Laboratory-Scale Study of Coal Blend Crushing Fineness and Moisture Effects on Coal Cake Expansion and Heating Behaviour

Abstract— The stamp charge coke-making (SCCM) process is primarily influenced by the technical parameters of the coal blend, with economic factors being secondary. A key challenge in SCCM is determining the appropriate adjustments to blend parameters while anticipating their effect on coke oven health. Among these parameters, the stability of the coal cake plays a vital role in ensuring smooth oven operation and achieving high-quality coke production. Coal cake stability is strongly dependent on the crushing fineness of the coal blend and its moisture content. Excessive expansion of the coal cake can negatively impact oven health by increasing internal gas pressure, thereby accelerating structural deterioration. This study, conducted at Tata Steel, Jamshedpur, evaluates the influence of crushing fineness and blend moisture content on the vertical and lateral expansion behavior of the coal cake. Furthermore, the study examines how varying moisture levels affect the heating rate of the coal cake during the carbonization cycle at a crushing fineness level of 90%. The findings contribute to a better understanding of the interplay between blend preparation parameters and oven performance, supporting optimization of SCCM operations for improved coke quality and oven longevity.