Canada Nickel identifies new method for accelerated CO2 capture

The laboratory scale test programme demonstrates that this accelerated carbon capture process could allow Crawford tailings to absorb enough carbon dioxide (CO₂) to achieve net zero carbon emissions within 36 hours, and generate up to 21 t of CO₂ credits per tonne of nickel produced within just six days, rather than the multiple months involved in existing passive tailings approaches. At Canada Nickel’s Crawford Project, this translates into an average of approximately 710 000 tpy of CO₂ credits and 18 million total t of CO₂ credits over the preliminary economic assessment (PEA) life-of-mine.

Mark Selby, Chair and CEO of Canada Nickel, commented: “These laboratory scale test results demonstrate a potentially transformative process to turn a nickel mine into a net generator of carbon credits rather than a generator of carbon emissions. Our active and accelerated process has the potential to operate at least 8 – 12 times faster than current passive approaches, delivering carbon capture at a multiple of what industry leaders are currently able to achieve. Our process also allows easier quantification and verification of the amount of carbon captured.”

Canada Nickel’s Crawford Project is hosted in ultramafic rock, which naturally absorbs and sequesters CO₂. The potential to actively capture and sequester carbon was a key consideration in Canada Nickel’s acquisition of the 42 km² of target ultramafic rocks in the Timmins area which could anchor a zero-carbon industrial cluster near Timmins. The challenge has been to develop a process that speeds up the naturally occurring carbon absorption process. Canada Nickel has developed a simple active process that utilises tailings as generated in the milling process and injects a concentrated source of CO₂ for a brief period of time. This novel process for accelerated mineral carbonation is called IPT Carbonation, which fixes CO₂ geologically while the tailings are still in the processing circuit, rather than after they have been finally deposited.

While Canada Nickel’s IPT Carbonation process has only been demonstrated on a laboratory scale and on a limited number of samples, the company believes that, given its relative simplicity, this process could be scaled up with availability of concentrated (rather than atmospheric) sources of CO₂. This CO₂ could potentially be delivered by downstream processing of Crawford concentrates, a wide range of industrial processing activities, green hydrogen production, carbon capture facilities, or natural gas power generation. The process clearly demonstrates the potential to produce NetZero Nickel^TM and NetZero Cobalt^TM for the EV industry, NetZero Iron^TM and chromium for the stainless steel industry and generate substantial carbon credits during the process. The company believes that the need for a concentrated source of CO2 for this process and the substantial CO₂ capture capacity potential of its ultramafic land position could form the basis for an entire zero carbon industrial cluster in the Timmins region.

IPT Carbonation

The IPT Carbonation process utilises tailings directly from the mineral processing circuit and conditions them with CO₂ for a brief period of time. After this conditioning, the tailings achieved the net zero carbon capture target in less than 36 hours and achieved gross carbon capture rates of at least 26 t of CO₂/tonne of nickel (five times the amount necessary to achieve net zero metal production) in just six days. During this time, the rate of capture was 8 – 12 times faster than a laboratory scale passive approach. Both samples tested with IPT Carbonation have achieved or surpassed the complete theoretical carbonation of the ultramafic mineral brucite, which is significant as the capacity of brucite to sequester carbon, at Crawford alone, is estimated to be more than 13 million t of CO₂ over the estimated life of the project. The experimental method and results for IPT Carbonation were initially completed at XPS, Expert Process Solutions, a Glencore Company, and the mechanism was then reproduced at a second independent lab, Kingston Process Metallurgy, adding confidence to the process. No further information is being provided on the method at this time and work is underway to test a wide range of variables to optimise the process.

Based on mineralogy data captured in the Crawford PEA, the average brucite concentration of samples characterised in the resource was 2%. These initial laboratory scale results suggest that carbon capture beyond the theoretical maximum in brucite is possible. Canada Nickel is working towards incorporating the brucite content into the block model as an estimate for the total carbon capture potential of the project in the feasibility study.

Validation and measurement of CO₂ credits

IPT Carbonation, which is an active process, has benefits over passive mineral carbon capture as the method for quantifying and verifying CO₂ capture is expected to be much simpler. Using a standard carbon balance in the mineral processing facility, the CO₂ captured from IPT Carbonation can be quantified before tailings are discharged into the permanent tailings storage facility such that carbon offsets can be quantified in real time as part of a standard metallurgical accounting system. Canada Nickel expects industry standards to be developed for quantifying CO2capture through passive methods as well.

Read the article online at: https://www.globalminingreview.com/environment-sustainability/22072022/canada-nickel-identifies-new-method-for-accelerated-co2-capture/