Optimal paste backfill specification development

Abstract

Optimisation of paste backfill specifications is an area of development in mine backfill operations and is practiced at several sites, with backfill mixtures tailored specifically for each stope. This, however, remains the exception rather than the rule across the industry. Often mines employ suboptimal backfill recipes which do not properly leverage the three principal components of a backfill specification, namely: strength, rheology, and curing time. This is compounded by limitations in material characterisation data and the means to develop and integrate this within reliable hydraulic models.Developing a strategy for determining this unique specification provides opportunities for improved backfill reticulation operation and binder minimisation while ensuring that the performance of the backfill aligns with the mining requirements and schedule.The paper describes how, through the use of material test work data, relationships linking these three performance criteria together can determine the optimal paste backfill specification. Case example data is used to demonstrate the analysis process and how a software solution developed by Paterson & Cooke can be used to enable its application in everyday operation.