Influence of Structure and Mineral Association of Tuyere-Level Coke on Gasification Process
- PDF / 3,132,530 Bytes
- 11 Pages / 593.972 x 792 pts Page_size
- 10 Downloads / 217 Views
TRODUCTION
AS one of the most important materials for human society, iron is mainly (more than 90 pct[1]) produced by blast furnace (BF) and will continue to be dominated by blast furnace in the near future. Due to the dual pressures of economy and environment, other fuel injection is used to reduce coke ratio such as coal, natural gas.[2] With the increase of BF volume and coal injection ratio, higher coke quality is required. However, the shortage of coking coal makes it difficult to produce high-quality coke.[3,4] In addition, the high-temperature and high-pressure environment in the BF process has an important influence on the degradation of coke quality. Due to the essential characteristics of BF as a ‘‘black box,’’ the complex behavior of coke in BF especially in the raceway zone and hearth is difficult to be characterized directly, but it is essentially important to understand key reactions in the blast furnace high-temperature zone.[5]
MINMIN SUN, KEJIANG LI, HAIYANG WANG, ZIMING WANG, and CHUNHE JIANG are with School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, 30th Xueyuan Road, Haidian District, Beijing 100083, P.R. China. Contact e-mail: [email protected] JIANLIANG ZHANG is with the School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing and also with the School of Chemical Engineering, The University of Queensland, St Lucia, QLD 4072, Australia. KE GUO is with the Sinosteel Metallurgical Engineering & Technology Co., LTD., Beijing 100080, P.R. China. Manuscript submitted April 19, 2018.
METALLURGICAL AND MATERIALS TRANSACTIONS B
The tuyere raceway is a zone where the quality of coke is changed drastically. In this area, coke is rapidly heated and subjected to strong airflow. At the same time, combustion and gasification are impacted by collision and thermal stress simultaneously, causing serious damage to the coke surface.[6,7] There are two major reactions of coke in the raceway: (i) combustion reaction with O2; (ii) solution-loss reaction with CO2 and H2O. The former occurs mainly on the surface due to rapid reaction, leaving its internal strength almost unchanged; while the latter can occur in the inner coke through the pores, reducing the strength of coke.[8,9] The dissections of quenched blast furnace and tuyere-drilling technologies are two important methods to study the changes of coke in the high-temperature zone. The behaviors of tuyere-level cokes have been widely investigated in recent years. Gupta et al. investigated the fines generation and the efficiency in a blast furnace, and suggested the generation of fines was influenced by carbon structure and minerals.[10,11] They also studied the mineralogy and reactivity of cokes in a working blast furnace, and revealed that Silicon Carbide (SiC) were the most notable and common existence state for silicon; ferrosilicon alloys (mainly Fe3Si) was also found in carbon matrix of tuyere cokes.[12] Li et al. analyzed existence state and structures of extracted coke and ac
Data Loading...
