ASX-listed base and precious metals miner West Wits Mining has updated the mineral resource estimate for its Witwatersrand Basin Project (WBP) to 4.28-million ounces of gold, at an average grade of 4.58 g/t gold.

The new mineral resource estimate includes measured, indicated and inferred resources.

Further, an updated scoping study has determined that the mine has a life of 27 years with an estimated 16.1-million tonnes at a run-of-mine grade of 3.11 g/t gold for 1.61-million ounces from mining stages 1 to 42.

The new scoping study also points to the WBP having an all-inclusive sustaining cost (AISC) of $1 138/oz for production above 800 m – 72% of total production, increasing to $1 198/oz, including Stage 4 Qala Deeps, for production deeper than 800 m.

In addition, the new scoping study finds the WBP mine will have free cashflow of $511-million, a net present value before tax of $227-million and post-tax of $160-million, as well as a pre-tax internal rate of return of 33%  and post-tax of 29%.

The first stage of development of the WBP, Qala Shallows, has an ore reserve of three-million tonnes at a grade of 2.88 g/t for 278 000 oz, which includes a proved ore reserve of 830 000 t at a grade of 3.13 g/t for 84 000 oz.

The Qala Shallows stage of development has a 17-year life-of-mine for 7.3-million tonnes at a grade of 2.81 g/t for 663 000 oz. This stage also has an AISC of an estimated $1 144/oz of gold with steady-state costs of $1 027/oz.

With West Wits having started its early mining initiative at Qala Shallows, the miner aims to produce between 5 000 t and 8 500 t a month from April.

Meanwhile, West Wits started its Bird Reef Central Uranium exploration programme, which forms part of the WBP, in the second half of 2021, aimed at converting the significant uranium exploration target to a Joint Ore Reserves Committee- (Jorc-) compliant mineral resource estimate.

The Bird Reef project is set to be undertaken to target uranium in the fourth stage of the WBP development.

The Bird Reef already has a declared Jorc-compliant gold mineral resources estimate of 4.67-million tonnes at a grade of 3.13 g/t for 469 400 oz of gold.

The next phase of work on the Bird Reef target involves exploration activities designed to test the validity of the newly defined exploration target, with the programme intended to extend exploration to the east of the Bird Reef sequence, which did not form part of the 2008 exploration programme and remains unexplored to date.

AUSTRALIA
Meanwhile, exploration at West Wits’s Western Australia-based Mt Cecelia project, using moving-loop time-domain electromagnetics (MLTEM) in the second half of 2021, provided the miner with robust first-pass exploration drill targets, which it anticipates to start exploring further this year.

As such, 16 lines of MLTEM data were acquired at four target prospect areas.

Of these, and as a result of a helicopter-borne electromagnetic survey, target SGC_1 was classed the highest priority target as a result of the clearly discrete nature of the anomalism and correlation with a zone of de-magnetisation in the local sequence.

In December 2021, West Wits entered a farm-in and joint venture (JV) agreement with wholly-owned subsidiary of Rio Tinto, Rio Tinto Exploration (RTX) to explore the Mt Cecelia prospect.

RTX brings a wealth of technical expertise, resources and regional knowledge which, combined with synergies from their exploration of Mt Cecelia’s neighbouring tenements (that are held 100% by RTX), will enable the Mt Cecelia targets to be rapidly and systematically tested.

In stage 1 of the JV, RTX will pay West Wits $150 000 in cash to attain a sole and exclusive right to earn an initial 51% JV interest in the tenement by sole funding exploration expenditure of A$4-million within four years after the agreement’s execution date.

This involves a minimum of 800 m of diamond core and/or reverse circulation drilling on the tenement before the end of this year.

Once RTX has earned a 51% interest in the tenement, the JV will be made official, following which RTX has the right to solely fund a further A$6-million in exploration within three years of the JV formation date to earn an additional 29% interest – 80% total RTX interest.

If RTX makes the Stage 2 sole fund election, RTX must pay West Wits a further $250 000.