Understanding LCT pegmatites: design and recovery risks for lithium project teams
Reviewed by Tom Sullivan

First reported on MINING.com
30 Second Briefing
Lithium-cesium-tantalum pegmatite projects are being advanced on simplified grade models that ignore strong mineralogical zoning, with cases such as Mount Marion showing fine-grained spodumene and high mica contents can destabilise DMS media, depress concentrate grades and force costly plant retrofits. At Canada’s Tanco pegmatite, assuming a uniform 60:40 spodumene–quartz intergrowth and overlooking iron and phosphate phases contributed to inefficient plant design and shutdowns. Patriot Battery Metals’ Shaakichiuwaanaan feasibility study similarly relies on a 1D Li₂O recovery formula, without 3D modelling of mica, arsenic and antimony domains that could flag low-density clay-rich zones and DMS underperformance.
Technical Brief
- LCT pegmatites are inherently zoned, with mineralogy varying sharply between drill sections and mining panels.
- Basic Li assays give bulk grade only, masking textural differences that control DMS and flotation response.
- At Mount Marion, platy mica altered heavy‑medium density, physically entraining gangue and depressing concentrate quality.
- Tanco’s early 60:40 spodumene–quartz assumption ignored iron and phosphate phases that later constrained plant design.
- Metasomatic fluids carrying arsenic and antimony also degrade coarse spodumene into low‑density clays and fine micas.
Our Take
With lithium and broader critical minerals now a focus for African private equity teams such as the one highlighted in the 23 September 2026 piece on Chris Griffith, detailed LCT pegmatite characterisation in places like Mozambique and wider Africa will likely become a key screening tool for capital allocation rather than a nice-to-have study phase exercise.
The 60:40 spodumene–quartz intergrowth noted for the Tanco pegmatite underlines why many North American and Australian lithium projects in our database are now front-loading mineralogy and textural work; without this, flow-sheet risk and recovery assumptions for spodumene concentrates are proving materially unreliable at feasibility stage.
The use of 20 drill-core samples for mineralogical characterisation at the Shaakichiuwaanaan project is in line with what our coverage shows for early-stage LCT work in Canada and the US, but operators moving to PFS in Manitoba or Quebec increasingly supplement this with larger-scale variability testwork to avoid underestimating deleterious minerals such as micas, arsenic and antimony.
Prepared by collating external sources, AI-assisted tools, and Geomechanics.io’s proprietary mining database, then reviewed for technical accuracy & edited by our geotechnical team.
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