熔铸锆铬刚玉耐火材料抗硼硅酸盐熔体的侵蚀行为

Corrosion Resistance of Fused-Cast AZCS Refractory by Borosilicate Melt

Al_(2)O_(3)–ZrO_(2)–Cr_(2)O_(3)–SiO_(2)(AZCS)材料是一种新型熔铸耐火材料,该材料在高温、高侵蚀性条件下的抗侵蚀性能优于其他类型的电熔耐火材料。为了研究该材料对硼硅酸盐玻璃熔体的抗侵蚀行为,利用含B_(2)O_(3)质量分数约12%的硼硅酸盐玻璃固化体对AZCS材料在1 500℃条件下进行侵蚀试验。结果表明:AZCS材料在侵蚀后,按照侵蚀程度可划分为变质层、过渡层、中心层。中心层变化很小,该层仍存在大量的铝–铬固溶体和斜锆石相,只有少量新形成的镁铝尖晶石相;渗入材料的MgO与固溶体反应,在原位形成镁铝尖晶石,并部分取代原有位置上的铝–铬固溶体。在过渡层中镁铝尖晶石形成的量达到最大,铝–铬固溶体溶解消失,该层存在的相为镁铝尖晶石相与斜锆石相;在变质层中基本只存在未被溶解的Cr_(2)O_(3)相,Cr_(2)O_(3)结构松散,呈蠕虫状形貌,铝–铬固溶体、斜锆石及镁铝尖晶石均溶解消失。

The Al_2O_3–ZrO_2–Cr_2O_3–SiO_(2) (AZCS) material as a new type of fused-cast refractory has better corrosion resistance than other fused refractories under high-temperature and high-corrosion resistance conditions.To investigate the erosion resistance behavior of the material to the borosilicate glass melt,the AZCS material was subjected to an erosion test at 1 500℃,by using borosilicate glass waste-forms containing B_2O_(3) of 12%(in mass fraction).The samples before and after erosion were analyzed by chemical analysis,X-ray diffraction,scanning electron microscopy and energy disperse spectroscopy.The results show that AZCS material can be divided into the metamorphic layer,transitional layer and central layer based on the degree of corrosion.The central layer changes little,there are still a large amount of aluminum-chromium solid solution and baddeleyite,and only a small amount of newly formed magnesia-alumina spinel.MgO infiltrating the material reacts with the solid solution to form the MA spinel in situ and partially replaces the aluminum-chromium solid solution in the original position.In the transitional layer,the maximum amount of MA spinel is formed,and the Al-Cr solid solution dissolves and disappears.Therefore,the phases in this layer are MA spinel and baddeleyite.In the metamorphic layer,there is basically only undissolved Cr_2O_(3) phase with a loose Cr_2O_(3) structure and a worm-like morphology.Aluminum-chromium solid solution,baddeleyite and MA spinel dissolve and disappear.