Evaluation of cost-effectiveness for coking coals based on multi-indicator grading

The selection of coking coal in integrated steel mills requires balancing multiple quality parameters against purchase costs. A quantitative cost-effectiveness evaluation model is proposed based on six key indicators, ash, sulfur, volatile matter, G -value, Y -value, and CSR/M40, each scored against plant-specific benchmarks using expert-assigned contribution coefficients. A single performance index is derived from the sum of deviations, which is then multiplied by the delivered price to obtain a comprehensive cost-effectiveness (CCE) value; lower CCE indicates better economic performance after quality adjustment. Applying the model to 21 commercial coking coals from a large integrated steel plant in northeastern China, all samples are systematically ranked, and inter-indicator correlations are analyzed. Results show that CSR/M40 exhibits the strongest negative correlation with CCE ( r = –0.71, p < 0.001), while price alone shows no significant correlation ( r = 0.07, p > 0.05). The model successfully identifies that high-priced coals do not always guarantee superior cost-effectiveness; conversely, several moderately priced domestic coals achieve excellent adjusted costs due to balanced quality profiles. The proposed method is transparent, easily implementable in plant-level spreadsheets, and provides a rational basis for procurement optimization. Limitations include the subjectivity of contribution coefficients and the need for strict quality thresholds for critical parameters such as CSR.