The process mineralogy of mine wastes

The discipline of process mineralogy developed through the recognition that metallurgical flowsheets could be optimised by thorough characterisation of the precursor ore mineralogy, mineral associations, grain size and textures. This study presents a methodology for the effective characterisation of mine wastes with respect to Acid Rock Drainage and Metal(loid) Leaching (ARDML) potential, which includes representative sampling, static and kinetic geochemical tests, qualitative and quantitative mineralogical assessments, and numerical modelling to evaluate the source term chemistry related to mine facilities. The applicability of this methodology is emphasized through the necessity of a robust drill core database and a comprehensive mine plan, although limitations due to budget constraints may arise. The omission of detailed mineralogical investigations may result in inadequate understanding of geochemical controls affecting mine waste behaviour, potentially leading to significant financial and environmental consequences due to over- or under-engineering of mine facilities. Case studies are discussed to illustrate the practical application of mineralogy in tackling ARDML prediction and mitigation challenges, especially in the context of waste rock assessment.