RATIONAL TECHNOLOGICAL PRINCIPLES OF RECEIVING COKE WITH SPECIFIC INDICATORS OF SPECIFIC ELECTRICAL RESISTANCE

Abstract

The paper presents the main technological principles of obtaining coke with two levels of given specific electrical resistance (PEO) for blast furnace and ferroalloy production, respectively. PEO is an important characteristic of coke, which is closely related to its readiness and the whole complex of metallurgical properties. As readiness increases, the electrical resistance of coke decreases simultaneously with the improvement of its consumer properties. Therefore, the specific electrical resistance determined under standard conditions is an objective characteristic of coke readiness. On the basis of the requirements for the properties of coke of improved quality, the concept of production of high-quality coke was theoretically justified and formulated. The technological and physicochemical factors of production that significantly affect the indicators of specific electrical resistance are analyzed, such as the raw material base of coking (grade composition of the charge), regime and technological factors (temperature regime of coking, volume of the sub-vault space, speed of coking), yield of volatile substances, humidity, cohesiveness and the degree of grinding of the charge, the average reflectivity of vitrinite. Also, the quality indicators of the obtained coke are significantly influenced by the hardware and design features of coke ovens, the presence or absence of thermal preparation of the charge and coking technology (tamping, continuous layer coking). The analysis of the technological requirements of consumers for coke with different levels of specific electrical resistance made it possible to develop rational levels of technological parameters for the production of coke with given PEO values, in particular blast furnace coke with low resistance and ferroalloy coke with high resistance, and a rational set of techniques for post-furnace preparation of coke for various directions of its use in compliance with the requirements of specific consumers. In particular, by grinding the largest (and least ready) classes of blast furnace coke, its characteristics can be improved. With the help of which the readiness and the entire set of consumer properties of blast furnace coke are evaluated. At the same time, such an operation should not be performed for ferroalloy coke, as it reduces the specific electrical resistance of coke and the efficiency of ferroalloy electric furnaces.