·Ce_(2)O_(3)-Ce_(2)O_(3)·Al_(2)O_(3)、2CaO·3Al_(2)O_(3)·Ce_(2)O_(3)-3CaO·Al_(2)O_(3)、2CaO·3Al_(2)O_(3)·Ce_(2)O_(3)-CaO·Al_(2)O_(3)、2CaO·3Al_(2)O_(3)·Ce_(2)O_(3)-CaO·2Al_(2)O_(3)、Ce_(2)O_(3)·Al_(2)O_(3)-CaO·2Al_(2)O_(3)、Ce_(2)O_(3)·Al_(2)O_(3)-CaO·6Al_(2)O_(3),According to the experimental resuls at 1600 C,the isothermal section at 1600 C was obuained;four three-phase fields,five two-phase fields and single liquid phase fields were determined,as fllows:liquid+CaO+2CaO·Al_(2)O_(3)·Ce_(2)O_(3),liquidAl_(2)O_(3)·Ce_(2)O_(3)+2CaO·Al_(2)O_(3)·Ce_(2)O_(3),liquid+Al_(2)O_(3)·Ce_(2)O_(3)+2CaO·3Al_(2)O_(3)·Ce_(2)O_(3),lquid+2CaO·3Al_(2)O_(3)·Ce_(2)O_(3)+CaO·2Al_(2)O_(3),liquid+CaO,liquid++2CaO·Al_(2)O_(3)·Ce_(2)O_(3)liquid+Al_(2)O_(3)·Ce_(2)O_(3)liquid+2CaO·3Al_(2)O_(3)·Ce_(2)O_(3)、Liquid+CaO·2Al_(2)O_(3)and single liquid phase field.