Cobalt Blue Holdings Ltd’s (ASX:COB) (OTCMKTS:CBBHF) tests on ore from the Broken Hill Cobalt Project (BHCP) have achieved a series of product benchmarks for cobalt sulphate, elemental sulphur and mixed hydroxide precipitate, which will be used for offtake marketing purposes with commercial customers.
The test program has produced 20.8% cobalt sulphate suitable for the lithium-ion battery market with the added benefit to BHCP economics of 99% grade sulphur.
After demonstrating the production of high-purity cobalt and sulphur products, the company is now finalising a 2020 project update and ore reserve statement for the project.
Results expected to improve economics
COB expects the test results will further improve the BHCP economics delivered as part of the 2018 pre-feasibility study.
Chairman Rob Biancardi said: “We are excited to announce these premium cobalt and sulphur product results.
"Our extensive test-work demonstrates that the BHCP can produce high-purity, battery-ready cobalt sulphate that will power the electric vehicles of the future.”
Prilled Elemental Sulphur produced in the tests (on a 5x5mm grid).
The recent test-work results confirm that high-purity products can be achieved using the process for recovery of metals from pyrite.
Starting with drill samples from BHCP deposits, a series of test-work programs has been completed culminating in the production of cobalt sulphate, elemental sulphur and mixed hydroxide product (MHP) samples.
The production of these final refined product samples will now be followed by pilot-scale trials in the purpose-built pilot plant at Broken Hill.
COB will use the product samples in discussion with strategic partners – as per the cobalt products program (Cobalt Product and Sulphur Sample Program) and the sulphur product assessment agreement with Mitsubishi Corporation (COB–Mitsubishi Corporation Sulphur Agreement).
Samples of cobalt sulphate will also be provided to the Australian Future Batteries Industries – Co-operative Research Centre for processing into cathode precursor, along with other Australian sourced raw material – nickel sulphate (NiWest, IGO), lithium hydroxide (Tianqi Lithium Australia), and manganese sulphate (Pilbara Metals Group).
Cobalt Blue said earlier MHP test-work produced a 37% cobalt and 7% nickel premium MHP with low impurities.
A 20.8% cobalt sulphate heptahydrate has been produced by refining the MHP.
This meets the industry benchmark of 20.5% purity for battery manufacture. The key by-product for BHCP is elemental sulphur and the company has now produced 99.3% grade elemental sulphur samples.
Large-scale furnace work
In addition, BHCP sample concentrate (7.5 tonnes) is being stored at ANSAC (ANERGY) in Bunbury WA in preparation for calcine (furnace) test-work.
After thermal decomposition, this calcined material will be moved to the pilot plant at Broken Hill.
The calcined material will be used for leaching and metal recovery trials, whilst providing approximately 1 tonne of elemental sulphur for assessment by Mitsubishi Corporation.
Availability of personnel to run these trials has been affected because of business responses related to the COVID-19 pandemic, however, the company said the sample would be available in time for pilot plant commissioning later in the year and the test-work to be conducted over the current quarter.
Pilot plant update
The proposed metallurgical testing centre in Broken Hill will scale from an initial pilot plant operation producing between 100-300 kilograms of cobalt sulphate from 90 tonnes of ore, to a larger scale fully integrated demonstration plant producing 1-2 tonnes of cobalt sulphate using up to 2,000 tonnes of ore.
These results will form the evidentiary basis for the engineering designs and cost estimates for the BHCP feasibility study.
The company also said that equipment for the pilot plant had arrived on-site in Broken Hill and was in the process of being installed.