Published in CIM Magazine, March/April 2021 issue. Reprinted with permission of the Canadian Institute of Mining, Metallurgy and Petroleum (www.cim.org)
Cobalt, Ontario, earned its place in Canadian mining history as the site of an early 20th-century silver-mining rush that made it the largest producer of the metal in the world. Now, the former mining town will soon play a role in what has the potential to be another rush when it becomes a key part of the electric vehicle (EV) production chain.
Toronto-based First Cobalt is set to bring North America’s only primary cobalt refinery, a decades-old site site that has been on care and maintenance since 2015, into production October 2022. It comes as the EV market is rapidly growing: according to the International Energy Agency, electric vehicle stock is expected to increase by 36 per cent annually, to more than 245 million vehicles on the road in 2030. The cobalt content in the batteries that power the cars, trucks and SUVs is projected to increase from 5.5 kilograms per EV in 2017 to 11 kilograms per EV by 2030, according to a 2018 report by the European Commission’s Joint Research Centre.
At the moment, China is the largest producer of cobalt sulfate, the bright pink soluble compound that is used to produce the cobalt and mixed-metal cathodes that end up in lithium ion and lithium polymer batteries. The country now accounts for 79 per cent of the world’s refined cobalt sulfate production, a number that’s expected to increase further, according to Benchmark Mineral Intelligence. The firm found that there are no plans to commission new cobalt refineries outside of China – with the exception of First Cobalt’s.
First Cobalt’s president and CEO Trent Mell said the refinery’s location will give the company a leg up with domestic EV producers, and even those in Europe and Japan. “As the battery industry matures here, the on-continent appeal of our refinery gets bigger and bigger,” he said.
When the hydrometallurgical refinery becomes operational, it will have a nameplate throughput capacity of 50 tonnes of cobalt hydroxide feed per day, working out to 5,000 tonnes of cobalt – or 25,000 tonnes of battery-grade cobalt sulfate — produced annually. The plant’s output would represent five per cent of today’s global refined sulfate output. That production should come with a smaller environmental footprint than its Chinese competitors, producing only 1.58 kilograms of carbon dioxide (CO2) equivalent per kilogram of cobalt, in comparison to 3.25 kg of CO2 equivalent at a benchmark refinery in Tongxiang, China, which Mell said comes down to the refinery’s access to Ontario’s hydroelectric power grid.
To prepare for the operation’s restart, First Cobalt needed to significantly upgrade the refinery’s throughput and equipment, and revamp its refining processes.
When fully operational, First Cobalt is expected to process 55 tonnes per day of cobalt hydroxide.
Building on history
The site was first developed in the 1980s, initially as a mill that produced silver and cobalt, and from 1996 onward as a refinery with a permitted throughput of 12 tonnes per day (t/d). In the decades before First Cobalt acquired the site in 2017, a series of owners tried, and failed, to profitably run the operation, often struggling with a lack of consistent feed or the poor economics of a small-throughput refinery.
Working with a brownfield site gave the company some built-in advantages, Mell said. The site was already permitted, cutting out a lengthy step in the process (though First Cobalt did need to file permit amendments to increase the footprint of the site in line with the new throughput capacity). The company also benefitted from previous owners’ investments, which it estimated at around US$85 million. That included site infrastructure – power lines, roads, electrical equipment and the complex itself – as well as good-quality equipment, including a pressure oxidation circuit, solvent extraction (SX) circuit and product filtration, as well as a laboratory and other buildings.
But some of the equipment that was designed for a manual, low-throughput operation also presented a challenge. “You have a lot of redundant equipment that is just too small for what we had anticipated,” Mell said. “So, you’re going to be ripping stuff out, putting some bigger tanks and SX equipment in there – what that means is [when] you start playing with a brownfield, it’s kind of hard to anticipate the cost structure.”
First Cobalt hired Ausenco Engineering Canada in 2019 to build a business case for restarting the refinery. While an early scoping study and metallurgical test work identified cobalt hydroxide – which is mined directly and represents 70 per cent of the world’s cobalt supply – as the ideal feed material for the refinery, Ausenco’s pre-feasibility study looked at another source of cobalt. It envisioned restarting the refinery in 2020 under the existing 12 t/d throughput, processing white metal alloy – an intermediate product of cobalt smelting – as an interim feed source and then ramping up to the higher throughput of cobalt hydroxide in 2021. First Cobalt and Ausenco discarded that plan: while it would get the refinery operating sooner, it would have involved refurbishing or installing equipment that worked only at the lower throughput, and then replacing it later.
