Clean Air Metals Inc. announced that it has completed its follow-up metallurgical test program for the Thunder Bay North Critical Minerals Project. The metallurgical test program consisted of locked cycle tests on a variety of composite samples with a range of head grades from both the Current and Escape deposits and delivered recoveries of 70.2% to 80.9% Platinum (Pt) and 74.0% to 86.9% Palladium (Pd) and copper recoveries from 89.9% to 96.3%. The tests were completed by Base Metallurgical Labs under the guidance of DRA Global.

Copper-Nickel Separation circuit: Early flowsheet assessments focused on sequential flotation to create the two concentrates. However, optimal results were achieved with bulk flotation, followed by a copper-nickel separation flowsheet which resulted in improved overall recovery of metals. Sulphide minerals within the sample composites were sufficiently liberated at a grind size K80 of 65mm.

The process included bulk flotation with rougher and cleaner stages to create a sulphide-rich product hosting PGE, chalcopyrite, pentlandite, pyrite and pyrrhotite. This product was subsequently subjected to a regrind averaging a K80 of 20mm and then subjected to a high pH float to depress nickel bearing minerals and PGEs (PGE/Ni rich conc) and float copper bearing minerals (Cu rich conc). The program consisted of a total of 80 open circuit development tests and 8 locked cycle flotation (LCT) tests.

LCT test results highlighted the potential for the following: Recoveries as high as 80.9% platinum and 86.9% palladium; and Recoveries as high as 96.3% copper and up to 69.5% nickel and 84.3% gold. Preliminary modelled concentrate grade outlined the potential for a clean copper concentrate grading 22% Cu, 38 g/t Pt+Pd and a PGE Ni-rich concentrate grading 50 g/t Pt+Pd and 3.75% Ni. Through an engagement with Ocean Partners Inc., it was identified that projected concentrates produced were marketable with interest and indicative terms received from several domestic and overseas smelters.