料面喷吹蒸汽对烧结矿产质量和CO排放的影响

 随着钢铁行业烧结烟气污染物超低排放标准的持续收紧,烧结料面喷吹技术以其节能减排提质的潜在优势成为新的研究热点,被广泛认为是当前具有一定综合减排效果的烧结过程控制技术。为探究料面喷吹蒸汽的最优工艺制度,查明蒸汽喷吹影响烧结过程的作用机理,以期实现其工业化应用,采用某钢铁厂的烧结原料,研究了蒸汽喷吹总量、喷吹流量及开始喷吹时刻对烧结矿产质量指标及CO排放的影响。结果表明,在50 kg 级烧结杯原料条件下,料面喷吹蒸汽最佳试验条件应为烧结点火8 min后连续喷15 min,喷吹流量为0.02 m3/min,喷吹总量为180 g;此时,较基准相比,垂直烧结速度和利用系数稍有降低,成品率和转鼓强度分别提高0.60%和1.94%,固体能耗降低1.15 kg/t,达到最优值,烧结烟气CO浓度降低10.91%;表明喷吹蒸汽的进入使得被其他混匀矿包裹燃料中的碳元素充分反应,发挥高温反应的效果显著,进而提高成品率和转鼓强度;同时适宜蒸汽的加入参与到烧结高温带反应,有利于H₂O与C和O₂反应,将还原性气氛的CO转化为CO₂,进而降低CO排放和烧结固体能耗。综合来看,在合理的喷吹制度下,料面喷吹蒸汽可起到烧结过程CO减排和改善烧结矿产质量指标的双重效果。

Effect of steam injection from material surface on output and quality of sinter and CO emissions

With the continuous tightening of the ultra-low emission standard for the pollutants from sintering flue gas in the steel industry, the sintering material surface injection technology has become a new research hotspot due to its potential advantages of energy saving and emission reduction, it is widely considered as a sintering process control technology with certain comprehensive emission reduction effect at present. In order to find out the optimal process system of steam injection on the material surface and to find out the mechanism of the effect of steam injection on the sintering process, in order to realize its industrial application, a sintering raw material of a steel plant was used, the effects of total steam injection rate, injection flow rate and initial injection time on sinter quality and CO emission were studied. The results show that under the condition of 50 kg sinter cup raw material, the best experimental conditions of steam injection on the material surface should be 15 min after 8 min of sintering ignition, 0.02 m3/min of injection flow and 180 g of total injection, the production rate and drum strength increased by 0.60% and 1.94%, the solid energy consumption decreased by 1.15 kg/t, and the CO concentration decreased by 10.91%. The results show that the injection steam can make the carbon in the fuel fully react with other blended minerals, and the effect of high temperature reaction is remarkable, and then the yield and drum strength are improved. At the same time, the suitable addition of steam to the sintering high temperature zone reaction is beneficial to the reaction of H₂O with C and O₂, and the CO in the reducing atmosphere is converted into CO₂, and then the CO emission and the sintering solid energy consumption are reduced. On the whole, under the reasonable injection system, the steam injection can reduce the CO emission and improve the sinter quality.