Processing alternatives could lift cobalt supply: CI

New approaches to refining mineral deposits could increase cobalt output as the market looks to diversify supply away from the Democratic Republic of Congo (DRC), delegates heard at the Cobalt Institute conference in Hong Kong.

Production in the DRC reached 125,000t of cobalt contained last year, accounting for around 70pc of global output. That share is set to rise further, as output is expected to increase to 200,000t of cobalt contained by 2025 with the start of new projects, said coordinator of the technical coordination and mining planning unit at the DRC mining ministry Paul Mabolia.

The DRC exports cobalt in the form of hydroxides, cobalt-copper concentrates and cobalt concentrates, white alloys, and cobalt carbonate. DRC cobalt hydroxide production increased to 350,000t in 2018, overtaking production of cobalt concentrate in response to demand from China for material to refine into battery chemicals, Mabolia said.

New approaches to processing copper and nickel could increase cobalt recovery from mines, said Richard Herrington, project leader with the COG3 consortium, which is developing bioprocessing strategies for cobalt extraction.

"There's a lot of under-evaluated cobalt," Herrington said. "A lot of sulphides have the potential to recover cobalt."

There are sediment-hosted copper deposits around the world, but only the Central African Copperbelt produces cobalt in large volumes. The Kupferschiefer copper deposit in Poland has more cobalt-rich parts of the ore body containing 120 parts per million (ppm) where cobalt is not being extracted, Herrington said.

Lateritic nickel-cobalt deposits account for around 20pc of cobalt production, but the focus on recovering nickel can neglect areas in the deposits where the most cobalt resides and the processing methods can lose cobalt that is not extracted. Cobalt is lost in pyrite waste in nickel-copper deposits, and is never recovered from ferro-nickel, Herrington said.

Unconventional deposits offer the potential to develop new mines, including a 763,000t cobalt resource in Cameroon in a limonite iron ore deposit and marine nodules containing cobalt.

"The biggest challenge may be getting new technologies to market fast enough to meet demand," Herrington said.

Development of deep-sea mining could extract the cobalt from polymetallic nodules and crusts, Tom Albanese, an adviser at mining exploration consortium CIC, said.

An estimated 120mn t of cobalt resources have been identified in the Atlantic, Pacific and Indian oceans, according to the US Geological Survey. Several methods for lifting the nodules from the seabed are being trialled in the Pacific Ocean. The nodules could be processed in the same way as nickel, Albanese said.

Each mining vessel could produce 4,000-8,000 t/yr of cobalt. The first vessels could go out in 5-10 years, a similar time scale to the development of land-based projects, Albanese said. "That takes us to 2025, 2030… meeting this big gap between cobalt supply and demand at the right time."

Cobalt demand for passenger electric vehicles could reach 50,000-75,000t by 2025 depending on the dominant battery chemistry, said principal nickel and cobalt analyst at producer Norilsk Nickel Alex Khodov.