回转窑内氧化球团物料对耐火材料侵蚀行为的研究
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摘要
氧化球团回转窑内结圈的形成对耐火材料造成蚀损,本文在实验室模拟现场条件,从铁元素渗透角度研究侵蚀料成分在不同条件下对耐材的侵蚀作用,研究结果表明:含高SiO_2和碱金属的侵蚀料会促进对耐火材料的侵蚀渗透,侵蚀料中SiO_2含量的增加会促进二次莫来石的形成,导致体积膨胀,从而加剧耐材侵蚀及结构破坏,碱金属会促使低熔点物质的形成,并在高温下形成导致体积膨胀的霞石类矿物,破坏耐火材料结构;随着连续高温保持时间的延长,侵蚀料对耐火材料的侵蚀程度加深。建议在采用回转窑工艺生产氧化球团过程中,应尽量采用低硅低碱金属的铁精矿,减少粘结剂膨润土的配加量;采用间歇降温操作,一方面利于减缓结圈物对耐火材料的侵蚀,一方面有助于结圈物的脱落。
Erosion of refractories occurs by ring formation in rotary kiln for oxidized pellets. In this paper,erosion effects of deposits to refractories under different compositions were studied on the view of iron penetration,by monitoring the site conditions in lab. The results show that: deposits with high contents of SiO_2 and alkalis are conductive to the iron penetration to refractory,where SiO_2 promotes the formation of secondary mullite,low melting temperature and nepheline materials are accelerated by alkalis,leading to the volume expansion and structural damage of refractory; deeper erosion happens by prolonging holding duration at continuous high temperature. Advices were proposed to using iron concentrates with low SiO_2 and alkalis,reducing the bentonite dosage during production of oxidized pellets by grate-kiln process,and taking intermittent cooling operation to slow down the erosion of ring to refractory and contribute to the fall off of ring.
Erosion of refractories occurs by ring formation in rotary kiln for oxidized pellets. In this paper,erosion effects of deposits to refractories under different compositions were studied on the view of iron penetration,by monitoring the site conditions in lab. The results show that: deposits with high contents of SiO_2 and alkalis are conductive to the iron penetration to refractory,where SiO_2 promotes the formation of secondary mullite,low melting temperature and nepheline materials are accelerated by alkalis,leading to the volume expansion and structural damage of refractory; deeper erosion happens by prolonging holding duration at continuous high temperature. Advices were proposed to using iron concentrates with low SiO_2 and alkalis,reducing the bentonite dosage during production of oxidized pellets by grate-kiln process,and taking intermittent cooling operation to slow down the erosion of ring to refractory and contribute to the fall off of ring.
引文
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[4]杨雪峰,姜涛,范晓慧,等.昆钢球团回转窑结圈机理研究及预防控制[J].烧结球团,2009,34(3):21-24.
[5]张子洋,梁永和,余为,等.球团矿回转窑耐火材料的蚀损及其对结圈的影响[J].硅酸盐通报,2009,(S1):110-113.
[6]聂建华,乔婉,张子洋,等.氧化铁与球团矿回转窑耐火材料的作用机理研究[J].稀有金属材料与工程,2011,(S1):174-177.
[7]Stjernberg J,Antti M,Nordin L,et al.Degradation of Refractory Bricks Used as Thermal Insulation in Rotary Kilns for Iron Ore Pellet Production[J].International Journal of Applied Ceramic Technology,2009,6(6):717-726.
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[9]Stjernberg J,Olivas-Ogaz M A,Antti M L,et al.Laboratory scale study of the degradation of mullite/corundum refractories by reaction with alkali-doped deposit materials[J].Ceramics International,2013,39(1):791-800.
[10]Stjernberg J,Lindblom B,Wikstrom J,et al.Microstructural characterization of alkali metal mediated high temperature reactions in mullite based refractories[J].Ceramics International,2010,36(2):733-740.
[11]NARITA K,ONOYE T,SATOH Y,et al.Effects of Alkalis and Zinc on the Wear of Blast Furnace Refractories and the Tuyere Displacement[J].Transactions of the Iron and Steel Institute of Japan,1981,21(12):839-845.
[12]德国钢铁工程师协会编.渣图集[M].北京:冶金工业出版社,1989:p69.
[2]范晓慧,甘敏,袁礼顺,等.氧化球团链篦机-回转窑结圈机理的研究[J].钢铁,2008,43(3):15-20.
[3]张汉泉.链篦机-回转窑氧化球团结圈结块原因及预防[J].金属矿山,2005,(07):59-61.
[4]杨雪峰,姜涛,范晓慧,等.昆钢球团回转窑结圈机理研究及预防控制[J].烧结球团,2009,34(3):21-24.
[5]张子洋,梁永和,余为,等.球团矿回转窑耐火材料的蚀损及其对结圈的影响[J].硅酸盐通报,2009,(S1):110-113.
[6]聂建华,乔婉,张子洋,等.氧化铁与球团矿回转窑耐火材料的作用机理研究[J].稀有金属材料与工程,2011,(S1):174-177.
[7]Stjernberg J,Antti M,Nordin L,et al.Degradation of Refractory Bricks Used as Thermal Insulation in Rotary Kilns for Iron Ore Pellet Production[J].International Journal of Applied Ceramic Technology,2009,6(6):717-726.
[8]Stjernberg J,Ion J C,Antti M,et al.Extended studies of degradation mechanisms in the refractory lining of a rotary kiln for iron ore pellet production[J].Journal of the European Ceramic Society,2012,32(8):1519-1528.
[9]Stjernberg J,Olivas-Ogaz M A,Antti M L,et al.Laboratory scale study of the degradation of mullite/corundum refractories by reaction with alkali-doped deposit materials[J].Ceramics International,2013,39(1):791-800.
[10]Stjernberg J,Lindblom B,Wikstrom J,et al.Microstructural characterization of alkali metal mediated high temperature reactions in mullite based refractories[J].Ceramics International,2010,36(2):733-740.
[11]NARITA K,ONOYE T,SATOH Y,et al.Effects of Alkalis and Zinc on the Wear of Blast Furnace Refractories and the Tuyere Displacement[J].Transactions of the Iron and Steel Institute of Japan,1981,21(12):839-845.
[12]德国钢铁工程师协会编.渣图集[M].北京:冶金工业出版社,1989:p69.