Abstract: To address the issues of overgrinding and low yield of qualified size fractions during the grinding of carbonate containing iron ore,this study investigated the effect of grinding media shape on grinding characteristics using a high-silicon, high-carbonate iron ore from the Anshan area as the research object.Grinding tests were conducted with spherical,short cylin drical,and short frustum conical media on both narrow size fractions and full size fraction feed.The grinding performance was systematically evaluated using particle size distribution,the Rosin-Rammler particle size characteristic equation,grinding kinet ics models,overgrinding index (content of -0.01 mm),and qualified size fraction content (0.1~0.01 mm).Based on these evaluations,media size combination was optimized following the linear superposition principle.The results indicate that spheri cal media exhibit the highest grinding efficiency but also the highest overgrinding index and poorer product uniformity.Short cy lindrical media yield the best product uniformity and the lowest overgrinding index,albeit with lower grinding efficiency.The short frustum conical media show intermediate performance.The optimized media combination scheme—“spherical (ϕ40 mm) + short cylindrical (ϕ25×30 mm) + short cylindrical (ϕ15×10 mm)” with a mass ratio of 2∶1∶1—achieves a balance be tween high grinding efficiency and reduced overgrinding,while increasing the qualified size fraction content.This synergistic optimization provides a more favorable feed size distribution for the subsequent beneficiation of carbonate-containing iron ore.

Key words: carbonate-containing iron ore,grinding media,media size combination,overgrinding index,qualified size frac tion,grinding kinetics