首钢504m^2带式焙烧机热工制度的试验研究  

Experimental Research on Thermal Regime of Belt Roasting Machine of 504 m^2 in Shougang

作　　者：夏雷阁[1] 苏步新[1] 李新宇[1] 张建良[1] 赵志星[2] 青格勒[2] 

机构地区：[1]北京科技大学冶金与生态工程学院,北京100083 [2]首钢技术研究院,北京100043

出　　处：《矿冶工程》2014年第3期69-75,共7页Mining and Metallurgical Engineering

基　　金：国家自然科学基金资助项目(51174023)

摘　　要：针对首钢504 m2带式焙烧机干燥制度进行试验研究,结果表明:在干燥温度230℃或以上,风速1.76 m/s干燥时,鼓风干燥3 min的条件下,可以避免下层生球的过湿,提高后期预热焙烧工序的透气性和生球焙烧质量。利用焙烧杯对焙烧温度、时间、粒度分级布料、风速和料层厚度进行模拟研究,实验结果表明:随着焙烧温度和时间的提高、风速的提高以及料层厚度的降低,球团的抗压强度均可得到相应的提高;小粒度的生球布到料层下部,大粒度球布在上面,可以有效改善球团矿的平均抗压强度,降低上下层抗压强度差别。当原料为80%秘鲁矿粉+20%地方矿粉+1.5%膨润土,生球水分为9.6%时,综合考虑,最佳焙烧制度为:料层厚度300 mm;10~14 mm粒级的生球装入料层下部100 mm的空间,料层中部100 mm的空间装混合粒度的球,料层上部100 mm的空间装大于14 mm粒级的生球;预热风速1.7 m/s,焙烧风速1.5 m/s;焙烧温度为1270℃,时间为35 min,在此条件下球团矿的平均抗压强度达到2500 N/P,质量满足超大型高炉的入炉要求。An experimental study was conducted on drying systems of belt roasting machine of 504 m2 in Shougang. Results showed that after drying at the temperature of 230 ℃, or above with forced air at a velocity of 1.76 m/s for 3 mins, the green pellets on the bottom would not be over-wetting, which was beneficial for enhancing the air permeability in the following preheating and roasting processes, as well as better for roasting. A simulation study was carried out using roasting cup on the roasting temperature and time, particle size distribution, forced-air velocity and feed-layer thickness. Results showed that with an increase in the roasting temperature, time and forced-air velocity but a decrease in the feed- layer thickness, the compressive strength of pellets was improved to some extent. With green pellets of small grain size distributed below the feed layer while those of larger size above the feed layer, the average compressive strength of pellets was correspondingly increased, reducing the difference between the upper and lower layer in the compressive strength. As the raw material being composed of 80% Peru iron ore, 20% local iron ore powder and 1.5% bentonite, green pellets with water content of 9.6%, the optimum roasting regime is determined as follows ： thickness of feed layer is 300 mm, green pellets of the size within 10- 14 mm are fed into the space of 100 mm below the feed layer, with green pellets of mixed size fraction in the middle space of 100 mm and those of size larger than 14 mm into the space of 100 mm above the feed layer. The forced-air velocity of air is 1.7 m/s for preheating and 1.5 rn/s for roasting. The roasting process lasts for 35 min at a temperature of 1 270 ℃. As a result, the average compressive strength of pellets reaches 2 500 N/P, meeting the requirement of ultra-large blast furnace.

关 键 词：带式焙烧机 鼓风干燥 焙烧温度 焙烧时间 抗压强度 

分 类 号：TF046[冶金工程—冶金物理化学]