Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6639730 | Fuel | 2013 | 9 Pages |
Abstract
Changes in particle size distribution and in the degree of graphitization of coke samples from various locations across the tuyere entrance of a blast furnace were examined. X-ray diffraction and a fixed bed reactor were used to measure carbon structure and reaction rate of the coke. The feed coke size was observed to decrease by more than 50% in the descent to the tuyere in the majority of the tuyere-level locations. About 60Â wt.% of the core matter from the “bosh” and “raceway” locations consisted of less than half-size feed coke particles. The percentage of â3Â mm and â0.45Â mm size fractions observed in the recovered drill core material were less than 10Â wt.% and 3Â wt.% respectively particularly around the raceway locations. The graphitization degree of half-size coke particles is shown to be a suitable indicator of the temperature profile of tuyere-level regions of a blast furnace. The degree of graphitization of tuyere-level coke samples showed an inverse relationship with amount of potassium adsorbed as well as with the apparent reaction rate. The carbon structure as well as anisotropic texture of coke fines indicated higher ordering of carbon compared to the half-size cokes from the similar locations. The â0.45Â mm size fraction of fines displayed a large proportion of graphite crystals. The study has confirmed the contribution of surface graphitization of cokes on the fines generation particularly in the “raceway” and “birds nest” regions. The study has implications for using the bench-scale assessment of coke performance and modeling of coke behavior to provide an understanding as to what is likely to occur in an industrial blast furnace.
Keywords
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Chemical Engineering (General)
Authors
Sushil Gupta, ZhuoZhu Ye, Riku Kanniala, Olavi Kerkkonen, Veena Sahajwalla,