Rapid Critical Metals (ASX:RCM) has completed X-ray transmission (XRT) ore-sorting test work on historical stockpiles at its Webbs Silver Project in New South Wales.
TOMRA tested two samples. Sample WPWHS comprised 21.8kg of historically processed waste material screened to 6–14mm, while sample WSHMM contained 553.8kg of unprocessed historical ore screened to 10–40mm.
The company used two XRT processing types. Contrast XRT classifies ‘high-density’ inclusions such as argentite and galena from host rock, while dual-energy XRT rejects base metal sulphides.
Each sample underwent two passes through the sorter. The first produced a ‘high-grade’ concentrate. Meanwhile, the second reprocessed waste from the initial run to generate middlings and waste fractions.
Results from the unprocessed ore sample were particularly strong. Material grading 565.26 grams per tonne silver (Ag) upgraded to 994g/t Ag, with 98% of contained Ag reporting to the concentrate and 44% mass rejection.
Processed waste samples also responded well. Silver grades increased from 164.6g/t Ag to 1,120g/t Ag in the first pass, with 94% of sample mass rejected as barren.
Managing Director Byron Miles says the results demonstrate the “potential for ore sorting to improve project economics”.
“The Webbs/Consol ore is very amenable to ore sorting, and the results are very positive for the project,” Miles says.
“We were particularly excited to see the results of the previously mined but unprocessed ore, with it almost doubling in grade without losing minimal ore.”
RCM says ore sorting can reject barren host rock before milling. This may reduce throughput, energy consumption, tailings storage requirements, and operating costs. At the same time, ore sorting enables a smaller processing plant footprint.
Miles says the results reflect the “well-liberated nature of sulphides” and the clear density differential between sulphides and waste.
Further test work is planned on drill core samples from current resource drilling. Rapid is also evaluating processing the historical material to generate potential cash flow.
Webbs holds an exploration licence called EL 5674 in New South Wales. Historical mining between 1884 and 1901 extracted approximately 55,000 tonnes of ore at an average grade of at least 23 ounces per tonne silver.
Rapid Critical Metals is a Sydney-based explorer focused on silver in New South Wales and gallium-germanium in Canada, with a fully funded, catalyst-rich exploration program underway.
Write to JC Villarba at Mining.com.au
Images: Rapid Critical Metals
