Metallurgical test work at the Maalinao-Caigutan-Biyog (MCB) Copper-Gold Project has confirmed that high copper and gold recoveries are achievable in the first decade of mining, Celsius Resources Limited reported.
The tests, conducted by Brisbane Met Labs on ore samples from the first five years of mine life, showed consistent results across different ore types, validating the findings of previous test programs. The combined weighted average recoveries for the first ten years indicate copper recoveries of 95% and gold recoveries of 77%, according to the company.
“These conformity test results achieved are a strong outcome and further underpin the updated study and FEED economics for the initial ten years of mine life,” said Celsius Technical Director Peter Hume. “The results confirm the homogenous nature of the high-grade ore body and support consistent ore processing performance through the first decade of the mine’s operations.”
The metallurgical program included comminution and flotation recovery tests on core samples taken during the recent drilling campaign. The tests were designed to reconfirm the flowsheet used in the previous Feasibility Study and to support the production of a saleable copper-gold concentrate early in the mine life, in accordance with JORC Code requirements.
Results from rougher flotation tests indicated copper recoveries of approximately 98% and gold recoveries around 83% at a grind size of 150 microns. Cleaner flotation tests after regrinding to 38 microns produced a concentrate averaging 25% copper and 5 g/t gold. Reagent optimization tests showed potential improvement in gold recovery, and final weighted average recoveries after cleaner flotation were estimated at 95% for copper and 75% for gold.
“When combined with the results from the September 2021 test program covering years six to ten, the integrated average recoveries over the first decade of production are approximately 95% for copper and 77% for gold,” the company said.
This, the company added, confirms that a conventional copper flotation plant can consistently produce a high-quality copper-gold concentrate with very low deleterious elements, supporting robust economics over the first 10 years of operations.
The MCB Project, located in the Cordillera Administrative Region about 320 kilometers north of Manila, is the flagship project of Makilala Mining Company, Inc., Celsius’ Philippine affiliate. An updated JORC-compliant Mineral Resource Estimate announced in December 2022 identified 338 million tonnes of ore at 0.47% copper and 0.12 g/t gold, containing 1.6 million tonnes of copper and 1.3 million ounces of gold.
The previous Feasibility Study, released in December 2021, projected a 25-year mine life for an underground operation with a 2.28 Mtpa processing plant. The study estimated a post-tax net present value (8%) of US$464 million and an internal rate of return of 31%, assuming a copper price of US$4 per pound and gold at US$1,695 per ounce. Initial capital expenditure was pegged at US$253 million, with a payback period of roughly 2.7 years.
Celsius said ongoing studies to update the Feasibility Study and complete the Front-End Engineering and Design (FEED) are scheduled for completion by December 2025.
