Pioneer Minerals reports a remarkable 17.6-fold upgrade in tungsten grade from historic tailings at its Springfield Tungsten Mine, advancing its North Pine Project in Idaho with promising metallurgical test results.
- Preliminary tests show tungsten grade upgrade up to 17.6 times
- High-grade concentrate of 3.27% WO3 produced via gravity separation
- Heavy liquid separation confirms dense tungsten mineral phases
- Tungsten enrichment concentrated in finer particle size fractions
- Ongoing metallurgical program supports future exploration and processing
Historic Tailings Reveal Hidden Tungsten Potential
Pioneer Minerals Ltd (ASX:PMM) has unveiled encouraging preliminary metallurgical results from composite samples of historic tailings at the Springfield Tungsten Mine, part of its North Pine Project in Idaho, USA. The test work, conducted by Mineral Technologies, demonstrates the potential to significantly upgrade tungsten grades from material previously considered waste.
The Springfield Mine, active in the 1950s, originally processed tungsten using gravity concentration methods that primarily recovered coarse tungsten minerals. The tailings tested represent the finer fraction left behind, which historically escaped recovery. Pioneer’s findings suggest this finer material still holds substantial tungsten value.
Impressive Grade Upgrades Using Conventional Methods
Through a series of beneficiation tests, including heavy liquid separation and Mozley gravity table processing, Pioneer achieved a tungsten concentrate grading approximately 3.27% WO3; equivalent to 32,713 ppm tungsten. This marks a 17.6-fold upgrade compared to the original tailings’ head grade. Heavy liquid separation further confirmed that tungsten minerals occur in dense phases, making them amenable to gravity-based recovery techniques widely used in global tungsten operations.
Size-by-assay analysis revealed that tungsten is preferentially concentrated in finer particle sizes, with grades nearly doubling in the finest fractions compared to the composite sample. This aligns with the historical processing approach, which focused on coarser particles, leaving finer tungsten minerals in the tailings.
Strategic Implications for North Pine Project
These metallurgical insights are pivotal for Pioneer’s broader North Pine Project. Understanding how fine-grained tungsten mineralisation behaves during processing informs future exploration and recovery strategies. The company is actively progressing site access improvements, conducting electromagnetic geophysical surveys to identify new mineralised zones, and preparing for drilling permits.
Additionally, Pioneer is pursuing potential funding from U.S. government programs, including Department of Defence initiatives aimed at strengthening domestic critical mineral supply chains. This could provide financial support to accelerate project development.
Next Steps and Market Outlook
While these results are preliminary and full recovery calculations await completion of mass balance and optimisation studies, they provide valuable technical validation for Pioneer’s ongoing metallurgical program. The company plans further mineralogical characterisation and beneficiation optimisation to refine processing strategies.
With tenure confirmation pending from the U.S. Bureau of Land Management, Pioneer’s progress in both technical and regulatory fronts positions the North Pine Project as a promising tungsten development opportunity in a critical minerals landscape.
Bottom Line?
Pioneer’s breakthrough in upgrading historic tailings could redefine the North Pine Project’s value and tungsten supply potential.
Questions in the middle?
- What will full recovery rates look like once optimisation and mass balance studies are complete?
- How will tenure confirmation by the Bureau of Land Management impact project timelines?
- What commercial scale processing strategies will Pioneer adopt to capitalise on fine-grained tungsten mineralisation?