From link above
Wiluna: Lake Way, Centipede & Millipede, WAmce-anchorLake Way, Centipede and Millipede comprise the core of Toro Energy's
Wiluna Uranium Project. However, Toro’s acquisition of Lake Maitland in 2013 enabled a complete revision of development strategy, due to significant increase in grade at the plant. For the first ten years the average head grade increases from 0.072% to 0.088%, and production of 900 t/yr U
3O
8. The total resource base in February 2016 was 38,000 tonnes at 0.048% U
3O
8 with 200 ppm cut-off. Of this, 18,000 tonnes at Centipede, Millipede, Lake Maitland and Lake Way is measured and indicated resources with average grade of 0.0951% U
3O
8 and 500 ppm cut-off. With 200 ppm cut-off there is 27,400 tonnes U
3O
8 measured & indicated resources in these deposits at lower grade, about 0.053%.
In May 2016 Toro announced results from beneficiation test work on Lake Maitland ore, but relevant also to Centipede, Millipede and Lake Way. Using screens and cyclones to reject 80% of the mass with 90% recovery, ore at 0.22% was beneficiated to 0.997% U
3O
8. The samples concerned represented about 60% of Lake Maitland ore. Toro has also tested Marenica’s U-pgrade beneficiation technology which has been effective on carnotite in Namibian deposits, but has adopted a different beneficiation method, delivering a 75% mass reduction with 84% uranium recovery. In March 2019 Toro announced that uranium recovery in the test plant was almost 83% and operating costs for the beneficiation and processing plant were A$ 14.59/lb.
The Lake Way deposit, close to Wiluna, 750 kilometres northeast of Perth in Western Australia, was discovered in 1972.*
* Delhi International Oil Corporation (53.5%) and Vam Ltd (46.5%) were joint venturers initially, but Asarco Australia Ltd bought out its partner and in 1994 became Wiluna Mines Ltd, whose main focus is on gold. Acclaim Uranium held the deposits in the 1990s but Nova Energy Ltd had them by 2006, and then merged with Toro Energy. In 2011 Toro purchased the uranium rights in the Millipede tenements, adjacent to Centipede, for $4.5 million.
Lake Way is a very shallow low-grade carnotite deposit in calcrete and clays. It averages 1.5 metres thick but ranges up to 5 metres below the surface. It was to have been mined by four or more pits over some 9 square kilometres, but plans were abandoned in 1983. The Centipede calcrete deposit is 12 km south of the Lake Way deposit. It consists of two or three lenses of 1 to 5 metre thick mineralisation containing carnotite through the carbonate matrix of a chemical delta where a 30 km drainage system enters Lake Way. Millipede is similar, and connected to Centipede.
Toro Energy undertook feasibility studies for shallow low-cost open cut mining of these three deposits. The ore requires a carbonate high-temperature leach plant, at about 92ºC, alkaline heap leach having been tried and rejected. Recovery of 86% has been demonstrated in the pilot plant. In November 2013 Toro reported JORC-compliant measured and indicated resources of 13,900 tonnes U
3O
8 at 0.055% average with 200 ppm cut-off for the three deposits, 40% of this in Lake Way. It holds mining leases for Centipede and Lake Way, and awaits one for Millipede.
The Dawson-Hinkler Well deposit near Wiluna has a JORC-compliant indicated resource of 2800 tonnes U
3O
8 with average grade 0.037% U
3O
8, at 200 ppm cut-off, plus some inferred resources. The deposit is in the same palaeochannel as Centipede and Millipede deposits 20 km east. The deposit occurs over 15 km strike length, and selective mining was planned with 1:1 waste to ore strip ratio. In 2010 Toro Energy bought the deposit for A$ 6.2 million, thereby increasing its Wiluna resources by one quarter to 13,800 t.
Nowthanna is south of Meekatharra and has 5400 tonnes U
3O
8 at 0.04% inferred resource, but with a core of 0.08% material which could be economic to truck 150 km to the Wiluna treatment plant. It was purchased by Toro for $2 million in 2011-12.
In November 2009 Toro acquired the Firestrike tenements, 20 km SE of Centipede. No resource figures have been published.
Toro’s total regional resources for six deposits including Dawson-Hinkler, Nowthanna and Lake Maitland (see below) in November 2015 were 29,300 t U
3O
8 measured and indicated resources grading 0.053%, including a high-grade portion of 16,860 tonnes at 0.92% (with 0.05% cut-off). Including inferred resources, the project total in October 2015 comes to 36,600 t U
3O
8 grading 0.0485%. Lake Maitland has made the Wiluna project a higher-grade and longer-life prospect.
