Boss Resources says it has appointed GR Engineering Services Limited (GRES) as the engineering and lead study consultant for its Honeymoon uranium project definitive feasibility study (DFS).

GRES will quickly ramp up the DFS work programs, due to the significant package of advanced technical work Boss has completed since it obtained the Honeymoon uranium project in South Australia from Uranium One (Australia) in December 2015 and, specifically, since the completion of the prefeasibility study in 2017, Boss said.

Honeymoon is a former-operating mine fully permitted to produce 3.2 MIb/y of uranium for export (one of only four mines in Australia). Based on previous studies, it is expected to require $58 million to ramp up output to 2 Mlb/y, according to Boss. It comes with a 63.3 MIb U3O8 JORC resource.

Work completed to date at Honeymoon includes:

• A scoping study in 2016 for the recommissioning and expansion of the Honeymoon project;
• Prefeasibility Study in 2017 that further refined the proposed strategy;
• Field leach trial (FLT) that demonstrated Boss Resources’ improved leaching approach and validated its proposed ion exchange (IX) process;
• Test work that optimised the process through improved resin elution and precipitation optionality
• Trade-off studies that identified the preferred IX equipment (NIMCIX selected) and further optimised the flowsheet by simplifying the process steps;
• An assessment of the drying and packing facility to provide upgrade options available to Boss to meet the planned production profile, and;
• A preliminary assessment of the work required for the existing plant and infrastructure to meet operation requirements of Stage 1 production.

The DFS is due for completion in November 2019, according to Boss.

Boss Resources Managing Director, Duncan Craib, said: “GRES is a leading engineering and consultancy firm that has delivered multiple mining projects of significant size and scale, both domestically and overseas.”

The appointment continues Boss’ relationship with GRES, which completed the Honeymoon scoping study in September 2016 and the prefeasibility study in May 2017.

The scope for the DFS is based on two stages. Stage 1 includes re-commissioning of the existing SX facility and infrastructure including the various modifications required to improve performance, rectify problems identified during previous operations and make preparation for Stage 2 expansion.

Stage 2 includes supplementing the existing SX facility using a parallel IX process along with the expanded yellowcake drying and packaging capacity and modified raffinate/ground water treatment plant all to produce 2 Mlb/y of U3O8 equivalent.

The company said: “Boss will produce a combined DFS for the Stage 1 – Recommissioning, and Stage 2 – IX upgrade to achieve 2Mlb per annum U308. The DFS will improve on the work done in the prefeasibility study and deliver a Class 3 cost estimate with appropriate detail to achieve an accuracy of ±15%.”

The DFS will report on the design of the leach patterns for the wellfields and associated production scheduling based on these patterns and summarise the test work carried out to date, Boss added. It will also provide updated mineral resource and report on progress made against the updated permits.

The preliminary schedule for the DFS indicates wellfield design will be completed by the end of July, with ion exchange and uranium precipitation piloting due to be finalised by the end of August. Stage 1 reporting is due to be completed at the end of September, followed by Stage 2 at the end of October and the final report by mid-November.