Managing ARD potential through mine planning and mineral processing practice

This paper suggests that the time is ripe for the development of a robust methodology for including acid and metalliferous drainage potential in the mine plan. This will be done by developing quantitative virtual and direct measures of drainage potential which have the necessary characteristics for inclusion in the block model of the mine. The methodology will lead to a more accurate valuation of the project, improved mine design, and optimal scheduling. There are sites where ARD potential is included in the block model now, but these are the exceptions rather than the rule, mainly through lack of an established methodology including sampling and testing protocols.

The enabling technologies needing development are mainly in the area of material characterisation, and use can be made of the very sophisticated automated quantitative mineralogy, textural and minor element instrumental methods now available.

This paper discusses the background to the problem, particularly in the context of a major research programme already underway to incorporate mineral processing attributes into the block model, which is likely to provide generic outcomes useful to the present objective. It considers the needs and methodology of mine planning, and critically reviews the current methods of testing for ARD1 potential. A case study demonstrates deficiencies in these methods. The potential role of mineralogy and other material characterisation methods is reviewed in detail, and a number of possible mineral processing strategies to mitigate drainage potential are considered. A more comprehensive block model would assist in the selection of such strategies in particular cases.

The paper closes by suggesting the research topics needed to achieve success, and development of a research project to address these is underway. A multi-disciplinary approach is essential if this ambitious but rewarding vision is to be realised.