CO二次燃烧技术在AOD炉应用的研究与工业实践

Research and industrial practice of CO secondary combustion technology in AOD furnace

AOD炉冶炼不锈钢过程中由于加入大量的合金、渣料等导致热量存在较大的缺口,影响"脱碳保铬"的顺利进行。邢台钢铁有限责任公司采用"脱磷铁水→AOD炉→LF→CCM"工艺冶炼不锈钢,铁水碳含量较高可产生大量CO气体,同时脱碳期炉渣具有黏度和熔点高、呈颗粒状的特点,CO等气体能够快速从炉渣中释放出来,在吹炼过程中不会发生喷溅,为CO二次燃烧提供基础条件。有效利用CO二次燃烧释放热量可为吹炼过程提供一定的热量。通过工业实践表明:随着枪位的提高,CO二次燃烧比例逐步开始增加;在同工况下,对比两种类型的枪头,综合补偿热量和对炉龄的影响来看,三孔枪应用效果更好,CO二次燃烧比例达到20%,热量补偿约150℃,降低成本约40元/t,经济效益显著。

In the process of smelting stainless steel in AOD furnace,a large amount of alloy and slag lead to a large heat gap,which affects the smooth progress of"decarburization and chromium retention".Xingtai Iron and Steel Co.,Ltd.adopts"DEP→AOD→LF→CCM"smelting process of stainless steel,high carbon content of molten iron can produce a large amount of CO gas,at the same time phase decarburization slag with high viscosity and melting point,the granular characteristics.CO gas can be quickly released from slag,spillage will not occur in the process of converting,which provide basic conditions for CO secondary combustion.The effective utilization of heat released by CO secondary combustion can provide certain heat for the blowing process.The industrial practice shows that,with the increase of lance position,the proportion of CO secondary combustion begins to increase gradually.In this working condition,compared with two types of lance heads,the application effect of three hole gun is the best combining compensation of heat and the influence on furnace life.the proportion of CO secondary combustion reaches 20%,the heat compensation is about 150℃,the cost is reduced by about 40 yuan/t,the economic benefit is remarkable.