The Influence of Organic and Inorganic Additives on the Specific Electrical Resistance of Coke

Abstract

This study aimed to evaluate the effect of both inorganic (boron carbide nanopowders and silicon carbide (carborundum) and organic lean (petroleum coke) additives on the quality of coke produced in a laboratory furnace, as well as on its electrical properties. Analyzing the results of the quality assessment of the obtained coke, it can be argued that the addition of a fixed amount (0.25-0.5 wt.%) of non-caking nanoadditives allows to regulate the process in the plastic state in order to increase the coke strength. This modification affects the coke quality and has a significant dependence on the grade composition of the coal charge. The use of nanoadditives is especially important for coal charges with poor coking properties. Adding 5% of petroleum coke to the coal charge leads to an increase in the gross coke yield by 1.2-1.3%; a decrease in coke ash content by 0.2-0.3%; an increase in the total sulfur content in coke by 0.15-0.23%; deterioration in both mechanical (P25 − by 0. 1-0.6%; I10 − by 0.1-0.2%) and coke strength after the reaction (CSR - by 0.6-1.0%), coke reactivity (CRI - by 0.2-0.3%), as well as structural strength (SS by 0.3-0.4%), abrasive hardness (AH by 0.7-1.0 mg) and specific electrical resistance (ρ by 0.002-0.007 Om×cm). The obtained data may indicate an increase in the order degree of the coke structure and the appearance of a larger number of nanostructures. In addition, it should be noted that a sharper deterioration in blast furnace coke quality is observed when using a coal charge characterized by a lower coal content of the Concentrating Factory Svyato-Varvarynska LLC.