The operation is planned as large-scale and aims to be one of the largest cobalt producers in the world. In fact, if Broken Hill were a country, if we hit our production target, it would rank number 5 for cobalt production.
The operation is intended to be low-cost. Our process separates over 80% of the waste from the ore at the first step. This means we intend to refine less than 20% of the material brought out of the ground. The refinery then processes a 0.5% cobalt content concentrate.
The operation is well-serviced. The mine can have a direct connection to rail transport, power, and water.
The Broken Hill Cobalt Project is located approx. 25 km southwest of Broken Hill, in far western New South Wales. The Project covers an area of roughly 37km² within a broader tenement holding of almost 220km².
The Broken Hill Cobalt Project is located in a deformed and metamorphosed Proterozoic supracrustal rock succession named the ‘Willyama Supergroup’, which was deposited between ~1720 and ~1640 million years ago. It hosts most metalliferous occurrences, including the giant Broken Hill Pb-Zn-Ag (lead, zinc, silver) orebody.
The deposits are characterised by moderate to steep dipping stratabound zones of disseminated to semi-massive cobaltiferous pyrite mineralisation. This forms 3 distinct bodies known as Pyrite Hill, Big Hill, and Railway.
The deposits extend over some 5 km of strike and vary in thickness from 10 to 300m. The cobalt occurs exclusively as a substitute within the pyrite crystal lattice, and consequently, there is a strong correlation between pyrite content and cobalt grade.
A unique mineralogical composition distinguishes the Broken Hill Cobalt Project deposits from the Nickel - Cobalt laterite, Nickel - Copper (Cobalt - PGE), and Copper - Cobalt sulphide deposits, which account for some 98% of global cobalt production.
The Broken Hill Cobalt Project hosts a global Mineral Resource estimate comprising 118 Mt at 859 ppm (parts per million) cobalt-equivalent (CoEq) (687 ppm cobalt, 7.6% sulphur & 133 ppm nickel) for 81.1 kt contained cobalt, (at a 275 ppm CoEq cut-off).¹
The Probable Ore Reserve of estimate for the deposits comprises 71.8 Mt at 710 ppm cobalt and 7.6% sulphur. The Ore Reserve estimate was based on, and inclusive of, the Mineral Resource estimate released 4 April 2019 now superseded by the Mineral Resource estimate released 16 September 2021.²
The Broken Hill Cobalt Project mine schedule also considers a production target comprising 98 Mt at 690 ppm cobalt and 7.4% sulphur for 67 kt of contained cobalt. The production target is inclusive of a small component (approximately 20%) of Inferred Mineral Resources captured by the final pit designs.³
¹ These estimates of mineral resources were reported in the announcement titled ‘BHCP Resource Update’ dated 16 September 2016. Cobalt Blue it is not aware of any new information or data that materially affects the information included in the relevant announcement, and that all material assumptions and technical parameters underpinning the estimates in the relevant announcement continue to apply and have not materially changed.
² These estimates of ore reserves were reported in the announcement titled ‘’Broken Hill Cobalt Project (BHCP) Project Update 2020’ dated 16 July 2020. Cobalt Blue it is not aware of any new information or data that materially affects the information included in the relevant announcement, and that all material assumptions and technical parameters underpinning the estimates in the relevant announcement continue to apply and have not materially changed.
³ The production target and financial information/estimates derived from it in this announcement were reported in the announcement titled ‘’Broken Hill Cobalt Project (BHCP) Project Update 2020’ dated 16 July 2020. All the material assumptions underpinning the production target, in the initial public report continue to apply and have not materially changed. There is a low level of geological confidence associated with inferred mineral resources and there is no certainty that further exploration work will result in the determination of indicated mineral resources or that the production target itself will be realised.
Historically, cobalt has been produced as a concentrate by-product (from either copper or nickel mines), or as a mixed hydroxide or sulphide intermediate. In both cases, the payable cobalt content is a fraction of the metal value.
The Broken Hill Cobalt Project is an integrated mine-refinery concept. The commercial strategy is to extract the maximum cobalt margin in a rapidly changing global market for cobalt. As demand for particular forms of cobalt wax and wane, so too will our production outcomes, which can produce a mixed hydroxide product (MHP) or cobalt sulphate (CoSO4).
