耐火材料 ›› 2021, Vol. 55 ›› Issue (5): 456-460.DOI: 10.3969/j.issn.1001-1935.2021.05.018

• 生产应用 • 上一篇    

MgCO3微粉加入量对氧化铝空心球浇注料结构和性能的影响

胡书禾1)(), 陈留刚2), 李飞3), 田学坤4), 张阳4), 叶国田2)   

  1. 1) 河南科技大学 高温材料研究院 河南洛阳 471003
    2) 郑州大学材料科学与工程学院 河南省高温功能材料重点实验室 河南郑州 450052
    3) 河南济源钢铁(集团)有限公司 河南济源 454150
    4) 中铝郑州有色金属研究院有限公司 河南郑州 450041
  • 收稿日期:2021-04-13 出版日期:2021-10-15 发布日期:2021-10-25
  • 作者简介:胡书禾:男,1971年生,博士,高级工程师。E-mail: hushuhe_hust@qq.com
  • 基金资助:
    国家自然科学基金项目(51972099);河南省科技厅科技攻关项目(192102210175)

Effect of MgCO3 micro-powder addition on structure and properties of alumina bubble castables

Hu Shuhe1)(), Chen Liugang2), Li Fei3), Tian Xuekun4), Zhang Yang4), Ye Guotian2)   

  1. 1) Institute of High Temperature Materials Research,Henan University of Science and Technology,Luoyang 471003,Henan,China
  • Received:2021-04-13 Online:2021-10-15 Published:2021-10-25

摘要:

为了开发出低密度、高强度、易成型、保温效果好的氧化铝空心球浇注料,将MgCO3微粉引入到氧化铝空心球浇注料基质中。采用粒度分别为5~3、3~1和1~0.2 mm的氧化铝空心球,板状刚玉细粉、氧化铝微粉和MgCO3微粉制备了氧化铝空心球浇注料试样,研究了MgCO3微粉加入量(w,0、1%、2%、3%、4%)对试样显微结构和性能的影响。结果表明:1)经1 500 ℃保温3 h热处理后,改变了基质中六铝酸钙(CA6)板片状的晶体形态,生成了粒度更加细小的镁铝尖晶石(MA)和CA6微晶共存的微晶结构,形成的MA-CA6微晶复合体均匀分布在基质空隙内部。2)110 ℃保温24 h处理后,浇注料体积密度从1.83 g·cm-3降低到1.58 g·cm-3,常温抗折强度大于5 MPa;1 500 ℃保温3 h处理后,加热永久线变化率保持在0~0.5%微膨胀,体积稳定性优异;400 ℃时的热导率下降近30%。

关键词: 氧化铝空心球浇注料, MgCO3微粉, CA6-MA微晶

Abstract:

To develop alumina bubble castables with low density,high strength,easy molding and good thermal insulation,MgCO3 micro-powder was introduced into their matrix.The alumina bubble castable samples were prepared using alumina bubbles with particle sizes of 5-3,3-1 and 1-0.2 mm,tabular corundum fine powder,alumina micro-powder and MgCO3 micro-powder.The effects of the MgCO3 micro-powder addition (0,1%,2%,3% and 4%,by mass) on the microstructure and the properties of the samples were studied.The results show that:(1)after firing at 1 500 ℃ for 3 h,the tabular crystal morphology of calcium hexaaluminate (CA6) in the matrix is changed,a microcrystalline structure of smaller granular magnesium aluminate spinel (MA) coexisting with CA6 microcrystalliteis formed,and the formed MA-CA6 micro crystallite complex is uniformly distributed in the matrix pores;(2)after firing at 110 ℃ for 24 h,the bulk density of the castables decreases from 1.83 g·cm-3 to 1.58 g·cm-3,and the cold modulus of ruptureis over 5 MPa;after firing at 1 500 ℃ for 3 h,the sample slightly expands(0-0.5% of the permanent linear change),showing excellent volume stability;and the thermal conductivity at 400 ℃ decreases by nearly 30%.

Key words: alumina bubble castables, magnesium carbonate micro-powder, calcium hexaaluminate-magnesium aluminate microcrystallite

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