The company announced the findings of the study alongside an updated mineral resource estimate for the project, which is in South Australia. It withdrew its 2021 enhanced feasibility study for the project and initiated the new feasibility study last December, after a review confirmed that the underlying material assumptions had changed.
The new feasibility study reflects an updated mineral resource estimate, as well as incorporating additional drilling, detailed permeability and geometallurgical analysis, actual wellfield performance and advanced reactive transport modelling. Taken together, the company says, this has “materially improved Boss’s understanding of the distribution of uranium mineralisation, permeability, hydraulic connectivity and the geochemical processes controlling uranium recovery”.
Estimated resources now stand at 20.8 million pounds U3O8 at a 100 ppm cut-off (lower than the 250 ppm cut-off in the previous estimate), with 13.7 million pounds in the Indicated category and 7.1 million pounds U3O8 of Inferred resources. As well as the reduction in cut-off grade, the new figure reflects a change in estimation approach and the application of ISR-specific criteria for assessing the reasonable prospects for eventual economic extraction. The updated figure represents a decrease in metal of 15.1 million pounds U3O8 compared to the previous (2019) estimate.
The study also confirms a wide-spaced five-spot, 8 pattern, wellfield design as optimal for the development of the Honeymoon, where in-situ recovery (ISR) – also known as in-situ leach – is used to recover uranium. ISR is a method of mining uranium by dissolving and recovering it via wells. A wider spaced drilling pattern reduces the number of wells and associated surface infrastructure required and lowering the relative cost of development. The wider spacing and refined operational design enabled by deposit characteristics at Honeymoon result in significantly lower acid consumption, while increased effective recoveries enable more of Honeymoon’s extensive lower-grade mineralisation to be incorporated into the production plan, the company said.
Boss CEO and Managing Director Matthew Dusci said the new study “establishes a technically robust pathway for Honeymoon and delivers a fundamental step change in the operation’s cost structure”, and has enabled the wellfields to be redesigned around the characteristics of the orebody. There remains “significant scope” for further optimisations as operating data continues to build, he added, with 45.1 million pounds U3O8 of resources at Gould’s Dam and Jasons Deposit – which are not included in the NFS – providing “substantial potential to increase annual production and extend mine life”.
In its guidance for FY2027 – which Boss Energy says is a transition year as Honeymoon moves from legacy wellfield spacing to the wide-spaced design – the company expects production of 1.25-1.30 million pounds U3O8.
ISR operations began at Honeymoon in 2011, but the mine was put on care-and-maintenance in 2013 by its then-owner Uranium One. Boss acquired the project in 2015.