Mine
The Broken Hill Cobalt Project considers a multi-open pit mining scenario that will extract ore using conventional drill and blast, load and haul, and dump processes. The operation is planned to use excavators and rigid body trucks along with a fleet of auxiliary equipment.
Up to 6.3 million tonnes of ore are expected to be hauled annually to a stockpile area proximal to the processing plant located centrally to the pits. Waste material will be hauled to the waste emplacements situated close to each pit.
The flowsheet has been successfully tested at Cobalt Blue’s pilot and demonstration plants at Broken Hill. The steps in the processing technology are individually commercially proven although not previously combined elsewhere. The process has been patented in Australia, Japan, Korea, China and Africa.
Ore is crushed to approx. 1 mm, and a pyrite concentrate is recovered using a combination of gravity and flotation unit operations.
The pyrrhotite is forwarded to a low-temperature, low-pressure autoclave for leaching. The leach residue is removed by filtration and further processed for sulphur recovery by remelting. The leach solutions are advanced through various minor metals removal steps (precipitation, ion exchange, and solvent extraction) to remove iron, copper, zinc, manganese. The cobalt and nickel are precipitated as a mixed-hydroxide (MHP) intermediate.
The MHP is then refined for production of high purity cobalt sulphate heptahydrate. The target recovery from ore to product for cobalt is 85–90%.
The pyrite concentrate is thermally treated under an inert atmosphere to produce artificial pyrrhotite (calcine) and elemental sulphur. The sulphur is condensed from the kiln off-gas and turned into solid prills.
A Pilot Plant was commissioned in Broken Hill in early 2021 to replicate the process to extract cobalt from pyrite. The focus has now shifted toward constructing and operating a larger-scale Demonstration Plant to optimise Cobalt Blue’s proprietary processing technology. The Demonstration Plant will deliver sufficient product to support qualification as a supplier to global battery makers.
Broken Hill is located at the edge of the National Electricity Market high voltage grid, which typically means high cost. However, the completion of the (AGL) Broken Hill Solar Farm has created a peak excess of power to the town and local environments. The solar farm is located just 5 km west of Broken Hill (along the same highway as the Broken Hill Cobalt Project future mining operations). In addition, the Silverton Wind Farm (25km NW of Broken Hill) further amplifies this excess.
The Broken Hill Cobalt Project is connected to Broken Hill, Adelaide, Sydney and Melbourne via major highways.
An airport in Broken Hill services daily scheduled flights to Adelaide, Sydney and Melbourne (via Mildura).
The Broken Hill to Port Pirie train line commenced construction in 1875. The rail gauge has been standardised and upgraded, is 407km long, and runs directly past the Thackaringa mine site.
The NSW Government has built a new 270km pipeline from the Murray River to secure a long-term water supply for Broken Hill and surrounding communities. The pipeline solution supplies homes and businesses with a reliable and high-quality water source.
Essential Water is the water utility in Broken Hill. They have a significant business driver to supply water for economic development within the region. Essential Water have confirmed that they can supply the water requirements of the Broken Hill Cobalt Project using a pipeline between Broken Hill and the site.
The Broken Hill Cobalt Project is seeking State Significant Development approval from the NSW Government and an Environmental Impact Statement (EIS) is currently being prepared. The NSW Government will regulate the site via a series of permits or licenses, such as:
Cobalt Blue has adopted an IWL approach to manage our bulk waste streams. IWLs minimise acid generation through careful engineering and management of the waste rock. The IWLs are also progressively rehabilitated to produce a long-term stable structure that mimics the surrounding landscape.
In the past, mining companies have typically managed waste streams in separate facilities, which have sometimes left legacy issues for future generations.
Several Aboriginal artifacts are present on the site, with the majority being closely associated with the creeks that traverse the landscape. Some of the Aboriginal artifacts will be impacted by the proposal, and Cobalt Blue looks forward to developing a Cultural Heritage Management Plan with representatives of the local Aboriginal people to manage these cultural resources appropriately. Further Aboriginal heritage survey and assessment will be undertaken during the preparation of the Environmental Impact Statement.