Toro undertook a bankable feasibility study, and in October 2012 the state government gave final environmental approval to the Centipede-Lake Way part of the project. In February 2014 Toro applied for environmental approval for mining Millipede and Lake Maitland, using the planned processing plant at Centipede. An environmental scoping document on this was approved in February 2015. In September 2016 the state EPA recommended expanding the earlier approval to incorporate Millipede and Lake Maitland, with a haul road from Lake Maitland, enabling the four orebodies to be developed coherently. The state government approved this in January 2017. Federal government environmental approval covering the four deposits and related infrastructure including a haul road from Lake Maitland was granted in July 2017.
The priority will be mining the high-grade parts of the deposits, giving a feed grade of 0.088% U
3O
8. Centipede-Millipede will be mined first, then Lake Maitland, then Lake Way. Production of 900 t/yr U
3O
8 (770 tU/yr) over some 16 years is planned. Project cost is put at $316 million, and operating costs US$ 31/lb. Subsequently the actual plant cost including vanadium recovery was put at AUD 94 million, with operating cost AUD $11.67/lb. In July 2016 a mining agreement with the Aboriginal traditional owners was signed.
Environmental approval will later be sought for Dawson-Hinkler and Nowthanna. Later Firestrike and Albion Downs will come into the picture.
The Wiluna project is stalled pending improvement in uranium prices. In October 2019 Toro declared a JORC-compliant maiden resource of 68.3 million pounds (31,000 t) of vanadium pentoxide for the project, likely to help its feasibility. A study completed in 2021 confirmed that vanadium could be an economic byproduct from the three main uranium deposits, with potential production of 500 t ammonium metavanadate along with 950 t U
3O
8 per year.
Lake Maitland, WASeveral shallow calcrete deposits are under agreement to be acquired by Toro Energy at Lake Maitland, 90 km SE of the Wiluna project. Carpentaria Exploration, Esso and then Acclaim Uranium evaluated these in the late 1990s. In 2006
Mega Uranium Ltd acquired Redport Ltd, which then held the deposit. In February 2009 it agreed to sell a 35% share of the project to the Itochu Corporation (10% of Japanese share) and Japan Australia Uranium Resources Development Co. Ltd. (JAURD), acting on behalf of Kansai Electric Power Company (50%), Kyushu Electric Power Company (25%) and Shikoku Electric Power Company (15%) for US$ 39 million.
In 2013 Toro Energy bought the project for $37 million in shares, which gave Mega a 28% share of Toro. (Toro’s subsidiary Nova acquired Mega’s subsidiary Redport.)
The deposit underlies the northern end of Lake Maitland itself. The mineralised zone is about 6 km long and 300-600 m wide, 1.5-2.0 m below the surface and average 1.7 m thick. Mine depth will average 4 metres. In 2013 Toro confirmed a NI 43-101 compliant indicated resource of 11,000 tonnes U
3O
8 grading 0.0555%, at 200 ppm cut-off. In February 2016, 7680 tonnes of higher-grade material at 0.0929% (500 ppm cut-off) was confirmed, which can be blended with Wiluna ore. The ore is very similar to that at Wiluna. Beneficiation trials show an upgrading to 1% compared with feed grade of 0.2% from the main ore type.
In September 2009 Mega was awarded a mining lease, and a definitive feasibility study was under way for a 750 t/yr operation. Toro’s immediate focus is to improve the geological understanding of the deposit, integrate it into the broader Wiluna Project mine scheduling and design work, optimise mine planning, and progress environmental approvals. See also paragraph on beneficiation above, under
Wiluna.
Theseus – Lake Mackay, WAThe Theseus prospect is part of Toro Energy's Lake Mackay Project, located 650 kilometres west of Alice Springs but inside the WA border. Toro is evaluating two palaeochannel mineralisation models with PFN tool: a Kazakhstan style 'tabular model' and a Beverley style 'roll front model', both of which could be amenable to ISL mining at 100-125m depth. There are positive intersections and resource figures are expected in 2012, with 'exploration target' of 10,000 to 20,000 tonnes U
3O
8 at 0.04 to 0.05%. Good grades extend over several kilometres. Toro expects to boost Wiluna production from Theseus as an early stage operation.