Experimental research on semi-coke for blast furnace injection

Abstract

The combustion properties and grindability of Shenmu low-rank coal (SM) and its four different semi-cokes were studied by the self-designed equipment and Hardgrove method. The four semi-cokes were obtained under the pyrolysis temperature of 400, 500, 600 and 700 °C, named as SM-400, SM-500, SM-600 and SM-700, respectively. The analyses of nitrogen adsorption, Fourier-transform infrared spectroscopy (FTIR) spectra and Raman spectra were carried out to explain the change in combustion ratio and grindability. The result showed that the specific surface area of samples had an essential effect on the combustion ratio of SM-400 and SM-500. Meanwhile, the grindability depended on the strength of coal matrix, and the augment of pore amounts would increase the grindability. The functional groups and graphitization degree of the same sample were identical with the combustion ratio. With the pyrolysis upgrading temperature increasing, the combustion ratio of sample decreased, corresponding to the decrease in the benzene ring and the increase in graphitization degree. In addition, the thermogravimetric analysis was carried out, and the result was compared against what was shown in the data of combustion ratio. For pulverized coal injection, the combustion ratio was more intuitive and more accurate than combustibility.

Comparison of isothermal and nonisothermal combustion methods when evaluating semicoke for pulverized coal injection of blast furnace

“…Under the same linear heating conditions, the main influencing factors for the combustion performance are the inherent properties of the sample, including the volatile content, pore structure, and microcrystalline carbon chemical structure. 7,21,22 For isothermal combustion, heat treatment results in a more regular and orderly arrangement of the microcrystalline structure; thus, not only the diffusion properties but also damage to the microcrystalline structure needs to be considered. For a DTF, the pore structure has a significant influence on the early stages of combustion.…”

Computational Study of Hot Gas Injection (HGI) into an Ironmaking Blast Furnace (BF)

“…In recent decades, much attention has been given to the implementation of new technologies on the BF. e new technologies include the hot charge of burden materials [1,4,5], injection of novel matters, such as PC [6], oil [7], natural gas [8,9], and hot gas [10][11][12], and use of new burden materials including highly reactive coke [13,14] and carbon composite pellet [15]. ese technologies have been examined at various levels and proved to be useful for improving BF performance.…”