大孤山球团厂回转窑结圈机制与抑制措施研究

Study on the intrinsic relationship between pellet ore propertiesand mineral phases of rotary kiln nodules

氧化性球团回转窑热工制度优化与结圈抑制,对提高球团产量和质量、促进高效低耗冶炼具有重要意义。通过对大孤山球团厂窑头球、窑尾球、成品球和结圈物的矿物组成和显微结构分析发现:频繁结圈期间,球团内晶粒间连晶固结较差,各工序球团强度较低;球团碰撞脱落的粉末和煤粉燃烧产生的灰分在结圈物中多以铁橄榄石液相和钙镁辉石液相存在;可通过优化原燃料资源质量、改善配矿结构、提高各工序球团强度、稳定窑内热状态等技术手段,有效抑制回转窑结圈。

The optimization of the thermal regime of the rotary kiln for oxidizing pellets and the suppression of knotting have great significance to improve the quality of pellet production and promote efficient and low-consumption smelting.The analysis of mineral composition and microstructure of kiln head balls,kiln tail balls,finished ball and nodules in Dagushan pellet plant reveals that during frequent nodules,the intergranular crystalline consolidation in pellets is poor and the pellet strength in each process is low;The powder dislodged from the pellet collision and the ash generated from the combustion of coal powder are mostly present in the liquid phase of iron olivine and calcium magnesium pyroxene in the nodules;The ringing of rotary kiln can be effectively inhibited by optimizing the quality of raw fuel resources,improving the ore distribution structure,increasing the strength of pellets in each process and stabilizing the thermal state of the kiln.