Experimental Investigation of Primary Fragmentation of Coal Particles in a Drop‐DSC

Abstract

Experimental Investigation of Primary Fragmentation of Coal Particles in a Drop-DSCIn the presented work, the fragmentation behavior of 18 coals was investigated under high temperature conditions in a drop calorimeter. It was shown that the fragmentation intensity strongly depends on the coals used but tends to increase with increasing coal rank. Furthermore, it was determined that the fragmentation ratio increases with increasing temperature and particle size. As a requirement, a critical value for temperature and particle size has to be exceeded.

Suitability of pulverised coal testing facilities for blast furnace applications

“…Fragmentation is reported to be caused either by thermal stresses due to intra-particle temperature gradients [11] or by internal pressure gradients from the volatiles emerging during devolatilisation [11,13] or a combination of both. Literature indicates that vitrinite-rich coals are prone to fragmentation [9,10,12,14] since vitrinite is one of the most brittle coal macerals [15]. Kim et al [14] and Friedmann et al [9,10] investigate the fragmentation behaviour of different coal type particles, and both indicate a higher fragmentation probability for anthracite-like coals (high vitrinite content).…”

“…PC heating rates range between 10 5 and 10 6 K/s in the blast furnace raceway [16,17]. Two distinct coal conversion effects can be associated with high heating rates: particle fragmentation [9][10][11][12][13][14] and an increased conversion/reactivity of inertinite [7,[19][20][21]. Investigations of inertinite rich coals revealed that the fusible (reactive) share increases at higher heating rates [7,[19][20][21].…”

“…Literature indicates that vitrinite-rich coals are prone to fragmentation [9,10,12,14] since vitrinite is one of the most brittle coal macerals [15]. Kim et al [14] and Friedmann et al [9,10] investigate the fragmentation behaviour of different coal type particles, and both indicate a higher fragmentation probability for anthracite-like coals (high vitrinite content). Moreover, Friedmann et al [9,10] also indicate that fragmentation increases with increasing heating rates.…”

“…Kim et al [14] and Friedmann et al [9,10] investigate the fragmentation behaviour of different coal type particles, and both indicate a higher fragmentation probability for anthracite-like coals (high vitrinite content). Moreover, Friedmann et al [9,10] also indicate that fragmentation increases with increasing heating rates. Fragmentation due to thermal stresses significantly depends on the particle heating rates and the physical properties of the coal.…”

“…However, aside from Li et al [6,7], limited literature questions the applicability to reproduce blast furnace conditions. Because current knowledge indicates that coal conversion is decisively influenced by conversion conditions [2,3,[8][9][10][11][12][13][14], evaluating coals under different operation conditions is assumed to significantly alter the outcome. Coals evaluated as suitable may cause problems when applied to the blast furnace and suitable coals might be rejected because of misleading evaluation results.…”