Dr Nelson Amoah
Western Australian Operations Manager
ATC Williams

Nelson is a technical and operations leader in multidisciplinary environments with over 30 years’ experience in major project management, civil, geotechnical, process and non-process infrastructure design, tailings dam engineering and mine closure. A versatile engineer, Nelson draws on global experience in the resources sector across commodities such as gold, copper, nickel, bauxite/alumina, hematite and magnetite iron and lithium.
He has worked in engineering consulting, mine development and operations management in Africa, North America, Australia, Asia, and New Zealand. Nelson has played leading roles in the development of very large tailings facilities globally and achieved significant expertise in conventional and non-conventional tailings engineering from planning, design, construction, operations management, governance, and closure.
Highly regarded as a global technical leader in the field of filtered tailings stacking (commonly referred to as dry stacking), Nelson spent 10 years at Karara Mining in the design and operations management of the first major magnetite mining and processing operation in Australia. A novel part of this operation is the large-scale tailings filtration and stacking of filtered tailings (non-conventional tailings) which is currently the largest in the world in terms of tailings quantities filtered and stacked (>30,000 t/day). He led pioneering research, investigations, planning, engineering design, installation of tailings dewatering and material handling, and operations management of this novel tailings stacking facility. He has contributed to several technical forums and short courses on tailings filtration and stacking over the past decade.
He has worked for major asset owners including Tianqi Lithium Energy Australia, Karara Mining, Newmont Mining, BHP, and major consulting engineering companies including Lycopodium and GHD. He joined ATC Williams in November 2023 as Western Australia operations manager.
He is a fellow of Institution of Engineers Australia, a chartered professional engineer, and member of American Society of Civil Engineers. Nelson holds a bachelor’s degree (Ghana), master’s degree and PhD (Canada) and MBA (Australia).

Presentation title: The place for filtered tailings and stacking in the search for safe and sustainable tailings management

Abstract:

Tailings dam failures have become a tragic part of the mineral processing industry, and the last decade has witnessed dam failure events (mostly upstream raised) that have shaken the global community due to the number of human lives lost and the scale of environmental destruction. The amount of water in the tailings material deposited and in the tailings storage facilities during operation – in combination with improper operations management of tailings water – have contributed to  tailings dam failures.  

The risks associated with slurry deposited tailings in conventional tailings dams have generated intensive debate and interest in improved and alternative methods of managing tailings such as dewatered (thickened paste and filtered) tailings for safe and sustainable tailings management. However, the transition to low water content tailings such as filtered tailings (commonly termed dry) continue to be challenged by uncertainties and misunderstandings on the issues and benefits in terms of feasibility, engineering performance, scale of operation, cost effectiveness etc. The debate on filtered tailings and stacking exists in both mining businesses and tailings technical community. 

To contribute to the debate, the paper discusses practical insights obtained from the development of the largest filtered tailings storage facility, from dewatering processes of thickening and filtration, material handling and disposal and operation management of the filtered tailings storage facility.  Key learnings in the design process, performance criteria, in situ behaviour of the filtered tailings, facility operational control requirements, cost effectiveness and some critical success factors are discussed.