Overhead photo of 2 pyramid-shaped trial pads consisting of light gray waste rock on a mining site. A ladder extends to the top of the closest trial pad. Wrapping around them are light brown dirt roads.
Newmont: Marlin GeoStable Tailings trial pads


​vision
Our VISION is to advance the understanding, development, and implementation of commingled tailings and waste rock to produce GeoStable Tailings, comprising a geochemically and geotechnically stable material, to support the safe and sustainable management of tailings and mine waste rock, improving long-term stability and mitigating environmental and social risks. 


​Strategy


​The basis of the commingled concept combines the two core materials, tailings and waste rock, to a specified mix design ratio for deposition in a single repository. The tailings and waste rock would be blended to produce an engineered material with superior physical and hydraulic properties for the construction of post mining landforms, when compared to the waste rock or tailings separately stores. Ideally, the commingled material would have the strength and compressibility characteristics similar to or better than that of well-placed engineered waste rock piles.
Schematic showing mix ratio – dry density relationship
Schematic showing mix ratio – dry density relationship (after Wickland et al. 2006)
Ternary, triangular diagram in red, green, blue, and purple shades showing typical tailings types
Ternary diagram showing typical tailings types
Furthermore, the commingled material would ideally have a hydraulic conductivity similar to that of tailings with commensurate water retention characteristics, without loss in geotechnical strength. These properties of the commingled material would restrict oxygen entry and water seepage, reducing the potential for acid generation and metal leaching. Finally, placement procedures could be developed such that the commingled material could have a higher density than either conventional tailings or waste rock deposits, thereby reducing the total volume of the waste and footprint. 


​our story
Enhancing the safety, stability, and environmental performance related to tailings management 
Photo of 4 square beds of bright green grass receding into the distance. Each is outlined by black plastic. Surrounding the beds is a barren brown land with a mount of trees in the distance. Vale: Copper Cliffs final test configuration

1. Research

Research has been undertaken in recent years to formulate the mix design theory and design principles, along with laboratory testing, meso scale column tests and field trials. While this work has been published in thesis, refereed journals and international conferences, there is a limited knowledge base to begin implementation of this technology, especially at sites where concentrators have high daily throughput. 
Photo of 2 pyramid-shaped trial pads consisting of waste rock on a mining site. A pile of boulders lies in front and in the background is a paved road with a tractor driving off to the right. A grassy hill sits on the other side of the road.
Newmont: Penasquito GeoStable Tailings trial pads
Overhead photo of 2 pyramid-shaped trial pads consisting of waste rock on a mining site. One of them has a ladder extending to the tops and the other has more vegetation growing atop it. The pads are encased by a light brown road with a smaller road that goes off on the lower left hand corner. Thick vegetation surrounds the outskirts of the road.
Newmont: Marlin GeoStable Tailings trial pads

2. Evaluation

Some of the key areas required for evaluation and development include:
​
  • Testing protocols and scale-up procedures
  • Where to best achieve the mixing (e.g. mill, mid-transport or at the deposit)
  • Methods for transport, blending, mixing and deposition
  • Pilot-scale trials
  • Influence of mineralogy
  • Influence of climatic regimes
  • Methods to assess, compare and validate performance ​
Frontal photo of 2 pyramid-shaped trial pads consisting of waste rock on a mining site. One of them has vegetation growing on all 4 sides and two people stand at the top. The pads are surrounded by barren dirt land.
Newmont: Marlin GeoStable Tailings trial pads (after 2 yrs)