Location of project
Geology & Mineralogy
The stockpiles comprise unweathered pegmatite material that was mined by open cut and hauled to a processing plant for extraction of cassiterite (tin concentrate) by gravity.
The mine produced about 33,000 tonnes of cassiterite concentrate between 1953 and 1990. Based on reported head grades and recoveries, total ore processed was between 20Mt and 30Mt.
The most common lithium minerals reported from the unzoned albite-rich Uis pegmatites are:
- Amblygonite (Li,Na)AlPO4(F,OH), contains 7.3-10.0% Li2O;
- Petalite LiAlSi4O10, contains 3.4-4.9% Li2O; and
- Spodumene LiAl (SiO3)2, contains 8% Li2O.
The pegmatites contain significant quantities of tantalum minerals, much of which is believed to remain in the stockpile along with about 30% of the original contained cassiterite.
The project was selected on the basis that it comprised an already defined large tonnage of mined and partly processed (fine crushed) unweathered lithium-bearing pegmatite stockpile.
Should drilling and metallurgical test-work confirm an acceptable recoverable grade, Tawana sees the potential for a low capex/opex operation due to:
- No mining required – which normally represents 30-60% of mine operating costs
- No ore haulage required
- No crushing required
- Limited (if any) need for grinding
- Low requirement of electricity and water