Effect of w(MgO)/w(Al_2O_3) ratio and basicity on microstructure and metallurgical properties of blast furnace slag
Effect of w(MgO)/w(Al_2O_3) ratio and basicity on microstructure and metallurgical properties of blast furnace slag
复制标题
w(MgO)/w(Al_2O_3)比和碱度对高炉渣显微组织和冶金性能的影响
DOI：
10.1007/s42243-021-00622-1
复制
发表时间：
2021
期刊：
影响因子：
--
通讯作者：
He Zhijun
中科院分区：
文献类型：
--
作者：
Kong Weiguo;Liu Jihui;Yu Yaowei;Hou Xinmei;He Zhijun
The CaO-SiO_2-Al_2O_3-MgO system is the main component unit in the slag formation process in blast furnace smelting.Its structural changes directly affect the high-temperature metallurgical properties of slag.Molecular dynamics simulations were thus conducted to analyze the microstructure changes of the quaternary slag system under different basicities and w(MgO)/w(Al_2O_3) ratios.The changes in w(MgO)/w(Al_2O_3) ratio and basicity could affect the stability of each ionoxygen.Increasing the basicity and w(MgO)/w(Al_2O_3) ratio, the average coordination number of O surrounding Si atom only changed a little and remained approximately 4,indicating that Si exists as a stable structure of the [SiO_4]~(4-)tetrahedron in the slag structure, while the average coordination number of O surrounding Al atom changed greatly from 4 to 6,which indicated that the Al existence form could be transformed from [AlO_4]~(5-)tetrahedron to [AlO_5]~(7-)pentahedron and [AlO_6]~(9-)octahedron.Also, the diffusion rate of ions was accelerated with the increase in w(MgO)/w(Al_2O_3) ratio and basicity.Moreover, the self-diffusion coefficients of each ion were obtained, and the magnitudes were observed to be in the following order: Mg~(2+) >Ca~(2+) >Al~(3+) >Si~(4+).The calculation and analysis of the slag viscosity and activation energy of viscous flow under different basicities and w(MgO)/w(Al_2O_3) ratios revealed that the metallurgical properties of slag at high temperature depend on the flow-unit diffusivity and the microstructure stability, simultaneously, the basicity should be controlled between 1.0 and 1.2, and the w(MgO)/w(Al_2O_3) ratio could be controlled between 0.45 and 0.55.
