Tailings Strategies

Learn about thickened tailings disposal strategies at Paste 2014

SRK presentation about thickened tailings disposal strategies given at Paste 2014 conference.Presentation title:  Selection criteria for two alternative thickened slurries to be deposited over conventional tailings: storage capacity and liquefaction

Presentation date and time: Thursday, June 12th at 14:25

Conference details:  Paste 2014, Vancouver, June 8 - 12



Abstract: Depositing thickened tailings over a conventional tailings deposit leads to a raft of considerations and risks relating to the interaction of the two tailings layers, and these must be identified and evaluated before making the significant financial investment involved in changing a disposal system.

As part of a selection process for a thickened tailings disposal strategy that involved placing thickened tailings over a conventional tailings deposit at an existing mine in Mexico, two alternative thickened tailings streams were characterised. One of these was a total tailings product, and the other was a fine product with coarse particles removed. Two issues were identified as key assessment criteria to enable an informed choice between thickening either the fine or total tailings: the evolution of density and pore pressures through self-weight consolidation and the potential for liquefaction of the composite tailings deposit. This paper discusses the considerations and methodology of assessing these two criteria. 

The evaluation process involved a geotechnical laboratory test work program on both tailings materials. The test results provided inputs for a transient large-strain consolidation model and for stress-strain dynamic analyses. The consolidation model results were used to compare storage capacity estimation. These results provided critical inputs for a dynamic evaluation of both tailings composites. Liquefaction conditions were assessed through a dynamic analysis that compared the cyclic shear stress associated to dynamic loads with the mobilised cyclic shear strength of the tailings material. Associated plastic deformations were obtained for each scenario studied.

Speakers:

Nicholas Thompson is geotechnical consultant specialising in tailings, heap leach and mine waste management.Nicholas Thompson, B.Eng (Civil) (Hons.) MIEAust., Consultant (Mine Waste)
SRK Consulting (Australasia)

Nicholas Thompson is a geotechnical consultant specialising in tailings, heap leach and mine waste management engineering. Nicholas has had great exposure to a wide range of alternative designs, from conventional to dry stacks in a variety of commodities and climates. Nicholas has experience in both desktop design and site based roles.


Cameron Hore is a geotechnical consultant specialising in tailings and waste management and heap leach facility engineering.
Cameron Hore, B.Eng (Civil) (Hons.) MIEAust., Consultant (Mine Waste)
SRK Consulting (Australasia)

Cameron is a geotechnical consultant specialising in tailings and waste management and heap leach facility engineering. Cameron has experience with projects from across the globe encompassing a wide variety of commodities, tailings disposal methods and climates. He has been involved in studies from green fields site selection through to closure design and site based geotechnical investigations.


Pepe Moreno has extensive experience in tailings management systems, heap leach pads, and waste rock disposal.
Pepe Moreno, Civil Eng. MIEAust MAusIMM, Principal Consultant (Mine Waste)
SRK Consulting (Australasia)

Pepe Moreno has more than 20 years of professional experience in projects mainly associated with geotechnical/geoenvironmental engineering for the mining and civil industries throughout South America, Africa and Australasia.  Pepe’s experience includes tailings management systems, heap leach pads, waste rock disposal, earth retaining structures, and soil dynamic response.

 

SRK North America