Cobalt Blue (ASX:COB) reports it has completed a first phase of test work focusing on gravity separation of cobalt-pyrite from the ore at the Broken Hill Cobalt Project, located in New South Wales.
The ore was milled from 4mm top size to a target of 1.5mm top size using a roller mill. This simulated the use of a High Pressure Grinding Roll (HPGR) mill in the circuit.
In the initial program, a total of 500 tonnes of ore has been processed to produce 125t of concentrate.
The average grade of gravity circuit concentrate was 4,360ppm cobalt across the first phase of test work, and a mass rejection of 75% to tailings.
In phase two of the test work program, a ball mill will be used to prepare finer feed material to the circuit (target p80 600um to 800um).
Additionally, a float circuit will be used to recover the fine fractions of pyrite (under 75um). Overall target recoveries of over 90% are expected with these inclusions. These recoveries and upgrades are in line with Cobalt’s earlier technical studies.
The treatment of cobalt-pyrite involves 2 key steps, the first is converting pyrite into pyrrhotite and elemental sulphur, followed by leaching of the pyrrhotite.
The solubilised cobalt is then recovered by precipitation as a mixed hydroxide with grades of 30% cobalt and 7% nickel.
The Demonstration Plant kiln was successfully commissioned in September, with the first 5t of concentrate being processed.
Feed rates to the kiln are 150-200kg/hr, and further work is ongoing to improve off-gas handling of recovery of the sulphur.
The next unit block for operations are the leach and Mixed Hydroxide Precipitate (MHP) production circuits during October.
The approximate 5x grade improvement from concentration is a key project enabler, with phase one of this large-scale work continuing to confirm expectations
Cobalt Blue CEO Joe Kaderavek said the approximate 5x grade improvement from concentration is a key project enabler, with phase one of this large-scale work continuing to confirm expectations.
Cobalt Blue is a mining and mineral processing company focused on the development of the Broken Hill Cobalt Project in New South Wales.
The portfolio of 4 granted tenements in a total area of 63km-square containing ‘large tonnage’ cobalt-bearing-pyrite deposits are located 23km west of Broken Hill and 400km by rail to Port Pirie.
Cobalt Blue has developed a patented minerals processing technology for treating pyrite feedstocks targeting 85 to 90% recovery of cobalt from ore to product (as Mixed Hydroxide Precipitate or Cobalt Sulphate).
The Broken Hill Cobalt Project has a targeted project life of over 20 years and will be a ‘significant’ employer in Regional NSW with around 400 full-time jobs generated.
The company will become a global top 10 producer of cobalt, a key critical mineral with strong demand growth from lithium-ion batteries widely used in electric vehicles and energy storage systems.
The expected timeline for the Broken Hill Copper Project is subject to various risks, some of which are outside the control of the company and which include successful and timely completion of project milestones, funding availability, government and other third-party approvals.