The Possibility of Predicting CRI/CSR of Metallurgical Coke using Cokes Prepared at Laboratory Scale (80 g)

The chemical, physico-chemical and mechanical characteristics of coke are of great importance for the smooth running of blast furnace. Coke reactivity is one of the most commonly applied parameters for evaluating coke quality. The NSC test (ASTM-D5341) is the most widely accepted by the steel industry for this purpose. This method involves measuring the reactivity to CO2 at high temperature (CRI index) and the strength of the coke after reaction (CSR index). The ECE-INCAR reactivity test has also proven to be an effective method at laboratory scale for evaluating the reactivity of a coke. For this test, a smaller amount of sample (7 g) is employed than in the NSC test (200 g). In laboratory scale carbonization test, it is impossible to obtain a sufficiently large amount of coke to perform the NSC test. It is therefore useful to establish a relationship between the quality of the cokes prepared at different scales i.e., semi-pilot (17 kg) and laboratory (80 g), by applying the NSC and ECE INCAR tests, respectively. This will make it possible to predict the CRI/CSR of a coke merely by laboratory scale testing. 22 bituminous coals of different geographical origin, rank and thermoplastic properties, chosen from those normally used by the coking industry, were selected for this study. Carbonization tests were carried out in an electrically heated semi-pilot scale movable wall oven of approximately 17 kg capacity (MWO17). The temperature of the wall (1100 ºC) was kept constant throughout the test. The coke was pushed out 15 min after the centre of the charge had reached 950 °C. The coking time was around 3.5 h. Coals were also carbonized at laboratory scale in a sole heated oven. For each test, a sample of 80 g with a particle size <1 mm was heated from the sole at 1050 °C for two hours. The coke reactivity and mechanical strength after reaction of the semi-pilot scale cokes were assessed by means of the NSC test (ASTM D5341 standard procedure). The coke reactivity of laboratory scale cokes to CO2 was determined by the ECE-INCAR method. A linear correlation with a high correlation coefficient was observed between the CRI and CSR with RECE-INCAR index (r2 = 0.906 and r2 = 0.895) in the cokes produced at semi-pilot and laboratory scale, respectively. Coke reactivity and mechanical strength after reaction (CRI/CSR) can be fairly accurately predicted by applying the RECE-INCAR reactivity test to cokes produced at laboratory scale.

Bibliographic Details

Main Authors:	Vega González, María Fernanda, Díaz-Faes González, Elvira, Barriocanal Rueda, Carmen
Format:	comunicación de congreso biblioteca
Language:	Spanish / Castilian
Published:	2022
Subjects:	Ensure access to affordable, reliable, sustainable and modern energy for all,
Online Access:	http://hdl.handle.net/10261/329990
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