CaCO3微粉对刚玉质弥散型透气砖性能的影响

弥散型透气砖因具有供气可靠性好、安全性高和精炼效果好等优点得到较多应用,然而其自身多孔结构导致的强度低和使用寿命短等缺陷限制了它的应用。为优化刚玉质弥散型透气砖的使用性能,本文以电熔白刚玉颗粒及细粉、α-Al₂O₃微粉、Cr₂O₃微粉等为主要原料,固定颗粒与细粉的质量比为85∶15,分别用质量分数为0%、1%、2%、3%的CaCO₃等量替代电熔白刚玉细粉,探索CaCO₃微粉的引入对弥散砖性能的影响。结果表明:随CaCO₃微粉加入量增加(0%~2%),弥散砖材料常温强度和高温强度增加,由于CaCO₃分解生成的CaO与基质中的Al₂O₃反应生成六铝酸钙,其相互穿插连接增加了基质间的结合程度,从而提高了材料的强度。

Effect of CaCO3 Micropowder on Properties of Corundum Based Porous Purging Plug

Porous purging plugs have been widely used due to the advantages of good air supply reliability, high safety and good refining effect. However, its application is limited by the defect such as low strength and short service life caused by its own porous structure. In order to further improve the properties of corundum based porous purging plugs, fused white corundum particles and fine powder, α-Al₂O₃ micropowder and Cr₂O₃ micropowder were used as raw materials, the mass ratio of aggregate to matrix was fixed at 85∶15, and 0%, 1%, 2% and 3% (mass fraction) CaCO₃ were used to replace fused white corundum fine powder, respectively. The effect of the introduction of CaCO₃ micropowder on the properties of porous purging plugs was explored. The results show that the strength at room temperature and high temperature all increase with the amount of CaCO₃ powder (from 0% to 2%). The main reason is that the CaO formed by the decomposition of CaCO₃ reacts with Al₂O₃ in the matrix to form calcium hexaaluminate, which intersperses and connects with each other to increase the bonding degree between the matrix, thus improving the strength of the samples.