North Bay Resources Inc. (OTC:NBRI) reported an overall gold recovery rate of 97% from metallurgical studies at its Fran gold project in British Columbia.
The study demonstrated the potential for significant concentration upgrades and the use of advanced separation techniques, the company said in a statement.
Tests achieved a 67% gold recovery through gravity separation, which upgraded the head grade from 0.9 ounces per ton gold to 8.54 ounces per ton. Flotation tests recovered an additional 30%, producing a concentrate grade of 11.23 ounces per ton—a 12-fold increase from the initial grade.
Metallurgical studies involved multi-element analysis using advanced microwave digestion and plasma optical emission spectrometry. The process enabled precise quantification of metals including gold, copper, and zinc. Additional grind studies optimized material preparation for the gravity and flotation methods.
North Bay has completed the shipment of 120 tons of material from Fran to its Bishop Gold Mill in California. The shipment, consisting of 82 super-sacks weighing approximately 2,900 pounds each, is expected to yield high metal content, aligning with prior assay results indicating gold grades of 1.2–2.3 ounces per ton.
North Bay has also acquired new gravity separation equipment, including a Knudson Bowl centrifugal concentrator and a Gemini Table, to enhance primary recovery. Process engineers are optimizing equipment, including the Deister Table, to minimize dilution and increase recovery efficiency.
Located near Centerra Gold’s Mt Milligan Mine, the 34,360-acre Fran Gold property has seen over 50,000 feet of diamond drilling in 104 holes. The Bullion Alley Zone hosts a gold deposit stretching 3,700 feet, with gold veins grading up to 2.6 ounces per ton and wider zones of mid- to low-grade mineralization. Copper and silver have also been identified, with assays indicating grades up to 1.68% copper and 5.1 ounces per ton silver.
North Bay Resources plans to leverage its advanced metallurgical techniques and processing improvements to unlock the project’s full potential, with 5,000 tons of surface material ready for further evaluation and shipment.