TAILINGS
Pipe loop test area at the Weir Technology Hub in Venlo , Netherlands
pumps or centrifugal pumps depending on the dewatering performance of the thickener . Weir then weighs up the trade-offs – including operational fluctuations – to establish a risk profile and assess both the capital and operational costs .”
At the same time , if productivity targets aren ' t being met , alternative operational approaches can be explored . “ This might include , for example , assessing the integration of new technologies to enhance efficiency . This phase primarily generates input data for further indepth studies .”
In essence , Weir says its testing methodology is two-fold : optimising existing processes by derisking operations and exploring innovations to boost productivity . Ultimately , both these approaches facilitate informed decision-making in tailings management .
As an OEM , Weir is often at the forefront of the developments , which then inform many trends within the industry . One example of this is the Terraflowing™ process , a proprietary solution developed at the Weir Technology Hub in Melbourne , which produces an engineered tailings product in which the properties are tailored to meet the specific requirements of the Tailings Storage Facility ( TSF ).
This involves customising the water content to allow for pumping what are often significant distances , while also employing decision trees to determine optimal flow sheets , such as utilising cyclones for hypermobility zones .
Vlot and Kruyswijk conclude : “ As the ICMM roadmap makes clear , many of the challenges that tailings present will only be solved with collaboration . For Weir , being a valued industry partner takes many forms – harnesses advanced technologies to provide customers with predictive insights into pipeline operation , enabling early detection of anomalies and optimising equipment efficiency , just to mention a few – but , importantly , these technologies , services and solutions fit within its broader commitment to help miners reduce their waste and produce a more manageable product .”
Innovation in Tailings Dewatering – Anglo American & WSP
WSP ’ s Mark Bruton , Mine Waste Europe Lead & James Purrington , Associate Tailings Engineer , last year outlined how the development of an innovative new tailings technology , hydraulic dewatered stacking , is advancing the mining industry ’ s commitment to improvements in stability , water recovery and closure of tailings facilities .
Tailings is an area of mining where the industry is constantly seeking new approaches and ideas . They are an inevitable byproduct of the mining process but require extensive management to protect people and the environment . Recent catastrophic failures have rightly resulted in enhanced oversight and calls for change . Through the Global Industry Standard for Tailings Management ( GISTM ), mining companies are now actively adopting new levels of governance to increase the safety of tailings storage facilities ( TSFs ).
They state : “ Governance alone is not the solution , however . Identifying new methods and technologies for managing tailings is imperative . Those methods must be robust , practical , and economical at scale ; ideally , they should also minimise any increase in operational complexity at the facility . An innovative tailings management concept , hydraulic dewatered stacking ( HDS ), appears to tick all these boxes . It is being developed by global mining major , Anglo American , who partnered with WSP to conceptualise and design the new approach .”
The idea for HDS was born out of the adoption of coarse particle recovery ( CPR ) at Anglo American ’ s El Soldado copper mine in Chile . CPR results in a free-draining sand byproduct , which the mine believed could be put to beneficial use . Reaching out to WSP , Anglo American ’ s question was a simple one : could this waste be turned into a resource ? The answer quickly became a resounding yes .
The concept devised by the combined Anglo American-WSP team uses CPR sand as a filter , codisposing it with tailings to deliver passive drainage and gravitational dewatering of the tailings . The water is then managed separately for re-use in the mining process .
The HDS concept thus delivers benefits well beyond just finding a use for CPR sand . The three main advantages studied relate to water , stability , and closure .
Conventionally deposited tailings contain a large amount of entrained water with supernatant water typically managed on the surface . This results in large amounts of water being lost through entrainment and evaporation : water losses from tailings are in fact the most
Hydraulic Dewatered Stacking ( HDS ) at Anglo American ' s EL Soldado operation in Chile
52 International Mining | APRIL 2024