SiC加入量及烧成气氛对MgO-MgAl_2O_4质耐火材料性能的影响  

Effects of SiC addition and firing atmosphere on properties of MgO-MgAl_2O_4 refractories

作　　者：丁雄风 赵惠忠[1] 张寒[1] 余俊[1] 赵鹏达 

机构地区：[1]武汉科技大学省部共建耐火材料与冶金国家重点实验室,湖北武汉430081

出　　处：《耐火材料》2017年第3期191-195,共5页Refractories

摘　　要：为改善炭素焙烧炉火道墙的导热性能,以高纯镁砂(5~2、≤2和≤0.088 mm)和预合成镁铝尖晶石(≤1 mm)为原料,SiC粉(≤0.088 mm)为添加剂,热固性酚醛树脂为结合剂,经配料、成型、烘干、1 500℃热处理3 h后,制备了MgO-MgAl_2O_4质耐火材料试样,并分别研究了SiC粉的加入量(质量分数分别为0、1%、2%、3%和4%)和烧成气氛(空气气氛或埋炭气氛)对MgO-MgAl_2O_4质耐火材料性能和显微结构的影响。结果表明:当SiC加入量为3%(w)时,经空气气氛烧后试样综合性能最好;当SiC加入量为4%(w)时,经空气气氛烧后试样的中心部位SiC氧化成SiO气体,形成边缘致密而中心疏松的蓄热体结构,热导率急剧下降;加入SiC后经埋炭烧后试样,由于SiC被氧化成SiO气体,导致试样孔隙率增加,试样的强度及热导率有所下降。In order to improve the thermal conductivity of the flue wall of carbon baking furnaces,high purity magnesia （5-2 mm,≤2 mm, 〈0.088 mm） and pre-synthesized magnesium aluminate spinel （≤1 mm） were used as starting materials,SiC （ 〈0.088 mm） as an additive,and thermosetting phenolic resin as a binder to prepare Mg0-MgAI204 refractories.The starting materials were batched,shaped,dried,and fired at 1 500 ℃ for 3 h to obtain the final specimens. The effects of SiC addition （0,1% ,2% ,3% ,and 4% ,by mass） and firing atmosphere （in air or carbon embedded atmosphere） on the properties and microstruc-ture of Mg0-MgAI204 refractories were investigated. The results show that the specimen fired in air with 3% SiC shows the optimum comprehensive properties;for the specimen with 4% SiC fired in air,SiC in its central part is oxidized into SiO gas,forming a regenerator structure dense in the edges but loose inside, which results in a sharp decrease of the thermal conductivity;for the specimens fired with carbon embed-ded, SiC is oxidized into SiO gas, which increases the porosity and declines the strength and thermal conductivity.

关 键 词：SIC MgO-MgAl2O4 烧成气氛 热导率 炭素焙烧炉 

分 类 号：TQ175.7[化学工程—硅酸盐工业]