环境气氛对煤灰在Al_2O_3-Cr_2O_3-ZrO_2材料上结渣的影响

Effect of coal ash slagging on Al_2O_3-Cr_2O_3-ZrO_2 refractories in different atmospheres

以白刚玉、α-Al2O3粉、锆英石和氧化铬为主要原料,在200 MPa油压机上压制成50 mm×50 mm×5 mm的试样,在空气气氛中于1 500℃煅烧5 h,制得Al2O3-Cr2O3-ZrO2试样。将0.6 g变形温度约为1 120℃的云贵煤灰平铺在Al2O3-Cr2O3-ZrO2试样上,然后放入马弗炉中分别在空气和弱还原性气氛下于1 250℃煅烧5 h,随炉冷却后观察煤灰在Al2O3-Cr2O3-ZrO2试样上的结渣情况,并进行SEM及EDS分析。结果表明:在弱还原气氛条件下,煤灰在Al2O3-Cr2O3-ZrO2上的结渣非常致密;而在空气气氛条件下,煤灰与Al2O3-Cr2O3-ZrO2材料间的粘接比较疏松,两者间没有明显的相互渗透。

With the starting materials of white corundum,α-Al2O3 powder, zircon and chrome oxide,Al2O3 -Cr2O3 -ZrO2 specimens with dimensions of 50 mm ×50 mm ×5 mm were pressed under 200 MPa in an oil press and fired at 1500 ℃ for 5 h. Yungui coal ash （0.6 g, deformation temperature≈120 ℃） was spread on the Al2O3 -Cr2O3 -ZrO2 specimens and fired at 1 250 ℃ for 5 h in air and weak reducing atmosphere, respectively. The slag-bonding state of the specimen was observed and analyzed by SEM and EDS after naturally cooling. The results showed that the slag-bonding state fired in weak reducing atmosphere was very tight but loose in air without obvious penetration.