Inventus Mining Corp. has secured gold recoveries ranging from 66.9% to 74.5% in metallurgical heap leach tests conducted on material from its Pardo project near Sudbury, Ontario.

The test program, performed by Process Mineralogical Consulting Ltd., utilized a 310 kg composite of trench bulk sample material to evaluate gold extraction across three different crush sizes. The -1/4 inch crush size emerged as the most efficient, achieving a 74.5% recovery rate over 78 days. Notably, the data showed that recovery is front-loaded, with 72% of the gold extracted from the -1/4 inch material within 48 days. This specific size also maintained a favorable reagent profile, requiring no lime addition to keep the leach pH above 10.5 and demonstrating low total cyanide consumption.

“These results are very encouraging, demonstrating that Pardo mineralization is responsive to cyanide leaching and, importantly, that recovery is front-loaded. At a -1/4 inch crush, 72% of the gold was recovered in 48 days. This gives us a clear starting point to optimize cycle time, crush size and reagent consumption.”

— Wesley Whymark, CEO & Director

Inventus is now evaluating a flexible two-product processing concept for the site. Under this model, the company would use ore sorting to separate higher-grade material for off-site milling, while retaining lower-grade fractions on-site for potential heap leach processing. This approach aims to reduce the volume of material requiring transport and conventional milling, though the company noted that the current results are laboratory-scale and that heap leaching may not be the optimal route for higher-grade composites where maximum recovery is the primary objective.

The company is now moving toward further technical assessment to validate the viability of this integrated flowsheet. Upcoming work includes testing on representative lower-grade material and conducting ore-sorting studies to evaluate potential high-grade feed production. The team will also perform mineralogical and permeability studies to identify the specific controls on recovery for coarser particle sizes.

Inventus is currently trading at $0.265, up 10.42% for the day.

Read the full announcement: Inventus Reports Up to 75% Gold Recovery from Heap Leach Testwork at Pardo