Charger Metals lifts lithium grades with ore sorting at Medcalf
Charger Metals reports strong metallurgical results from its Medcalf lithium deposit, lifting lithium and tantalum grades significantly while slashing iron content. The company’s recent 34% resource upgrade and proximity to processing infrastructure underpin plans for a scoping study.
- Ore sorting raises Li2O grade by 31% with 94.9% recovery
- Tantalum (Ta2O5) grade increases 34% with 97.2% recovery
- Iron content cut by 78% through sorting
- Medcalf Mineral Resource Estimate grows 34% to 10.6Mt
- Funding secured from Bynoe project sale for next-stage studies
Ore Sorting Delivers Significant Grade and Recovery Gains
Charger Metals NL (ASX:CHR) has unveiled compelling metallurgical test results from its Medcalf lithium deposit within the Lake Johnston Lithium Project, Western Australia. Ore sorting trials conducted by TOMRA’s X-Ray Transmission (XRT) technology boosted lithium oxide (Li2O) grades by 31%, lifting the grade from 1.01% to 1.32% while retaining an impressive 94.9% of lithium. Tantalum pentoxide (Ta2O5) grades similarly rose by 34%, reaching 147ppm with a 97.2% recovery rate.
Crucially, the ore sorting process knocked down the iron content by 78%, reducing Fe from 4.23% in the feed to just 1.27% in the combined concentrate. This iron rejection is vital since high iron levels can complicate downstream processing and reduce concentrate quality.
Moderate Crushing Energy and Excellent Liberation Support Processing
The metallurgical program also measured the crushing work index (CWi) at 7.55 kWh/tonne, placing it in the moderate energy consumption range. This suggests the ore is not overly hard to crush, an encouraging sign for processing costs. The ore exhibited excellent liberation characteristics, with little difference in sorting performance between coarse (+25mm) and finer (+10mm) fractions.
Resource Upgrade Reinforces Project Potential
These results complement the recent substantial Mineral Resource Estimate (MRE) upgrade at Medcalf, which now stands at 10.6 million tonnes at 1.0% Li2O and 107ppm Ta2O5, a 34% increase in contained lithium from the maiden resource published less than a year ago. The resource remains open at depth and along strike, suggesting further growth potential through ongoing drilling.
Charger’s Managing Director Bryan Dixon highlighted that the ore sorting success gives confidence in removing mining dilution from stacked pegmatites, a key factor in maintaining concentrate quality. The company is preparing to advance metallurgical testwork into dense media separation and heavy liquid separation stages to refine processing flowsheets.
Strategic Location and Funding Position
The Lake Johnston project benefits from proximity to four spodumene concentration plants within trucking distance and is about 200 kilometres from Esperance Port, facilitating logistics for concentrate shipment. The recent sale of Charger’s Bynoe Lithium Project to Core Lithium Limited has provided vital funding to support further drilling and mining studies at Lake Johnston.
Looking ahead, the company plans a scoping study to evaluate the economic viability of the project, leveraging the improved resource base and encouraging metallurgical outcomes. Mining methods are expected to combine open pit and underground approaches, with ore sorting playing a key role in dilution control.
Technical and Geological Insights
The Medcalf deposit sits within a geological setting of amphibolites and granite intruded by lithium- and tantalum-bearing pegmatites. The mineralisation is confined to these pegmatites, classified as LCT (Lithium-Cesium-Tantalum) types, with natural cut-offs around 0.3% Li2O and 65ppm Ta2O5. The company’s diamond drilling and sampling protocols adhere to industry standards, ensuring robust data quality for resource and metallurgical modelling.
Charger’s next metallurgical stages will focus on beneficiation via dense media separation and variability testing to optimise recovery and grade. These steps are critical to advancing the project towards feasibility and eventual production.
Bottom Line?
Charger Metals’ metallurgical advances and resource growth at Medcalf set the stage for a scoping study, but further testwork and mining studies remain key to confirming project economics.
Questions in the middle?
- How will Stage 2 and 3 metallurgical testwork impact processing flowsheet design and costs?
- What are the timelines and capital requirements for the upcoming scoping study?
- Can further drilling extend the resource beyond current limits and enhance project scale?
