衡钢高炉炉缸炭砖侵蚀过快的原因浅析

Analysis on the Causes of Rapid Carbon Brick Erosion in Hengyang Steel No.1 BF Hearth

衡钢1号高炉大修投产后不到2年,炉缸个别点温度最高上升到900℃左右,危及安全生产,被迫停炉中修。停炉后观察发现,炉缸炉底呈“象脚状”侵蚀,炉缸第1层炭砖侵蚀严重,最薄弱处炭砖残余厚度仅240mm,从残铁口扒渣门两边炉缸第7~9层炭砖中部可见明显的环裂缝。认为1号高炉炉缸炭砖侵蚀过快的原因主要是:(1)高冶炼强度操作,且炉缸直径偏小,致使炉缸铁水环流强;(2)炉缸炉底耐材部分指标不达标;(3)炭砖冷面与冷却壁之间的炭素捣打料层存在气隙;(4)Pb、Zn及碱金属等有害元素控制不力;(5)铁口深度合格率低。

Hengyang Steel No.1 BF suffers rapid erosion of its first layer of the hearth wall carbon bricks near the tuyere after resuming production for less than two years after revamping,and the highest temperature of the hearth side wall rises to about 900℃,which seriously endanger the safety of production,therefore,oxygen enrichment operation has to be stopped to control the smelting intensity.It is found,during medium maintenance,that the first layer of the hearth wall carbon bricks on both sides of the taphole and below No.12 tuyere are seriously eroded,and it is just 240mm thick at the thinnest portion;serious ring cracks appear in the hearth wall carbon bricks of the layer No.7-9,and"elephantfoot-like"erosion develops somewhere at the furnace bottom.It is believed the rapid erosion of the hearth wall carbon brick is mainly caused by higher smelting intensity for a long time,smaller hearth diameter,unqualified performance indicators of refractory materials at the furnace bottom and hearth,air gap between the cold surface of the carbon bricks and carbon ramming materials of the cooling stave,and improper depth of the taphole.Facing this situation,suggestions are put forward for the follow-up production.