Prediction of Sulfidic Waste Characteristics

Inadequate prediction of acid rock drainage (ARD) can result in the reputational damage of mine operators, the spending of significant costs for post-closure management and lasting impacts to ecosystems. Instead, accurate prediction of ARD will allow a reduction of environmental risks and associated financial liabilities. At present, the mining industry use a range of static and kinetic chemical tests to measure the balance between the acid generating and acid neutralizing potentials of mine waste materials. The resulting data are used to prepare risk assessments and design waste classification schemes. However, associated with these established tests and practices are several shortcomings including: inadequate sampling; performance of a limited number of tests; late initiation of kinetic trials; classification using restricted waste classification categories; and no consideration given to biological and physical parameters that can influence ARD formation. Therefore, current practices only provide a broad indication of ARD potential over time. Fundamentally, ARD is a multifaceted process controlled by several variables, and therefore new tests and protocols developed in this area must reflect this.