Legacy tailings storage facilities exist within operating mine sites across Australia. These tailings
storage facilities are often viewed as rehabilitation liabilities but with considered assessment may
prove to be a resource. Extraction of such a resource might add value to operations by providing
cash flow during the development of new mines; providing supplementary mill feed for existing mines
undergoing step changes in operations; and supporting mine closure activities.
Hellyer Gold Mines is successfully extracting and reprocessing sub-aqueous material from legacy
tailings storage facilities at their Hellyer operation in north-west Tasmania. The Hellyer tailings
storage facilities contain poly-metallic material from the Hellyer and Fossey underground deposits
dating back to the 1980s as well as material from tailings reprocessing activities by other operators
of the Hellyer site. Hellyer Gold Mines is reclaiming sub-aqueous material using cutter-suction
dredgers and reprocessing on-site.
Hellyer is the only operation of its type in Australia and few such operations exist worldwide. Key
learnings around the estimation of a resource for legacy tailings storage facilities have been acquired
at Hellyer that can be applied to the assessment of other tailings storage facilities.
The application of dredging as a mining method at Hellyer is delivered through collaboration with
experts from outside the mining industry under the direction of a mining engineer. Key elements
required for the planning and delivery of safe and efficient dredging inside tailings storage facilities
have been identified at Hellyer and are presented to provide a road map to the development of other
dredging operations.