Impact of crusher type on coal raw material quality

Abstract

The suitability of coal charge for coking depends significantly on the level of its grinding. At the same time, the quality of the charge deteriorates both large pieces and small ones. The most valuable from this point of view are the 3-0.5 mm size classes. The charge, consisting of coal grains of different sizes and stages of metamorphism, should be thoroughly mixed according to the amount of loading. At the same time, at each point of the volume, the charge will have the same technological properties, which will cause the same parameters of the plastic layer as it advances in a well-averaged loading and the same properties of the coke volume of the piece. Adjusting the optimal particle size distribution of the charge is the most effective method of improving the quality of blast furnace coke, which is very important in the future due to the decrease in the sintering ability of the coal charge, as the share of Zh and K coals in the charge decreases. Regulation of the optimal granulometric composition of the charge is the most effective method of improving the quality of blast furnace coke, this is very important in the future in connection with the decrease in the sintering ability of the coal charge, as the proportion of Z and K coal in the charge decreases. The laboratory study analyzed the effect on the particle size distribution of the coal charge of the design of crushing equipment: models of roller, jaw, impact, hammer, and disintegrator crushers. To obtain a charge with an optimal particle size distribution, it is rational to use selective crushing of only a large part of the charge. This can be achieved by using rotary crushers, in which small fractions pass through the crushing chamber in transit, i.e. without interaction with the working body. To optimize the crushing process, we propose to increase the number of revolutions in a rotary crusher by 20 %, since the result of crushing in a rotary crusher is closest to the optimal one. We also propose an adjusted crushing criterion, which takes into account that the optimal content of the (-0.5) mm fraction.