ITOGON, Benguet – The Itogon Suyoc Resources, Inc. (ISRI) reported that its Sangilo mine based in barangay Poblacion, here, was able to produce some 169,776 tons of ore with an average of 3.76 grams per ton last year compared to the 161,077 tons of ore with an average grade of 3.78 grams per ton in the previous year.
Further, the company’s mine development last year included 2,621 meters of off-vein advancement, 345 meters of on-vein development, and the rehabilitation of 256 meters of old drives compared to the 3,460 meters of off-vein development, 474 meters on-vein and 83 meters of old drive rehabilitation that the company achieved in 2023.
ISRI added that since 2023, significant advancements have optimized leaching processes in facility operations.
The company claimed that transitioning from carbon-in-pulp (CIP) to carbon-in-leach (CIL) has enabled simultaneous leaching and gold adsorption, reducing processing time, minimizing gold losses and significantly enhancing efficiency.
Moreover, carbon transfer methods were upgraded from airlifts to transfer pumps, expediting and streamlining operations.
According to ISRI, its mill has also transitioned from carbon leaching to carbon stripping and gold electrowinning, a more sustainable and scalable process that permits the reuse of activated carbon while reducing emissions.
ISRI explained that the aforesaid upgrade shifted production from gold buttons to dore bars, an alloy of gold and silver.
The company pointed out that additional enhancements include the installation of a D-6 hydro cyclone cluster to improve grinding discharge classification, the enlargement of the ball mill sump from 4 meters by 3 meters to 6 meters by 4 meters to enable higher milling rates and the reconditioning of a second 2-foot cone crusher to ensure continuous crushing during HP-1000 maintenance.
It stipulated that cyanide, caustic soda, and lime mixing tanks were also introduced for precise reagent preparation and supply, while new and replacement shell-in-tube heat exchangers significantly boosted carbon stripping efficiency.
ISRI emphasized that the said advancements greatly improved the efficiency and sustainability of leaching processes and facility operations through the years.
Last year, the total tons milled increased to 148,021 at an average mill head grade of 3.10grams per ton compared to 131,443 tons at 3.32 grams per ton in 2023.
ISRI said that gold recovery rose by 13 percent, reaching 13,132 ounces in 2024 compared to 11,607.57 ounces in 2023.
More importantly, ISRI asserted that stripping efficiency significantly improved from 81.16 percent in 2023 to 91.18 percent last year.
Specifically, the company disclosed that October 2024 marked a record high monthly production of 1,401 ounces where such advancements reflect enhanced processing capacity and operational efficiency, driving notable productivity gains. By Dexter A. See
