Revving up

Upgrading a decades-old site to turn it into North America’s first cobalt refinery

Published in CIM Magazine, March/April 2021 issue. Reprinted with permission of the Canadian Institute of Mining, Metallurgy and Petroleum (

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.

Technical considerations

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.”