North Bay Resources (OTC:NBRI) is gearing up to undertake exploration and prepare for additional shipments of ore from existing stockpiles at its Fran Gold Project in Canada.
Mobilisation is underway and crews will be on site in early June.
This comes after North Bay settled the second and third gold concentrate shipments from the project following processing at the company’s 100-ton-per-day Bishop Gold Mill in California.
Gold concentrate shipments in April to refinery partner Just Refiners in Reno, Nevada totaled 667 wet pounds.
Eight gross tons were processed in the second shipment and four gross tons were processed in the third.
North Bay reports an average recovered grade of 0.08 and 0.11 ounces per ton respectively reflecting a per ton value of US$260 ($404) and US$360 per ton, valuing the second shipment at US$1,836.88 and the third shipment at US$1,298.62.
The company says the low value per ton of the second shipment reflected a breakdown period of the raker/classifier where heavy and inconsistent grind size occurred.
Upgrades and repairs were made to the raker classifier throughout April, which North Bay says resulted in a greatly increased consistency and reduction in size of material feed to the centrifuge as well as a marked improvement in produced gold per ton between shipment two and three.
Following the upgrades, recoveries returned to within 10% of the first shipment.
North Bay is making progress on production optimisation with a flotation circuit design now finalised and an additional mixing tank being added to augment the flotation circuit.
The company is also increasing the grind size to further increase recoveries.
Previous metallurgical work determined that using a combined gravity and flotation circuit to process ore from the Fran Project can achieve recoveries of up to 97%.
North Bay plans to implement grade control on the stockpiles to increase per tonnage value and maximise head grade at the mill, while providing sufficient ore for continuous throughput.
The 34,360-acre Fran Project is located near two of North America’s largest new copper-gold mines – Centerra Gold’s (TSX:CG) 60,000-tonne-per-day Mt Milligan Copper-Gold Mine and Artemis Gold’s (TSX-V:ARTG) 334-million-tonne Blackwater Mine, both located in British Columbia, Canada.
North Bay has defined a gold deposit spanning over 1km in length, 100m in width and over 300m in depth within a known strike length of 1.7km.
The project hosts three to four parallel gold veins grading up to 2.6 troy ounces of gold per ton.
Past exploration and development at the Fran Project, including over 18,000m of diamond drilling, has shown large intercepts of mixed vein and disseminated gold.
North Bay’s focus is on ramping-up in preparation for increased deliveries of 100 tons per week in the short term and full commercial production of 100 tons per day thereafter.
Write to Angela East at Mining.com.au
Images: North Bay Resources
