Original Article

Data-driven assessment of large blast furnace operations in India: productivity drivers, raw materials, and benchmarking

¹ O. P. Jindal University, Raigarh, 496109, Chhattisgarh, India
² RDCIS, Steel Authority of India Limited (SAIL), Ranchi 834002, Jharkhand, India

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Received: 28 November 2025
Accepted: 8 May 2026

Abstract

Large blast furnaces (design volume ≥ 3,800 m³) underpin India’s primary hot-metal output, yet operator-oriented quantitative assessments for this cohort remain limited. This study analyses FY 2023–24 annual data from twelve Indian large blast furnaces to quantify how routinely controlled thermal and burden variables associate with working-volume productivity (tHM/m³/day). Given the small cohort (n = 12), a parsimonious ordinary least squares (OLS) model is adopted for interpretability and benchmarking. The final six-predictor model—hot-blast temperature (HBT), oxygen enrichment, slag rate, slag basicity (CaO/SiO₂), hot-metal silicon, and coke ash—accounts for a large share of cross-plant variation (R² = 97.22%; adjusted R² = 93.88%). Higher HBT and oxygen enrichment are positively associated with productivity, whereas higher slag rate, slag basicity, and coke ash show negative associations. Pairwise analyses indicate that higher slag and coke rates co-vary with lower throughput, while gas utilisation (GU) aligns with improved performance and is best interpreted as a diagnostic indicator. Leave-One-Out Cross-Validation (LOOCV) indicates moderate out-of-sample performance (Predicted R² = 65.54%), and the model is therefore positioned as an associational benchmarking framework rather than a predictive tool. On a useful-volume basis, benchmarking against published data for large Chinese blast furnaces (2017) indicates that Indian furnaces achieve moderately higher productivity (∼6–7%) but at the cost of higher fuel consumption (∼5–6%) and substantially higher slag generation (∼20–23%). Despite a remaining temporal gap, the comparison provides directional insights, highlighting slag control and fuel efficiency as key improvement areas.