July 2022
PASTE
An INTERNATIONAL MINING Supplement
& TAILINGS 2022
An onsite photo of FLSmidth ’ s E-CAT™ Clarifier-Thickener , which combines optimised flocculation , high-rate clarification and highdensity thickening in a single unit www . flsmidth . com
International Mining 2 Claridge Court , Lower Kings Road Berkhamsted , Herts . HP4 2AF , UK Tel : + 44 ( 0 ) 1442 870 829
www . im-mining . com
An INTERNATIONAL MINING supplement
PASTE
& TAILINGS 2022
IFC : Mathew Cook of Hawk Measurement Systems reviews Multi-Variable Fibre Optic Sensing Monitoring Solutions for leakage detection in HDPE tailings pipes P2 : Dave Meadows , CTO at Bechtel Mining & Metals , discusses the tailings way forward with a focus on filtered tailings P4 : IM Editorial Director Paul Moore talked to Diemme Filtration about application of its technology to two specific tailings areas – iron ore and bauxite P6 : Paul Moore caught up with FLSmidth ’ s Ken Rahal – Director of Tailings Solutions ; and Fred Schoenbrunn , Global Director for Thickeners P8 : Dennis Zink , Global Product Manager at McLanahan Corporation reviews types of dewatering solutions and argues that plate filter presses come out on top P10 : Jerold Johnson & Brad Bentley of WesTech Engineering , LLC talk about how paste and thickened tailings facilities stand the test of time P12 : Todd Wisdom , Geoff Seale , David Romo and Rachel Jansen from Paterson & Cooke discuss the basics of thickening science and test work P15 : Since the origins of the company , ABEL says it has continuously worked to offer a suitable and complete range of pumps in the mining sector P16 : Safety and sustainability were at the forefront of WSP Golder ’ s design for the Tailings Management Facility at Teck ’ s Quebrada Blanca Phase 2 IBC : Job Kruyswijk , Manager Integrated Slurry Solutions , Weir Minerals , tackles the subject of getting pump choice right for backfilling projects
Pipeline sensing
Mathew Cook of Hawk Measurement Systems ( HAWK ), Australia reviews Praetorian Fibre Optic Sensing Monitoring Solutions for leakage detection in above ground High Density Polyethylene ( HDPE ) tailings pipes
No matter what you mine or what material you process , waste disposal will always be a significant aspect of your operation . The tailings by-product of mineral or coal processing is part and parcel of the refinement process . Often it is possible to use old workings and pits as a final resting place for tailings , other times specific structures like tailings dams ( the largest engineered structures on earth ) are constructed and are used as a location of final storage of tailings .
Depending on location and the mineralogy of the operation , tailings often pose a large amount
of risk to all stake holders in an operation , not
only due to the repercussions of tailings dam failures , but to the potentially toxic nature of the tailings themselves . All parts of a tailings distribution and management system need to be monitored so that they do not have a negative
impact on production , infrastructure , equipment , personnel , landowners or the environment .
Until now , traditional visual inspection
methods or inaccurate mass balance
instruments have been used to determine pipeline condition ; however , with the advances in modern computing and laser technology , Fibre Optic Sensing ( FOS ) systems are now economical ways to fully automate this process without the need for any services in the field .
Tailings pipelines
Part of any tailings management system will include a method of getting the tailings slurry to the final location and ( due to the need to change locations every few years ) will typically be an above ground pipeline . Due to the abrasive nature of these materials and the requirement for flexibility of the pipeline material
when laid on the ground , these pipelines are typically constructed of a reinforced plastic such as High Density Polyethylene ( HDPE ).
As a pipeline material , HDPE is an excellent candidate for tailings pipelines due to a number of factors including : n Low cost n Light weight n Easy jointing n Excellent abrasive resistance n Flexible shape n Corrosion and Chemical resistance n Recyclable / reusable
Pipeline failure
Even with all of these advantages , HDPE is not a perfect material and failures do occur . These failures generally fall under one of four failure methods : n Accidental damage : failure due to an external energy source such as site equipment impact or damaging earth movement n Slow crack growth : a natural failure mechanism of HDPE ; Difficult to detect as it occurs from the inside out ; strain , stress and temperature extremes are contributing factors n Rapid crack progression : an imposed failure , attributed to high pressure spikes in the fluid either due to blockage , overpressure from pumping systems or water hammer effects from valve shut off n Joint failure : substandard or naturally imperfect joints can be a site for thinner pipe sections , which may deform as above and / or fail as an elastic / plastic failure One of the biggest issues facing HDPE