PASTE & FILTERED TAILINGS
Ensuring tailings safety for QB2 cyclone sand is a common practice in Chile and has proven to be a safe method of construction for large scale structures such as required for this site .
Water is added to reduce the solids contents of the tailings for cycloning to produce sand for the dam construction and deposition into the TMF . The complex deposition system and tailings management maximise the reclaimed water .
Safety and sustainability were at the forefront of WSP Golder ’ s design for the tailings management facility at Teck ’ s Quebrada Blanca Phase 2 copper project in Chile
WSP Golder personnel from six countries contributed to the design of the tailings management facility ( TMF ) for Teck ’ s Quebrada Blanca Phase 2 Project ( QB2 ). Located in northern Chile , QB2 is one of the largest undeveloped copper resources in the world .
When complete , it will be a world-class asset with low operating costs and an initial mine life of 28 years with significant additional growth potential . QB2 ’ s operation incorporates extensive environmental measures including the use of desalinated seawater and a tailings management plan that maximises water recovery in challenging terrain .
WSP Golder designed the TMF and is providing the construction Quality Assurance ( QA ) services . This challenging task required several in-depth designs and various analyses to design a facility capable of handling 140,000 t of tailings per day that will be transported by gravity to the TMF , where the tailings will be separated into fine and coarse fractions . The coarse sand fraction will be used for construction of the storage embankment , while the finer fraction will be deposited into the tailings impoundment .
“ Responsible management of mine tailings is an important part of our business ,” explains Paul Bedell , WSP Golder ’ s Principal , Senior Geotechnical Engineer . “ Having the opportunity to work on a high-profile project like this and leverage our best practices from various disciplines to design this facility is a true honour . The entire team takes this responsibility very seriously , and we are all proud of what has been accomplished : a sound tailings management facility design , aligned with the industry imperative of ensuring safety . This was the result of collaboration with our clients and across our internal international teams , work environments , and languages .”
The Design
In addition to facility embankment design , services included : surface water management design , tailings material classification ( ie cyclone station ) design , and pipeline design for water and tailings distribution with electrical , structural , and instrumentation components .
The TMF will be developed starting with a 35 m high rockfill cofferdam , 120 m high rockfill starter dam , and then the tailings sand embankment will be raised throughout the life of operations . At the end of the 25-year mine life , the tailings facility will be 310 m high . The use of
Project and Client Management
The lifecycle of the project ( pre- feasibility through to construction ) was carried out over five years .
More than 400 WSP Golder personnel contributed to the project , from six different countries and much of the work was in two different languages – a great example of collaboration across cultures and work environments . With any project of this duration and complexity , there were changes to personnel , and throughout the project stages , a concise and direct channel of communication was required with the client and stakeholders . Client expectations were recorded during the project kick-off and robustly tested throughout . It was imperative that the roles of responsibilities of key personnel , such as the Project Manager , Engineering Manager and Technical Leads , were clearly defined and that the team continued to evolve over the project life .
What ’ s next ?
WSP Golder ’ s ongoing work on the QB2 project is in the capacity of construction quality assurance ( CQA ). Construction is expected to take approximately three years , with the mine operations currently planned to be underway in late 2022 .
Starter dam and lined impoundment at QB2 pictured in March 2022 ( courtesy Teck Resources )
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P16 International Mining SUPPLEMENT | JULY 2022