Tag Archives: Arrow

Hatch engaged to take NexGen’s Rook I uranium project forward to FEED stage

NexGen Energy has awarded the engineering, procurement, and construction management (EPCM) contract for the front-end engineering design (FEED) stage of the Rook I uranium project in Saskatchewan, Canada, to Hatch, with work well underway.

Hatch, NexGen says, is a leader in project management and engineering and has extensive experience delivering mining projects in Saskatchewan and across Canada.

The awarding of the EPCM contract comes at the conclusion of a tender process involving multiple globally recognised industry firms, according to NexGen. Integrating fully into the owner’s team, Hatch is responsible for providing NexGen with engineering, procurement and execution planning services, along with supporting overall project management.

Following the completion of the Rook I feasibility study in February, NexGen is transitioning into the next stage of advanced project development with the commencement of the FEED stage. This feasibility study outlined a 1,300 t/d operation processing an average feed grade of 2.37% U3O8 and average uranium oxide production of 21.7 MIb/y over the life of mine of 10.7 years from the Arrow deposit.

In line with the optimised project execution strategy, the FEED stage will advance overall engineering to a 40-45% level of completion with associated cost estimate, fully define long-lead procurement actions, and further refine execution planning to prepare the project for the pending construction stage, NexGen said. This FEED stage is scheduled for completion in the September quarter of 2022 and will be undertaken concurrently with the engagement, Environmental Assessment and Licensing workstreams.

The 2021 site investigation program is advancing safely and is planned as a pre-cursor for FEED. Surface investigation field work is now complete, which consisted of test pits and sonic boreholes in locations of planned infrastructure. The collection of confirmational geological, geotechnical and hydrogeologic characterisation data is nearing completion, and early analysis of this data has validated the current designs established in the feasibility study and confirms the understanding of the rock mass proximal to the underground infrastructure and underground tailings management facility, according to NexGen.

Leigh Curyer, Chief Executive Officer, said: “Advancing into the FEED stage of development is another exciting milestone for the company, and we’re pleased to welcome Hatch to NexGen’s growing high performance team in advancing the Rook I project towards the start of construction. Hatch’s exemplary reputation in the global mining sector and deep understanding of value-driven project delivery aligns perfectly with NexGen’s commitment to elite standards and is a key step in the development of this leading global resource project. In parallel, the drafting of the project’s Environmental Impact Study and licensing workstreams nearing completion, together with regional exploration targeting new zones of potential ‘Arrow-type’ mineralisation, further exemplifies the NexGen team’s commitment to the successful execution of multiple workstreams.”

NexGen marries ESG and financials in Arrow uranium project feasibility study

NexGen Energy CEO, Leigh Curyer, says the company’s Rook I uranium project has earnt its place as one of the “leading global resource projects with an elite ESG profile” after the publication of feasibility study results on the project’s Arrow deposit in the Athabasca Basin of Saskatchewan, Canada.

The study was completed jointly by consultants including Stantec, Wood and Roscoe Postle Associates (now part of SLR Consulting), with other technical inputs completed by sub-consultants.

Financial highlights from this study included an initial capital bill of C$1.3 billion ($1.03 billion) repaid with a post-tax net present value (8% discount) of C$3.47 billion based on a $50/Ib uranium price. From years 1-5 average annual production was due to come in at 28.8Mlb of uranium oxide, with average production over the life of mine of 10.7 years of 21.7 MIb/y.
The company laid out plans for a 1,300 t/d mill processing an average feed grade of 2.37% U3O8.

Listed within the “top five feasibility study outcomes” was enhanced environmental performance, with NexGen saying an optimised facilities layout had reduced the project footprint by around 20% and lowered on-site personnel transportation and ore haulage.

Optimised shaft sizing, water usage through advanced water recycling, and plant engineering reflected elite environmental standards, it added.

“With respect to the proposed shaft, mine workings and underground tailings management facility (UGTMF) locations, geotechnical and hydrogeological testing validated highly competent rock with no significant alteration, no major structures, and low hydraulic conductivity,” the company said.

The mine plan at Arrow was based on conventional long-hole stoping using the 239.6 MIb of declared reserves, the company said.

“Geotechnical studies during the feasibility study re-emphasised the conventional long-hole stoping mining method, including the use of longitudinal and transverse stopes, 30 m level spacing, and the nominal stope strike length of 12 m to 24 m,” it said. “This represents an excellent stope stability range for underground mining in the highly competent conditions.”

Given the competency and conditions of the underground environment, all waste streams from the process plant are planned to be stored underground in the UGTMF, while process water streams will be treated on surface in the optimised effluent treatment plant, NexGen said.

The underground workings will be accessed by two shafts, with the production shaft supporting personnel movements, materials, ore, waste and fresh air. The production shaft was increased to 8 m in diameter (from 6.5 m in diameter in the prefeasibility study (PFS)) to optimise radiation and ventilation management, ensuring the mine is elite from a safety perspective, the company said.

“Additionally, the production shaft will have divided compartments, ensuring that fresh air and personnel entering the mine, remain isolated from ore being skipped to surface,” it added.

The exhaust shaft was ultimately decreased to 5.5 m in diameter (from 6.5 m in diameter in the PFS) and will be used for exhaust air and emergency secondary egress, NexGen said.

Like some other projects in the region, shaft freezing will be required to a point to secure the underground project, NexGen confirmed.

In terms of processing, NexGen said extensive test work and engineering had determined that proven technology in a conventional uranium processing flowsheet is most effective to produce uranium oxide from the Arrow deposit.

The main components of the processing plant are ore sorting; grinding; leaching; liquid-solid separation via counter current decantation and clarification; solvent extraction; gypsum precipitation and washing; yellowcake precipitation and washing; yellowcake drying; calcining and packaging; and tailings preparation and paste tailings plant.

Metallurgical testing resulted in supporting and refining process design parameters, with the process recovery of 97.6% confirming the predictable nature of the processing flow sheet, it said.

“The feasibility study also confirmed that all processed waste streams can be stored in the UGTMF and no surface tailings facility is required,” NexGen said. “The UGTMF is a reflection of NexGen’s industry-leading environmental design approach, contributing to the significant reduction of the project’s surface footprint, and representing an opportunity to implement best practice of progressive closure of tailings facilities during the operational phase of the mine.”

A feasibility study drill program validated the geotechnical conditions and favourable conditions for the UGTMF, with the study also optimising the geotechnical design, size and sequencing of the UGTMF included in the mine plan.

The study test work demonstrated paste fill strength met or exceeded all requirements set in the feasibility study design for a potential paste-backfill to be used for underground stope stability.

In terms of the timeline to production, NexGen said it planned to submit its Environmental Impact Statement in the second half of this year, along with relevant licences.