Measurement of the Effectiveness of a Decision Support System for Blending Control of Large Scale Coal Mines

Abstract

Large opencast coal mines require a complex infrastructure to fulfill production demand and quality values. The distinct specifications required by each customer are achieved by blending adjustments. There is limited control in variability. With only partial information available, operation controllers blend coal by empirical approximation, trying to keep quality between acceptable ranges in order to avoid penalizations, shipment rejections or even contract suspensions. When a decision support system (DSS) centralized in a control room is used for blending control, crew operators visualize enhanced displays of the different sources of information, obtaining a holistic perspective of operations. Using a simulator to reproduce the blending sequence, crew operators can experiment with diverse what-if scenarios and develop blending strategies for an entire working shift, in which they also incorporate their own expertise and the knowledge obtained after interpreting the simulation results. The research focuses on the empirical analysis of the effectiveness of the DSS by studying the performance of crew users in different operating scenarios produced with a simulator. The development of a methodology for measuring this effectiveness and its impact in the quantification of controlling the variability of blending represents a significant contribution in the area of quality improvement for coal production. The effectiveness of the DSS for controlling the blending and load out processes has been numerically measured after experimenting diverse simulated scenarios, proving that the difference between estimated and actual quality delivered is narrower when using a DSS, in comparison with the BTU variability obtained from historical data. The strategies that produced better results in terms of control of coal quality variability, maximization of infrastructure utilization, time spent in making decisions and the minimization of risk for penalizations and rejections, were scored proportionally to the benefits obtained.