Characterisation of Mine Waste Materials for Improved Management and Disposal Practices

Key Researchers: Stephen Fityus, John Simmons , Olivier Buzzi, Jubert Pineda

PROBLEM DESCRIPTION

Regulators are placing increasingly stringent requirements on mining companies around mine site management and rehabilitation. There are increasing pressures to limit the area of ground disturbance, minimise the distances waste is hauled and make tailings dams redundant. As a consequence, there is a strong incentive to constrain waste dump footprints, and to co-dispose of tailings with waste rock or other on-site materials. The starting point to optimise the handling and storage of waste materials on mine sites is to understand the inherent behaviours of these materials in isolation and in combination. The research includes characterisation of saturated and unsaturated hydraulic properties of waste rock, tailings and natural soils, characterisation of the strength and durability of these materials, evaluation of the evolution of these characteristics in materials during and after mining, exploration of approaches to integrate different materials so as to mitigate undesirable behaviours, or enhance favourable ones.

SCIENTIFIC AND ENGINEERING APPROACHES

• Characterisation of waste rock, tailings, mixed plant rejects and natural topsoils to understand their beneficial and detrimental characteristics, in the contexts of management as wastes, and resources for use in rehabilitation.
• Characterisation of the strength and durability of typical minesite materials
• Calibration of pedotransfer functions to describe the basic material behaviours
• Development of approaches to predict the outcomes of material blending for particular purposes
• Validation of material design principles through field and laboratory testing

APPLICATIONS

• Co-disposal of tailing in-pit with waste rock, instead of in tailings dams
• Optimised dump design
• Final landform design
• Blended soil rehabilitation practices