摘要
为解决转底炉工艺工程化过程中遇到的问题,进一步优化工艺流程和技术参数,本文通过化学分析等手段明确含锌粉尘原料的理化性质,利用控制变量法分析球团成球性能和还原过程中金属化率的影响因素,通过分析二次粉尘的化学成分及物相组成推断换热系统中黏结物的形成机理,并对不同煤气作为燃料用于转底炉的能效进行对比分析。结果表明:当混合粉尘水分质量分数为12%、膨润土质量分数为5%时,采用强力混合机+对棍压球工艺生产可满足造球系统要求;在211~314℃条件下干燥脱水,生球的临界含水量为3.35%;当温度高于1 300℃时,球团的金属化率可达到85%以上,当碳氧比高于0.9时,球团的金属化率可达到70%以上;通过减少生球团中KCl质量分数可有效改善二次粉尘在换热系统中的黏结堵塞问题;在相同工艺条件下,使用高炉煤气、转炉煤气和发生炉煤气的能耗比焦炉煤气高约15%~20%。本文研究的基础数据可为转底炉工艺设计及应用提供借鉴和参考。
In order to solve the problems encountered in the process engineering of rotary hearth furnace,and further optimize the process flow and technical parameters,the physical and chemical properties of zinc-containing dust raw materials are determined by chemical analysis,and the influencing factors of pelletizing performance and metallization rate in reduction process are analyzed by control variable method.The formation mechanism of adhesive in heat exchange system is deduced by analyzing the chemical composition and phase composition of secondary dust,and the energy efficiency of different gases used in rotary hearth furnace is compared and analyzed.The results show that when the moisture mass fraction of mixed dust is 12% and bentonite is added with 5%,the production process of strong mixer+counter-bar pressing ball can meet the requirements of pelletizing system.Under the condition of drying and dewatering at 211~314 ℃,the critical water content of green pellets is 3.35%;When the temperature is higher than 1 300 ℃,the metallization rate of pellets can reach over 85%,and when the n(C)/n(O) ratio is higher than 0.9,the metallization rate of pellets can reach over 70%.Reducing KCl mass fraction in green pellets can effectively solve the problems of secondary dust sticking and blocking in heat exchange system.Under the same process conditions,the energy consumption of blast furnace gas,converter gas and generator gas is about 15%~20% higher than that of coke oven gas.The basic data can provide references for the process design and application of rotary hearth furnace.
作者
李岩
赵志坚
冯怀萱
王静松
佘雪峰
薛庆国
LI Yan;ZHAO Zhijian;FENG Huaixuan;WANG Jingsong;SHE Xuefeng;XUE Qingguo(State Key Laboratory of New Technology of Iron and Steel Metallurgy,University of Science and Technology Beijing,Beijing,Beijing 100083,China)
出处
《烧结球团》
北大核心
2022年第6期106-115,145,共11页
Sintering and Pelletizing
基金
国家重点研发计划资助项目(2019YFC1905705)
广东省科技计划资助项目(GDK2020002)。
关键词
转底炉
含锌粉尘
直接还原
二次粉尘
能效分析
rotary hearth furnace
zinc-containing dust
direct reduction
secondary dust
energy efficiency analysis
