在当代钢铁工业"零排放"的追求理念下,烧结粉尘和高炉粉尘是炼铁厂重要的二次资源。这两种粉尘颗粒因经历过高温冶炼过程而具有结晶完整及表面活性低的特点。在空气和水两种介质下,利用行星球磨机,采用激光粒度、扫描电镜、X射线衍射和红外光谱等手段考察了烧结粉尘和高炉粉尘的机械活化机制。研究结果表明,随着活化时间的逐渐延长,两种粉尘的粒度均逐渐减小,赤铁矿物相峰强逐渐减弱,晶块尺寸逐渐减小,晶格畸变、位错密度、无定形化分数和机械力储能逐渐增加;烧结粉尘的湿磨效果较好,而高炉粉尘更适合于干磨;活化后的烧结粉尘颗粒比高炉粉尘颗粒更易发生团聚;在行星湿磨30 min的条件下,烧结粉尘的平均粒度即可达到3.3μm,同时其晶块尺寸减小40%,位错密度为4.8×10^(14)m/m^3,无定形化分数为21.3%,总储能为126 k J/mol;在行星干磨30 min的条件下,高炉粉尘的平均粒度即可达到4.1μm,同时其晶块尺寸减小28%,位错密度为9.8×10^(14)m/m^3,无定形化分数为14.8%,总储能为229 k J/mol。
The heat loss and its,distribution are of great importance for the calculation and simulation of COREX process. Based on Baosteel COREX process, a method was applied to measure the heat loss of the furnace shell, the accessory equipments and the cooling water system. Then, a static model was established based on the measured heat loss of COREX process. The results showed that the main heat loss of furnace shells took place at the dome of the COREX melter-gasifier and the reducing gas entrance position of the shaft furnace while the main heat loss caused by cooling water occurred at the tap hole area. And the heat loss caused by cooling water accounts for about 85% of the total heat loss in COREX process. The measured total heat loss for producing every 1 t hot metal was 542. 164 MJ, which accounted for about 92 % of the theoretical total heat loss.
Wei SHENSheng-li WUMing-yin KOUKai-ping DUYing SUN
