Tectonic Metals posts 96% gold recovery at Flat gold project, Alaska

Tectonic Metals Inc. [TSXV: TECT; OTCQB: TETOF] reported results from the company’s first-ever scoping metallurgical heap leach column tests, which achieved impressive gold recoveries of 96% and 91%. These tests were conducted on coarse three-fourths-inch material comprising both oxidized and non-oxidized fresh mineralized drill core from Tectonic’s flagship Flat gold project, Alaska. The exceptional gold recoveries not only confirm the project’s heap leach potential but also set the stage for advancing toward run-of-mine heap leach processing.

Tony Reda, president and CEO, commented: “Our initial heap leach results mark a major milestone for the Flat gold project, a bulk-tonnage gold system showing continued strong geological similarities to Kinross Gold’s Fort Knox mine. In just two years of exploration at Flat, we have performed an extensive range of metallurgical tests, including heap leach column, conventional bottle roll, gravity separation, combined gravity and bottle roll, and flotation.

“These tests are crucial for evaluating and optimizing mining processing methods and derisking the project as we advance it towards a viable economic mining opportunity. Our results clearly demonstrate that the gold mineralization at Flat is not grind-sensitive, extremely low in sulphur, non-preg-robbing and well suited to various gold extraction techniques. Crushing and grinding typically are the largest capital cost and significant consumers of power at an operating mine, and therefore, the most expensive operational cost significantly impacting a mine’s all-in sustaining costs (AISC).

“With that in mind, we are now more than ever excited to explore the potential for run-of-mine heap leaching, similar to the Fort Knox mine. These metallurgical results underscore the potential for a cost-effective, large-scale mining operation in a stable jurisdiction, further establishing the Flat project as a key asset in Tectonic’s portfolio and the broader mining industry.”

Key findings and highlights: Exceptional gold recovery: 96% and 91% gold recoveries from coarse three-fourths-inch material, representing a mix of oxidized and non-oxidized fresh mineralization from nine drill holes from the Chicken Mountain intrusion.

Rapid leach kinetics: over 80% gold recovery was achieved within 29 days for the higher gold grade composite column and within 36 days for the slightly lower gold grade composite column.

Heap leach validated: column test results confirm the potential for heap leach processing at Flat, including both oxidized and non-oxidized fresh mineralization.

Non-oxidized fresh mineralized rock demonstrates amenable to heap leaching: results indicate that gold recoveries are not significantly influenced by the presence or absence of oxides, depth of mineralization and non-oxidized mineralization demonstrates amenability to heap leaching.

No agglomeration required: tests confirmed that agglomeration was not necessary, which has the potential to further enhance processing efficiency and lower costs.

Potential for run-of-mine heap leaching: metallurgical testing, including bottle rolls and column tests, indicates that the mineralization at Flat is not grind sensitive. Similar to the mineralization at the Fort Knox mine, gold at Flat is fracture-controlled, enabling efficient leach solution access and faster gold recovery even on coarse material. This style of gold mineralization is well suited for heap leaching, presenting a cost-effective extraction opportunity, particularly if uncrushed run-of-mine material is amenable to heap leaching as it is at Fort Knox.

Composite gold grades calculated (assay) and extracted along with metallurgical results include 95.7% gold recovery fpr high-grade composite ansd 90.9% gold recovery for low-grade composite.

Initial metallurgical characterization testwork on the Chicken Mountain mineralization was conducted by Tectonic in 2023 and complete results can be found on-line. These initial positive results of the various metallurgical tests indicate that Tectonic may have several metallurgical processing options for oxide and non-oxide fresh/sulphide mineralization present at Flat.