超高料层双层烧结富氧强化及烟气排放行为研究

Study of flue gas emission behavior and oxygen-enriched intensification of double-layer sintering with ultra-high bed

针对超高料层双层烧结矿强度低的问题,采用富氧方法强化双层烧结。研究富氧浓度和燃料用量对烧结矿产质量的影响,分析普通双层烧结和富氧强化双层烧结的烧结矿主要矿物组成和微观结构,研究两者烧结烟气中O_(2)、CO_(2)和CO的排放行为。研究结果表明:富氧方法能明显强化超高料层双层烧结,大幅度提高烧结矿成品率和转鼓强度;二次点火后对料层进行富氧,氧气体积分数为25%,烧结矿成品率、转鼓强度、利用系数和固体燃耗分别为69.06%、66.40%、2.09t/(m^(2)∙h)和53.79kg/t,与普通双层烧结指标相比,成品率、转鼓强度和利用系数分别提高4.11%、7.73%、0.18t/(m^(2)∙h),固体燃耗降低3.23kg/t;富氧使烧结矿中磁铁矿氧化充分,铁酸钙大量生成,烧结矿结构均质、紧密;富氧增大烧结烟气O_(2)质量分数,可有效解决下部料层缺氧问题,提高燃料燃烧效率,减少CO排放量。

In view of the problem of low strength of sintering product by double-layer sintering with ultra-high bed,oxygen-enriched method was used to intensify the double-layer sintering processes.The effects of oxygen-enriched concentration and fuel consumption on sintering indexes were studied,the mineral composition and microstructure of different sinters were analyzed,and the emission behaviors of O_(2),CO_(2) and CO in the sintering flue gas were identified.The results show that oxygen-enriched can significantly intensify the double-layer sintering processes with ultra-high bed and greatly improve the strength and yield of sinter.After the second ignition,the material layer is enriched with oxygen whose concentration is 25%,the yield,the tumbler strength,productivity and solid fuel consumption are 69.06%,66.40%,2.09 t/(m^(2)∙h)and 53.79 kg/t,respectively,compared with the common double-layer sintering,the yield,tumbler strength and productivity are increased by 4.11%,7.73%and 0.18 t/(m^(2)∙h),respectively,and the solid fuel consumption is reduced by 3.23 kg/t.The oxygen-enriched makes magnetite in sinter fully oxidized,and calcium ferrite especially needlelike calcium ferrite is massively generated,which makes the structure homogeneous and compact.Oxygen-enriched can increase the O_(2) content in sintering flue gas,solve the problem of oxygen-poor in the lower material layer,improve fuel combustion efficiency and reduce CO emission.