Study of the agglomerate crushing process and industrial development of an advanced rotary crusher

Abstract

The process of blast furnace production relies heavily on the quality and composition of its charge materials, among which iron ore sinter plays a crucial role. The consistency in the fractional composition is intrinsically linked to the method employed for their fragmentation. This fragmentation, or crushing, is influenced by the type of load applied and is inherently dependent on the design and functionality of the crushing machinery utilized. Based on the mechanics of the crushing process, a mathematical model has been developed to describe the interaction between the sprocket teeth and the material being crushed. This model aids in determining the optimal conditions that facilitate the material entry into the active crushing zone of a toothed rotary crusher. Through this analysis, it becomes evident that rotors outfitted with chevron and spiral-configured sprocket teeth significantly outperform those with a linear arrangement. Experimental investigations into the agglomerate crushing process have shed light on the outcomes of different deformation methods. When subjected to compression deformation, it was observed that the resulting material contained 17.2% of fines smaller than 5 mm and a -10 mm fraction amount to 31.1%. Conversely, a more controlled process emerges during stretching in bending, which remarkably reduces the −10 mm fraction to only 1.6%. Building upon these insights, a modernized toothed rotary crusher featuring a nonlinear rotor was developed and implemented in the sintering production of Branch No. 1 AISW of SMMC. The introduction of this advanced crusher led to notable improvements in the screening process of hot sinter. After employing this upgraded machinery, there was a 2–4% increase in the amount of return material alongside a significant 6–7% reduction in screenings during the classification stage on the conveyor path for supplying blast furnace No. 1 with charge materials. Moreover, this optimization ensured the elimination of oversized pieces, specifically those exceeding 80 mm.