Critical Elements Successfully Produces Battery Grade Lithium Hydroxide in Pilot Plant Testing

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MONTRÉAL, QC / ACCESSWIRE / May 17, 2022 / Critical Elements Lithium Corporation (TSX-V:CRE) (OTCQX:CRECF) (FSE:F12) ("Critical Elements" or the "Corporation") is pleased to announce the results from the Corporation's pilot plant program recently completed at the Metso Outotec Research Center, successfully converting spodumene concentrate from the Rose Project ("Rose") into battery grade lithium hydroxide using a thermal leaching process.

The pilot plant conversion process from spodumene concentrate to lithium hydroxide was further optimized and confirmed the previous strong results with extraction and conversion rates of 92 %. In addition, the pilot plant produced battery grade lithium hydroxide. A summary of impurity levels is provided below:

The two critical steps of the process to recover the lithium from spodumene are the conversion from alpha spodumene to beta spodumene where the piloting work achieved 98% conversion rate and the separation of the lithium hydroxide from the calcined spodumene by soda-leaching (98% efficiency) and conversion to lithium hydroxide (96% efficiency).

• Battery grade lithium hydroxide with a further improved quality profile
• High spodumene alpha/beta conversion / leaching / conversion rates of combined 92%
  • Efficiency for the calcination 98%
  • Efficiency for the soda-leaching 98%
  • Efficiency for the lithium hydroxide conversion 96%

PILOT PLANT WORK DETAILS

The pilot plant work program was conducted at Metso Outotec's Research Center in Finland:

• Test work campaign, related to Metso Outotec's lithium hydroxide production process, was carried out for Critical Elements Lithium Corporation at the Metso Outotec Research Center in Finland and Germany.
• Varying concentrate grades were tested during the test work campaign.
• Two different North American lime sources have been qualified and approved.
• Process parameters have been modified and adapted.
• Concentrate used for pilot plant testing was provided from sample taken from Critical Elements Rose and Rose South zones.
• During the test campaign, the process flowsheet was optimized.
• The main unit operations in the pilot process were:
  • Calcination of alpha spodumene
  • Slurry preparation for soda leach
  • Soda leach of calcined spodumene
  • Soda leach residue filtration and washing
  • Lithium hydroxide conversion by lime
  • Conversion residue filtration and washing
  • Solution purification by ion exchange
  • Lithium hydroxide crystallisation
  • Crystallization mother liquor recycling
• High, 92% Li extraction from alpha spodumene and after calcination/soda leach and lithium hydroxide conversion.
• Test work results produced lithium hydroxide with the following impurity profile:

LiOH analyses - impurity levels in LiOH