Throughput forecast modelling over the Life-of-Mine

Author(s) L. Brennan, Y. Quan, R. Hayashida, W. Valery, T. Farmer, B. Bonfils, K. Duffy, A. Jankovic

Hatch has developed forecast models for predicting Life-of-Mine (LOM) circuit throughput for a number of operations worldwide. These models can be used to predict variations in future operating throughput arising from changes in ore characteristics, mine planning, blending strategies, and operating strategies, thereby improving process stability and helping to maximise profit over the LOM. In this paper, Hatch shares three case studies of throughput forecast modelling and discusses the main results, model precision, and associated challenges with the methodology, and provides a comparison of predicted plant performance with operational data. Hatch’s forecasting methodology considers the effect of ore characteristics and blast fragmentation on the entire feed particle size distribution (PSD) to the comminution circuits. Site-specific Morrell power-based models are also used to capture the key factors contributing to plant throughput. These include the proportion of each ore type in the feed blend, the characteristics of each ore type (hardness and breakage characteristics), product size targets, and equipment specifications. Data is then collected (often during Mine-to-Mill (M2M) optimisation projects) and used to validate the power-based throughput forecast model against historical observed ore hardness and plant throughput. Outputs from site geological and geotechnical/geometallurgical block models, such as the distribution of the various ore types and their hardness, plus mine planning information are then used to predict the throughput on an annual basis over the LOM. The power-based equations that predict comminution circuit specific energy are also tuned to reflect the recommended mine and eplant optimisation strategies, thus the model can reflect not only current practices, but also be used to investigate potential optimisation opportunities.