In recent years, the Indian media has broken a number of stories on national TV about the discoveries of huge mineral resources, often reported as "reserves." There was this discovery of a huge 'reserve' of gold in the Sonbhadra district of UP in 2020, followed by another discovery of huge 'reserve' of gold in Bihar, a year later. The minister of mines also made an announcement about the latter in the Indian Parliament.
Unfortunately, all of these news stories originated in the government's exploration departments.
The latest in this series is a news story on the discovery of a huge ‘reserve’ (5.8 Million tonnes of Lithium) in the Jammu and Kashmir state associated with a Bauxite deposit.
The story caught the attention of the global exploration and mining community, unfortunately for the wrong reasons.
Firstly, most of lithium extracted worldwide is from liquid brine reservoirs beneath salt flats (salars), in southwestern South America and China.
The other major source of lithium is pegmatite hosted lithium ore deposits. These are often richer in lithium content than the salar brines. Although there are over 100 different minerals with some amount of lithium, only five (spodumene, lepidolite, petalite, amblygonite, and eucryptite) are mined.
However, extraction costs from pegmatite ore are nearly twice that of brines due to their mining, milling, and metallurgy costs.
The saleable product in both brine and pegmatite hosted mines is commonly Lithium carbonate.
Lithium is one of the secondary elements occurring in bauxite, where lithium content can reach up to 0.3% (as Li2O). Most Li in bauxitic ores is mainly hosted in illite, a clay mineral, whereas Li in aluminous claystone is mainly hosted in kaolinite, another clay mineral. Hectorite is a silicate of Na, Mg, and Li and contains about 0.5% Li. It is a member of the smectite family of clay minerals and is considered the most widespread among the Li-clay minerals. However, the extraction of Lithium from the clays is challenging and costly.
Jammu and Kashmir has a few small, isolated bauxite deposits. A 3-4 m thick bauxite deposit occurs in Salal area in the Reasi district. This is apparently developed over the Jangalgali Formation of Upper Cretaceous to Eocene age.
Exploration by the Geological Survey of India estimated an Inferred Resource of 5.9 million tonnes with an average SiO2 of 37% and Al2O3 of 45.3%. This is a high silica bauxite and will not be suitable for most alumina plants unless beneficiated. Among the trace elements analyzed, Li is reported to be 332 ppm.
This equates to a mere 2950 of contained metal. The saleable lithium carbonate equivalent is 15,703 tonnes. The uncertainties on the host mineral, the metallurgy, etc remain.
Obviously, this will not catapult India to the status of the second largest lithium-resource rich country, as claimed in the media. India needs to look elsewhere to power its huge battery requirements.
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