Cobalt Blue Holdings Ltd (ASX:COB, OTC:CBBHF) shares have gained about 4% intra-day to 81 cents after commissioning and starting operations of the demonstration plant at its Broken Hill Cobalt Project (BHCP) in New South Wales.
The plant is aiming to treat a minimum of 3,000 t (tonnes) of ore (up to 4,000 t) and produce about 10 t of cobalt products (mixed hydroxide and/or cobalt sulphate).
Background
In 2021, COB successfully built and operated a smaller-scale pilot plant.
This facility has now been upgraded over the last six months to increase capacity and includes all processing unit operations to treat ore to produce MHP (mixed hydroxide precipitate - typically 30% cobalt and 5% nickel), followed by refining to cobalt sulphate.
COB chairman Rob Biancardi said: “24-hour operations will commence shortly across the entire Demonstration Plant.
“This reflects real progress by our technical team and will allow BHCP to ship large scale test samples during Q3, providing a strong backdrop to commercial discussions.”
Mine site – crushed ore stockpiles.
COB’s demonstration plant program forms a key basis for the Broken Hill Cobalt Project Definitive Feasibility Study.
Ore for the plant is being sourced from the Pyrite Hill deposit. A 60-metre long underground portal was developed to access the orebody. To date, 2,300 t of ore has been extracted.
The ore has been stage crushed, followed by dry milling in a roller mill to a top size of ~ 1 mm.
The fine ore is now being processed through the concentrator circuit. The concentrate circuit is comprised of rougher and cleaner gravity spirals, and a scavenger flotation cell.
Concentrator – in action.
COB’s target is to generate a minimum of 600 t of concentrate from 3,000 t of ore.
The pyrite concentrate will be treated using the COB patented flowsheet to recover cobalt and elemental sulphur. The flowsheet is shown in Figure 1.
Figure 1 – BHCP process diagram.
In addition to the milling and concentrator circuits, the demonstration plant contains:
- A kiln for thermal decomposition of pyrite into pyrrhotite and elemental sulphur;
- an autoclave circuit for leaching pyrrhotite;
- iron removal circuit;
- MHP circuit;
- Refining circuit to produce cobalt sulphate (ion-exchange, solvent extraction, crystallisation); and
- onsite production of oxygen for the leach, and nitrogen for the kiln.
Kiln – with scrubber.
The demonstration plant program is expected to operate in aggregate for 20 weeks on a 24/7 basis.
The program will be split into campaigns, to allow for analysis and optimisation of the plant performance.
Samples of MHP and cobalt sulphate will be provided to prospective offtake parties.
Demonstration plant control system.
The early supply of samples will assist with qualification into the battery manufacturing chain, ahead of future commercial operations at the BHCP.
Samples of cobalt sulphate will also be provided to the Australian Future Batteries Industry CRC Precursor Pilot Plant.
This pilot plant opened in Perth earlier this month and is a collaborative activity with 19 industry, research and Government participants.
COB aims to produce Australian NCM (nickel manganese cobalt oxide) precursor using BHCP cobalt sulphate as a raw material input.
BHCP development schedule.