From tailings to valuable resources: the use of predictive geometallurgy to quantify the feasibility of tailings reprocessing

The tailings of industrial mineral production are a major environmental and financial burden for mining operations. Because most historic and current beneficiation plants extract only one – or few – commodities contained in the ore, tailings dams should be regarded as anthropogenic ore deposits, i.e., potential sources of raw materials. Their recovery would have a number of associated benefits: effectively reducing the waste volume as well as the environmental burden whilst simultaneously increasing the efficiency of metal / mineral production from a non-renewable resource. In some cases, this may be achieved at minimal cost, since raw materials in tailings dams are already mined, milled and deposited at surface.
Yet, most tailings are low-grade resources; technologies applied in beneficiating tailings need to be well-selected and highly efficient. For this purpose, a sound understanding of the beneficiation characteristics of such tailings needs to be developed. With the latest advances of mineral characterization and data mining techniques, the Helmholtz Institute Freiberg for Resource Technology has been developing a framework that enables predictive geometallurgical studies of tailings materials. This presentation will illustrate three particular parts of this framework, namely (i) resource models that account for mineral processing properties, (ii) economic evaluation of by-product recovery in early stages of projects, and (iii) the use of single particles’ information for modelling mineral processing units. By combining these techniques, we are able to quantify the potential of transforming tailings into valuable resources.