Instead, in the feasibility study, Ausenco looked at what process engineer Thomas Mills called the “main prize” of a significantly expanded plant and full refinery upgrade to allow First Cobalt to immediately begin processing 55 t/d of cobalt hydroxide.
“We’re using the existing infrastructure but actually little of the existing equipment can be used,” Mills said. “New equipment and new buildings are being added, [there’s a] significantly new refining process, with an expansion to the existing tailings capacity.”
The ultimately approved feasibility study estimated an initial capital cost of $60 million and an operating cost of $2.36 per pound of cobalt produced. It also prompted First Cobalt to reconsider its business plan and sell its cobalt sulfate directly to EV manufacturers. The company’s initial plan was to toll treat feed for Glencore, under an agreement that would see the major miner finance most of the refinery’s upgrade. But the feasibility study’s conclusions coincided with an upswing in the cobalt market, which made the company “more confident in our ability to fund the refinery capital costs ourselves,” Mell said.
In January 2021, the company announced it had secured cobalt hydroxide supply agreements with Glencore’s Kamoto Copper Company mine and CMOC’s Tenke Fungurume mine in the Democratic Republic of the Congo totalling 4,500 tonnes per year of contained cobalt, representing 90 per cent of the refinery’s projected capacity. Mell said the company may opt to source the remaining 10 per cent on the spot market.
Ausenco and First Cobalt had to consider numerous factors when developing the refinery’s new flowsheet and site design, including the impurities likely to be present in the feed, battery manufacturing specifications for cobalt content and more. But perhaps the most significant was existing environmental and effluent regulations, Mills said.
Those considerations led the company to approve the construction of a filtered tailings facility with a 17-year capacity, instead of a conventional wet tailings facility. Filtered tailings are more stable and at less risk of failure than conventional wet tailings, said Mills, noting that the facility can also be quickly reclaimed. In addition, an effluent treatment plant will treat any process water and return it to the nearby Lake Temiskaming. “The effluent treatment plant is designed to remove impurities to meet environmental standards prior to discharge,” he explained.
While the feasibility study involves nearly quintupling the throughput capacity, Mell said the site footprint will only double. In addition to the filtered tailings facility, the company will add to an expanded solvent extraction circuit and a large crystallizer circuit to the site.
When the refinery is operational, cobalt hydroxide will travel through a feed preparation stage, before being leached in sulfuric acid under atmospheric conditions. The neutralization circuit and two solvent extraction circuits will remove any iron, gypsum, manganese, copper, zinc, iron, calcium, nickel and magnesium from the cobalt material. The crystallizer – the last stage in the process – uses steam to evaporate water in a heat exchanger to crystallize the cobalt, before sending the material on to a thickener and centrifuge for further dewatering, and a fluid bed dryer to cut the moisture con- tent to below 0.2 per cent weight per weight.
The final product will be a cobalt sulfate heptahydrate, which complies with the toughest EV manufacturing specifications and, as a fully hydrated compound, faces less risk of absorbing water and clumping up during transport, Mell said.
Closing the loop
With $16 million in working capital and a $10 million investment from the Canadian and Ontario governments, First Cobalt announced in January it was beginning six months of pre-construction activities, which includes detailed engineering, purchasing some of its longest-lead items, including the crystallizer and solvent extraction and filtering equipment, and reviewing the refinery flowsheet for any potential improvements. First Cobalt continued its relationship with Ausenco, contracting the company for engineering, procurement, construction and management.
Looking to the future, First Cobalt is eyeing black mass material from recycled batteries as an additional cobalt feed source. In comparison to the pyrometallurgical approach of roasting the batteries, the hydrometallurgy (or hydromet) facility would instead dissolve the material and extract the metals. Mell said the company expects it could recover nickel, copper and cobalt, and potentially lithium and manganese through that process.
Building a facility from the ground up to refine black mass could cost hundreds of millions of dollars, but First Cobalt would face only incremental costs to process the additional feed sources. “The way we considered it was, how do we start with [cobalt] hydroxide and allow ourselves the opportunity and flexibility to process additional feed sources in the future,” Mills said. “It can be achieved quite readily. Generally, we would need to add on a nickel recovery system, including additional solvent extraction stages and another crystallizer.”
Battery recycling is a growing conversation in the EV space, particularly as the first generation of vehicles start to reach the end of their lifespan.
“[For us] it’s a natural evolution, and it strengthens our ESG [environmental, social and governance] mandate. It then provides us with a non-DRC domestic supply of feedstock, we’re part of the closed-loop supply chain,” Mell said, adding that “even though it’s in phase two, the OEMs [original equipment manufacturers] have taken a keen interest in our ability to process black mass because it helps their carbon footprint as well.”